Medizin
Refine
Year of publication
- 2016 (316) (remove)
Document Type
- Article (282)
- Doctoral Thesis (14)
- Part of Periodical (11)
- Book (4)
- Contribution to a Periodical (3)
- Conference Proceeding (1)
- Preprint (1)
Has Fulltext
- yes (316)
Is part of the Bibliography
- no (316)
Keywords
Institute
- Medizin (316)
- Präsidium (11)
- Biowissenschaften (8)
- Exzellenzcluster Makromolekulare Komplexe (6)
- Biochemie und Chemie (5)
- Pharmazie (5)
- Sonderforschungsbereiche / Forschungskollegs (4)
- Georg-Speyer-Haus (3)
- MPI für Hirnforschung (3)
- Sportwissenschaften (3)
Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is an uncommon disorder of unknown etiology affecting the retina, the retinal pigment epithelium, and the choroid. Although several etiological factors have been suggested, none has been confirmed. We report a case of APMPPE associated with acute infection of Borreliosis. A 30-year-old man presented with a decrease in vision in the right eye of about 1-week duration. His visual acuity in the right eye was 6/36. Fundus exam revealed the presence of multiple placoid creamy retinal/subretinal lesions in the right eye. Fundus fluorescein angiography supported the diagnosis of APMPPE. Blood tests revealed the presence of concomitant acute Borreliosis infection, as confirmed by IgM. The patient received oral prednisone therapy and amoxicillin. Six weeks later, the visual acuity returned to 6/6, and the patient was symptom free. Borreliosis can have several manifestations in the eye. One of the less common presentations is an APMPPE-like picture. The clinician should suspect acute Borreliosis infection in patients presenting with APMPPE, especially when there is a history of a tick bite, when the patient has systemic symptoms, or when living in/visiting endemic areas. This may help in the prompt management of APMPPE, avoiding complications due to the condition itself, or systemic involvement secondary to the Borreliosis infection.
Background: NH exchangers (NHEs) play a crucial role in regulating intra/extracellular pH, which is altered in cancer cells, and are therefore suitable targets to alter cancer cell metabolism in order to inhibit cell survival and proliferation. Among NHE inhibitors, amiloride family members are commonly used in clinical practice as diuretics; we focused on the amiloride HMA, reporting a net cytotoxic effect on a panel of human cancer cell lines; now we aim to provide new insights into the molecular events leading to cell death by HMA.
Methods: Colon cancer cell lines were treated with HMA and analysed with: morphological and cellular assays for cell viability and death, and autophagy; biochemical approaches to evaluate mitochondrial function and ROS production; in situ detection of DNA damage; molecular tools to silence crucial autophagy/necroptosis factors.
Results: HMA affects cellular morphology, alters mitochondrial structure and function, causes an increase in ROS, which is detrimental to DNA integrity, stimulates poly(ADP-ribose) synthesis, activates RIPK3-dependent death and triggers autophagy, which is unable to rescue cell survival. These features are hot points of an intricate network of processes, including necroptosis and autophagy, regulating the homeostasis between survival and death.
Conclusion: Our results allow the identification of multiple events leading to cell death in cancer cells treated with HMA. The here-defined intricate network activated by HMA could be instrumental to selectively target the key players of each pathway in the attempt to improve the global response to HMA. Our data could be the starting point for developing a newly designed targeted therapy.
BACKGROUND: Geographical variation of the general practitioner (GP) workforce is known between rural and urban areas. However, data about the variation between and within urban areas are lacking.
METHOD: We analyzed distribution patterns of GP full time equivalents (FTE) in German cities with a population size of more than 500,000. We correlated their distribution with area measures of social deprivation in order to analyze preferences within neighborhood characteristics. For this purpose, we developed two area measures of deprivation: Geodemographic Index (GDI) and Cultureeconomic Index (CEI).
RESULTS: In total n = 9034.75 FTE were included in n = 14 cities with n = 171 districts. FTE were distributed equally on inter-city level (mean: 6.49; range: 5.12-7.20; SD: 0.51). However, on intra-city level, GP distribution was skewed (mean: 6.54; range: 1.80-43.98; SD: 3.62). Distribution patterns of FTE per 10^4 residents were significantly correlated with GDI (r = -0.49; p < 0.001) and CEI (r = -0.22; p = 0.005). Therefore, location choices of GPs were mainly positively correlated with 1) central location (r = -0.50; p < 0.001), 2) small household size of population (r = -0.50; p < 0.001) and 3) population density (r = 0.35; p < 0.001).
