AIM: To observe the changes of serum nitric oxide and the production level of IL-1 in different period of coxsackievirus B 4 (CB 4V)-induced insulin-dependent diabetic mice.METHODS: The insulin-dependent diabetes mellitus (IDDM) animal model induced by CB 4V infection was established. Serum nitric oxide level was estimated by nitrate reductase method after infection 72 h,1 week, 3 weeks,6 weeks,8 weeks, respectively. At the same time, level of IL-1 produced by peritoneal M? was measued.RESULTS: (1) Changes of serum nitric oxide: serum nitric oxide level in control group remained normal level. The serum nitric oxide level in diabetic group increased significantly at 72 h after infection(P0.05). (2) IL-1 activities: IL-1 activities were increased obviously from 72 h to 3 weeks after virus infection, but decreased to normal level after 6 weeks.CONCLUSION: Nitric oxide may be one of the important factors in the development of CB 4V-induced IDDM.

Objective To develop a sensitive, specific, rapid and easy method for detecting E. coli O157 : H7 and other Shiga toxin-producing E. coli in food and clinical specimens. Methods A circular probe and capture probe specific for Shiga toxin-2 (stx2) gene had been synthesized and was used for determining the sensitivity of ramification amplification method (RAM). Different serotypes which contained stx2 gene, including an E. coli O157 : H7, an E. coli O46 : H38, an E. coli O111 : NM, an E. coli O22 : H8 and E. coli ATCC23716 (stx2 gene negative) were used for determining the specificity. All strains were detected by RAM to determine whether they contained stx2 gene. Real-time RAM was further studied to detect stx2 gene. Results The lowest number targets detected by RAM assay was 10 copies of stx2, indicating that RAM assay was as sensitive as conventional PCR. The result of specificity showed that different serotypes of strains were all positive for stx2 gene, while nonpathogenic E. coli ATCC23716 was negative. Among 32 isolates, 28 STEC isolates containing stx2 gene were positive by RAM assay, while others were negative. The RAM results were 100% in concordance with that of PCR. The real-time RAM results also showed that as many as 10 bacteria can be detected and the time of appearance of detectable signal was depended on the target concentration. Conclusion RAM assay can offer an alternative method for PCR to detect E. coli O157 : H7 and STEC in all types of specimens because of its simplicity and isothermal amplification.

Objective:To prepare the immunoglobulin Y(IgY) against Avain Influenza Virus (H5N1) and to investgate its inhibitory activity to Influenza virus A (FM1).Methods:Iimmunized by Avain Influenza vaccine,IgY against Avain Influenza Virus was purified from the yolk and then the antibody was enriched by the means:caprylate acid-two-step salt precipitation-gel chromatograph.TD0 of IgY and the inhibory effectiveness were showed by nhibiting cytopathic effect (CPE) thst in MDCK infected with Influenza virus A(FM1).Results:IgY against Avain Influenza Virus was obtained.The TD0 value of IgY against Avain Influenza to MDCK cell line was 1.764 mg/ml,while at the dosage as low as 0.082 8 mg/ml the lnfluenza virus A(FM1) was still inhibited in vitro.Connchusion:Caprylate acid-two-step salt precipitation-gel chromatograph can prepare IgY successfully and the inhibitory effectiveness of IgY is good for inhibition of Influenza virus A(FM1).

ObjectiveTo investigate the role of 15-F2t-isoprostane in intestinal injury induced by intestinal ischemia/reperfusion (I/R) in rats.MethodsThirty-two pathogen free adult male SD rats weighing 230-255 g were randomly divided into 4 groups ( n =8 each):group sham operation (group S) ; group intestinal I/R; group SQ-29548 (TXA2 receptor antagonist) (group SQ) and group DMSO (the solvent).Intestinal I/R was induced by 60 min occlusion of superior mesenteric artery (SMA) followed by 120 main reperfusion in groups I/R,SQ and DMSO SQ-29548 2 μmol/kg and DMSO were injected subcutaneusly at abdominal wall at 30 min before SMS in groups SQ and DMSO respectively.Arterial blood samples were taken at 120 min of reperfusion for determination of serum diamine oxidase (DAO) activity and 15-F2t-isoprostane,endothelin-1 (ET-1) and thromboxane B2 (TXB2) concentrations.Intestinal tissues were removed for microscopic examination and determination of myeloperoxidase (MPO) and SOD activities,MDA and lactate contents.Intestinal damage was assessed and scored according to Chiu (0 =normal,5 =disruption of tunica propria,bleeding and ulceration).ResultsIntestinal I/R significantly increased Chiu's score,MDA and lactate contents and MPO activity and decreased SOD activity in intestine in group I/R as compared with group S.SQ-29548 pretreatment significantly decreased Chiu's score,lactate content and MPO activity in intestine and increased intestinal SOD activity and decreased serum DAO activity and ET-1 concentration in group SQ as compared with group I/R.Conclusion15-F2t-isoprostane is involved in the development of intestinal injury induced by intestinal I/R by activating TXA2 receptor,increasing ET-1 production and promoting neutrophil infiltration.

