Medizin
Refine
Year of publication
- 2019 (496) (remove)
Document Type
- Article (470)
- Doctoral Thesis (9)
- Part of Periodical (8)
- Book (4)
- Contribution to a Periodical (3)
- Preprint (2)
Has Fulltext
- yes (496)
Is part of the Bibliography
- no (496)
Keywords
- inflammation (10)
- glioblastoma (8)
- cancer (7)
- Breast cancer (6)
- biomarker (6)
- Inflammation (5)
- breast cancer (5)
- immunotherapy (5)
- mTOR (5)
- Biomarkers (4)
Institute
- Medizin (496)
- Sonderforschungsbereiche / Forschungskollegs (22)
- Präsidium (20)
- Biowissenschaften (14)
- Exzellenzcluster Makromolekulare Komplexe (9)
- Exzellenzcluster Herz-Lungen-System (8)
- Biochemie und Chemie (6)
- Georg-Speyer-Haus (5)
- Frankfurt Institute for Advanced Studies (FIAS) (4)
- Pharmazie (4)
Chordomas are rare bone tumors with few therapeutic options. Here we show, using whole-exome and genome sequencing within a precision oncology program, that advanced chordomas (n = 11) may be characterized by genomic patterns indicative of defective homologous recombination (HR) DNA repair and alterations affecting HR-related genes, including, for example, deletions and pathogenic germline variants of BRCA2, NBN, and CHEK2. A mutational signature associated with HR deficiency was significantly enriched in 72.7% of samples and co-occurred with genomic instability. The poly(ADP-ribose) polymerase (PARP) inhibitor olaparib, which is preferentially toxic to HR-incompetent cells, led to prolonged clinical benefit in a patient with refractory chordoma, and whole-genome analysis at progression revealed a PARP1 p.T910A mutation predicted to disrupt the autoinhibitory PARP1 helical domain. These findings uncover a therapeutic opportunity in chordoma that warrants further exploration, and provide insight into the mechanisms underlying PARP inhibitor resistance.
Background: To evaluate the current indications, resection strategies and short-term outcomes of surgery for benign goitre in a country with endemic goitre. Methods: Data of patients who underwent surgery for benign goitre were retrieved from the prospective StuDoQ/Thyroid registry and retrospectively analysed regarding the patient’s demographics, indications for surgery, surgical procedures, histology, and perioperative outcomes. Results: In a 15-month period, 12,888 patients from 83 departments underwent thyroid resections for benign conditions. Main indications for surgery were exclusion of malignancy (68%), compression symptoms (20.7%) and hyperthyroidism (9.7%). Preoperative fine needle aspiration cytology was performed in only 12.2% of patients with the indication "exclusion of malignancy". Thyroidectomy (49.8%) or hemithyroidectomy (36.9%) were performed in 86.7% of patients. Minimally invasive or alternative surgical techniques were applied in only 2.2%. Intraoperative neuromonitoring was used in 98.4% of procedures, in 97.5% of patients at least one parathyroid gland was visualized, and in 15.3% of patients parathyroid tissue was autografted, respectively. The rates of unilateral and bilateral transient recurrent nerve palsy were 3.6% and 0.07% of nerves at risk, the rate of transitory hypoparathyroidism was 15.3%. The rates of postoperative bleeding and wound infections requiring reoperation were 1.4% and 0.07%, respectively. Conclusions: The indication "exclusion of malignancy" is made too liberally, and there is a strong attitude to perform complete thyroid resections. Postoperative hypoparathyroidism is the major complication after surgery for benign thyroid disease, thus requiring more awareness.
