Functional Assessment of Cardiac Responses of Adult Zebrafish (Danio rerio) to Acute and Chronic Temperature Change Using High-Resolution Echocardiography

The zebrafish (Danio rerio) is an important organism as a model for understanding vertebrate cardiovascular development. However, little is known about adult ZF cardiac function and how contractile function changes to cope with fluctuations in ambient temperature. The goals of this study were to: 1) determine if high resolution echocardiography (HRE) in the presence of reduced cardiodepressant anesthetics could be used to accurately investigate the structural and functional properties of the ZF heart and 2) if the effect of ambient temperature changes both acutely and chronically could be determined non-invasively using HRE in vivo. Heart rate (HR) appears to be the critical factor in modifying cardiac output (CO) with ambient temperature fluctuation as it increases from 78 ± 5.9 bpm at 18°C to 162 ± 9.7 bpm at 28°C regardless of acclimation state (cold acclimated CA– 18°C; warm acclimated WA– 28°C). Stroke volume (SV) is highest when the ambient temperature matches the acclimation temperature, though this difference did not constitute a significant effect (CA 1.17 ± 0.15 μL at 18°C vs 1.06 ± 0.14 μl at 28°C; WA 1.10 ± 0.13 μL at 18°C vs 1.12 ± 0.12 μl at 28°C). The isovolumetric contraction time (IVCT) was significantly shorter in CA fish at 18°C. The CA group showed improved systolic function at 18°C in comparison to the WA group with significant increases in both ejection fraction and fractional shortening and decreases in IVCT. The decreased early peak (E) velocity and early peak velocity / atrial peak velocity (E/A) ratio in the CA group are likely associated with increased reliance on atrial contraction for ventricular filling

Neuroimaging Feature Extraction using a Neural Network Classifier for Imaging Genetics

A major issue in the association of genes to neuroimaging phenotypes is the high dimension of both genetic data and neuroimaging data. In this article, we tackle the latter problem with an eye toward developing solutions that are relevant for disease prediction. Supported by a vast literature on the predictive power of neural networks, our proposed solution uses neural networks to extract from neuroimaging data features that are relevant for predicting Alzheimer's Disease (AD) for subsequent relation to genetics. Our neuroimaging-genetic pipeline is comprised of image processing, neuroimaging feature extraction and genetic association steps. We propose a neural network classifier for extracting neuroimaging features that are related with disease and a multivariate Bayesian group sparse regression model for genetic association. We compare the predictive power of these features to expert selected features and take a closer look at the SNPs identified with the new neuroimaging features.Comment: Under revie

Substantial and sustained reduction in under-5 mortality, diarrhea, and pneumonia in Oshikhandass, Pakistan : Evidence from two longitudinal cohort studies 15 years apart

Funding Information: Study 1 was funded through the Applied Diarrheal Disease Research Program at Harvard Institute for International Development with a grant from USAID (Project 936–5952, Cooperative Agreement # DPE-5952-A-00-5073-00), and the Aga Khan Health Service, Northern Areas and Chitral, Pakistan. Study 2 was funded by the Pakistan US S&T Cooperative Agreement between the Pakistan Higher Education Commission (HEC) (No.4–421/PAK-US/HEC/2010/955, grant to the Karakoram International University) and US National Academies of Science (Grant Number PGA-P211012 from NAS to the Fogarty International Center). The funding bodies had no role in the design of the study, data collection, analysis, interpretation, or writing of the manuscript. Publisher Copyright: © 2020 The Author(s).Peer reviewedPublisher PD

Gene Expression Profiling of Preovulatory Follicle in the Buffalo Cow: Effects of Increased IGF-I Concentration on Periovulatory Events

The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs) and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF) and apoptosis (BCL-2, FKHR, PAWR). These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development

Effect of hyperglycemia and the aldose reductase inhibitor tolrestat on sural nerve biochemistry and morphometry in advanced diabetic peripheral polyneuropathy

Tolrestat is a well tolerated nonhydantoin aldose reductase inhibitor that has been reported to improve nerve conduction in diabetic animals and humans. Its effects on nerve biochemistry and structure have not been studied in patients with diabetic neuropathy. Patients with advanced diabetic neuropathy treated with long-term open-label tolrestat were randomly assigned to continuation on drug treatment or to placebo-controlled drug withdrawal for 12 months. At the end of this period, sural nerve biopsies were obtained for measurement of glucose, sorbitol, and fructose content, and for detailed morphometric analysis. Tolrestat ameliorated the glucose-mediated increase in sorbitol and fructose in sural nerve tissue. No statistically significant differences in nerve morphometry emerged between the two groups; however, both treatment groups exhibited increased nerve-fiber regeneration and normalization of axo-glial dysjunction and segmental demyelination following long-term tolrestat treatment. These findings are similar to those previously reported in a placebo-controlled sequential nerve biopsy study with the aldose reductase inhibitor sorbinil. Thus tolrestat is a biochemically effective aldose reductase inhibitor in human diabetic nerve with potential therapeutic efficacy for diabetic neuropathy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30702/1/0000347.pd

Longitudinal position of zebrafish.

<p>The ultrasound transducer beam (70 MHz) was positioned at about 85 degrees to ventral surface of the anesthetized zebrafish through all protocols. ZF were placed in a 45 ml custom-made water-jacketed glass chamber with the thermal probe (shown with the blue wire) inserted into the bath in proximity to the ZF.</p

Pulse wave Doppler image of ventricular inflow and outflow velocity.

<p>Ventricular inflow image was used to measure IVRT, IVCT, ET, early (e) filling peak velocity and atrial (a) filling peak velocity in a WA ZF at: (A) 28<b>°</b>C and (B) 18<b>°</b>C. Note the difference in x-axis in the 28<b>°</b>C condition and 18<b>°</b>C condition. (C) Ventricular outflow peak velocity (VOPV) of a WA ZF at 28<b>°</b>C. The Y-axis indicates velocity (mm/s) and the x-axis indicates time (ms). ET, ejection time; IVCT, isovolumetric contraction time; IVRT, Isovolumetric relaxation time; Vel, velocity.</p