Cloning, Molecular ; Escherichia coli ; genetics ; Hepacivirus ; genetics ; Humans ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Viral Nonstructural Proteins ; biosynthesis ; genetics ; immunology

OBJECTIVETo explore the effect and mechanism of DNA polymerase β expression level on cell apoptosis and mitochondrial membrane potential induced by hydroquinone.

METHODSPolβ wild-type cells (polβ+/+), polβ overexpressed cells (polβ oe) and polβ null cells (polβ-/-) were applied as a model cell system, The effect of cell apoptosis and mitochondrial membrane potential induced by different doses of hydroquinone were analyzed by flow cytometry. The ROS and ·OH assay kit were used to examine the cellular ROS and ·OH level. The activity of cellular SOD and GSH-Px were tested by Chemiluminescence method after exposed to different concentrations of hydroquinone.

RESULTSWith the dose of hydroquinone increased, the rate of apoptosis and falling of mitochondrial membrane potential (ΔΨm) in cells were increased compared with the control. When compared with polβ+/+ cells, the rate of apoptosis in polβ-/- cells exposed to 20.00, 40.00, 80.00 µmol/L hydroquinone increased and the rate of apoptosis in polβ oe cells exposed to 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone decreased (P < 0.05). Compared with polβ+/+ cells (20.60% ± 0.57%, 37.95% ± 0.64%, 44.50% ± 1.27%, 57.55% ± 1.06%), the rate of cell which undergone mitochondrial depolarization in polβ-/- cells treated with 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone (33.60% ± 1.55%, 46.05% ± 1.77%, 52.75% ± 2.05%, 75.20% ± 0.56%) increased. The rate of cell which undergone mitochondrial depolarization in polβ oe cells exposed to 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone (16.05% ± 1.20%, 29.80% ± 1.21%, 35.15% ± 1.06%, 53.80% ± 0.85%) decreased (P < 0.05). When compared with polβ+/+ cells, fluorescent intensity of polβ-/- cells treated with different dosages of hydroquinone increased, while which of polβ oe cells decreased (P < 0.05). Compared with polβ+/+ cells, ·OH level of polβ-/- cells treated with 20.00, 40.00 µmol/L hydroquinone significantly enhanced, while which of polβ oe cells decreased sharply (P < 0.05). Under the same concentrations of hydroquinone, the activity of SOD and GSH-Px were decreased most rapidly in polβ-/- cells. The activity of SOD and GSH-Px in polβ oe cells decreased slower than in the polβ-/- cells.

CONCLUSIONHydroquinone could induced apoptosis by the generation of ROS and decrease of ΔΨm; polβ could protect cells from apoptosis induced by hydroquinone through decrease of ROS level and depolarization of mitochondria.

Animals ; Apoptosis ; drug effects ; Cells, Cultured ; DNA Polymerase beta ; metabolism ; Hydroquinones ; toxicity ; Membrane Potential, Mitochondrial ; drug effects ; Mice

OBJECTIVETo explore the effects of DNA polymerase β expression level on the genotoxicity and genetic instability induced by benzo(a)pyrene (BaP),and provide experimental the basis for further study on the carcinogenic molecular mechanism of BaP.

METHODSThree kinds of cell lines with the identical genetic background, polβ wild-type cells (polβ+/+), polβ null cells (polβ-/-) and polβ overexpression cells (polβ oe) were applied as cellular models. The oxidative damage, genotoxicity and genetic instability induced by BaP were analyzed by using different methods respectively.

RESULTSCell viability and colony forming ability of 3 kinds of cell lines exposed to BaP decreased with BaP. After treated with 5 and 20 µmol/L concentration of BaP, fluorescence intensity of polβ-/- cell line was significantly higher than that of other two cell lines (P < 0.05). When treated with 5.00 µmol/L and 20.00 µmol/L concentration of BaP, the SOD activities (76.56 ± 2.84 and 62.78 ± 4.28 U/mg pro) of polβ-/- cell line were significantly lower than that (84.85 ± 3.59) of control group and those (85.21 ± 3.20 and 76.90 ± 3.38 U/mg pro) of polβ+/+ cell line. In 20.00 µmol/L BaP group. SOD activity (82.59 ± 4.64 U/mg pro) of polβ oe cell line was lower than that (88.58 ± 6.77 U/mg pro) of control but higher than that of polβ+/+ cell line (P < 0.05). In 1.25, 5.00 and 20.00 µmol/L concentration BaP groups, the micronucleus rates of polβ-/- cell line were much higher than those of polβ+/+ cell line (P < 0.05). In 5.00 and 20.00 µmol/L concentration BaP groups, the micronucleus rates of polβ oe cell line were significantly lower than those of polβ+/+ line (P < 0.05). In 5.00 and 20.00 µmol/L concentration BaP groups, HPRT gene mutation frequencies (26.16 × 10(-6) and 37.51 × 10(-6); 27.68 × 10(-6) and 38.63 × 10(-6)) in polβ-/- cells and polβ oe cells were significantly higher than those (19.76 × 10(-6) and 24.78 × 10(-6)) of polβ+/+ cells (P < 0.05).

