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[Abstract] Serumspiegel der Immunglobuline bei gesunden Rauchern und Nichtrauchern mittleren Alters
(1993)
Kongreß für Laboratoriumsmedizin, Frankfurt 7. bis 9. 5. 1991. Abstracts der Posterpräsentation
(1991)
[Kongreßabstract] Opus®-Magnum, ein neues Analysensystem für Immunoassays. Ein Methodenvergleich
(1995)
[Poster-Abstract] Formel zur Beurteilung der Blut-Liquor-Schrankenfunktion bei älteren Patienten
(1998)
Diagnostische Probleme bei Infektionen in der Intensivmedizin und ihre therapeutischen Konsequenzen
(1983)
Delayed-onset muscle soreness (DOMS) is a common symptom in people participating in exercise, sport, or recreational physical activities. Several remedies have been proposed to prevent and alleviate DOMS. In 2008 and 2015, two studies have been conducted to investigate the effects of acupuncture on symptoms and muscle function in eccentric exercise-induced DOMS of the biceps brachii muscle. In 2008 a prospective, randomized, controlled, observer and subject-blinded trial was undertaken with 22 healthy subjects (22–30 years; 12 females) being randomly assigned to three treatment groups: real acupuncture (deep needling at classic acupuncture points and tender points; n = 7), sham-acupuncture (superficial needling at non-acupuncture points; n = 8), and control (n = 7). In 2015, a five-arm randomized controlled study was conducted with 60 subjects (22 females, 23.6 ± 2.8 years). Participants were randomly allocated to needle, laser, sham needle, sham laser acupuncture, and no intervention.
In both cases treatment was applied immediately, 24 and 48 hours after DOMS induction.
The outcome measures included pain perception (visual analogue scale; VAS), mechanical pain threshold (MPT), maximum isometric voluntary force (MIVF) and pressure pain threshold (PPT).
Results: In 2008, following nonparametric testing, there were no significant differences between groups in outcome measures at baseline. After 72 hours, pain perception (VAS) was significantly lower in the acupuncture group compared to the sham acupuncture and control subjects. However, the mean MPT and MIVF scores were not significantly different between groups. This lead to the conclusion, that acupuncture seemed to have no effects on MPT and muscle function, but reduced perceived pain arising from exercise-induced DOMS.
The more recent results from 2015 indicated that neither verum nor sham interventions significantly improved outcomes within 72 hours when compared with the no treatment control (P > 0.05).
Background: Transfusion of red blood cells (RBC) in patients undergoing major elective cranial surgery is associated with increased morbidity, mortality and prolonged hospital length of stay (LOS). This retrospective single center study aims to identify the impact of RBC transfusions on skull-base and non-skull-base meningioma patients including the identification of risk factors for RBC transfusion.
Methods: From October 2009 - October 2016 we retrospectively analyzed 423 primary meningioma patients undergoing surgery for primary meningioma resection our department.
Results: Of these 423 patients, 68 (16.1%) received RBC transfusion and 355 (83.9%) did not receive RBC units. Preoperative anaemia rate was significantly higher in transfused patients (17.7%) compared to patients without RBC transfusion (6.2%; p = 0.0015). In transfused patients, postoperative complications as well as hospital LOS was significantly higher (p < 00001) compared to non-transfused patients. After multivariate analyses, risk factors for RBC transfusion were preoperative American Society of Anesthesiologists (ASA) physical status score (p = 0.0247), tumor size (p = 0.0006), surgical time (p = 0.0018) and intraoperative blood loss (p < 0.001). Kaplan-Meier curves revealed significant influence on overall survival by preoperative anaemia, RBC transfusion, smoking, cardiovascular disease, preoperative KPS ≤ 60% and age (elderly ≥ 75 years).
Conclusion: We concluded that blood loss due to large tumors or localization near large vessels are the main triggers for RBC transfusion in meningioma patients paired with a potential preselection that masks the effect of preoperative anaemia in multivariate analysis. Further studies evaluating the impact of preoperative anaemia management for reduction of RBC transfusion are needed to improve clinical outcomes of meningioma patients.
Background: A growing interest exists in using polymeric nanoparticles (NPs) especially functionalized with surface-active substances as carriers across the blood brain barrier (BBB) for potentially effective drugs in traumatic brain injury (TBI). However, the organ distribution of intravenous administrated biodegradable and non-biodegradable NPs coated with different surfactants, how much of the administrated dose reach the brain parenchyma in areas with intact and opened BBB after trauma, as well as whether they elicit an inflammatory response is still to be clarified.
Methods: The organ distribution, brain penetration and eventual inflammatory activation of polysorbate-80 (Tw80) and sodium-lauryl-sulfate (SDS) coated poly l-lactide (PLLA) and perfluorodecyl acrylate (PFDL) nanoparticles were evaluated after intravenous administration in rats prior and after undergoing controlled cortical impact (CCI).
Results: A significant highest NP uptake at 4 and 24 hs was observed in the liver and spleen, followed by the brain and kidney, with minimal concentrations in the lungs and heart for all NPs. After CCI, a significant increase of NP uptake at 4 hs and 24 hs was observed within the traumatized hemisphere, especially in the perilesional area, although NPs were still found in areas away from CCI and the contralateral hemisphere in similar concentrations as in non-CCI subject. NPs were localized in neurons, glial and endovascular cells. Immunohistochemical staining against GFAP, Iba1, TNFα and IL1β demonstrated no glial activation or neuroinflamatory changes.
Conclusions: Tw80 and SDS coated biodegradable (PLLA) and non-biodegradrable (PFDL) NPs reach the brain parenchyma in both areas of traumatized and undamaged brain with disrupted and intact BBB, even though a high amount of them are retained in the liver and the spleen. No inflammatory reaction is elicited by these NPs within 24 hs after application. These preliminary promising results postulate the effectiveness and safety of these NPs as drug-carriers for the treatment of TBI.
Oral e-Poster Presentations - Booth 2: Neuro-Oncology C (Imaging&Monitoring), September 27, 2023, 1:00 PM - 2:30 PM
Background: Repetitive TMS (rTMS) can be used to non-invasively map cortical language areas. Commonly, frequencies of 5-10 Hz are used to induce speech errors. We could recently show that frequencies of 30 and 50 Hz are advantageous to achieve higher reliability. However, high-frequent rTMS applied over perisylvian regions still suffer from limited tolerability. Using short-train or paired-pulse TMS (pp-TMS) might offer a good alternative to rTMS to interfere with speech production. In this study, we, therefore, compared 30 Hz rTMS to pp-TMS aiming at improved language mapping.
Methods: 13 healthy, right-handed subjects (f=6, 25-41 years) were investigated using two different rTMS protocols: (i) 30 Hz rTMS and (ii) pp-TMS. TMS protocols were applied in a pseudo-randomized order during a picture naming task (picture-to-trigger interval: 0 ms) over cortical language areas. In a subsequent study, we compared pp-TMS also to short trains of three TMS pulses and repetitive paired pulse TMS. Language errors were post-hoc analysed by two independent raters and were assigned to eight different error categories. The level of pain was assessed on a subjective 0-10 numeric rating scale (NRS). Moreover, language error distribution was analysed using a cortical parcellation system.
Results: 30 Hz rTMS evoked a significantly higher number of errors than the pp-protocol, i.e., 18 ± 12 % vs. 10 ± 7 % (p<0.05). However, pp-TMS was significantly better tolerated with a mean NRS of 2.3 ± 1.6 vs. 3.4 ± 1.5 (p<0.05, FDR-corrected). Of note, pp-TMS could induce a higher number of anomias (15 ± 15 %) than repetitive TMS protocols (4 ± 7 %; p<0.1, FDR-corrected), but less dysarthria. The cortical distribution of errors differed between the two protocols. The results of train-of-three TMS were similar to the pp-TMS protocol.
Conclusions: Due to its better tolerability, pp-TMS might offer the possibility to stimulate regions which are particularly prone to direct facial / trigeminal nerve stimulation, e.g., the inferior frontal gyrus. Moreover, pp-TMS seems advantageous for mapping patients who are comparatively susceptible to rTMS side effects and with regard to safety in general.
Study Design: Cross-sectional survey
Objective: To determine the influence of surgeons’ level of experience and subspeciality training on the reliability, reproducibility, and accuracy of sacral fracture classification using the AO Spine Sacral Injury Classification System.
Summary of Background Data: An ideal classification system is easily comprehensible and reliable amongst the diverse group of surgeons. A surgeons’ level of experience may have a significant effect on the reliability and accuracy of a classification system. Moreover, surgeons of different subspecialities may have various levels of comfort with imaging assessment of sacral injuries required for accurate diagnosis and classification.
Methods: High-resolution computerized tomography (CT) images from 26 cases were assessed by 172 investigators from a diverse array of surgical subspecialities (general orthopaedics, neurosurgery, orthopaedic spine, orthopaedic trauma) and experience (<5, 5-10, 11-20, >20 years). Validation assessments were performed via web conference using high-resolution images, as well as axial/sagittal/coronal CT scan sequences. Two assessments were performed by each investigator independently three weeks apart in randomized order. Reliability and reproducibility were calculated with cohen’s kappa coefficient (k) and gold standard classification agreement was determined for each fracture morphology and subtype and stratified by experience and subspeciality.
Results: Respondents achieved an overall k = 0.87 for morphology and k = 0.77 for subtype classification, representing excellent and substantial intraobserver reproducibility, respectively. Respondents from all four practice experience groups demonstrated excellent interobserver reliability when classifying overall morphology (k=0.842/0.850, Assessment 1/Assessment 2) and substantial interobserver reliability in overall subtype (k=0.719/0.751) in both assessments. General orthopaedists, neurosurgeons, and orthopaedic spine surgeons exhibited excellent interobserver reliability in overall morphology classification and substantial interobserver reliability in overall subtype classification. Surgeons in each experience category and subspecialty correctly classified fracture morphology in over 90% of cases and fracture subtype in over 80% of cases according to the gold standard. Correct overall classification of fracture morphology (Assessment 1: p= 0.024, Assessment 2: p=0.006) and subtype (p2<0.001) differed significantly with surgeons with >20 years of experience demonstrating increased difficulty correctly classifying all fracture subtypes overall in comparison to the other experience groups. Correct overall classification did not significantly differ by subspecialty.
Conclusions: Overall, the AO Spine Sacral Injury Classification System appears to be universally applicable among surgeons of various subspecialties and levels of experience with acceptable reliability, reproducibility, and accuracy.
Disclosures: author 1: none; author 2: consultant=Medtronic, Nuvasive, ISD, Asutra, Stryker, Bioventus, Zimmer, teledocs, Clinical Spine Surgery, AOSpine ; author 3: none; author 4: grants/research support=AOSpine, consultant=DPS, icotec; author 5: none; author 6: none; author 7: grants/research support=DPS; author 8: none; author 9: grants/research support=NIH, RTI, CSRS, royalties=Inion ; author 10: stock/shareholder=Advanced Spinal Intellectual Properties; Atlas Spine; Avaz Surgical; Bonovo Orthopaedics; Computational Biodynamics; Cytonics; Deep Health; Dimension Orthotics LLC; Electrocore; Flagship Surgical; FlowPharma; Globus; Innovative Surgical Design; Insight Therapeutics; Jushi; Nuvasive; Orthobullets; Paradigm Spine; Parvizi Surgical Innovation; Progressive Spinal Technologies; Replication Medica; Spine Medica; Spineology; Stout Medical; Vertiflex; ViewFi Health, royalties=Aesculap; Atlas Spine; Globus; Medtronics; SpineWave; Stryker Spine,other financial report=AO Spine
Oral e-Poster Presentations - Booth 3: Spine 2 (Tumors), September 26, 2023, 4:10 PM - 4:50 PM
Background: Spinal metastasis remains a persistent and oftentimes urgent challenge in the neurosurgical operating room. We aim to understand metastatic spread to the spinal bone on a molecular level in endothelial cells and tumor cells to facilitate improved therapeutic approaches and diagnostics.
Methods: We established a murine syngeneic spinal bone metastasis model. In vivo dissemination was first evaluated using fluorescent beads, followed by murine cancer cell lines (B16, LLC1). We investigated short-term seeding and long-term growth to identify correlations between seeding and tumor formation. EphrinB2-Eph4 interaction has been described as a crucial mediator of spinal bone metastasis. Transient (pharmacological) and permanent (genetical) ephrinB2-Eph4 interventions were performed.
Results: Dissemination of microbeads to distinct spinal segments depended on segment and particle size. Disseminated tumor cells on the contrary showed less frequent arrest in the bone and equal distribution among segments. EphrinB2 intervention changed the dissemination behavior towards the lumbar segment. Interestingly, only transient intervention retained this distribution, permanent ephrinB2 depletion on endothelial cells (efnb2iΔEC) resulted in equal dispersion of metastases. Histological staining revealed a reduction of Endomucin (Emcn) positive structures in combination with a reduction of Type H (Emcn high/CD31 high) endothelial cells in naïve efnb2iΔEC animals. In tumor tissue, these Type H endothelial cells were unaffected. However, an increase in CD31-expressing endothelial cells was observed under endothelial ephrinB2 depletion. These CD31-expressing endothelial cells have been recently described as Type E (Emcn low/CD31 high) and implicated in angiogenesis and osteogenesis.
Conclusions: We here describe a subpopulation of endothelial cells in efnb2iΔEC mice that seems to resemble pro-angiogenic and possibly pro-adhesive type E endothelial cells. Based on these finding we propose a compensatory pro-angiogenic mechanism in efnb2iΔEC mice that is highjacking pre-existing developmental pathways, which is critical for late-stage spinal metastatic growth independent of the initial seeding and extravasation of metastatic cells.
Background: To investigate whether patients with critical emergency conditions are seeking or receiving the medical care that they require we characterized the reality of care for patients presenting with Neuro-emergencies during the first phase of the COVID-19 pandemic.
Methods: In this observational, longitudinal cohort study, all neurosurgical admissions that presented to our Department between February 1st and April 15th during the COVID-19 pandemic and during the same time-period in 2019 were identified and categorized according to the presence of a Neuro-emergency, the route of admission, management, and the category of disease. Further, the clinical course of patients with chronic subdural hematoma (cSDH) was investigated as a Neuro-emergency representative for a wide variety of semi-urgent symptoms.
Results: During the pandemic, the percentage of Neuro-emergencies among all neurosurgical admissions remained similar as in 2019 but a larger proportion presented through the emergency department than through the outpatient clinic or by referral (*p=0.009). The total number of Neuro-emergencies was significantly reduced (*p=0.0007) across all types of disease, particularly in severe vascular (*p=0.036) but also in spinal (*p=0.007) and hydrocephalus (*p=0.048) emergencies. Strikingly, elderly patients with cSDH and mild to moderate symptoms presented less frequently, with more severe symptoms (*p=0.046) and were less likely to reach favorable outcome (*p=0.003).
Conclusions: Despite pandemic-related restrictive measures and reallocation of resources, patients with Neuro-emergencies should be encouraged to present regardless of the severity of symptoms because deferred presentation may result in adverse outcome. Thus, conservation of critical healthcare resources remains essential in spite fighting COVID-19.
Objective: Nationwide data on the epidemiology, treatment characteristics, and long-term outcome of severe traumatic brain injury (TBI) in Germany is not yet existing. Neurosurgeons from the German Neurosurgery Society (DGNC) and traumatologists from the German Trauma Society (DGU), therefore, joined forces in 2016 to conceptualize a TBI module for the well-established Trauma Register of the DGU (TR-DGU). Here, we report how this “German National TBI registry (GNTR)” has been developed, implemented, and tested in a recently completed pilot period.
Methods: The conception and implementation process of the GNTR from August 2016 to February 2019 is described, and results of its 23-months long pilot period from February 2019 to December 2020 are presented. For the pilot period, TBI patients were prospectively enrolled at nine neurosurgical and traumatological hospitals across Germany. Inclusion criteria were treatment on the ICU ≥ 24h, or an ISS score ≥ 16. A variety of clinical, imaging, and laboratory parameters were collected, and the GOSE score was used to assess the outcome at discharge and 6- and 12 months follow-up.
Results: Details on the structure and dataset of the GNTR as well as milestones and pitfalls during its conception and implementation, are outlined. During the pilot period, a total of 264 TBI patients were enrolled. Their demographic characteristics, clinical, imaging, and radiological findings, and their early mortality and functional outcome are described. Furthermore, factors associated with an unfavorable outcome (GOSE 1-4) are assessed using uni- and multivariate regression analyses. Finally, problems and future directions of the GNTR are discussed.