Apigenin (4′,5,7-trihydroxyflavone) (Api) is an important component of the human diet, being distributed in a wide number of fruits, vegetables and herbs with the most important sources being represented by chamomile, celery, celeriac and parsley. This study was designed for a comprehensive evaluation of Api as an antiproliferative, proapoptotic, antiangiogenic and immunomodulatory phytocompound. In the set experimental conditions, Api presents antiproliferative activity against the A375 human melanoma cell line, a G2/M arrest of the cell cycle and cytotoxic events as revealed by the lactate dehydrogenase release. Caspase 3 activity was inversely proportional to the Api tested doses, namely 30 μM and 60 μM. Phenomena of early apoptosis, late apoptosis and necrosis following incubation with Api were detected by Annexin V-PI double staining. The flavone interfered with the mitochondrial respiration by modulating both glycolytic and mitochondrial pathways for ATP production. The metabolic activity of human dendritic cells (DCs) under LPS-activation was clearly attenuated by stimulation with high concentrations of Api. Il-6 and IL-10 secretion was almost completely blocked while TNF alpha secretion was reduced by about 60%. Api elicited antiangiogenic properties in a dose-dependent manner. Both concentrations of Api influenced tumour cell growth and migration, inducing a limited tumour area inside the application ring, associated with a low number of capillaries.
Latent tuberculosis infection (LTBI) is established in over 90% of persons infected with Mycobacterium tuberculosis (Mtb), from whom new active TB cases will arise. Understanding the spatio-temporal dynamics of host immune responses in LTBI granulomas is essential to designing effective post-exposure therapies that inhibit progression to TB. Information arising from cancer studies and other modalities – where local chronic inflammation leads to immunopathology – can help provide insights into the biological pathways at play in LTBI granulomas. Translational studies using patient material as well as LTBI+ donor-derived tissue samples are instrumental in understanding the various components of granuloma dynamics, immunological landscapes therein and how this could help to identify therapeutic targets. Deep sequencing technologies may aid to decipher the genetic changes in lung granuloma and blood samples from LTBI+ individuals associated with progression to active TB disease. This may lead to advancement of development of targeted Host-Directed Therapies (HDTs) and their evaluation as adjunct TB therapies for improving treatment outcomes for LTBI and pulmonary TB.
Introduction: Balanced fluid replacement solutions can possibly reduce the risks for electrolyte imbalances, for acid-base imbalances, and thus for renal failure. To assess the intraoperative change of base excess (BE) and chloride in serum after treatment with either a balanced gelatine/electrolyte solution or a non-balanced gelatine/electrolyte solution, a prospective, controlled, randomized, double-blind, dual centre phase III study was conducted in two tertiary care university hospitals in Germany.
Material and methods: 40 patients of both sexes, aged 18 to 90 years, who were scheduled to undergo elective abdominal surgery with assumed intraoperative volume requirement of at least 15 mL/kg body weight gelatine solution were included. Administration of study drug was performed intravenously according to patients need. The trigger for volume replacement was a central venous pressure (CVP) minus positive end-expiratory pressure (PEEP) <10 mmHg (CVP <10 mmHg). The crystalloid:colloid ratio was 1:1 intra- and postoperatively. The targets for volume replacement were a CVP between 10 and 14 mmHg minus PEEP after treatment with vasoactive agent and mean arterial pressure (MAP) > 65 mmHg.
Results: The primary endpoints, intraoperative changes of base excess –2.59 ± 2.25 (median: –2.65) mmol/L (balanced group) and –4.79 ± 2.38 (median: –4.70) mmol/L (non-balanced group)) or serum chloride 2.4 ± 1.9 (median: 3.0) mmol/L and 5.2 ± 3.1 (median: 5.0) mmol/L were significantly different (p = 0.0117 and p = 0.0045, respectively). In both groups (each n = 20) the investigational product administration in terms of volume and infusion rate was comparable throughout the course of the study, i.e. before, during and after surgery.
Discussion: Balanced gelatine solution 4% combined with a balanced electrolyte solution demonstrated significant smaller impact on blood gas analytic parameters in the primary endpoints BE and serum chloride when compared to a non-balanced gelatine solution 4% combined with NaCl 0.9%. No marked treatment differences were observed with respect to haemodynamics, coagulation and renal function.
Trial registration: ClinicalTrials.gov (NCT01515397) and clinicaltrialsregister.eu, EudraCT number 2010-018524-58.
