MHC class I links with severe pathogenicity in C57BL/6N mice infected with SARS-CoV-2/BMA8.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes non-symptomatic infection, mild influenza-like symptoms to pneumonia, severe acute respiratory distress syndrome, and even death, reflecting different clinical symptoms of viral infection. However, the mechanism of its pathogenicity remains unclear. Host-specific traits have a breakthrough significance for studying the pathogenicity of SARS-CoV-2. We previously reported SARS-CoV-2/BMA8, a mouse-adapted strain, was lethal to aged BALB/c mice but not to aged C57BL/6N mice. Here, we further investigate the differences in pathogenicity of BMA8 strain against wild-type aged C57BL/6N and BALB/c mice. METHODS: Whole blood and tissues were collected from mice before and after BMA8 strain infection. Viral replication and infectivity were assessed by detection of viral RNA copies and viral titers; the degree of inflammation in mice was tested by whole blood cell count, ELISA and RT-qPCR assays; the pathogenicity of SARS-CoV-2/BMA8 in mice was measured by Histopathology and Immunohistochemistry; and the immune level of mice was evaluated by flow cytometry to detect the number of CD8+ T cells. RESULTS: Our results suggest that SARS-CoV-2/BMA8 strain caused lower pathogenicity and inflammation level in C57BL/6N mice than in BALB/c mice. Interestingly, BALB/c mice whose MHC class I haplotype is H-2Kd showed more severe pathogenicity after infection with BMA8 strain, while blockade of H-2Kb in C57BL/6N mice was also able to cause this phenomenon. Furthermore, H-2Kb inhibition increased the expression of cytokines/chemokines and accelerated the decrease of CD8+ T cells caused by SARS-CoV-2/BMA8 infection. CONCLUSIONS: Taken together, our work shows that host MHC molecules play a crucial role in the pathogenicity differences of SARS-CoV-2/BMA8 infection. This provides a more profound insight into the pathogenesis of SARS-CoV-2, and contributes enlightenment and guidance for controlling the virus spread.

The Implementation and Role of Antigen Rapid Test for COVID-19 in Hemodialysis Units.

As we move into the third year with COVID-19, many countries have attempted to manage the disease as an endemic. However, this is limited by the disease's morbidity and mortality, the emergence of new strains, and the effectiveness of the vaccine. This brief report describes, evaluates, and discusses the implementation of regular antigen rapid tests (ARTs) for COVID-19 in hemodialysis units. We introduced ARTs during the surge in our hemodialysis units. As compliance with the test was mandatory by regulatory requirements, we surveyed patients and caregivers to measure their acceptability, appropriateness, and feasibility of the ART's implementation. Acceptability measured confidence and level of comfort when performing ART tests, while appropriateness measured the perception of the necessity of ARTs, safety in the dialysis unit with the implementation of ARTs, and understanding using a Likert scale. Feasibility measured the perception of the timely start of dialysis treatment and the convenience of the test. Our survey found that ARTs were acceptable to 98% of patients and caregivers, with the majority reporting no discomfort. The majority of the patients agreed that ARTs were appropriate and feasible. We reported successful ART implementation in a healthcare setting with no false-positive or transmission within the unit during this period. Nevertheless, the long-term implementation outcome will require further evaluation.

Deep Learning for Detecting COVID-19 Using Medical Images.

The global spread of COVID-19 (also known as SARS-CoV-2) is a major international public health crisis [...].

Effects of COVID-19 vaccination status, vaccine type, and vaccination interval on IVF pregnancy outcomes in infertile couples.

PURPOSE: This study aimed to explore whether the coronavirus disease (COVID-19) vaccination of both partners in infertile couples, different types of COVID-19 vaccines, and the interval between complete vaccination and oocyte retrieval or embryo transfer (ET) affect the quality of embryos and pregnancy rates in in vitro fertilization (IVF). METHODS: This was a prospective cohort study, comprising 735 infertile couples conducted between December 6, 2021, and March 31, 2022, in a single university hospital-based IVF center. The patients were divided into different groups according to the vaccination status of both partners in infertile couples, type of vaccine, and interval between complete vaccination and IVF treatment. The embryo quality and pregnancy rates were compared among different groups. RESULTS: The results showed that embryo quality and pregnancy rates had no significant differences among different groups. The multivariate regression model showed that the vaccination status of both infertile couples, types of vaccines, and intervals had no significant effects on the clinical pregnancy rate. CONCLUSIONS: The vaccination status of both partners in infertile couples, different types of vaccines, and time intervals have no effect on embryo quality and pregnancy rates in IVF. This is the first study to compare the vaccination status of both partners in infertile couples and the impact of different vaccine types on pregnancy rates and embryo quality in detail. Our findings provide evidence of vaccine safety for infertile couples wishing to undergo IVF treatment. This evidence is crucial for decision-making by clinicians and policymakers involved in IVF cycles.

