RESUMO
The pandemic caused by the worldwide spread of the coronavirus,which first appeared in 2019,has been named coronavirus disease 19 (COVID-19).More than 4.5 million deaths have been recorded due to the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),according to the World Health Organization.COVID-19 Dashboard in September 2021.Apart from the wildtype,other variations have been successfully transmitted early in the outbreak although they were not discovered until March 2020.Modifications in the SARS-CoV-2 genetic material,such as mutation and recombi-nation,have the ability to modify the viral life span,along with transitivity,cellular tropism,and symptom severity.Several processes are involved in introducing novel vaccines to the population,including vaccine manufacturing,preclinical studies,Food and Drug Administration permission or cer-tification,processing,and marketing.COVID-19 vaccine candidates have been developed by a number of public and private groups employing a variety of strategies,such as RNA,DNA,protein,and viral vectored vaccines.This comprehensive review,which included the most subsequent evidence on unique features of SARS-CoV-2 and the associated morbidity and mortality,was carried out using a systematic search of recent online databases in order to generate useful knowledge about the COVID-19 updated versions and their consequences on the disease symptoms and vaccine development.
RESUMO
The aim of this work was to study the relative ghrelin and growth hormone secretagogue receptor (GHS-R)1a gene expression in the kidney of long-term diabetic rats. Forty male Wistar albino rats were divided into four groups: C- control group, DI- one month diabetic rats group, DII- two months diabetic rats group, and DIII- three months diabetic rats group. Diabetes was induced by streptozotocin STZ (40mg/kg i.p). The rats were decapitated under ketamine anesthesia and their kidney tissues were removed. Tissue GHS-R mRNA levels, ghrelin expression, and histopathological damage scores were compared. Dilatation in the distal tubules, epithelial desquamation into the lumen of the tubules and transparent tubules showing glycogen vacuolation were observed in all the diabetic groups. Ghrelin immunoreactivity was significantly higher in group DI compared to group C, whereas in groups DII and DIII, ghrelin immunoreactivity was similar with group C. GHSR-1a mRNA level in group DIII was significantly lower than in group C. As a result, ghrelin immunoreactivity increased at the beginning of diabetes; however, with increase in the duration of diabetes ghrelin immunoreactivity approached to the control values. The expression of GHSR-1a mRNA decreased with increase in diabetes duration. It seemed that down-regulation of GHSR-1a contributed to the renal damage induced by long-term diabetes.