Codelivery of CPT and siPHB1 with GSH/ROS Dual-Responsive Hybrid Nanoparticles Based on a [12]aneN3-Derived Lipid for Synergistic Lung Cancer Therapy.

The combination of small-interfering RNA (siRNA)-mediated gene silencing and chemotherapeutic agents for lung cancer treatment has attracted widespread attention in terms of a greater therapeutic effect, minimization of systemic toxicity, and inhibition of multiple drug resistance (MDR). In this work, three amphiphiles, CBN1-CBN3, were first designed and synthesized as a camptothecin (CPT) conjugate and gene condensation agents by the combination of CPT prodrugs and di(triazole-[12]aneN3) through the ROS-responsive phenylborate ester and different lengths of alkyl chains (with 6, 9, 12 carbon chains for CBN1-CBN3, respectively). CBN1-CBN3 were able to be self-assembled into liposomes with an average diameter in the range of 320-240 nm, showing the ability to effectively condense siRNA. Among them, CBN2, with a nine-carbon alkyl chain, displayed the best anticancer efficiency in A549 cells. In order to give nanomedicines a stealth property and PEGylation/dePEGylation transition, a GSH-responsive PEGylated TPE derivative containing a disulfide linkage (TSP) was further designed and prepared. A combination of CBN2/siRNA complexes and DOPE with TSP resulted in GSH/ROS dual-responsive lipid-polymer hybrid nanoparticles (CBN2-DP/siRNA NPs). In present GSH and H2O2, CBN2-DP/siRNA NPs were decomposed, resulting in the controlled release of CPT drug and siRNA. In vitro, CBN2-DP/siPHB1 NPs showed the best anticancer activity for suppression of about 75% of A549 cell proliferation in a serum medium. The stability of CBN2-DP/siRNA NPs was significantly prolonged in blood circulation, and they showed effective accumulation in the A549 tumor site through an enhanced permeability and retention (EPR) effect. In vivo, CBN2-DP/siPHB1 NPs demonstrated enhanced synergistic cancer therapy efficacy and tumor inhibition as high as 71.2%. This work provided a strategy for preparing lipid-polymer hybrid NPs with GSH/ROS dual-responsive properties and an intriguing method for lung cancer therapy.

Esterase-Responsive Polymeric Micelles Containing Tetraphenylethene and Poly(ethylene glycol) Moieties for Efficient Doxorubicin Delivery and Tumor Therapy.

Enzyme-responsive drug delivery systems have drawn much attention in the field of cancer theranostics due to their high sensitivity and substrate specificity under mild conditions. In this study, an amphiphilic polymer T1 is reported, which contains a tetraphenylethene unit and a poly(ethylene glycol) chain linked by an esterase-responsive phenolic ester bond. In aqueous solution, T1 formed stable micelles via self-assembly, which showed an aggregation-induced emission enhancement of 32-fold at 532 nm and a critical micelle concentration of 0.53 µM as well as esterase-responsive activity. The hydrophobic drug doxorubicin (DOX) was efficiently encapsulated into the micelles with a drug loading of 21%. In the presence of the esterase, the selective decomposition of drug-loaded T1 micelles was observed, and DOX was subsequently released with a half-life of 5 h. In vitro antitumor studies showed that T1@DOX micelles exhibited good therapeutic effects on HeLa cells, while normal cells remained mostly intact. In vivo anticancer experiments revealed that T1@DOX micelles indeed suppressed tumor growth and had reduced side effects compared to DOX·HCl. The present work showed the potential clinical application of esterase-responsive drug delivery in cancer therapy.

H2O2-Responsive amphiphilic polymer with aggregation-induced emission (AIE) for DOX delivery and tumor therapy.

Stimuli-responsive drug delivery systems (DDSs) based on amphiphilic polymers have attracted much attention. In this study, we reported an innovative H2O2-responsive amphiphilic polymer (TBP), bearing a H2O2-sensitive phenylboronic ester, AIE fluorophore tetraphenylethene (TPE) hydrophobic, and polyethylene glycol hydrophilic (PEG) moieties. TBP could self-assemble into micelles with an encapsulation efficiency as high as 74.9% for doxorubicin (DOX) in aqueous solution. In the presence of H2O2, TBP micelles was decomposed by oxidation, hydrolysis and rearrangement, leading to almost 80% DOX release from TBP@DOX micelles. TBP and the corresponding degradation products were biocompatible, while TBP@DOX micelles only displayed obvious toxicity toward cancer cells. Drug delivery process was clearly monitored by confocal laser scanning microscopic (CLSM) and flow cytometry (FCM) analysis. Moreover, in vivo anticancer study showed that TBP@DOX micelles were accumulated in tumor region of nude mice and effectively inhibited tumor growth. The results suggested that the reported H2O2-responsive amphiphilic polymer displayed great potential in drug delivery and tumor therapy.