Epigenetic control of the angiotensin-converting enzyme in endothelial cells during inflammation
(2019)
The angiotensin-converting enzyme (ACE) plays a central role in the renin-angiotensin system, which is involved in the regulation of blood pressure. Alterations in ACE expression or activity are associated with various pathological phenotypes, particularly cardiovascular diseases. In human endothelial cells, ACE was shown to be negatively regulated by tumor necrosis factor (TNF) α. To examine, whether or not, epigenetic factors were involved in ACE expression regulation, methylated DNA immunoprecipitation and RNA interference experiments directed against regulators of DNA methylation homeostasis i.e., DNA methyltransferases (DNMTs) and ten-eleven translocation methylcytosine dioxygenases (TETs), were performed. TNFα stimulation enhanced DNA methylation in two distinct regions within the ACE promoter via a mechanism linked to DNMT3a and DNMT3b, but not to DNMT1. At the same time, TET1 protein expression was downregulated. In addition, DNA methylation decreased the binding affinity of the transcription factor MYC associated factor X to the ACE promoter. In conclusion, DNA methylation determines the TNFα-dependent regulation of ACE gene transcription and thus protein expression in human endothelial cells.
Multidrug-resistant TB (MDR-TB) is a major threat to global health security. In 2017, only 50% of patients with MDR-TB who received WHO-recommended treatment were cured. Most MDR-TB patients who recover continue to suffer from functional disability due to long-term lung damage. Whilst new MDR-TB treatment regimens are becoming available, conventional drug therapies need to be complemented with host-directed therapies (HDTs) to reduce tissue damage and improve functional treatment outcomes. This viewpoint highlights recent data on biomarkers, immune cells, circulating effector molecules and genetics which could be utilised for developing personalised HDTs. Novel technologies currently used for cancer therapy which could facilitate in-depth understanding of host genetics and the microbiome in patients with MDR-TB are discussed. Against this background, personalised cell-based HDTs for adjunct MDR-TB treatment to improve clinical outcomes are proposed as a possibility for complementing standard therapy and other HDT agents. Insights into the molecular biology of the mechanisms of action of cellular HDTs may also aid to devise non-cell-based therapies targeting defined inflammatory pathway(s) in Mtb-driven immunopathology.
A body of research demonstrates convincingly a role for synchronization of auditory cortex to rhythmic structure in sounds including speech and music. Some studies hypothesize that an oscillator in auditory cortex could underlie important temporal processes such as segmentation and prediction. An important critique of these findings raises the plausible concern that what is measured is perhaps not an oscillator but is instead a sequence of evoked responses. The two distinct mechanisms could look very similar in the case of rhythmic input, but an oscillator might better provide the computational roles mentioned above (i.e., segmentation and prediction). We advance an approach to adjudicate between the two models: analyzing the phase lag between stimulus and neural signal across different stimulation rates. We ran numerical simulations of evoked and oscillatory computational models, showing that in the evoked case,phase lag is heavily rate-dependent, while the oscillatory model displays marked phase concentration across stimulation rates. Next, we compared these model predictions with magnetoencephalography data recorded while participants listened to music of varying note rates. Our results show that the phase concentration of the experimental data is more in line with the oscillatory model than with the evoked model. This finding supports an auditory cortical signal that (i) contains components of both bottom-up evoked responses and internal oscillatory synchronization whose strengths are weighted by their appropriateness for particular stimulus types and (ii) cannot be explained by evoked responses alone.
Background: While ICF-CY-based models of care are promising avenues for improving participation of children with chronic health conditions, feasible and valid instruments to assess participation as an outcome in routine are still needed. We aimed to validate a German parent-report version of the Child and Adolescent Scale of Participation (CASP) in children with chronic health conditions of different severity.
Methods: Cross-sectional data were collected in 327 children (mean age 7.8 years, 55% boys) from two paediatric centres (n = 112) and one population-based sample (n = 215). Cronbach’s alpha, factor analyses, face validity assessments, correlation analyses, receiver operating characteristics (ROC) curves, and parent-reported health-related quality of life (HRQoL: KINDL) were used to examine internal consistency, test-retest reliability, and capacity to differentiate between disease severity groups. Disease severity was operationalized according to ICD-diagnosis groups and/or parent-reports on health problems, medical and educational support, and medication. A newly developed item "overall perceived participation" was added to the CASP and evaluated.
