Abnormal Excitability of Oblique Dendrites Implicated in Early Alzheimer's: A Computational Study

The integrative properties of cortical pyramidal dendrites are essential to the neural basis of cognitive function, but the impact of amyloid beta protein (aβ) on these properties in early Alzheimer's is poorly understood. In animal models, electrophysiological studies of proximal dendrites have shown that aβ induces hyperexcitability by blocking A-type K+ currents (IA), disrupting signal integration. The present study uses a computational approach to analyze the hyperexcitability induced in distal dendrites beyond the experimental recording sites. The results show that back-propagating action potentials in the dendrites induce hyperexcitability and excessive calcium concentrations not only in the main apical trunk of pyramidal cell dendrites, but also in their oblique dendrites. Evidence is provided that these thin branches are particularly sensitive to local reductions in IA. The results suggest the hypothesis that the oblique branches may be most vulnerable to disruptions of IA by early exposure to aβ, and point the way to further experimental analysis of these actions as factors in the neural basis of the early decline of cognitive function in Alzheimer's

Assessment of prevalence and risk factors of delirium in kidney disease patients undergoing renal dialysis: A prospective observational study

Context: Studies have shown that delirium is common in intensive care unit settings, postsurgery, and in elderly. There are various predisposing risk factors for same. There is evidence of delirium occurring after dialysis. Aims: The aim of this study was to assess the prevalence and risk factor of delirium in kidney disease (both acute and chronic) patients undergoing dialysis. Settings and Design: A 1-year prospective observational study in a tertiary care hospital. Subjects and Methods: The study included admitted patients of kidney disease (acute and chronic) requiring dialysis, aged 18 years or more. All patients who were already in delirium before dialysis were excluded. Mental status examination was done, and Confusion Assessment Method (CAM) scale was applied on the included patients to make a diagnosis of delirium. Statistical Analysis Used: For risk factors, sociodemographic data, past history of delirium, number of dialysis received, and blood investigations were collected. P value for all parameters was calculated using Chi-square, Fisher's exact, and unpaired t-test. Results: The prevalence of delirium was 20% after dialysis. Risk factors identified were past history of delirium, >3 dialysis received, the presence of hypertension, increased urea, creatinine, hemoglobin, white blood cells levels, and increased LFT's (significant P value). Conclusions: The prevalence of delirium in dialysis group patients is high. There are multiple risk factors for same and can be predicted and taken care of to reduce the long-term consequences of delirium

Effectiveness of COVID-19 Treatment With Nirmatrelvir-Ritonavir or Molnupiravir Among U.S. Veterans: Target Trial Emulation Studies With One-Month and Six-Month Outcomes.

BackgroundInformation about the effectiveness of oral antivirals in preventing short- and long-term COVID-19-related outcomes in the setting of Omicron variant transmission and COVID-19 vaccination is limited.ObjectiveTo measure the effectiveness of nirmatrelvir-ritonavir and molnupiravir for outpatient treatment of COVID-19.DesignThree retrospective target trial emulation studies comparing matched cohorts of nirmatrelvir-ritonavir versus no treatment, molnupiravir versus no treatment, and nirmatrelvir-ritonavir versus molnupiravir.SettingVeterans Health Administration (VHA).ParticipantsNonhospitalized veterans in VHA care who were at risk for severe COVID-19 and tested positive for SARS-CoV-2 during January through July 2022.InterventionNirmatrelvir-ritonavir or molnupiravir pharmacotherapy.MeasurementsIncidence of any hospitalization or all-cause mortality at 30 days and from 31 to 180 days.ResultsEighty-seven percent of participants were male; the median age was 66 years, and 18% were unvaccinated. Compared with matched untreated control participants, those treated with nirmatrelvir-ritonavir (n = 9607) had lower 30-day risk for hospitalization (22.07 vs. 30.32 per 1000 participants; risk difference [RD], -8.25 [95% CI, -12.27 to -4.23] per 1000 participants) and death (1.25 vs. 5.47 per 1000 participants; RD, -4.22 [CI, -5.45 to -3.00] per 1000 participants). Among persons alive at day 31, reductions were seen in 31- to 180-day incidence of death (hazard ratio, 0.66 [CI, 0.49 to 0.89]) but not hospitalization (subhazard ratio, 0.90 [CI, 0.79 to 1.02]). Molnupiravir-treated participants (n = 3504) had lower 30-day and 31- to 180-day risks for death (3.14 vs. 13.56 per 1000 participants at 30 days; RD, -10.42 [CI, -13.49 to -7.35] per 1000 participants; hazard ratio at 31 to 180 days, 0.67 [CI, 0.48 to 0.95]) but not hospitalization. A difference in 30-day or 31- to 180-day risk for hospitalization or death was not observed between matched nirmatrelvir- or molnupiravir-treated participants.LimitationThe date of COVID-19 symptom onset for most veterans was unknown.ConclusionNirmatrelvir-ritonavir was effective in reducing 30-day hospitalization and death. Molnupiravir was associated with a benefit for 30-day mortality but not hospitalization. Further reductions in mortality from 31 to 180 days were observed with both antivirals.Primary funding sourceU.S. Department of Veterans Affairs

A System for Phenotype Harmonization in the NHLBI Trans-Omics for Precision Medicine (TOPMed) Program

Genotype-phenotype association studies often combine phenotype data from multiple studies to increase statistical power. Harmonization of the data usually requires substantial effort due to heterogeneity in phenotype definitions, study design, data collection procedures, and data-set organization. Here we describe a centralized system for phenotype harmonization that includes input from phenotype domain and study experts, quality control, documentation, reproducible results, and data-sharing mechanisms. This system was developed for the National Heart, Lung, and Blood Institute's Trans-Omics for Precision Medicine (TOPMed) program, which is generating genomic and other -omics data for more than 80 studies with extensive phenotype data. To date, 63 phenotypes have been harmonized across thousands of participants (recruited in 1948-2012) from up to 17 studies per phenotype. Here we discuss challenges in this undertaking and how they were addressed. The harmonized phenotype data and associated documentation have been submitted to National Institutes of Health data repositories for controlled access by the scientific community. We also provide materials to facilitate future harmonization efforts by the community, which include 1) the software code used to generate the 63 harmonized phenotypes, enabling others to reproduce, modify, or extend these harmonizations to additional studies, and 2) the results of labeling thousands of phenotype variables with controlled vocabulary terms