Advances in Virology最新文献

Ionised active water S-100® has been proposed as an original solution for use in dermocosmetics and for the treatment of wounds such as burns and atopic dermatitis. Among the mechanisms of action that are not completely understood, an antimicrobial activity would appear to be important. In the context of the COVID-19 pandemic, we assessed the inactivating efficacy of this solution on SARS-CoV-2 based on the recommendations of the NF-EN-14476+A2 standard. The tests carried out demonstrated that ionised active water S-100® 40% has a virucidal activity on SARS-CoV-2 which is at least 3.1 log after a contact time of 30 seconds and 3.5 log after two minutes at 20°C under clean conditions. Assays were also performed at 4°C and 37°C, and the results obtained are identical to those obtained at 20°C. This demonstration of the virucidal effect of ionised water against SARS-CoV-2 paves the way for the development of usage as an alternative disinfectant in SARS-CoV-2 control.

Cytokine storm is one of the causative deaths in a patient with severe acute respiratory syndrome. This study aimed at evaluating the prophylaxis effect of quercetin complexes with zinc and buffered ascorbic acid upon cytokine storm induction in mice and identifying the complex's acute toxicity. Mice were randomly divided into three groups: group A, control group, received 0.9% normal saline; group B received 100 mg/kg of the complex one hour before lipopolysaccharide (LPS) administration; and group C received the LPS IP 5 mg/kg. Then, levels of interleukin 1 and interleukin 6 were measured in the serum, and lung and kidney tissues were investigated for any changes that may have happened. Thirty mice were used to investigate the acute toxicity; mice were distributed into six groups: one control group and five treated groups; then several serial dilutions from the complex have been prepared for different concentrations from 5 g/kg to 0.312 g/kg. The animals were observed for 14 days. The LD₅₀ was deduced by the straight-line equation calculated from the dose-response curve. The results in this study showed that group A had no significant tissue change. LPS group C showed tissue damage in the lung and kidney, which significantly prevented by the pretreated complex in group B. Moreover, the complex's acute toxicity value (LD₅₀) was 655 mg/kg. In conclusion, the complex has significantly ameliorated LPS-induced acute lung and kidney injury, largely through suppression of inflammation; the large lethal dose value may make the complex have a promising therapeutic effect in the prevention of cytokine storm.

Serious infection with respiratory syncytial virus (RSV) is associated with high risk in infants, children, and elderly. There is currently no approved vaccine against RSV infection, and the only available prevention is immunoprophylaxis utilized in high-risk infants, leaving the elderly without many options. In the elderly, the chronic low-grade inflammatory state of the body can play a significant role during infection. The cotton rat and mouse have emerged as the preferred small animal models to study RSV infection in the elderly. These animal models of aging have shown an age-dependent time course for clearance of virus correlating with a significantly diminished cytotoxic T lymphocyte and humoral immune response in old animals compared to adult animals. In addition, protection through vaccination is reduced in aging rodents. These results mirror the findings in humans. In mice and cotton rats, treatment with ibuprofen, a nonselective nonsteroidal anti-inflammatory drug (NSAID), to decrease the chronic low-grade inflammation of the elderly immune system has proven successful in restoring the function of cytotoxic lymphocytes. While more research is required, these treatment types promise a beneficial effect in addition to a putative vaccine. Choosing an appropriate animal model to study RSV infection in the aging immune system is essential to benefit the growing population of elderly in the world. This review focuses on the current research of RSV infection in the cotton rat and mouse as model systems for an aging immune system.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the cause of coronavirus disease 19 (COVID-19), has been rapidly spreading since December 2019, and within a few months, it turned out to be a global pandemic. The disease affects primarily the lungs, but its pathogenesis spreads to other organs as well. However, its mortality rates vary, and in the majority of infected people, there are no serious consequences. Many factors including advanced age, preexisting health conditions, and genetic predispositions are believed to exacerbate outcomes of COVID-19. The virus contains several structural proteins including the spike (S) protein with subunits for binding, fusion, and internalization into host cells following interaction with host cell receptors and proteases (ACE2 and TMPRSS2, respectively) to cause the subsequent pathology. Although the pandemic has spread into all countries, most of Africa is thought of as having relatively less prevalence and mortality. Several hypotheses have been forwarded as reasons for this and include warmer weather conditions, vaccination with BCG (i.e., trained immunity), and previous malaria infection. From genetics or metabolic points of view, it has been proposed that most African populations could be protected to some degree because they lack some genetic susceptibility risk factors or have low-level expression of allelic variants, such as ACE2 and TMPRSS2 that are thought to be involved in increased infection risk or disease severity. The frequency of occurrence of α-1 antitrypsin (an inhibitor of a tissue-degrading protease, thereby protecting target host tissues including the lung) deficiency is also reported to be low in most African populations. More recently, infections in Africa appear to be on the rise. In general, there are few studies on the epidemiology and pathogenesis of the disease in African contexts, and the overall costs and human life losses due to the pandemic in Africa will be determined by all factors and conditions interacting in complex ways.