Mother-to-infant transmission of hepatitis B virus: a Chinese experience.

Over 90% of infants infected with hepatitis B virus (HBV) caused by mother-to-infant transmission will evolve to carrier status, and this cannot be prevented until widespread administration of the HB vaccine and hepatitis B immune globulin (HBIG) is implemented. This prospective study of 214 infants born to HBsAg-positive mothers was carried out to determine if either perinatal or intrauterine HBV transmission could be effectively prevented with HBIG and the HB vaccine. Peripheral blood was collected from mothers and from newborns before they received HBIG and the HB vaccine, as well as at 0, 1, 7, 24, and 36 months after birth. Infants born with an ratio of signal to noise(S/N) value of >5 for HBsAg (ABBOTT Diagnostic Kit) were defined as mother-to-infant transmission cases, those with an S/N between 5 and 50 were classified as perinatal transmission cases, and those with an S/N >50 were considered intrauterine transmission cases. Mother-to-infant transmission occurred in approximately 4.7% (10/214) of the infants; the perinatal transmission and intrauterine transmission rates were 3.7% (8/214) and 0.9% (2/214), respectively. The risk of mother-to-infant transmission increased along with maternal HBeAg or HBVDNA levels. After 36 months of follow-up, all perinatal cases became HBsAg-negative, whereas all intrauterine transmission cases evolved into carrier status. These results indicate that infants infected via intrauterine transmission cannot be effectively protected by HBIG and HB vaccine.

High conservation of hepatitis B virus surface genes during maternal vertical transmission despite active and passive vaccination.

OBJECTIVE: Our purpose was to explore the relationship between hepatitis B virus (HBV) gene heterogeneity and maternal vertical transmission. METHODS: HBsAg-positive mothers and their neonates were selected and classified into a vertical infection neonate group (group N), a vertical infection mother group (group M) and a control group (group C). Serum HBsAg and HBeAg were examined. HBV gene fragments, including the pre-S1, and pre-S2 and S coding regions, were amplified and sequenced, and the genotype and serotype of the sequences were identified. Mutation sites and frequency of mutations were then compared between group N and group C. RESULTS: A total of 104 HBV clone sequences were obtained. All obtained sequences belonged to genotype C and serotype adr. Upon comparing sequences between group N and group C, 4 nonsynonymous mutations were found with significant difference in mutation frequency (p < 0.05). When the mothers were both HBsAg and HBeAg positive, 10 nonsynonymous mutations were found. The frequencies of these mutations were significantly lower in group N than in group C (p < 0.05). CONCLUSION: The 10 HBV mutations were negatively associated with vertical transmission when maternal HBeAg was positive. Furthermore, the species that were vertically transmitted to the fetus were mainly wild-type.

[Spatial epidemiological study on malaria epidemics in Hainan province].

OBJECTIVE: To better understand the characteristics of spatial distribution of malaria epidemics in Hainan province and to explore the relationship between malaria epidemics and environmental factors, as well to develop prediction model on malaria epidemics. METHODS: Data on Malaria and meteorological factors were collected in all 19 counties in Hainan province from May to Oct., 2000, and the proportion of land use types of these counties in this period were extracted from digital map of land use in Hainan province. Land surface temperatures (LST) were extracted from MODIS images and elevations of these counties were extracted from DEM of Hainan province. The coefficients of correlation of malaria incidences and these environmental factors were then calculated with SPSS 13.0, and negative binomial regression analysis were done using SAS 9.0. RESULTS: The incidence of malaria showed (1) positive correlations to elevation, proportion of forest land area and grassland area; (2) negative correlations to the proportion of cultivated area, urban and rural residents and to industrial enterprise area, LST; (3) no correlations to meteorological factors, proportion of water area, and unemployed land area. The prediction model of malaria which came from negative binomial regression analysis was: I (monthly, unit: 1/1,000,000) = exp (-1.672-0.399xLST). CONCLUSION: Spatial distribution of malaria epidemics was associated with some environmental factors, and prediction model of malaria epidemic could be developed with indexes which extracted from satellite remote sensing images.

