From February 2013, a novel avian influenza A H7N9 virus causing human infection with fatal outcomes has been identified in eastern China. This avian influenza A H7N9 virus is a triple reassortant of viruses that are avian-origin only and it is low pathogenic in poultry. Several characteristic amino acid mutations in HA and PB2 polymerase subunit (including G186V, Q226L and E627K substitution) have been found through sequence analysis, and these mutations probably facilitate binding to human-type receptors and efficient replication in mammals. Other mutations in NA, M2 and NS genes were also found. Although sustained human-to-human transmission has not been conclusively established, limited human-to-human transmission of the H7N9 virus remains possible. Intensified surveillance for the H7N9 virus in humans and animals is needed to answer questions about the viral origin, spread and potential threat.
Animals ; Birds ; virology ; China ; epidemiology ; Humans ; Influenza A virus ; genetics ; Influenza in Birds ; virology ; Influenza, Human ; transmission ; virology ; Mutation

China ; epidemiology ; Dust ; prevention & control ; Humans ; Silicon Dioxide ; chemistry ; Silicosis ; epidemiology ; prevention & control

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.

To investigate the effects of gambognic acid (GA) on TRAIL-induced apoptosis of cancer cells, human colon HT-29 cancer cells were treated with GA to promote apoptosis. Inhibition of the cell proliferation was measured with MTT assay and cell apoptosis was detected with formation of DNA ladders in agarose gel electrophoresis, and activation of caspase activity. The content of cytosolic reactive oxygen species (ROS) was measured with flow cytometry. The activities of Caspase-3, -8, -9 were detected using spectrophotometric assay. The levels of c-FLIP, CHOP, DR4 and DR5 in cells were tested by Western blot. Combination of GA (1 µg · mL(-1)) and TRAIL (40 ng · mL(-1)) significantly reduced proliferation and increased apoptosis of HT-29 cells over those induced by each agent alone. Percentage of apoptotic cells was increased to 45.5%. GA markedly enhanced the intracellular ROS generation. Expression of CHOP, DR4 and DR5 was up-regulated to 7.38, 5.41, and 4.85 times of the control group, respectively. GA promoted activation of Caspase-3, -8, and -9 by TRAIL (P<0.05). Furthermore, the expression of anti-apoptotic protein c-FLIP was down-regulated to 0.22 ± 0.08 times of the control group. In conclusion, GA sensitizes HT-29 cells to TRAIL-induced apoptosis by promoting ROS-activated ERS pathways, up-regulating of DR4 and DR5, and inhibiting c-FLIP expression.
Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Caspases ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Colonic Neoplasms ; metabolism ; Down-Regulation ; HT29 Cells ; Humans ; Reactive Oxygen Species ; metabolism ; TNF-Related Apoptosis-Inducing Ligand ; pharmacology ; Up-Regulation ; Xanthones ; pharmacology

This study aims to investigate the genetic characteristics of BZLF1 gene and its promoter Zp of the epidemic strains in children with primary Epstein-Barr virus (EBV)-associated diseases. Total DNA was extracted from the peripheral blood of 134 children with EBV-associated infectious mononucleosis (EBV-IM) and 32 children with EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) who were admitted to Beijing Children's Hospital from 2006 to 2011. The EBNA3C, BZLF1, and Zp genes were amplified by PCR assay. Typing of EBV was performed according to the size of the amplification product of EBNA3C gene; the amplification products of BZLF1 and Zp genes were subjected to direct sequencing, and sequence analysis was performed using BioEdit 7. 0. 9. The results were as follows: (1) EBV-1 was present in 140 samples (97.2%, 140/144) and EBV-II in 4 samples (2.8%, 4/144). (2) Three BZLF1 genotypes and their 12 subtypes (including 6 newly found subtypes) were detected in this study; there were no significant differences in the frequencies of BZLF1-A and BZLF1-B between the children with EBV-IM and EBV-HLH (P = 0.083); BZLF1-A1 was the dominant genotype in children with EBV-associated diseases; t BZLF1-A mostly had three 29-bp repeats in the first intron of BZLF1 gene, and BZLF1-B mostly had 30-bp repeats (P = 0.000), with the number of repeats varying from 1 to 13. (3) Four Zp genotypes were detected in this study, including Zp-P, Zp-V3, Zp-V4, and Zp-V1; there were no significant differences in the frequencies of these Zp genotypes between children with EBV-IM and EBV-HLH (P = 0.272, 0.252, 1.0, and 1.0, respectively). (4) The linkage analysis of BZLF1 gene and its promoter Zp showed that BZLF1-A1 was highly associated with Zp-V3 (P = 0.000), while BZLF1-B4 with Zp-P (P = 0.000); EBV-I + BZLF1 A1 was highly associated with Zp-V3 (P = 0.000), while EBV-I+BZLF1-B4 with Zp-P (P = 0.000). The conclusions are as follows: (1) BZLF1-A1 is the dominant genotype in children with EBV-associated diseases; there are mostly 29-bp repeats in the first intron of BZLF1 gene for BZLF1-A genotype and 30-bp repeats for BZLF1-B genotype. (2) Zp-P and Zp-V3 are dominant Zp genotypes of EBV in children, which shared similar detection rates. (3) BZLF1-A1 is highly associated with Zp-V3, while BZLF1-B4 with Zp-P; EBV-I+BZLF1-A1 is highly associated with Zp-V3, while EBV-I+BZLF1-B4 with Zp-P.
Child ; Child, Preschool ; China ; epidemiology ; Epstein-Barr Virus Infections ; epidemiology ; virology ; Female ; Genotype ; Herpesvirus 4, Human ; genetics ; physiology ; Humans ; Infant ; Infant, Newborn ; Introns ; genetics ; Male ; Promoter Regions, Genetic ; genetics ; Repetitive Sequences, Nucleic Acid ; genetics ; Trans-Activators ; genetics

