Stuck between a rock and a hard place: The clinical conundrum of managing cardiac surgical patients during the SARS-CoV-2 pandemic

Deferring nonemergent cardiac surgery became the strategy of choice for several international healthcare systems afflicted by high case burdens of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2/COVID-19) to both conserve valuable healthcare resources and protect patients from possible exposure. Missing from the available dataset to help guide policy development has been a clear understanding of the extent to which COVID-19 infection modulates cardiac surgery outcomes. In their investigation, Bonalumi et al. uncovered an inpatient COVID-19 positivity rate of almost 10 times higher than that of the general Italian population, as well as a mortality rate over 20 times higher amongst cardiac surgery patients with perioperative COVID-19 infection compared to those COVID-negative. While the summation of available evidence points to the serious consideration cardiac surgeons must give to delaying surgeries during the COVID-19 pandemic, recognition must be given to the risks that postponing cardiac surgery may have on patient outcomes. Emerging data is beginning to demonstrate the efficacy of vaccination in preventing postoperative COVID-19 infection and morbidity.     

Placental extracts regulate melanin synthesis in normal human melanocytes with alterations of mitochondrial respiration

Placental extracts have been widely used as skin lightening agents in the Japanese cosmetic market. Here, we show that placental extracts contain factors that can decrease or increase melanin synthesis by normal human melanocytes in vitro in possible association with mitochondrial respiration. When normal human melanocytes were treated with a whole porcine placental extract, melanin synthesis was decreased. In contrast, a porcine placental extract in which exudates and insoluble materials including lipids had been removed increased melanin synthesis. In addition, the amount of tyrosinase, the enzyme critical for melanin synthesis, changed in accordance with the alteration of melanin synthesis. Interestingly, the amount of manganese‐dependent superoxide dismutase (MnSOD), a mitochondrial‐resident antioxidant enzyme, was increased when melanin synthesis was decreased by the whole placental extract. Mitochondrial respiration and glycolysis also changed following treatment with the placental extracts. These results suggest that placental extracts contain factors that can increase or decrease melanin synthesis by normal human melanocytes and that mitochondrial function may be associated with the placental extract‐induced regulation of melanogenesis.     

Cryopreservation of vascular mixed cell for tissue engineering in cardiovascular surgery]

Tissue engineering (TE) is a new discipline that offers the potential to create replacement structures from autologous cells and biodegradable polymer scaffold. Various vascular and valvular grafts have been tried to create with this TE approach. In clinical use of this technique, harvested and cultured cells have to keep viability until implantation as tissue engineered tissue. But few research for cryopreservation of vascular mixed cells has been performed. So, we investigated the proper method for cryopreservation of vascular mixed cells harvested from femoral artery and vein of dogs. Cells were cultured and divide into three groups, A: cryopreserving in 5% dimethylsulfoxide (DMSO), hydroxyethyl starch (HES), and fetal bovine serum (FBS) with -80 degrees C freezer; B: cryopreserving in 10% DMSO and FBS with programmed freezer; C: control (continuous culture in media). After rapid thawing at 40 degrees C, group A showed higher viability than group B with flow cytometry. The results means that vascular mixed cells can be successfully cryopreserved in the DMSO/HES mixture simply and inexpensively, without rate controlled freezing.     

Three novel connexin26 gene mutations in autosomal recessive non-syndromic deafness.

Since the first identification of an association between mutations in the connexin26 (Cx26) gene and autosomal recessive non-syndromic deafness it has been shown that several mutations in this gene cause recessive, sporadic, and dominant non-syndromic deafness. Three novel mutations in the Cx26 gene were identified in four of 20 Japanese families with autosomal recessive non-syndromic deafness. Seven of 40 chromosomes contained a 233delC allele, while Tyr136Stop (408C-->A) and Gly45Glu (134G-->A) were detected in two of 40 chromosomes, respectively. These mutations were not found in chromosomes in cases of sporadic congenital deafness (0/60) or in control groups (0/100). This indicates that 27.5% (11/40 chromosomes) of cases of autosomal recessive non-syndromic deafness among the Japanese are caused by mutations in the Cx26 gene.