C9orf72-ALS human iPSC microglia are pro-inflammatory and toxic to co-cultured motor neurons via MMP9.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron loss, with additional pathophysiological involvement of non-neuronal cells such as microglia. The commonest ALS-associated genetic variant is a hexanucleotide repeat expansion (HRE) mutation in C9orf72. Here, we study its consequences for microglial function using human iPSC-derived microglia. By RNA-sequencing, we identify enrichment of pathways associated with immune cell activation and cyto-/chemokines in C9orf72 HRE mutant microglia versus healthy controls, most prominently after LPS priming. Specifically, LPS-primed C9orf72 HRE mutant microglia show consistently increased expression and release of matrix metalloproteinase-9 (MMP9). LPS-primed C9orf72 HRE mutant microglia are toxic to co-cultured healthy motor neurons, which is ameliorated by concomitant application of an MMP9 inhibitor. Finally, we identify release of dipeptidyl peptidase-4 (DPP4) as a marker for MMP9-dependent microglial dysregulation in co-culture. These results demonstrate cellular dysfunction of C9orf72 HRE mutant microglia, and a non-cell-autonomous role in driving C9orf72-ALS pathophysiology in motor neurons through MMP9 signaling.

Developing a simulation-based learning model for acute medical education during COVID-19 pandemic with Simulation via Instant Messaging - Birmingham Advance (SIMBA).

Simulation-based learning (SBL) is well-established in medical education and has gained popularity, particularly during the COVID-19 pandemic when in-person teaching is infeasible. SBL replicates real-life scenarios and provides a fully immersive yet safe learning environment to develop clinical competency. Simulation via Instant Messaging - Birmingham Advance (SIMBA) is an exemplar of SBL, which we previously showed to be effective in endocrinology and diabetes. Previous studies reported the efficacy of SBL in acute medicine. We studied SIMBA as a learning intervention for healthcare professionals interested in acute medicine and defined our aims using the Kirkpatrick model: (i) develop an SBL tool to improve case management; (ii) evaluate experiences and confidence before and after; and (iii) compare efficacy across training levels.Three sessions were conducted, each representing a PDSA cycle (Plan-Do-Study-Act), consisting of four cases and advertised to healthcare professionals at our hospital and social media. Moderators facilitated progression through 25 min simulations and adopted patient and clinical roles as appropriate. Consultants chaired discussion sessions using relevant guidelines. Presimulation and postsimulation questionnaires evaluated self-reported confidence, feedback and intended changes to clinical practice.Improvements were observed in self-reported confidence managing simulated cases across all sessions. Of participants, 93.3% found SIMBA applicable to clinical practice, while 89.3% and 88.0% felt SIMBA aided personal and professional development, respectively. Interestingly, 68.0% preferred SIMBA to traditional teaching methods. Following participant feedback, more challenging cases were included, and we extended the time for simulation and discussion. The transcripts were amended to facilitate more participant-moderator interaction representing clinical practice. In addition, we refined participant recruitment over the three sessions. In cycle 1, we advertised incentives: participation counted towards teaching requirements, certificates and feedback. To rectify the reduction in participants in cycle 2, we implemented new advertisement methods in cycle 3, including on-site posters, reminder emails and recruitment of the defence deanery cohort.

Utility of Simulation via Instant Messaging - Birmingham Advance (SIMBA) in medical education during COVID-19 pandemic.

BACKGROUND: Simulation via Instant Messaging - Birmingham Advance (SIMBA) aimed to improve clinicians' confidence in managing various clinical scenarios during the COVID-19 pandemic. METHODS: Five SIMBA sessions were conducted between May and August 2020. Each session included simulation of scenarios and interactive discussion. Participants' self-reported confidence, acceptance, and relevance of the simulated cases were measured. RESULTS: Significant improvement was observed in participants' self-reported confidence (overall n = 204, p<0.001; adrenal n = 33, p<0.001; thyroid n = 37, p<0.001; pituitary n = 79, p<0.001; inflammatory bowel disease n = 17, p<0.001; acute medicine n = 38, p<0.001). Participants reported improvements in clinical competencies: patient care 52.0% (n = 106/204), professionalism 30.9% (n = 63/204), knowledge on patient management 84.8% (n = 173/204), systems-based practice 48.0% (n = 98/204), practice-based learning 69.6% (n = 142/204) and communication skills 25.5% (n = 52/204). CONCLUSION: SIMBA is a novel pedagogical virtual simulation-based learning model that improves clinicians' confidence in managing conditions across various specialties.

