The infection rate of Oncomelania snails, emergence rate of Schistosoma japa-nicum cercariae, number of emerged cercariae and survival time of infected snails were observed experimentally by exposing single snails to different number of miracidia (i.e. 1, 5, 10, 20 and 40 respectively). The infection rate of snails was shown to be increased with the increasing number of miracidia. The frequency of cercaria emergence of infected snails varied significantly in different seasons and the highest was in spring and summer. No cercaria emergence was observed in winter. The average number of cercariae emerged from a single infected snail in each observation was 70.67, and through the whole lifetime in this experiment, 1,148.85?96.29. There was no significant difference in average number of emerged cercariae among the 5 groups of infected snails. The maximum number of cercariae emerged from one infected snail was 8,079. Calculated from the begining of cercaria emergence, the survival time of infected snails was in average 118.28?9.94 days, and the longest being 839 days. There was no significant difference in survival time among the 5 groups, and 94.8% infected snails died within one year.

0.05),but the efficacy index was higher in groups B and C than that in group A(P

Objective To establish a multidrug resistance cell line of human bladder tumor and study its characteristics and mechanism of muhidrug resistance. Methods Human bladder tumor cell line T24 was induced to muhidrug resistance cell line T24/ADM by intermittent administration of high dose ADM. The multidrug resistance to multianticancer agents of the ceils was evaluated by MTT assay; the expression of MDR gene was assessed by RT-PCR and P-gp expression was determined by flow cytometry. Results T24/ ADM resisted to many anti-tumor agents, and its IC50 of ADM was 16.3 times higher than that of T24. Significant overexpression of MDR gene and p-gp of the multidrug resistant cells were detected. Conclusion T24/ADM is a human muhidrug-resistant cell line, and it's drug resistance relates to the overexpression of MDR gene and p-gp.

Objective: To analyze the distribution and associated factors of high-risk genotypes of HPV in cervical infection among women in Shenzhen. Methods: The information on sociodemographic characteristics and HPV genotypes of HPV-positive women who participated cervical screening test from January 2014 to December 2016 was downloaded from Shenzhen Maternity and Child Healthcare Management Information System. According to the pathogenicity, the high-risk HPV genotypes were divided into 15 types including HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68; and there were 6 low-risk genotypes including HPV 6, 11, 42, 43, 44, and 81. Chi-square tests were applied to compare the proportions of high-risk HPV infection among women who had different sociodemographic characteristics. A non-conditional logistic regression model was used to analyze the associated factors for high-risk HPV infection. Results: In total, all HIV positives received HPV genotyping, with an average age of (38.08±9.38) years old. There were 9 979 (93.9%) high-risk and 645 (6.1%) low-risk HPV infections. The proportions of HPV infections for high-risk type in each year were 91.5%, 93.8%, and 95.6%, increasing with the screening years (χ²=54.79, P<0.001). Multivariate logistic regression analysis showed that compared with women younger than 25 years old, women in other age groups (at age 26 to 30 years, 31 to 35 years, 36 to 40 years, 41 to 45 years, and 50 years or older) had increased risks of high-risk HPV infection, with OR (95%CI) of 1.67 (1.20-2.31), 1.49 (1.09-2.03), 1.71 (1.23-2.37), 1.65 (1.19-2.31), and 1.84 (1.26-2.67), respectively; compared with the married, single women had a decreased risk of high-risk HPV infection (OR (95%CI): 0.71 (0.50-1.00)); women received HPV testing in 2015 and 2016 showed higher risk of high-risk HPV infection than those in 2014 (OR (95%CI): 1.43 (1.17-1.74) and 2.03 (1.68-2.46)). The 5 most common HPV genotypes were HPV52 (25.1%, 2 670 cases), followed by HPV16 (19.2%, 2 041 cases), HPV58 (13.3%, 1 413 cases), HPV18 (9.9%, 1 048 cases), and HPV51 (9.3%, 993 cases). Conclusion Age, marital status, and screening year were associated with high-risk HPV infections. Besides HPV16 and HPV18, the prevention and control on HPV infections for HPV52, HPV58, and HPV51 should be prioritized in Shenzhen area.

OBJECTIVETo study the type-specific prevalence of human papillomavirus (HPV) infection among women in China and to provide evidence for primary prevention and screening of cervical cancer programs.

