Sero-epidemiological investigation on hepatitis B among permanent residents in Shenzhen area / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the infection status and epidemiological features of HBV in permanent residents of Shenzhen city.</p><p><b>METHODS</b>A multi-stage stratified random sampling method was performed for questionnaire survey to permanently-registered residents of 1-59 years old in Luohu and Baoan district of Shenzhen in 2010, and blood samples of the subjects were collected. Hepatitis B virus-related surface antigen (HBsAg) and hepatitis B virus surface antibody (anti-HBs) were detected with ELISA.</p><p><b>RESULTS</b>The total 3771 studied population showed 252 HBsAg positive and 2712 anti-HBs positive residents with the standardization prevalence as 9.73% and 72.83% , respectively. The difference of the prevalence of HBsAg and anti-HBs between males and females were not statistically significant (P > 0.05). The prevalence of HBsAg was reduced with increasing age. The differences of the prevalence of HBsAg between Shenzhen permanent registered and non-permanent registered population were not significant, but the prevalence of anti-HBs in Permanent registered residents (78.32%) was higher than in non-permanent (66.03%, χ(2) = 41.613, P < 0.001). The prevalence of HBsAg was significantly different in various occupational and educational levels. Peasants had the highest prevalence (24.13%) and medical workers had the highest prevalence of anti-HBs (89.10% ). People with junior high school education had the highest prevalence of HBsAg (12.76%) and the lowest of anti-HBs (62.45%). Population with high-level education had the highest prevalence of anti-HBs(81.00% average). The prevalence of HBsAg was over 10% in people who were born in Shenzhen and Guangdong province, and the anti-HBs was the highest in Shenzhen population with the prevalence as 74.48% and 76.47% , respectively.</p><p><b>CONCLUSION</b>In the Shenzhen resident population, the overall prevalence of HBV was lower than the average level of Guangdong province, but higher than the national wide.</p>

Applicability of a sensitive duplex real-time PCR assay for identifying B/Yamagata and B/Victoria lineages of influenza virus / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To develop a novel sensitive duplex real-time PCR assay for accurately identifying B/Yamagata and B/Victoria lineages of influenza virus type B.</p><p><b>METHODS</b>50 HA (hemagglutinin) gene sequences coding for B/Yamagata and B/Victoria lineage, respectively, were randomly downloaded for GenBank and analyzed by software MEGA. Primers and probes specific for HA gene of B/Yamagata and B/Victoria lineages were designed by Primer Primer and then applied in the duplex real-time RT-PCR method that was followed developed. Influenza virus B type and A type isolated in our laboratory and typing-confirmed by HAI method were used as reference strains to determine the specificity of this assay and the sensitivity of the duplex amplification was evaluated by viral load testing in terms of in vitro transcribed RNA copy number.</p><p><b>RESULTS</b>In 2006-2010, 793 influenza virus type B strains were isolated from 17 765 throat swab samples, among which 152 strains were differentiated as By lineage and 641 as Bv lineage by this assay. These results was agreement with that determined by HAI assay. This developed assay allows to accurately identify approximately 10(2) copies/microl for Bv and By lineage virus with intra- and inter-coefficient of variation (CV) < 3.5% and nearly 100% specificity.</p><p><b>CONCLUSIONS</b>This method provides sensitive and robust tool for routine diagnosis and on-time epidemiological examination of influenza virus, which could be applied in influenza surveillance laboratories for rapid molecular diagnosis.</p>