To simulate intervention measures in controlling an outbreak of acute hemorrhagic conjunctivitis on one school campus by using the Susceptible-Infected-Recovered (SIR) model, to provide evidence for preparedness and response to the epidemic. Classical SIR model was used to model the epidemic. Malthusian exponential decline method was employed to estimate the infective coefficient β for interventions. The initial value of parameters was determined based on empirical data. The modeling was implemented using Matlab 7.1 software. Without interventions, the outbreak was expected to experience three phrases: (1)early stage (the first 5 days) in which the epidemic developed slowly and could be intervened easily; (2) rapid growing stage (6-15 days) in which the number of infected cases increased quickly and the epidemic could not be well controlled;and (3) medium and late stage (16 days and later) in which more than 90% of the susceptible persons were infected but the intervention measures failed to prevent the epidemic. With the implementation of interventions, the epidemic was predicted to be controlled in the early stage, under the SIR model. The simulation based on the SIR model kept an acceptable consistency with the actual development of epidemic after the implementation of intervention measures. The SIR model seemed effective in modeling interventions to the epidemic of acute hemorrhagic conjunctivitis in the schools.

Tibetan Herbal medicine has its own complete theory based on five sources doctrine. And the theories of "Liuwei", "Baxing" and "Shiqi Gongxiao" formed the basic core components of the property theory of Tibetan medicine. However, books and literature of Tibetan medicine have never been systematically expounded and discussed about it specially which thus will limit the further development of Tibetan medicine theory. In this thesis, we firstly introduced three basic core components of the property theory-the "Liu Wei", "Baxing", and "Shiqi Gongxiao" and their interactions as well. At the same time, the links and similarities between the theory of Tibetan medicine and Chinese medicine theory were compared. The job of the thesis done above is to lay the foundation for further systematic reveal and development of Tibetan medicine theory.
Drugs, Chinese Herbal ; chemistry ; pharmacology ; Humans ; Medicine, East Asian Traditional ; Phytotherapy ; Plants, Medicinal ; chemistry

AIM AND METHODSThe properties and sensitivity to acetylcholine of PC12 cells differentiated with nerve growth factor (NGF) have been investigated by using whole-cell clamp technique.

RESULTSWhen cultured in the presence of NGF, PC12 cells not only differentiated to resemble sympathetic neurons morphologically, but also developed electrical excitability. NGF-treated PC12 cells were highly sensitive to ACh than untreated cells. The I(Ach) proved to be generated by nAChR by pharmacological identification. Nicotinic receptor was characterized by desensitization. The macroscopic I(ACh) was inward rectified and concentration dependent.

CONCLUSIONPC12 cells are easily cultured and provides a homogenous population of cells. When culture in NGF, they differentiate to sympathetic-like neurons that contain on their surface neuronal nAChR, it can be used as good model system for studying regulation of a sympathetic neuronal nAChR.

Acetylcholine ; pharmacology ; Animals ; Cell Differentiation ; Nerve Growth Factor ; metabolism ; Neurons ; metabolism ; PC12 Cells ; Patch-Clamp Techniques ; Rats ; Receptors, Nicotinic ; metabolism

Epidemiology is a discipline characterized by complicated theory and practice.How to make the practice course function better is a topic worthy of exploring in educational reform for clinical students.The article explored the‘Student-Dominated’ Model based on ‘Problem-Based Learning ’ and ‘Team Based Learning ’ in teaching process and compared the model with the traditional one ( Teacher-Dominated Model) .Suggestions were given to further improve effectiveness of epidemiology practice courses.

OBJECTIVETo provide the basis for clinical acquired immunodeficiency syndrome (AIDS) surveillance and to avoid cross infection in hospital, we study the infection status of AIDS in Shandong province.

METHODSThe fourth-generated Akzo's ELISA kit and the fourth generated Immunoluminometric detection reagent were used for HIV antibody screening for 399 303 cases of both inpatients and outpatients from Jan. 2003 to Dec. 2011. Beijing WanTai ELISA kit and Se-marked rapid detection reagent were used for re-detection, and the positive samples were sent to the local CDC for confirming test by Western Blot.

RESULTSThe HIV-1 antibody detection results of 129 (0. 3230 per thousand) patients were confirmed to be positive, including 54 (0. 1352 per thousand) cases of outpatients and 75 (0. 1878 per thousand) cases of inpatients. HIV infection rates in outpatients from 2003 to 2011 were 0.050 per thousand, 0.030 per thousand, 0.111 per thousand, 0.120 per thousand, 0.124 per thousand, 0.113 per thousand, 0.148 per thousand, 0.201 per thousand, 0.2152 per thousand; and that in inpatients were 0. 150 per thousand, 0.089 per thousand, 0.138 per thousand, 0. 144 per thousand, 0. 104 per thousand, 0. 132 per thousand, 0. 197 per thousand, 0. 329 per thousand, 0. 313 per thousand respectively. Among these inpatients, there were 61 cases of medical patients and 14 cases of surgical patients, and most were youths and farmers.

CONCLUSIONSHIV infection rate was increasing year by year. Most inpatients whose HIV-1 antibody was positive were in the phase of AIDS. Therefore, it's very necessary to execute routine testing for inpatients and outpatients who need special examination for early diagnosis of HIV infection

Acquired Immunodeficiency Syndrome ; epidemiology ; immunology ; virology ; Adolescent ; Adult ; Aged ; China ; epidemiology ; Enzyme-Linked Immunosorbent Assay ; Female ; HIV Antibodies ; analysis ; HIV Infections ; epidemiology ; immunology ; virology ; Humans ; Male ; Middle Aged ; Young Adult