METHODSFrom May, 2004 to April, 2007, a population-based multicenter cross-sectional study was conducted by the Cancer Hospital, Chinese Academy of Medical Sciences. Women aged 17-59 years from 4 urban areas and 4 rural areas, were screened, under both liquid based cytological and HPV tests for cervical cancer. Specimens of cervical cell were used for genotyping with Linear Array or enzyme-linked immunesorbent assay. Women showed positive in primary screening were referred to exams for further colposcopy and/or histo-pathological detections.

RESULTSA total of 6723 women were included in the data analysis. The overall prevalence of HPV infection was 15.5%. Two age-specific peaks of prevalence of HPV infection were detected among the different age groups. The first peak occurred in 17-24 year-old women in both rural areas and urban areas, while the second one occurred in 40-44 year-old women in urban areas and in 45-49 year-old women in rural areas. The prevalence of HPV infection increased with the severity of diagnosed cervical intraepithelial lesions by cytological or histo-pathological test (χ(2)=62.857, 22.113, P<0.001). HPV16 (3.2%) was seen the most common high risk HPV type, followed by HPV58 (1.8%) , HPV52 (1.5%) , HPV18 (1.0%) and HPV33 (1.0%) respectively. Other common types would include HPV66 (0.64%) , HPV42 (0.58%) and HPV53 (0.46%). The prevalence of HPV16 infection in rural women was significantly higher than that in urban women (χ(2)=4.696, P< 0.05).

CONCLUSIONPrevalence of HPV infection in Chinese women seemed to be high and with two age-specific peaks. HPV16 appeared the most commonly seen type in women with cervical lesions. HPV58 and 18 were the predominant types. Type-specific distribution of HPV infection should be taken into consideration in the development of comprehensive cervical cancer prevention strategies in China.

Adolescent ; Adult ; Alphapapillomavirus ; isolation & purification ; China ; epidemiology ; Cross-Sectional Studies ; Early Detection of Cancer ; Female ; Genotype ; Human papillomavirus 16 ; isolation & purification ; Humans ; Middle Aged ; Papillomaviridae ; isolation & purification ; Papillomavirus Infections ; epidemiology ; virology ; Prevalence ; Primary Prevention ; Rural Health ; statistics & numerical data ; Urban Health ; statistics & numerical data ; Uterine Cervical Neoplasms ; diagnosis ; Young Adult

Objective: To analyze the epidemiological genotype features of human papillomavirus (HPV) in cervical infection and their risks for cervical precancers among women in Shenzhen area. Methods: A total of 2 717 individuals ranging in age from 30~59 years were recruited in 18 community health centers of Shenzhen city from March 1 to June 15, 2015 by a cluster sampling method. The results of genotype of HPV, liquid-based cytology (LBC), colposcopy and pathology were analyzed. The clinical sensitivity and specificity as well as positive (PPV) and negative (NPV) predictive values of the combination of different HPV genotype in screening the cervical intraepithelial neoplasia (CIN) 2 and above were estimated. Results: The HPV infection rate in Shenzhen area was 15.9% (432/2 717). The most common HPV genotype was HPV52 (22.9%), followed by HPV16 (12.7%), HPV53 (10.0%), HPV51 (8.6%) and HPV58 (8.1%). Compared with HPV16/18 genotyping, HPV33/16 genotyping had a higher sensitivity (57.1% vs. 42.9%, P<0.05) and an analogous specificity (87.3% vs. 86.9%, P>0.05) in predicting CIN2+ . The sensitivity of combination of HPV33/16 genotyping and low grade squamous intraepithelial lesion (LSIL) positive tested by LBC in predicting CIN2+ was 75.0%, significantly higher than 64.3% of atypical squamous cells of undetermined significance (ASC-US) positive tested by LBC alone (P<0.05). The specificities of these two methods mentioned above in predicting CIN2+ were 83.5% and 89.2%, respectively, without statistical difference (P>0.05). Conclusions Women infected by HPV have distinct risks for CIN2+ according to different high-risk HPV genotypes. The top five risks were HPV 33, 16, 58, 56, and 68. HPV-positive women triaged by LBC LSIL+ combined with HPV33/16 genotyping may be a potential strategy for cervical cancer screening in developed urban area.