Purpose A pilot study to describe histopathological features of penile tissue of patients who recovered from symptomatic COVID-19 infection and subsequently developed severe erectile dysfunction (ED). Materials and Methods Penile tissue was collected from patients undergoing surgery for penile prosthesis for severe ED. Specimens were obtained from two men with a history of COVID-19 infection and two men with no history of infection. Specimens were imaged with TEM and H&E staining. RT-PCR was performed from corpus cavernosum biopsies. The tissues collected were analyzed for endothelial Nitric Oxide Synthase (eNOS, a marker of endothelial function) and COVID-19 spike-protein expression. Endothelial progenitor cell (EPC) function was assessed from blood samples collected from COVID-19 (+) and COVID-19 (−) men. Results TEM showed extracellular viral particles ~100 nm in diameter with peplomers (spikes) near penile vascular endothelial cells of the COVID-19 (+) patients and absence of viral particles in controls. PCR showed presence of viral RNA in COVID-19 (+) specimens. eNOS expression in the corpus cavernosum of COVID-19 (+) men was decreased compared to COVID-19 (−) men. Mean EPC levels from the COVID-19 (+) patients were substantially lower compared to mean EPCs from men with severe ED and no history of COVID-19. Conclusions Our study is the first to demonstrate the presence of the COVID-19 virus in the penis long after the initial infection in humans. Our results also suggest that widespread endothelial cell dysfunction from COVID-19 infection can contribute to ED. Future studies will evaluate novel molecular mechanisms of how COVID-19 infection leads to ED.

Object Segmental nerve defects pose a daunting clinical challenge, as peripheral nerve injury studies have established that there is a critical nerve gap length for which the distance cannot be successfully bridged with current techniques. Construction of a neural prosthesis filled with Schwann cells (SCs) could provide an alternative treatment to successfully repair these long segmental gaps in the peripheral nervous system. The object of this study was to evaluate the ability of autologous SCs to increase the length at which segmental nerve defects can be bridged using a collagen tube. Methods The authors studied the use of absorbable collagen conduits in combination with autologous SCs (200,000 cells/μl) to promote axonal growth across a critical size defect (13 mm) in the sciatic nerve of male Fischer rats. Control groups were treated with serum only–filled conduits of reversed sciatic nerve autografts. Animals were assessed for survival of the transplanted SCs as well as the quantity of myelinated axons in the proximal, middle, and distal portions of the channel. Results Schwann cell survival was confirmed at 4 and 16 weeks postsurgery by the presence of prelabeled green fluorescent protein–positive SCs within the regenerated cable. The addition of SCs to the nerve guide significantly enhanced the regeneration of myelinated axons from the nerve stump into the proximal (p < 0.001) and middle points (p < 0.01) of the tube at 4 weeks. The regeneration of myelinated axons at 16 weeks was significantly enhanced throughout the entire length of the nerve guide (p < 0.001) as compared with their number in a serum–only filled tube and was similar in number compared with the reversed autograft. Autotomy scores were significantly lower in the animals whose sciatic nerve was repaired with a collagen conduit either without (p < 0.01) or with SCs (p < 0.001) when compared with a reversed autograft. Conclusions The technique of adding SCs to a guidance channel significantly enhanced the gap distance that can be repaired after peripheral nerve injury with long segmental defects and holds promise in humans. Most importantly, this study represents some of the first essential steps in bringing autologous SC-based therapies to the domain of peripheral nerve injuries with long segmental defects.

The inflammatory response appears to play a critical role in clotting in which neutrophil extracellular traps (NETs) are the major drivers of thrombosis in acute ischemic stroke (AIS). The inflammasome is an innate immune complex involved in the activation of interleukin (IL)-18 and IL-1β through caspase-1, but whether the inflammasome plays a role in NETosis in AIS remains poorly understood. Here we assessed the levels of inflammasome signaling proteins in NETs and their association with clinical and procedural outcomes of mechanical thrombectomy for AIS. Electron microscopy and immunofluorescence indicate the presence of NETs in thrombi of patients with AIS. Moreover, the inflammasome signaling proteins caspase-1 and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) were also present in clots associated with the marker of NETosis citrullinated histone 3H (CitH3). Analysis of protein levels by a simple plex assay show that caspase-1, ASC and interleukin (IL)-1β were significantly elevated in clots when compared to plasma of AIS patients and healthy controls, while IL-18 levels were lower. Moreover, multivariate analyses show that IL-1β levels in clots contribute to the number of passes to achieve complete recanalization, and that ASC, caspase-1 and IL-18 are significant contributors to time to recanalization. Thus, inflammasome proteins are elevated in NETs present in thrombi of patients with AIS that contribute to poor outcomes following stroke.