Objective To investigate the effect of estrogen on regression of vascular calcification in rats induced by vitamin D3 plus nicotine.Methods Ninety-six female SD rats were divided randomly into control group (n=24) and calcification group (n=72).Vascular calcification of 72 rats was induced by vitamin D3 and nicotine (VDN).On the day 1,the VDN group rats were injected with vitamin D3(300 000 U/kg,i.m),and were intragastric administrated with nicotine (25 mg/kg),after 9 hours,another dosage of nicotine was given again.After 4 weeks,the VDN group rats were subdivided randomly into 4 groups:VDN group(n=16),Sham operation group (n=16),ovariotomy group (n=16),estrogen group(after ovariotomy,17β-estrogen was subcutaneously injected,50 μg· kg-1· d-1,n=16).Results After 4 weeks,the VDN group showed obvious vascular calcification,and calcium content of the vessel wall was significantly higher than that of control group (P＜0.01).Extensive calcification was witnessed on the aortic tunica media of the VDN group.After 12 and 8 weeks,the calcium content of the vessel wall in each subdivided groups was significantly lower than that at 4 weeks point(P＜0.01),and the lowest calcinm content was in estrogen group,meanwhile the reduction of previously accumulated arterial calcium precipitate in each group was different.Conclusions It is a reversible process that vascular calcification induced by vitamin D plus nicotine in rats.Estrogen can promote the regression of vascular calcification.

Objective To determine the differentially expressed genes in the development of vascular medium calcification in rats using the suppression subtractive hybridization (SSH). Methods Twenty-four 6-week old SD rats of specific pathogen free grade were recruited and randomly allocated into calcified group (n=12) and control group (n=12). Rats were made for vascular calcification model in calcified group (vitamin D3 plus nicotine, VDN). All rats were sacrificed to measure concentration of calcium in the arterial tissue and examine the pathological lesion changes. RNA in rat aortic tunica tissue was extracted and reverse transcripted into cDNA. cDNA fragments which highly expressed calcification were isolated in calcified group using the SSH. Differentially expressed genes with cDNA fragment were inserted into PMD18-T plasmid vector and transformed to competent DH-5α by means of heating transfer. cDNA libraries of differentially expressed gene between calcified group and control group were successfully constructed. Recombinant vectors were analyzed by colony PCR. Positive genes were randomly selected for sequencing and analyzed by BLAST. Six genes, for example, were randomly selected for RT-PCR certification. Results (1) The pathological examination results demonstrated that in calcified group there were obvious calcium diposits and media squirm in tunica media of rat aortic wall, while in control group no calcium diposit was found. (2) There was statistical significance in calcium concentration in vascular tissue between calcified group[(15.34 ± 2.51)mg/g] and control group [(5.20 ± 0.75) mg/g] (P＜0.01). (3) Subtracted libraries in vascular calcification was successfully established. Ninety-two positive clones in positive library and 18 positive clones in reverse library were obtained after the colony PCR identification. The length of insertion fragments was concentrated between 150 bp and 400 bp. Calcification-related 43 up-regulated genes and 11 down-regulated genes were obtained through sequencing and BLAST analysis in positive clones. RT-PCR validation indicated that the expressions of 5 genes such as CytoP450 and Nell1 had greater increase in calcified group than those in control group, the average fold change was 1.71.Conclusions Model of vascular calcification induced by vitamin D3 plus nicotine is successfully constructed. Related gene expression spectrum is changed in the process of vascular calcification.Some ossification genes and genes associated with apoptosis, oxidation, inflammation and cytokines are up-regulated. At the same time, some genes which possibly inhibit vascular calcification are down -regulated.

Objective To investigate the characteristics of pathogenic bacteria in cancer patients with severe infection after radiotherapy and chemotherapy and the application value of metagenomic next-generation sequencing(NGS)in the detection of pathogenic bacteria.Methods A total of 112 patients with severe infection after malignant tumor radiation and chemotherapy admitted to Department of Critical Care Medicine of Wuwei Tumor Hospital from October 2019 to August 2023 were selected as the research objects.A total of 150 specimens from suspected infection sites were collected and tested by traditional etiology and NGS.The characteristics of pathogenic bacteria in severe infection of cancer patients after chemoradiotherapy and the application value of NGS in pathogen detection were analyzed.Results Among 150 samples of 112 patients with severe infection after radiotherapy and chemotherapy,the highest proportion of respiratory system infection was 51.79%(58 cases),followed by 25.89%(29 cases)of bloodstream infection,the lowest central nervous system infection rate was 1.79%(2 cases).Gram-negative bacteria were the most common pathogenic bacteria[NGS 35.33%(53 cases),traditional pathogen detection 23.33%(35 cases)],followed by Gram-positive bacteria[NGS 20.67%(31 cases),traditional pathogen detection 12.00%(18 cases)],and multi-drug resistant bacteria infection rate was more than 80.00%,multi-drug resistant fungal infection rate also reached 28.57%.In the patients with severe infection after radiotherapy and chemotherapy,the positive rate of pathogenic bacteria of NGS was significantly higher than that of traditional pathogen detection[87.33%(131/150)vs.42.67%(64/150),P＜0.01],and the positive detection rate of Gram-negative bacteria,Gram-positive bacteria,fungi and other pathogens was significantly higher than that of traditional pathogen detection[Gram-negative bacteria:35.33%(53/150)vs.23.33%(35/150),Gram-positive bacteria:20.67%(31/150)vs.12.00%(18/150),fungi:22.67%(34/150)vs.6.67%(10/150),others:8.67%(13/150)vs.0.67%(1/150),both P＜0.05].Conclusions The detection rate of pathogenic bacteria of NGS in patients with severe infection after radiotherapy and chemotherapy was significantly higher than that of traditional pathogen detection.The distribution and drug resistance of pathogenic bacteria in severe infection after radiotherapy and chemotherapy are unique,and strengthening the detection of pathogenic bacteria is helpful to improve the curative effect.

Objective To investigate the expression of m6 A methyltransferase-like protein 14(METTL14)in the hippocampus of depression-like mice,and to provide a theoretical basis for further study of the molecular mecha-nism of depression and new drug targets.Methods 1)Twenty-four male C57BL/6J mice were divided into con-trol group and depression model group.The control group was fed normally,and the model group was kept in single animal cage for 4 months and added with Chronic Unpredictable Animal Stress(CUMS)to establish the depression-like model.2)After modeling,depression-like behaviors in model group were tested using forced swimming test(FST),sucrose preference test(SPT)and tail suspension test(TST).3)Twenty-four hours after completion of behavioral test,the hippocampus tissues of mice were collected,and the expression of m6 A methyltransferase-like protein METTL14 in the hippocampus of mice was detected by molecular biology experiments.Results 1)The mice in the model group showed significant depression-like behavior;2)The expression of MET-TL14 in the hippocampus of the model group showed an increased mRNA expression with the increased m6 A modifi-cation.3)In the model group,the expression of METTL14 in hippocampal CA1,CA3 and DG districts increased and there was neuronal damage found.Conclusions m6 A methylation function has been proved to be more active in the hippocampus of depressed mice.