This study investigated the mental health status of medical students in China, and analyzed the influencing factors in order to provide evidence for mental health education for medical students. A stratified cluster sampling method was used to recruit medical students from Huazhong University of Science and Technology, China. The questionnaire survey on general information and Symptom Checklist 90 (SCL-90) were used for investigation and analysis. The results showed among the 1137 valid questionnaires, 278 (24.45%) participants had SCL-90 score ≥ 160. The top three mental problems of medical students were obsessive-compulsive disorder, interpersonal sensitivity and depression in terms of the factor score ≥ 2.5 and the number of participants who reflected on the diseases. The third-year medical students had the worst mental health status, and fifth-year medical students had the best mental health status. Students from rural area had more psychological problems than those from urban area; furthermore, students with high professional satisfaction, those who were the single child of the family, non-poor students, and those whose parents had high education level had better mental health status. It was concluded that the mental health of medical students is not optimistic in China. Medical students have some mental health problems of different degrees. Factors that influence the mental health of medical students include academic pressure, professional satisfaction level and family environment.

OBJECTIVETo study the liver histopathological features of chronic HBV carriers and inactive HBsAg carriers.

METHODSLiver biopsies were performed on 189 chronic HBV carriers and 30 inactive HBsAg carriers (219 cases in total). All of them had a normal serum ALT value; they were then followed-up for more than 6 months. HBsAg and HBcAg were detected by immunohistochemistry. The circulating HBV DNA loads and serologic markers of HBV were examined at the same time. Grades of liver necrosis/inflammation and fibrosis were compared between the patients regarding their HBV DNA positivity or negativity. The relationships between the HBeAg positivity and degrees of liver histological changes were evaluated. The grades of liver necrosis/inflammation and fibrosis were compared between three age groups: younger than 18 years, 18-40, and older than 40 years.

RESULTSTwo hundred eight carriers of the total 219 (95.0%) had histological liver changes. Fifty percent (104/208) of them had mild histological changes (G0-1/S0-1), while more severe changes (G3-4 and/or S3-4) were found in 18 out of the 208. There were no significant differences in the grades of liver necrosis/inflammation and fibrosis between the chronic HBV carriers and the inactive HBsAg carriers. Among the serologic HBV DNA positive carriers, hepatic fibrosis was more severe in the HBeAg negative group than in the positive group (chi2 = 9.551, P = 0.008), but no differences of the necrosis/inflammation grades were seen between the two groups. The rate of severe fibrosis (S3-4) was 21.1% in those carriers older than 40 years but was 7.7% in patients younger than 18 years. However, no statistically significant differences in degrees of liver inflammation and fibrosis were found among the three age groups. HBcAg positive rate was 100% in the liver tissues of all the chronic HBV carriers, but only in 33.3% in the inactive HBsAg carriers.

CONCLUSIONSThe majority of our HBV carriers have liver inflammation and fibrosis. More severe histological changes were found in 8.65% of them. Liver fibrosis existed in the carriers with negative HBeAg and in those older than 40 years. HBcAg was found in hepatic tissues while their serological HBV DNA was negative.

Adolescent ; Adult ; Carrier State ; pathology ; virology ; Child ; Female ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; Hepatitis B, Chronic ; pathology ; virology ; Humans ; Liver ; pathology ; Male ; Middle Aged ; Young Adult

OBJECTIVETo study HBV preS2/S gene expression effects in mammalian cells transferred with recombinant adenoviral vector.

METHODSThe replication-deficient recombinant adenoviral vector (Ad-HBs) carrying HBV preS2/S gene were constructed by homologous recombination in bacteria. The 293 cells, Vero cells, HepG2 cells and mesenchymal stem cells (MSCs) were infected with adenoviruses. The expressions of enhanced green fluorescent protein (EGFP) were observed with fluorescence microscope and the expressions of HBsAg were detected by RT-PCR and ELISA in vitro.

RESULTSMore than 90% of 293 cells, Vero cells, HepG2 cells or MSCs expressed EGFP after transfection at the MOI of 20 and the titers of HBsAg were more than 3.229 (A value) in culture supernatant.

CONCLUSIONThe HBV preS2/S gene was not only expressed efficiently in immortalized cells, but also expressed efficiently in stem cells with the recombinant adenoviruses vector.

Adenoviridae ; genetics ; Animals ; Cell Line ; Cell Line, Tumor ; Cercopithecus aethiops ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Hepatitis B Surface Antigens ; genetics ; metabolism ; Hepatitis B virus ; genetics ; immunology ; Humans ; Microscopy, Fluorescence ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection ; Vero Cells

OBJECTIVETo explore whether hepatitis B virus (HBV) S gene-modified dendritic cells (DCs) might induce a specific cytotoxic T lymphocyte (CTL) response.