[An investigation on hepatitis E virus infection status among livestock in Xi'an area].

OBJECTIVE: To explore the carrier state of hepatitis E virus(HEV) in livestock in Xi'an area. METHODS: Bile samples from swine, canine, sheep and cow were collected from a local slaughtering house. Reverse transcriptase nested polymerase chain reaction (RT-nPCR) was employed to amplify the ORF2 region in HEV RNA genome. All positive samples were sequenced and compared with data from GenBank. Homology analysis was conducted based on the outcome of sequencing. RESULTS: 194, 178, 79 and 191 bile samples from swine, canine, cow and sheep were collected. Positive rates with RT-nPCR method in these domestic animals were 4.10%, 0%, 0% and 0% respectively. Genetic distance analysis indicated that strains being identified were close to genotype IV of HEV, then genotype I, II and III in nucleic acid. Same outcome was shown by the same analysis on amino acid. CONCLUSION: Swine was the only reservoir of HEV in livestock and genotype IV was the prevalent genotype.

[The mechanism of HBV infection of human trophoblast cell].

OBJECTIVE: To observe the changes of human trophoblast cells after infected with hepatitis B virus. METHODS: HBV positive serum was used to infect human trophoblast cells in vitro. HBsAg in cell culture medium were detected by ELISA method and HBV DNA in cell culture medium and cells were detected by PCR method. HBV fluorescence polymerase chain reaction diagnose kit were used to detect the HBV DNA concentration. Ultra structure of trophoblast cells were observed with transmission electron microscopy (TEM). RESULTS: HBsAg could be detected in infection group by ELISA. Infection group cell culture medium and infection group cells were HBV DNA positive. HBV DNA concentrations in HBV infection cell culture medium in 0, 12, 36, 60, 84 h after extensively PBS washed were < 10(3), 3 x 10(4), 6 x 10(5), 5 x 10(5), 3 x 10(5) copies/mL. HBV infected trophoblast cells were found many forms of endosomes, some of which contents virus like particle. CONCLUSION: HBV might take advantage of clathrin-mediated endocytosis to enter trophoblast cell, which might lead to cell infection or across the cell bar by transcytosis.

[Evaluation on the indirect economic burden of stroke using combination of disability-adjusted life years and human capital method].

OBJECTIVE: Using the indirect economic burden of stroke in a rural population to develop rational allocation of future health resources, in Hanzhong area. METHODS: Cluster sampling which involved 53 natural villages with a total number of 75,000 people selected from the 'stroke monitoring base' of rural population was adopted in this study in the Hanzhong area. All of the 164 stroke cases were studied through a self-designed questionnaire. In calculating disability-adjusted life years (DALYs), fixed value was used in accordance with the value of GBD. The disability assessment was simplified in DALYs calculation and modified Barthel's ADL was used in disability assessment of stroke patients. In indirect economic burden analysis, the human capital method combined with DALYs was adopted with the formula as: indirect economic burden = GNP per capita x DALYs x productivity weight. RESULTS: The total DALYs were 598.88, with an average DALY of stroke as 3.65 per case. The total indirect economic burden of stroke patients in rural areas was 1,993,977.8 RMB and the average of indirect economic burden of stroke was 12,158.4 RMB per case with the largest seen in the 45-59 age group, accounted for 74.4%. CONCLUSION: In our study, the use of method in combining the human capital with DALYs was the first time being adopted in calculation of the indirect economic burden of stroke in rural population in China. The burden seemed to be much lower than literature cited from other countries. It was reasonable to evaluate indirect economic burden of stroke using method in integrating DALYs with human capital, but it was difficult to calculate the DALYs.

[A follow-up study on the efficacy of hepatitis B immunoglobulin combining hepatitis B vaccine in infants born to HBsAg positive mothers].