Measuring diet quality of labor workers in Shenzhen using Chinese diet balance index / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the overall diet quality and diet model of labor workers in Shenzhen using Chinese Diet Balance Index (DBI).</p><p><b>METHODS</b>In May 2009, 14 canteens from Baoan, Longgang and Nanshan districts were selected by stratified random sampling and 60 workers were randomly selected from each canteen by using random number method. Diet measurements were carried out among the 840 labor workers. Diet quality was evaluated by using DBI scoring and evaluating system.</p><p><b>RESULTS</b>The median values of labor workers' food intakes of cereal and meat & poultry were 483.8 and 121.7 g/d, which were more than the recommended amounts of their intakes of Chinese residents (cereal: 250 - 400 g/d, meat & poultry: 50 -70 g/d). The median values of the labor workers' intakes of fruit, dairy and eggs were 37.3, 20.6 and 23.5 g/d,which were less than recommended amounts in fruits (200 - 400 g/d), dairy (300 g/d) and eggs (25 - 50 g/d). The DBI-HBS scores of males and females in Shenzhen migrant workers were 24.4 +/- 6.1 and 22.6 +/- 6.3, respectively with a statistically significant difference (t = 4.21, P < 0.01). DBI-HBS scores of < 20 age group, 20 - 29 age group, 30 - 39 age group and > or = 40 age group in labor workers were 12.7 +/- 5.9, 11.3 +/- 6.3, 12.8 +/- 6.4 and 11.2 +/- 5.6 respectively (F = 3.67, P = 0.01). There were 7 dietary patterns among labor workers in this survey. Nearly 8.2% (68/830) of them belonged to Pattern A. Pattern B and E were the main dietary patterns, which accounted for 37.3% (310/830) and 31.0% (257/830) of the total population.</p><p><b>CONCLUSION</b>DBI can describe and evaluate the overall dietary quality and the major problem of the dietary patterns in labor workers. It is necessary to strength nutritional education to increase the intake of fruits, milk and eggs to improve nutritional status in labor workers in Shenzhen.</p>

Evaluation of effects of combination intervention model to men who have sex with men / 中华预防医学杂志

<p><b>OBJECTIVE</b>This study aimed to explore and evaluate the effects of combination intervention model conducted by Center for Disease Control and Prevention and activity place to men who have sex with men (MSM).</p><p><b>METHODS</b>To implement one-year combination intervention in 4 MSM venues during May, 2009 and April, 2010. Meanwhile, 3 similar MSM venues were chosen as control. MSM places introduced CDC to consumption crowds. Experts and volunteers sent by CDC undertook health education programme on site and condom, lubricant, pamphlet, consultation, test were provided at the same time. The intervention measures applied to control only included providing pamphlet, condom, lubricant by volunteers. Investigations were conducted among subjects of combination intervention group and control group before (111, 120 subjects) and after (105, 98 subjects) the intervention with questions related to knowledge and behavior of AIDS prevention.</p><p><b>RESULTS</b>After one-year intervention, among MSM with combination intervention, the awareness rate of knowledge level about acquired immune deficiency syndrome (AIDS) increased from 73.0% (81/111) to 91.7% (110/120), proportion of condom-use with male at last anal intercourse increased from 73.0% (81/111) to 85.0% (102/120), ratio of never-use condom with male decreased from 10.8% (11/102) to 1.7% (2/112), percentage of acquiring AIDS-related service and intervention improved significantly, acquiring condom (lubricant) increased from 70.3% (78/111) to 85.0% (102/120), acquiring peer education increased from 10.8% (12/111) to 24.2% (29/120), the proportion of acquiring counseling and testing of HIV increased from 69.4% (77/111) to 90.8% (109/120) (all P values < 0.05). The above index show no statistic difference before and after the intervention (all P values > 0.05) in control MSM venues.</p><p><b>CONCLUSION</b>Combination intervention model was an effective intervention model contributing to an increase in knowledge of AIDS prevention and decreasing high risk behavior in MSM population.</p>

