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ObjectiveTo explore the variation rules and health risks of trihalomethane in regional drinking water， and to provide evidence for the innovative water processing technology and the optimization of drinking water quality. MethodsBased on regional drinking water sanitation monitoring， non-parametric rank sum test was used to analyze the effects of residual trihalomethane production in different periods and with disinfection methods. The United States environmental protection agency （USEPA） classic "four-step" health risk assessment model was used to evaluate the carcinogenic risk and non-carcinogenic risk of trihalomethane through drinking water exposure. ResultsThe yield of trichloromethane in wet season was 6.3 μg·L-1， which was higher than that in dry season. Compared with chlorination pretreatment， ozone pretreatment reduced the content of bromomethane dichloromethane. Compared to liquid chlorine disinfection， sodium hypochlorite treatment incresed the levels of trichloromethane and bromomethane chloride. Although the total carcinogenic and non-carcinogenic risks of trihalomethane in drinking water in the region were at safe levels， they were above the acceptable limits occasionally. The highest carcinogenic risk of trihalomethane were dichlorobromomethane and chlorodibromomethane，and the highest non-carcinogenic risk was trichloromethane. The health risk of children was 1.2 times higher than that for adults. ConclusionThe production of residual trihalomethane in drinking water in this area is relatively low， which is less harmful to the health of adults and children. Monitoring， including other disinfection byproducts， should continue and appropriate disinfection techniques for drinking water should be explored.
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Objective@#To analyze the etiological characteristics of an outbreak of Campylobacter foodborne disease in a middle school in Suzhou City, so as to provide insights into the identification of pathogenic factors of Campylobacter foodborne disease outbreaks.@*Methods@#Eighteen anal swabs from patients, 10 anal swabs from canteen workers, 43 food samples, 2 drinking water samples, 2 food original material samples and 31 environmental samples were collected, and the pathogens were rapidly screened using the gastrointestinal infection detection strip. The pathogens were isolated and cultured using the double-pore filtration membrane method, and cluster analysis of bacterial isolates was performed using pulsed field gel electrophoresis ( PFGE ). In addition, the susceptibility of Campylobacter isolates to antibiotics was tested using the Campylobacter agar dilution method.@*Results@#A total of 63 cases with Campylobacter infections were reported, and the major clinical symptoms included diarrhea ( 51 cases, 80.95% ) and fever ( 39 cases, 61.90% ), while no inpatients or deaths were found. Twelve Campylobacter-positive samples were detected, including 11 anal swabs sampled from patients and one food original material sample. Among the 11 positive anal swabs, there were 10 samples positive for Campylobacter jejuni and one sample positive for C. coli, and of the one positive food original material, C. coli was identified. PFGE analysis showed that 10 C. jejuni isolates of had 100.0% homology, and these 10 isolates were 100.0% resistant to naphthyridic acid, ciprofloxacin and tetracycline, appearing multidrug resistance.@*Conclusions@#This is an outbreak of foodborne disease caused by C. jejuni infections. Gastrointestinal infection detection strips, double-pore filtration membrane and PFGE typing are rapid and accurate to identify pathogenic factors.
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Objective To explore the ability of waist circumference (WC) to predict hypertension risk in overweight and non-overweight middle school students in Suzhou. Methods The height, weight，WC and blood pressure values of 963 students from 8 middle schools in Suzhou were collected by a combination of questionnaire survey and physical examination. Logistic regression analysis was applied to explore the correlation between WC and high blood pressure in middle school students. Results Logistic regression analysis showed that before and after adjusting for confounding factors, for every 1 cm change in WC, the risk of high blood pressure increased to 1.08 (1.03-1.14) and 1.07 (1.02-1.13) for non-overweight students, and 1.05 (1.02-1.09) and 1.05 (1.01-1.08) for overweight students, respectively. Conclusion There was a positive correlation between WC and high blood pressure in both non-overweight and overweight middle school students in Suzhou. The risk of high blood pressure was higher for non-overweight students than overweight students for every 1 cm WC change. Targeted intervention measures should be taken to reduce the prevalence rates of hypertension for middle school students.