Conclusion: The pilot period of the GNTR offers a first glance at the current epidemiology and treatment characteristics of TBI patients in Germany. More importantly, they show how a national TBI registry yielding high-quality prospective data can be developed, implemented, and tested within four years
Background: Dexamethasone (Dex) is the most common corticosteroid to treat edema in glioblastoma (GBM) patients. Recent studies identified the addition of Dex to radiation therapy (RT) to be associated with poor survival. Independently, Tumor Treating Fields (TTFields) provides a novel anti-cancer modality for patients with primary and recurrent GBM. Whether Dex influences the efficacy of TTFields, however, remains elusive.
Methods: Human GBM cell lines MZ54 and U251 were treated with RT or TTFields in combination with Dex and the effects on cell counts and cell death were determined via flow cytometry. We further performed a retrospective analysis of GBM patients with TTFields treatment +/- concomitant Dex and analysed its impact on progression-free (PFS) and overall survival (OS).
Results: The addition of Dex significantly reduced the efficacy of RT in U251 and MZ54 cells. TTFields (200 kHz/250 kHz) induced massive cell death in both cell lines. Concomitant treatment of TTFields and Dex did not reduce the overall efficacy of TTFields. Further, in our retrospective clinical analysis, we found that the addition of Dex to TTFields therapy did not influence PFS nor OS.
Conclusion: Our translational investigation indicates that the efficacy of TTFields therapy in patients with GBM and primary GBM cell lines is not affected by the addition of Dex.
Oral e-Poster Presentations - Booth 2: Spine 1 (Trauma&Misc), September 25, 2023, 10:00 AM - 10:40 AM
Background: Spondylodiscitis is a prevalent type of spinal infection, with pyogenic spondylodiscitis being the most common subtype. While antibiotic therapy is the standard treatment, some argue that early surgery can aid in infection clearance, improve survival rates, and prevent long-term complications such as deformities. However, others view early surgery as excessively risky. Due to the high mortality rate of up to 20%, it is crucial to determine the most effective treatment.
Methods: The primary objective of this study was to compare the mortality rate, relapse rate, and length of hospital stay for conservative and early surgical treatments of pyogenic spondylodiscitis, including determinants of outcomes. The study was registered on PROSPERO with the registration number CRD42022312573. The databases MEDLINE, Embase, Scopus, PubMed, and JSTOR were searched for original studies comparing conservative and early surgical treatments of pyogenic spondylodiscitis. The included studies were assessed using the ROBINS-1 tool, and eligible studies were evaluated using meta-analyses, influence, and regression analyses.
Results: The systematic review included 31 studies. The meta-analysis, which had a pooled sample size of 10,954 patients from 21 studies, found that the pooled mortality rate among patients treated with early surgery was 8%, while the rate was 13% for patients treated conservatively. The mean proportion of relapse/failure was 15% for patients treated with early surgery and 21% for those treated conservatively. Furthermore, the analysis concluded that early surgical treatment is associated with a 40% and 39% risk reduction in relapse/failure and mortality rates, respectively, when compared to conservative management. Additionally, early surgical treatment resulted in a 7.75-day reduction in length of hospital stay per patient (p<0.01). The most highly significant predictors of treatment outcome were found to be intravenous drug use, diabetes, the presence of an epidural abscess, positive cultures, location of infection, and age (p<0.001).
Conclusions: Overall, early surgical management was found to be consistently significantly more effective than conservative management in terms of relapse/failure and mortality rates when treating pyogenic spondylodiscitis, particularly for non-spinal epidural abscess spondylodiscitis.
The Ethics of Waiting lists and Rationing access to care (Ethics Parallel Session), September 26, 2023, 4:50 PM - 6:20 PM
Background: There has been a fivefold increase of neurosurgeons over the last three decades in Germany, despite a lesser increase in operations. Currently, there are approximately 1000 neurosurgical residents employed at training hospitals. Little is known about the overall training experience and career opportunities for these trainees.
Methods: In our role as resident representatives, we implemented a mailing list for interested German neurosurgical trainees. Thereafter, we created a survey including 25 items to assess the trainees’ satisfaction with their training and their perceived career prospects, which we then distributed through the mailing list. The survey was open from 1st April until 31st May 2021.
Results: 90 trainees were enrolled in the mailing list and we received 81 completed responses to our survey. Overall, 47% of trainees were very dissatisfied or dissatisfied with their training. 62% of trainees reported a lack of surgical training. 58% of trainees found it difficult to attend courses or classes and only 16% had consistent mentoring. There was an expressed desire for a more structured training programme and mentoring projects. In addition, 88% of trainees were willing to relocate for fellowships outside their current hospitals.
Conclusions: Half of the responders were dissatisfied with their neurosurgical training. There are various aspects that require improvement, such as the training curriculum, the lack of structured mentoring and the amount of administrative work. We propose the implementation of a modernized structured curriculum, which addresses the mentioned aspects, in order to improve neurosurgical training and, consecutively, patient care.
Introduction: The optimal treatment of patients with spinal infections remains a controversial topic. Within Europe, fundamentally different therapeutic concepts are found. Therefore, the aim of this study was to compare the outcome of patients who received surgical vs. antibiotic treatment alone for primary pyogenic spondylodiscitis in an international cohort analysis.
Materials and Methods: The retrospectively compiled databases of tertiary high-volume spine centers served as the baseline for this study. All documented cases of primary spondylodiscitis treated surgically and conservatively in the period of 2017-2022 were included and grouped according to the therapeutic concept: conservative vs. surgical treatment. Independent investigators collected the relevant clinical and radiological data. The primary endpoint of this study was mortality rate; secondary endpoints were relapse rate and persisting neurological deficit.
Results: A total of 392 patients were included in the analysis (155 females with a mean age of 68 years). Of these, 95 cases were treated conservatively (CoT) and 297 cases were treated surgically (SuT). There was no significant difference (p<0.01) related to patient’s disease characteristics: Lumbar was the main location (n=240, CoT 58/ SuT 182, p=0.97) followed by thoracic (n=70, CoT 24/ SuT 46, p=0,03) and cervical (n=47, CoT 7/ SuT 40, p=0.11) region. A multilocular spinal infection was present in 32 patients (CoT 3/ SuT 29, p=0.04). 181 cases (CoT 36/ SuT 145, p=0.06) presented with an epidural abscess. Neurological deficits were recorded in 100 cases (CoT 26/ SuT 74, p=0.63), and septic conditions in 88 cases (CoT 26/ SuT 62, p=0.19). Pre-existing conditions like Diabetes (p=0.57), renal failure (p= 0.97), hepatopathy (p= 0.15), malignoma (p=0.39) or i.v. drug abuse (p=0.93) did also not differ between the groups. The mortality rate of all conservatively treated was 24.2% (23 cases) and 6.7% (20 cases) in all surgically treated patients (p<0.001). A follow-up of ≥ 6 weeks was available in 289 cases (CoT 83, SuT 206 ). In this subset of patients relapse of infection occurred in six (7.2%) and 23 (11.2%) cases in the conservative and early surgical treatment group, respectively (p=0.69). Persisting neurological deficit was recorded in 21 (25.3%) of conservatively treated and 51 (24.8%) of surgically treated cases (p=0.92).
Conclusion: Whereas relapse rates and persisting neurological deficit were not found to differ significantly, the results of this international data analyses, with their respective limitations, clearly support the growing evidence of a significantly reduced mortality rate after surgical therapy for primary pyogenic spondylodiscitis when compared to conservative treatment regimen.
Spinal Tumors / Infections (Spine Parallel Session v.3), September 27, 2023, 8:30 AM - 10:00 AM
Background: The optimal treatment of patients with spinal infections remains a controversial topic. While there is some consensus regarding the indication for surgical intervention in infections with neurologic deficit, significant deformity or progressive disease, other situations remain controversial. Within Europe, fundamentally different therapeutic concepts are found. Therefore, the aim of this study was to compare the outcome of patients who received surgical vs. antibiotic treatment alone for primary pyogenic spondylodiscitis in an international cohort analysis.
Methods: The retrospectively compiled databases of tertiary high-volume spine centers served as the baseline for this study. All documented cases of primary spondylodiscitis treated surgically and conservatively in the period of 2017-2022 were included and grouped according to the therapeutic concept: conservative vs. surgical treatment. Independent investigators collected the relevant clinical and radiological data. The primary endpoint of this study was mortality rate; secondary endpoints were relapse rate and persisting neurological deficit.
Results: A total of 392 patients were included in the analysis (155 females and 237 males with a mean age of 68 years). Of these, 95 cases were treated conservatively (CoT) and 297 cases were treated surgically (SuT). Most of conservatively treated patients were treated in the United Kingdom (CoT 81/ SuT 7), while most of the surgically treated cases were treated in Germany (CoT 14/ SuT 290). There was no significant difference (p<0.01) related to patient’s disease characteristics:
Lumbar was the main location (n=240, CoT 58/ SuT 182, p=0.97) followed by thoracic (n=70, CoT 24/ SuT 46, p=0,03) and cervical (n=47, CoT 7/ SuT 40, p=0.11) region. A multilocular spinal infection was present in 32 patients (CoT 3/ SuT 29, p=0.04). 181 cases (CoT 36/ SuT 145, p=0.06) presented with an epidural abscess. Neurological deficits were recorded in 100 cases (CoT 26/ SuT 74, p=0.63), and septic conditions in 88 cases (CoT 26/ SuT 62, p=0.19). Pre-existing conditions like Diabetes (CoT 20/, SuT 71, p=0.57), renal failure (CoT 19/ SuT 60, p= 0.97), hepatopathy (CoT 4/ SuT 26, p= 0.15), malignoma (CoT 9/ SuT 38, p=0.39) or i.v. drug abuse (CoT 5/, SuT 15, p=0.93) did also not differ between the groups.
The mortality rate of all conservatively treated was 24.2% (23 cases) and 6.7% (20 cases) in all surgically treated patients (p<0.001). A follow-up of ≥ 6 weeks was available in 289 cases (CoT 83, SuT 206 ). In this subset of patients relapse of infection occurred in six (7.2%) and 23 (11.2%) cases in the conservative and early surgical treatment group, respectively (p=0.69). Persisting neurological deficit was recorded in 21 (25.3%) of conservatively treated and 51 (24.8%) of surgically treated cases (p=0.92).
Conclusions: Whereas relapse rates and persisting neurological deficit were not found to differ significantly, the results of this international data analyses, with their respective limitations, clearly support the growing evidence of a significantly reduced mortality rate after surgical therapy for primary pyogenic spondylodiscitis when compared to conservative treatment regimen.
Introduction: Spondylodiscitis is the commonest form of infectious disease of the spine and harbours a high mortality rate of up to 20%. Recent demographic trends in Germany, such as an aging population, immunosuppression, and intravenous drug use, suggest that the incidence of spondylodiscitis may be on the rise. However, the exact epidemiological development of the disease remains uncertain. This study aims to analyse the burden on the tertiary healthcare system in Germany using data from the Federal Statistical Office of Germany (FSOG) database.
Materials and Methods: All cases of spondylodiscitis diagnosed between 2005 and 2021 were identified from the FSOG database. The study characterised the mean duration of hospital stays, total and population-adjusted number of diagnoses made, age-stratified incidence, and outcomes of hospitalised patients.
Results: A total of 131,982 diagnoses for spondylodiscitis were identified between 2005 and 2021. The number of diagnoses for spondylodiscitis has doubled during this period, from 5.4/100,000 population in 2005 to 11/100,000 population in 2021. The highest increase in admissions was recorded for those aged 90 years and above (+1307%), 80-89 (+376%) and 70-79 (+99%). Hospital discharges to rehabilitation facilities have increased by 160%, and discharges against medical advice by 91%. On the other hand, during the analysed period, the in-hospital mortality rate has decreased by 52%.
Conclusion: The population-adjusted incidence of spondylodiscitis in Germany has more than doubled between 2005 and 2021, highlighting the clinical relevance of this disease. During the same period, in-hospital mortality dropped by half. These findings suggest the need for further investigation into optimal therapy, particularly the role and timing of surgical treatment.
Background: Epileptic seizures are common clinical features in patients with acute subdural hematoma (aSDH); however, diagnostic feasibility and therapeutic monitoring remain limited. Surface electroencephalography (EEG) is the major diagnostic tool for the detection of seizures but it might be not sensitive enough to detect all subclinical or nonconvulsive seizures or status epilepticus. Therefore, we have planned a clinical trial to evaluate a novel treatment modality by perioperatively implanting subdural EEG electrodes to diagnose seizures; we will then treat the seizures under therapeutic monitoring and analyze the clinical benefit.
Methods: In a prospective nonrandomized trial, we aim to include 110 patients with aSDH. Only patients undergoing surgical removal of aSDH will be included; one arm will be treated according to the guidelines of the Brain Trauma Foundation, while the other arm will additionally receive a subdural grid electrode. The study's primary outcome is the comparison of incidence of seizures and time-to-seizure between the interventional and control arms. Invasive therapeutic monitoring will guide treatment with antiseizure drugs (ASDs). The secondary outcome will be the functional outcome for both groups as assessed via the Glasgow Outcome Scale and modified Rankin Scale both at discharge and during 6 months of follow-up. The tertiary outcome will be the evaluation of chronic epilepsy within 2-4 years of follow-up.
Discussion: The implantation of a subdural EEG grid electrode in patients with aSDH is expected to be effective in diagnosing seizures in a timely manner, facilitating treatment with ASDs and monitoring of treatment success. Moreover, the occurrence of epileptiform discharges prior to the manifestation of seizure patterns could be evaluated in order to identify high-risk patients who might benefit from prophylactic treatment with ASDs.
Trial registration: ClinicalTrials.gov identifier no. NCT04211233.
Propranolol as a potentially novel treatment of arteriovenous malformations: from bench to bedside
(2022)
Background: Propranolol is a non-selective blocker of the β-adrenergic receptor and has been used for treatment of proliferative infantile hemangiomas. The vasoconstrictive and antiangiogenic effects of propranolol led us to explore its potential application for the treatment of AVMs.
Methods: AVM tissue was cultured after surgical resection in the presence of 100μM propranolol or solvent DMSO. After incubation for 72 hours, tissue was harvested for testing. The expression levels of SDF1α, CXCR4, VEGF and HIF-1 was measured by rt-PCR. Furthermore, data of patients in 2 vascular centres harboring AVM was retrospectively interrogated for a time period of 20 years. The database included information about hemorrhage, AVM size and antihypertensive medication. Descriptive analyses were performed, focusing on the risk of hemorrhage, size of the lesion at presentation and clinical follow-up in patients on β-blocker medication versus those who were not.
Results: Among 483 patients, 73 (15%) were under β-blocker-treatment. 48% AVMs presented with hemorrhage at diagnosis. Patients under β-blocker-treatment had a lower risk of hemorrhage at the time of diagnosis in a univariate analysis (p<0,0001;OR13). Patients under β-blocker-treatment showed a significant higher chance for a lower Spetzler-Martin-grade ≤III (p<0,0001;OR6,5) and a lower risk for the presence of an associated aneurysm (p<0,0001;OR3,6).
Multivariate analysis including Spetzler-Martin-Grading, young age ≤50, presence of associated aneurysm and β-blocker-treatment showed reduced risk for hemorrhage under β-blocker-treatment (p<0,01,OR0,2).
The expression of CXCR4 was suppressed by propranolol most likely through the HIF-1-pathways. The gene-expression of vasculogenesis factors was decreased in with propranolol incubated AVMs.
Conclusion: β-Blocker medication seems to be associated with a decreased risk of AVM-related hemorrhage and AVM-size at presentation or during follow-up. Propranolol inhibits SDF1α-induced vasculogenesis by suppressing the expression of CXCR4 most likely through the HIF-1-pathways. Therefore, SDF1α/CXCR4 axis plays an important role in the vasculogenesis and migration of inflammatory cells in AVM lesions.
Background: Following elective craniotomy patients routinely receive monitoring on ICU. However, the benefit of ICU monitoring in these patients is discussed controversially. Due to the current COVID-19 pandemic, there are further limitations of ICU capacities. This study aimed to compare this strategy with a standardized management of post-craniotomy patients on ICU.
Methods: Two postoperative strategies were compared in a matched-pair analysis: The first cohort included patients treated between May-August 2021 according to the “No ICU – unless” concept (NIU group), where patients were managed on the normal ward postoperatively. The second cohort contained patients routinely admitted to the ICU between February-April 2021 (control group). Outcome parameters contained complications, length of stay, duration to first postoperative mobilization, number of unplanned imaging, number/type of ICU interventions and pre- and postoperative mRS. Patient characteristics were analyzed using electronic medical records.
