Benign course and clinical features of COVID-19 in hospitalised febrile infants up to 60 days old.

AIM: Minimal data exist regarding the severity of COVID-19 in febrile infants under 60 days old. This multicentre prospective study explored the clinical course and outcomes of this hospitalised patient population, as, to date, the best approach has not been specifically addressed. METHODS: This study focused on the clinical features, laboratory parameters and outcomes of febrile infants up to 60 days old who tested positive for the virus and were hospitalised in Israel from March 2020 to January 2021. The data were extracted from a real-time prospective surveillance network for COVID-19 that includes 20 of the country's 26 hospitals. RESULTS: We identified 75 febrile young infants (60% female) with COVID-19 at a median age of 28 days (range 8-56 days). Of these, 84% had an unremarkable medical history, 29% had respiratory symptoms, and 96% had a mild illness. The Rochester criteria showed that 44% were considered at high-risk for serious bacterial infections, and we found that eight infants actually had concomitant bacterial infections. Outcomes were excellent, and no complications or fatalities were reported. CONCLUSION: The excellent outcomes of young febrile infants with COVID-19 closely resembled other respiratory viral aetiologies of fever in this age group, and there were no fatalities.

Dysregulation of wound healing mechanisms in diabetes and the importance of negative pressure wound therapy (NPWT).

Diabetes is a serious disease with severe side effects and comorbidities. Diabetic foot with its chronic nonhealing ulcers, or diabetic foot ulcers, as they are commonly called, can be devastating, even leading to amputation. Many therapies exist to assist and improve wound healing. One exciting discovery is the use of negative pressure wound therapy (NPWT) as an adjunct to standard treatment. Few studies have substantively explored the molecular mechanisms of NPWT and why we see improved wound healing, a concept that demands more research. The following commentary summarizes the current literature regarding NPWT as well as some of the vast body of work that focuses on the physiologic mechanisms of wound healing in diabetics in general.

Stem Cells for Diabetes Complications: A Future Potential Cure.

Long-standing diabetes leads to structural and functional alterations in both the micro- and the macrovasculature. Designing therapies to repair these abnormalities present unique and sophisticated challenges. Vascular endothelial cells are the primary cells damaged by hyperglycemia-induced adverse effects. Vascular stem cells that give rise to endothelial progenitor cells and mesenchymal progenitor cells represent an attractive target for cell therapy for diabetic patients. In this review, we shed light on challenges and recent advances surrounding stem cell therapies for diabetes vascular complications and discuss limitations for their clinical adoption.

Inducible NO synthase dependent S-nitrosylation and activation of arginase1 contribute to age-related endothelial dysfunction.

Endothelial function is impaired in aging because of a decrease in NO bioavailability. This may be, in part, attributable to increased arginase activity, which reciprocally regulates NO synthase (NOS) by competing for the common substrate, L-arginine. However, the high Km of arginase (>1 mmol/L) compared with NOS (2 to 20 micromol/L) seemingly makes direct competition for substrate unlikely. One of the mechanisms by which NO exerts its effects is by posttranslational modification through S-nitrosylation of protein cysteines. We tested the hypothesis that arginase1 activity is modulated by this mechanism, which serves to alter its substrate affinity, allowing competition with NOS for L-arginine. We demonstrate that arginase1 activity is altered by S-nitrosylation, both in vitro and ex vivo. Furthermore, using site-directed mutagenesis we demonstrate that 2 cysteine residues (C168 and C303) are able to undergo nitrosylation. S-Nitrosylation of C303 stabilizes the arginase1 trimer and reduces its Km value 6-fold. Finally, arginase1 nitrosylation is increased (and thus its Km decreased) in blood vessels from aging rats, likely contributing to impaired NO bioavailability and endothelial dysfunction. This is mediated by inducible NOS, which is expressed in the aging endothelium. These findings suggest that S-nitrosylated arginase1 can compete with NOS for L-arginine and contribute to endothelial dysfunction in the aging cardiovascular system.