Compare real-time RT-PCR with two culture methods for influenza virus detection / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Real-time RT-PCR, cell culture and embryonated eggs culture for influenza detection were compared by analyzing the data of influenza surveillance in Shenzhen in second half of 2009.</p><p><b>METHODS</b>1092 clinical samples (throat swabs) collected during second half of 2009 were tested by real-time RT-PCR, cell culture and embryonated eggs culture, and the results were analyzed by statistical methods.</p><p><b>RESULTS</b>The positive rate were 54.21%, 27.11% and 16.21% using real-time RT-PCR, cell culture and embryonated eggs culture, and the sensitive were 100%, 50% and 29.9%. The lowest dilutions of virus detected by real-time RT-PCR were 10(-2) TCID50/ml.</p><p><b>CONCLUSION</b>The sensitive of real-time RT-PCR was higher than culture and the specificity was also very high. It was more suitable for emergency detect. The sensitive of cell culture for H3N2 subtype was higher, and sensitive of embryonated eggs culture for type B was higher.</p>

A cell-based detection of ciguatoxin using sodium fluorescence probe / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a cell-based detection method of ciguatoxin using fluorescence assay.</p><p><b>METHODS</b>Mouse neuroblastoma N-2A cells were exposed to ouabain and veratridine and different concentrations of standard ciguatoxin samples (P-CTX-1) to establish the curvilinear relationship between the toxin dosage and fluorescence intensity using the sodium fluorescence probe CoroNaTM Green. The toxicity curvilinear relationship was also generated between the toxin dosage and cell survival using CCK-8 method. Based on these standard curves, the presence of ciguatoxin was detected in 33 samples of deep-sea coral fish.</p><p><b>RESULTS</b>A correlation was found between the detection results of cell-based fluorescence assay and cytotoxicity assay, whose detection limit reached 103 g/ml and 1012 g/ml, respectively. The cell-based fluorescent assay sensitivity showed a higher sensitivity than cytotoxicity assay with a 2-4 h reduction of the detection time.</p><p><b>CONCLUSIONS</b>The cell-based fluorescent assay can quickly and sensitively detect ciguatoxin and may serve as a good option for preliminary screening of the toxin.</p>

Analyses of serological and genetic characteristics on novel H1N1 influenza A virus from the infected patient in Shenzhen / 病毒学报

Analysis of serological and genetic characteristics on 2009 swine-origin influenza A (H1N1) virus (S-OIV) isolated from four patients with severe disease in Shenzhen were performed. Microneutralization assay showed that the neutralizing antibody titers of the infected patients did not exceed 1 : 20 in a short term post infection, which could not neutralize the viruses efficiently. Hemagglutination inhibition (HI) tests confirmed that the antigenicity of S-OIV from the patients was distinct from the seasonal influenza A virus, but similar to the reference strains of S-OIV. Phylogenetic and molecular analysis showed that S-OIV from the patients still belonged to the classical swine lineages and did not have the genetic characteristics of highly pathogenic influenza virus. Several amino acid residue mutations on HA protein were detected, which seemed not to affect the virulence and pathogenicity of the viruses. Further, A His 275 Tyr mutation on NA protein of a virus strain was detected, which induced the oseltamivir resistance of the virus.

Etiologic and molecular characteristics of Vibrio parahaemolyticus strains isolated from diarrheal patients in Shenzhen, in 2007-2008 / 中华流行病学杂志

