A chair-stand time of greater than 15 seconds is associated with an increased risk of death and hospitalization in cirrhosis.

Background: Frailty is a clinical state of increased vulnerability and is common in patients with cirrhosis. The liver frailty index (LFI) is a validated tool to evaluate frailty in cirrhosis, comprising of grip strength, chair stands, and balance tests. The chair-stand test is an easy to conduct frailty subcomponent that does not require specialized equipment and may be valuable to predict adverse clinical outcomes in cirrhosis. The objective of this study was to determine if the chair-stand test is an independent predictor of mortality and hospitalization in cirrhosis. Methods: A retrospective review of 787 patients with cirrhosis was conducted. Chair-stand times were collected at baseline in person and divided into three groups: <10 seconds (n = 276), 10-15 seconds (n = 290), and >15 seconds (n = 221). Fine-Gray proportional hazards regression models were used to evaluate the association between chair-stand times and the outcomes of mortality and non-elective hospitalization. Results: The hazard of mortality (HR 3.21, 95% CI 2.16%-4.78%, p <0.001) and non-elective hospitalization (HR 2.24, 95% CI 1.73%-2.91%, p <0.001) was increased in group 3 in comparison to group 1. A chair-stand test time >15 seconds had increased all-cause mortality (HR 2.78, 95% CI 2.01%-3.83%, p <0.001) and non-elective hospitalizations (HR 1.84, 95% CI 1.48%-2.29%, p <0.001) compared to <15 seconds. Conclusions: A chair-stand test time of >15 seconds is independently associated with mortality and non-elective hospitalizations. This test holds promise as a rapid prognostication tool in cirrhosis. Future work will include external validation and virtual assessment in this population.

A systematic review of kidney-on-a-chip-based models to study human renal (patho-)physiology.

As kidney diseases affect ∼10% of the world population, understanding the underlying mechanisms and developing therapeutic interventions are of high importance. Although animal models have enhanced knowledge of disease mechanisms, human (patho-)physiology may not be adequately represented in animals. Developments in microfluidics and renal cell biology have enabled the development of dynamic models to study renal (patho-)physiology in vitro. Allowing inclusion of human cells and combining different organ models, such as kidney-on-a-chip (KoC) models, enable the refinement and reduction of animal experiments. We systematically reviewed the methodological quality, applicability and effectiveness of kidney-based (multi-)organ-on-a-chip models, and describe the state-of-the-art, strengths and limitations, and opportunities regarding basic research and implementation of these models. We conclude that KoC models have evolved to complex models capable of mimicking systemic (patho-)physiological processes. Commercial chips and human induced pluripotent stem cells and organoids are important for KoC models to study disease mechanisms and assess drug effects, even in a personalized manner. This contributes to the Reduction, Refinement and Replacement of animal models for kidney research. A lack of reporting of intra- and inter-laboratory reproducibility and translational capacity currently hampers implementation of these models.

A human kidney and liver organoid-based multi-organ-on-a-chip model to study the therapeutic effects and biodistribution of mesenchymal stromal cell-derived extracellular vesicles.

Mesenchymal stromal cell (MSC)-derived small extracellular vesicles (sEVs) show therapeutic potential in multiple disease models, including kidney injury. Clinical translation of sEVs requires further preclinical and regulatory developments, including elucidation of the biodistribution and mode of action (MoA). Biodistribution can be determined using labelled sEVs in animal models which come with ethical concerns, are time-consuming and expensive, and may not well represent human physiology. We hypothesised that, based on developments in microfluidics and human organoid technology, in vitro multi-organ-on-a-chip (MOC) models allow us to study effects of sEVs in modelled human organs like kidney and liver in a semi-systemic manner. Human kidney- and liver organoids combined by microfluidic channels maintained physiological functions, and a kidney injury model was established using hydrogenperoxide. MSC-sEVs were isolated, and their size, density and potential contamination were analysed. These sEVs stimulated recovery of the renal epithelium after injury. Microscopic analysis shows increased accumulation of PKH67-labelled sEVs not only in injured kidney cells, but also in the unharmed liver organoids, compared to healthy control conditions. In conclusion, this new MOC model recapitulates therapeutic efficacy and biodistribution of MSC-sEVs as observed in animal models. Its human background allows for in-depth analysis of the MoA and identification of potential side effects.

Why Sleep is Key: Poor Sleep Quality is a Mechanism for the Bidirectional Relationship between Major Depressive Disorder and Generalized Anxiety Disorder Across 18 Years.