OBJECTIVE: To study the efficacy of hepatitis B immunoglobulin (HBIG) combining hepatitis B vaccine in high risk infants born to HBsAg positive mothers through a follow-up study program. METHODS: 184 infants (4 twin pairs) born to HBsAg carrier mothers who were consecutively recruited from December 2002 to August 2004 were followed. Major HBV serologic markers in all infants were detected by enzyme-linked immunosorbent assay (ELISA) when they were at birth, at 7th, at 24th and at 36th months. RESULTS: 7 of the 184 infants were HBsAg positive at birth, making the transplacental intrauterine infection rate of HBV as 3.80% (7/184). 125 infants were followed up at 7th months and 108 infants were followed up at 24th and 36th months. Only 2 of the 7 infants born to HBsAg-positive and HBeAg-positive mothers were persistently sera positive for HBsAg, making the chronic infection rate of HBV as 28.57%. The other 140 infants were HBsAg negative during t he follow-up period. The rate o f detectable anti-HBs i ninfants was 7.02% at birth. After infants were immunized by HBIG combining hepatitis B vaccine, the anti-HBs-positive rate reached 92% at 7th months, and gradually descended thereafter. 72.04% of the infants at 24th and 60% at 36th months showed detectable levels of anti-HBs. There was significant correlation between the produce of anti-HBs in infants and HBsAg-positive at birth while HBsAg-positive and HBeAg-positive in mothers did not relate to the produce of anti-HBs in their infants. Of 39 infants born to HBsAg-positive and HBeAg-positive mothers, 25 showed detectable levels of HBeAg. During the follow-up peirod, HBeAg was still detectable in 2 infants who were also HBsAg positive and the others all became HBeAg-negative but no infant became HBeAg-positive. CONCLUSION: The efficacy of HBIG combining hepatitis B vaccine in high risk infants was fine.

[A retrospective study on the survival rate and risk factors of mortality among 617 inpatients with ischemic stroke].

OBJECTIVE: The purpose of this study was to describe survival status and risk factors of mortality on inpatients with ischemic stroke. METHODS: 617 patients with continuous ischemic stroke cases were collected from January 2002 to June 2005 retrospectively in the Department of Neurology, Xijing Hospital, Fourth Military Medical University. In order to perceive relevant information on survival and the cause of death. All patients were followed through phone calls or mailing. The follow-up program was completed in January 2006. Kaplan-Meier methods were used for survival description. Monovariant and multivariant Cox's proportional hazard regression model were used to analyze prognostic factors on mortality. RESULTS: The longest time in the follow-up program was 47 months with 59 dropped-out cases, making the dropout rate as 9.5%. Of these patients, 80 cases died during the period of study(60 for ischemic stroke,3 for cerebral hemorrhage, 10 for cardiac disease, 7 for other cause). The median survival time was 42. 16 months. The survival rates of one-year, two-year and three-year period were 91.9%, 89.4% and 85.3%, respectively. Monovariant and multivariant Cox's proportional hazard regression model showed that the risk factors associated with mortality were old age (RR = 1.043, 95% CI: 1.013-1.074), lower Glasgow scores (RR = 0.855, 95% CI: 0.742-0.985) ,poor conscious levels(RR = 4.085, 95% CI: 2.128-7.844) and having complication (RR = 1.765, 95% CI: 1.108-2.812). CONCLUSION: The results of this study suggested that the risk factors were old age, lower Glasgow scores, poor conscious levels and having complication on mortality of ischemic stroke.

Screening cellular proteins binding to the core region of hepatitis C virus RNA genome with digoxin-labeled nucleic acids.

OBJECTIVE: To screen and identify cellular proteins binding to the core region of hepatitis C virus (HCV) RNA genome. METHODS: The plasmid pHCV core was constructed to generate in vitro transcripts of the core region of HCV RNA genome. Ultraviolet (UV) cross-linking experiment and competition analysis were performed to screen HepG2 cellular proteins, which interact with digoxin-labeled transcripts of the core region of HCV RNA genome. RNA-binding proteins were separated by immunoprecipitation, analyzed by electrophoresis on SDS-PAGE and detected by immunoblotting with anti-digoxingenin-AP. After being excised from SDS-PAGE, the proteins bands were analyzed by MALDI-TOF-MS. RESULTS: Several cellular proteins of hepG2 cell specifically bound to the core region of HCV RNA genome. The binding of cellular proteins to digoxin-labeled HCV core RNA was competed out in proportion to the increasing amount of unlabeled RNA. One of the HCV RNA-binding proteins was the B (brain) isozyme of human phosphoglycerate mutase (PGAM-B) identified by MALDI-TOF-MS. CONCLUSION: PGAM-B could specifically bind to the core region of HCV RNA genome in vitro.