Objective To study the infection status and the molecular characteristics of Vibrio parahaemolyticus isolated from diarrheal patients in Shenzhen, in 2007 to 2008 and to provide evidence for the prevention and control of diarrheal diseases caused by Vibrio parahaemolyticus. Methods More than 80 fecal specimens from four sentinel surveillance hospitals were collected and cultured each month. A total of 361 isolates of Vibrio parahaemolyticus were sero-typed and examined by real-time PCR for the presence of two major virulence genes, tdh and trh. Of 361 strains, 60 O3: K6 strains isolated from six suspected outbreaks in August, 2007 and in September, 2008 were typed by pulsed-field gel electrophoresis (PFGE). Results 4384 stool samples were detected in four sentinel surveillance hospitals and with 361 Vibrio parahaemolyticus strains isolated that belonged to 28 serotypes. Serotype O3:K6, O4:K8 and O1:KUT accounted for 67.90%, 7.50% and 6.10%, respectively. Of 361 strains, 337 strains belonged to tdh + trh- , 11 strains were tdh-trh- and 13 strains were tdh + trh +. The most prevalent serotype which caused diarrheal diseases was tdh + trh-in Shenzhen. The 60 isolates were discriminated into twenty different PFGE patterns, which belonged to three clones. Among the 60 isolates, most of the PFGE patterns of isolates from the suspected outbreak locations were identical and some strains isolated from different year were different. Conclusion Vibrio parahaemolyticus isolates in Shenzhen were dominated by O3:K6 strains. Most of these isolates carried tdh gene and few carried trh gene. Meanwhile, the identical patterns of isolates from 6 suspected outbreaks locations demonstrated that Vibrio parahaemolyticus outbreaks occurred in July 2007 and in September 2008 in Shenzhen. However, the dominated strains' PFGE patterns were different each year, indicating that the sources of Vibrio parahaemolyticus had a multiplex nature and the multiplex sources such as water, sea food and pickled products should be integrated monitored. Laboratory based surveillance of diarrheal diseases could contribute in establishing early warning system for the better prevention and control of diarrheal diseases.

A survey of Japanese encephalitis antibody migrant workers in Shenzhen 2009 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To understand the immunological status of Japanese encephalitis (JE) antibodies amongst migrant workers and to provide epidemiological basis for public health strategies on JE prevention and control in Shenzhen.</p><p><b>METHODS</b>A multi-stage random sampling method was used, and 1003 migrant workers aged 18 to 60 from 44 factories were investigated and their serum specimens were collected. The enzyme-linked immunosorbent assay (ELISA) was used to detect JE antibodies qualitatively.</p><p><b>RESULTS</b>The gross IgG seroprevalence rate for JE was 20.2% (203/1003). Sex-specified seroprevalence was 21.2% (103/485) for male and 19.3% (100/518) for female, respectively (χ(2) = 579, P > 0.05). Age-specific seropositive rates were 22.6% (12/53) for those below 20 years old, 18.7% (120/642) for those between 20-years old, 26.0% (58/223) for those between 30-years old and 15.3% (13/85) for those on or above 40 years old (χ(2) = 7.96, P > 0.05). Proportions for self-reported positive immunization, non-immunization and unclear immunization history were 22.1% (30/136), 22.1% (51/231) and 19.2% (122/636), respectively (χ(2) = 501, P > 0.05). Seroprevalence by region of origins showed that workers from Guangdong province was the highest (30.5%, 50/164), followed by workers from Guangxi (29.7%, 22/74) whilst workers from Shan(3)xi (5.4%, 2/37) had the lowest rate. Seroprevalence rate for managers (29.0%, 31/107) was higher than that of technicians (7.1%, 1/14) (χ(2) = 21.78, P < 0.05). Serological positive rate of workers with university or above educational background was the highest (32.7%, 16/49), followed by that for individuals with college degree (10.3%, 10/97) (χ(2) = 13.02, P < 0.05).</p><p><b>CONCLUSION</b>No associations are detected between JE seroprevalence and age, or sex, or self-reported immunization histories amongst migrant labor workers in Shenzhen. However, correlations between JE serological positive rate and region of origins, occupation and educational attainment are found to be significant. The gross seroprevalence of JE antibodies suggests that the level of JE antibodies amongst Shenzhen migrant workers is low and the population immunity barrier has yet to be established. It is necessary to strengthen prevention and control strategies of JE among labor workers of Shenzhen.</p>

Study on the relationship between polymorphism of adiponectin gene and risk of ischemic stroke among Han population in the Northern parts of China / 中华流行病学杂志

