Metatranscriptome of human lung microbial communities in a cohort of mechanically ventilated COVID-19 Omicron patients.

The Omicron variant of the severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) infected a substantial proportion of Chinese population, and understanding the factors underlying the severity of the disease and fatality is valuable for future prevention and clinical treatment. We recruited 64 patients with invasive ventilation for COVID-19 and performed metatranscriptomic sequencing to profile host transcriptomic profiles, plus viral, bacterial, and fungal content, as well as virulence factors and examined their relationships to 28-day mortality were examined. In addition, the bronchoalveolar lavage fluid (BALF) samples from invasive ventilated hospital/community-acquired pneumonia patients (HAP/CAP) sampled in 2019 were included for comparison. Genomic analysis revealed that all Omicron strains belong to BA.5 and BF.7 sub-lineages, with no difference in 28-day mortality between them. Compared to HAP/CAP cohort, invasive ventilated COVID-19 patients have distinct host transcriptomic and microbial signatures in the lower respiratory tract; and in the COVID-19 non-survivors, we found significantly lower gene expressions in pathways related viral processes and positive regulation of protein localization to plasma membrane, higher abundance of opportunistic pathogens including bacterial Alloprevotella, Caulobacter, Escherichia-Shigella, Ralstonia and fungal Aspergillus sydowii and Penicillium rubens. Correlational analysis further revealed significant associations between host immune responses and microbial compositions, besides synergy within viral, bacterial, and fungal pathogens. Our study presents the relationships of lower respiratory tract microbiome and transcriptome in invasive ventilated COVID-19 patients, providing the basis for future clinical treatment and reduction of fatality.

Characteristics and prognostic implications of peripheral blood lymphocyte subsets in patients with anti-MDA5 antibody positive dermatomyositis-interstitial lung disease.

OBJECTIVES: To examine the characteristics of blood lymphocyte subsets in dermatomyositis-interstitial lung disease (DM-ILD) inflicted patients with positive anti-melanoma differentiation-associated gene 5 (anti-MDA5), as well as its prognosis value in this set of patients. METHODS: Data were retrospectively collected from 253 DM-ILD patients from three hospitals in China between January 2016 to January 2021. Patients were grouped into anti-MDA5 antibody positive group (MDA5+ DM-ILD) and anti-MDA5 antibody negative group (MDA5- DM-ILD) based on myositis-specific autoantibody test results. Demographic characteristics, lymphocyte subsets patterns and other clinical features were compared between the two groups. The association of lymphocyte subsets with 180-day mortality was investigated using survival analysis in MDA5+ DM-ILD. RESULTS: Out of 253 eligible patients with DM-ILD, 59 patients were anti-MDA5+ and 194 were anti-MDA5-. Peripheral blood lymphocyte count, CD3+ count, percentage of CD3+, CD3+CD4+ count, and CD3+CD8+ count was lower in MDA5+ DM-ILD than in MDA5- DM-ILD- (all P < 0.001) as well as CD3-CD19+ count (P = 0.04). In MDA5+ DM-ILD, CD3+CD8+ count ≤ 49.22 cell/µL (HR = 3.81, 95%CI [1.20,12.14]) and CD3-CD19+ count ≤ 137.64 cell/µL (HR = 3.43, 95%CI [1.15,10.24]) were independent predictors of mortality. CD3+CD8+ count ≤ 31.38 cell/µL was associated with a higher mortality risk in all DM-ILD patients (HR = 8.6, 95%CI [2.12,31.44]) after adjusting for anti-MDA5 and other clinical characteristics. CONCLUSION: Significant lymphocytes decrease was observed in MDA5+ DM-ILD patients. CD3+CD8+ cell count was associated with worse prognosis in both MDA5+ DM-ILD and all DM-ILD patients.

Analysis on Early and Late Operation Results and Risk Factors of Elderly Acute Type-A Aortic Dissection.

OBJECTIVE: To explore the early and late operation results and risk factors of elderly acute type-A aortic dissection. METHODS: The regression analysis was conducted on the data of patients diagnosed with acute type-A aortic dissection in our hospital from January 2018 to January 2020, and a total of 98 patients aged over 70 years were included in the study. The patients were listed into the early operation group (a total of 51 patients operated within 3 days after admission) and the late operation group (a total of 47 patients operated within 10 days after admission) according to the time of operation. The operation results, postoperative complications and death were compared between the two groups, and the prognosis risk factors were analyzed through Logistic multi-factor regression. RESULTS: The operative time, aortic obstruction time and extracorporeal circulation time of the late operation group were all higher than those in the early operation group (p <0.05). The postoperative complications and mortality in the late operation group (12.77%) were higher than those in the early operation group (3.92%) (p < 0.05). The Logistic multi-factor regression showed that late operation (p=0.005, OR=4.213, 95% CI=1.567~11.201), postoperative acute renal insufficiency (p=0.028, OR=3.281, 95% CI=0.937~10.283), and postoperative pulmonary infection (p=0.033, OR=1.421, 95% CI=0.417~8.329) were risk factors affecting postoperative mortality (p <0.05). CONCLUSION: The early operation can effectively reduce the postoperative complications of elderly acute type-A aortic dissection, so early operation should be performed according to the conditions of patients and hospital.

The Threshold Effects of Low-Dose-Rate Radiation on miRNA-Mediated Neurodevelopment of Zebrafish.

The biological effects and regulatory mechanisms of low-dose and low-dose-rate radiation are still rather controversial. Therefore, in this study we investigated the effects of low-dose-rate radiation on zebrafish neurodevelopment and the role of miRNAs in radiation-induced neurodevelopment. Zebrafish embryos received prolonged gamma-ray irradiation (0 mGy/h, 0.1 mGy/h, 0.2 mGy/h, 0.4 mGy/h) during development. Neurodevelopmental indicators included mortality, malformation rate, swimming speed, as well as the morphology changes of the lateral line system and brain tissue. Additionally, spatiotemporal expression of development-related miRNAs (dre-miR-196a-5p, dre-miR-210-3p, dre-miR-338) and miRNA processing enzymes genes (Dicer and Drosha) were assessed by qRT-PCR and whole mount in situ hybridization (WISH). The results revealed a decline in mortality, malformation and swimming speed, with normal histological and morphological appearance, in zebrafish that received 0.1 mGy/h; however, increased mortality, malformation and swimming speed were observed, with pathological changes, in zebrafish that received 0.2 mGy/h and 0.4 mGy/h. The expression of miRNA processing enzyme genes was altered after irradiation, and miRNAs expression was downregulated in the 0.1 mGy/h group, and upregulated in the 0.2 mGy/h and 0.4 mGy/h groups. Furthermore, ectopic expression of dre-miR-210-3p, Dicer and Drosha was also observed in the 0.4 mGy/h group. In conclusion, the effect of low-dose and low-dose-rate radiation on neurodevelopment follows the threshold model, under the regulation of miRNAs, excitatory effects occurred at a dose rate of 0.1 mGy/h and toxic effects occurred at a dose rate of 0.2 mGy/h and 0.4 mGy/h.