RepoMed (Medizinische Hochschule Hannover)
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COVID-19 in lung transplant recipients-Risk prediction and outcomes.
No full textPatients after lung transplantation are at risk for life-threatening infections. Recently, several publications on COVID-19 outcomes in this patient population appeared, but knowledge on optimal treatment, mortality, outcomes, and appropriate risk predictors is limited. A retrospective analysis was performed in a German high-volume lung transplant center between 19th March 2020 and 18th May 2021. Impact of COVID-19 on physical and psychological health, clinical outcomes, and mortality were analyzed including follow-up visits up to 12 weeks after infection in survivors. Predictive parameters on survival were assessed using univariate and multivariate proportional hazards regression models. Out of 1,046 patients in follow-up, 31 acquired COVID-19 during the pandemic. 12 of 31 (39%) died and 26 (84%) were hospitalized. In survivors a significant decline in exercise capacity (p = 0.034), TLC (p = 0.02), and DLCO (p = 0.007) was observed at follow-up after 3 months. Anxiety, depression, and self-assessed quality of life remained stable. Charlson comorbidity index predicted mortality (HR 1.5, 1.1-2.2; p = 0.023). In recipients with pre-existing CLAD, mortality and clinical outcomes were inferior. However, pre-existing CLAD did not predict mortality. COVID-19 remains a life-threatening disease for lung transplant recipients, particularly in case comorbidities. Further studies on long term outcomes and impact on pre-existing CLAD are needed
Offene versus arthroskopische Latarjet-Operation: Bestimmung der Genauigkeit der Korakoidplatzierung mittels einer Studie an humanen Leichen
No full textImproved Activity against Acute Myeloid Leukemia with Chimeric Antigen Receptor (CAR)-NK-92 Cells Designed to Target CD123.
No full textAnti-cancer activity can be improved by engineering immune cells to express chimeric antigen receptors (CARs) that recognize tumor-associated antigens. Retroviral vector gene transfer strategies allow stable and durable transgene expression. Here, we used alpharetroviral vectors to modify NK-92 cells, a natural killer cell line, with a third-generation CAR designed to target the IL-3 receptor subunit alpha (CD123), which is strongly expressed on the surface of acute myeloid leukemia (AML) cells. Alpharetroviral vectors also contained a transgene cassette to allow constitutive expression of human IL-15 for increased NK cell persistence in vivo. The anti-AML activity of CAR-NK-92 cells was tested via in vitro cytotoxicity assays with the CD123+ AML cell line KG-1a and in vivo in a patient-derived xenotransplantation CD123+ AML model. Unmodified NK-92 cells or NK-92 cells modified with a truncated version of the CAR that lacked the signaling domain served as controls. Alpharetroviral vector-modified NK-92 cells stably expressed the transgenes and secreted IL-15. Anti-CD123-CAR-NK-92 cells exhibited enhanced anti-AML activity in vitro and in vivo as compared to control NK-92 cells. Our data (1) shows the importance of IL-15 expression for in vivo persistence of NK-92 cells, (2) supports continued investigation of anti-CD123-CAR-NK cells to target AML, and (3) points towards potential strategies to further improve CAR-NK anti-AML activity
Elevated insulin biosynthesis and folding in the initial course of type 2 diabetes causing β-cell damage by luminal H2O2 generation and oxidative ER stress
No full textIdentification of Impaired Executive Functioning after Pediatric Liver Transplantation Using Two Short and Easily Applicable Tests: Cognitive Functioning Module PedsQL and Children's Color Trail Test.
No full textWe aimed to assess executive functioning in children after liver transplantation compared with healthy controls and in relation to real-life school performance using the PedsQLTM Cognitive Functioning Scale (CogPedsQL) and the Childrens' Color Trail Test (CCTT). One hundred and fifty five children (78f, median age 10.4 (1.2-18.3) years) underwent testing with CogPedsQL and/or CCTT 4.9 (0.1-17.0) years after transplantation. Results were compared to those of 296 healthy children (165f, median age 10.0 (2.0-18.0) years). Liver transplanted children displayed significantly reduced scores for cogPedsQL and CCTT1&2 compared to healthy controls. Overall, school performance was lower in patients compared to controls. In both patients and controls, results of CCTT2 and CogPedsQL correlated strongly with school performance. In contrast to controls, school performance in patients correlated with the level of maternal but not paternal primary education degree (r = -0.21, p = 0.03). None of the patient CCTT or CogPedsQL test results correlated with parental school education. Conclusion: CogPedsQL and CCTT 1&2 were easily applicable in children after OLT and revealed reduced executive functioning compared to controls. Results reflect real life school performance. The association of parental education with school performance is reduced in transplanted children, which possibly indicates the overriding impact of transplant-associated morbidity on cognitive outcomes
Performance of Calcium Phosphate Cements in the Augmentation of Sheep Vertebrae: An Ex Vivo Study
No full textOil-based calcium phosphate cement (Paste-CPC) shows not only prolonged shelf life and injection times, but also improved cohesion and reproducibility during application, while retaining the advantages of fast setting, mechanical strength, and biocompatibility. In addition, poly(L-lactide-co-glycolide) (PLGA) fiber reinforcement may decrease the risk for local extrusion. Bone defects (diameter 5 mm; depth 15 mm) generated ex vivo in lumbar (L) spines of female Merino sheep (2-4 years) were augmented using: (i) water-based CPC with 10% PLGA fiber reinforcement (L3); (ii) Paste-CPC (L4); or (iii) clinically established polymethylmethacrylate (PMMA) bone cement (L5). Untouched (L1) and empty vertebrae (L2) served as controls. Cement performance was analyzed using micro-computed tomography, histology, and biomechanical testing. Extrusion was comparable for Paste-CPC(-PLGA) and PMMA, but significantly lower for CPC + PLGA. Compressive strength and Young's modulus were similar for Paste-CPC and PMMA, but significantly higher compared to those for empty defects and/or CPC + PLGA. Expectedly, all experimental groups showed significantly or numerically lower compressive strength and Young's modulus than those of untouched controls. Ready-to-use Paste-CPC demonstrates a performance similar to that of PMMA, but improved biomechanics compared to those of water-based CPC + PLGA, expanding the therapeutic arsenal for bone defects. O, significantly lower extrusion of CPC + PLGA fibers into adjacent lumbar spongiosa may help to reduce the risk of local extrusion in spinal surgery
Modified Hyaluronic Acid-Laminin-Hydrogel as Luminal Filler for Clinically Approved Hollow Nerve Guides in a Rat Critical Defect Size Model.