Objective To explore the association between polymorphisms of adiponectin gene and the risk of ischemic stroke in Han population from the Northern parts of China.Methods TaqMan probe of RT-PCR was applied to detect the genotype frequency of single nucleotide polymorphism(SNPs)(rs266729 and rs2241766)of adiponectin gene in 357 ischemic stroke cases who developed the episode at first time and with 345 healthy controls.Logistic regression analysis was used to evaluate the relationship of each genotype of SNPs and ischemic stroke.Results Mutation of rs2241766(T＞G)increased the risk of ischemic stroke among all the samples(0R=1.55,P=0.01)and it was still the risk factor of ischemic stroke when analyzed by multi-factors logistic regression after each factor was adjusted(OR=1.55,P=0.00).The polymorphism of rs266729 was not related to the risk of ischemic stroke among all the samples(OR=1.13,P=0.57).However,the genotype GG of rs266729 increased the risk of ischemic stroke among female population(OR=3.25,P=0.04).Conclusion The variance of rs2241766 in adiponectin gene was related to the risk of ischemic stroke in Han population from the Northern parts of China and the genotype GG of rs266729 could possibly increase the risk of ischemic stroke in women of Han population from the Northern parts of the country.

Comparative study of the factors in tuberculosis treatment between immigrant workers and local residents in Shenzhen / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the factors affecting the management and treatment of immigrant workers with tuberculosis, to determine the most effective measures and to provide an academic basis for tuberculosis control and prevention strategies targeting the immigrant population.</p><p><b>METHODS</b>A self-designed questionnaire was administered to 1364 immigrant workers with tuberculosis (study group) and 436 local residents (control group) with tuberculosis.</p><p><b>RESULTS</b>Whether a patient's tuberculosis status was discovered or not was related to the medical facilities initially visited, job mobility, and the individual worker's economic condition. The percentage of cases discovered was relatively low among those who made their first visit to a private clinic (39.0%), and 58.4% (796) of immigrant workers delayed their first consultation mainly due to neglecting symptoms (55.9%, 445), subjective perception of symptoms being not severe enough (19.3%, 154) to visit a physician and the inconvenience of visiting a hospital because of its being far away from home (15.8%, 47). As comparing immigrant workers with local residents, the differences of the delay reason between the two groups were statistically significant (chi(2) = 21.49, P < 0.01). And 39.9% (544) of immigrant workers and 49.1% (214) of local residents had had late confirmation. The differences of the delay reasons between the two groups were insignificant (chi(2) = 7.31, P = 0.293). And 17.6% (240) patients of immigrant workers and 13.1% (57) patients of local residents did not keep to their drug regimens in a timely fashion. The differences of the reasons between the two groups were insignificant (chi(2) = 6.66, P > 0.05). And 77.5% (1057) of immigrant workers and 31.8% (138) of local residents were considered that taking medicine in supervision spot might have impact on their lives and work. The differences of the reasons between the two groups were significant (chi(2) = 9.71, P < 0.05). All 79.2% (1080) of immigrant workers and 63.3% (276) of local residents did not obtain medicine according to prescriptions. The differences of reasons between the two groups were statistically significant (chi(2) = 24.84, P < 0.01). And 51.2% (699) of immigrant workers and 46.1% (201) of the registered population did not follow up with doctors' directions for lab tests. The differences of the reasons between the two groups were insignificant (chi(2) = 3.26, P > 0.05).</p><p><b>CONCLUSION</b>The influential factors in tuberculosis management and treatment were complex. Prevention strategies should focus on health education and promotion activities to improve awareness in seeking medical services. Also, developing and standardizing reference mechanisms for patients, and alleviating the economic burden of the workers will be critical to reduce the tuberculosis incidence.</p>

Influence of sperm from different sources on the clinical outcome of intracytoplasmic sperm injection / 中华男科学杂志

