ObjectiveTo investigate the effect of dapagliflozin on liver lipid metabolism and gut microecology in mice with metabolic associated fatty liver disease （MAFLD）， and to clarify its potential mechanism. MethodsA total of 50 male C57 mice were randomly divided into Control group， type 2 diabetes+MAFLD group （MAFLD group）， dapagliflozin group （DAPA group）， meldonium group （THP group）， and dapagliflozin+meldonium group （DAPA+THP group）， with 10 mice in each group. High-fat diet combined with streptozotocin was used to establish a mouse model of MAFLD. Treatment outcomes were assessed based on histopathology and biochemical parameters such as blood glucose and blood lipid levels， and the transcriptomic and metagenomic analyses were used to identify differentially expressed genes and the changes in gut microbiota. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups， and the least significant difference t-test was used for comparison between two groups； the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups， and the Nemenyi test was used for comparison between two groups. ResultsHistopathological examination showed that the mice in the MAFLD group had excessive lipid deposition and hepatocyte steatosis； compared with the MAFLD group， the DAPA group had a significant improvement in hepatocyte steatosis， while the THP group and the DAPA+THP group had a less significant improvement compared with the DAPA group. Compared with the Control group， the MAFLD group had a significant increase in fasting blood glucose （P<0.05）， significant increases in the serum levels of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， malondialdehyde， total cholesterol， triglyceride， and low-density lipoprotein cholesterol （P<0.05）， and a significant reduction in high-density lipoprotein cholesterol （P<0.05）. Compared with the MAFLD group， the DAPA group， the THP group， and the DAPA+THP group had significant reductions in the serum levels of ALT and AST （P<0.05）. The results of 16S rRNA sequencing showed that compared with the Control group， the MAFLD group had significant changes in gut microbiota， with an increase in Firmicutes and a reduction in Bacteroidetes， as well as reductions in S24-7 and Erysipelotrichaceae and an increase in Lactobacillaceae. The levels of the above flora were upregulated to normal levels in the DAPA group， the THP group， and the DAPA+THP group. The liver transcriptomic analysis showed that the enriched metabolic pathways included steroid hormone biosynthesis， bile secretion， inflammatory mediator regulation of TRP， fatty acid elongation， and lipid biodegradation processes， and the related genes mainly involved the key targets of lipid metabolism such as Acot2， Angptl4， Scd2， and Npc1l1. ConclusionDapagliflozin can alleviate MAFLD through the pathways such as steroid hormone biosynthesis， bile secretion， inflammatory mediator regulation of TRP， and fatty acid elongation， as well as by regulating gut microbiota homeostasis.

BACKGROUND:The liver,as the main target organ for arsenic toxicity,has become the focus of studies related to the mechanism of action of arsenic toxicity.OBJECTIVE:To investigate the effects of sodium arsenite(NaAsO2)on lipid metabolism,cell proliferation,apoptosis,and expression of related regulatory factors in human normal hepatocytes.METHODS:MIHA normal human hepatocyte cell lines were exposed to 0,10,20,and 30 μmol/L NaAsO2 for 48 hours.Cell morphology changes were observed by light microscopy.Cell viability was detected by CCK-8 assay.The cell serum total cholesterol,triacylglycerol,and total bile acids were detected by single-agent COD-PAP assay,single-agent GPO-PAP assay,and enzyme microplate assay.The intracellular lipid content was detected by oil red O staining.Cell proliferation was detected by Edu-488 infiltration.Cell cycle and apoptosis were detected by PI staining and Annexin V-FITC/PI dual-labeling combined with flow cytometry.The mRNA and protein expression levels of hepatocyte nuclear factor 4 alpha,cholesterol 7α-hydroxylase,and farnesoid X receptor were detected by real-time fluorescence quantitative PCR and western blot assay,respectively.RESULTS AND CONCLUSION:(1)Compared with the control group(0 μmol/L NaAsO2),with the increase of NaAsO2 concentration:MIHA cell viability decreased gradually.The content of total cholesterol and triacylglycerol in cell supernatant increased gradually,while the contents of total bile acids decreased gradually.The content of intracellular lipid increased gradually.The proportion of cells stagnating in S phase and G2/M phase gradually increased,and the apoptosis rate gradually increased.The expression level of hepatocyte nuclear factor 4 alpha mRNA did not show significant changes,while cholesterol 7α-hydroxylase and farnesoid X receptor mRNA expression levels decreased.The protein expression levels of hepatocyte nuclear factor 4 alpha,cholesterol 7α-hydroxylase,and farnesoid X receptor decreased gradually.(2)NaAsO2 has cytotoxicity,significantly reduces MIHA cell viability,induces cell steatosis,inhibits cell proliferation,and induces cell apoptosis.NaAsO2 down-regulates hepatocyte nuclear factor 4 alpha protein expression and the transcription and expression of cholesterol 7α-hydroxylase and farnesoid X receptor,which further induces lipid metabolism disorders in hepatocytes.