Influence of meteorological factors and air pollution on the outbreak of severe acute respiratory syndrome.

OBJECTIVES: To understand the association between the outbreak of severe acute respiratory syndrome (SARS) and meteorological factors and air pollution. STUDY DESIGN: An ecological study was conducted. METHODS: Three hundred and fifty primary probable SARS cases diagnosed in mainland China between 1 January and 31 May 2003, and their 6727 close contacts during the period of their clinical symptoms before admission, were included in this study. Of the 6727 close contacts, 135 (2.0%) later developed clinical symptoms and were diagnosed as probable SARS cases. The daily meteorological data and daily air pollution data during the same SARS outbreak period in mainland China were used in the data analysis. Logistic regression analyses were conducted to explore the association between the secondary attack rate of SARS and meteorological factors and air pollution. RESULTS: In univariate analyses, daily average temperature (DAT), daily average air pressure (DAAP), and daily average relative humidity (DARH) were inversely associated with secondary attack rate (P<0.001); a significant positive association was found for daily hours of sunshine (DHS) (P<0.001). In multivariate analyses, factors associated with secondary attack rate were DAAP (odds ratio (OR)=0.53, 95% confidence interval (CI): 0.42, 0.66), DARH (OR=0.73, 95% CI: 0.53, 1.00), and daily average wind velocity (DAWV; OR=0.81, 95% CI: 0.68, 0.96). Adjustment for the onset time of a primary case led to little change in the results. In addition, in Hebei Province, a major affected area in China, only DAWV (OR=0.38, 95% CI: 0.20, 0.72) was a significant predictor of secondary attack rate with adjustment for the onset time of primary case. In Inner Mongolia, another major affected area in China, DAWV (OR=0.50, 95% CI: 0.26, 0.94) and DHS (OR=0.27, 95% CI: 0.09, 0.81) were significant predictors of secondary attack rate with adjustment for the onset time of primary case. CONCLUSIONS: Our results suggest that the SARS outbreak was significantly associated with DAWV, and that DAAP, DARH and DHS may also have influenced the SARS outbreak to some extent. However, because of ecological fallacy and uncontrolled confounding effects that may have biased the results, the association between the SARS outbreak and these meteorological factors and air pollution deserve further investigation.

Maternal hepatitis B virus (HBV) DNA positivity and sexual intercourse are associated with HBV intrauterine transmission in China: a prospective case-control study.

BACKGROUND AND AIM: Hepatitis B virus (HBV) intrauterine transmission from infected mothers contributes significantly to the persistence of the high number of HBV carriers. The aim of this study was to identify potential risk factors for HBV intrauterine transmission. METHODS: A case-control study was performed on pregnant women tested positive for HBsAg at Shaanxi Maternal and Neonatal Health Hospital, Xi'an, China, from September 2002 to October 2004. Serum samples were taken from infected women and their newborn infants and used for the detection of HBsAg. A structured standard questionnaire was used to collect demographic, medical and maternal data, and maternal HBV DNA, HBeAg, anti-hepatitis C virus and anti-hepatitis D virus were also assessed. Ten neonates validated as having HBV intrauterine transmission were selected as cases and others as controls. RESULTS: The univariate analysis indicated that maternal HBeAg positivity (odds ratio [OR] = 5.96, 95% confidence interval [CI]: 1.61-22.12), HBV DNA positivity (OR = 12.09, 95% CI: 2.97-40.17) and sexual intercourse in the second trimester (OR = 9.15, 95% CI: 1.08-202.99) were significantly associated with an increased risk for HBV intrauterine transmission, whereas contraceptive measures before pregnancy (OR = 0.21, 95%CI: 0.04-0.99) were associated with a decreased risk. The multivariate analysis, however, identified maternal HBV DNA positivity (OR = 19.18, 95%: CI: 3.26-118.73) and sexual intercourse in the second trimester (OR = 1.29, 95%: CI: 1.00-1.66) as the only independent risk factors for HBV intrauterine transmission. CONCLUSIONS: The risk of HBV intrauterine transmission increased with increased frequency of sexual intercourse. Therefore, it is concluded that maternal HBV DNA positivity and sexual intercourse in the second trimester are independent risk factors for HBV intrauterine transmission.