METHODSThe recombinant adenoviruses carrying HBsAg genes were prepared and used to transfect DCs generated from cord blood. The efficacy of transfection was observed through the expression of enhanced green fluorescent protein (EGFP) in DCs and the expression of HBsAg was detected by ELISA. HBV S gene-modified DCs were co-cultured with T cells from cord blood and T cells stimulating activities were detected using mixed lymphocyte reaction (MLR). The CTL assay was carried out to assess the ability of CTL lines to lyse target cells of HepG(2)22.1.5 by measuring lactate dehydrogenase (LDH) release.

RESULTSThe results showed that HBV S genes were expressed in DCs with high efficacy by recombinant adenoviral vector. DCs had a normal shape after transfection. The result of MLR showed that HBV S gene-modified DCs could effectively stimulate naive T cells to proliferate. The induced specific CTL lines could lyse target cells of HepG(2)22.1.5.

CONCLUSIONSHBV S gene-modified DCs enhanced the function to induce a specific CTL effect, showing its promise for developing anti-viral vaccine in future.

Cell Line ; Cells, Cultured ; Cytotoxicity, Immunologic ; Dendritic Cells ; immunology ; virology ; Hepatitis B ; immunology ; virology ; Hepatitis B Surface Antigens ; genetics ; immunology ; Hepatitis B virus ; genetics ; immunology ; Humans ; Lymphocyte Culture Test, Mixed ; T-Lymphocytes, Cytotoxic ; immunology

Objective To construct a recombinant adenoviral vector carrying HBcAg-HSP70 chimeric gene by homologous recombination in bacteria and to detect its expression in vitro. Methods Heat shock protein 70 gene from Mycobacterium tuberculosis were amplified by PCR and were cloned to adenoviral shuttle plasmid pAdTrack-CMV-HBsAg. Then the resultant pAdTrack-CMV-HBsAg-HSP70 was eotransfected into BJ5183 bacteria with the plasmid pAdeasy-1. The adenoviral plasmid carrying HBsAg-HSP70 gene (pAd-HBsAg-HSP70) was generated with homologous recombination in bacteria and the adenoviruses were produced in 293 cells. Several kinds of mammal cells (293 cells and Vero cells) were infected with adenoviruses and the expression of HBsAg-HSP70 was detected by RT-PCR and ELISA in vitro. Results The adenoviral plasmids pAd-HBsAg-HSP70 were obtained by selection for kanamycin resistance and confirmed by restriction endonuclease Pac Ⅰ analyses. The recombinant adenoviruses Ad-HBsAg-HSP70 were packaged successfully in 293 cells. The titer of Ad-HBsAg-HSP70 was up to 2 × 1012 pfu/L after the second passage of proliferation in 293 cells. HBsAg and HSP70 were expressed efficiently in mammal cells after infection. Conclusion The recombinant adenoviruses expressing HBsAg and HSP70 were constructed successfully which can be used further in study of gene therapy for HBV.

OBJECTIVETo establish a sequential antiviral regime and evaluate its efficacy in patients with chronic hepatitis B using a controlled trial.

METHODSSeventy-four patients with chronic hepatitis B were divided into 3 groups: 30 cases were enrolled in the sequential antiviral group in which patients received eight-week treatment with thymosin alpha1 (1.6 mg/time, subcutaneous injection, 2 times/week), six-month treatment with interferon (500 MU/ times, muscle inject, every other day) begun in the fifth week of the therapeutic course, and lamivudine treatment (100 mg/days) begun 2 months later after HBeAg seroconversion or just after the withdrawal of interferon to more than eighteen months. Fourteen cases were enrolled in combination group in which patients received six-month treatment with interferon and thymosin alpha1 simultaneously in the same manner as in sequential antiviral group. Thirty cases were enrolled in lamivudine group in which patients received more than eighteen-month treatment with lamivudine.

RESULTSThe temporary rates of HBeAg seroconversion and normalization of alanine aminotransferase (effective rate) in sequential antiviral group, combination group and lamivudine group were 76.7%, 78.6% and 13.3%, respectively. The effective rates of sequential group and combination group were very similar, and significantly higher than that of lamivudine group (P less than 0.01). Long-term efficacy rates were 76.7%, 57.1% and 16.7% among the three groups, respectively. The long-term effective rate of sequential group was relatively higher. The rate of liver damage sensitive period in sequential antiviral group and combination group was 47.7%. The time of onset was from 2 to 8 weeks after the treatment begun, earlier than that from 6 to 8 weeks after the beginning of interferon alone in the literature.

CONCLUSIONSequential antiviral therapy had much higher rates of long-term HBeAg seroconversion, undetectable HBV DNA and normalization of alanine aminotransferase with good cost-effectiveness. Its mechanism to promote the antiviral effect might be dependent on the immunoregulatory action of thymosin alpha1 in the earlier period and the specific inhibition of HBV DNA replication by lamivudine in the later period of the therapeutic course.