Objective To investigate the effect and potential mechanism of rat mesenchymal stem cells(MSC)on D-galactose-induced brain-tissue aging.Methods A rat brain-aging model was established by injecting D-galactose,and rats in the treatment group received MSC injections via the tail vein.Superoxide dismutase(SOD)activity and malondialdehyde(MDA)levels were assessed in rat brain tissue at the end of the experiment,and pathological changes in brain tissue were observed by hematoxylin-eosin(HE)staining.Expression levels of the inflammatory factors interleukin(IL)-1 and IL-6,the pathway proteins brain-derived neurotrophic factor(BDNF)-tropomyosin receptor kinase B(TrkB),the negative growth regulators p53 and p16,as well as vascular endothelial growth factor(VEGF)and basic fibroblast growth factor(bFGF)were observed by polymerase chain reaction(PCR)and Western Blot.Results Brain levels of SOD activity were significantly increased and MDA levels were significantly decreased in rats in the modle group compared with the treatment group(P＜0.05).The pathological state of the cerebral cortex and hippocampus were improved and the number of neurons and nucleus pulposus ratio in the brain were increased in the treatment group,as shown by HE staining.Expression levels of IL-1,IL-6,p53,and p16 were significantly decreased,while BDNF,TrkB,VEGF,and bFGF were significantly increased in the treatment group compared with the model group,as shown by PCR and Western Blot(P＜0.05).Conclusions These result suggest that MSCs potentially mitigate D-galactose-induced cerebral senescence by concurrently modulating the BDNF-TrkB axis to attenuate oxidative/inflammatory damage,while enhancing the secretion of vasculotrophic(VEGF)and neurotrophic(bFGF)factors for neuronal maintenance.

Objective To investigate the effect and potential mechanism of rat mesenchymal stem cells(MSC)on D-galactose-induced brain-tissue aging.Methods A rat brain-aging model was established by injecting D-galactose,and rats in the treatment group received MSC injections via the tail vein.Superoxide dismutase(SOD)activity and malondialdehyde(MDA)levels were assessed in rat brain tissue at the end of the experiment,and pathological changes in brain tissue were observed by hematoxylin-eosin(HE)staining.Expression levels of the inflammatory factors interleukin(IL)-1 and IL-6,the pathway proteins brain-derived neurotrophic factor(BDNF)-tropomyosin receptor kinase B(TrkB),the negative growth regulators p53 and p16,as well as vascular endothelial growth factor(VEGF)and basic fibroblast growth factor(bFGF)were observed by polymerase chain reaction(PCR)and Western Blot.Results Brain levels of SOD activity were significantly increased and MDA levels were significantly decreased in rats in the modle group compared with the treatment group(P＜0.05).The pathological state of the cerebral cortex and hippocampus were improved and the number of neurons and nucleus pulposus ratio in the brain were increased in the treatment group,as shown by HE staining.Expression levels of IL-1,IL-6,p53,and p16 were significantly decreased,while BDNF,TrkB,VEGF,and bFGF were significantly increased in the treatment group compared with the model group,as shown by PCR and Western Blot(P＜0.05).Conclusions These result suggest that MSCs potentially mitigate D-galactose-induced cerebral senescence by concurrently modulating the BDNF-TrkB axis to attenuate oxidative/inflammatory damage,while enhancing the secretion of vasculotrophic(VEGF)and neurotrophic(bFGF)factors for neuronal maintenance.