[Hepatitis B immunoglobulins blocking hepatitis B virus infection of trophoblast cell culture in vitro].

OBJECTIVE: To determine the role of hepatitis B Immunoglobulins (HBIG) in blocking hepatitis B virus (HBV) infection of trophoblast cell culture in vitro. METHODS: Trophoblast cells were placed in the six-well cluster dishes and incubated with 10% fetal calf serum/Dubecco's modified Eagle's Medium (10% FCS DMEM) at 37 degrees C with 5% CO2 in air. At 24 h after plating cells were subjected to experiment. Group A: cells were cultured with 0.5 ml HBV positive serum plus 3 ml 2% FCS DMEM; Group B: cells were cultured with 3 ml 2% FCS DMEM plus 0.5 ml HBV positive serum pretreated with 80 U HBIG for 30 min at 37 degrees C; Group C: cells were cultured with 3 ml 2% FCS DMEM plus 0.5 ml HBV positive serum pretreated with 40 U HBIG for 30 min at 37 degrees C; Group D: cells were cultured with 3 ml 2% FCS DMEM plus 40 U HBIG for 30 min before 0.5 ml HBV positive serum was added; Group E: cells were cultured with 40 U HBIG plus 3 ml 2% FCS DMEM; Group F: cells were cultured with HBV negative serum plus 3 ml 2% FCS DMEM. Twenty-four hours later the inoculums were removed, and the cells were extensively washed with 0.01 mol/L phosphate-buffered saline (PBS). After PBS washing, 4 ml 2% FCS DMEM was added to each well and the medium was collected every 12 hours. Enzyme-Linked Immunosorbent Assay (ELISA) method was used to detect HBsAg in culture medium (absorption value, A). HBV DNA in cell culture medium was detected by polymerase chain reaction (PCR). RESULTS: Before PBS washing, the A value of groups A, B, C, D, E, F were 2.697, 0.040, 0.102, 0.198, 0.036, 0.040 respectively. The cell culture medium in groups of A, B, C, and D were HBV DNA positive, groups of E, F were HBV DNA negative. From 12 hours to 84 hours, the average A value of groups A, B, C, D, E and F was 1.55 +/- 0.27, 0.032 +/- 0.016, 0.100 +/- 0.087, 0.052 +/- 0.044, 0.034 +/- 0.020, 0.034 +/- 0.022 respectively. The A value of groups A was significantly higher than those of other groups (P < 0.01). Cell culture medium at 84 hours of group A was HBV DNA positive and those of group B, C, D, E, F were HBV DNA negative. CONCLUSION: HBIG could effectively block HBV infection of trophoblast cell culture in vitro.

[Analysis on direct economic burden of stroke in the rural population of Hanzhong, Shaanxi Province].

OBJECTIVE: To analyze the direct economic burden of stroke in rural areas of Hanzhong. METHODS: Plan on primary interview was made after the purpose of the study had been informed to the managers of the 'surveillance field base', heads and members of the monitor assistants and detailed information was collected in the fields. Every single patient of stroke was then interviewed by the above said interviewers,using a self-designed questionnaire. 164 patients with stroke were interviewed in 53 villages with 75,000 persons lived there. The main items involved in the questionnaire would include: costs for inpatient or outpatient, reaching-out fees, fee for accommodation during treatment as outpatient, costs for treatment at home, long term medicine, caregivers and funerals as well as average income. RESULTS: The median of annual direct economic burden was 3100 Yuan for each patient in Hanzhong rural area. There were no significant differences seen between males and females or among age groups (P > 0.05). The proportion of patients with medians of annual direct economic burden of: 1000 Yuan and below, 1001-5000 Yuan, 5001-10,000 Yuan, 10,001-20,000 Yuan and over 20,001 Yuan, were 29.2%, 36.0%, 18.3%, 9.8% and 6.0% respectively. The median of annual direct economic burden of first episode stroke was 5500 Yuan for each patient, and that of stroke was 1700 Yuan for each chronic patient. The direct economic burden of first episode was significantly higher than that of stroke (P < 0.01). The costs of hospitalization, accommodation of hospitalization and treatment at home of middle-aged patients were significant higher than that of old age patients (P < 0.05). CONCLUSION: In this study, the direct economic burden of stroke was 2.9 times of the annual personal average income, which was contrary to the reports from other countries. However, the State Health Bureau bore 87.1% of the direct economic burden for urban patients, but patients in the rural areas had to pay from their own pockets. The direct economic burden of stroke was heavy in Hanzhong rural region, which called for measures to be made to decrease the direct economic burden of stroke in the region.