Results: We found good to excellent content validity, excellent internal consistency, and good-to-excellent test-retest reliability of the instrument. While children with mild disease had a significantly greater extent of participation (higher CASP scores) than children with severe disease, they did not differ from healthy children. Children with mild compared to severe disease much more differed in participation as measured by the CASP compared to the KINDL (area under the ROC curve: 0.92 vs. 0.75). In addition, the item "overall perceived participation" was highly correlated (r = 0.86) with the CASP total score, indicating the potential value of this specific single item. Finally, we provided preliminary reference values for the CASP obtained in a population-based sample of children without chronic health conditions.
Conclusions: The German version of the CASP and the new item are efficient, valid and reliable measures of social participation in childhood. The CASP-measured participation focuses more on attendance than on involvement into social circumstances of everyday life. To detect children with a high burden of disease on everyday life, the CASP may be more accurate than HRQoL instruments such as the KINDL. As outcome measurement, the CASP may facilitate the implementation of patient-centred paediatric health care.
Clinically relevant immune responses against Cytomegalovirus : implications for precision medicine
(2019)
Immune responses to human cytomegalovirus (CMV) can be used to assess immune fitness in an individual. Further to its clinical significance in posttransplantation settings, emerging clinical and translational studies provide examples of immune correlates of protection pertaining to anti-CMV immune responses in the context of cancer or infectious diseases, e.g., tuberculosis. In this viewpoint, we provide a brief overview about CMV-directed immune reactivity and immune fitness in a clinical context and incorporate some of our own findings obtained from peripheral blood or tumour-infiltrating lymphocytes (TIL) from patients with advanced cancer. Observations in patients with solid cancers whose lesions contain both CMV and tumour antigen-specific T-cell subsets are highlighted, due to a possible CMV-associated "bystander" effect in amplifying local inflammation and subsequent tumour rejection. The role of tumour-associated antibodies recognising diverse CMV-derived epitopes is also discussed in light of anti-cancer immune responses. We discuss here the use of anti-CMV immune responses as a theranostic tool—combining immunodiagnostics with a personalised therapeutic potential—to improve treatment outcomes in oncological indications.
Background: Oral anticoagulants can cause potentially serious adverse events. Therefore, before prescribing oral anticoagulants for ischemic stroke prevention in patients with atrial fibrillation (AF), stroke risk assessment is required to identify patients that are likely to benefit from treatment. Current guidelines recommend the CHA2DS2-VASc-score for stroke risk assessment. The CHA2DS2-VASc-score is based on observational studies from different treatment settings and countries. As ischemic stroke risk differs by setting and region, the aim of this study is to estimate ischemic stroke risk (stratified by the CHA2DS2-VASc-score) for a broadly representative population with AF from southern Germany and compare them to results from previous studies.
Methods: The study design is a retrospective cohort study on patients with atrial fibrillation based on secondary data. We calculated CHA2DS2-VASc-score based on patient’s diagnoses recorded in the year 2014 and assessed outcomes in 2015–2016. The primary outcome is hospitalization for ischemic stroke. The secondary outome is hospitalizations for any thromboembolic event, including ischemic stroke, transient ischemic attack, peripheral arterial embolism, pulmonary embolism, and mesenterial embolism. We estimated the incidence rates of the outcomes (and corresponding 95%-confidence intervals) stratified by CHA2DS2-VASc-score.
Results: The primary endpoint occurred in 961 of the 30,299 patients constituting the study population, resulting in a total incidence rate of 2.2 per 100 person-years. The secondary endpoint occurred in 1553 patients (3.6 per 100 person-years). Ischemic stroke rates stratified by the CHA2DS2-VASc-score tended to be lower than those reported previously. Thromboembolic event rates stratified tended to be similar to those reported previously.
Conclusions: Our results show that the performance of the CHA2DS2-VASc-score differs in the German population, as compared to internationally published data, with an overall trend towards lower risk of ischemic stroke in uncoagulated patients with AF. These results should not be practice changing, but they emphasize that stroke risk estimation in patients with atrial fibrillation should be further refined.