BACKGROUND: Generalized anxiety disorder (GAD) and major depressive disorder (MDD) reliably precede and predict one another. However, there is insufficient data on mediators through which the longitudinal GAD-MDD association unfold. Based on insomnia theories, such as the hyperarousal model of sleep, we tested the degree to which poor global sleep quality functioned as a mediator of the prospective bidirectional anxiety-depression relationship. METHOD: Participants were 3,294 community-dwelling adults who partook in three measurement waves nine years apart. The Composite International Diagnostic Interview-Short Form assessed GAD and MDD in-person at baseline (Time 1 [T1]), Time 2 (T2; nine years after T1), and 18 years later (T3). T2 global sleep quality was measured using the multiple-domain Pittsburgh Sleep Quality Index self-report at T2. We used longitudinal structural equation modeling mediation analyses. RESULTS: Analyses showed that higher T1 MDD and GAD severity individually predicted lower T2 global sleep quality (Cohen's d = -0.561 to -0.480) and less T2 global sleep quality, thereby forecasted both higher T3 MDD and GAD (d = -0.275 to -0.190). Poorer T2 global sleep quality significantly mediated the T1 GAD-T3 MDD relation, explaining 41% of the association. Worse global sleep quality at T2 also significantly mediated the T1 MDD-T3 GAD association, mediating 11% of the T1 MDD-T3 GAD pathway. The results remained similar after controlling for multiple sociodemographic and clinical variables. CONCLUSIONS: Findings offer evidence for transdiagnostic theories of sleep and insomnia. Theoretical and clinical implications, such as prioritizing sleep improvement in cognitive-behavioral therapies, are also discussed.

Subfertility in young male mice mutant for chromatin remodeller CECR2.

Defects in spermatogenesis are an important cause of male infertility. Multiple aspects of spermatogenesis are controlled by chromatin remodellers, including regulating transcription. We previously described mutations in chromatin remodelling gene Cecr2 that resulted in the lethal neural tube defect exencephaly in most mutant mice and subfertility in mice that were non-penetrant for exencephaly. Here, we show that the severity of male subfertility is dependent on age. Cecr2GT/Del males contain two mutant alleles, one of which is hypomorphic and therefore produces a small amount of protein. These males sire the fewest pups just after sexual maturity (88% fewer than Cecr2+/+ at P42-60) but improve with age (49% fewer than Cecr2+/+ at P81-100), although never completely recovering to Cecr2+/+(wild type) levels. When young, they also have defects in testis histology, in vivo fertilization frequency, sperm number and motility, and testis weight that show similar improvement with age. Immunostaining of staged seminiferous tubules showed CECR2 in type A, intermediate and B spermatogonia, and less in preleptotene and leptotene spermatocytes. Histological defects were first apparent in Cecr2GT/Del testes at P24, and RNA-seq analysis revealed 387 differentially expressed genes. This included 66 genes on the X chromosome (almost double the number on any other chromosome), all more highly expressed in Cecr2GT/Del testes. This inappropriate expression of X chromosome genes could be caused by a failure of effective meiotic sex chromosome inactivation. We identify several abnormally expressed genes that may contribute to defects in spermatogenesis at P24. Our results support a role for Cecr2 in juvenile spermatogenesis.

Herpes simplex virus hepatitis in a renal transplant recipient seronegative pre-transplant.

BACKGROUND: Herpes simplex virus (HSV) is a rare cause of acute viral hepatitis but has high mortality rates and primarily affects immunocompromised hosts. We report a case of HSV hepatitis in a 20-year-old female kidney transplant recipient who had 1000-fold elevations in transaminases on post-transplant day 14, and the strategies employed for diagnoses and treatment. METHODS: Routine laboratory, serological, and molecular viral testing was completed, and she underwent a bone marrow biopsy given initial suspicion of hemophagocytic lymphohistiocytosis (HLH). HSV serologic results and high transaminases triggered a liver biopsy. RESULTS: The patient presented with elevated transaminases (ALT 1731 U/L and AST 1400) and ferritin (1431 µg/L). Transaminases and ferritin peaked with an ALT of 6609 U/L, AST of 6525 U/L, and ferritin >50000 µg/L. Bone marrow biopsy revealed no definitive HLH. HSV-DNA PCR of blood was positive, and she was empirically started on intravenous acyclovir 10 mg/kg 3 times per day. Liver biopsy confirmed the histological diagnosis of HSV hepatitis. CONCLUSIONS: Given the high mortality rates associated with HSV hepatitis, it is crucial to determine pre-transplant HSV status, initiate appropriate antiviral prophylaxis, and to have a low threshold for investigating for HSV hepatitis and initiating treatment in patients with a suspected diagnosis.

Functional assays to assess the therapeutic potential of extracellular vesicles.

An important aspect in the development of extracellular vesicle (EV) therapeutics is identifying and quantifying the key features defining their identity, purity, sterility, potency and stability to ensure batch-to-batch reproducibility of their therapeutic efficacy. Apart from EV-inherent features, therapeutic efficacy depends on a variety of additional parameters, like dosing, frequency of application, and administration route, some of which can be addressed only in clinical trials. Before initiating clinical trials, EV-inherent features should be tested in well-standardized quantitative assays in vitro or in appropriate animal models in vivo. Ideally, such assays would predict if a particular EV preparation has the potential to achieve its intended therapeutic effects, and could be further developed into formal potency assays as published by the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use guidelines. Furthermore, such assays should facilitate the comparison of EV preparations produced in different batches, on different manufacturing platforms or deriving from different cell sources. For now, a wide spectrum of in vitro and in vivo assays has been used to interrogate the therapeutic functions of EVs. However, many cannot accurately predict therapeutic potential. Indeed, several unique challenges make it difficult to set up reliable assays to assess the therapeutic potential of EVs, and to develop such assays into formal potency tests. Here, we discuss challenges and opportunities around in vitro and in vivo testing of EV therapeutic potential, including the need for harmonization, establishment of formal potency assays and novel developments for functional testing.