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.

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.

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.

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.

[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.

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.

[Study on efficacy and safety of lamivudine and interferon-alpha in treatment of hepatitis B virus transgenic mice with pregnancy].

OBJECTIVE: To observe the efficacy and safety of lamivudine and interferon-alpha (IFN-alpha) therapy on decrease of serum hepatitis B virus (HBV) loading of HBV transgenic mice during pregnancy. METHODS: Thirty-five transgenic mice replicating high levels of hepatitis B virus were randomly allocated into 5 groups, each of seven. Pregnant HBV transgenic mice in experimental groups 1 and 2 were given orally lamivudine [100 mg/(kg x d)] from pregnancy day 5 or 10 to delivery, mice in experimental groups 3 and 4 were given intramuscular (im) injection of IFN-alpha [5MU/(m(2) x 2d)], and mice in experimental group 5 were given normal saline at the same times. The changes of serum HBsAg, HBV DNA before and after the treatment were detected. At the same time, eighteen C57BL/6J female mice (clean level) were randomly allocated into control groups 1, 2 and 3 (each group of six), which were given lamivudine, IFN-alpha and saline respectively (the dosage was the same as that of experimental groups). The safety indexes of pregnant mice, fetus and newborns in experimental groups and control groups were observed. RESULTS: (1) The changes of serum HBsAg titers: The average serum HBsAg titers from mice in experimental group 1 were lowered significantly from (166 +/- 98) ng/ml to (82 +/- 59) ng/ml after drug treatment (P < 0.05). Those from mice in experimental group 2 were also reduced from (159 +/- 49) ng/ml to (82 +/- 60) ng/ml after drug treatment, but there was no significant difference between before and after the treatment (P > 0.05). There was no significant difference in serum HBsAg between before and after the treatment in other groups (P > 0.05). (2) The changes of HBV DNA titers: The serum HBV DNA titers from mice in experimental groups 1 and 2 were significantly decreased, from (5.50 +/- 0.86) copies/ml to (2.58 +/- 2.01) copies/ml, with significant difference between before and after the treatment (P < 0.01). Those from mice in experimental groups 3 and 4 were reduced from (5.55 +/- 0.24) copies/ml to (5.46 +/- 0.45) copies/ml, without significant difference between before and after the treatment (P > 0.05). The serum HBV DNA titer from mice in experimental group 5 was not different between before and after the treatment (P > 0.05). (3) Observation of safety indexes: no evidence in toxicity were observed in mice from experimental groups and control groups. No significant abnormalities of live fetus were observed. The postnatal survival and weight of live pups were not different between the groups (P > 0.05). (4) Comparison of the rate of dead fetus and the rate of maternal dead fetus: The rate of dead fetus and the rate of maternal dead fetus from mice in experimental groups 1 and 2 were 8.3% and 50.0% respectively, those from mice in experimental groups 3 and 4 were 8.2% and 66.7% respectively, and those from mice in experimental group 5 were 9.7% and 66.7%. There was no significant difference in the rate of dead fetus and the rate of maternal dead fetus from mice between the groups (P > 0.05). CONCLUSIONS: Effective lamivudine treatment during gestation can reduce hepatitis B viremia in pregnant HBV transgenic mice, thus lowering the risk of intrauterine infection. It has no significant adverse effect on safety of pregnant mice and their offspring.

[Study on the presence of hepatitis B virus in first-trimester villi in pregnant women with hepatitis B surface antigen positive].

OBJECTIVE: To observe the presence of hepatitis B virus (HBV) in first-trimester villi cells from pregnant women carrying HBsAg. METHODS: Immunohistochemical streptavidin-biotin peroxidase complex (SABC) staining with monoclonal HBsAg, hepatitis B core antigen (HBcAg) and PCR, in situ hybridization were used for detection of HBV infection markers in villi. Positive villi ultramicrostructures were observed with transmission electron microscope. RESULTS: HBV was detected in 8 of 25 villi of HBsAg positive pregnant women, the positive rate was 32%. HBsAg was located in the decidual cell, trophoblastic cell and villous mesenchymal cell. HBV analog was detected in rough endoplasmic reticulum of trophoblastic cell. CONCLUSIONS: HBV may infect villous cells in first-trimester pregnancy. It would be impossible for HBV to transmit the desmosomes.

Genetic susceptibility and environmental factors of esophageal cancer in Xi'an.

AIM: To analyse the role of genetic susceptibility and environmental factors in the process of esophageal cancer (EC) formation in Xi'an, China. METHODS: A hospital based case-control study, combined with molecular epidemiological method, was carried out. A total of 127 EC cases and 101 controls were interviewed with questionnaires containing demographic items, habit of tobacco smoking, alcohol drinking, and family history of EC. Polymorphism of CYP1A1 and GSTM1 of 127 EC cases and 101 controls were detected by PCR method. The interactions between genetic susceptibility and environmental factors were also discussed. RESULTS: Tobacco smoking, alcohol drinking and a family history of EC were risk factors for EC with an OR of 2.04(95% CI 1.15-3.60), 3.45(95% CI 1.74-6.91), 3.14 (95% CI 1.28-7.94), respectively. Individuals carrying CYP1A1 Val/Val genotype compared to those with CYP1A1 Ile/Ile genotype had an increased risk for EC (OR 3.35, 95% CI 1.49-7.61). GSTM1 deletion genotype was a risk factor for EC (OR1.81, 95% CI 1.03-3.18). Gene-environment interaction analysis showed that CYP1A1 Val/Val genotype, GSTM1 deletion genotype had synergetic interactions with tobacco smoking, alcohol drinking and family history of EC. CONCLUSION: Tobacco smoking, alcohol drinking and a family history of EC are risk factors for EC. CYP1A1 Val/Val and GSTM1 deletion genotypes are genetic susceptibility biomarkers for EC. There are synergic interactions between genetic susceptibility and environmental factors.

