SARS-CoV-2 in patients with cancer: possible role of mimicry of human molecules by viral proteins and the resulting anti-cancer immunity

A few reports suggest that molecular mimicry can have a role in determining the more severe and deadly forms of COVID-19, inducing endothelial damage, disseminated intravascular coagulation, and multiorgan failure. Heat shock proteins/molecular chaperones can be involved in these molecular mimicry phenomena. However, tumor cells can display on their surface heat shock proteins/molecular chaperones that are mimicked by SARS-CoV-2 molecules (including the Spike protein), similarly to what happens in other bacterial or viral infections. Since molecular mimicry between SARS-CoV-2 and tumoral proteins can elicit an immune reaction in which antibodies or cytotoxic cells produced against the virus cross-react with the tumor cells, we want to prompt clinical studies to evaluate the impact of SARS-CoV-2 infection on prognosis and follow up of various forms of tumors. These topics, including a brief historical overview, are discussed in this paper.     

An analysis of maternal deaths in British Columbia: 1963 to 1970

There were 132 maternal deaths in British Columbia in the years 1963 to 1970. The mean maternal mortality rate for these eight years was 0.317. Sixty of these deaths (45.5%) were due to direct obstetrical causes. Indirect and nonrelated deaths accounted for 21.2 and 33.3% of the total, respectively. The most common causes of direct obstetrical deaths were hemorrhage, infection and vascular accidents, in that order; pre-eclampsia ranked a distant fourth. Ninety-five percent of direct obstetrical deaths were probably avoidable. Approximately 27% of all direct obstetrical deaths were abortion-related. Hemorrhage continues to be a major problem, in particular among the native Indian women of the province.If further reduction in maternal mortality is to be achieved, obstetrical hemorrhage must be better managed and deaths due to abortions reduced. Future studies should reveal if the liberalized abortion laws will assist in the realization of the latter goal.     

Rheological properties of cross-linked hyaluronan-gelatin hydrogels for tissue engineering

Hydrogels that mimic the natural extracellular matrix (ECM) are used in three-dimensional cell culture, cell therapy, and tissue engineering. A semi-synthetic ECM based on cross-linked hyaluronana offers experimental control of both composition and gel stiffness. The mechanical properties of the ECM in part determine the ultimate cell phenotype. We now describe a rheological study of synthetic ECM hydrogels with storage shear moduli that span three orders of magnitude, from 11 to 3 500 Pa, a range important for engineering of soft tissues. The concentration of the chemically modified HA and the cross-linking density were the main determinants of gel stiffness. Increase in the ratio of thiol-modified gelatin reduced gel stiffness by diluting the effective concentration of the HA component.