Background Individuals can test positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by molecular assays following the resolution of their clinical disease. Recent studies indicate that SARS-CoV-2 antigen–based tests are likely to be positive early in the disease course, when there is an increased likelihood of high levels of infectious virus. Methods Upper respiratory specimens from 251 participants with coronavirus disease 2019 symptoms (≤7 days from symptom onset) were prospectively collected and tested with a lateral flow antigen test and a real-time polymerase chain reaction (rt-PCR) assay for detection of SARS-CoV-2. Specimens from a subset of the study specimens were utilized to determine the presence of infectious virus in the VeroE6TMPRSS2 cell culture model. Results The antigen test demonstrated a higher positive predictive value (90%) than rt-PCR (70%) when compared to culture-positive results. The positive percentage agreement for detection of infectious virus for the antigen test was similar to rt-PCR when compared to culture results. Conclusions The correlation between SARS-CoV-2 antigen and SARS-CoV-2 culture positivity represents a significant advancement in determining the risk for potential transmissibility beyond that which can be achieved by detection of SARS-CoV-2 genomic RNA. SARS-CoV-2 antigen testing can facilitate low-cost, scalable, and rapid time-to-result, while providing good risk determination of those who are likely harboring infectious virus, compared to rt-PCR.

Ischemic and excitotoxic insults to the brain induce rapid production of tumor necrosis factor-alpha (TNF), but the role of TNF in neuronal responses to brain injury are unclear. Two different TNF receptors (p55 and p75) are expressed in neurons and glia. To understand the role of TNF in brain injury, we generated mice that lack p55, p75, or both receptors. We report that neuronal damage after focal cerebral ischemia-reperfusion is significantly increased in mice lacking p55 receptors (85+/-7 mm3 infarct volume; mean +/- SD) compared with wild-type mice (70+/-8 mm3) and mice lacking p75 receptors (72+/-6 mm3). Moreover, mice lacking p55 receptors exhibited increased degeneration of CA3 hippocampal neurons after administration of the excitotoxin kainic acid compared with wild-type mice and mice lacking p75 receptors. When taken together with recent data showing that TNF can prevent apoptosis of cultured neurons exposed to oxidative and metabolic insults, our findings suggest that TNF plays a neuroprotective role after acute brain insults.

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Individuals can test positive for SARS-CoV-2 by real-time polymerase chain reaction (RT-PCR) after no longer being infectious.1-8 Positive SARS-CoV-2 antigen-based testing exhibits a temporal pattern that corresponds with active, replicating virus and could therefore be a more accurate predictor of an individuals potential to transmit SARS-CoV-2.2,3,9 Using the BD Veritor System for Rapid Detection of SARS-CoV-2 later flow antigen detection test, we demonstrate a higher concordance of antigen-positive test results with the presence of cultured, infectious virus when compared to RT-PCR. When compared to infectious virus isolation, the sensitivity of antigen-based testing is similar to RT-PCR. The correlation between SARS-CoV-2 antigen and SARS-CoV-2 culture represents a significant advancement in determining the risk for potential transmissibility beyond that which can be achieved by detection of SARS-CoV-2 genomic RNA. Coupled with a rapid time-to-result, low cost, and scalability, antigen-based testing should facilitate effective implementation of testing and public health interventions that will better contain COVID-19.

Objective Thirteen human papillomavirus (HPV) genotypes are associated with the highest risk of cervical disease/cancer; however, the risk of disease progression and cancer is genotype dependent. The objective of this systematic review was to examine evidence for high-grade cervical intraepithelial neoplasia (≥CIN 3) risk discrimination using HPV genotyping. Materials and Methods A systematic review of English and non-English articles through MEDLINE, Cochrane, clinicaltrials.gov, and abstracts presented at relevant professional society conferences were searched from 2000 to 2019. Search terms included: cervical cancer screening, HPV genotyping, CIN, HPV persistence, humans, and colposcopy; prospective, controlled trials, observational studies, and retrospective studies of residual specimens; evidence included HPV genotyping (beyond genotypes 16/18/45) results. Data were obtained independently by authors using predefined fields. Risk of bias was evaluated with a modified Newcastle-Ottawa Scale. The Grading of Recommendations, Assessment, Development and Evaluation methodology facilitated overall quality of evidence evaluation for risk estimation. The study protocol was registered with the PROSPERO International Prospective Register of Systematic Reviews (CRD42018091093). The primary outcome was CIN 3 or worse risk both at baseline and at different follow-up periods. Results Of 236 identified sources, 60 full texts were retrieved and 16 articles/sources were included. Risk of bias was deemed low; the overall quality of evidence for CIN 3 or worse risk with negative for intraepithelial lesions or malignancies or low-grade squamous intraepithelial cytology was assessed as moderate; that with atypical squamous cells-undetermined significance and “all cytology” was assessed as high. Clinical and methodological heterogeneity precluded meta-analysis. Human papillomavirus genotyping discriminated risk of CIN 3 or worse to a clinically significant degree, regardless of cytology result. Conclusions The evidence supports a clinical utility for HPV genotyping in risk discrimination during cervical cancer screening.