The mechanistic target of rapamycin (mTOR) is elevated in prostate cancer, making this protein attractive for tumor treatment. Unfortunately, resistance towards mTOR inhibitors develops and the tumor becomes reactivated. We determined whether epigenetic modulation by the histone deacetylase (HDAC) inhibitor, valproic acid (VPA), may counteract non-responsiveness to the mTOR inhibitor, temsirolimus, in prostate cancer (PCa) cells. Prostate cancer cells, sensitive (parental) and resistant to temsirolimus, were exposed to VPA, and tumor cell growth behavior compared. Temsirolimus resistance enhanced the number of tumor cells in the G2/M-phase, correlating with elevated cell proliferation and clonal growth. The cell cycling proteins cdk1 and cyclin B, along with Akt-mTOR signaling increased, whereas p19, p21 and p27 decreased, compared to the parental cells. VPA significantly reduced cell growth and up-regulated the acetylated histones H3 and H4. Cdk1 and cyclin B decreased, as did phosphorylated mTOR and the mTOR sub-complex Raptor. The mTOR sub-member Rictor and phosphorylated Akt increased under VPA. Knockdown of cdk1, cyclin B, or Raptor led to significant cell growth reduction. HDAC inhibition through VPA counteracts temsirolimus resistance, probably by down-regulating cdk1, cyclin B and Raptor. Enhanced Rictor and Akt, however, may represent an undesired feedback loop, which should be considered when designing future therapeutic regimens.
Purpose: To evaluate if repeat Descemet membrane endothelial keratoplasty (DMEK) is appropriate to achieve functional improvements in patients with corneal decompensation from secondary graft failure after primary DMEK.
Methods: This is a retrospective monocentric cohort study including 13 eyes of 13 patients with repeat DMEK for corneal decompensation following primary DMEK. Eyes with primary DMEK only and comparable preoperative corrected distance visual acuity (CDVA) served as control. Main outcome parameter was CDVA. Secondary outcome measures were central corneal thickness (CCT), endothelial cell density, and rebubbling rate (RR).
Results: The average time interval (±SD) between primary and secondary DMEK was 12.5±6 months. Preoperative CDVA (logMAR) was 1.97±0.90 in the repeat DMEK group and 1.38±0.92 in the primary DMEK group. At 6 months, both groups showed significant improvement in visual acuity (repeat DMEK group, 0.49±0.35, P<0.01 and primary DMEK group, 0.40±0.36, P<0.01). CDVA did not differ significantly between both groups at all time points examined (1, 3, and 6 months postoperatively). Mean CCT values at 3 and 6 months postoperatively did not differ significantly between the two groups (P>0.05). The RR was
23% (n=3) in both groups.
Conclusion: Repeat DMEK is a useful therapeutic approach in the setting of corneal decompensation following primary DMEK. Functional results of repeat DMEK, visual acuity in particular, are comparable to patients with single DMEK only.
The treatment of patients with advanced breast cancer has developed further in recent years. In addition to therapeutic progress in the established subgroups (hormone receptor and HER2 status), there are now therapies which are geared to individual molecular characteristics, such as PARP inhibitor therapy in BRCA-mutated patients. In addition to this, tests are being developed which are intended to establish additional markers within subgroups in order to predict the efficacy of a therapy. PI3K mutation testing in HER2-negative, hormone-receptor-positive tumours and PD-L1 testing of immune cells in triple-negative tumours are expected to become established in clinical practice in order to select patients for the respective therapies. With new therapeutic approaches, new adverse effects also appear. The management of these adverse effects, just as those of classical therapy (supportive therapy), is essential with the introduction of new treatments in order to preserve patientsʼ quality of life. Knowledge regarding measures to preserve and improve quality of life has significantly increased in recent years. Lifestyle factors should be taken into account, as should modern therapeutic methods. This review summarises the latest studies and publications and evaluates them in regard to the relevance for clinical practice.