CONCLUSION: Intra-city distribution of GPs was skewed, which could affect the equality of access for the urban population. Furthermore, health services planners should be aware of GP location preferences. This could be helpful to better understand and plan delivery of health services. Within this process the presented Geodemographic Index (GDI) could be of use.
BACKGROUND: Local implantation of ex vivo concentrated, washed and filtrated human bone marrow-derived mononuclear cells (BMC) seeded onto β-tricalciumphosphate (TCP) significantly enhanced bone healing in a preclinical segmental defect model. Based on these results, we evaluated in a first clinical phase-I trial safety and feasibility of augmentation with preoperatively isolated autologous BMC seeded onto β-TCP in combination with angle stable plate fixation for the therapy of proximal humeral fractures as a potential alternative to autologous bone graft from the iliac crest.
METHODS: 10 patients were enrolled to assess whether cell therapy with 1.3 × 106 autologous BMC/ml/ml β-TCP, collected on the day preceding the definitive surgery, is safe and feasible when seeded onto β-TCP in patients with a proximal humeral fracture. 5 follow-up visits for clinical and radiological controls up to 12 weeks were performed.
RESULTS: β-tricalciumphosphate fortification with BMC was feasible and safe; specifically, neither morbidity at the harvest site nor at the surgical wound site were observed. Neither local nor systemic inflammation was noted. All fractures healed within the observation time without secondary dislocation. Three adverse events were reported: one case each of abdominal wall shingles, tendon loosening and initial screw perforation, none of which presumed related to the IND.
CONCLUSIONS: Cell therapy with autologous BMC for bone regeneration appeared to be safe and feasible with no drug-related adverse reactions being described to date. The impression of efficacy was given, although the study was not powered nor controlled to detect such. A clinical trial phase-II will be forthcoming in order to formally test the clinical benefit of BMC-laden β-TCP for PHF patients. Trial registration The study was registered in the European Clinical Trial Register as EudraCT No. 2012-004037-17. Date of registration 30th of August 2012. Informed consent was signed from all patients enrolled.
Background: In Europe, the number of females exhibiting oppositional defiant disorder (ODD) and conduct disorder (CD) is growing. Many of these females live in youth welfare institutions. Consequently, there is a great need for evidence-based interventions within youth welfare settings. A recently developed approach targeting the specific needs of girls with ODD and CD in residential care is START NOW. The aim of this group-based behavioural skills training programme is to specifically enhance emotional regulation capacities to enable females with CD or ODD to appropriately deal with daily-life demands. It is intended to enhance psychosocial adjustment and well-being as well as reduce oppositional and aggressive behaviour. We present the study protocol (version 4.1; 10 February 2016) of the FemNAT-CD intervention trial titled "Group-Based Treatment of Adolescent Female Conduct Disorders: The Central Role of Emotion Regulation".
Methods/design: The study is a prospective, confirmatory, cluster-randomised, parallel-group, multi-centre, randomised controlled trial with 128 institutionalised female adolescents who fulfil the diagnostic criteria of ODD and/or CD. Institutions/wards will be randomised either to provide the 12-week skills training as an add-on intervention or to provide treatment as usual. Once the first cycle is completed, each institution will run a second cycle with the opposite condition. Primary endpoints are the pre-post change in number of CD/ODD symptoms as assessed by a standardised, semi-structured psychiatric interview (Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children–Present and Lifetime, CD/ODD section) between baseline and the end of intervention, as well as between baseline and a 3-month follow-up point. Secondary objectives include pre-post change in CD/ODD-related outcome measures, most notably emotional regulation on a behavioural and neurobiological level after completion of START NOW compared with treatment as usual.
Discussion: To our knowledge, this study is the first to date to systematically investigate the effectiveness of an adapted integrative psychosocial intervention designed for female adolescents with ODD and CD in youth welfare settings.
