Pathological Changes and Cause of Death Associated with the Global Novel Coronavirus Disease (COVID-19).

The coronavirus disease 2019 (COVID-19) has been a global epidemic for more than three years, causing more than 6.9 million deaths. COVID-19 has the clinical characteristics of strong infectivity and long incubation period, and can cause multi-system damage, mainly lung damage, clinical symptoms of acute respiratory distress syndrome (ARDS) and systemic multiple organ damage. The SARS-CoV-2 virus is still constantly mutating. At present, there is no global consensus on the pathological changes of COVID-19 associated deaths and even no consensus on the criteria for determining the cause of death. The investigation of the basic pathological changes and progression of the disease is helpful to guide the clinical treatment and the development of therapeutic drugs. This paper reviews the autopsy reports and related literature published worldwide from February 2020 to June 2023, with a clear number of autopsy cases and corresponding pathological changes of vital organs as the inclusion criteria. A total of 1 111 autopsy cases from 65 papers in 18 countries are included. Pathological manifestations and causes of death are classified and statistically analyzed, common pathological changes of COVID-19 are summarized, and analytical conclusions are drawn, suggesting that COVID-19 infection can cause life-threatening pathological changes in vital organs. On the basis of different health levels of infected groups, the direct cause of death is mainly severe lung damage and secondary systemic multiple organ failure.

Construction of a Stable Expression Cell Line of Human Phospholamban. / 人源性受磷蛋白稳定表达细胞系的构建.

OBJECTIVES: To construct a cell line that can stably express human phospholamban(PLN) and initially explore its application in the study of myocardial toxicity mechanism. METHODS: FastCloning method was used to insert the open reading frame sequence of target gene PLN into eukaryotic expression vector pcDNA5/FRT/TO(hereinafter referred to as pDFT) to construct the pDFT-PLN-Flag plasmid. The Flp-InTM T-RExTM 293 cells were generated by cotransfection of the constructed plasmid and pOG44 plasmid to express the target gene. Successfully recombined monoclonal cell lines were screened by hygromycin B resistance. Western blot and indirect immunofluorescence (IFA) were used to examine the expression of the target protein in recombinant cells. After the cell line was exposed to aconitine, it was verified by Western blot to detect changes in PLN protein phosphorylation. RESULTS: After PCR amplification of the recombinant plasmid and DNA electrophoresis, the length of the amplified product is the same as the known PLN gene fragment, which is consistent with the open reading frame (ORF) sequence of the human PLN gene after sequencing. IFA and Western blot showed that the constructed proliferation cell line can stably express high levels of human PLN under induction and regulation. Preliminary results showed that the phosphorylation level of Thr17-PLN decreased after two hours of exposure to 1 µmol/L aconitine. CONCLUSIONS: This human cell line can stably express PLN and can be used to study the mechanism of action of aconitine on the cell at molecular level.

Erchen Decoction Ameliorates the Metabolic Abnormalities of High-Fat Diet-Fed Rats.

Objective: Brown adipose tissue (BAT) dissipates chemical energy to protect against obesity. In the present study, we aimed to determine the effects of Erchen decoction on the lipolysis and thermogenesis function of BAT in high-fat diet-fed rats. Methods: Sprague-Dawley rats were randomly divided into four groups, which were fed a control diet (C) or a high-fat diet (HF), and the latter was administered with high and low doses of Erchen decoction by gavage once a day, for 12 weeks. Body weight, the serum lipid profile, serum glucose, and insulin levels of the rats were evaluated. In addition, the phosphorylation and protein and mRNA expression of AMP-activated protein kinase (AMPK), adipose triglyceride lipase (ATGL), peroxisome proliferator-activated receptor γ coactivator- (PGC-) 1α, and uncoupling protein 1 (UCP-1) in BAT were measured by immunoblotting and RT-PCR. Results: Erchen decoction administration decreased body weight gain and ameliorated the abnormal lipid profile and insulin resistance index of the high-fat diet-fed rats. In addition, the expression of p-AMPK and ATGL in the BAT was significantly increased by Erchen decoction. Erchen decoction also increased the protein and mRNA expression of PGC-1α and UCP-1 in BAT. Conclusion: Erchen decoction ameliorates the metabolic abnormalities of high-fat diet-fed rats, at least in part via activation of lipolysis and thermogenesis in BAT.