Stigmatizing Attitudes Toward COVID-19 Among Patients, Their Relatives and Healthy Residents in Zhangjiajie.

Introduction: In July 2021, Zhangjiajie City became the new epicenter of the COVID-19 outbreak. Aside from the physical manifestations of COVID-19, patients are also victims of severe social stigmatization. Stigma affects not only COVID-19 patients or survivors, but also individuals associated with them. This study aims to describe and assess the COVID-19-related stigma between patients, their relatives, and healthy local residents. Methods: The study included 43 COVID-19 patients, 68 relatives, and 75 healthy residents from Zhangjiajie. Demographic data was collected, including gender, age, marital status, and educational level. Stigma attitudes toward COVID-19 were measured using the Stigma Scale and Social Distance Scale. Frequencies and percentages were described for each item of the scales, and differences among the three groups were examined using the chi-square test. Results: With regards to personal and perceived stigma, most participants agreed that patients with COVID-19 "could snap out of the problem" and that "they were dangerous." For social distance, over 30% of participants from the three groups agreed with the item "unwillingness to marry into the family of someone with COVID-19." In all groups, there were significant statistical differences in the belief that "the problem is not a real medical illness" and the desire to "spend the evening socializing." Conclusion: Although the outbreak was well-contained in Zhangjiajie, stigmatizing attitudes toward COVID-19 and desire for social distance to such patients were common among patients, their relatives and healthy local residents. Our study's results suggest that public education, anti-stigma interventions, and policies are necessary for people living in Zhangjiajie in order to effectively curtail the spread of COVID-19 and provide a useful strategy for a tourist city like Zhangjiajie to recover sooner from economic decline.

Multi-branch fusion auxiliary learning for the detection of pneumonia from chest X-ray images.

Lung infections caused by bacteria and viruses are infectious and require timely screening and isolation, and different types of pneumonia require different treatment plans. Therefore, finding a rapid and accurate screening method for lung infections is critical. To achieve this goal, we proposed a multi-branch fusion auxiliary learning (MBFAL) method for pneumonia detection from chest X-ray (CXR) images. The MBFAL method was used to perform two tasks through a double-branch network. The first task was to recognize the absence of pneumonia (normal), COVID-19, other viral pneumonia and bacterial pneumonia from CXR images, and the second task was to recognize the three types of pneumonia from CXR images. The latter task was used to assist the learning of the former task to achieve a better recognition effect. In the process of auxiliary parameter updating, the feature maps of different branches were fused after sample screening through label information to enhance the model's ability to recognize case of pneumonia without impacting its ability to recognize normal cases. Experiments show that an average classification accuracy of 95.61% is achieved using MBFAL. The single class accuracy for normal, COVID-19, other viral pneumonia and bacterial pneumonia was 98.70%, 99.10%, 96.60% and 96.80%, respectively, and the recall was 97.20%, 98.60%, 96.10% and 89.20%, respectively, using the MBFAL method. Compared with the baseline model and the model constructed using the above methods separately, better results for the rapid screening of pneumonia were achieved using MBFAL.

Australia's Crisis Responses During COVID-19: The Case of International Students

Since the outbreak of the COVID-19 pandemic, the global international education sector has been fraught with multiple, intensifying stressors, which have severely affected international students' lives and study. Host government policies on international education can make a critical difference for this vulnerable population during the pandemic. Australia's crisis response policies during the pandemic have been closely tracked and vigorously discussed amongst Chinese international students. This study examines how Australia's crisis responses addressed the needs of international students during the pandemic, and how these policies impacted Chinese international students' experiences and perceptions of studying in Australia. We collected qualitative data through interviews with Chinese international students, parents and migration agents, virtual ethnography on WeChat, and analysis of Australia's policy responses. Our thematic analysis highlights participants' experiences and views of Australia's crisis responses in the four areas of financing, third-country transit, visas and immigration, and pandemic management. We discuss these findings in relation to the historical context of Australia's higher education funding reforms during the 1980s and 1990s.

Substance and Internet use during the COVID-19 pandemic in China.