CONCLUSIONPolβ could play a role in protecting the cells from the genotoxicity and genetic instability induced by BaP, and the normal expression level of polβ was indispensable for maintaining genome stability.

Animals ; Benzo(a)pyrene ; toxicity ; Cell Line ; DNA Damage ; DNA Polymerase beta ; metabolism ; Mice ; Micronucleus Tests ; Mutation Rate

OBJECTIVETo explore the effects of hydroquinone (HQ) on reactive oxygen species (ROS) generation, antioxydase activities and the expression of human 8-oxo-guanine DNA glycosylase (hOGG1) mRNA in human A549 lung adenocarcinoma cell strains.

METHODSA549 cells were treated with different concentrations of HQ. Cell survival was determined by methyl thiazolyl tetrazolium (MTT). Changes of ROS were detected by fluorescent probe. The contents of malonaldehyde and activities of antioxydase were determined through colorimetry. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the level of hOGG1 mRNA.

RESULTSWith the increased concentration of HQ, the findings were as follows. (1) The absorbance value of A549 cell decreased. There was significant difference between 160 micromol/L (0.584+/-0.098) and 320 micromol/L (0.328+/-0.066) of HQ (q=5.56 and 9.07, P<0.05) with the control group (0.989+/-0.150), and the cell survival rate were less than 80%. (2) The ROS in A549 cell increased. 40 micromol/L (39.80+/-4.15) and 80 micromol/L (101.99+/-9.45) had statistical significance (q=10.74 and 30.32, P<0.05) with the control group (5.71+/-0.50). (3) It was found that the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) decreased and malonaldehyde (MDA) increased. Compared with the control group [(25.62+/-0.28) U/mg prot and (38.97+/-2.61) U/mg prot], the activities of SOD and GSH-Px had a significant decrease (q=12.17 and 8.78, P<0.05) in 80 micromol/L [(22.93+/-0.56) U/mg prot and (25.60+/-2.31) U/mg prot]. And MDA had a significant increase (q=10.90 and 15.49, P<0.05) in 40 micromol/L [(1.07+/-0.01) nmol/mg prot] and 80 micromol/L [(1.19+/-0.08) nmol/mg prot] as compared with the control group [(0.77+/-0.04) nmol/mg prot]. The decrease of SOD (r=-0.95, F=20.00, P=0.04) and GSH-Px activities (r=-0.99, F=115.48, P=0.01) and the increase of MDA contents (r=0.96, F=21.31, P=0.04) all had a dose-response relationship. (4) RT-PCR results showed that the expression of hOGG1 mRNA decreased. The significant difference was observed between the expression of hOGG1 mRNA in 80 micromol/L (0.478+/-0.017) (q=11.70, P<0.05) with the control group (0.715+/-0.038).

CONCLUSIONThis study suggests that HQ could induce oxidative damage and changes of the expression of hOGG1 mRNA in A549 cells.

Cell Line, Tumor ; DNA Glycosylases ; genetics ; Down-Regulation ; Gene Expression ; Gene Expression Regulation, Enzymologic ; drug effects ; Humans ; Hydroquinones ; toxicity ; RNA, Messenger ; genetics

OBJECTIVETo explore the effects of down- regulated hOGG1 gene expression on cytotoxicity and genotoxicity of hydroquinone.

METHODSA549 cells and A549-R cells with down- regulated hOGG1 gene were treated with different concentrations of hydroquinone (0, 5, 10, 20, 40 and 80 μmol/L). The cellular sensitivity and contents of ROS were measured by MTT assay and fluorescence method, respectively. The chromosome damage was measured by micronucleus test. The DNA damage and repair were examined using comet assay in both cells.

RESULTSThe cell viability decreased with increasing concentration of hydroquinone. The IC₅₀ of hydroquinone was 160.49 and 228.42 μmol/L in hOGG1 deficient A549-R cell and in A549 cell respectively (P < 0.05). When the dose of hydroquinone reached 5 micromol/L and above, the contents of ROS and the rate of micronucleated cells in A549-R cells were significantly higher than in A549 (P < 0.05) cells. At the same time, the comet rate and OTM in A549-R cells were significantly higher compared with A549 cells at 5 micromol/L and above in a dose-response way (P < 0.05). Furthermore, in DNA repair assay, A549-R cells with down- regulated hOGG1 gene were more difficult to repair than A549 cells. In A549-R cells, the comet rate and OTM reduced significantly until after 2 h repair time and even after 3 h the DNA damage was not repaired completely.

CONCLUSIONOxidative damage may be one of the toxicological mechanisms of hydroquinone, and hOGG1 deficiency could increase sensitivity of A549-R cells to hydroquinone.