[Effects of organic fertilizer application on crop yield and soil properties in rice-wheat rotation system: A meta-analysis]. / 稻麦轮作体系下有机肥施用对作物产量和土壤性质影响的整合分析.

To clarify the effects of organic fertilizer application on crop yield and soil properties in rice-wheat rotation system in China, we carried out a meta-analysis to quantitatively evaluate the effects of organic fertilizer types (ordinary organic fertilizer, biochar, and straw), fertilization regimes (organic fertilizer alone, organic fertilizer + partial chemical fertilizer, and organic fertilizer + full amount of chemical fertilizer), and experiment duration (short term, medium term, and long term) on soil properties and the yield of rice and wheat, as well as their responses to soil conditions (acid, neutral, basic). Results showed that the application of organic fertilizer had similar yield-increase effect on rice yield (3.1%) and wheat yield (3.0%) compared to chemical fertilizer application alone. The effect of organic fertilizer application on soil quality was more obvious, significantly reducing soil bulk density by 5.7%, and increasing the concentrations of soil organic matter, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, microbial biomass carbon, and microbial biomass nitrogen by 11.7%-38.4%. Among different types of organic fertilizer, the effects of ordinary organic fertilizer and biochar on soil properties improvement were better than straw. Compared to the organic fertilizer application alone, the effects of organic fertilizer combined with chemical fertilizer on crop yield was better, but poorer on soil property improvement. With the increasing duration of organic fertilizer application, crop yield and soil fertility gradually increased. Under the condition of acid soil, the effect of organic fertilizer application on crop yield was the best. The annual yield of rice and wheat showed significant negative correlation with soil bulk density, but a significant positive correlation with the concentrations of soil total nitrogen, available phosphorus, available potassium, and microbial biomass nitrogen.

The ß3 Adrenergic Receptor Agonist CL316243 Ameliorates the Metabolic Abnormalities of High-Fat Diet-Fed Rats by Activating AMPK/PGC-1α Signaling in Skeletal Muscle.

PURPOSE: Skeletal muscle has a major influence on whole-body metabolic homeostasis. In the present study, we aimed to determine the metabolic effects of the ß3 adrenergic receptor agonist CL316243 (CL) in the skeletal muscle of high-fat diet-fed rats. METHODS: Sprague-Dawley rats were randomly allocated to three groups, which were fed a control diet (C) or a high-fat diet (HF), and half of the latter were administered 1 mg/kg CL by gavage once weekly (HF+CL), for 12 weeks. At the end of this period, the serum lipid profile and glucose tolerance of the rats were evaluated. In addition, the phosphorylation and protein and mRNA expression of AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ coactivator (PGC)-1α, and carnitine palmitoyl transferase (CPT)-1b in skeletal muscle were measured by Western blot analysis and qPCR. The direct effects of CL on the phosphorylation (p-) and expression of AMPK, PGC-1α, and CPT-1b were also evaluated by Western blotting and immunofluorescence in L6 myotubes. RESULTS: CL administration ameliorated the abnormal lipid profile and glucose tolerance of the high-fat diet-fed rats. In addition, the expression of p-AMPK, PGC-1α, and CPT-1b in the soleus muscle was significantly increased by CL. CL (1 µM) also increased the protein expression of p-AMPK, PGC-1α, and CPT-1b in L6 myotubes. However, the effect of CL on PGC-1α protein expression was blocked by the AMPK antagonist compound C, which suggests that CL increases PGC-1α protein expression via AMPK. CONCLUSION: Activation of the ß3 adrenergic receptor in skeletal muscle ameliorates the metabolic abnormalities of high-fat diet-fed rats, at least in part via activation of the AMPK/PGC-1α pathway.