Objective To understand the current status and influencing factors of microbial contamination of dental unit waterlines(DUWLs)of secondary and lower medical institutions in Wuhan,and provide scientific basis for for-mulating prevention and control measures.Methods A stratified convenience sampling method was adopted to con-duct questionnaire survey on 248 dental medical institutions in 15 districts of Wuhan City,DUWLs from 44 medical institutions were sampled and detected according to hospital levels.Results Among disinfection and maintenance management measures for source water and waterlines,the highest implementation rate was the installation rate of anti-suction dental handpiece(73.39％,182/248),but only 16.48％(30/182)of institutions regularly conducted the detection on anti-suction function;The lowest was the daily disinfection rate of water storage tanks(17.53％,17/97).A total of 132 water specimens were collected from 44 medical institutions,with a qualified rate of microbi-al detection of 56.06％.The qualified rates for secondary,primary,and unclassified medical institutions were 77.78％,50.00％,and 50.72％,respectively,with statistically significant differences(P＜0.05).The qualified rates of microbial detection for source water,handpiece water,and three-way syringe water were 59.09％,50.00％,and 59.09％,respectively,with no statistically significant difference(P＞0.05).Univariate analysis re-sults showed that medical institutions that regularly conducted chemical disinfection on DUWLs,understood DU-WLs waterline cleaning and disinfection standards,regularly performed microbial monitoring on diagnosis and treat-ment water,qualified source water,and flushed waterlines for 3 minutes before and after daily consultations had a higher qualified rate of microbial detection in DUWLs diagnosis and treatment water,and the differences were all statistically significant(all P＜0.05).Conclusion The contamination status of DUWLs in secondary and lower medical institutions in Wuhan is relatively serious.It is recommended to focus on strengthening the training of rele-vant regulations,installing inlet filters,regularly detecting the anti-suction function of dental handpieces,imple-menting chemical disinfection and microbial monitoring on waterlines,standardizing the implementation of flushing before and after diagnosis and treatment,and strengthening the disinfection and use management of independent wa-ter storage tanks to control contamination.

Objective To understand the current status and influencing factors of microbial contamination of dental unit waterlines(DUWLs)of secondary and lower medical institutions in Wuhan,and provide scientific basis for for-mulating prevention and control measures.Methods A stratified convenience sampling method was adopted to con-duct questionnaire survey on 248 dental medical institutions in 15 districts of Wuhan City,DUWLs from 44 medical institutions were sampled and detected according to hospital levels.Results Among disinfection and maintenance management measures for source water and waterlines,the highest implementation rate was the installation rate of anti-suction dental handpiece(73.39％,182/248),but only 16.48％(30/182)of institutions regularly conducted the detection on anti-suction function;The lowest was the daily disinfection rate of water storage tanks(17.53％,17/97).A total of 132 water specimens were collected from 44 medical institutions,with a qualified rate of microbi-al detection of 56.06％.The qualified rates for secondary,primary,and unclassified medical institutions were 77.78％,50.00％,and 50.72％,respectively,with statistically significant differences(P＜0.05).The qualified rates of microbial detection for source water,handpiece water,and three-way syringe water were 59.09％,50.00％,and 59.09％,respectively,with no statistically significant difference(P＞0.05).Univariate analysis re-sults showed that medical institutions that regularly conducted chemical disinfection on DUWLs,understood DU-WLs waterline cleaning and disinfection standards,regularly performed microbial monitoring on diagnosis and treat-ment water,qualified source water,and flushed waterlines for 3 minutes before and after daily consultations had a higher qualified rate of microbial detection in DUWLs diagnosis and treatment water,and the differences were all statistically significant(all P＜0.05).Conclusion The contamination status of DUWLs in secondary and lower medical institutions in Wuhan is relatively serious.It is recommended to focus on strengthening the training of rele-vant regulations,installing inlet filters,regularly detecting the anti-suction function of dental handpieces,imple-menting chemical disinfection and microbial monitoring on waterlines,standardizing the implementation of flushing before and after diagnosis and treatment,and strengthening the disinfection and use management of independent wa-ter storage tanks to control contamination.

Objective: To understand the distribution of tobacco retailer within 100 meters outside middle schools in Wuhan City and its impact on smoking behavior of middle school students, so as to provide basis and feasible suggestions for the development of tobacco control policy for adolescents. Methods: From February to May 2023, a multi stage stratified cluster random sampling method was used to select 20 middle schools from 4 districts in Wuhan City. To investigate the distribution of tobacco retailer within 100 metres outside the school and the sale of tobacco to minors. A total of 4 882 students were surveyed using the core questions of the 2021 Chinese Adolescent Tobacco Prevalence Questionnaire. Fisher exact probability test, Chi square test and Chi square trend test were used for statistical analysis. Results: Nearly 70.00% of middle schools had tobacco retailer within 100 metres, with an average of (1.10±0.97) per middle school. The awareness rate (100.00%) and labeling rate (87.50%) of licensed tobacco retailer were higher than those of non licensed tobacco retailer (33.33%, 16.67%) ( P <0.05). The rates of tried smoking, current smoking and buying cigarettes within 30 days were 7.13%, 1.99% and 2.54%, respectively. The rates of students who tried smoking ( 8.58 %), current smoking (2.29%) and buying cigarettes within 30 days (2.85%) in schools with tobacco retailer within 100 metres were higher than those in schools without tobacco retailer (3.79%, 1.28%, 1.83%)( χ 2=35.80, 5.37, 4.37 , P <0.05). And as the grade increased, the rates of tried smoking, current smoking and buying cigarettes among middle school students all showed an upward trend ( χ 2 trend =66.20, 36.10, 16.17, P <0.05). Conclusions Middle school students in Wuhan City have high tobacco availability. The findings suggest that school ban should be extended from 50 meters to 100 meters, and the regulatory authorities must strictly prohibit selling tobacco products to minors at tobacco retailer.