Remote sensing and spatial statistical analysis to predict the distribution of Oncomelania hupensis in the marshlands of China.

Remote sensing and spatial statistical analysis were employed to predict the distribution of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum, in the marshlands of Jiangning county in China. Surrogate indices related to environmental factors in the marshlands were derived from a Landsat 7 ETM+ image, and the relationship between environmental covariates and the density of O. hupensis was analyzed by stepwise regression models and ordinary kriging. Although stepwise regression demonstrated that O. hupensis densities of live snails in the marshlands related significantly to the modified soil-adjusted vegetation index, wetness and land surface temperature, the correlation coefficient was low (0.282). Therefore, spatial patterns of the regression residual were investigated by the semi-variogram method, and the spatial variation of O. hupensis density attributed to the spatial autocorrelation was estimated by ordinary kriging. The regression model of the snail density and ordinary kriging of its spatial variation were then combined with the aim of improving the prediction of O. hupensis. Following this approach, the prediction indeed improved considerably (0.852). Our results show that it is possible to predict the distribution of O. hupensis in these marshlands by using remotely sensed environmental indices, and that spatial statistical analyses are capable of improving prediction accuracy. These findings are of relevance for mapping and prediction of schistosomiasis japonica in China, and hence the national control programme.

Heterogeneity analysis of the hepatitis B virus genome in intrauterine infection.

There are many factors leading to intrauterine infection with hepatitis B virus (HBV). These factors include viral structure, HBV mutations, HBV DNA level, placenta barrier, immune status of the mother, and susceptibility of the fetus. The purpose of this study was to investigate the possible relationship between intrauterine infection with and HBV mutations of the genome of the virus. In this study, HBsAg-positive mothers were divided into two groups: intrauterine infection group and non-infection group according to whether the newborn infants were infected or not. The intrauterine infection group included four pairs of mother and their newborn infants infected in utero, and non-infection group included five HBsAg-positive mothers. HBV sequences from the two groups were analyzed and compared. The predominant strains in the mothers and infants from the intrauterine infection group were not completely consistent. This suggested that both HBV predominant strains and minority strains in the mothers could infect their infants through intrauterine transmission. Some HBV mutations probably related to intrauterine infection were examined and it was found that the frequencies of mutations were low in isolates of the virus of infants from the intrauterine infection group and high in the non-infection group. These results suggest that some strains of HBV from the mother may be transmitted selectively to the fetus in utero because of viral heterogeneity. The strains without screened mutations such as P21L in the pre-S1 region may infect the fetus more readily.

[In vitro infection of human hepatoma (Hep G2) cell line by hepatitis B virus positive serum].

OBJECTIVE: To establish a culture system of HBV positive serum infected Hep G2 cells in vitro. METHODS: Hep G2 cells were seeded into six-well cluster dishes, at 1 x 10(-6) cells per well and incubated with 3 ml 10% fetal calf serum/ Dulbecco's modified Eagle's medium (10% FCS/DMEM) at 37 degrees in 5% CO2 air. At 24 h after plating, infection group Hep G2 cells were cultured with 0.5 ml HBV positive serum, in control group HBV negative serum was used, 24 h later the inoculums was removed. The cells were then extensively washed with 0.01 mol/L phosphate-buffered saline (PBS). After washing with PBS, 4 ml 2% FCS/DMEM were added to each well and the medium was collected every 12 h. ELISA method was used to detect HBsAg in culture medium. HBV DNA in cells and culture medium was detected by PCR. RESULTS: In infection group, HBsAg could be detected from cell culture medium from 12 h (after PBS washed) to 84 h. HBV DNA could be detected by PCR in culture medium and cells. CONCLUSION: Infection of Hep G2 cells by HBV positive serum is feasible.