Effects of climate variables on the transmission of COVID-19: a systematic review of 62 ecological studies.

The new severe acute respiratory syndrome coronavirus 2 was initially discovered at the end of 2019 in Wuhan City in China and has caused one of the most serious global public health crises. A collection and analysis of studies related to the association between COVID-19 (coronavirus disease 2019) transmission and meteorological factors, such as humidity, is vital and indispensable for disease prevention and control. A comprehensive literature search using various databases, including Web of Science, PubMed, and Chinese National Knowledge Infrastructure, was systematically performed to identify eligible studies from Dec 2019 to Feb 1, 2021. We also established six criteria to screen the literature to obtain high-quality literature with consistent research purposes. This systematic review included a total of 62 publications. The study period ranged from 1 to 8 months, with 6 papers considering incubation, and the lag effect of climate factors on COVID-19 activity being taken into account in 22 studies. After quality assessment, no study was found to have a high risk of bias, 30 studies were scored as having moderate risks of bias, and 32 studies were classified as having low risks of bias. The certainty of evidence was also graded as being low. When considering the existing scientific evidence, higher temperatures may slow the progression of the COVID-19 epidemic. However, during the course of the epidemic, these climate variables alone could not account for most of the variability. Therefore, countries should focus more on health policies while also taking into account the influence of weather.

Sodium Tanshinone IIA Silate Alleviates High Glucose Induced Barrier Impairment of Human Retinal Pigment Epithelium through the Reduction of NF-κB Activation via the AMPK/p300 Pathway.

Purpose: The disruption of retinal pigment epithelium (RPE) barrier may perform a crucial role in the pathogenesis of diabetic retinopathy (DR). AMPK exerts several salutary effects on photoreceptors and the RPE function and improves retina abnormalities. The current study aimed to determine whether sodium tanshinone IIA silate (STS) has an inhibitory effect on ARPE-19 cell monolayer permeability under high glucose conditions, and establish the underlying mechanism.Methods: We used a model of high glucose (25 mmol glucose, HG) condition mimicking diabetes in ARPE-19 cells, to assess the protective effects of STS. The barrier function of RPE cells were measured by Transepithelial Electrical Resistance (TEER) and fluorescein isothiocyanate (FITC)-dextran permeability. The interaction of NF-κB p65 and p300 were tested using immunoblotting and immunoprecipitation and immunofluorescence assay. Protein levels were assayed using Western blot.Results: We found STS promoted the phosphorylation of AMP-activated protein kinase (AMPK) at T172 in RPE cells, and STS treatment thus inhibited ARPE-19 cell monolayer permeability under HG condition, similar to the permeability under normal glucose (5.5 mmol glucose, NG). Moreover, we found that STS obviously prevented the colocalization of NF-κB and p300, and significantly inhibited their binding, subsequent decreased ARPE-19 cell monolayer permeability. Notably, Compound C (CC), a specific inhibitor of AMPK, blocked STS-mediated inhibition of ARPE-19 cell monolayer permeability.Conclusions: STS inhibited HG-induced RPE permeability possibly through the reduction of NF-κB activation via the AMPK/p300 pathway. The protective effects of STS were attained through the suppression of p300-mediated NF-κB acetylation and STS might be utilized for treatment of DR, in terms of preventing inflammation.