Objective Study the drug resistance trend of Helicobacter pylori (H.pylori) based on polynomial regression equation to provide reference for clinical medication.Methods A total of 3496 clinical isolates of H.pylori collected from 2007 to 2012 were used for drug sensitivity test of six common-used drugs to evaluate the resistance rate of each drug.Correlation analysis were performed on each of the two drugs.Constructed log curve,exponential curve,inverted exponential curve,polynomial curve and sigmoid curve for each kind of drug resistance rate and did regression analysis for each drug resistance rate.Results According to the results of drug sensitivity test from 2007 to 2012,amoxicillin,furazolidone and gentamicin had strong antibacterial activity to H.pylori and got a lower drug resistance rate.The resistance rate of levofloxacin and clarithromycin were increasing year by year and the resistance of metronidazole had been maintained at a high level.The predictive drug resistance rate of clarithromycin,metronidazole,levofloxacin,amoxycillin,gentamicin and furaxone in 2013 were 21.49％,95.47％,20.70％,0.10％,0.09％ and 0.10％,respectively.The results were consistent with those of H.pylori infection rate in Southeast China performed by Jianzhong Zhang.Conclusion A certain quantitative relationship exists between the time and the helicobacter resistance rate.The established model can be used to predict the future trend of H.pylori resistance rate.It can be used to guide clinical rotation,the restriction of the use of antibiotics,and to reduce the generation of antibiotic resistant bacteria.

Objective To investigate the epidemiological and molecular virological characteristics in HBV-infected patients with copositive HBsAg and anti-HBs.Methods HBV serological markers were analyzed in 52 070 specimens.The epidemiological characteristics of HBsAg and anti-HBs simultaneously positive patients (the experimental group) and HBsAg positive and auti-HBs negative patients (the control group) were compared.The S protein of HBV coding region was amplified by semi-nested PCR and sequenced.The statistical differences between the two groups were compared in different gene regions,genotypes and different clinical diagnosis.Results HBsAg was positive in 20.40％ (10 621/52 070) of all specimens.In the patients with positive HBsAg,2.48％ (263/10 621) was positive anti-HBs.The prevalence of co-positive HBsAg and auti-HBs was higher in aged 0 to 9 years and greater than or equal to 80 years than that in other age,and the prevalence of positive HBsAg and negative anti-HBs was completely opposite.The mutation rate of S protein in the experimental group was significantly higher than that in the control group (1.52％ vs 0.81％,P ＜0.01) with the mutation in the major hydrophilic region (MHR) (1.68％ vs 0.57％,P ＜0.01).The mutation rates of S protein of HBV carriers,chronic hepatitis B (CHB) patients and patients with liver cirrhosis (LC) in the experimental group were significantly higher than those in the control group (1.47％ vs 0.65％,1.28％ vs 0.84％,2.21％ vs 0.44％,P ＜0.05,respectively),except for the patients with hepatocellular carcinoma (HCC) (1.97％ vs 2.21％,P ＞ 0.05).Conclusion Co-positive HBsAg and anti-HBs in HBV-infected patients was more common in HBsAg positive patients aged 0 to 9 years and greater than or equal to 80 years than the others.Coexistence of HBsAg and anti-HBs in HBV-infected patients may relate to immune escape caused by mutation of S protein (mainly MHR).The mutation rates of S protein in the two groups of patients,co-positive HBsAg and anti-HBs and the positive HBsAg combined with negative anti-HBs,were associated with the stage of liver disease.

Objective:To explore the relationship between iodine nutrition level and iodine content in drinking water in Weinan City, Shaanxi Province.Methods:In 2017, in 10 counties (cities, districts) under the jurisdiction of Weinan City, one township (town, sub-district office, hereinafter referred to as the township) was selected in each county (city, district) according to the 5 directions of east, west, south, north, and middle. One primary school was selected in each township, and 42 children aged 8 to 10 (age and gender balanced) in each primary school were selected, urine samples and household edible salt samples were collected to test the contents of urinary iodine and salt iodine, and children's goiter was examined. Twenty-one pregnant women were selected from each township, urine samples and household edible salt samples were collected to test the contents of urinary iodine and salt iodine. At the same time, the drinking water samples of residents in townships were collected to test water iodine content. The correlation between urinary iodine, water iodine and salt iodine was analyzed by multiple linear regression.Results:Urine samples of 2 100 and 1 050 were collected from children and pregnant women, and the median urinary iodine was 254.51 and 172.55 μg/L, respectively. Edible salt samples of 2 100 and 1 050 were collected from children and pregnant women, and the median salt iodine was 24.00 and 24.44 mg/kg, respectively. A total of 232 water samples were collected, and the median water iodine was 26.53 μg/L. A total of 2 100 children's thyroids were examined, of which 65 had goiters, and the goiter rate was 3.10%. The regression model of urinary iodine and water iodine in children was statistically significant ( F = 6.48, P < 0.05), the multiple linear regression equation was = 235.52 + 1.01 x, coefficient of determination ( R2) = 0.119, 11.9% of the change of urinary iodine was related to the change of water iodine. Conclusions:Children's iodine nutrition in Weinan City is at an ultra-adequate level, while pregnant women's iodine nutrition is at an appropriate level. Eleven point nine percent of the changes in children's urinary iodine can be explained by the changes in water iodine.