Trial registration: German Clinical Trials Register (DRKS) identifier: DRKS00007524. Registered on 18 December 2015 and with the World Health Organisation International Clinical Trials Registry Platform.
Aim: Exposure to opioids has been associated with epigenetic effects. Studies in rodents suggested a role of varying degrees of DNA methylation in the differential regulation of μ-opioid receptor expression across the brain.
Methods: In a translational investigation, using tissue acquired postmortem from 21 brain regions of former opiate addicts, representing a human cohort with chronic opioid exposure, μ-opioid receptor expression was analyzed at the level of DNA methylation, mRNA and protein.
Results & conclusion: While high or low μ-opioid receptor expression significantly correlated with local OPRM1 mRNA levels, there was no corresponding association with OPRM1 methylation status. Additional experiments in human cell lines showed that changes in DNA methylation associated with changes in μ-opioid expression were an order of magnitude greater than differences in brain. Hence, different degrees of DNA methylation associated with chronic opioid exposure are unlikely to exert a major role in the region-specificity of μ-opioid receptor expression in the human brain.
Kardiovaskuläre Erkrankungen stellen in Deutschland die häufigste Todesursache dar [1]. Eine Schlüsselrolle wird hierbei der koronaren Herzkrankheit (KHK) auf dem Boden einer Atherosklerose zuteil. Die Prävalenz der koronaren Herzkrankheit in Deutschland lag 2012 laut Zahlen des Robert Koch-Instituts bei 8,3 %; dies entspricht 6,64 Millionen Menschen. Die Spitzengruppe bilden die über 65-Jährigen mit einer Erkrankungshäufigkeit von 18,3 % bei Frauen und 27,8 % bei Männern. Oberstes Therapieziel bei der Behandlung der KHK ist die Prävention von Myokardinfarkten und Herzinsuffizienz. Wegweisend für das therapeutische Procedere sind die klinische Situation des Patienten und die Ergebnisse der kardialen Diagnostik. Sind mehrere Koronargefäße betroffen oder bestehen komplizierte Gefäßverengungen ist die Indikation zur operativen Myokardrevaskularisierung gegeben. Im Jahr 2015 unterzogen sich in Deutschland 51.941 Patienten einem solchen Eingriff [2]; weltweit erhalten jährlich fast eine Millionen Patienten eine Bypass-Operation [3]. Für den Therapieerfolg ist postoperativ eine suffiziente Thrombozytenaggregationshemmung von essentieller Bedeutung. Daher wird zur Sekundärprophylaxe eine lebenslange antiaggregatorische Medikation empfohlen; das am häufigsten hierfür genutzte Medikament ist Acetylsalicylsäure (ASS) [4]....
Ziel der vorliegenden Studie war, mittels MEA, die Prävalenz und mögliche Prädiktoren einer ASS-Nonresponse in einer Kohorte kardiochirurgischer Patienten zu analysieren.
Es wurden folgende Nullhypothesen aufgestellt:
- Die tägliche Einnahme von 100 mg ASS ist ausreichend, um bei allen Patienten eine therapeutische Thrombozytenaggregationshemmung zu erreichen.
- Es existieren keine Prädiktoren für die mittels MEA detektierte ASSNonresponse.
Targeting key angiogenic pathways with a bispecific CrossMAb optimized for neovascular eye diseases
(2016)
Anti-angiogenic therapies using biological molecules that neutralize vascular endothelial growth factor-A (VEGF-A) have revolutionized treatment of retinal vascular diseases including age-related macular degeneration (AMD). This study reports preclinical assessment of a strategy to enhance anti-VEGF-A monotherapy efficacy by targeting both VEGF-A and angiopoietin-2 (ANG-2), a factor strongly upregulated in vitreous fluids of patients with retinal vascular disease and exerting some of its activities in concert with VEGF-A. Simultaneous VEGF-A and ANG-2 inhibition was found to reduce vessel lesion number, permeability, retinal edema, and neuron loss more effectively than either agent alone in a spontaneous choroidal neovascularization (CNV) model. We describe the generation of a bispecific domain-exchanged (crossed) monoclonal antibody (CrossMAb; RG7716) capable of binding, neutralizing, and depleting VEGF-A and ANG-2. RG7716 showed greater efficacy than anti-VEGF-A alone in a non-human primate laser-induced CNV model after intravitreal delivery. Modification of RG7716’s FcRn and FccR binding sites disabled the antibodies’ Fc-mediated effector functions. This resulted in increased systemic, but not ocular, clearance. These properties make RG7716 a potential nextgeneration therapy for neovascular indications of the eye.