<p><b>OBJECTIVE</b>To analyze the clinical outcomes of intracytoplasmic sperm injection (ICSI) with spermatozoa from different sources.</p><p><b>METHODS</b>We retrospectively studied the rates of fertilization, clinical pregnancy, implantation, abortion, ectopic pregnancy and delivery in 682 patients treated by ICSI, who were divided according to the sperm sources into an ejaculated sperm group (ES, n = 598), a percutaneous epididymal sperm aspiration (PESA, n = 58) and a testicular sperm extraction (TSE, n = 26).</p><p><b>RESULTS</b>The fertilization rate was significantly lower in the TSE than in the ES and PESA groups (81.06% vs 87.95% and 87.82%, P < 0.05). But no statistically significant differences were observed among the ES, PESA and TSE groups in the rates of clinical pregnancy (39.46%, 48.28% and 34.62%), implantation (19.80%, 23.80% and 18.34%), abortion (13.13%, 17.86% and 11.11%), ectopic pregnancy (5.51%, 7.14% and 11.11%) and delivery (32.11%, 36.21% and 26.92%) (P > 0.05).</p><p><b>CONCLUSION</b>Although TSE-obtained sperm affect the rate of fertilization, those obtained by TSE and PESA do not obviously influence the outcome of clinical pregnancy.</p>

Study on the status of syphilis infection and its influence factors on pregnant women in Shenzhen / 中华流行病学杂志

<p><b>OBJECTIVE</b>Through questionnaire and screening, epidemiology of syphilis in pregnant women and related risk factors were studied, to develop effective policy and reducing the negative impact of the disease.</p><p><b>METHODS</b>All pregnant women who appeared at the hospitals the first time, were included, in Shenzhen city. Tolulized Red Unheated Serum Test (TRUST) method was used for primary screening and positive results were confirmed by the Treponema Pallidum Particle Agglutination (TPPA) test at the Shenzhen Center for Disease Control and Prevention (SZCDC). Positive patients were informed and treated and the pregnancies were managed accordingly at the SZCDC.</p><p><b>RESULTS</b>From 2003-2005, 418,871 (94.7%) pregnant were screened. Epidemiological and treatment data were collected from 2019 positive cases of infectious syphilis (0.48%). Among them, 94.2% were between 20 and 35 years old, with 93.6% of them had only junior high school education and 63.4% of them worked as commercial services or jobless which was significantly higher than other occupations (OR = 8.628). 89.5% of them were from other cities, significantly higher than from local residents (OR = 8.733). Gestational weeks at original diagnosis was longer and the infection rate higher.</p><p><b>CONCLUSION</b>The infection rate of syphilis in Shenzhen was still at a high level which was related to occupation, education level, place of residency, gestational weeks at first diagnosis etc. Further screening measures and early intervention were important.</p>

A case of human highly pathogenic avian influenza in Shenzhen, China: application of field epidemiological study / 中华流行病学杂志

<p><b>OBJECTIVE</b>Based on analyzing the characteristics of a case with human avian influenza and the effects of field epidemiological study.</p><p><b>METHODS</b>An emergency-response-system was started up to follow the probable human Highly Pathogenic Avian Influenza case initially detected by the "Undefined Pneumonia Surveillance System of Shenzhen". Public health professionals administered several epidemiologic investigations and giving all the contacts of the patient with a 7-day-long medical observation for temporally related influenza-like illness. Reverse transcriptase-polymerase chain reaction (RT-PCR) with primers for H5 and N1 was applied to test respiratory tract samples and/or throat swabs of the patient and all his contacts specific for the hemagglutinin gene of influenza A H5N1. Activities and strategies such as media response,notification in the public, communications with multiple related sectors, social participation and information exchange with Hong Kong were involved in field control and management.</p><p><b>RESULTS</b>The patient was a male, 31 years old,with an occupation as a truck driver in a factory,and had been residing in Shenzhen for 7 years. Started with an influenza-like syndrome, the patient received treatment on the 4th day of the onset, from a clinic and on the 6th day from a regular hospital. On the 8th day of the disease course, he was confirmed by Shenzhen Center for Disease Control and Prevention as human avian flu case and was then transferred to Intensive Care Unit (ICU). On the 83rd day of commence, the patients was healed and released from the hospital. The patient had no significant exposure to sick poultry or poultry that died from the illness before the onset of the disease. The patient and five family members lived together, but no family member was affected and no contact showed positive results for H5N1. A small food market with live poultry, which was under formal supervision and before illness the patient once visited, located near his apartment. Totally, 35 swabs from live birds and bird's coops in the market for H5 nucleic acid were tested and all were negative. The influenza H5N1 virus isolated for the case was named as A/Guangdong/02/2006 (H5N1) or GD/2/06. Phylogenetic relationships and molecular characterization analysis revealed that all the segments of the H5N1 virus named GD/2/06 still belonged to avian segments. Investigation process and control measures were released to the general public through the media. Soon after the laboratory confirmation, information was released to the society, as well as Hong Kong Center for Health Protection. Local Departments of Agriculture, Industries & Business, and Entry-Exit Inspection & Quarantine Bureau together with the Public Health Department put up combined actions. A computer-based telephone survey was initiated to investigate attitudes and knowledge of residents in town, revealing that positive atmosphere dominated and no panic existed.</p><p><b>CONCLUSION</b>Rapid laboratory diagnosis of the virus was the key for successful treatment and survival result of the case. Still, the pathogen was from birds resources. No human-to-human transmission was observed, however, source of infection was unclear. Field epidemiological study could offer special methods for the responses of emergency public health problems.</p>