Recipient Sex Differences in Kidney Graft Survival Are Influenced by Donor Sex and Recipient Age.

OBJECTIVES: An age-dependent interaction has been described for the effect of donor-recipient sex mismatch on outcomes after kidney transplant in the United States. However, this has not been verified or tested in a different cohort from another country. MATERIALS AND METHODS: Data of 25 140 deceased donor kidney transplant recipients (2000-2016) were retro-spectively analyzed at a population-cohort level using the United Kingdom transplant registry. Within sub-groups of donor sex, associations between recipient sex and death-censored graft survival were assessed for the cohort as a whole and within recipient age subgroups. RESULTS: No differences in graft survival were detected between female versus male recipients of male donor kidneys (adjusted hazard ratio: 1.05; P = .227). However, a significant interaction between the age and sex of recipients was identified (P = .007). Female recipients aged 25 to 44 years had significantly shorter graft survival than male recipients (adjusted hazard ratio: 1.27; P = .003), but this effect was reversed in recipients who were 45 years or older (adjusted hazard ratio: 0.94; P = .258), where there was a nonsignificant tendency for longer graft survival in females. No such effect was observed in the subgroup of female donor transplants, with no significant difference between female versus male recipients overall (adjusted hazard ratio: 1.02; P = .638) and no significant interaction with age (P = .470). CONCLUSIONS: Graft survival is influenced by the combination of recipient age and sex in recipients of male donor kidneys only. This work demonstrates findings broadly similar to published reports but presents differences in observed effect sizes among certain subgroups. Our research suggests further work is warranted to explore personalized approaches to age- and sex-adapted immunosuppression.

Review-Recent Advances in Nanosensors Built with Pre-Pulled Glass Nanopipettes and Their Applications in Chemical and Biological Sensing.

Nanosensors built with pre-pulled glass nanopipettes, including bare or chemically modified nanopipettes and fully or partially filled solid nanoelectrodes, have found applications in chemical and biological sensing via resistive-pulse, current rectification, and electrochemical sensing. These nanosensors are easily fabricated and provide advantages through their needle-like geometry with nanometer-sized tips, making them highly sensitive and suitable for local measurements in extremely small samples. The variety in the geometry and layout have extended sensing capabilities. In this review, we will outline the fundamentals in fabrication, modification, and characterization of those pre-pulled glass nanopipette based nanosensors and highlight the most recent progress in their development and applications in real-time monitoring of biological processes, chemical ion sensing, and single entity analysis.

Donor-recipient Sex Differences Do Not Affect Survival Outcomes After Kidney Transplantation: A Population Cohort Study.

BACKGROUND: Donor factors can influence decision making for organ utilization for potential kidney transplant candidates. Prior studies exploring the effect of donor-recipient sex matching on kidney transplant outcomes have reported heterogenous and conflicting results. The aim of this contemporary population-cohort analysis was to explore the effect of donor-recipient sex matching on kidney transplant outcomes in the United Kingdom. METHODS: In this retrospective, observational study, we analyzed all patients receiving kidney-alone transplants between 2003 and 2018 using UK Transplant Registry data. Stratified by recipient sex, outcomes were compared between male and female donors with univariable/multivariable analyses. RESULTS: Data were analyzed for 25 140 recipients. Of these, 13 414 (53.4%) of kidneys were from male donors and 15 690 (62.4%) of recipients were male. The odds of initial graft dysfunction (delayed graft function/primary nonfunction) were significantly lower for female donor kidneys transplanted into both male (adjusted odds ratio = 0.89, 95% confidence interval [CI] = 0.80-0.98, P = 0.019) and female (adjusted odds ratio = 0.81, 95% CI = 0.71-0.93, P = 0.003) recipients. Male recipients of female donor kidneys had creatinine levels at 1 year that were 6.3% higher (95% CI = 4.8%-7.7%, P < 0.001) than male recipients of male donor kidneys, with a similar sex difference of 4.1% (95% CI = 2.1%-6.1%, P < 0.001) observed within female recipients. However, neither patient nor graft survival was found to differ significantly by donor sex on either univariable or multivariable analysis. CONCLUSIONS: Our data provide contemporary data on sex mismatch for recipient counseling and reassurance with regards to equivalent long-term clinical outcomes based upon donor sex.