Die Behandlung von Patientinnen mit fortgeschrittenem Mammakarzinom hat sich in den letzten Jahren weiterentwickelt. Zusätzlich zum Therapiefortschritt in den etablierten Subgruppen (Hormonrezeptor- und HER2-Status) gibt es nun Therapien, die sich an einzelnen molekularen Charakteristika orientieren, wie zum Beispiel die PARP-Inhibitortherapie bei BRCA-mutierten Patientinnen. Zusätzlich dazu sind Tests in der Entwicklung, die innerhalb von Subgruppen weitere Marker etablieren sollen, um die Wirksamkeit einer Therapie vorherzusagen. Die PI3K-Mutationstestung bei HER2-negativen, hormonrezeptorpositiven Tumoren, und die PD-L1-Testung von Immunzellen bei triple-negativen Tumoren werden voraussichtlich in der klinischen Praxis etabliert, um Patientinnen für die jeweiligen Therapien auszuwählen. Mit neuen Therapieansätzen treten auch neue Nebenwirkungen auf. Das Management dieser Nebenwirkungen ebenso wie die der klassischen Therapien (supportive Therapie) ist mit der Einführung neuer Behandlungen essenziell, um die Lebensqualität der Patientinnen zu erhalten. Das Wissen über Maßnahmen zur Erhaltung und Verbesserung der Lebensqualität hat in den letzten Jahren deutlich zugenommen. Lifestyle-Faktoren sollten dabei ebenso Berücksichtigung finden wie moderne Therapieverfahren. Diese Übersichtsarbeit fasst die neuesten Studien und Veröffentlichungen zusammen und bewertet sie in Bezug auf die Relevanz für die klinische Praxis.
For many years, small but significant advancements have been made time and again in the prevention and treatment of early breast cancer. The so-called panel gene analyses are becoming more and more important in prevention, since the risk due to the tested genes is better understood and as a result, concepts for integration in health care can be developed. In the adjuvant situation, the first study in the so-called post-neoadjuvant situation was able to demonstrate a clear improvement in the prognosis with an absent pathological complete remission following trastuzumab or pertuzumab + trastuzumab. Additional studies with this post-neoadjuvant therapeutic concept are still being conducted at present. The CDK4/6 inhibitors which had shown a significant improvement in progression-free survival in a metastatic situation are currently being tested in the adjuvant situation in large therapeutic studies. These and other new data for the treatment or prevention of primary breast cancer are presented in this review against the backdrop of current studies.
In der Prävention und Behandlung des frühen Mammakarzinoms sind über die Jahre immer wieder kleine, aber bedeutsame Fortschritte gemacht worden. In der Prävention gewinnen die sogenannten Panel-Gen-Analysen immer mehr an Bedeutung, da das durch die getesteten Gene bedingte Risiko immer besser verstanden wird und somit Konzepte für die Integration in die Krankenversorgung erarbeitet werden können. In der adjuvanten Situation konnte die erste Studie in der sogenannten postneoadjuvanten Situation bei fehlender pathologischer Komplettremission nach Trastuzumab oder Pertuzumab + Trastuzumab eine deutliche Verbesserung der Prognose zeigen. Weitere Studien mit diesem postneoadjuvanten Therapiekonzept werden zurzeit noch durchgeführt. Die CDK4/6-Inhibitoren, die in der metastasierten Situation eine deutliche Verbesserung des progressionsfreien Überlebens gezeigt hatten, werden zurzeit in der adjuvanten Situation in großen Therapiestudien getestet. Diese und weitere neue Daten zur Behandlung oder Prävention des primären Mammakarzinoms werden in dieser Übersichtsarbeit vor dem Hintergrund aktueller Studien vorgestellt.