The aim of this clinical study was to describe the quality of posterior composite restorations (n = 329) performed on a group of patients (n=219) during an observation period of three years at various intervals (6, 12, 18, 24 and 36 months) after application.
The parameters were assessed both In vivo and In vitro using clinical examinations, impressions and photography according to modified FDI criteria. For the statistical analysis of the results, the Wilcoxon test with a significance level of p = 0.05 was applied.
After three years, In vivo five from the seven parameters exhibited significant changes. Only "retention" and "approximal contact" remained unchanged. In vitro studied parameters "anatomical form", "occlusal contour/wear" and "approximal contact" did not result in any significant changes, however "marginal adaptation", "surface luster" and "overhangs" deteriorated significantly.
In summary, the results of this study show that composite posterior restorations were clinically acceptable in terms of specific parameters. However, unsatisfactory results have arisen in relation to the handling of composites, stated In vivo and In vitro especially in the reconstruction of the marginal adaptation, surface and overfilling.
Objectives: The aim of the study was to determine the time to, and risk factors for, triple-class virological failure (TCVF) across age groups for children and adolescents with perinatally acquired HIV infection and older adolescents and adults with heterosexually acquired HIV infection.
Methods: We analysed individual patient data from cohorts in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE). A total of 5972 participants starting antiretroviral therapy (ART) from 1998, aged < 20 years at the start of ART for those with perinatal infection and 15–29 years for those with heterosexual infection, with ART containing at least two nucleoside reverse transcriptase inhibitors (NRTIs) and a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a boosted protease inhibitor (bPI), were followed from ART initiation until the most recent viral load (VL) measurement. Virological failure of a drug was defined as VL > 500 HIV-1 RNA copies/mL despite ≥ 4 months of use. TCVF was defined as cumulative failure of two NRTIs, an NNRTI and a bPI.
Results: The median number of weeks between diagnosis and the start of ART was higher in participants with perinatal HIV infection compared with participants with heterosexually acquired HIV infection overall [17 (interquartile range (IQR) 4–111) vs. 8 (IQR 2–38) weeks, respectively], and highest in perinatally infected participants aged 10–14 years [49 (IQR 9–267) weeks]. The cumulative proportion with TCVF 5 years after starting ART was 9.6% [95% confidence interval (CI) 7.0−12.3%] in participants with perinatally acquired infection and 4.7% (95% CI 3.9−5.5%) in participants with heterosexually acquired infection, and highest in perinatally infected participants aged 10–14 years when starting ART (27.7%; 95% CI 13.2−42.1%). Across all participants, significant predictors of TCVF were those with perinatal HIV aged 10–14 years, African origin, pre-ART AIDS, NNRTI-based initial regimens, higher pre-ART viral load and lower pre-ART CD4.
Conclusions: The results suggest a beneficial effect of starting ART before adolescence, and starting young people on boosted PIs, to maximize treatment response during this transitional stage of development.
Background: Clonidine effectively decreases perioperative mortality by reducing sympathetic tone. However, application of clonidine might also restrict anaemia tolerance due to impairment of compensatory mechanisms. Therefore, the influence of clonidine induced, short-term sympathicolysis on anaemia tolerance was assessed in anaesthetized pigs. We measured the effect of clonidine on anaemia tolerance and of the potential for macrohemodynamic alterations to constrain the acute anaemia compensatory mechanisms.
Methods: After governmental approval, 14 anaesthetized pigs of either gender (Deutsche Landrasse, weight (mean ± SD) 24.1 ± 2.4 kg) were randomly assigned to intravenous saline or clonidine treatment (bolus: 20 μg · kg−1, continuous infusion: 15 μg · kg−1 · h−1). Thereafter, the animals were hemodiluted by exchange of whole blood for 6 % hydroxyethyl starch (MW 130.000/0.4) until the individual critical haemoglobin concentration (Hbcrit) was reached. Primary outcome parameters were Hbcrit and the exchangeable blood volume (EBV) until Hbcrit was reached.