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Discordance, such as overlap, repetition and inconsistent, of standards is one of the major problems in current standardization affair in China. Therefore, improving the unity and authority of standards through reduction of overlap, repetition and inconsistency has become the main goal of deepening standardization reform in China. This paper summarizes the discordance in public health standards in China, analyzes the major reasons and provides specific strategic suggestions through case analysis of public health standards in the ways of comparisons of same kind standards of other deparments and standards in administration documents and guidelines or technical specifications of academic associations or societies.
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<p><b>OBJECTIVE</b>To establish the three-dimensional model of human permanent premolars based on Micro-computed tomography (Micro-CT) data, and evaluate the efficiency quantitatively of two different instrumentations for root canal retreatment.</p><p><b>METHODS</b>Forty extracted permanent premolars for the reason of orthodontic treatment were collected, prepared by using ProTaper Ni-Ti files and filled by cold gutta pertscha lateral condensation technique. The subjects were scanned by Micro-CT. Forty teeth were randomly divided into two groups and retreated by K-Flexo files and ProTaper Universal retreatment system respectively. Then all subjects were scanned again, and the mean percentage of remaining filling materials and the scores of remaining filling materials presented in upper, middle and apical 1/3 of the canal were calculated.</p><p><b>RESULTS</b>Mean percentage of the remaining filling materials by K-Flexo files was lower than that by ProTaper Universal retreatment system (P=0.005). The scores demonstrated that K-Flexo files had greater efficiency than ProTaper Universal retreatment system when retreating the apical 1/3 of canal (P<0.05).</p><p><b>CONCLUSION</b>This study shows that both techniques could not remove filling materials completely.</p>
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Humans , Dental Alloys , Dental Pulp Cavity , Gutta-Percha , Nickel , Retreatment , Root Canal Filling Materials , Root Canal Preparation , Root Canal Therapy , Titanium , X-Ray MicrotomographyABSTRACT
<p><b>OBJECTIVE</b>To clone the VEGF165 gene and to construct eucaryotic expression vector, investigate the effect of overexpressed VEGF165 and transforming growth factor beta1 (TGFbeta1) on the mineral-related genes in human cells from apical papilla.</p><p><b>METHODS</b>Total RNA of ECV304 cell was extracted. The VEGF165 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR), and then was subcloned into eucaryotic expression vector pcDNA3.1hisA to construct the recombinant vector pcDNA3.1hisA-VEGF165. After being identified by digestion and DNA sequencing, pcDNA3.1hisA-VEGF165, and pcDNA3.1hisA-TGFbeta1 were transfected into human cells from apical papilla Then the efficiency of gene transfection and the expression of bone sialoprotein (BSP), dentin sialophosphoprotein (DSPP), osteocalcin (OCN), dentin matrix protein 1 (DMP1) were detected by Real-Time polymerase chain reaction (PCR).</p><p><b>RESULTS</b>Cloned VEGF165 gene sequences and inserted into expression vector of the VEGF165 sequences showed 100% homology related to the sequence in GenBank database. VEGF165 and TGFbeta1 mRNA were upregulated after transfection. The expression of DSPP mRNA were significantly increased in each experiment group (P < 0.05). The expression of OCN mRNA were increased significantly in the group transfected with pcDNA3.1hisA-TGFbeta1 and transfected with two plasmids (P < 0.05). The expression of BSP mRNA were not varying (P > 0.05), while no expression of DMP1 mRNA in each experiment group.</p><p><b>CONCLUSION</b>The recombinant eucaryotic expression vector of pcDNA3.1hisA-VEGF165 was constructed successfully. VEGF165 and TGFbeta1 can induce the expression of most mineral-related genes and they may play a key role during the differentiation of human cells from apical papilla.</p>
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Humans , Cells, Cultured , Cloning, Molecular , Genetic Vectors , Minerals , Osteocalcin , Plasmids , RNA, Messenger , Transfection , Transforming Growth Factor beta1 , Vascular Endothelial Growth Factor AABSTRACT
The cardiovascular and cerebrovascular diseases have become a main category of disease which affects human health today.It is helpful to search for its causes and main risk factors for scientific prevention and control of these diseases.Now,we have already paid close attention to effect of the airborne contaminant and meteorological factors on the cardiovascular and cerebrovascular diseases.Some reports about solo affect of two types factors have given a clear results;however,a little of unification evidences have been provided.This article reviews the solo and unification effects of pollutants and meteorological factors in the cardiovascular and cerebrovascular diseases.