Altered microvascular hemodynamics during the induction and perpetuation of chronic gut inflammation.

Adoptive transfer of naïve CD4+ T cells into lymphopenic mice induces chronic small and large bowel inflammation similar to Crohn's disease. Although much is now known regarding the immunopathology in this model of inflammatory bowel disease, virtually nothing is known about the microvascular hemodynamic changes during the induction and perpetuation of chronic gut inflammation. In this study, CD4+CD45RBhigh T cells obtained from healthy C57BL/6 donor mice were transferred into lymphopenic recombinase-activating gene-1-deficient (RAG knockout) mice, which induced small and large bowel inflammation. At various time points following reconstitution (3 days-9 wk), intravital microscopy was used to examine the microvessels in the submucosa of the ileum and proximal colon following infusion of fluorescently labeled platelets and injection of rhodamine 6G (to label leukocytes). Hemodynamic measurements and the extent of blood cell adhesion to the venular wall were compared with measurements in unreconstituted RAG knockout controls. In <1 wk following reconstitution, velocity and wall shear rate of the arterioles decreased by >50% compared with controls, with this decrease also observed at 4-5 and 7-9 wk postreconstitution. At 7-9 wk, arteriolar diameters were found to be approximately 15% larger than in controls, but, despite this dilation, flow rates in the individual vessels were decreased by approximately 30%. Venular platelet and leukocyte adherence were not significantly elevated above controls; however, an association was found between platelet adherence and venular shear rate. In summary, significant decreases in arteriolar velocity and shear rates are observed in this model of chronic gut inflammation.

Ozagrel reverses streptozotocin-induced constriction of arterioles in rat retina.

Retinal blood flow decreases early in the progression of diabetic retinopathy; however, the mediators and mechanisms responsible for this decrease have yet to be determined. In this study, diabetes was induced by streptozotocin in rats, and retinal blood flow was measured via intravital microscopy 1 or 3 weeks following the induction of hyperglycemia. Additionally, retinal arteriolar diameters and flow were measured prior to and following acute administration of the thromboxane synthase inhibitor ozagrel to investigate the potential role of thromboxane in the observed constriction. Minimal changes in the retinal diameters and flow were observed at 1 week of diabetes; however, at 3 weeks of diabetes, arteriolar constriction and decreases in blood flow were significant. Notably, the constriction occurred only in the arterioles that were in closer proximity to the venules draining the retina. Acute administration of ozagrel reversed the constriction of the closely venule-paired arterioles. In summary, the results suggest that thromboxane mediates localized, venule-dependent arteriolar constriction induced by streptozotocin-induced diabetes in rats.

Contrasting effects of pseudoephedrine and papaverine in dextran sodium sulfate-induced colitis.

BACKGROUND: Dextran sodium sulfate (DSS) induces submucosal arteriolar constriction that reduces blood flow to the intestine, and the relevance of this decrease in flow needs further investigation. In the present study we examined the effects of a vasoconstrictor (pseudoephedrine) and a vasodilator (papaverine) on the outcome of DSS-induced colitis. METHODS: Mice were given DSS in drinking water for 6 days, with enemas on days 0, 1, 3, and 5 containing pseudoephedrine, papaverine, or no drug. At the conclusion of the 6-day protocol a disease activity index comprising weight loss, stool consistency, and rectal bleeding was evaluated, along with intravital microscopy observations of submucosal venular leukocyte and platelet adherence in the proximal colon and terminal ileum. RESULTS: Pseudoephedrine and papaverine had several contrasting effects on the outcome of DSS ingestion: pseudoephedrine induced the highest levels of weight loss, loose stools, venular platelet adherence, and overall disease activity index, while papaverine induced the highest levels of venular leukocyte adherence, but the lowest levels of rectal bleeding, loose stools, and overall disease activity index. CONCLUSIONS: The results suggest that vasoconstriction worsens the pathological consequences of DSS in the mouse model of colitis.