Results: Hbcrit did not differ between both groups (values are median [interquartile range]: saline: 2.2 (2.0–2.5) g · dL−1 vs. clonidine: 2.1 (2.1–2.4) g · dL−1; n.s.). Furthermore, there was no difference in exchangeable blood volume (EBV) between both groups (saline: 88 (76–106) mL · kg−1 vs. clonidine: 92 (85–95) mL · kg−1; n.s.).
Conclusion: Anaemia tolerance was not affected by clonidine induced sympathicolysis. Consequently, perioperative clonidine administration probably has not to be omitted in view of acute anaemia.
Abstract
Indoor air pollution with harmful particulate matter (PM) is mainly caused by cigarette smoke. Super-Slim-Size-Cigarettes (SSL) are considered a less harmful alternative to King-Size-Cigarettes (KSC) due to longer filters and relatively low contents. We ask if “Combined Mainstream and Sidestream Smoke” (CMSS)-associated PM levels of SSL are lower than of KSC and thus are potentially less harmful. PM concentrations in CMSS (PM10, PM2.5, and PM1) are measured from four cigarette types of the brand Vogue, using an “automatic-environmental-tobacco-smoke-emitter” (AETSE) and laser aerosol spectrometry: SSL-BLEUE, -MENTHE, -LILAS and KSC-La Cigarette and -3R4F reference. This analysis shows that SSL MENTHE emitted the highest amount of PM, and KSC-La Cigarette the lowest. 3R4F reference emitted PM in the middle range, exceeding SSL BLEUE and falling slightly below SSL LILAS. It emerged that PM1 constituted the biggest proportion of PM emission. The outcome shows significant type-specific differences for emitted PM concentrations. Our results indicate that SSL are potentially more harmful for passive smokers than the respective KSC. However, this study cannot give precise statements about the general influence of the size of a cigarette on PM. Alarming is that PM1 is responsible for the biggest proportion of PM pollution, since smaller particles cause more harmful effects.
Background: Although noise is one of the leading work-related health risk factors for teachers, many nursery schools lack sufficient noise reduction measures. Methods: This intervention study evaluated the noise exposure of nursery school teachers when dropping DUPLO toy bricks into storage cases. Sound analyses of the impact included assessment of the maximum sound pressure level (LAFmax) as well as frequency analyses with 1/3 octave band filter. For the purpose of standardization, a customized gadget was developed. Recordings were performed in 11 cases of different materials and designs to assess the impact on sound level reduction. Thereby, the acoustic effects of three damping materials (foam rubber, carpet, and PU-foam) were investigated. Results: The lowest LAFmax was measured in cases consisting of “metal grid” (90.71 dB) or of a woven willow “basket” (91.61 dB), whereas a case of “aluminium” (103.34 dB) generated the highest impact LAFmax. The frequency analyses determined especially low LAFmax in the frequency bands between 80 and 2500 Hz in cases designs “metal grid” and “basket”. The insertion of PU-foam achieved the most significant attenuation of LAFmax (−13.88 dB) and, in the frequency analyses, the best sound damping. Conclusion: The dropping of DUPLO bricks in cases contributes to the high noise level in nursery schools, but measured LAFmax show no evidence for the danger of acute hearing loss. However, continuous exposure may lead to functional impairment of the hair cells and trigger stress reactions. We recommend noise reduction by utilizing cases of woven “basket” with an insert of PU-foam.