Results: The NIU group consisted of 96 patients, the control group of 75 patients. Complication rates were comparable in both cohorts (16% in NIU vs. 17% in control; p=0.123). Groups did not differ significantly in the number of imaging (10% in NIU vs. 13% in control; p=0.67), in the type of interventions on ICU (antihypertensive therapy 5% (NIU) vs. 6% (control); p=0.825) or in the time to first postoperative mobilization (average 1.1± 1.6 days vs. 0.9± 1.2 days; p=0.402). Length of hospital stay was shorter in the NIU group without reaching statistical significance (average 5.8 vs. 6.8 days; p=0.481). There was no significant change in the distribution of preoperative (p=0.960) and postoperative (p=0.425) mRS scores.
Conclusion: Postoperative ICU management does not reduce postoperative complications and has no effect on the surgical outcome of elective craniotomies. The majority of postoperative complications are detected after a 24-hour observation period. This approach may represent a potential strategy to prevent overutilization of ICU capacities while maintaining sufficient postoperative care for neurosurgical patients.
Introduction: Lumbosacral fixation is a common procedure in primary and revision spine surgery but leads to high biomechanical stress on adjacent segments and the SIJ, resulting in implant failure such as breakage and loosening and pain. This frequently results in further surgery. For patients showing clinical and radiological signs of SIJ affection/arthrosis who fail conservative therapy, transarticular lumbopelvic fusion via the SIJ may be considered. The Bedrock™ technique has been described as a new option for reinforced lumbopelvic fixation, fusing the SIJ with additional triangular titanium implants, thereby reducing biomechanical loads off the S2AI screws. We share our experiences with 19 patients treated with this technique since January 2019.
Materials and Methods: 19 patients suffering from persisting low back pain (LBP) with indication for reinforced lumbopelvic fixation and SIJ fusion were treated with reinforced lumboplevic fixation with S2AI screw and a triangular titanium implant. 14 cases were revisions. All surgeries were carried out by a single surgeon at a orthopedic university hospital. Data was gathered retrospectively.
Results: From 1/2019 - 9/2021 19 patients (11f, 8m) were treated with reinforced lumbopelvic fixation and SIJ fusion with a mean follow up of 18,2 months. Mean age 68 years (range 62-78y). Preop. walking distance was reduced to an average <100 m. Standard treatment involved S2AI screws and triangular titanium implants (SIBone, iFuse 3D™). 14 revision cases split into 5 low grade infections with screw loosening, 3 cases with rod breakage, 5 cases of painful lumbopelvic screw prominence, 7 cases with proximal junctional kyphosis, 2 cases with misplaced implants, 8 cases of poor bone mineral density. 5 patients without prior spine surgery. All patients were treated bilaterally using freehand technique. Average implant length was 65 mm. There were no intraoperative or implant associated adverse events (AE) or serious adverse events (SAE). Postoperative imaging demonstrated good implant positioning and function. All patients regained walking ability for distances > 1000 m and were satisfied with the result. All patients reported significant reduction of SIJ pain.
Conclusion: We report results of 19 patients with a reinforced lumbopelvic fixation and fusion by S2AI screws augmented by one parallelly placed triangular titanium implant fusing the SIJ bilaterally with a mean follow-up of 18.2 months. Intra- and postoperatively we experienced no implant associated adverse event. Patients regained significant walking ability and significant reduction of SIJ pain. Radiologically no signs of implant loosening or failure were detected at the end of follow-up. Our results demonstrate a safe and efficacious surgical technique for reinforced lumbopelvic fixation with fusion of SIJ with significant improvement of the health care related quality of life. Further studies need to be conducted in order to obtain additional evidence.
Background: During the COVID-19 pandemic, decreased volumes of acute stroke admissions were reported. We aimed to examine whether subarachnoid hemorrhage (SAH) volumes demonstrated similar declines in our department. Furthermore, the impact of pandemic on disease progression should be analyzed.
Methods: We conducted a retrospective study in neurosurgical department of university hospital Frankfurt including patients with the diagnosis of aneurysmal SAH during the first year of COVID-pandemic. One year cumulative volume for SAH hospitalization procedures were compared to the one-year period before (03/2020–02/2021 versus 03/2019–02/2020) and the last 5 pre-COVID-pandemic years (2015-2020). All relevant patient characteristics concerning family history, disease history, clinical condition at admission, active/past COVID-infection, treatment management, complications and outcome were analyzed.
Results: There was a decline in SAH hospitalizations, with 84 admissions in the year immediately before and 56 admissions during the pandemic, without reaching a significance. No significant difference in analyzed patient characteristics including clinical condition at onset, treatment, complications and outcome, between 56 SAH patients admitted during COVID pandemic and treated patients in the last 5 years in pre-COVID period were found. Using a multivariable analysis, we detected young age (p<0.05;OR4,2) and no existence of early hydrocephalus (p<0.05;OR0,13) as important factors for a favorable outcome (mRS≤0-2) after aSAH during the COVID-pandemic. A past COVID-infection was detected in young patients suffering from aSAH (Age< 50years, p<0.05;OR10,5) with increased rate of cerebral vasospasm after SAH onset (p<0.05;OR26). Nevertheless, past COVID-infection did not reach a significance as a high risk factor for unfavorable outcome.
Conclusion: There was a relative decrease in the volume of SAH during the COVID-19 pandemic. Despite of extremely different conditions of hospitalization, there was no impairing significant effect on treatment and outcome of admitted SAH patients. A past COVID-infection seemed not to be a relevant limiting factor concerning favorable outcome.
Background: Unruptured intracranial aneurysm (UIA) poses a therapeutic dilemma in which the risk-benefit analysis of invasive intervention has to be balanced against the natural history of the disease. To date, there is no medical treatment to prevent aneurysm development and subsequent progression to rupture. We explored the vitamin D system because of its known anti-inflammatory and anti-tissue-remodeling effect as a potential treatment for UIA.
Methods: 25-vitaminD3 levels tested between 2008-2016 and data of SAH patients admitted during the months with a peak versus nadir of VitD3-values were analyzed, retrospectively. We prospectively correlated VitD3 with size and number of aneurysms at the rupture time in patients admitted between 2017-2019. An experimental mice shear stress model and cell culture model were used to investigate the effect of 1,25-dihydroxy-vitaminD3 (1,25-VitD3) and acting mediators in this mechanism.
Results: Based on the retrospective analysis demonstrating an increased frequency of aneurysm rupture rate in patients during the low vitamin D period in winter, we started the prospective study evaluating plasma vitamin D levels at admission. VitD levels were inversely correlated with aneurysm size as well as number of aneurysms. Low number of aneurysms was significantly associated with sufficient plasma Vitamin D level as an independent factor in a multivariate analysis.
From bedside back to bench, active 1,25-VitD3 hormone attenuated the natural history of remodeling in mice basilar artery. Deletion of the vitamin-D-receptor in myeloid cells decreased the protective 1,25-VitD3 effect. Cell-culture of vascular fibroblasts confirmed the anti-tissue remodeling effect of 1,25-VitD3.
Conclusion: 1,25-VitD3 attenuates aneurysm development and subsequent progression to rupture. However, VitD-administration should be tested as optional treatment in management of patients with UIA.
Oral e-Poster Presentations - Booth 1: Vascular 3, September 27, 2023, 10:00 AM - 10:40 AM
Background: Despite current clinical guidelines recommending suboccipital decompressive craniectomy (SDC) in patients with space-occupying cerebellar infarction when neurological deterioration occurs, the precise definition of such deterioration remains unclear. The current study aimed at characterizing whether clinical outcomes can be predicted by the GCS score immediately prior to SDC, and whether higher GCS scores are associated with better clinical outcomes. We aimed to characterize whether clinical outcomes can be predicted by the GCS score immediately prior to SDC, and if higher GCS scores are associated with better clinical outcomes.
Methods: In a single-center, retrospective analysis of 51 patients treated with SDC for space-occupying cerebellar infarction clinical and imaging data were evaluated at the timepoints of symptom onset, hospital admission and preoperatively. Clinical outcome was measured by mRS at the last available follow-up. Preoperative GCS scores were stratified into three groups (GCS 3-8, 9-11 and 12-15). Univariate and multivariate Cox regression analyses were performed using clinical and radiological parameters as predictors of clinical outcome.
Results: In Cox-regression analysis using mRS of 1-2 as a positive clinical outcome we found a significant increase in the proportional hazard ratio (HR) of 6.581 [CI 1.839-36.414]; p=0.031 for GCS scores of 12-15 prior to SDC. Clinical outcomes (mRS 3-6) were associated with infarct volume above 6.0 cm3 (HR 2.473 [CI 1.209-5.057]; p=0.013), tonsillar herniation (HR: 0.279 [CI 0.083-0.933]; p=0.038), brainstem compression (HR 0.304 [CI 0.123-0.749]; p=0.010) and a preoperative GCS score of 3-8 (HR 2.386 [CI 1.160-4.906]; p=0.018).
Conclusions: SDC should be considered in patients with infarct volumes above 6.0 cm3 with GCS scores higher than previously described in the literature, as these patients may show better long-term outcome than those in which surgery is delayed until a GCS score of 11 or lower.
Background: Dysphagia is a common and severe symptom of traumatic brain injury (TBI) affecting up to 78% of patients. It is associated with pneumonia, increased morbidity and mortality. Although subdural hematoma (SDH) accounts for over 50% of TBI, the occurrence of dysphagia in this subtype has not been investigated. This study investigates the overall frequency, clinical predictors of dysphagia and functional outcome of patients with SDH associated dysphagia.
Methods: All patients presenting in author ́s institution between 2007 and 2020 with SDH were included in the study. Patients with SDH and clinical suspicion for dysphagia received a clinical swallowing assessment by a speech and language pathologist (SLP). Furthermore the severity of dysphagia was rated according to swallowing disorder scale.Functional outcome was evaluated by Glasgow outcome scale (GOS).
Results: Of 545 patients with SDH, 71 patients had dysphagia (13%). The prevalence of dysphagia was significantly lower in the surgical arm compared to the conservative arm (11.8% vs 21.8%; OR 0.23; p=0.02). Independent predictors for dysphagia were GCS <13 at admission (p<0.001; OR 4.17), cardiovascular disease (p=0.002; OR 2.29) and pneumonia (p=0.002; OR 2.88) whereas operation was a protective factor (p<0.001; OR 0.2). All patients with dysphagia improved significantly under SLP treatment from initial diagnosis to hospital discharge (p<0.01). However, patients with most severe grade of dysphagia showed no significant improvement during the clinical course. Patients with dysphagia had significantly worse outcome (GOS 1-3) compared to those without dysphagia (48.8% vs 26.4%; p<0.001).
Conclusion: Dysphagia is a frequent symptom in SDH and the early identification of dysphagia is crucial regarding initiation of treatment and functional outcome. Surgery is effective in preventing dysphagia and should be considered in high-risked patients.
Background: Research on chronic subdural hematoma (cSDH) management has primarily focused on potential recurrence after surgical evacuation. Herein, we present a novel postoperative/non-invasive treatment that includes a supervised Valsalva maneuver (SVM), which may serve to reduce SDH recurrence. Accordingly, the aims of the study were to investigate the effects of SVM on SDH recurrence rates and functional outcomes.
Methods: A prospective study was conducted from December 2016 until December 2019 at the Goethe University Hospital Frankfurt. Of the 204 adult patients with surgically treated cSDH who had subdural drains placed, 94 patients were assigned to the SVM group and 82 patients were assigned to the control group. The SVM was performed by having patients blow into a self-made SVM device at least two times/h for 12 h/day. The primary end-point was SDH recurrence rate, while secondary outcomes were morbidity and functional outcomes at 3 months of follow-up.
Results: SDH recurrence was observed in 16 of 94 patients (17%) in the SVM group, which was a significant reduction as compared with the control group, which had 24 of 82 patients (29.3%; p = 0.05) develop recurrent SDHs. Further, the infection rate (e.g., pneumonia) was significantly lower in the SVM group (1.1%) than in the control group (13.4%; p < 0.001; odds ratio [OR] 0.1). At the 3-month follow-up, 85 of 94 patients (90.4%) achieved favorable outcomes in the SVM group compared with 62 of 82 patients (75.6%) in the control group (p = 0.008; OR 3.0). Independent predictors for favorable outcome at follow-up were age (OR 0.9) and infection (OR 0.2).
Conclusion: SVM appears to be safe and effective in the post-operative management of cSDHs, reducing both recurrence rates and infections after surgical evacuation, thereby resulting in favorable outcomes at follow-up.
Background: The extent of preoperative peritumoral edema in glioblastoma (GBM) has been negatively correlated with patient outcome. As several ongoing studies are investigating T-cell based immunotherapy in GBM, we conducted this study to assess whether peritumoral edema with potentially increased intracranial pressure, disrupted tissue homeostasis and reduced local blood flow has influence on immune infiltration and affects survival.
Methods: A volumetric analysis of preoperative imaging (gadolinium enhanced T1 weighted MRI sequences for tumor size and T2 weighted sequences for extent of edema (including the infiltrative zone, gliosis etc.) was conducted in 144 patients using the BrainlabÒ software. Immunohistochemical staining was analyzed for lymphocytic- (CD 3+) and myeloid (CD15+) tumor infiltration. A retrospective analysis of patient-, surgical-, and molecular characteristics was performed using medical records.
Results: The edema to tumor ratio was neither associated with progression-free nor overall survival (p=0.90, p=0.74). However, GBM patients displaying IDH-1 wildtype had significantly higher edema to tumor ratio than patients displaying an IDH-1 mutation (p=0.01). Immunohistopathological analysis did not show significant differences in lymphocytic or myeloid tumor infiltration (p=0.78, p=0.74) between these groups.
Conclusion: In our cohort, edema to tumor ratio had no significant correlation with immune infiltration and outcome. However, patients with an IDH-1wildtype GBM had a significantly higher edema to tumor ratio compared to their IDH-1 mutated peer group. Further studies are necessary to elucidate the underlying mechanisms.
Introduction: Ferroptosis has recently been identified as a form of programmed cell death caused by an accumulation of lipid reactive oxygen species (ROS). However, little is yet known about the role in hepatocellular carcinoma (HCC) and its signalling mechanism as well the modulation of ROS.
Material and methods: Human HCC cell lines were treated with different concentrations of ROS modulators (Auranofin, Erastin, BSO). Cell death was determined by analysis of PI-stained nuclei using flow cytometry. ROS production and lipid peroxidation were analysed at early time points before cell death starts. For mechanistic studies we performed Western Blot and a Proteome array. Different inhibitors of cell death target proteins, ROS-scavengers as well as lipoxygenase inhibitors were used. To investigate the functional relevance of NAPDH oxidases (NOX) 1 and 4 for ROS modulation and ferroptosis we genetically silenced its genes using three distinct siRNAs and we used the NOX1/4-inhibitor GKT137831.
Results and discussions: Compared to the single treatment, Auranofin/BSO-cotreatment as well as Erastin/BSO-cotreatment acted in concert to trigger cell death and to reduce cell viability of HCC cells in a dose- and time-dependent manner. Furthermore, both cotreatments induce ROS production, lipid peroxidation and ferroptotic cell death, which could be inhibited by the use of Ferrostatin-1 (inhibitor of lipid peroxidation) and Liproxstatin-1 (specific inhibitor of ferroptosis). The broad-range caspase inhibitor zVAD.fmk failed to rescue cells from Auranofin/BSO- or Erastin/BSO-cotreatment induced cell death. No activation of caspases-3 could be seen in the proteome profiler apoptosis assay. Importantly, the selective lipoxygenase (LOX) inhibitor Baicalain and the pan-LOX inhibitor NDGA protect HCC cells from Auranofin/BSO- and Erastin/BSO-cotreatment stimulated lipid peroxidation, ROS generation and cell death, indication that the induction of ferroptosis may bypass apoptosis resistance of HCC cells. Mechanistic studies showed that Auranofin/BSO-cotreatment decreased TrxR-activity, led to Nrf2 accumulation and promoted the activation of HO-1. In contrast, NOX 1 and 4 were involved in Erastin/BSO-mediated cell death and the use of the NOX1/4-inhibitor GKT137831 rescued HCC cells from the Erastin/BSO-induced cell death.
Conclusion: By providing new insights into the molecular regulation of ROS and ferroptosis, our study contributes to the development of novel treatment strategies to reactivate programmed cell death in HCC cells.
Background: The most frequent therapy of hydrocephalus is the implantation of ventriculoperitoneal shunts for diverting cerebrospinal fluid from the ventricles into the peritoneum. We compared two adjustable valves, the proGAV and proGAV 2.0, for complications which resulted in revision operations.
Methods: Four hundred patients who underwent primary shunt implantation between 2014 and 2020 were analyzed for overall revision rate, one-year revision rate, revision free survival and overall survival observing patient age group, gender, etiology of hydrocephalus, implantation site, prior diversion of cerebrospinal fluid and cause of revision.