Objective To analyze the genotype of Japaneso encephalitis virus (JEV) strains isola-ted in 2004 from mosquitoes collected in Bazhong city, Sichuan province of China, and the characters of amino acid in the PrM and E gene. Methods The isolated virus strains from mosquitoes were identified by biological, serological and molecular biology. PrM and E segments of the isolated JEV were amplified by RT-PCR, the PCR products were purified and sequenced. Multiple alignment, phylogenetic and amino acid (AA) analysis were carried out by Clustal X (1.8) , MEGA4 and GENEDOC (3.2) . Results The total of 4688 mosquitoes were collected including Armigeres and Culex. Six isolates were identified be-longing to genotype 1 JEV. The comparison between new genotype 1 JEV strains and live attenuated vaccine strain SA14-14-2 in PrM and E gene showed that total 3 sites amino acid differences in PrM gene and 14 sites in E gene, respectively. Three sites (PrM2, 64 and 65 ) in PrM protein and four sites (E129, 222,327 and 366) in E protein were only belonging to genotype 1 JEV. Conclusion The new isolated JEV strains in Sichuan province belong to genotype 1. It suggests that the vaccine strain SA14-14-2 currently used for preventing Japanese encephalitis is able to protect people against JEV, although in the segments of it had some amino acid differences between vaccine strain and the epidemic genotype 1 JEV strains in PrM and E gene.

Objective: To explore the buffering effect of positive childhood experiences (PCEs) on mental health risks among adolescents before and after COVID-19 epidemic. Methods: In October 2019 (before the outbreak of COVID-19), 1 322 students from grades 4 to 9 were recruited from primary and secondary schools in two counties of Chizhou city, Anhui Province. A questionnaire survey was conducted to collect general demographic information, PCEs, depressive symptoms, anxiety symptoms, self harm behavior, suicidal ideation. Follow up survey was conducted after school re opening (May 2020). Mental health status before and after the COVID-19 epidemic was compared among students with different PCEs by multiple logistic regression analyses. Results: The detection rates of depressive symptoms, anxiety symptoms, self harm behavior and suicidal ideation (22.6%, 16.0%, 40.0%, 29.9%) of the respondents after school re opening were significantly higher compared that before the epidemic (16.5%, 13.5%, 31.1 %, 22.6%). There were no significant differences in the detection rates of depressive symptoms, anxiety symptoms,self harm behavior and suicidal ideation between high PCEs group before and after the epidemic ( Z =-0.05,0.27,0.84,1.84, P >0.05). Multivariate Logistic regression analysis showed that the risk of depressive symptoms and self harm behavior in the low PCEs group after school re opening was 1.39 times higher than that before the epidemic (95% CI= 1.05 -1.84, P <0.05). The risk of non suicidal self injury behavior in the low PCEs group after school re opening was 1.31 times higher than that before the epidemic (95% CI= 1.05 -1.62, P <0.05). There were no significant differences in mental health detection rates in high PCEs group before and after the epidemic ( P >0.05). Conclusion During the time of COVID-19 epidemic, PCEs is associated with lower rates of depressive symptoms, anxiety symptoms, self harm behavior and suicide ideation in adolescents. The findings suggest that more support and help should be given to adolescents from the perspectives of family, school and peers, so as to reduce the adverse effects of public health emergencies on adolescents mental health.

Objective To explore the predictive value of cognitive function trend after ACI for the recurrence risk of cerebral infarction.Methods A total of 256 ACI patients admitted to our hospi-tal from January 2021 to December 2023 were enrolled retrospectively.Based on their MoCA score at 3 months after onset,they were assigned into 96 cases of no PSCI,51 cases of improved PSCI,17 cases of delayed PSCI and 92 cases of persistent PSCI.According to the results of MoCA at 2 weeks after onset,they were divided into 133 cases of PSCI group and 123 cases of non-PSCI group.The clinical data of the ACI patients were compared between the two groups,and their cog-nitive function trends were analyzed.Results Advanced age,and larger proportions of female,du-al antiplatelet therapy and PSQI＞5 were observed in the PSCI group than the non-PSCI group(P＜0.05,P＜0.01).There were significant differences in the incidences of recurrence and poor prognosis in the ACI patients with different cognitive function trends(P＜0.01).The persistent PSCI was associated with the increased risk of recurrence of cerebral infarction and poor prognosis(P＜0.05).The AUC value of persistent PSCI in predicting the recurrence and poor prognosis of cerebral infarction was 0.703(95％CI:0.631-0.767)and 0.595(95％CI:0.521-0.666),respec-tively.Conclusion Persistent PSCI can be used as a predictor of recurrence of cerebral infarction,and it also increases the risk of cognitive dysfunction in ACI patients.