The circumventricular organs (CVOs) in the central nervous system (CNS) lack a vascular blood-brain barrier (BBB), creating communication sites for sensory or secretory neurons, involved in body homeostasis. Wnt/β-catenin signaling is essential for BBB development and maintenance in endothelial cells (ECs) in most CNS vessels. Here we show that in mouse development, as well as in adult mouse and zebrafish, CVO ECs rendered Wnt-reporter negative, suggesting low level pathway activity. Characterization of the subfornical organ (SFO) vasculature revealed heterogenous claudin-5 (Cldn5) and Plvap/Meca32 expression indicative for tight and leaky vessels, respectively. Dominant, EC-specific β-catenin transcription in mice, converted phenotypically leaky into BBB-like vessels, by augmenting Cldn5+ vessels, stabilizing junctions and by reducing Plvap/Meca32+ and fenestrated vessels, resulting in decreased tracer permeability. Endothelial tightening augmented neuronal activity in the SFO of water restricted mice. Hence, regulating the SFO vessel barrier may influence neuronal function in the context of water homeostasis.
Introduction: The Retro-IDEAL (ILUVIEN Implant for chronic DiabEtic MAcuLar edema) study is a retrospective study designed to assess real-world outcomes achieved with the ILUVIEN® (0.19 mg fluocinolone acetonide (FAc)) in patients with chronic diabetic macular edema (DME) in clinical practices in Germany.
Methods: This study was conducted across 16 sites in Germany and involved 81 eyes (63 patients) with persistent or recurrent DME and a prior suboptimal response to a first-line intravitreal therapy (primarily anti-VEGF intravitreal therapies).
Results: Patients were followed-up for 30.8 ± 11.3 months (mean ± standard deviation) and had a mean age of 68.0 ± 10.4 years. Best-recorded visual acuity (BRVA) improved by +5.5 letters at month 9 (P ⩽ 0.005, n=56; from a baseline of 49 letters) and this was maintained through to month 30 (P ⩽ 0.05, n = 42). There was a concurrent improvement in central macular thickness with a reduction from 502 µm at baseline to 338 µm at year 1 (P ⩽ 0.0001, n = 43). This effect was sustained to year 3 (i.e. 318 µm; P ⩽ 0.0001, n = 29). Mean intraocular pressure (IOP) remained constant between baseline and year 3 with a peak change of 1.9 mm Hg occurring at year 1. Elevated IOP was observed in a similar percentage of patients prior to (22.2% of cases) and following (27.2%) treatment with the FAc implant. In the majority of cases, these elevations were managed effectively with IOP medications.
Conclusions: Despite substantial amounts of prior intravitreal treatments – primarily with anti–vascular endothelial growth factor (VEGF) drugs – this real-world study showed that sustained structural and functional improvements can last for up to 3 years with a single FAc implant.
BIAM switch assay coupled to mass spectrometry identifies novel redox targets of NADPH oxidase 4
(2019)
Aim: NADPH oxidase (Nox) -derived reactive oxygen species have been implicated in redox signaling via cysteine oxidation in target proteins. Although the importance of oxidation of target proteins is well known, the specificity of such events is often debated. Only a limited number of Nox-oxidized proteins have been identified thus far; especially little is known concerning redox-targets of the constitutively active NADPH oxidase Nox4.
In this study, HEK293 cells with tetracycline-inducible Nox4 overexpression (HEK-tet-Nox4), as well as podocytes of WT and Nox4-/- mice, were utilized to identify Nox4-dependent redox-modified proteins.
Results: TGFβ1 induced an elevation in Nox4 expression in podocytes from WT but not Nox4-/- mice. Using BIAM based redox switch assay in combination with mass spectrometry and western blot analysis, 142 proteins were identified as differentially oxidized in podocytes from wild type vs. Nox4-/- mice and 131 proteins were differentially oxidized in HEK-tet-Nox4 cells upon Nox4 overexpression. A predominant overlap was found for peroxiredoxins and thioredoxins, as expected. More interestingly, the GRB2-associated-binding protein 1 (Gab1) was identified as being differentially oxidized in both approaches. Further analysis using mass spectrometry-coupled BIAM switch assay and site directed mutagenesis, revealed Cys374 and Cys405 as the major Nox4 targeted oxidation sites in Gab1.
Innovation & conclusion: BIAM switch assay coupled to mass spectrometry is a powerful and versatile tool to identify differentially oxidized proteins in a global untargeted way. Nox4, as a source of hydrogen peroxide, changes the redox-state of numerous proteins. Of those, we identified Gab1 as a novel redox target of Nox4.