Results: All data were available of all 400 patients (female/male 208/192). Overall, 99 patients underwent revision surgery after primary implantation. ProGAV valve was implanted in 283 patients, proGAV 2.0 in 117 patients. There was no significant difference between the two shunt valves concerning revision rate (p=0.8069), one-year revision rate (p=0.9077), revision free survival (p=0.6921) and overall survival (p=0.3232). Furthermore, regarding one-year revision rate, we observed no significant difference between the two shunt valves in pediatric patients (40.7% vs 27.6%; p=0.2247). Revision operation had to be performed more frequently in pediatric patients (46.6% vs 24.8%; p=0.0093) with a significant higher number of total revisions with proGAV than proGAV 2.0 (55.9% vs. 27.6%; p=0.0110) most likely due to longer follow up in the proGAV -group.
Conclusion: According to the target variables we analyzed, aside from lifetime revision rate in pediatric patients there is no significant difference between the two shunt valves. From our subjective point of view, implantation of the newer proGAV 2.0 valve is preferable due to higher adjustment comfort for both patients and physicians.
Nosocomial infectious diseases (e.g. influenza, pertussis) are a threat particularly for immunocompromised and vulnerable patients. Although vaccination of healthcare workers (HCWs) constitutes the most convenient and effective means to prevent nosocomial transmissions, vaccine uptake among HCWs remains unacceptably low. Worldwide, numerous studies have demonstrated that nurses have lower vaccination rates than physicians and that there is a relationship between receipt of vaccination by HCWs and knowledge. Measures to improve vaccination rates need to be profession-sensitive as well as specific in their approach in order to achieve sustained success.
Health-care personnel (HCP) are exposed to infectious diseases throughout the course of their work. The concerns of pregnant HCP are considerable because certain otherwise mild infections may affect fetal development. We studied 424 pregnant HCP at the University Hospital Frankfurt / Germany between March 2007 and July 2011. Serological tests were carried out for varicella zoster virus (VZV), measles, mumps, rubella (MMR), cytomegalovirus (CMV) and parvovirus B19. Our overall seroprevalence data with regard to VZV, MMR, CMV and parvovirus B 19 corresponded to the general population. It was striking that, only 57.1% of the study population was immune against the four vaccine-preventable diseases (MMR, VZV). Our study suggests that a comprehensive approach to improving the vaccination status of said HCP before pregnancy is paramount.
Previous study showed that kaffir lime leaf contains alkaloid, flavonoid, terpenoid, tannin and saponin. The objective of this study was to examine the cytotoxic effect of kaffir lime leaf extract on cervical cancer and neuroblastoma cell lines. The method used for this research to determine cell viability was an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results showed that an ethyl acetate extract had an IC50 for HeLa cells, UKF-NB3, IMR-5 and SK-N-AS parental cells of 40.7 μg · mL–1, 28.4 μg · mL–1, 14.1 μg · mL–1, and 25.2 μg · mL–1 respectively. Furthermore, the IC50 of chloroform extracts for HeLa cells, UKF-NB3, IMR-5 and SK-N-AS parental were 17.6 μg · mL–1, 18.9 μg · mL–1, 6.4 μg · mL–1, and 9.4 μg · mL–1 respectively. These data showed that kaffir lime extract reduces the viability of cervical and neuroblastoma cell lines and may have potential as anti-cancer compounds.
ecently, pertussis has become a problem also in the adult population, with incidences even higher than in children. Pediatric health care workers (HCWs) are an important source of transmission, exposing very young and immunocompromised patients to an increased risk of potentially severe pertussis infections. Encouraging HCWs to get vaccinated can play a vital role in stopping the transmission of pertussis, thereby reducing institutional outbreaks.
In Germany, HCWs come up with all sorts of reasons for not getting pertussis vaccination. This study was meant to provide information in order to better understand the backgrounds of these attitudes.
A survey was conducted at the children's university hospital in Frankfurt, using an anonymous questionnaire. Survey results were used to design an intervention to increase the immunization rate of staff. Disappointingly, our efforts to increase the acceptance of the immunization program by providing information in advance were not yet satisfying.
Misconception about pertussis vaccination was prevalent especially among nursing staff. The main reasons for non-compliance included: unawareness of an own risk of infection, the belief that pertussis is not a serious illness, fear of side effects, the belief that the pertussis vaccine might trigger the pertussis disease itself, and skepticism about the efficacy of the pertussis vaccination.
Recently, pertussis has become a problem also in the adult population, with incidences even higher than in children. Pediatric health care workers (HCWs) are an important source of transmission, exposing very young and immunocompromised patients to an increased risk of potentially severe pertussis infections. Encouraging HCWs to get vaccinated can play a vital role in stopping the transmission of pertussis, thereby reducing institutional outbreaks.
In Germany, HCWs come up with all sorts of reasons for not getting pertussis vaccination. This study was meant to provide information in order to better understand the backgrounds of these attitudes.
A survey was conducted at the children's university hospital in Frankfurt, using an anonymous questionnaire. Survey results were used to design an intervention to increase the immunization rate of staff. Disappointingly, our efforts to increase the acceptance of the immunization program by providing information in advance were not yet satisfying.
Misconception about pertussis vaccination was prevalent especially among nursing staff. The main reasons for non-compliance included: unawareness of an own risk of infection, the belief that pertussis is not a serious illness, fear of side effects, the belief that the pertussis vaccine might trigger the pertussis disease itself, and skepticism about the efficacy of the pertussis vaccination.
With respect to nosocomial influenza infections, the welfare of patients is best served by high rates of staff immunity against influenza. However, data from the Centers of Disease Control (CDC) in the USA and the Robert Koch-Institute (RKI) in Germany indicate that most of health care workers (HCWs) choose not to be vaccinated. Under voluntary influenza immunization standards, institutional influenza outbreaks occur every flu season. The question about the legality of implementation mandatory flu vaccination for HCWs is an ongoing debate, which covers several different positions.
To characterize the attitudes of German HCWs toward mandatory influenza immunization, an anonymous questionnaire was offered to HCWs of the University Hospital in Frankfurt/Main / Germany. Our study showed that almost 70% of the respondents would accept mandatory influenza vaccination.
In our opinion an annual influenza vaccination should be required for HCWs who care for immunocompromised patients and residents in long-term care if there will be a failure of voluntary vaccination programs. An informed declination should be obtained from employees who decline vaccination and these HCWs ought to work in uncritical areas of patient care.
Medizinstudium, Examina und die Berufstätigkeit sind stressig; belastbare Daten zum allgemeinen und spezifischen Stress während des Medizinstudiums liegen nur in geringem Ausmaß vor. Wir haben die Stressbelastung und Resilienz der Frankfurter Medizinstudenten in den Kohorten 1. vorklinisches Semester, 1. klinisches Semester und PJ-Eintritt erhoben (Trierer Inventar zum chronischen Stress TICS, altersnormierter Mittelwert = 50; Resilienz-Skala RS11, kein Optimum, hohe Werte weisen auf Resilienz hin); an der Studie nahmen jeweils mehr als 90% der entsprechenden Kohorte teil. Während zu Studienbeginn der Summenwert (altersnormierter T-Wert) bei 56% lag, fiel dieser im 1. klin. Semester auf 54%, und stieg zum PJ nur gering wieder an. Unter den Subskalen fiel auf, dass Überlastung, Überforderung und chronische Besorgnis parallel zum Gesamtscore abfielen, die Subskala Unzufriedenheit jedoch zunahm (1. vorklin. Semester 53%, 1. klin. Semester 55%, PJ 58%). Die höchsten Werte in der PJ-Gruppe fanden sich ebenfalls für die Subskalen soziale Überlastung, Mangel an sozialer Anerkennung und Soziale Spannungen. Niedrigere Stressskala-Werte zeigten sich nach dem Staatsexamen M1 in den Subskalen Überlastung, Erfolgsdruck, Überforderung, soziale Isolierung, chronische Besorgnis und dem Summenscore. Überraschenderweise fiel der Summenwert der Resilienz vom 1. vorklinischen und 1. klinischen Semester (80,7%) auf 76,7% vor dem PJ-Eintritt, dieser Abfall zeigte sich für alle 11 Einzelitems dieses Fragebogens in gleicher Weise. Während eine Abnahme der Belastungsabhängigen Skalen Überlastung und Überforderung nach dem Staatsexamen M1 erwartet worden war, überraschte die im Gruppenvergleich abnehmende Resilienz bei den Studenten vor dem Praktischen Jahr. Ebenso überraschend war die fast kontinuierliche Zunahme auf der Subskala Unzufriedenheit während des Studiums. Inwieweit diese Differenzen auf das Studium zurückzuführen sind oder auf eine überzufällige Häufung bei den Studienabbrechern, wird in einer prospektiven Fortführung dieser Studie untersucht.
Die derzeitige Regelung der Zulassung zum Medizinstudium berücksichtigt die Abiturnote und Wartezeiten; universitäre Parameter können diese Kriterien modifizieren. Hierzu zählen z.B. die Leistungskurswahl, wie es an der Goethe-Universität Frankfurt gehandhabt wird. Im Rahmen der Untersuchung zu Stress und Resilienz bei Medizinstudenten haben wir bei den Studenten des 1. vorklinischen Semesters soziodemographische Daten erhoben, die einen Kohortenvergleich erlauben. Die chronische Stressbelastung wurde mit dem Trierer Inventar zum chronischen Stress TICS erhoben (T-Wert von 50 entspricht dem altersnormierten Durchschnitt), die Resilienz mit der Skala RS11 (keine Normwerte, hohe Werte weisen auf Resilienz hin); an der Studie nahmen 90% der Studienanfänger teil. Neben dem Summenscore für Stress wurden die 9 Subskalen Überlastung, Überforderung, Unzufriedenheit, Erfolgsdruck, Soziale Überlastung, soziale Spannungen, Soziale Isolierung, Mangelnde Soziale Anerkennung und Chronische Besorgnis erhoben. Signifikant höhere Werte bei Studentinnen (n=234) als bei Studenten (n=111) fanden sich für die Skalen Überlastung, Überforderung und chronische Besorgnis, mit dem größten Unterschied bei chronischer Besorgnis (♀ T-Wert von 56 der Altersnorm, ♂ 51). Bei älteren Studienanfängern (n=89, Alter >21 Jahre) fand sich eine leichte Korrelation mit den Skalen Soziale Überlastung und Mangel an sozialer Anerkennung; auch im Gruppenvergleich haben ältere Studenten mit einem T-Wert von 55 einen signifikant höheren Wert als junge Studenten (T-Wert 50). Auch die Notwendigkeit, das Studium ganz (n=86) oder teilweise (n=58) selbst zu finanzieren, erhöht die Werte auf den Skalen Soziale Überlastung, Soziale Spannung, Mangel an sozialer Anerkennung sowie den Summenscore. Keinen Einfluss hatten Parameter wie „nichtdeutsche Hochschulzugangsberechtigung“, dagegen finden sich bei Studenten mit einer nicht-deutschen Muttersprache (n=61) und Sprachschwierigkeiten (n=12) häufiger überfordert, überlastet, sozial nicht anerkannt, chronisch besorgt und gestresst. Ein erhöhter Stress bei Medizin-Anfängern wird bei Frauen, älteren Studienanfängern sowie eigener Finanzierung gesehen. Überraschend war der geringe Einfluss von Parametern wie Deutsch als Fremdsprache, oder kulturelle Faktoren, die über einen oder beide Elternteile außerhalb Deutschlands oder der EU erfasst wurden.
Aims: We have provided evidence in former studies that cytokines (IL-8, TNF alpha, LBP, TGFß) measured in blood correlate negatively with lung function in deltaF508 homozygous patients. GAP junction proteins might be of importance for the influx of blood cells into the lung. Our aim was to assess the relationship between connexin genotypes and cytokines (IL-8, TNF-alpha, LBP, TGFß) in induced sputum and serum, and lung disease.
Methods: 36 patients homozygous for deltaF508 (median age 18 y, m/f 16/20, FEV1(%) 77) were examined. Sequence analysis was performed for genes encoding GAP junction protein alpha 1 (GJA1/connexin 43) and gap junction protein alpha 4 (GJA4/connexin 37). Cytokines were assessed in serum and induced sputum (IS) by chemiluminescence (DPC Biermann, Bad Homburg, Germany) as well as leukocyte counts.
Results: DNA analysis was performed in 35 patients. Whereas GJA1 showed only one rare heterozygous synonymous SNP (rs138386744) in one patient, four common SNPs were detected in GJA4. Two were synonymous changes, but the third variant (rs41266431) predicts an amino acid substitution (GTA → valine, ATA → isoleucine) as well as the fourth SNP (rs1764391: CCC→proline, TCC→serine). For rs41266431 patients with homozygosity for the G variant had higher IL-8 levels (median: 13.3/8.0 pg/ml, p=0.07) in serum as well as leukocytes in sputum (median: 2050/421 /µl p=0.041) than those showing heterozygosity (G/A). In individuals > 30 years lung function (FEV1 41.3/84.83 % predicted, p=0.07) was worse.
Conclusion: SNP rs41266431 seems a promising candidate for further investigations, suggesting GJA4 a potential disease modifying gene.
Modeling the effects of neuronal morphology on dendritic chloride diffusion and GABAergic inhibition
(2014)
Poster presentation at the Twenty Third Annual Computational Neuroscience Meeting: CNS*2014 Québec City, Canada. 26-31 July 2014.
Gamma-aminobutyric acid receptors (GABAARs) are ligand-gated chloride (Cl−) channels which mediate the majority of inhibitory neurotransmission in the CNS. Spatiotemporal changes of intracellular Cl− concentration alter the concentration gradient for Cl− across the neuronal membrane and thus affect the current flow through GABAARs and the efficacy of GABAergic inhibition. However, the impact of complex neuronal morphology on Cl− diffusion and the redistribution of intracellular Cl− is not well understood. Recently, computational models for Cl− diffusion and GABAAR-mediated inhibition in realistic neuronal morphologies became available [1-3]. Here we have used computational models of morphologically complex dendrites to test the effects of spines on Cl− diffusion. In all dendritic morphologies tested, spines slowed down longitudinal Cl− diffusion along dendrites and decreased the amount and spatial spread of synaptically evoked Cl− changes. Spine densities of 2-10 spines/µm decreased the longitudinal diffusion coefficient of Cl− to 80-30% of its value in smooth dendrites, respectively. These results suggest that spines are able to limit short-term ionic plasticity [4] at dendritic GABAergic synapses.
Poster presentation: 28th Annual Scientific Meeting of the Society for Immunotherapy of Cancer (SITC)
Significant progress has been made over the last decade towards realizing the potential of natural killer (NK) cells for cancer immunotherapy. NK cells can respond rapidly to transformed and stressed cells, and have the intrinsic potential to extravasate and reach their targets in almost all body tissues. In addition to donor-derived primary NK cells, also continuously expanding cytotoxic cell lines such as NK-92 are being considered for adoptive cancer immunotherapy. High cytotoxicity of NK-92 has previously been shown against malignant cells of hematologic origin in preclinical studies, and general safety of infusion of NK-92 cells has been established in phase I clinical trials. To enhance their therapeutic utility, we genetically modified NK-92 cells to express chimeric antigen receptors (CAR) specific for tumor-associated surface antigens. Such CAR were composed of a tumor-specific scFv antibody fragment fused via hinge and transmembrane domains to intracellular signaling moieties such as CD3 zeta chain, or composite fusion molecules also containing a costimulatory protein domain in addition to CD3 zeta. For development towards clinical applications, here a codon-optimized second generation CAR was constructed that consists of an ErbB2-specific scFv antibody domain fused via a linker to a composite CD28-CD3 zeta signaling domain. GMP-compliant protocols for vector production, lentiviral transduction and expansion of a genetically modified NK-92 single cell clone (NK-92/5.28.z) were established. Functional analysis of NK-92/5.28.z cells revealed high and stable CAR expression, selective cytotoxicity against ErbB2-expressing but otherwise NK-resistant tumor cells of different origins in vitro, as well as homing to ErbB2-expressing tumors in vivo. Furthermore, antigen specificity and selective cytotoxicity of these cells were retained in vivo, resulting in antitumoral activity against subcutaneous and intracranial glioblastoma xenografts in NSG mice. Ongoing work now focuses on the development of these cells for adoptive immunotherapy of ErbB2-positive glioblastoma.