BACKGROUND:The liver,as the main target organ for arsenic toxicity,has become the focus of studies related to the mechanism of action of arsenic toxicity.OBJECTIVE:To investigate the effects of sodium arsenite(NaAsO2)on lipid metabolism,cell proliferation,apoptosis,and expression of related regulatory factors in human normal hepatocytes.METHODS:MIHA normal human hepatocyte cell lines were exposed to 0,10,20,and 30 μmol/L NaAsO2 for 48 hours.Cell morphology changes were observed by light microscopy.Cell viability was detected by CCK-8 assay.The cell serum total cholesterol,triacylglycerol,and total bile acids were detected by single-agent COD-PAP assay,single-agent GPO-PAP assay,and enzyme microplate assay.The intracellular lipid content was detected by oil red O staining.Cell proliferation was detected by Edu-488 infiltration.Cell cycle and apoptosis were detected by PI staining and Annexin V-FITC/PI dual-labeling combined with flow cytometry.The mRNA and protein expression levels of hepatocyte nuclear factor 4 alpha,cholesterol 7α-hydroxylase,and farnesoid X receptor were detected by real-time fluorescence quantitative PCR and western blot assay,respectively.RESULTS AND CONCLUSION:(1)Compared with the control group(0 μmol/L NaAsO2),with the increase of NaAsO2 concentration:MIHA cell viability decreased gradually.The content of total cholesterol and triacylglycerol in cell supernatant increased gradually,while the contents of total bile acids decreased gradually.The content of intracellular lipid increased gradually.The proportion of cells stagnating in S phase and G2/M phase gradually increased,and the apoptosis rate gradually increased.The expression level of hepatocyte nuclear factor 4 alpha mRNA did not show significant changes,while cholesterol 7α-hydroxylase and farnesoid X receptor mRNA expression levels decreased.The protein expression levels of hepatocyte nuclear factor 4 alpha,cholesterol 7α-hydroxylase,and farnesoid X receptor decreased gradually.(2)NaAsO2 has cytotoxicity,significantly reduces MIHA cell viability,induces cell steatosis,inhibits cell proliferation,and induces cell apoptosis.NaAsO2 down-regulates hepatocyte nuclear factor 4 alpha protein expression and the transcription and expression of cholesterol 7α-hydroxylase and farnesoid X receptor,which further induces lipid metabolism disorders in hepatocytes.

BACKGROUND: T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), an inhibitory receptor expressed on T cells, plays a dysfunctional role in antiviral infection and antitumor activity. However, it is unknown whether TIGIT expression on T cells influences the immunological effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccines. METHODS: Forty-five people living with HIV (PLWH) on antiretroviral therapy (ART) for more than two years and 31 healthy controls (HCs), all received a third dose of a SARS-CoV-2 inactivated vaccine, were enrolled in this study. The amounts, activation, proportion of cell subsets, and magnitude of the SARS-CoV-2-specific immune response of TIGIT + CD4 + and TIGIT + CD8 + T cells were investigated before the third dose but 6 months after the second vaccine dose (0W), 4 weeks (4W) and 12 weeks (12W) after the third dose. RESULTS: Compared to that in HCs, the frequency of TIGIT + CD8 + T cells in the peripheral blood of PLWH increased at 12W after the third dose of the inactivated vaccine, and the immune activation of TIGIT + CD8 + T cells also increased. A decrease in the ratio of both T naïve (T N ) and central memory (T CM ) cells among TIGIT + CD8 + T cells and an increase in the ratio of the effector memory (T EM ) subpopulation were observed at 12W in PLWH. Interestingly, particularly at 12W, a higher proportion of TIGIT + CD8 + T cells expressing CD137 and CD69 simultaneously was observed in HCs than in PLWH based on the activation-induced marker assay. Compared with 0W, SARS-CoV-2-specific TIGIT + CD8 + T-cell responses in PLWH were not enhanced at 12W but were enhanced in HCs. Additionally, at all time points, the SARS-CoV-2-specific responses of TIGIT + CD8 + T cells in PLWH were significantly weaker than those of TIGIT - CD8 + T cells. However, in HCs, the difference in the SARS-CoV-2-specific responses induced between TIGIT + CD8 + T cells and TIGIT - CD8 + T cells was insignificant at 4W and 12W, except at 0W. CONCLUSIONS TIGIT expression on CD8 + T cells may hinder the T-cell immune response to a booster dose of an inactivated SARS-CoV-2 vaccine, suggesting weakened resistance to SARS-CoV-2 infection, especially in PLWH. Furthermore, TIGIT may be used as a potential target to increase the production of SARS-CoV-2-specific CD8 + T cells, thereby enhancing the effectiveness of vaccination.
Humans ; Antibodies, Viral ; CD8-Positive T-Lymphocytes ; COVID-19/complications* ; COVID-19 Vaccines/immunology* ; HIV Infections/complications* ; Receptors, Immunologic ; SARS-CoV-2

