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Objective@#To construct Bayes discriminant function for clinical classification of common and severe Japanese encephalitis (JE) cases, and to identify cases accurately with quantitative indicators.@*Methods@#Samples of confirmed common and severe JE cases reported by the epidemic surveillance system of Gansu Provincial Center for Disease Control and Prevention from 2005 to 2017 were collected. Non-conditional logistic regression analysis and Bayes stepwise discriminant analysis were used to screen meaningful clinical indicators, so as to construct and evaluate Bayes discriminant function.@*Results@#There were 256 common JE cases and 257 severe JE cases. There were no significant differences in sex, age and occupation distributions between the two groups (P>0.05) and there was significant difference in case fatality rate (P<0.05). Non-conditional logistic regression analysis and Bayes stepwise discriminant analysis, combined with using related literature, to screen 11 clinical indicators for the construction of Bayes discriminant function. Interactive validation showed that the sensitivity of discriminant function was 71.48% (95%CI: 65.53%-76.93%) and the specificity was 73.93% (95%CI: 68.11%-79.19%). The area under ROC curve was 0.761 (95%CI: 0.720-0.803) and the total accuracy rate was 72.71%.@*Conclusion@#Bayes discriminant function can be used to identify common and severe JE cases more accurately, which is helpful for the reasonable treatment and good prognosis of JE patients.
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This study explored the association between an Alu I polymorphism at position 1,377 of the calcitonin receptor [CTR] gene and endemic fluorosis. A case-control study of 321 participants was conducted in regions with high fluorosis rates [Wushan and Fengjie counties] and those without high fluorosis rates [Yubei Qu county; termed nonfluorosis areas] in Chongqing, China. The participants were divided into three groups: the fluorosis group [FG] from areas with high fluoride exposure [121], the nonfluorosis group [NFG] from areas with high fluoride exposure [130], and a control group [CG] from areas with no excessive fluoride exposure [70]. An Alu I polymorphism in the CTR gene was genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis. The genotype distributions within each group were as follows: CC 60.33% [73/121], CT 30.58% [37/121] and TT 9.09% [11/121] for the FG; CC 74.62% [97/130], CT 21.54% [28/130] and TT 3.85% [5/130] for the NFG, and CC 68.57% [48/70], CT 31.43% [22/70] and TT 0% [0/70] for the CG. Significant differences in Alu I genotypes were observed among the groups [chi[2] = 12.317, upsilon = 4, p = 0.015]. Allele frequencies of CTR genotypes differed significantly among the groups [chi[2] = 8.859, upsilon = 2, p = 0.012]: C 75.62% [183/242] and T 24.38% [59/242] for the FG, C 85.38% [222/260] and T 14.62% [38/260] for the NFG, and C 84.29% [118/140] and T 15.71% [22/140] for the CG. An association between fluorosis and the Alu I polymorphism in the CTR gene was observed in fluoride-exposed populations
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Objective To explore the interaction of calcitonin receptor (CTR) gene polymorphisms and environmental factors in the population lived in coal-burning-borne endemic fluorosis areas in Chongqing.Methods A 1 ∶ 1 case-control study was carried out and Duping Township of Wushan County and Xinglong Township of Fengjie County of Chongqing were chosen as the endemic fluorosis areas.The observation subjects were divided into case group 121 cases and internal control group 130 cases.The Alu I polymorphism in the CTR gene was genotyped using the PCR-RFLP procedure.Logistic regression model was used to analyze the environment and genetic factors,and the interaction between genes and environment was determined according to interaction indicators.Results The rate of CC genotype in case group was lower than that of the control group [60.33％ (73/121) vs.74.62％ (97/130)],while the TT genotype was higher than that of the control group[9.09％ (11/21) vs.3.85％(5/130)].Significant differences in Alu I genotypes were observed between groups(x2 =6.57,P =0.037 ＜ 0.05; 95％CI:0.029-0.036).Allele frequencies of CTR genotypes differed significantly between groups(x2 =7.67,P =0.006 ＜ 0.01 ; OR =0.53,95 ％ CI:0.338-0.834).Urinary fluoride level (≥ 1 mg/L) was demonstrated to be a risk factor of fluorosis(OR =1.814,P =0.041 ＜ 0.05).There was a positive interaction(OR =5.530,γ =2.457) between CT + TT genotypes in CTR and the fluorosis environment of the people (urinary fluoride level ≥ 1 mg/L).Conclusions There is a certain type of interaction between CTR gene C/T polymorphism and environmental fluorine content (urinary fluoride ≥ 1 mg/L) in Chongqing population lived in coal-burning-borne fluorosis areas,and the onset of fluorosis is the result of interaction between heredity and environment.