Das Medizinstudium und die spätere Berufstätigkeit werden als stressig angesehen; dennoch liegen nur wenige Daten zur Stressbelastung von Medizinstudenten und Ärzten vor. Als Teil einer umfangreichen Erhebung zur Stressbelastung haben wir die Stressbelastung und Resilienz von Frankfurter Medizinstudenten in den ersten Wochen des 1. vorklinischen Semesters erhoben (Trierer Inventar zum chronischen Stress TICS, Resilienz-Skala RS11); an der Studie nahmen 348 von 383 Studienanfängern (90,8%) teil. Übereinstimmend mit Ergebnissen aus dem 5. Semester zeigen die Studenten des 1. Semesters hohe Werte insbesondere in den Teilskalen Überlastung und Überforderung; auffallend sind ebenfalls hohe Werte in den Skalen Soziale Isolation und Summenscore. Ein T-Score (altersnormierter Normalwert = 50) über der 2fachen Vertrauensgrenze findet sich im Summenscore (17,2%), chronische Besorgnis (17,8%), Überforderung (11,2%) und Überlastung (22,7%), während in anderen Skalen entsprechende Werte nur bei 1–5% der Teilnehmer erreicht wurden. Die Skalen Überlastung, Erfolgsdruck, chronische Besorgnis sowie der Summenscore sind weitgehend normalverteilt (Schiefe <0,2), dieser Wert beträgt für die anderen Skalen 0,45–0,65. Zwischen den Unterskalen finden sich Korrelationskoeffizienten >0,5 für Überlastung und Überforderung sowie chronischer Besorgnis, zwischen Überforderung und mangelnder sozialer Anerkennung, sozialer Isolierung und chronischer Besorgnis sowie zwischen sozialen Spannungen, sozialer Isolierung und chronischer Besorgnis. Parallel wurde die Resilienz mit Hilfe des Fragebogens RS11 erhoben (kein Optimum, hohe Werte weisen auf Resilienz hin). Bei einer Maximalpunktzahl von 77 erreichten die Studenten 62,2 +/– 8,8 Punkte, bei einer ausgeprägten rechtsschiefen Verteilung. Zwischen der Stressbelastung und der Resilienz fand sich keine relevante Korrelation, mit einem Maximalwert von –0,267 zwischen dem RS11-Score und der Subskala Überforderung. Die Daten belegen ein bereits zu Studienbeginn vorliegendes hohes Maß an Überlastung und Überforderung; dieser Stress korreliert nicht mit der Fähigkeit, mit Stress adäquat umzugehen (Resilienz).
Oral presentation: 23rd World Congress of the World Society of Cardio-Thoracic Surgeons. Split, Croatia. 12-15 September 2013.
Background: In the past, questions have been raised, whether an open flexible annuloplasty band can reliably prevent recurrent mitral valve regurgitation. The purpose of this study was to evaluate the durability of mitral valve repair at midterm, using the Cosgrove-Edwards annuloplasty band in a homogenic patient cohort.
Methods: From January 2004 to December 2007, 157 consecutive patients with degenerative mitral valve disease were included in the study. All had quadrangular resection of a P2 prolapse and annuloplasty with a Cosgrove-Edwards annuloplasty band. Clinical and echocardiography follow-up was complete.
Results: There was no intraoperative or 30 day mortality. After a mean follow-up of 5.0 ± 1.9 years, survival was 94.3%. At midterm, freedom from reoperations was 98.9%, freedom from thromboembolism was 97.5% and freedom from endocarditis was 99.4%. Echocardiography follow-up showed recurrent mitral valve regurgitation higher than grade 2 in two patients. Mean ejection fraction was 60.3 ± 10.2%, left atrial diameter was 42 ± 7 mm, mean gradient was 3.2 ± 1.4 mmHg, effective orifice area was 3.3 ± 1.3cm², mitral leaflet coaptation length was 7.5 ± 1.9 mm and mitral leaflet tethering height was 6.2 ± 2.3 mm.
Conclusion: Mitral valve repair using the Cosgrove annuloplasty band for degenerative mitral valve disease provides an effective and durable form of reconstruction.
Oral presentation: 23rd World Congress of the World Society of Cardio-Thoracic Surgeons. Split, Croatia. 12-15 September 2013.
Background: Partial upper sternotomy (PUS) is established less invasive approach for single and double valve surgery. Reports of aortic surgery performed through PUS are rare.
Methods: The records of 52 patients undergoing primary elective surgery on the proximal aorta through PUS between 2005 and 2011 were reviewed. Patients mean age was 57 years, 35% were in NYHA Class III or IV, 59% had recent cardiac decompensation, and 17% had pulmonary hypertension. The PUS was taken down to the 4th left intercostal space in 44 patients (85%).
Results: No conversion to full sternotomy was necessary. The aortic cross-clamp, cardiopulmonary bypass and operative times averaged 136 ± 20 min., 186 ± 36 min. and 327 ± 83 min., respectively. In eight patients, the right axillary artery was cannulated for establishing cardiopulmonary bypass; the others were cannulated centrally. All patients except one received a procedure on the ascending aorta, either replacement in 30 (58%) or reduction aortoplasty in 21 (40%). Aortic root replacement was additionally performed in 31 patients (60%), including David in 20 (38%) and Ross procedure in 6 (11.5%). The aortic arch was replaced either partially in 5 (10%) or totally in 3 (6%) patients, in moderate hypothermia employing antegrade cerebral perfusion. Additional procedures, included mitral valve repair in 15 (29%) patients and coronary grafting. Ventilation time, intensive care unit and hospital stay averaged 17 ± 12 hours, 2 ± 1, and 11 ± 9 days. Chest drainage was 470 ± 380 ml/24 hours. Permanent neurologic deficit did not occur. Wound dehiscence was observed in a single patient (2%). Thirty-day and hospital mortality were not observed.
Conclusions: Less invasive surgery on the aortic root, ascending aorta and aortic arch can be performed safely and reproducibly. Potential benefits include a minimized risk of wound dehiscence and reduced postoperative bleeding. The PUS does not compromise the quality of the operation.
Cytoprotective functions of amyloid precursor protein family members in stress signaling and aging
(2013)
Poster presentation: Molecular Neurodegeneration: Basic biology and disease pathways Cannes, France. 10-12 September 2013.
Background: The amyloid precursor protein (APP) is processed via two different metabolic pathways: the amyloidogenic and the non-amyloidogenic pathway, the latter of which leading to generation of the secreted N-terminal APP fragment sAPPα [1]. Previous studies from our group suggest that sAPPα exerts potent neuroprotective effects and inhibits stress-triggered cell death via modulation of gene expression, as well as by antagonizing different types of neurotoxic stress [2]. It was also observed that the biochemical processing of APP is downregulated during aging which in turn reduced the secretion of sAPPα [3]. Based on these observations, we have studied the potential physiological function of sAPPα/APP and APLPs (APP like proteins) on the regulation of age-associated, stress induced signaling pathways, apoptosis and senescence.
Materials and methods: SH-SY5Y, PC12, IMR90 cells were used as cellular models. Depletion of APP, APLP1 (APP like protein 1) and APLP2 (APP like protein 2) in SH-SY5Y cells was achieved by stable lentiviral knockdown. To analyze the protective function of sAPPα, we have used conditioned supernatants of wild type APP overexpressing HEK cells and recombinant His-tagged sAPPα purified from yeast. The cells were treated with sAPPα prior to the addition of different stress stimuli (MG132, epoxomicin, UV, H2O2) after which cell death, gene expression and senescence were analyzed by MTT assays, caspase activity assays, Western blots and X-Gal staining respectively.
Results: Our data show that sAPPα can antagonize premature senescence induced by repetitive short term induction of proteasomal stress in IMR-90 cells and apoptosis triggered by prolonged proteasomal stress and other death stimuli in PC12, SH-SY5Y and IMR90 cells which was accompanied by a sAPPα-dependent inhibition of the JNK stress signaling pathway. In contrast, no significant changes in cell viability and apoptosis were observed when APP knockdown cells were pretreated with sAPPα.
Conclusions: Our observations suggest that sAPPα can antagonize both apoptosis and cellular senescence and requires expression of holo-APP to mediate its cytoprotective effects. They also support the notion that the physiological function of APP is linked to modulation of neuronal and brain aging.
Network or graph theory has become a popular tool to represent and analyze large-scale interaction patterns in the brain. To derive a functional network representation from experimentally recorded neural time series one has to identify the structure of the interactions between these time series. In neuroscience, this is often done by pairwise bivariate analysis because a fully multivariate treatment is typically not possible due to limited data and excessive computational cost. Furthermore, a true multivariate analysis would consist of the analysis of the combined effects, including information theoretic synergies and redundancies, of all possible subsets of network components. Since the number of these subsets is the power set of the network components, this leads to a combinatorial explosion (i.e. a problem that is computationally intractable). In contrast, a pairwise bivariate analysis of interactions is typically feasible but introduces the possibility of false detection of spurious interactions between network components, especially due to cascade and common drive effects. These spurious connections in a network representation may introduce a bias to subsequently computed graph theoretical measures (e.g. clustering coefficient or centrality) as these measures depend on the reliability of the graph representation from which they are computed. Strictly speaking, graph theoretical measures are meaningful only if the underlying graph structure can be guaranteed to consist of one type of connections only, i.e. connections in the graph are guaranteed to be non-spurious. ...
When studying real world complex networks, one rarely has full access to all their components. As an example, the central nervous system of the human consists of 1011 neurons which are each connected to thousands of other neurons. Of these 100 billion neurons, at most a few hundred can be recorded in parallel. Thus observations are hampered by immense subsampling. While subsampling does not affect the observables of single neuron activity, it can heavily distort observables which characterize interactions between pairs or groups of neurons. Without a precise understanding how subsampling affects these observables, inference on neural network dynamics from subsampled neural data remains limited.
We systematically studied subsampling effects in three self-organized critical (SOC) models, since this class of models can reproduce the spatio-temporal activity of spontaneous activity observed in vivo. The models differed in their topology and in their precise interaction rules. The first model consisted of locally connected integrate- and fire units, thereby resembling cortical activity propagation mechanisms. The second model had the same interaction rules but random connectivity. The third model had local connectivity but different activity propagation rules. As a measure of network dynamics, we characterized the spatio-temporal waves of activity, called avalanches. Avalanches are characteristic for SOC models and neural tissue. Avalanche measures A (e.g. size, duration, shape) were calculated for the fully sampled and the subsampled models. To mimic subsampling in the models, we considered the activity of a subset of units only, discarding the activity of all the other units.
Under subsampling the avalanche measures A depended on three main factors: First, A depended on the interaction rules of the model and its topology, thus each model showed its own characteristic subsampling effects on A. Second, A depended on the number of sampled sites n. With small and intermediate n, the true A¬ could not be recovered in any of the models. Third, A depended on the distance d between sampled sites. With small d, A was overestimated, while with large d, A was underestimated.
Since under subsampling, the observables depended on the model's topology and interaction mechanisms, we propose that systematic subsampling can be exploited to compare models with neural data: When changing the number and the distance between electrodes in neural tissue and sampled units in a model analogously, the observables in a correct model should behave the same as in the neural tissue. Thereby, incorrect models can easily be discarded. Thus, systematic subsampling offers a promising and unique approach to model selection, even if brain activity was far from being fully sampled.
Neuronal dynamics differs between wakefulness and sleep stages, so does the cognitive state. In contrast, a single attractor state, called self-organized critical (SOC), has been proposed to govern human brain dynamics for its optimal information coding and processing capabilities. Here we address two open questions: First, does the human brain always operate in this computationally optimal state, even during deep sleep? Second, previous evidence for SOC was based on activity within single brain areas, however, the interaction between brain areas may be organized differently. Here we asked whether the interaction between brain areas is SOC. ...
Meeting Abstract : 82. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie. Freiburg i. Br., 01.-05.06.2011.
Ca. 3 Millionen Erwachsene in der Bundesrepublik Deutschland leiden unter Tinnitus, wobei eine bei jedem dieser Patienten zur Heilung führende Therapie bisher noch nicht existiert. Ansatzpunkt einer neuartigen Therapie ist die Wiederherstellung des normalen elektrischen Entladungsmusters im Hörnerv mittels elektrischer Stimulation. Hiermit berichten wir über unsere ersten Erfahrungen mit dem Tinnelec, einem Implantat mit einer einzelnen Stimulations-Elektrode die in der Rundfensternische platziert wird.
Zurzeit haben wir 4 einseitig ertaubten Patienten mit Tinnitus auf dem betroffenen Ohr jeweils ein Tinnelec-System implantiert. Die Dauer des Tinnitus betrug mindestens ein Jahr und gängige Tinnitus-Therapien wie z.B. Infusionstherapie waren erfolglos geblieben. Ein psychogener Tinnitus wurde ausgeschlossen. Der durch den Tinnitus verursachte Leidensdruck wurde anhand einer VAS Scala (Visuelle Analog Scala) und eines Tinnitus-Handicap-Inventory (THI) Fragebogens beurteilt. Die Reizapplikation betrug mind. 4 Stunden täglich. Als Stimulationsparameter wurde eine Reizmusterannäherung an den Tinnitus angestrebt.
Bei drei Patienten wurde unter der Stimulation der Tinnitus erträglicher, eine zeitweise komplette Unterdrückung des Tinnitus schon innerhalb der ersten Therapie-Wochen wurde jedoch nur in einem der Fälle berichtet. Diese Ergebnisse wurden auch durch das THI und VAS unterstützt.
Die Tinnelec-Implantation erscheint für Tinnitus Erfolg versprechend zu sein. Weitere Studien bei Tinnitus-Patienten ohne zusätzliche Hörbeeinträchtigung sind jedoch notwendig bis endgültige Schlussfolgerungen betreffend dieses Implantats gezogen werden können. In jedem Fall bleibt die Option einer Cochlea-Implantation im selben Ohr, nach Explantation des Tinnelec, bestehen.
Meeting Abstract : Gesellschaft für Arzneimittelanwendungsforschung und Arzneimittelepidemiologie e.V. (GAA). 17. Jahrestagung der Gesellschaft für Arzneimittelanwendungsforschung und Arzneimittelepidemiologie. Osnabrück, 25.-26.11.2010.
ntroduction: Several drugs require dose adjustment in patients with impaired renal function, which however, often goes undetected. Serum creatinine may be normal in patients while renal function is already reduced. The estimated GFR (eGFR) allows a more precise evaluation of the renal function. This study was carried out in a group practice for family medicine, in Frankfurt/ Main, Germany. The exploration aimed at investigating if patients with renal insufficiency were recognised and if their prescriptions were appropriate in terms of dose adjustment or contra-indications.
Methods: In patients (>65yrs) with renal insufficiency (creatinine clearance <60 ml/min), their prescribed medication was retrospectively explored (Observation period 1.1.2008 to 1.4.2009). The Cockroft-Gault formula was used as estimate for the eGFR, using a creatinine value from the patient’s charts. In 90 patients, a second eGFR could be estimated from a second creatinine value obtained within 3-6 months. The recommended dose of each prescription in the SmPC (Fachinformation“) was compared to the dose that had been actually prescribed.
Results: Out of 232 consecutively patients >65 yrs, 102 had an eGFR <60 ml/min, 16 of these had an eGFR <30 ml/min. The eGFR was closely correlated (r2=0.81) with an independent second eGFR. Out of these 102 patients, 48 had a serum creatinine level within the normal range. Renal adjustment was required in 263 of a total of 613 prescriptions. 72 prescriptions in a total of 45 patients were not appropriately adjusted (32) or prescribed despite a contraindication (40). For chronic prescriptions, metformin, ramipril, enalapril, HCTZ, and spironolactone accounted for 70% of inappropriate dosing; the magnitude of misdosing was 1.5 to 4 fold (median 2). 9 temporary prescriptions (of a total of 60 prescriptions) in 8 patients were not adjusted (cefuroxim, cefpodoxim, levofloxacin). We could not prove that patients with normal serum creatinine had a higher rate of inappropriate dosing than those with already elevated creatinine.
Discussion and conclusion: In this GP practice, we have demonstrated a considerable prevalence of inappropriate dosing in patients with impaired renal function. It remains to be elucidated whether surveillance of appropriate dosing in renal impairment can be optimized e.g. with CPOE.
Einleitung: Für die meisten Patienten mit HCC ist die LTX die einzige kurative Behandlungsoption. Bei diesen Patienten scheint eine Kontrolle der Erkrankung durch lokale Verfahren im Intervall bis zur LTX zu erreichen zu sein. Als das beste Verfahren gilt die transarterielle Chemoembolisation (TACE). Die Effektivität ist jedoch umstritten. Möglicherweise kann sie aber Patienten startifizieren, die ein hohes Rezidivrisiko haben.
Material und Methoden: Im Zeitraum zwischen 1995 und 2005 wurden n=27 Patienten mit HCC im Alter zwischen 22 und 69 Jahren transplantiert. Hiervon erhielten n=15 Patienten eine Vorbehandlung in Form einer alleinigen TACE oder kombiniert mit PEI [n=1] bzw. LITT [n=1]. Retrospektiv wurde das Gesamtüberleben sowie das „Event-free-survival“ (Rezidiv, Reinfektion und Tod) analysiert.