This study deeply analyzes the common problems of three military medical universities in the management of undergraduate extracurricular scientific research, such as lack of communication means, limited online resources, backward laboratory opening and low utilization rate of equipment. We have built a cloud platform management system for undergraduate extracurricular scientific research. This system firstly sets up a teaching resources storage module including videos, PPTs, documents, pictures, electronic materials, question bank, etc. Then four subsystems for different roles of students, mentors, experimental teaching staff and administrators are constructed. Finally, this system realizes independent experiments by students, real-time evaluation by mentors, instrument sharing and efficient management through the seamless connection with the user terminal equipment. And the study also makes evaluation on the present usage.

Objective: To explore the importance of the diagnosis and treatment value of laparoscopy and hysteroscopy in patients with unexplained infertility. Methods: A total of 519 cases diagnosed as unexplained infertility, received laparoscopy and hysteroscopy in Peking Union Medical College Hospital from May 2012 to December 2015. The causes of infertility were evaluated, and the subjects were followed up to observe the nature pregnancy rate. Results: Among 519 unexplained infertility patients, pelvic abnormalities had been explored in 466 (89.8%, 466/519) cases. Pelvic endometriosis combined with adhesions, pelvic adhesion alone, uterine leiomyoma and uterine cavity polyp were 72.4% (376/519), 12.3% (64/519), 3.7% (19/519) and 1.3% (7/519) respectively. The total natural pregnancy rate within the 3 years of follow up was 53.9% (208/386), and the natural pregnancy rate was 29.8% (31/104) in patients aged 35 years and over. Conclusions The patients with clinical diagnosis of unexplained infertility should be examined by hysteroscopy and laparoscopy. Under the examination, the causes of infertility could be found more intuitively, and targeted treatment could be carried out to improve the pregnancy rate. The natural pregnancy rate of the elderly patients decrease obviously after operation, and the time of natural trying pregnancy should not be too long.

Antiseptic drugs are the most popular anti-infectious drugs in daily use in hospitals, making significant contribution to public health. In view of the increasingly serious problems in the use and management of antiseptic drugs, the Chinese government has taken a series of measures to guide their rational use. However, due to the imperfect regulatory mechanism and weak sense of rational drug use, the problem of irrational use of antiseptic drugs is still existing. By studying the current situation and existing problems of antiseptic drugs in the country, this paper discussed the effective management means of such drugs, and provided feasible strategies and suggestions for standardizing their rational use.

Objective: To investigate the clinical phenotypes and the mutant allele proportion of parents with SCN1A gene mutation mosaicism of Dravet syndrome (DS) children, thus to provide guidance for family reproduction and prenatal diagnosis. Method: The clinical data and peripheral blood DNA samples of DS patients with a SCN1A gene mutation proved by Sanger sequencing were collected prospectively from February 2005 to November 2016 in Department of Pediatrics, Peking University First Hospital. The same mutation was searched in parents and other available relatives. Parental somatic mosaicism was confirmed and quantified by Ion Torrent Personal Genome Machine (PGM) and Raindrop droplet digital PCR (ddPCR). The families were followed up and prenatal diagnosis was provided. Result: Mosaicisms of SCN1A gene mutation in parents were identified in 5.2% (30 out of 575) DS families. Seventeen were fathers and thirteen were mothers. The mutant allele proportion ranged from 1.7% to 32.9% by PGM and from 0.82% to 34.51% by ddPCR, respectively. In 30 parents with somatic mosaicism, thirteen were asymptomatic, ten had a history of febrile seizures (FS), five with epilepsy, one with febrile seizure plus and one had a history of afebrile seizure. Four families had two children with DS. Three siblings of the probands were confirmed genetically with the same pathogenic mutation. One deceased sister of the proband was assumed to have the same pathogenic mutation because she matched DS diagnosis after medical history review despite no blood sample. Two families received prenatal diagnosis. One second pregnancy was terminated because the fetus inherited the mutation as the mother's wish. Conclusion Sanger sequencing detects parents of some children with DS are SCN1A mutation mosaics. PGM and ddPCR can be used for accurate quantification of mutant mosaics, which can provide accurate guidance for family genetic counseling.