Objective: To analyze the characteristics of a norovirus outbreak in a kindergarten, and factors affecting the detoxification time, so as to provide a scientific basis for targeted control measures. Methods: On February 24,2023, the basic personal information, clinical manifestations，morbidity and treatment of 16 kindergarten cases with a norovirus outbreak in Wuhan were collected. Anal swabs were collected every 7 d after the outbreak to detect norovirus. Chisquare test was used for comparison of intergroup rates. The comparison of detoxification time between different groups was conducted by Logrank test, and the influencing factors of detoxification time in cases were analyzed by Cox multiple regression analysis. Results: From February 19-28, 2023, a total of 18 cases were reported and 16 of them participated in the detoxication time monitoring. In the first, second, third and fourth sampling after the outbreak, the positive rates were 60.00%, 100.00%, 75.00% and 0, respectively. The reverse transcriptionpolymerase chain reaction cycle threshold (Ct values) were (25.83±5.74, 28.83±5.55, 36.13±4.30), and undetected, respectively. The median time of detoxification was 19.42 d with 95%CI=(18.21-20.64)d. The results of Cox regression showed that the detoxication time was shorter in the treatment group than in the nontreatment group[HR(95%CI)=5.09(1.39-18.58), P<0.05]. Conclusion Children infected with norovirus has a long duration of detoxification,and case management, which could be shortened by drugs, and disinfection should be strengthened after the case returned to school.

AIM: To study the protective effects of baicalin on myocardial ischemia-reperfusion injury in rats. METHODS: The models of myocardial ischemia-reperfusion injury were established by occluding left anterior descending coronary artery (LAD) for 30 min, followed by reperfusion for 120 min. The rate of rise and decline of left ventricular pressure (±dp/dtmax) and end-diastolic pressure of left ventricle (LVEDP) were monitored continuously with polygraph. After reperfusion, the blood and myocardium samples were taken for determination of malondialdehyde (MDA) content, superoxide dismutase (SOD), Na+-K+-ATPase, Ca2+-ATPase activities in myocardium, creatine kinase (CK) and lactate dehydrogenase (LDH) in serum with spectrophotometer. The ultrastructural changes in ischemic myocardium were assessed by transmission electron microscope. RESULTS:dtmax and LVEDP, decreased plasma CK and LDH levels, reduced myocardial MDA content, and increased the activities of SOD, Na+-K+-ATPase, and Ca2+-ATPase in myocardium following ischemia-reperfusion. The ultrastructural injury in reperfused myocardium was relieved. CONCLUSION: Baicalin possesses a protective effect against myocardial ischnemia-reperfusion injury through scavenging oxide radicals and improving Na+-K+-ATPase and Ca2+-ATPase activities.

AIM To investigate if the protective effect of baicalin on cerebral injury induced by transient focal ischemia is related to modulation of expressions of inflammatory cytokines or adhesive molecules. METHODS Transient focal cerebral ischemia injury model in rats was induced by occlusion of the right middle cerebral artery for 2 h, followed by 24 h reperfusion. The infarct volume and neurological deficit were determined by TTC staining and the scoring method of Longa et al. The expression of intracellular adhesion molecule-1 (ICAM-1), neutrophils infiltration, and myeloperoxidase (MPO) activity in brain were measured by immunohistochemistry, hematoxylin-eosin staining, and spectrophotometer, respectively. Semiquantitative RT-PCR was employed to assess the expression of inducible nitric oxide synthase (iNOS) mRNA. The level of interleukin-1 (IL-1) in brain was assayed by radioimmunoassay. The expression of nuclear factor-κB (NF-κB) protein was evaluated by Western blot. RESULTS After transient cerebral ischemia, MPO activity and the expression of ICAM-1 in the periphery of ischemic cortex were significantly increased. Increase in iNOS mRNA and NF-κB protein expression was also shown in the ischemic area. Treatment with baicalin markedly reduced brain infarct volume and neurological deficit induced by ischemic insult, inhibited MPO activity, inflammatory cell infiltration, as well as expression of ICAM-1, iNOS and NF-κB, and decreased IL-1 level. CONCLUSION Baicalin may play a protective effect on cerebral ischemic injury through inhibiting the expression and release of the inflammatory mediators after cerebral ischemia.

Aim To investigate the protective effect of rosiglitazone on cerebral ischemia/reperfusion injury inrats. Methods Transient focal cerebral ischemia injury model in rats was induced by occlusion of the right middle cerebral artery for 2 h, followed by 24 h reperfusion. The infarct volume and neurological deficit were determined by the method of TTC staining and the Longa′s score, and used to evaluate the effect of rosiglitazone on cerebral injury. The levels of malondialdehyde (MDA), nitric oxide (NO), activities of superoxide dismutase (SOD), myeloperoxidase (MPO) and nitric oxide synthase (NOS) in brain were measured by spectrophotometer. Immunohistochemistry was employed to assess the expression of intracellular adhesion molucule-1 (ICAM-1). The histopathological change was observed after HE staining. Results Pretreatment with rosiglitazone markedly reduced brain infarct volume and neurological deficit induced by transient ischemia, inhibited MPO activity, as well as expression of ICAM-1; it also decreased NO, MDA levels and NOS activity, increased SOD activity, and improved histopathological injury. Conclusion Rosiglitazone has a protective effect on cerebral ischemia/reperfusion injury through inhibiting inflammatory process and lipid peroxidation.