Ergebnisse: Die mittlere Wartezeit betrug bei Patienten in der TACE-Gruppe 214 Tage, bei Patienten ohne Vorbehandlung 133 Tage. Bei einem mittleren Nachbeobachtungszeitraum von 1097 ± 1193 Tagen für TACE-Patienten und 1674 ± 966 Tagen für non-TACE-Patienten betrug das Überleben für Patienten, die mit TACE vorbehandelt wurden 83,3%, für Patienten, die keine TACE erhielten 86.7% (p=0,5693). Gleiches fand sich für das Event-free-survival (p=0,8823). Das Gesamtüberleben der Patienten, die auf der Warteliste einen Tumorprogress hatten lag bei 77%, während Patienten mit stabiler Tumorgröße oder Regredienz der Tumore ein Überleben von 93% aufwiesen (p=0,0153). Unter TACE-Behandlung zeigten 5/15 Patienten eine zunehmende Anzahl an Herden im histologischen Präparat verglichen mit der Ausgangsbildgebung. Nur bei einem Patienten zeigte sich der Progress der Erkrankung bereits in der präoperativen Bildgebung. Patienten mit einem Progress der Erkrankung hatten ein Gesamtüberleben von 60%, während Patienten mit „stable disease“ oder Rückgang der Herde ein Gesamtüberleben von 100% hatten (p=0,0180).
Schlussfolgerung: Unseren Ergebnisse zufolge ist der Effekt der TACE als Bridgingverfahren auf das Überleben der Patienten fraglich. Allerdings scheint die TACE zur Riskostratifizierung geeignet zu sein. In unserem Patientenkollektiv hatten Patienten, die eine Progredienz der Erkrankung auf der Warteliste zeigten ein signifikant schlechteres Gesamtüberleben. Dies gilt auch bei ausschließlicher Betrachtung der Patienten mit TACE.
Meeting Abstract : 10. Deutscher Kongress für Versorgungsforschung, 18. GAA-Jahrestagung. Deutsches Netzwerk Versorgungsforschung e. V. ; Gesellschaft für Arzneimittelanwendungsforschung und Arzneimittelepidemiologie e. V. 20.-22.10.2011, Köln
Hintergrund: Multimedikation als Folge von Multimorbidität ist ein zentrales Problem der Hausarztpraxis und erhöht das Risiko für unangemessene Arzneimittel-Verordnungen (VO). Um die Medikation bei älteren, multimorbiden Patienten zu optimieren und zu priorisieren, wurde eine computergestützte, durch Medizinische Fachangestellte (MFA) assistierte, komplexe Intervention (checklistengestütztes Vorbereitungsgespräch sowie Überprüfung eingenommener Medikamente durch MFA, Einsatz des web-basierten ArzneimittelinformationsDienstes AiD, spezifisches Arzt-Patienten-Gespräch) entwickelt und in einer 12-monatigen Pilotstudie auf Machbarkeit getestet. Ein auf 9 Items reduzierter MAI [1] wurde eingesetzt, um dessen Eignung als potentielles primäres Outcome der Hauptstudie zu prüfen.
Material und Methoden: In die Pilotstudie in 20 Hausarztpraxen mit Cluster-Randomisation auf Praxisebene in Kontrollgruppe (Regelversorgung b. empfohlenem Standard) vs. Interventionsgruppe (komplexe Intervention b. empfohlenem Standard) wurden 5 Pat./Praxis eingeschlossen (≥65 Jahre, ≥3 chron. Erkrankungen, ≥5 Dauermedikamente, MMSE ≥26, Lebenserwartung ≥6 Monate). Zur Bewertung des MAI wurden an Baseline (T0), 6 Wo. (T1) & 3 Mon. (T2) nach Intervention erhoben: VO, Diagnosen, Natrium, Kalium & Kreatinin i.S., Größe, Gewicht, Geschlecht, Cumulative Illness Rating Scale (CIRS) [2] durch die Hausarztpraxis; Symptome für unerwünschte Arzneimittelwirkungen im Patienten-Telefoninterview.
Für den MAI wurde die Angemessenheit jeder VO in den 9 Kategorien Indikation, Effektivität, Dosierung, korrekter & praktikabler Applikationsweg, Arzneimittelwechselwirkung, Drug-disease-Interaktion, Doppelverordnung, Anwendungsdauer 3-stufig bewertet (1 = korrekt - 3 = unkorrekt) und für die Auswertung auf Patientenebene summiert. Die Bewertung erfolgte ohne Kenntnis der Gruppenzugehörigkeit. Deskriptive Statistiken und Reliabilitätsanalysen, ungewichtete Auswertung und Gewichtung n. Bregnhoj [3].
Ergebnisse: Es wurden N=100 Patienten in die Studie eingeschlossen, im Mittel 76 Jahre (Standardabweichung, SD 6; Range, R: 64-93) , 52% Frauen, durchschnittlich 9 VO/Pat. (SD 2; R 4-16), mittlerer CIRS-Score 10 (SD 4; R 0-23). Basierend auf N=851 VO (100 Pat.) zu T0 betrug der Reliabilitätskoeffizient (RK, Cronbachs Alpha) der ungewichteten 9 Items 0,70. Items 1-5 wiesen akzeptable Trennschärfen auf (0,52-0,64), die der Items 6, 7 & 9 fielen mit 0,21-0,29 niedriger aus, die des Item 8 betrug 0,06. Auf der Basis der 9 gewichteten Items fiel die interne Konsistenz des MAI erwartet höher aus (0,75). Die Reliabilitätsanalysen auf VO-Ebene zeigten einen RK von 0,67 (ungewichtet) vs. 0,75 (gewichtet), die Trennschärfen waren vergleichbar. Zur Zwischenauswertung betrug der MAI (T1-T0) in der Interventionsgruppe (5 Praxen, 24 Pat.) -0,9 (SD 5,6), in der Kontrollgruppe (7 Praxen, 35 Pat.) -0,5 (SD 4,9); die Differenz zwischen beiden Gruppen Mi–Mk -0,4 [95% Konfidenzintervall: -3,4;2,6].
Schlussfolgerung: Der MAI ist als potentielles primäres Outcome in der Hauptstudie geeignet: wenige fehlende Werte, Darstellung von Unterschieden prä-post und zwischen den Gruppen, akzeptable interne Konsistenz. Der niedrige Trennschärfekoeffizient des Items 8 weist darauf hin, dass dieses Item nicht mit dem Gesamt-Skalenwert korreliert, auch die Items 6, 7 und 9 korrelieren wesentlich schwächer mit dem Gesamt-Skalenwert als die Items 1 bis 5. Eine Wichtung z.B. der Items 2, 5, 6 und 9 könnte erwogen werden, um den Fokus der Intervention in der Hauptzielgröße angemessen abzubilden.
Meeting abstract : Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2012), 23.10.-26.10.2012, Berlin.
Fragestellung: Die Behandlung langstreckiger Knochendefekte ist eine große Herausforderung. Die Masquelet-Technik zur Behandlung solcher Defekte ist eine zweizeitige Operationstechnik. Zuerst erfolgt die Insertion eines PMMA (Polymethylmethacrylat)-Zementspacers in den Knochendefekt, der die Bildung einer Membran induziert. Diese Membran enthält Wachstumsfaktoren und regenerative Zellen, die möglicherweise die Knochenheilung unterstützen. Nach einigen Wochen wird der Zementspacer entfernt und der induzierte Membranschlauch mit Beckenkammspongiosa aufgefüllt. Im weiteren Verlauf kommt es zu einer kompletten Knochenheilung. Ziele dieser Untersuchung waren die Etablierung der Masquelettechnik am Rattenmodell und die Definition eines Zeitpunkts, an welchem die Membran eine ausreichende Festigkeit sowie einen signifikanten Gehalt von Vorläuferzellen aufweist.
Methodik: Nach Genehmigung der Experimente wurden die Femura von 24 männlichen SD-Ratten osteotomiert. Die Lücke (10 mm) wurde mit PMMA-Zement aufgefüllt und mittels Miniplatte stabilisiert. Parallel wurden den Versuchstieren gleich große PMMA-Spacer subcutan unter die Rückenhaut implantiert. Nach 2, 4, bzw. 6 Wochen (W) erfolgte die Entnahme der Membranen. Ein Teil der Membran wurde für (immun)histologische Untersuchungen aufbereitet (CD34, vWF, van Giesson), ein Teil für die in vitro Kultur. Auswachsende Vorläuferzellen in vitro wurden über CD34 und STRO-1-Färbung nachgewiesen. Statistik: Mediane, Kruskal-Wallis-Test, p<0,05 ist signifikant.
Ergebnisse und Schlussfolgerungen: Im zeitlichen Verlauf nahmen die Vaskularisierung (vWF-positive Fläche [%]: 2 W: 1,8; 4 W:1.6 vs 6 W: 6,4), die Dicke der Membran ([µm]: 2 W: 350 vs 4W: 517, 6 W: 592) und der Bindegewebsanteil ([µm]: 2W: 201 vs 4W: 324, 6W: 404) signifikant zu. Der Hauptanteil elastischer Fasern war auf der dem Zement zugewandten Seite, Vaskularisierung war eher auf der Weichteil zugewandten Seite zu finden. Der Anteil CD34 positiver Zellen nahm signifikant ab (2W: 5%, 4 W: 4% vs 6 W: 1%). Auswachsende STRO-1 positive Zellen konnten nur in zweiwöchigen Membranen nachgewiesen werden. Ältere Membranen wiesen einen zunehmenden Anteil seneszenter Zellen auf. Subcutan induzierte Membranen waren vergleichbar, wiesen jedoch tendentiell eine geringere Dicke und keine STRO-1 positiven Zellen auf.
Mit dieser Studie wurde erstmalig die Induktion einer Membran nach Masquelet im Rattenmodell etabliert. Es konnte nachgewiesen werden, dass der strukturelle Aufbau sowie die zellulären Komponenten zeitlichen Änderungen unterliegen und der Ort der Induktion Einfluss auf die zellulären Komponenten der Membran hat. Junge Membranen (2W) enthielten CD34 und STRO-1 positive Zellen. 4W-Membranen enthielten nur CD34 positive Zellen wiesen aber einen signifikanten Bindegewebsanteil auf, der für eine erhöhte mechanische Stabilität spricht. Ob 2 bzw. 4 Wochen alte Membranen den Knochenheilungsprozess fördern, muss in weiterführenden Studien untersucht werden.
Hintergrund: Die Unterschidung von Augen mit frühem Keratokonus (KC) von normalen Augen bereitet nach wie vor Schwierigkeiten. Die vorliegende Untersuchung vergleicht konventionelle keratometrie-basierte mit wellenfront-basierten Maßzahlen hinsichtlich ihrer Eignung, normale Augen von Augen mit sehr frühem Keratokonus zu unterscheiden.
Methoden: Es wurden 17 Augen von 17 Patienten mit frühem KC eingeschlossen. Bei diesen 17 Augen handelt es sich um klinisch unauffällige Partneraugen des stärker betroffenen Auges. 123 Normalaugen von 69 Patienten dienten als Negativkontrolle. Von den axialen Kurvaturdaten wurden folgende Maßzahlen berechnet: zentrale Keratometrie (cK), Astigmatismus (AST), inferior-superiore Brechwertdifferenz (I-S), Verkippung der radialen Achsen (SRAX), KISA% index (eine Maßzahl, die auf cK, AST, I-S und SRAX basiert) und corneale Zernike-Koeffizienten (1.–7. Ordnung, Pupillendurchmesser: 6 mm). Aus Zernike-Koeffizienten wurden Diskriminanzfunktionen konstruiert. Receiver-Operatiing-Charakteristik (ROC)-Kurven wurden erstellt, um die diagnostische Trennschärfe dieser Werte zur Unterscheidung von klinisch unauffälligen Partneraugen von Augen mit frühem Keratokonus und normalen Kontrollen zu evaluieren.
Ergebnisse: Der I-S-Wert (Korrektheit 92,1%, kritischer Wert 0,59 D) und die vertikale Coma (C3-1; 96,7%, –0,2 µm) waren die beiden Einzelwerte mit höchster Trennschärfe. Mit den ursprünglich publizierten kritischen Werten lag der Rabinowitz-McDonnell test (cK und I-S) bei 83,3% (Sensitivität 0%, Spezifität 100%) und der KISA% bei 70,8% (81,3%, 60,3%). In Verbindung mit Diskriminanzanalyse errichten Zernike-Koeffizienten eine Korrektheit von 96,7% (100%, 93,4%).
Schlussfolgerungen: Auf cornealen Zernike-Koeffizienten basierende Maßzahlen erreichte die höchste Trennschärfe bei der Unterscheidung von Augen mit subklinischem KC von Normalaugen. Dennoch konnten konventionelle KC-indices eine ähnlich hohe Trenschärfe wie die Zernike-Methode erreichen, wenn die kritischen Werte entsprechend angepasst werden.
Fragestellung: Beurteilung der Korrektur des Astigmatismus mit der multifokalen torischen Intraokularlinsen (IOL) ReSTOR Toric (Alcon, Ft. Worth, USA) bei Kataraktoperation.
Methodik: Die Multicenterstudie umfasste Kataraktepatienten mit präoperativem Astigmatismus von ≥0,75 bis ≤2,5 dpt. die Patienten wurden einer bilateralen Implantation einer torischen multifokalen IOL zur Korrektur der Hornhautverkrümmung unterzogen. Die OP erfolgte ohne relaxierende limbale Inzisionen durch eine clear-cornea Inzision <3,0 mm. Prä- und postoperativ wurden für diese Subanalyse Autokeratometrie sowie subjektiver Astigmatismus von 39 Augen von 40 Patienten im Alter von 59,8±7,0 Jahren analysiert.
Ergebnisse: Präoperativ betrug der mittlere keratometrische Astigmatismus 1,43±0,57 dpt. Die mittlere Inzisionsgröße betrug 2,59±0,41 mm. 1 Monat postoperativ betrug der mittlere keratometrische Astigmatismus 1,51±0,95 dpt (25 Augen). Der Unterschied im keratometrischen Astigmatismus zwischen präoperativ und 1-Monat-postop betrug 0,57±0,96 dpt. Der präoperative subjektive Astigmatismus wurde signifikant von 0,32±0,33 dpt (25 Augen) auf 0,99±0,70 dpt reduziert. (39 Augen, p <0,0001).
Schlussfolgerung: Die Implantation der multifokale torischen IOL zeigt vorhersehbare postoperative Ergebnisse bei der Korrektur des Astigmatismus nach kataraktoperation.
Hintergrund: Im Rahmen der Erforschung von Mechanismen der Presbyopie-Entstehung hat das Interesse an Methoden zur Linsendensitometrie wieder zugenommen. Für spezielle Fragestellungen sind flexible Untersuchungsmethoden notwendig.
Methoden: Basierend auf Aufnahmen mit der Scheimpflug-Kamera Pentacam HR (Oculus, Wetzlar) wurde ein MATLAB-Programm (V7.0, The MathWorks) erstellt, um größere Datenmengen automatisiert auszuwerten. Die Erkennung der Pupillenmitte als Referenzpunkt erfolgt mittels eines Randerkennungsalgorithmus. Als Kennzahlen dienen klassische Parameter der beschreibenden Statistik (Mittel, Minimum, Maximum, Standardabweichung und Variationskoeffizient) für einen definierten rechteckigen Bereich und für die zentrale vertikale Achse.
Ergebnisse: In einer Präliminarserie von 18 Augen war eine automatisierte Messung mit korrekter Pupillenerkennung in 80% der Fälle möglich. Verglichen mit der hersteller-eigenen Software (Pentacam 6.03r11) besitzt das eigene Programm eine erweiterte Spannweite der Messwerte. Die Messwerte können automatisch nach Excel (Microsoft) exportiert werden. Ein modularer Aufbau ermöglicht eine flexible Erweiterung für weitere Fragestellungen (z.B. Quantifizierung von Kern- und Rindentrübungen).
Schlussfolgerungen: Mittels eines selbst programmierten MATLAB-basierten Programmes kann eine automatisierte Messung und Analyse von linsndensitometrischen Parametern durchgeführt werden.
Im Rahmen des Vortrags wird zunächst ein Überblick über die aktuell angewandten Linsensysteme in der (refraktiven) Kataraktchirurgie sowie im Rahmen des RLA gesprochen. Hierzu zählen die monofokalen sphärischen Standardlinsen, aber auch asphärische, torische und multifokale Implantate.
