Analysis of clinical characteristics and warning factors in SARS-CoV-2 variants infection / 中国热带医学

@#Abstract: Objective To investigate the influence of the variation of SARS-CoV-2 on the clinical feature, and to provide early warning signs for the variation of SARS-CoV-2 in clinical work. Methods From Jan 2, 2021 to Jun 30, 2021, a total of 105 COVID-19 patients were included in the study using a case-control method. Nasal swab samples were collected from the study subjects, the viral genes were sequenced, and patients were divided into Delta variant group and non-Delta variant group according to their gene sequences. Clinically relevant data were collected from the two groups, and indicators such as days of hospitalization, age distribution, lymphocytes, neutrophils, B lymphocytes, NK cells, IL-4, and IL-10 were compared; subgroup analysis was performed based on the number of days of viral negativity in the study subjects as the basis for grouping, and differences in immunological characteristics were compared, including lymphocytes, neutrophils, B lymphocytes, NK cells, IL-4, IL-10, etc. Results The theoretical hospitalization days of Delta variant group were (22.2±8.33) d, which were significantly longer than (17.6±10.50) d of non-Delta variant group (t=2.396, P<0.05). The total lymphocyte count and IL-4 of Delta variant group were (1.22±0.86) ×109/L and (0.80±0.23) ng/mL, which were significantly lower than corresponding (1.91±0.70) ×109/L and (1.59±0.59) ng/mL of non-Delta variant group (t=4.329, 9.072, P<0.05), while IL-10 was (7.16±7.77) ng/mL, which was significantly higher than (4.26±3.91) ng/mL of non-Delta mutation group (t=1.980, P<0.05). Subgroup analysis showed that the total lymphocyte count and IL-4 concentration in Delta variant group were (1.04±0.60) ×109/L and (0.74±0.25) ng/ml, which were significantly lower than corresponding (1.62±0.56) ×109/L and (1.56±0.52) ng/mL in non-Delta variant group, in patients with delayed discharge (P<0.05). Conclutions SARS-CoV-2 variant has an impact on clinical manifestations. The patient's B cell count and IL-10 concentration increased or IL-2 and IL-4 concentration decreased within 12 hours of admission indicated variant virus infection. The decrease of total lymphocyte count, especially T lymphocyte reduction, strongly suggests discharge delay due to viral clearance disorder.

Prohibitin and the extracellular matrix are upregulated in murine alveolar epithelial cells with LPS­induced acute injury.

Inflammation of epithelial and endothelial cells accelerates the progress of acute lung injury (ALI), and pulmonary fibrosis is the leading cause of mortality in patients with acute respiratory distress syndrome. Interleukin­6 (IL­6) is a pleiotropic cytokine implicated in the pathogenesis of a number of immune­mediated disorders, and is involved in pulmonary fibrosis. Prohibitin (PHB) is a highly conserved protein implicated in various cellular functions, including proliferation, apoptosis, tumor suppression, transcription and mitochondrial protein folding. PHB was identified to be associated with a variety of pulmonary diseases, including pulmonary fibrosis. Based on the lipopolysaccharide (LPS)­induced cell model of ALI, the present study examined the expression of PHB and the extracellular matrix (ECM) in the process of pulmonary inflammation. MLE­12 cells were divided into 2 groups: The control group was administered sterile PBS; the treatment group was administered 500 ng/ml LPS for 12 h. The mRNA expression of IL­6 in the treatment group was significantly upregulated compared with the control group (P<0.05). The protein expression of IL­6 in the treatment group was markedly increased compared with the control group (P<0.05). ECM components, including collagen­IV and fibronectin, in the treatment group were markedly increased when compared with the control group (P<0.05). The mRNA and protein expression levels of PHB1 and PHB2 were significantly upregulated following treatment with LPS (both P<0.05). The present study identified that PHB and ECM component levels increased in the LPS­induced ALI cell model, and further investigations may be performed to verify the detailed mechanism.

Association of Megsin gene polymorphism with IgA nephropathy risk.

This meta-analysis was conducted to assess the association of Megsin 2093C/T, 2180C/T, C25663G gene polymorphism with the risk of IgA nephropathy (IgAN). The association literatures were identified from PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database) on 1 January 2014, and eligible reports were recruited and synthesized. Seven eligible reports were recruited into this meta-analysis for the association of Megsin 2093C/T, 2180C/T, C25663G gene polymorphism with IgAN risk. In this meta-analysis, the association of Megsin 2093C/T TT genotype with IgAN risk in Asians was found. Interestingly, Megsin C25663G G allele and GG genotype were associated with the risk of IgAN in Asian population. However, Megsin 2180C/T gene polymorphism was not associated with IgAN risk in Asians. In conclusion, Megsin 2093C/T TT genotype, and C25663G G allele and GG genotype were associated with the risk of IgAN in Asian population. However, more studies should be performed in the future to confirm this association.

[The action of active efflux system on multi-drug resistance in methicillin resistant Staphylococcus aureus].

OBJECTIVE: To study the active efflux gene qacB, qacJ and smr in methicillin resistant Staphylococcus aureus (MRSA) and to investigate their effect on the multi-drug resistance (MDR) of MRSA. METHODS: The three pairs of ideal primers of active efflux gene qacB, qacJ and smr were designed by computer with Primer Premier 5.0 software. A total of 124 clinical isolates of MRSA were amplified respectively by polymerase chain reaction (PCR) with above mentioned primers. The PCR products were separated by electrophoresis on an 1.5% agarose gel with 0.5 microg/ml ethidium bromide. Reserpine inhibition test was used to observe the changes of the susceptibility to antibiotics of MRSA which had qacB, qacJ and smr genes separately. RESULTS: Of the 124 strains of MRSA, 86 strains had qacB, 45 strains had qacJ and 32 strains had smr gene. Reserpine inhibition test showed that the minimal inhibitory concentration (MIC) decreased 2 to 32 times for MRSA to levofloxacin and rifampin. CONCLUSION: MRSA have qacB, qacJ and smr active efflux systems, which play a very important role in multiple antibiotic resistance.