No full textHollow nerve guidance conduits are approved for clinical use for defect lengths of up to 3 cm. This is because also in pre-clinical evaluation they are less effective in the support of nerve regeneration over critical defect lengths. Hydrogel luminal fillers are thought to improve the regeneration outcome by providing an optimized matrix inside bioartificial nerve grafts. We evaluated here a modified hyaluronic acid-laminin-hydrogel (M-HAL) as luminal filler for two clinically approved hollow nerve guides. Collagen-based and chitosan-based nerve guides were filled with M-HAL in two different concentrations and the regeneration outcome comprehensively studied in the acute repair rat sciatic nerve 15 mm critical defect size model. Autologous nerve graft (ANG) repair served as gold-standard control. At 120 days post-surgery, all ANG rats demonstrated electrodiagnostically detectable motor recovery. Both concentrations of the hydrogel luminal filler induced improved regeneration outcome over empty nerve guides. However, neither combination with collagen- nor chitosan-based nerve guides resulted in functional recovery comparable to the ANG repair. In contrast to our previous studies, we demonstrate here that M-HAL slightly improved the overall performance of either empty nerve guide type in the critical defect size model
Prospects and Challenges for T Cell-Based Therapies of HCC.
No full textThe scope of therapeutic options for the treatment of hepatocellular carcinoma (HCC) has recently been expanded by immunotherapeutic regimens. T cell-based therapies, especially in combination with other treatments have achieved far better outcomes compared to conventional treatments alone. However, there is an emerging body of evidence that eliciting T cell responses in immunotherapeutic approaches is insufficient for favorable outcomes. Immune responses in HCC are frequently attenuated in the tumor microenvironment (TME) or may even support tumor progress. Hence, therapies with immune checkpoint inhibitors or adoptive cell therapies appear to necessitate additional modification of the TME to unlock their full potential. In this review, we focus on immunotherapeutic strategies, underlying molecular mechanisms of CD8 T cell immunity, and causes of treatment failure in HCC of viral and non-viral origin. Furthermore, we provide an overview of TME features in underlying etiologies of HCC patients that mediate therapy resistance to checkpoint inhibition and discuss strategies from the literature concerning current approaches to these challenges
Efficient Genetic Safety Switches for Future Application of iPSC-Derived Cell Transplants.
No full textInduced pluripotent stem cell (iPSC)-derived cell products hold great promise as a potential cell source in personalized medicine. As concerns about the potential risk of graft-related severe adverse events, such as tumor formation from residual pluripotent cells, currently restrict their applicability, we established an optimized tool for therapeutic intervention that allows drug-controlled, specific and selective ablation of either iPSCs or the whole graft through genetic safety switches. To identify the best working system, different tools for genetic iPSC modification, promoters to express safety switches and different safety switches were combined. Suicide effects were slightly stronger when the suicide gene was delivered through lentiviral (LV) vectors compared to integration into the AAVS1 locus through TALEN technology. An optimized HSV-thymidine kinase and the inducible Caspase 9 both mediated drug-induced, efficient in vitro elimination of transgene-positive iPSCs. Choice of promoter allowed selective elimination of distinct populations within the graft: the hOct4 short response element restricted transgene expression to iPSCs, while the CAGs promoter ubiquitously drove expression in iPSCs and their progeny. Remarkably, both safety switches were able to prevent in vivo teratoma development and even effectively eliminated established teratomas formed by LV CAGs-transgenic iPSCs. These optimized tools to increase safety provide an important step towards clinical application of iPSC-derived transplants
Development of an in vitro assay for the detection of polymerization of the pyrin domain of ASC.
No full textMulticomponent protein complexes called inflammasomes play a major role in the innate immune system by activating proinflammatory cytokines and promoting a highly inflammatory form of programmed cell death, called pyroptosis. A hallmark of the function of the nucleotide-binding domain, leucine-rich repeat and NLRP3-mediated inflammasome assembly is the polymerization of ASC into large filaments. The ASC filaments recruit and activate procaspase-1 by induced proximity. We developed an in vitro assay for monitoring the polymerization of the pyrin domain of ASC by microscale thermophoresis. We have validated the assay by analyzing the effects of buffer conditions, mutations of ASC and the use of seeds on the polymerization behavior of ASC