Speziell wird auf die Ergebnisse einer Studie zu einem neuen multifokalen-torischen Implantat eingegangen. Der Schwerpunkt des Vortrages liegt dann weiterhin auf den trifokalen Korrektionsmöglichkeiten. Zum einen wird die sog. binokulare Trifokalität, bei der zwei multifokale Intraokularlinsen unterschiedlicher Addition implantiert werden, besprochen. Durch die Anpassung jeweils eines Auges an den Intermediär- bzw. Nahbereich soll so bei verringerten optischen Phänomenen ein deutliches Sehen in drei Hauptdistanzen ermöglicht werden. Weiterhin befasst sich der Vortrag aber auch mit den neuen echten trifokalen Optiksystemen, welche ebenfalls deutliches Sehen in verschiedenen Entfernungen gewährleisten können.
Im dritten Teil des Vortrages werden aktuelle Langzeitergebnisse aus einer FDA Studie zur Evaluation einer kammerwinkelgestützten phaken Intraokularlinse, mit speziellem Augenmerk auf den cornealen Endothelzellverlust, sowie eine neuartige sulcusgestütze phake Intraokularlinse mit zentralem Loch zur Glaukomvermeidung vorgestellt.
Die exakte Positionierung von Intraokularlinsen in den Kapselsack ist von entscheidender Bedeutung für das postoperative visuelle Ergebnis nach Kataraktoperation oder refraktivem Linsenaustausch. Schon leichte Dezentrierungen können optische Aberrationen hervorrufen welche das Sehen der Patienten negativ beeinflussen. Besonders kommt dieses Phänomen bei sog. Premium Intraokularlinsen mit speziellen Optiken (asphärisch, torisch oder multifokal, sowie Kombinationen dieser) zum Tragen. Diese Optiken können Ihre gewünschte Wirkung nur bei exakter Positionierung entfalten. Eine postoperative Feinpositionierung ist nicht möglich, was die Ansprüche an den Operateur bei Implantation der Linsen erhöht. Minimalinvasive microinzisionelle Operationstechniken bieten heute gute Möglichkeiten, die Implantate exakt zu positionieren. Neben den Dezentrierungen können Intraokularlinsen auch dislozieren, beispielweise durch intra- oder postoperative Kapselrupturen, Linsenverziehungen oder auch Rotation der Implantate. Hier ist ein weiterer chirurgischer Eingriff von Nöten. Der Vortrag stellt dementsprechend verschiedene Videos und praktische Hinweise zur Handhabung postoperativer Linsendislokationen vor.
Background: Undergoing systemic inflammation, the innate immune system releases excessive proinflammatory mediators, which finally can lead to organ failure. Pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and NOD-like receptors (NLRs), form the interface between bacterial and viral toxins and innate immunity. During sepsis, patients with diagnosed adrenal gland insufficiency are at high risk of developing a multiorgan dysfunction syndrome, which dramatically increases the risk of mortality. To date, little is known about the mechanisms leading to adrenal dysfunction under septic conditions. Here, we investigated the sepsis-related activation of the PRRs, cell inflammation, and apoptosis within adrenal glands.
Methods: Two sepsis models were performed: the polymicrobial sepsis model (caecal ligation and puncture (CLP)) and the LTA-induced intoxication model. All experiments received institutional approval by the Regierungspräsidium Darmstadt. CLP was performed as previously described [1], wherein one-third of the caecum was ligated and punctured with a 20-gauge needle. For LTA-induced systemic inflammation, TLR2 knockout (TLR2-/-) and WT mice were injected intraperitoneally with pure LTA (pLTA; 1 mg/kg) or PBS for 2 hours. To detect potential direct adrenal dysfunction, mice were additionally injected with adrenocorticotropic hormone (ACTH; 100 μg/kg) 1 hour after pLTA or PBS. Adrenals and plasma samples were taken. Gene expressions in the adrenals (rt-PCR), cytokine release (multiplex assay), and the apoptosis rate (TUNEL assay) within the adrenals were determined.
Results: In both models, adrenals showed increased mRNA expression of TLR2 and TLR4, various NLRs, cytokines as well as inflammasome components, NADPH oxidase subunits, and nitric oxide synthases (data not shown). In WT mice, ACTH alone had no effect on inflammation, while pLTA or pLTA/ACTH administration showed increased levels of the cytokines IL-1β, IL-6, and TNFα. TLR2-/- mice indicated no response as expected (Figure 1, left). Interestingly, surviving CLP mice showed no inflammatory adrenal response, whereas nonsurvivors had elevated cytokine levels (Figure 1, right). Additionally, we identified a marked increase in apoptosis of both chromaffin and steroid-producing cells in adrenal glands obtained from mice with sepsis as compared with their controls (Figure 2).
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Conclusion: Taken together, sepsis-induced activation of the PRRs may contribute to adrenal impairment by enhancing tissue inflammation, oxidative stress and culminate in cellular apoptosis, while mortality seems to be associated with adrenal inflammation.
Background: Nerve injury induced protein 1 (Ninjurin 1 (Ninj1)) was first identified in Schwann cells and neurons contributing to cell adhesion and nerve regeneration. Recently, the role of Ninj1 has been linked to inflammatory processes in the central nervous system where functional repression reduced leukocyte infiltration and clinical disease activity during experimental autoimmune encephalomyelitis in mice [1]. But Ninj1 is also expressed outside the nervous system in various organs such as the liver and kidney as well as on leukocytes [2,3]. Therefore, we hypothesized that Ninj1 contributes to inflammation in general; that is, also outside the nervous system, with special interest in the pathogenesis of sepsis.
Methods: Ninj1 was repressed by transfecting HMEC-1 cells, a human dermal microvascular endothelial cell line with siRNA targeting Ninj1 (siNinj1) or a negative control (siC). Subsequently, cells were stimulated with 100 ng/ml LPS (TLR4 agonist), 3 μg/ml LTA (TLR2 agonist) or 100 n/ml poly(I:C) (TLR3 agonist) for 3 hours. The inflammatory response was analyzed by real-time PCR. In addition, transmigration of neutrophils across a HMEC-1 monolayer was measured using transwell plates (pore size 3 μm).
Results: Repression of Ninj1 by siRNA reduced Ninj1 mRNA expression in HMEC about 90% (Figure 1A). Reduced Ninj1 expression decreased neutrophil migration to 62.5% (Figure 1B) and TLR signaling. In detail, knockdown of Ninj1 significantly reduced TLR-2 and TLR-4 triggered expression of ICAM-1 and IL-6 (Figure 1C,D) while poly(I:C)-induced expression was only slightly reduced. To analyze a more specific TLR-3 target, we measured IP-10 mRNA expression, which was also significantly reduced in siNinj1-transfected cells (Figure 1E).
Conclusion: Our in vitro data strongly indicated that Ninj1 is involved in regulation of TLR signaling and therewith contributes to inflammation. In vivo experiments will clarify its impact on systemic inflammation.
Einleitung: Es wurden die Leistungen beim Verstehen im Störgeräusch von CI-Patienten mit unterschiedlichen Implantattypen verglichen. Der TEMPO+ Sprachprozessor (MED-EL, Implantat C40+) verwendet ein Mikrophon mit Kugelcharakteristik, während der ESPrit 3G Prozessor (COCHLEAR, Implantat CI24R(CA)) mit einem frontal ausgelegten Richtmikrophon ausgestattet ist.
Methode: Von den zwei untersuchten Patientengruppen (n=20) war eine mit einem C40+ Implantat (MED-EL, Innsbruck), die andere mit dem CI24RCA Implantat (Cochlear, Melbourne) versorgt. Es wurde die S0N180 Lautsprecheranordnung im Freifeld für den HSM-Test (Hochmair, Schulz und Moser, 1997) und die S0N0 Anordnung für den Oldenburger Satztest (Wagener, Kühnel und Kollmeier, 1999) verwendet. Der OLSA wurde mit festem Sprachpegel (65 dB SPL) und adaptivem Störgeräusch durchgeführt. Der HSM-Satztest wurde bei Signal-/ Rauschverhältnissen von 15 dB, 10 dB, 5 dB, 0dB sowie ohne Störgeräusch durchgeführt.
Ergebnisse: Im HSM-Satztest (S0N180) wurden signifikant bessere Leistungen beim Verstehen im Störgeräusch für die Gruppe mit dem Richtmikrophon nachgewiesen. Im Oldenburger Satztest zeigten sich keine signifikanten Unterschiede.
Schlussfolgerungen: Im Vergleich zu einem Mikrophon mit Kugelcharakteristik verbessert ein Richtmikrophon das Sprachverstehen in Situationen, in denen die Sprache frontal und der Störschall von hinten dargeboten werden.
Einleitung: Lokoregionäre Rezidivtumore der Kopf-Hals-Region können häufig nicht mehr kurativ operativ oder radiotherapeutisch behandelt werden, so dass neue Therapiekonzepte erforderlich sind. Es konnte gezeigt werden, dass statische Magnetfelder (SMF) Tumorwachstum und -angiogenese signifikant beeinflussen und zu einem intratumoralen Ödem führen. Das Ziel der vorliegenden Studie war die Evaluation des Effektes von SMF auf die Permeabilität von Tumorblutgefäßen und die therapeutische Nutzbarkeit in Kombination mit einer konventionellen Chemotherapie.
Methoden: Zellen eines syngenen amelanotischen Melanoms wurden in transparente Rückenhautkammern bei Goldhamstern implantiert. Unter SMF-Exposition von 587 mT wurde fluoreszenzmikroskopisch die Extravasation von rhodaminmarkiertem Albumin zur Errechnung der Gefäßpermeabilität gemessen und intratumorale Leukozyten-Endothelzell-Interaktionen quantifiziert. Für die anschließende Therapiestudie wurden die antitumoralen Effekte einer Kombinationstherapie von Paclitaxel und SMF-Exposition verglichen mit drei Kontrollgruppen (Glucose, Paclitaxel allein, SMF allein; je n=6).
Ergebnisse: SMF führen zu einer signifikanten Erhöhung der Tumorblutgefäßpermeabilität bei unveränderten Leukozyten-Endothelzell-Interaktionen. Die Kombinationstherapie von SMF und Paclitaxel ist – bezogen auf Tumorwachstum und Angiogenese – Monotherapien überlegen.
Schlussfolgerung: Eine SMF-induzierte Steigerung der Gefäßpermeabilität kann die Blut-Tumor-Schranke beeinflussen und somit die Effektivität einer Chemotherapie mit kleinmolekularen Substanzen wie Paclitaxel deutlich steigern. Bei Verwendung von Kopfspulen erscheint eine derartige adjuvante Kombinationstherapie für lokoregionäre Karzinomrezidive der Kopf-Hals-Region besonders geeignet.
CONTENTS: Keynote Address and Invited Plenary Lectures Symposia Debates and Panels Oral Presentations and Specific Topics Poster Presentations Workshop Presentations Case Study Presentations and Media Presentations Symposien Workshops
TRENTOOL : an open source toolbox to estimate neural directed interactions with transfer entropy
(2011)
To investigate directed interactions in neural networks we often use Norbert Wiener's famous definition of observational causality. Wiener’s definition states that an improvement of the prediction of the future of a time series X from its own past by the incorporation of information from the past of a second time series Y is seen as an indication of a causal interaction from Y to X. Early implementations of Wiener's principle – such as Granger causality – modelled interacting systems by linear autoregressive processes and the interactions themselves were also assumed to be linear. However, in complex systems – such as the brain – nonlinear behaviour of its parts and nonlinear interactions between them have to be expected. In fact nonlinear power-to-power or phase-to-power interactions between frequencies are reported frequently. To cover all types of non-linear interactions in the brain, and thereby to fully chart the neural networks of interest, it is useful to implement Wiener's principle in a way that is free of a model of the interaction [1]. Indeed, it is possible to reformulate Wiener's principle based on information theoretic quantities to obtain the desired model-freeness. The resulting measure was originally formulated by Schreiber [2] and termed transfer entropy (TE). Shortly after its publication transfer entropy found applications to neurophysiological data. With the introduction of new, data efficient estimators (e.g. [3]) TE has experienced a rapid surge of interest (e.g. [4]). Applications of TE in neuroscience range from recordings in cultured neuronal populations to functional magnetic resonanace imaging (fMRI) signals. Despite widespread interest in TE, no publicly available toolbox exists that guides the user through the difficulties of this powerful technique. TRENTOOL (the TRansfer ENtropy TOOLbox) fills this gap for the neurosciences by bundling data efficient estimation algorithms with the necessary parameter estimation routines and nonparametric statistical testing procedures for comparison to surrogate data or between experimental conditions. TRENTOOL is an open source MATLAB toolbox based on the Fieldtrip data format. ...
Meeting Abstract : Deutsche Gesellschaft für Chirurgie. 125. Kongress der Deutschen Gesellschaft für Chirurgie. Berlin, 22.-25.04.2008 Einleitung: Ein wesentliches Ziel der modernen Perforatorlappen vom Unterbauch (DIEP-flap) für die Brustrekonstruktion nach Mammaamputation ist die Schonung der Rektusmuskulatur. Der Funktionserhalt der Muskulatur ist abhängig von der Präparationstechnik. In unserer Studie wird die Interaktion zwischen der Muskel- und Nervendurchtrennung und der postoperativen Muskelfunktion untersucht. Material und Methoden: Unser Patientenkollektiv umfasst 42 Patienten. Im Zeitraum von 6/04 bis 06/07 wurden 44 DIEP-Lappen an unserer Klink nach dem gleichen operativen Standard von unterschiedlichen Operateuren zur Brustrekonstruktion transferiert. Die Standards beinhalten die beidseitige Präparation der Perforatorgefäße des Unterbauches, der SIEA-Gefäße, die Auswahl der 2–4 kräftigsten Perforatoren einer Seite und die schonende Präparation der Rektusmuskulatur und der motorischen Nervenäste.In einer prospektiven monozentrischen Studie haben wir die Rektusmuskulatur präoperativ und 6 Monate postoperativ untersucht. Für die Funktionsanalyse wurde sowohl die Myosonografie der Rektusmuskulatur als auch eine klinischen Untersuchung angewandt. Intraoperativ wurde die Anzahl und Lokalisation der Perforatoren, die Länge der gespreizten Muskulatur, die Länge der durchtrennten Muskulatur und die Anzahl und Lokalisation der durchtrennten intramuskulären Nerven in einer Skizze eingetragen. Die Relation zwischen der intraoperativen Muskel- und Nervenschädigung und der postoperativen Funktion wurde analysiert. Ergebnisse: Bei der Hebung des DIEP – flaps wurden im Durchschnitt 10,8 cm Muskulatur gespreizt, 8,2 cm Muskulatur getunnelt und 2,5 cm Muskulatur durchtrennt. In 41% (18 Pat) wurde 1 motorischer Nervenast durchtrennt, in 27,3% (12 Pat) waren es 2 und in 13,6% (6 Pat) 3 Nervenäste. Bei der klinischen Untersuchung 6 Monate postoperativ hatten 8 Patientinnen noch funktionelle Störungen beim Heben schwerer Gegenstände. Myosonografisch fand sich bei 3 Patientinnen eine Funktionsminderung: 1 vollständiger Funktionsverlust der Muskulatur mit Relaxatio, 2 relevante Minderungen der Kontraktilität Bei keiner Patientin fand sich eine Bauchwandhernie. Bei allen Patientinnen mit einer Beeinträchtigung der Muskulatur waren mind. 2 motorische Nervenäste durchtrennt worden. Schlussfolgerung: Die klinische und myosonografische Funktionsanalyse der Bauchwand ermöglicht die Erstellung von Standards zur verbesserten Operationstechnik. Unsere Ergebnisse zeigen, dass die Durchtrennung von 2 oder mehr motorischen Nervenästen vermieden werden muß. Die Länge der durchtrennten und gespreizten Muskulatur ist dagegen von geringerer Bedeutung.
Einleitung: Die pathologische Stimulierbarkeit von Serum-Calcitonin (CT) im relativ niedrigen Bereich (über 100 bis 300 pg/ml) trennt nicht hinreichend zwischen C-Zell-Hyperplasie (CCH) und C-Zell-(Mikro-)Karzinom (CCC), bei Überwiegen der Fälle mit CCH. Der Schilddrüsenisthmus ist frei von C-Zellen (Lit. mult., eigene Studie). Dies führte zur Methode der ITBL , welche nun an einer größeren prospektiv dokumentierten Serie von Patienten evaluiert wird.
Material und Methoden: 102 Patienten mit präoperativ gering bis mäßig erhöhtem CT (stim.≥100 ≤400 pg/ml) wurden mit der Intention zur ITBL operiert. Bei 30 erfolgte die Komplettierung zur totalen Thyreoidektomie (TTX), davon 27 in gleicher Sitzung, im Fall von Malignität unter Einschluss der systematischen Lymphknotendissektion (LNX). Gründe zur Komplettierung waren Mikrokarzinome (12 medulläre, 7 differenzierte) oder benigne Isthmusknoten (n=11).