Breast cancer resistance protein expression and 5-fluorouracil resistance / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance.</p><p><b>METHODS</b>MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography (HPLC) assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry (IHC) were employed to investigate the BCRP expression in breast cancer tissue specimens.</p><p><b>RESULTS</b>MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil (5-Fu) (P<0.05, n=3) in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP (r=-0.897, P<0.05, n=3). A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index (RI) of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance (R2=0.8124, P<0.01).</p><p><b>CONCLUSION</b>Resistance to 5-Fu can be mediated by BCRP. Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression.</p>

Molecular epidemiological study on oxidative DNA damage among Hasake ethnic migrants in Shenzhen / 中华流行病学杂志

objective To explore the relationship of migration and oxidative DNA damage by comparative study of oxidative DNA damage effects on people with difierent years of migration among Xinjiang Hasake ethnecity in Shenzhen.Methods Sixty Hasake residents in Shenzhen were selected,and were divided into three groups(n=20)according to the years of migration.Major changes of their life style were investigated.8-hydroxy-2'-deoxyguanosine(8-OH-dG)levels in urine were analyzed,and comet assay of peripheral blood lymphocytes conducted.Results When comparing with the group having a shorter than 1 year of stay,a significant decrease of oliveive tail moment and tail/head length in comet assay in the＞3 years group(P＜0.05)was observed 8-OH-dG level decreased significantly in 1-3 years group (P＜0.05)and＞3 years group(P＜0.01).Conclusion Our results suggested that life style changes which related to migration might reduce DNA damage in Hasake nationalities.

Analysis of pulsed-field gel electrophoresis molecular subtyping of Shigella strains in Shenzhen / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the genetic relations of Shigella isolated from Shenzhen in 2001-2006 and develop primary molecular subtyping surveillance network of Shigella.</p><p><b>METHODS</b>Chromosomal DNAs from 55 isolated in agarose were digested with the restriction enzyme Xba I, and then were analyzed by pulsed-field gel electrophoresis. Pulsed-field gel electrophoresis (PFGE) patterns were clustered using BioNumerics software.</p><p><b>RESULTS</b>All 41 distinctive PFGE patterns were identified among 55 strains. 32 strains belonged to one cluster. Differences were observed in other strains.</p><p><b>CONCLUSION</b>Both genetic-related clones and non-related clones of Shigella existed in Shenzhen. The development of PFGE molecular subtyping surveillance network would contribute to the active surveillance, outbreak investigation and source tracking for Shigellosis.</p>

Study on the relationship between breast cancer resistance protein expression and 5-fluorouracil resistance / 中华预防医学杂志