The coronavirus disease 2019 (COVID-19) has adversely influenced human physical and mental health, including emotional disorders and addictions. This study examined substance and Internet use behavior and their associations with anxiety and depression during the COVID-19 pandemic. An online self-report questionnaire was administered to 2196 Chinese adults between February 17 and 29, 2020. The questionnaire contained the seven-item Generalized Anxiety Disorder Scale (GAD-7) and Patient Health Questionnaire (PHQ-9), questions on demographic information, and items about substance and Internet use characteristics. Our results revealed that males consumed less alcohol (p < 0.001) and areca-nut (p = 0.012) during the pandemic than before the pandemic. Age, gender, education status, and occupation significantly differed among increased substance users, regular substance users, and nonsubstance users. Time spent on the Internet was significantly longer during the pandemic (p < 0.001) and 72% of participants reported increased dependence on the Internet. Compared to regular Internet users, increased users were more likely to be younger and female. Multiple logistic regression analysis revealed that age <33 years (OR = 2.034, p < 0.001), increased substance use (OR = 3.439, p < 0.001), and increased Internet use (OR = 1.914, p < 0.001) were significantly associated with depression. Moreover, anxiety was significantly related to female gender (OR = 2.065, p < 0.001), "unmarried" status (OR = 1.480, p = 0.017), nonstudents (OR = 1.946-3.030, p = 0.001), and increased substance use (OR = 4.291, p < 0.001). Although there was a significant decrease in social substance use during the pandemic, more attention should be paid to increased Internet use. Increased Internet use was significantly associated with both anxiety and depression, and increased substance use was related to depression. Professional support should be provided to vulnerable individuals to prevent addiction.

The scRNA-seq Expression Profiling of the Receptor ACE2 and the Cellular Protease TMPRSS2 Reveals Human Organs Susceptible to SARS-CoV-2 Infection.

COVID-19 patients always develop multiple organ dysfunction syndromes other than lungs, suggesting the novel virus SARS-CoV-2 also invades other organs. Therefore, studying the viral susceptibility of other organs is important for a deeper understanding of viral pathogenesis. Angiotensin-converting enzyme II (ACE2) is the receptor protein of SARS-CoV-2, and TMPRSS2 promotes virus proliferation and transmission. We investigated the ACE2 and TMPRSS2 expression levels of cell types from 31 organs to evaluate the risk of viral infection using single-cell RNA sequencing (scRNA-seq) data. For the first time, we found that the gall bladder and fallopian tube are vulnerable to SARS-CoV-2 infection. Besides, the nose, heart, small intestine, large intestine, esophagus, brain, testis, and kidney are also identified to be high-risk organs with high expression levels of ACE2 and TMPRSS2. Moreover, the susceptible organs are grouped into three risk levels based on the ACE2 and TMPRSS2 expression. As a result, the respiratory system, digestive system, and urinary system are at the top-risk level for SARS-CoV-2 infection. This study provides evidence for SARS-CoV-2 infection in the human nervous system, digestive system, reproductive system, respiratory system, circulatory system, and urinary system using scRNA-seq data, which helps in the clinical diagnosis and treatment of patients.

The evaluation of sleep disturbances for Chinese frontline medical workers under the outbreak of COVID-19.

OBJECTIVE: To evaluate sleep disturbances of Chinese frontline medical workers (FMW) under the outbreak of coronavirus disease 2019 (COVID-19), and make a comparison with non-FMW. METHODS: The medical workers from multiple hospitals in Hubei Province, China, volunteered to participate in this cross-sectional study. An online questionnaire, including Pittsburgh Sleep Quality Index (PSQI), Athens Insomnia Scale (AIS) and Visual Analogue Scale (VAS), was used to evaluate sleep disturbances and mental status. Sleep disturbances were defined as PSQI>6 points or/and AIS>6 points. We compared the scores of PSQI, AIS, anxiety and depression VAS, as well as prevalence of sleep disturbances between FMW and non-FMW. RESULTS: A total of 1306 subjects (801 FMW and 505 non-FMW) were enrolled. Compared to non-FMW, FMW had significantly higher scores of PSQI (9.3 ± 3.8 vs 7.5 ± 3.7; P < 0.001; Cohen's d = 0.47), AIS (6.9 ± 4.3 vs 5.3 ± 3.8; P < 0.001; Cohen's d = 0.38), anxiety (4.9 ± 2.7 vs 4.3 ± 2.6; P < 0.001; Cohen's d = 0.22) and depression (4.1 ± 2.5 vs 3.6 ± 2.4; P = 0.001; Cohen's d = 0.21), as well as higher prevalence of sleep disturbances according to PSQI > 6 points (78.4% vs 61.0%; relative risk [RR] = 1.29; P < 0.001) and AIS > 6 points (51.7% vs 35.6%; RR = 1.45; P < 0.001). CONCLUSION: FMW have higher prevalence of sleep disturbances and worse sleep quality than non-FMW. Further interventions should be administrated for FMW, aiming to maintain their healthy condition and guarantee their professional performance in the battle against COVID-19.