Ergebnisse: Bei allen 72 Patienten mit definitiver ITBL (darunter 2 Mikro-CCC, übrige CCH) lag, ebenso wie bei den 30 Patienten mit TTX, das postoperative CT unter der Messgrenze (unter 2 pg/ml), mit einer Ausnahme (3 pg/ml, nicht stimulierbar); maximal stim. CT war bei 5 der 72 Patienten im unteren Normbereich messbar (3 – 4,6 pg/ml), bei den übrigen ebenfalls unter der Messgrenze. Alle 102 Patienten waren "biochemisch geheilt".
Schlussfolgerung: Die ITBL hat sich mit hinreichender Sicherheit als optimale Operationsmethode für Fälle mit CCH erwiesen und ist bzgl. ihrer Radikalität der TTX gleichwertig, unter Belassung eines gesunden Schilddrüsenrestes (Isthmus) von funktioneller Relevanz (2 – 5 g).
Einleitung: Der Schlauchmagen (Sleeve Gastrectomy) wurde zunächst als erster Teil der biliopankreatischen Diversion mit Duodealswitch eingeführt, um das operative Risiko durch eine Zweischritt-Therapie zu senken. Zunehmend wird das Verfahren nun auch als eigeneständige Operation zur Gewichtsreduktion eingesetzt, obwohl noch keine Langzeitergebnisse vorliegen.
Material und Methoden: Im Zeitraum von 03/2001 bis 03/2007 wurden 120 Patienten (mittleres Alter: 40,3 Jahre; Geschlecht : 86 Frauen, 34 Männer ; Mittelwerte für Gewicht (179,8 kg), Körperlänge (1,72 m), BMI (60,7 kg/m2)Übergewicht (117,1 kg)mit einem laparoskopischen Schlauchmagenbildung behandelt. Die Ausgangssituation war zwischen den Gruppen nicht verschieden (Pearson). Bei 106 der Patienten war ein BPD-DS geplant, der in zwei Schritten erfolgen sollte. 6 Patienten hatten bereits vorher ein Magenband. In der Gruppe A (n=25) erfolgte keine Kalibration des Schlauches mit Hilfe einer Sonde. In Gruppe B (n=32) wurde eine 44 French und in Gruppe C (n=63) eine 33 French im Durchmesser starke Sonde zur Kalibration eingesetzt.
Ergebnisse: Intraoperativ wurden durch Volumenmessung über die Sonde die Schlauchvolumina mit einer hohen Varianz gemessen (A: 149,0 ml, SD: 15,2; B:117,4 ml, SD:34,8; C: 78,3 ml,SD: 17,9). Die Unterschiede waren statistisch signifikant (p<0,01; eta2=0,61). Besonders deutlich waren die Unterschiede im resezierten Magenvolumen (A:490,2 ml; B 732,7 ml; C:1156,1 ml). Da statistisch keine Abhängigkeit zwischen BMI und Magenvolumen nachgewiesen w erden konnte, zeigt sich die Ungenauigkeit der Schlauchmagenmessung gegenüber der Messung des resezierten Magenvolumens. Ergebnisse der Gewichtsreduktion zeigen eine Abhängigkeit von der Kalibration des Magenschlauches und des resezierten Magen-Volumens. Der Gewichtsverlust beträgt im Gesamtpatientengut und zeigt ab dem 3. Postoperativen Jahr eine Tendenz zum Wiederanstieg des Gewichtes. Eine unterlassene Kalibration und ein Volumen von weniger als 500 cm3 für den entfernten Magen sind mit einem Gewichtsanstieg spätestens nach 2- 3 Jahre verbunden. Der Verlust von 20 BMI-Punkten wird nach 2 Jahren erreicht.
Schlussfolgerung: Die Schlauchmagenbildung ist ein restriktives Verfahren, dass bei einer Kalibration eines engen Magenschlauches (32 French) und einem resezierten Magenvolumen von mindestens 500 eine sehr gute Gewichtsreduktion erzielt, die sich bei dem EWL zwischen de Ergebnissen des Magenbandes und des Magenbypass bewegt. Durch Anpassung der Ernährungsgewohnheiten kann es wie bei allen pur restriktiven Verfahren zu einem Wiederanstieg des Körpergewichtes.
Laparoskopische Gastrektomie
(2008)
Einleitung: Obwohl laparoskopische, resezierende Verfahren am Magen als atypische Wedge-Resektionen weitgehend etabliert sind, werden formale Magenresektionen eher selten laparoskopisch durchgeführt. Die Gründe sind die Komplexität formaler, laparoskopischer Magenresektionen und die Seltenheit geeigneter Indikationen. Das Video zeigt eine Gastrektomie bei einem pT2a Magenkarzinom. Material und Methoden: Die Operation erfolgt in „Liegestuhl-Lagerung“. Die Trokarplatzierung entspricht weitgehend der einer Fundoplikatio. Zunächst wird das Omentum majus vom Colon transversum abgelöst und die große Kurvatur und der Fundus mittels Ultraschalldissektion mobilisiert. Nach Lösen der retrogastralen Verklebungen wird das postpylorische Duodenum mobilisiert und mit dem GIA abgesetzt. Die Lymphadenektomie im Lig. Hepatoduodenale erfolgt von lateral nach medial, wobei die A.gastrica dexter abgesetzt wird. Lymphadenektomie kranial deer Al lienalis und radikuläres Absetzen der A.gastrica sin. Nach Mobilisierung des distalen Ösophagus offenes Absetzen desselben und Einküpfen eine 25mm Andruckplatte. Durchtrennen des Jejunums und Mesojejunums ca. 40 cm aboral von Treitz. Der Zirkularstapler wird durch eine Erweiterung der Trokarinzision im linken Oberbauch eingeführt und dann laparoskopisch die Krückstock-Anastomose gestaplet. Der Krückstock wird mit dem Linearstapler verschlossen und die Dichtigkeit mittels Methylenblauinstillation geprüft. Dann wird die erweiterte Trokarinzision zur Minilaparotomie erweitert und das Resektat geborgen, die Y-Roux-Anastomose erfolgt offen durch die Mini-Laparotomie. Ergebnisse: Die OP-Zeit der gezeigten OP betrug 270 min., der intraoperative Blutverlust 40 ml. Der postoperative Verlauf war komplikationslos, die postoperative Verweildauer betrug 8 Tage. Histologisch zeigte sich ein Siegelringkarzinom des Magens pT2a, pN0 (0/21) M0 G3 R0. Schlussfolgerung: Das Video demonstriert, dass die laparoskopische Gastrektomie mit guter Übersicht sicher durchführbar ist.
Einleitung: Die Diagnostik kindlicher Knieverletzungen wird heutzutage häufig durch die Kernspintomographie ergänzt, um relevante Kniebinnenschäden zu erkennen. Der klinische Nutzen dieser Zusatzuntersuchung wird in Abhängigkeit vom Beschwerdebild des Patienten und in Relation zum apparativen und wirtschaftlichen Aufwand unterschiedlich bewertet. Ziel dieser Studie war es, die Bedeutung der Kernspintomographie in Abhängigkeit von der klinischen Verdachtsdiagnose und dem arthroskopischen Befund zu bewerten.
Material und Methoden: Es wurden insgesamt 195 Patienten im Alter von 3 bis 17 Jahren in diese Studie aufgenommen. 83 dieser Patienten wurden aufgrund der klinischen Diagnose unmittelbar der Kernspintomographie zugeführt. 165 der Patienten wurden, entweder aufgrund der klinischen Untersuchung, oder aufgrund des Befunds der Kernspintomographie, arthroskopiert.
Ergebnisse: Die klinische Verdachtsdiagnose wurde bei 117 der 165 Patienten (71%), bei denen eine Arthroskopie durchgeführt wurde, bestätigt. Die größten Übereinstimmungen der Diagnosen in den unterschiedlichen Verfahren gab es dabei bei der Verdachtsdiagnose Patellaluxation (87%) und bei der Verdachtsdiagnose ligamentäre Verletzung (74%). Die Verdachtsdiagnose einer Meniskusläsion brachte eine Übereinstimmung von 48%.Von den 83 Patienten, bei denen eine kernspintomographische Untersuchung durchgeführt wurde, wurden daraufhin 53 Patienten arthroskopiert und 30 Patienten konservativ behandelt. Der MRT Befund wurde in der durchgeführten Arthroskopie bei 42 Patienten (81%) bestätigt. Die MRT Diagnose Patellaluxation wurde hierbei in allen Fällen (100%) in der Arthroskopie bestätigt. Die Übereinstimmungen der Kernspindiagnose einer ligamentären Läsion lag bei 83% und die Übereinstimmung bei der Meniskusverletzung bei 56%.Bei den 30 Patienten, die ausschließlich die Kernspintomographie erhielten und daraufhin konservativ behandelt wurden, wurden hauptsächlich Band- und Meniskuseinblutungen (37%) und extraartikuläre Veränderungen wie Bone Bruise, Fibrom oder Exostose (13%) im MRT diagnostiziert. Letztlich konnte durch den Einsatz der Kernspintomographie der Anteil der rein diagnostischen Arthroskopien von 22% auf 13% reduziert werden.
Schlussfolgerung: Bei klinischem Verdacht auf eine Meniskus- oder Bandverletzung ist die Kernspintomographie ein wertvolles Hilfsmittel zur Überprüfung der Diagnose, da häufig klinisch keine sichere Beurteilung möglich ist. Bei der klinischen Verdachtsdiagnose einer Patellaluxation ist die Kernspintomographie zur Diagnosesicherung selten erforderlich, kann jedoch zur Beurteilung von Begleitverletzungen (z.B. Flake Frakturen) wertvolle Zusatzinformationen liefern. Bei klinisch unklarem Befund kann die Anzahl rein diagnostischer Arthroskopien deutlich gesenkt werden.
The nervous system probably cannot display macroscopic quantum (i.e. classically impossible) behaviours such as quantum entanglement, superposition or tunnelling (Koch and Hepp, Nature 440:611, 2006). However, in contrast to this quantum "mysticism" there is an alternative way in which quantum events might influence the brain activity. The nervous system is a nonlinear system with many feedback loops at every level of its structural hierarchy. A conventional wisdom is that in macroscopic objects the quantum fluctuations are self-averaging and thus not important. Nevertheless this intuition might be misleading in the case of nonlinear complex systems. Because of a high sensitivity to initial conditions, in chaotic systems the microscopic fluctuations may be amplified upward and thereby affect the system’s output. In this way stochastic quantum dynamics might sometimes alter the outcome of neuronal computations, not by generating classically impossible solutions, but by influencing the selection of many possible solutions (Satinover, Quantum Brain, Wiley & Sons, 2001). I am going to discuss recent theoretical proposals and experimental findings in quantum mechanics, complexity theory and computational neuroscience suggesting that biological evolution is able to take advantage of quantum-computational speed-up. I predict that the future research on quantum complex systems will provide us with novel interesting insights that might be relevant also for neurobiology and neurophilosophy.
Meeting Abstract : Deutsche Gesellschaft für Chirurgie. 125. Kongress der Deutschen Gesellschaft für Chirurgie. Berlin, 22.-25.04.2008 Einleitung: Beim follikulären Schilddrüsenkarzinom ist die prae- und intraoperative Diagnose nur eingeschränkkt möglich. Immunhistochemische und immuncytologische Marker können hier hilfreich sein. Bei Patienten mit follikulären Karzinomen ist auf mRNA-Ebene eine up-Regulation für qprt (quinolinate-phosphoribosyltransferase) zu beobachten. Material und Methoden: Seit Januar 2004 werden bei Patienten mit prae- und intraoperativem Verdacht auf Schilddrüsenkarzinom, Frischgewebeproben zur Genexpressions-Analyse asserviert. Die so gewonnen Ergebnisse wurden an prospektiv und retrospektiv gewonnenen Präparaten von follikulären Adenomen und follikulären Karzinomen überprüft [Gruppe A]. Bei 20 prospektiven Punktionscytologien mit follikulärer Neoplasie werden aktuell zusätzliche immuncytologische Färbungen auf qprt durchgeführt und mit den nachfolgenden histologischen und immunhistochemischen Ergebnissen der Operationspräparate verglichen. Ergebnisse: Gruppe A (151 Patienten): bei 79 follikulären Adenomen und 72 follikulären Karzinomen wurden immunhistochemische Färbungen auf qprt durchgeführt. Hier zeigten sich 60 der 79 Adenome richtig negativ (76%) und 47 der 72 Karzinome richtig positiv (66%). Dies ergab eine Treffsicherheit zwischen Adenom und Karzinom von 71%. Gruppe B (20 Patienten): Die Ergebnisse der Korrelation zwischen präoperativer Immuncytochemie und postoperativer Diagnose und Immunhistochemie stehen derzeit noch aus. Schlussfolgerung: qprt ist ein immunhistochemischer Marker für follikuläre Schilddrüsenkarzinome mit einer befriedigenden Trennschärfe zwischen Adenom und Karzinom. Zusätzlich stellt qprt möglicherweise einen aussagekräftigen präoperativen immuncytochemischen Marker mit Auswirkung auf OP-Zeitpunkt, OP-Verfahren und OP-Taktik dar.
Meeting Abstract : Deutscher Kongress für Orthopädie und Unfallchirurgie ; 73. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie ; 95. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie ; 50. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie ; 21. - 24.10.2009, Berlin Fragestellung: Ziel war die Evaluierung der funktionellen und radiologischen Ergebnisse nach osteosynthestischer Versorgung von Olecranonfrakturen mit einer zur Hakenplatte modifizierten Drittelrohrplatte. Methodik: In einem Zeitraum von 12 Monaten wurden 29 Patienten mit Olecranonfrakturen prospektiv erfasst und eine Osteosynthese mit einer zur Hakenplatte modifizierten Kleinfragment-Drittelrohrplatte durchgeführt. Eine additive Verschraubung von zusätzlichen Fragmenten erfolgte bei 6 Patienten (20%). Das mittlere Patientenalter zum Unfallzeitpunkt betrug 50 Jahre (Min 29/ Max 83). Unter Verwendung der Frakturklassifikation nach Schatzker stellte sich in 8 Fällen (28%) eine Querfraktur vom Typ A, in 6 Fällen (20%) eine Querfraktur mit Impaktion vom Typ B und in 15 Fällen (52%) eine Mehrfragmentfraktur vom Typ D dar. Bei 4 Patienten (14%) lag eine offene Fraktursituation vor. Nach im Mittel 7,2 Monaten (Min 6/ Max 8) wurde das funktionelle Outcome anhand des Mayo Elbow Performence Scores (MEPS), der visuellen Analogskala (VAS) und des Disabilities of the Arm, Shoulder and Hand Scores (DASH) bewertet sowie die radiologischen Befunde erhoben. Ergebnisse und Schlussfolgerungen: Das Ziel einer primär übungsstabilen Osteosynthese konnte bei allen Patienten erreicht werden. Unter Verwendung des MEPS wurden annähernd ausschließlich sehr gute (12 Fälle/41%) und gute (16 Fälle/55%) Ergebnisse erzielt. Lediglich bei einem Patienten ergab sich ein nur befriedigendes Ergebnis. Der mittlere Punktwert für den MEPS betrug 91,4 (Min 65/Max 100). In der VAS konnte ein Mittelwert von 8,2 Punkten (Min 7/Max 10) erzielt werden (0=keine Zufriedenheit, 10=volle Zufriedenheit). Der mittlere DASH-Wert betrug 16,2 Punkte (Min 0/Max 39). Der mittlere Bewegungsumfang betrug für Extension/Flexion bei einem durchschnittlichen Streckdefizit von 8° (Min 0°/Max 25°) und einer Beugung von 135° (Min 105°/Max 155°) 125° (Min 90°/Max 155°). Die Unterarmumwendbewegungen waren mit 175° (Min 165°/Max 180°) kaum eingeschränkt. Bei keinem Patienten gab es postoperative Komplikationen. Eine zur Hakenplatte modifizierte Drittelrohrplatte stellt im Gegensatz zu präformierten, winkelstabilen Implantaten eine kostengünstige Alternative zur Osteosynthese bei Olecranonfrakturen dar. Auch bei komplexen mehrfragmentären Frakturtypen und osteoporotischer Knochenqualität konnte so im nachuntersuchten Kollektiv eine sichere Frakturretention erzielt werden. Hinsichtlich des funktionellen Ergebnisses profitieren die Patienten von einer dadurch unmittelbar postoperativ möglichen, physiotherapeutischen Nachbehandlung. Das für die Hakenplatte benötigte Osteosynthesematerial (Kleinfragment-Drittelrohrplatte) ist nahezu überall verfügbar und lässt sich in kurzer Zeit der individuellen Anatomie und Frakturmorphologie anpassen. Eine Drahtmigration, wie bei der weit verbreiteten Zuggurtungsosteosynthese häufig beobachtet, ist ausgeschlossen.