Isolated generalized dystonia is a central motor network disorder characterized by twisted movements or postures. The most frequent genetic cause is a GAG deletion in the Tor1a (DYT1) gene encoding torsinA with a reduced penetrance of 30-40 % suggesting additional genetic or environmental modifiers. Development of dystonia-like movements after a standardized peripheral nerve crush lesion in wild type (wt) and Tor1a+/- mice, that express 50 % torsinA only, was assessed by scoring of hindlimb movements during tail suspension, by rotarod testing and by computer-assisted gait analysis. Western blot analysis was performed for dopamine transporter (DAT), D1 and D2 receptors from striatal and quantitative RT-PCR analysis for DAT from midbrain dissections. Autoradiography was used to assess the functional DAT binding in striatum. Striatal dopamine and its metabolites were analyzed by high performance liquid chromatography. After nerve crush injury, we found abnormal posturing in the lesioned hindlimb of both mutant and wt mice indicating the profound influence of the nerve lesion (15x vs. 12x relative to control) resembling human peripheral pseudodystonia. In mutant mice the phenotypic abnormalities were increased by about 40 % (p < 0.05). This was accompanied by complex alterations of striatal dopamine homeostasis. Pharmacological blockade of dopamine synthesis reduced severity of dystonia-like movements, whereas treatment with L-Dopa aggravated these but only in mutant mice suggesting a DYT1 related central component relevant to the development of abnormal involuntary movements. Our findings suggest that upon peripheral nerve injury reduced torsinA concentration and environmental stressors may act in concert in causing the central motor network dysfunction of DYT1 dystonia.
Philadelphia-like B-cell precursor acute lymphoblastic leukemia (Ph-like ALL) is characterized by distinct genetic alterations and inferior prognosis in children and younger adults. The purpose of this study was a genetic and clinical characterization of Ph-like ALL in adults. Twenty-six (13%) of 207 adult patients (median age: 42 years) with B-cell precursor ALL (BCP-ALL) were classified as having Ph-like ALL using gene expression profiling. The frequency of Ph-like ALL was 27% among 95 BCP-ALL patients negative for BCR-ABL1 and KMT2A-rearrangements. IGH-CRLF2 rearrangements (6/16; P=0.002) and mutations in JAK2 (7/16; P<0.001) were found exclusively in the Ph-like ALL subgroup. Clinical and outcome analyses were restricted to patients treated in German Multicenter Study Group for Adult ALL (GMALL) trials 06/99 and 07/03 (n=107). The complete remission rate was 100% among both Ph-like ALL patients (n=19) and the “remaining BCP-ALL” cases (n=40), i.e. patients negative for BCR-ABL1 and KMT2A-rearrangements and the Ph-like subtype. Significantly fewer Ph-like ALL patients reached molecular complete remission (33% versus 79%; P=0.02) and had a lower probability of continuous complete remission (26% versus 60%; P=0.03) and overall survival (22% versus 64%; P=0.006) at 5 years compared to the remaining BCP-ALL patients. The profile of genetic lesions in adults with Ph-like ALL, including older adults, resembles that of pediatric Ph-like ALL and differs from the profile in the remaining BCP-ALL. Our study is the first to demonstrate that Ph-like ALL is associated with inferior outcomes in intensively treated older adult patients. Ph-like adult ALL should be recognized as a distinct, high-risk entity and further research on improved diagnostic and therapeutic approaches is needed.
Cyclic GMP-dependent protein kinase 1 (PKG1) mediates presynaptic nociceptive long-term potentiation (LTP) in the spinal cord and contributes to inflammatory pain in rodents but the present study revealed opposite effects in the context of neuropathic pain. We used a set of loss-of-function models for in vivo and in vitro studies to address this controversy: peripheral neuron specific deletion (SNS-PKG1-/-), inducible deletion in subsets of neurons (SLICK-PKG1-/-) and redox-dead PKG1 mutants. In contrast to inflammatory pain, SNS-PKG1-/- mice developed stronger neuropathic hyperalgesia associated with an impairment of nerve regeneration, suggesting specific repair functions of PKG1. Although PKG1 accumulated at the site of injury, its activity was lost in the proximal nerve due to a reduction of oxidation-dependent dimerization, which was a consequence of mitochondrial damage in injured axons. In vitro, PKG1 deficiency or its redox-insensitivity resulted in enhanced outgrowth and reduction of growth cone collapse in response to redox signals, which presented as oxidative hotspots in growing cones. At the molecular level, PKG1 deficiency caused a depletion of phosphorylated cofilin, which is essential for growth cone collapse and guidance. Hence, redox-mediated guidance required PKG1 and consequently, its deficiency in vivo resulted in defective repair and enhanced neuropathic pain after nerve injury. PKG1-dependent repair functions will outweigh its signaling functions in spinal nociceptive LTP, so that inhibition of PKG1 is no option for neuropathic pain.
