Marginal warming associated with a COVID-19 quarantine and the implications for disease transmission.

During January-February 2020, parts of China faced restricted mobility under COVID-19 quarantines, which have been associated with improved air quality. Because particulate pollutants scatter, diffuse, and absorb incoming solar radiation, a net negative radiative forcing, decreased air pollution can yield surface warming. As such, this study (1) documents the evolution of China's January-February 2020 air temperature and concurrent particulate changes; (2) determines the temperature response related to reduced particulates during the COVID-19 quarantine (C19Q); and (3) discusses the conceptual implications for temperature-dependent disease transmission. C19Q particulate evolution is monitored using satellite analyses, and concurrent temperature anomalies are diagnosed using surface stations and Aqua AIRS imagery. Meanwhile, two WRF-Chem simulations are forced by normal emissions and the satellite-based urban aerosol changes, respectively. Urban aerosols decreased from 27.1% of pre-C19Q aerosols to only 17.5% during C19Q. WRF-Chem resolved ~0.2 °C warming across east-central China, that represented a minor, though statistically significant contribution to C19Q temperature anomalies. The largest area of warming is concentrated south of Chengdu and Wuhan where temperatures increased between +0.2-0.3 °C. The results of this study are important for understanding the anthropogenic forcing on regional meteorology. Epidemiologically, the marginal, yet persistent, warming during C19Q may retard temperature-dependent disease transmission, possibly including SARS-CoV-2.

Colonic mucosal potential differences in the management of 21-hydroxylase deficiency.

Use of the colonic potential difference as a means of assessing the efficacy of different suppressive steroid regimens was explored in a patient with incomplete 21-hydroxylase deficiency. Changes in the potential difference were found to closely reflect changes in the plasma concentration of hormones such as aldosterone, androstenedione, dehydroepiandrosterone, and dehydroepiandrosterone sulfate. Dexamethasone, which produced the most marked change in the potential difference, also produced the most suppression of the plasma steroid concentrations. It is suggested that the colonic potential difference can be used as a simple alternate means of assessing the efficacy of suppressive steroid therapy in some patients with 21-hydroxylase deficiency.

Use of the artificial beta cell (ABC) in the assessment of peripheral insulin sensitivity: effect of chromium supplementation in diabetic patients.

The artificial beta cell (ABC), a closed-loop insulin delivery system, was used to determine insulin sensitivity. Progressively increasing glucose loads were administered after initial stabilization of the blood glucose at euglycemic levels such that the serum C-peptide was suppressed. The amount of insulin required to maintain euglycemia was considered a measure of sensitivity to insulin. Six stable maturity onset diabetics were studied before and after supplementation with chromium-rich brewer's yeast. All patients demonstrated an increase in sensitivity to insulin as indicated by a decrease in the fasting blood glucose concentration and a decrease in insulin requirement during the glucose challenge (P less than 0.02). The data obtained support the hypothesis that chromium or some other factor(s) present in brewer's yeast potentiates the peripheral effects of insulin. It remains to be established whether this effect occurs at the receptor or post-receptor level.

Pseudo-Cushing's syndrome: the role of alcohol.

The mechanisms responsible for the genesis of pseudo-Cushing's syndrome are poorly understood. We studied the effect of acute ethanol administration on the hypothalamic-pituitary-adrenal axis in five chronic alcoholic patients and three normal volunteers. Ethanol was administered alone and together with beta 1-24 ACTH given intravenously. Baseline plasma ACTH and cortisol concentrations were significantly higher in the patients than in normal controls (p less than 0.05). Acute ethanol administration produced no significant change in the mean plasma ACTH concentration, failed to augment the effect of exogenous ACTH on the adrenal gland, and produced similar changes in the serum cortisol and aldosterone concentration in both the normal controls and the alcoholic patients. We speculate that pseudo-Cushing's syndrome may represent a state of stress-induced hypercortisolemia secondary to multiple episodes of subacute withdrawal from ethanol.