Analysis of epidemic characteristics and related factors of norovirus in diarrhea patients in Guangxi, 2015-2020 / 中国热带医学

@#Abstract: Objective　To analyze the epidemiological characteristics and related factors of norovirus in Guangxi from 2015 to 2020, and to provide scientific recommendations for norovirus prevention and control. Methods The foodborne diseases surveillance data were collected from 11 sentinel hospitals through the National Foodborne Disease Monitoring and Reporting System from 2015 to 2020. R software with version 4.0.3 was used for descriptive and statistical analysis, including epidemic curve, chi-square test, and trend chi-square and so on. Logistic regression was used to analyze norovirus-related factors, OR values and 95% confidence intervals were calculated respectively with the statistical test level of P<0.05. Results There were 1 008 norovirus cases detected, with a detection rate of 12.75% (1 008/7 903). Children with age less than 5 years (OR=1.43, 95%CI: 1.13-1.82) and patients at age 20-45 (OR=1.45, 95%CI: 1.13-1.87) were high risk population. The detection rate was higher in autumn (OR=1.29, 95%CI: 1.08-1.53) but lower in summer (OR=0.67, 95%CI: 0.55-0.80). In addition, the tourist area (Guilin City) presented a higher detection rate than other areas (OR=1.41, 95%CI: 1.10-1.80). Aquatic products (OR=1.40, 95%CI: 1.03-1.91), meat and dairy products (OR=1.31, 95%CI: 1.06-1.61) were high-risk foods for norovirus infection. The prevention and control policies of COVID-19 can reduce the possibility of norovirus by 61% (OR=0.39, 95%CI: 0.31-0.49) showed a declining trend (Trend χ2=85.33, P<0.001). In addition, prolonged visit time can lead to 19%-23% decrease in the detection rate of norovirus (OR24-48 hours=0.81, 95%CI: 0.70-0.95; OR>48 hours=0.77, 95%CI: 0.63-0.93). Conclusions　The epidemic of norovirus presented seasonal and regional distribution in Guangxi with a declining detection rate trend in diarrhea patients during recent 6 years. Young children were high-risk population in infection norovirus. The intake of seafood can increase the risk of norovirus infection. The prevention and control policies of COVID-19 can sharply decrease the possibility of infection norovirus. The monitoring of key foods such as seafood should be strengthened, and the early screening of suspected cases should be taken. The norovirus monitoring should be improved to ensure the health of the population.

Isolation and absolute configurations of diastereomers of 8α-hydroxy-T-muurolol and (1α,6ß,7ß)-cadinane-4-en-8α,10α-diol from Chimonanthus salicifolius.

Phytochemical investigation of the aerial parts of Chimonanthus salicifolius resulted in the isolation of two sesquiterpenoids, 8α-hydroxy-T-muurolol and (1α,6ß,7ß)-cadinane-4-en-8α,10α-diol, together with 13 known compounds. The 15 structures were established by means of 1D and 2D NMR spectroscopy. The relative and absolute configurations of 8α-hydroxy-T-muurolol and 8α,11-elemodiol were achieved by NOESY experiments and X-ray crystallography using CuKα radiation. 8α-hydroxy-T-muurolol and (1α,6ß,7ß)-cadinane-4-en-8α,10α-diol showed immunosuppressive activities in a dose-dependent manner.

Structure-guided modification of Rhizomucor miehei lipase for production of structured lipids.

To improve the performance of yeast surface-displayed Rhizomucor miehei lipase (RML) in the production of human milk fat substitute (HMFS), we mutated amino acids in the lipase substrate-binding pocket based on protein hydrophobicity, to improve esterification activity. Five mutants: Asn87Ile, Asn87Ile/Asp91Val, His108Leu/Lys109Ile, Asp256Ile/His257Leu, and His108Leu/Lys109Ile/Asp256Ile/His257Leu were obtained and their hydrolytic and esterification activities were assayed. Using Discovery Studio 3.1 to build models and calculate the binding energy between lipase and substrates, compared to wild-type, the mutant Asp256Ile/His257Leu was found to have significantly lower energy when oleic acid (3.97 KJ/mol decrease) and tripalmitin (7.55 KJ/mol decrease) were substrates. This result was in accordance with the esterification activity of Asp256Ile/His257Leu (2.37-fold of wild-type). The four mutants were also evaluated for the production of HMFS in organic solvent and in a solvent-free system. Asp256Ile/His257Leu had an oleic acid incorporation of 28.27% for catalyzing tripalmitin and oleic acid, and 53.18% for the reaction of palm oil with oleic acid. The efficiency of Asp256Ile/His257Leu was 1.82-fold and 1.65-fold that of the wild-type enzyme for the two reactions. The oleic acid incorporation of Asp256Ile/His257Leu was similar to commercial Lipozyme RM IM for palm oil acidolysis with oleic acid. Yeast surface-displayed RML mutant Asp256Ile/His257Leu is a potential, economically feasible catalyst for the production of structured lipids.

