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1.
Lancet Reg Health Am ; 19: 100449, 2023 Mar.
Article in English | MEDLINE | ID: covidwho-2240692

ABSTRACT

Background: Schools are high-risk settings for SARS-CoV-2 transmission, but necessary for children's educational and social-emotional wellbeing. Previous research suggests that wastewater monitoring can detect SARS-CoV-2 infections in controlled residential settings with high levels of accuracy. However, its effective accuracy, cost, and feasibility in non-residential community settings is unknown. Methods: The objective of this study was to determine the effectiveness and accuracy of community-based passive wastewater and surface (environmental) surveillance to detect SARS-CoV-2 infection in neighborhood schools compared to weekly diagnostic (PCR) testing. We implemented an environmental surveillance system in nine elementary schools with 1700 regularly present staff and students in southern California. The system was validated from November 2020 to March 2021. Findings: In 447 data collection days across the nine sites 89 individuals tested positive for COVID-19, and SARS-CoV-2 was detected in 374 surface samples and 133 wastewater samples. Ninety-three percent of identified cases were associated with an environmental sample (95% CI: 88%-98%); 67% were associated with a positive wastewater sample (95% CI: 57%-77%), and 40% were associated with a positive surface sample (95% CI: 29%-52%). The techniques we utilized allowed for near-complete genomic sequencing of wastewater and surface samples. Interpretation: Passive environmental surveillance can detect the presence of COVID-19 cases in non-residential community school settings with a high degree of accuracy. Funding: County of San Diego, Health and Human Services Agency, National Institutes of Health, National Science Foundation, Centers for Disease Control.

2.
The FASEB Journal ; 35(S1), 2021.
Article in English | Wiley | ID: covidwho-1234017

ABSTRACT

The paraventricular nucleus of the hypothalamus (PVN) is critical in autonomic and endocrine control. Previous work has indicated that PVN dysregulation is associated with a variety of cardiometabolic diseases including those related to obesity. However, investigations have focused primarily on molecular alterations. Importantly, changes in the anatomical structure of brain networks also leads to functional alterations. While electron microscopy (EM) can provide nanometer resolution of normal/abnormal brain structures, an inherent limitation of traditional transmission EM is the random sampling of an object within a large region of interest (i.e. PVN). To overcome the inherent limitations of EM, we introduce an approach that utilizes large field of view high-resolution focused ion beam scanning electron microscopy (SEM) of the PVN. Six week old male C57Bl/6J mice were fed a high fat diet (HFD) or normal chow for 10 weeks (n=4/group), and brains prepared for SEM imaging. Due to the COVID-19 pandemic, which required social distancing, SEM imaging and analysis was conducted remotely (i.e. at home) using a virtual network computing approach. We first acquired interactive, zoomable maps of the PVN at a low magnification. This image was then used to navigate precisely to the PVN and acquire a high-resolution image encompassing ~30-40% of the nucleus (Figure). With this approach, we could rapidly scan for any visually apparent anatomical alterations. This initial evaluation revealed more electron dense regions within PVN neuronal nuclei, potentially indicative of heterochromatin clusters, in HFD mice relative to normal chow counterparts. Thus, we performed subsequent analysis on 80-120 neurons from each diet group by outlining neuronal nuclear envelopes and quantifying pixel distribution. This provided an indirect estimate of heterochromatin (i.e. dark pixels) and euchromatin (lighter pixels), with a shift towards darker pixels suggestive of increased chromatin ?clustering?. The area and perimeter of analyzed PVN neuronal nuclei between groups was similar (e.g. area: 4.0±2.9 vs 3.7±1.4 µm2x106, normal chow vs HFD, p<0.05). However, histogram analysis of pixel intensities revealed positive kurtosis, indicating that HFD resulted in a redistribution of nuclear pixels to dark and light pixel intensities (-0.05±0.03 vs 0.12±0.03 a.u., normal chow vs HFD, p<0.05). Measures of skew, an indicator of curve symmetry, further revealed a leftward pixel shift (i.e. more negative skew toward dark pixels) in diet-induced obese mice (-0.48±0.01 vs -0.64±0.01 a.u., normal chow vs HFD, p<0.05). Finally, we created a PVN ?map? to examine where the most altered neurons were located. In short, following HFD feeding, ?altered? neurons were distributed throughout the entire PVN and not located in discrete PVN sub-nuclei. Collectively, these findings present an approach that allows for the precise placement of PVN cells within the overall region (i.e. locating a house within a city). Moreover, they suggest that HFD feeding may disrupt PVN neuronal chromatin structure, which may be reflective of epigenetic modifications and/or transcriptional alterations.

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