Adjuvants, Immunologic ; administration & dosage ; Antiviral Agents ; administration & dosage ; China ; Drug Therapy, Combination ; Hepatitis B, Chronic ; drug therapy ; Humans ; Interferon-alpha ; administration & dosage ; Lamivudine ; administration & dosage ; Thymosin ; administration & dosage ; analogs & derivatives ; Treatment Outcome

To explore the new method of discriminating Astragali Radix and Hedysari Radix by using PCR amplification of specific alleles, 30 samples of the different Astragali Radix materials and 28 samples of Hedysari Radix were collected. The total DNA of all samples were extracted, trnL-trnF sequence from Astragali Radix and Hedysari Radix was amplified by PCR and sequenced unidirectionally. These sequences were aligned by using Clustul W. Primer was designed and the PCR reaction systems including annealing temperature, dNTP, etc were optimized. All samples were amplified by PCR with specific primer, DNA from Astragali Radix would be amplified 136 bp, whereas PCR products from all of Hedysari Radix were 323 bp. This method can detect 10% of intentional Hedysari Radix DNA into Astragali Radix. PCR amplification of alleles can be used to identify Astragali Radix and Hedysari Radix successfully and is an efficient molecular marker for authentication of Astragali Radix and Hedysari Radix.
Alleles ; Astragalus Plant ; classification ; genetics ; DNA Barcoding, Taxonomic ; DNA, Plant ; genetics ; Polymerase Chain Reaction

OBJECTIVETo establish a three-dimensional finite element model of mandibular distraction osteogenesis (DO) in order to study the influence of distraction orientations to mandibular DO.

METHODSBy using the two finite element models, Von Mises stress and the displacement under different loads were measured.

RESULTSThe maximum stress in the distract equipment paralleled to the mandibular corpus was two times of that when the distract equipment paralleled to the sagittal axis. Von Mises stress concentration mainly occurred in the loading position and the condylar ante inferior. This phenomenon may lead to partial bone resorption, consequently lead to screw loose and affect the stability of distraction device. When the displacement increased in the model, the maximum stress and displacement showed linear relation.

CONCLUSIONThe counterforce produced by the device makes lateral displacement in tail. The reaction force could be reduced to a minimum degree when the traction device parallel to the sagittal axis. This study provides theoretical basis for the position of distract equipment and distraction orientations in clinical application.

Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Mandible ; Osteogenesis, Distraction

Objective To investigate the diagnostic accuracy of 64-slice spiral computed tomography(MSCT)in detecting coronary artery lesions and to analyze the impacts of coronary artery calcium on its diagnostic accuracy.Methods Sixty patients underwent 64-MSCT coronary angiography and conventional coronary angiography(CCA).Calcium scoring was estimated on plain scans.The diagnostic accuracy of MSCT to detect significant lesions(≥50%)was evaluated referring to quantitative coronary angiography(QCA).The impacts of coronary artery calcium on the diagnostic accuracy was analyzed.Results A total of 797 segments were diagnositc.The overall sensitivity,specificity,positive predictive value and negative predictive value of 64-MSCT were 96%(174/182),98%(601/615),93% (174/188),and 99%(601/609),respectively.When calcium score ≥100(Agatston score),the specificity and positive predictive value of 64-MSCT was 63%(12/19)and 81%(30/37), respectively.Conclusion In patients with no or mild coronary calcification,the 64-MSCT coronary angiography had a reliable detection of coronary artery stenoses.But severe calcification in coronary artery may degrade diagnostic specificity and positive predictive value of MSCT coronary angiography.

Objective To investigate the endurance or resistance of different bacteriophages to bubbling stress in different sampling solutions,to select the optimum sampling solution from three different ones and to select relatively stress-resistant bacteriophages from five different ones.Methods AGI-10(all glass impinger)was used as the representative for all the impingers that would bubble during operation to fulfill the bubbling experiment.Three different sampling solutions used,such as distilled water(DW),phosphatic buffer solution(PBS),and suspension medium(SM),were divided into two groups by adding olive oil(50 μl) or otherwise(0 μl).The impingers were operated 30 min at a flow rate of 7.0 L/min.The titers of bacteriophages and the volume of final sampling solutions were determined before the corrected survival probability was used to evaluate the stress resistance of several different bacteriophages.Results It was found that the survival probability of the same bacteriophage bubbling with different sampling solutions was different except for bacteriophage F2.The use of SM as the collection fluid was related to a high survival probability which remained unchanged between 50 μl and 0 μl olive oil.The corrected survival probability was 79%,77%,86%,50% and 71% for phage SM701,SM702,PhiX174,EcP1 and F2 respectively after 60 minutes of impingement at a flow rate of 7.0 L/min.Conclusion The endurance or resistance of different kinds of bacteriophages in the same sampling solution is different.SM might be an optimum sampling solution for phages.Bacteriophage SM701,SM702 and PhiX174 are more resistant to bubbling stress than EcP1 and F2.