Background Since SARS‐CoV‐2 infection was first identified in December 2019, the novel coronavirus‐induced pneumonia COVID‐19 spread rapidly and triggered a global pandemic. Recent bioinformatics evidence suggests that angiotensin converting enzyme 2—the main cell entry target of SARS‐CoV‐2—is predominantly enriched in spermatogonia, Leydig and Sertoli cells, which suggests the potential vulnerability of the male reproductive system to SARS‐CoV‐2 infection. Objectives To identify SARS‐CoV‐2 RNA in seminal plasma and to determine semen characteristics from male patients in the acute and recovery phases of infection. Methods From February 26 to April 2, 2020, 23 male patients with COVID‐19 were recruited. The clinical characteristics, laboratory findings and chest computed tomography scans of all patients were recorded in detail. We also investigated semen characteristics and the viral RNA load in semen from these patients in the acute and recovery phases of SARS‐CoV‐2 infection using approved methods. Results The age range of the 23 patients was 20–62 years. All patients tested negative for SARS‐CoV‐2 RNA in semen specimens. Among them, the virus had been cleared in 11 patients, as they tested negative. The remaining 12 patients tested negative for SARS‐CoV‐2 RNA in semen samples, but were positive in sputum and fecal specimens. The median interval from diagnosis to providing semen samples was 32 days, when total sperm counts, total motile sperm counts and sperm morphology of the patients were within normal ranges. Discussion and Conclusion In this cohort of patients with a recent infection or recovering from COVID‐19, there was no SARS‐CoV‐2 RNA detected in semen samples, which indicates the unlikely possibility of sexual transmission through semen at about 1 month after first detection.

A new method for protein extraction from yeast Saccharomyces cerevisiae cells is described. This method involves the use of LiAc and NaOH to enhance the permeability of yeast cell wall prior to protein extraction with SDS-PAGE sample buffer. It was safe and efficient compared to other methods reported so far in the literature. The proteins extracted with this new method retained their immunoreactive properties and are suitable for most applications in molecular biology studies.

Data concerning the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic and paucisymptomatic patients are lacking. We report a 3-family cluster of infections involving asymptomatic and paucisymptomatic transmission. Eight of 15 (53%) members from 3 families were confirmed with SARS-CoV-2 infection. Of 8 patients, 3 were asymptomatic and 1 was paucisymptomatic. An asymptomatic mother transmitted the virus to her son, and a paucisymptomatic father transmitted the virus to his 3-month-old daughter. SARS-CoV-2 was detected in the environment of 1 household. The complete genomes of SARS-CoV-2 from the patients were > 99.9% identical and were clustered with other SARS-CoV-2 sequences reported from China and other countries.

Low back pain (LBP) is a major musculoskeletal disorder and the socioeconomic problem with a high prevalence that mainly involves intervertebral disc (IVD) degeneration, characterized by progressive nucleus pulposus (NP) cell death and the development of an inflammatory microenvironment in NP tissue. Excessively accumulated cytosolic DNA acts as a damage-associated molecular pattern (DAMP) that is monitored by the cGAS-STING axis to trigger the immune response in many degenerative diseases. NLRP3 inflammasome-dependent pyroptosis is a type of inflammatory programmed death that promotes a chronic inflammatory response and tissue degeneration. However, the relationship between the cGAS-STING axis and NLRP3 inflammasome-induced pyroptosis in the pathogenesis of IVD degeneration remains unclear. Here, we used magnetic resonance imaging (MRI) and histopathology to demonstrate that cGAS, STING, and NLRP3 are associated with the degree of IVD degeneration. Oxidative stress induced cGAS-STING axis activation and NLRP3 inflammasome-mediated pyroptosis in a STING-dependent manner in human NP cells. Interestingly, the canonical morphological and functional characteristics of mitochondrial permeability transition pore (mPTP) opening with the cytosolic escape of mitochondrial DNA (mtDNA) were observed in human NP cells under oxidative stress. Furthermore, the administration of a specific pharmacological inhibitor of mPTP and self-mtDNA cytosolic leakage effectively reduced NLRP3 inflammasome-mediated pyroptotic NP cell death and microenvironmental inflammation in vitro and degenerative progression in a rat disc needle puncture model. Collectively, these data highlight the critical roles of the cGAS-STING-NLRP3 axis and pyroptosis in the progression of IVD degeneration and provide promising therapeutic approaches for discogenic LBP.