[Logistic regression analysis on coverage of influences on timely birth dose hepatitis B vaccine].

OBJECTIVE: To find out HepB vaccine timely delivery factors influencing in newborns within 24 hours, provide a basic evidences for increasing the coverage of timely HepB vaccine. METHODS: We established multinomial Logistic regression equation to analysis the factors with the investigation landform, delivery rate at hospital, occupation and education of child caretakers, ethnic,whether the child caretakers know children need vaccination and if the child caretakers bring children for vaccination. RESULTS: 234 children received timely birth dose HepB among 852 children, timely coverage rate was 27.46%. Compare with 6.71% of children delivery at home, timely coverage of children delivery at township clinic and county clinic hospitals are 46.86% and 54.05% respectively. Multinomial logistic regression analysis showed that delivery hospitals (X1), education of child caretakers (X2) were the main influencing factors to the timely birth dose HepB vaccination, the investigation landform, occupation of child caretakers, ethnic, whether the child caretakers know children need vaccination and if the child caretakers bring children for vaccination on their own have relevancy with the timely to the timely birth dose HepB vaccination. CONCLUSIONS: The strategies such as increasing the rate of delivery at hospitals and putting more funding into publicity will facilitate increasing the coverage of timely birth dose HepB vaccination.

[Distinquishment of Armillifer and a correction on pathogen misidentification from a reported case].

A worm-like specimen recovered from a patient previously identified as Armillifer sp. in the city of Yulin, Guangxi Autonomous Region. After comparative analysis of habitat (serpents as final hosts and human being as accidental intermediate host) and body size of the 4 known pathogenic pentastomid species of Armillifer (A. agkcistrodontis, A. armillatus, A. grandis and A. moniliformis) with the recovered specimen, the present authors consider that the recovered specimen has been misidentified as Armillifer sp. The recovered specimen probably belongs to a nasal leech.

[Effects of 3'-azido-deoxythymidine on telomerase activity and protein expression of hepatocarcinoma cell line SMMC-7721].

BACKGROUND & OBJECTIVE: The mechanism of inhibiting telomerase activity by telomerase inhibitors is very complex, and involves common actions of many proteins. This study was to investigate the effects of 3'-azido-deoxythymidine (AZT) on telomerase activity and protein expression of hepatocarcinoma cell line SMMC-7721, and explore possible mechanism of inhibiting telomerase activity in SMMC-7721 cells by AZT. METHODS: Optimized concentration and treatment time of AZT were detected by MTT assay. After treatment with AZT, the telomerase activity in SMMC-7721 cells was detected by real-time fluorescent quantitative TRAP (FQ-TRAP) assay; the apoptosis of SMMC-7721 cells was detected by TUNEL assay and flow cytometry (FCM); the changes of specific proteins were monitored by raman spectra assay and surface-enhanced laser desorption time of flight-mass spectrum (SELDI-TOF-MS) with protein chip assay. RESULTS: The optimized treatment time of AZT was 48 h, and the optimized concentration of AZT was 20 mmol/L. When treated with 20 mmol/L AZT for 48 h, the telomerase activity in SMMC-7721 cells was inhibited by 53.85% of control (P<0.001); apoptotic morphologic changes of SMMC-7721 cells were observed; the apoptosis rate of SMMC-7721 cells was 13.5%; 7 spectral peak of proteins were changed; 24 proteins were up-regulated and 8 were down-regulated in SMMC-7721 cells. All of the 32 distinct proteins were small molecular proteins. CONCLUSION: AZT can inhibit the telomerase activity and induce apoptosis of SMMC-7721 cells, which is related to specific small molecular proteins.