Cell Line, Tumor ; Cell Survival ; Comet Assay ; DNA Damage ; DNA Glycosylases ; genetics ; Down-Regulation ; Humans ; Hydroquinones ; toxicity ; Oxidative Stress

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

OBJECTIVETo understand the etiology of pneumonia in hospitalized patients less than 3 years of age.

METHODSA total of 316 children with pneumonia admitted to the Children's Hospital of Suzhou University in Jiangsu Province from March, 2006 to January, 2007 were enrolled in this study. Sputum samples were obtained by deep nasotracheal aspiration technique for bacterial and viral cultures.

RESULTSOf the 316 samples, specific microbial etiology was obtained in 192 cases (60.8%). Bacterial infection was found in 162 cases (51.3 %), viral infection in 19 cases (6.3%)and compound infection with virus and bacteria in 11 cases (3.5 %). Haemophilus influenzae was the most common agent (46 cases; 14.6%) in bacterial infection, followed by Streptococcus pneumoniae (32 cases; 10.1%). Respiratory syncycial virus (RSV) was the most common agent (12 cases; 4.0%) in viral infection, followed by adenovirus (11 cases; 3.6%).

CONCLUSIONSBacterial infection was a leading cause of pneumonia in children less than 3 years of age in Suzhou area. Haemophilus influenzae was the most common agent, followed by Streptococcus pneumoniae.

Child, Preschool ; Hospitalization ; Humans ; Infant ; Infant, Newborn ; Pneumonia ; etiology ; Sputum ; microbiology

A water-soluble compound, sodium formononetin-3'-sulfonate with good lipid-lowering and liver-protection activities was synthesized. It was synthesized by sulfonation reaction, and its structure was characterized by IR, NMR and elemental analyses. The solubility of sodium formononetin-3'-sulfonate in water and n-octanol/water partition coefficient were determined by UV spectrophotometry. The lipid-lowering and liver-protection activities of sodium formononetin-3'-sulfonate were tested by using rat's high fat model induce by feeding with high fat food. The results showed that sodium formononetin-3'-sulfonate not only had favorable water, solubility but also had good lipid-lowering and liver-protection activities.
Adipose Tissue ; drug effects ; Alanine Transaminase ; metabolism ; Animals ; Aspartate Aminotransferases ; metabolism ; Cholesterol ; blood ; Cholesterol, HDL ; blood ; Cholesterol, LDL ; blood ; Hypolipidemic Agents ; chemical synthesis ; chemistry ; pharmacology ; Isoflavones ; chemical synthesis ; chemistry ; pharmacology ; Lipids ; blood ; Liver ; enzymology ; pathology ; Male ; Molecular Structure ; Protective Agents ; chemical synthesis ; chemistry ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Solubility ; Triglycerides ; blood

Objective To describe the epidemiologieal features of viral encephalitis and burden of Japanese encephalitis (JE),and to identify potential strategies for effective JE control measures,using data from the Viral Encephalitis Surveillance Program (VESP) launched in Ankang,Baoji,and Weinan prefectures,Shaanxi province.Methods Data was gathered from sentinel hospitals reporting system on all the viral encephalitis (VE) eases identified between June 2005 and May 2007.County Center for Disease Control and Prevention (CDC) investigated the cases,drawing blood and cerebrospinal fluid (CSF) samples from the hospitals,and testing IgM antibody against JE using ELISA.We used Epi Data and Excel for data entry and analysis.Results A total of 1097 VEs were reported and 1053 (96.0%) had blood or CSF samples collected and tested for IgM antibody against JE.Three hundred and eleven cases (29.5%) showed JE antibody positive (JE confirmed case).Among the JE confirmed cases,numbers of those under 15 year of age accounted for 33.7%,43.9%and 88.3%in Baoji,Weinan and Ankang prefectures respectively.The rest were mainly children aged 5-14 years old (53.3%).Toddlers,farmers and children accounted for 85.2%in JE confirmed cases.About half of other VE cases (51.0%) were students of all age.Data an investigation on 398 reported VE cases at discharge,showed that 67.1%of JE confirmed cases recovered while 83.7%of the other VE cases fully recovered.The case fatality rates were 9.2%for JE confirmed cases and 3.1%for other VE cases.578 cases were followed up at 90-days after discharge,69.6%of JE confirmed cases and 90.2%of other VE cases recovered,with case fatality rates were 13.6%and 3.6%for JE confirmed cases and for other VE cases,respectively.The sequelae rates were 10.0%for JE confirmed cases and 4.5%for other VE cases.Conclusion The peak of the VE season was the sameas that of JE.There were 45.6%of reported JE cases with negative JE IgM,suggesting that it is necessary to carry out laboratory testing for clinical diagnosis cases.The fact that high risk population was different at prefectures levels suggested that more attention be paid in JE control and prevention.