Integrins are integral membrane proteins that mediate adhesive interactions of cells with the extracellular matrix and with other cells. Integrin engagement results in activation of intracellular signaling cascades that effect several different cellular responses including motility, proliferation and survival. Although integrins are known to provide cell survival signaling in various types of non-neuronal cells, the possibility that integrins modulate neuron survival has not been explored. We now report data demonstrating a neuroprotective function of integrins in embryonic hippocampal neurons. Neurons grown on laminin, an integrin ligand, exhibit increased resistance to glutamate-induced apoptosis compared with neurons grown on polylysine. Neurons expressed integrin b1 and treatment of cultures with an antibody against integrin b1 abolished the protective effect of laminin. Neurons maintained on laminin exhibited a sustained activation of the Akt signaling pathway demonstrated in immunoblot analyses using an antibody that selectively recognizes phosphorylated Akt. The neuroprotective effect of integrin engagement by laminin was mimicked by an IKLLI-containing integrin-binding peptide and was abolished by treatment of neurons with the PI3 kinase inhibitor wortmanin. Levels of the anti-apoptotic protein Bcl-2 were increased in neurons grown on laminin and decreased by wortmanin, suggesting a mechanism for the neuroprotective effect of integrin-mediated signaling. The ability of integrin-mediated signaling to prevent glutamateinduced apoptosis suggests a mechanism whereby neuron± substrate interactions can promote neuron survival under conditions of glutamate receptor overactivation.

Tests that detect the presence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigen in clinical specimens from the upper respiratory tract can provide a rapid means of coronavirus disease 2019 (COVID-19) diagnosis and help identify individuals who may be infectious and should isolate to prevent SARS-CoV-2 transmission. This systematic review assesses the diagnostic accuracy of SARS-CoV-2 antigen detection in COVID-19 symptomatic and asymptomatic individuals compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) and summarizes antigen test sensitivity using meta-regression. In total, 83 studies were included that compared SARS-CoV-2 rapid antigen-based lateral flow testing (RALFT) to RT-qPCR for SARS-CoV-2. Generally, the quality of the evaluated studies was inconsistent; nevertheless, the overall sensitivity for RALFT was determined to be 75.0% (95% confidence interval: 71.0–78.0). Additionally, RALFT sensitivity was found to be higher for symptomatic vs. asymptomatic individuals and was higher for a symptomatic population within 7 days from symptom onset compared to a population with extended days of symptoms. Viral load was found to be the most important factor for determining SARS-CoV-2 antigen test sensitivity. Other design factors, such as specimen storage and anatomical collection type, also affect the performance of RALFT. RALFT and RT-qPCR testing both achieve high sensitivity when compared to SARS-CoV-2 viral culture.

Axon demyelination contributes to the loss of sensory and motor function following injury or disease in the central nervous system. Numerous reports have demonstrated that myelination can be achieved in neuron/oligodendrocyte co-cultures. However, the ability to selectively treat neuron or oligodendrocyte (OL) cell bodies in co-cultures improves the value of these systems when designing mechanism-based therapeutics. We have developed a microfluidic-based compartmentalized culture system to achieve segregation of neuron and OL cell bodies while simultaneously allowing the formation of myelin sheaths. Our microfluidic platform allows for a high replicate number, minimal leakage, and high flexibility. Using a custom built lid, fit with platinum electrodes for electrical stimulation (10-Hz pulses at a constant 3 V with ~190 kΩ impedance), we employed the microfluidic platform to achieve activity-dependent myelin segment formation. Electrical stimulation of dorsal root ganglia resulted in a fivefold increase in the number of myelinated segments/mm² when compared to unstimulated controls (19.6 ± 3.0 vs. 3.6 ± 2.3 MBP+ segments/mm²). This work describes the modification of a microfluidic, multi-chamber system so that electrical stimulation can be used to achieve increased levels of myelination while maintaining control of the cell culture microenvironment.