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To provide a scientific basis for determining the health surveillance period of dust-exposed workers, data of a retrospective cohort study was re-analyzed with emphasis on natural course of silicosis. 33640 workers exposed to silica dust who were employed for at least 1 year from 1972 to 1974 in twenty Chinese mines or pottery factories were included as subjects, and were followed up till December 31, 1994. The cohort included subjects from 8 tungsten mines, 4 tin mines and 8 pottery factories. Our results showed that the mean latency of silicosis, for all the cases of the cohorts, was 22.9 +/- 9.8 y. 52.2 % of silicosis was diagnosed approximately 9.1 +/- 5.7 y after the dust exposure had ceased. The progression rates of silicosis from stage I to II and from stage II to III were 48.2 % and 18.5 %, and the duration was 4.1 +/- 0.2 and 6.8 +/- 0.2 y, respectively. The survival times of silicosis stage I , II and III, from the year of diagnosis to death, were 21.5, 15.8 and 6.8 years, respectively. There was 25 % of the silicosis patients whose survival time was beyond 33 y. The mean death age of all silicosis cases was 56.0 y. The death age increased to 65.6 y in the middle of 1990s. Among dust-exposed workers, subjects who became suspected case (0+ ) accounted for 15.0 %. 48.7 % of the suspected silicosis cases developed to silicosis, and the average year from the time of being suspected of the disease to the first stage of silicosis was 5.1 y. The natural characteristics, as mentioned above, varied with different mines and factories. We are led to conclude that silicosis is chronic in nature, but progress quickly. As a serious occupational disease it significantly reduces the life span of exposed workers. The study of its natural history is of importance for the development of health surveillance criteria for dust-exposed workers.
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To provide a scientific basis for determining the health surveillance period of dust-exposed workers, data of a retrospective cohort study was re-analyzed with emphasis on natural course of silicosis. 33640 workers exposed to silica dust who were employed for at least 1 year from 1972 to 1974 in twenty Chinese mines or pottery factories were included as subjects, and were followed up till December 31, 1994. The cohort included subjects from 8 tungsten mines, 4 tin mines and 8 pottery factories. Our results showed that the mean latency of silicosis, for all the cases of the cohorts, was 22.9±9.8 y. 52.2 % of silicosis was diagnosed approximately 9. 1±5.7 y after the dust exposure had ceased. The progression rates of silicosis from stage Ⅰ to Ⅱ and from stage Ⅱ to Ⅲ were 48.2% and 18.5 %, and the duration was 4.1±0.2 and 6.8±0.2 y,respectively.The survival times of silicosis stage Ⅰ , Ⅱ and Ⅲ , from the year of diagnosis to death, were 21.5,15.8 and 6.8 years, respectively. There was 25 % of the silicosis patients whose survival time was beyond 33 y. The mean death age of all silicosis cases was 56.0 y. The death age increased to 65.6y in the middle of 1990s. Among dust-exposed workers,subjects who became suspected case (0+)accounted for 15.0%. 48.7% of the suspected silicosis cases developed to silicosis, and the aver age year from the time of being suspected of the disease to the first stage of silicosis was 5.1 y. The natural characteristics, as mentioned above, varied with different mines and factories. We are led to conclude that silicosis is chronic in nature, but progress quickly. As a serious occupational disease it significantly reduces the life span of exposed workers. The study of its natural history is of importance for the development of health surveillance criteria for dust-exposed workers.