Background: Archaeal membranes have phytanyl ether lipids instead of common fatty acid-glycerol esters in bacterial and eukaryotic cells. Sulfolobus and Thermoplasma species have unique membrane-spanning tetraether lipids (TEL), which form stable liposomes. Recently, we cultured Thermoplasma species from the Indonesian volcano Tangkuban Perahu and isolated TEL. The purpose of this in vitro study is to investigate the transfer of fluorescent dye from stable TEL liposomes to cultured colon carcinoma cells.
Methods: TEL was extracted from cultured cells with chloroform-methanol (1:1), then it was fractionated and purified via diethylaminoethyl-cellulose-acetate columns and activated charcoal for the formation of stable liposomes. For the fluorescence exchange assay, TEL liposomes were loaded with water-soluble carboxyfluorescein (CF). Staining experiments were conducted with various cell cultures, and T84 colon carcinoma cells were chosen for the main experiments. Liposome stability was tested by light scattering and electron microscopic size determinations as well as by unspecific CF release at low pH (6.0–7.4) and increased temperature (4–50°C/70°C).
Results: TEL liposomes exhibit high stability and extremely low proton permeability at low pH. CF staining of cultured T84 colon carcinoma cells appeares more intensive from TEL liposomes than from dipalmitoylphosphatidylcholine liposomes.
Conclusion: The results of this in vitro study demonstrate CF staining of colon carcinoma cells and high stability of TEL liposomes at low pH, matching the condition in the gastro-intestinal (GI) route and in the urogentital (UG) tract. For this reason, in vivo studies on liposomal fluorescent photosensitizers for topical application of photodynamic cancer therapy in the GI and UG tracts should be carried out.
The free radical theory of aging suggests reactive oxygen species as a main reason for accumulation of damage events eventually leading to aging. Nox4, a member of the family of NADPH oxidases constitutively produces ROS and therefore has the potential to be a main driver of aging. Herein we analyzed the life span of Nox4 deficient mice and found no difference when compared to their wildtype littermates. Accordingly neither Tert expression nor telomere length was different in cells isolated from those animals. In fact, Nox4 mRNA expression in lungs of wildtype mice dropped with age. We conclude that Nox4 has no influence on lifespan of healthy mice.
Longitudinal changes of cortical microstructure in Parkinson's disease assessed with T1 relaxometry
(2016)
Background: Histological evidence suggests that pathology in Parkinson's disease (PD) goes beyond nigrostriatal degeneration and also affects the cerebral cortex. Quantitative MRI (qMRI) techniques allow the assessment of changes in brain tissue composition. However, the development and pattern of disease-related cortical changes have not yet been demonstrated in PD with qMRI methods. The aim of this study was to investigate longitudinal cortical microstructural changes in PD with quantitative T1 relaxometry.
Methods: 13 patients with mild to moderate PD and 20 matched healthy subjects underwent high resolution T1 mapping at two time points with an interval of 6.4 years (healthy subjects: 6.5 years). Data from two healthy subjects had to be excluded due to MRI artifacts. Surface-based analysis of cortical T1 values was performed with the FreeSurfer toolbox.
Results: In PD patients, a widespread decrease of cortical T1 was detected during follow-up which affected large parts of the temporo-parietal and occipital cortices and also frontal areas. In contrast, age-related T1 decrease in the healthy control group was much less pronounced and only found in lateral frontal, parietal and temporal areas. Average cortical T1 values did not differ between the groups at baseline (p = 0.17), but were reduced in patients at follow-up (p = 0.0004). Annualized relative changes of cortical T1 were higher in patients vs. healthy subjects (patients: − 0.72 ± 0.64%/year; healthy subjects: − 0.17 ± 0.41%/year, p = 0.007).
Conclusions: In patients with PD, the development of widespread changes in cortical microstructure was observed as reflected by a reduction of cortical T1. The pattern of T1 decrease in PD patients exceeded the normal T1 decrease as found in physiological aging and showed considerable overlap with the pattern of cortical thinning demonstrated in previous PD studies. Therefore, cortical T1 might be a promising additional imaging marker for future longitudinal PD studies. The biological mechanisms underlying cortical T1 reductions remain to be further elucidated.