<p><b>OBJECTIVE</b>To screen breast cancer resistance protein BCRP-mediated resistance agents and to investigate the relations between BCRP expression and drug resistance.</p><p><b>METHODS</b>MT assay was performed to screen BCRP-mediated resistant agents with established BCRP expression cell model. While, the high performance liquid chromatography (HPLC) assay was administrated to measure the related dosage of intracellular retention resistant agents. The BCRP expression was investigated by both real-time RT-PCR and immunohistochemistry (IHC) assay in 140 clinical breast cancer tissue specimens. Chemosensitivity to resistant agents for clinical breast cancer tissue specimens was analyzed by MT assay. The Nonparametric variance statistics method was used to analyze the correlations between clinical breast cancer tissue of BCRP expression and drug resistance.</p><p><b>RESULTS</b>MT assay showed that increasing resistance of 5-fluorouracil (5-Fu) climbed with the increases of the BCRP expressions by 10.58 times (P < 0.05, n = 3) in cell model. HPLC assay also proved that a significant negative correlation between the intracellular retention dose of 5-Fu with different expression of BCRP (r = -0.897, P < 0.05, n = 3). Forty-seven tissue specimens of BCRP-positive expression were rapidly determined by using both real-time RT-PCR and IHC in 140 clinical breast cancer tissue specimens. Subsequently, the resistance index (RI) for 47 BCRP-positive clinical breast cancer tissues to 5-Fu was shown from 7 to 12 times compared with normal cancer-side tissues through MT assay. The statistical correlation between BCRP expression and 5-Fu resistance was observed in clinical breast cancer tissue specimens (R2 = 0.8124, P < 0.01).</p><p><b>CONCLUSION</b>This study results showed that there is a significant relationship between BCRP expression and 5-Fu resistance. Moreover, the results suggest that the chemotherapy scheme could be optimized on BCRP-positive expression breast cancer patients.</p>

An epidemiological study on the ecological environment related to Nontuberculous mycobacteria in Shenzhen city of Guangdong province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the distribution of Nontuberculous mycobacteria in the environment of Shenzhen city and its related sensitivity to drugs.</p><p><b>METHODS</b>145 samples in the environment of Shenzhen city were collected and the samples were isolated, identified and its drug sensitivity were detected according to the "Procedure of Bacteriological Determination Regulation for Tuberculous Diagnosis", issued in 1995 by the Antituberculosis Association of China.</p><p><b>RESULTS</b>All together, 53 strains of Mycobacteria were detected from the 145 sample, including 6 of them isolated from the polluted water in the hospital before disinfected, 4 from the polluted water in the hospital after disinfected, 4 from the dirt of air condition in the hospital, 34 from the polluted water in the residential area, 3 from the ocean water and 2 from the fountain. M. nonchromogenicum, M. avium, M. fortuitum, M. gordonae, M. genavense, M. chelonae and M. intracellulare were identified.</p><p><b>CONCLUSION</b>Nontuberculous mycobacteria seemed to widely exist in the environment of Shenzhen city and the ratio of drug-resistant was high. Attention should be paid to the influence of Nontuberculous mycobacteria on humans in order to formulate effective control measure.</p>

Molecular subtyping of Vibrio cholerae isolates by pulsed-field gel electrophoresis in Shenzhen from 1993 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To determine the genetic relationships between different Vibrio cholerae isolates in Shenzhen from 1993 to 2002.</p><p><b>METHODS</b>Chromosomal DNA from 60 isolates was digested in seakem gold agrose with restriction enzyme Not I and plugs were then analyzed by pulsed-field gel electrophoresis. Pulsed-field gel electrophoresis (PFGE) patterns of V. cholerae isolates were clustered using BioNumerics software.</p><p><b>RESULTS</b>39 distinctive PFGE patterns were identified with each pattern having 20 to 30 bands. Most PFGE patterns were divided into cluster A or cluster B.</p><p><b>CONCLUSION</b>The closely related pandemic clone clusters of V. cholerae strains did exist in Shenzhen. PFGE of V. cholerae could be used for active surveillance and tracking for cholerae.</p>