Detection of anti-HAV antibody with dot immunogold filtration assay.

AIM: To establish a rapid, sensitive and specific immunogold assay for detection of hepatitis A virus infection. METHODS: Rabbit monoclonal antibodies to anti-human IgM and IgG (Dako) were dotted on a nitrocellulose membrane (NCM) respectively to capture the human sera IgM and IgG. Then the captured antibodies would conjugate to HAV antigen, which was revealed by mouse anti-HAV IgG conjugated to gold particles. Final results were assessed by blind method. RESULTS: Sera from 96 patients with acute hepatitis were used for our study. Compared with well-recognized standard (Abbott Laboratory, USA), the sensitivity and specificity of IgM-DIGFA (self-made) were 91.3 % (42/46) and 96.0 % (48/50), and those of IgM-ELISA (Kehua, Shanghai) were 97.8 % (45/46) and 100.0 % (50/50). The identical results were produced from the study with reagents at different conditions, and the study was repeated in 15 negative sera and 10 positive sera. The serum anti-HAV IgG was tested with DIGFA at the same time. In comparison with ELISA, the sensitivity and specificity of DIGFA for IgG anti-HAV were 87.2 % (41/47) and 91.8 % (45/49), respectively. CONCLUSION: This assay can detect anti-HAV IgM and IgG simultaneously, and be done within 3 minutes. The simplicity, rapidity and specificity of the assay were useful for screening and epidemiological study.

[Psychological health status and personality of the recruits in relation with their injuries during military training].

OBJECTIVE: To analyze the relationship of the psychological status and personality to the injuries arising from military training among the recruits. METHODS: The Symptom Checklist 90 (SCL-90) and Eysenck Personality Questionnaire (EPQ) were used to evaluate the psychological health status of the recruits in an army force unit participating in the basic military training in 2002. RESULTS: The annual incidence of the injuries during the training was 9.6%. Before the training commenced, the scores of SCL-90 showed no significant difference between injured group and non-injured group (P>0.05), while measurement after the training revealed significantly higher score for psychosis in the injured group than non-injured group (P<0.01). The most frequent psychological problems before training were obsession, interpersonal relations and depression, while after training, interpersonal relations, obsession and psychosis were highlighted as the major problems. The number of recruits with the total score no less than 160 and personality type distribution were similar between the two groups. CONCLUSION: The incidence of the injuries in relation to military training are significantly decreased after the implementation of the new training protocol, and no relations of psychological problems and personality was identified with the training.

[HBsAg uptake into human trophoblasts cultured in vitro].

OBJECTIVE: To detect the entry of HBsAg into human trophoblasts cultured in vitro, to provide some clues for the mechanism responsible for HBV intrauterine transmission. METHODS: Digestion with both trypsin (0.25%) and Dnase I(0.15 U/ml) followed by repeated purification was performed to obtain a homogeneous population of trophoblast cells. The well-developed cells during longitudinal phase were randomly divided in 6 groups, which were co-incubated respectively with HBsAg-anti-HBs complex (I), co-culture of heat-inactivated sera positive for HBsAg, HBeAg, and anti-HBc and sera with high titer anti-HBs(II), heat-inactivated sera positive for HBsAg, HBeAg, and anti-HBc(III), HBsAg (IV), heat-inactivated normal sera (V), and normal medium(VI). The coverglasses mounted with confluent cells were harvested for anti-HBs immunohistochemical staining. RESULTS: The isolated cells comprised a highly purified villous trophoblast population and could meet the demands of further experiments. After co-incubation of the cells with different agents, HBsAg test yielded positive results in the cells co-incubated with the HBsAg-anti-HBs complex and in the co-cultures of heat-inactivated sera positive for HBsAg, HBeAg and anti-HBc with sera containing high-titer anti-HBs. HBsAg test was negative in all other cell groups. CONCLUSION: Human trophoblast cells could take in HBsAg in the form of HBsAg-anti-HBs complex instead of single HBsAg molecule.

[Prediction of the spatial distribution of Oncomelania snails in marshland of Jiangning County using the Ordinary Kriging].

OBJECTIVE: To explore the methods to predict the distribution of Oncomelania hupensis in the marshland of Jiangning County. METHODS: Semi-variogram was used to analyze the spatial autocorrelation of snails' distribution in the marshland of Jiangning using the Arcview8.1. A prediction map for the snails' distribution was established using the Ordinary Kriging and evaluated using the cross-validation. RESULTS: Analysis showed that the distribution of alive snails in the marshland of Jiangning in the year 2000 was auto-correlated in spatial. The semi-variogram model which was spherical demonstrated that the variation of alive snails in spatial were related with distance apart when the distance was less than 0.0301. The prediction map of the snail distribution in the marshland of Jiangning was established based on the semi-variogram using the Ordinary Kriging. The cross-validation showed that the prediction map could estimate the distribution of snails in the marshland of Jiangning correctly. And the determinant coefficient for the prediction model was 0.973. CONCLUSION: It is feasible to predict the snail distribution in the marshland of Jiangning County by using Ordinary Kringing and data from the surveillance spot.

[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.

[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.

[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.

[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.