A High-throughput Automated ELISA Assay for Detection of IgG Antibodies to the SARS-CoV-2 Spike Protein.

The SARS-CoV-2 pandemic and vaccination campaign has illustrated the need for high throughput serological assays to quantitatively measure antibody levels. Here, we present a protocol for a high-throughput colorimetric ELISA assay to detect IgG antibodies against the SARS-CoV-2 spike protein. The assay robustly distinguishes positive from negative samples, while controlling for potential non-specific binding from serum samples. To further eliminate background contributions, we demonstrate a computational pipeline for fitting ELISA titration curves, that produces an extremely sensitive antibody signal metric for quantitative comparisons across samples and time.

Doppler US of the liver made simple.

Doppler ultrasonography (US) is usually the first-line modality for evaluating flow in native liver vessels and transjugular intrahepatic portosystemic shunts (TIPS). Waveforms, which represent flow in each of the major vessels and in TIPS, have been well described. The appearance of these waveforms should be recognized, and the mechanisms behind their generation should be understood by those interpreting these examinations. Understanding how waveforms are formed--that is, their mechanisms for generation--is predicated on knowing basic vascular Doppler concepts and established nomenclature. This article is a review of these basic concepts and nomenclature as applied to the interpretation of liver Doppler US waveforms.

Female sex, early-onset hypertension, and risk of dementia.

OBJECTIVE: To evaluate the association of early-adulthood and mid-adulthood hypertension with dementia in men and women. METHODS: We evaluated 5,646 members of a diverse integrated health care delivery system who had clinical examinations and health survey data from 1964 to 1973 (mean age 32.7 years; early adulthood) and 1978-1985 (mean age 44.3 years; mid-adulthood) and were members as of January 1, 1996 (mean age 59.8 years). Hypertension categories based on measurements of blood pressure (BP) and change in hypertension categories between the 2 examinations (e.g., onset hypertension) were used to predict dementia incidence from January 1, 1996, to September 30, 2015. Cox proportional hazard models were adjusted for demographics, vascular comorbidities, and hypertension treatment; inverse probability weighting accounted for differential attrition between first BP measurement and start of follow-up. RESULTS: A total of 532 individuals (9.4%) were diagnosed with dementia. Early adulthood hypertension was not associated with dementia, though effect estimates were elevated among women. Mid-adulthood hypertension was associated with 65% (95% confidence interval [CI] 1.25-2.18) increased dementia risk among women but not men. Onset of hypertension in mid-adulthood predicted 73% higher dementia risk in women (95% CI 1.24-2.40) compared to stable normotensive. There was no evidence that hypertension or changes in hypertension increased dementia risk among men. CONCLUSIONS: Though midlife hypertension was more common in men, it was only associated with dementia risk in women. Sex differences in the timing of dementia risk factors have important implications for brain health and hypertension management.

Soluble extracellular Klotho decreases sensitivity to cigarette smoke induced cell death in human lung epithelial cells.

Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death in the US and is associated with an abnormal inflammatory response to cigarette smoke (CS). Exposure to CS induces oxidative stress and can result in cellular senescence in the lung. Cellular senescence can then lead to decreased proliferation of epithelial cells, the destruction of alveolar structure and pulmonary emphysema. The anti-aging gene, klotho, encodes a membrane bound protein that has been shown to be a key regulator of oxidative stress and cellular senescence. In this study the role of Klotho (KL) with regard to oxidative stress and cellular senescence was investigated in human pulmonary epithelial cells exposed to cigarette smoke. Individual clones that stably overexpress Klotho were generated through retroviral transfection and geneticin selection. Klotho overexpression was confirmed through RT-qPCR, Western blotting and ELISA. Compared to control cells, constitutive Klotho overexpression resulted in decreased sensitivity to cigarette smoke induced cell death in vitro via a reduction of reactive oxygen species and a decrease in the expression of p21. Our results suggest that increasing Klotho level in pulmonary epithelial cells may be a promising strategy to reduce cellular senescence and mitigate the risk for the development of COPD.