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

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

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 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

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 investigate the effects of rhubarb powder on serum complement 3 (C3), complement 4 (C4), and hypersensitive C-reactive protein (hs-CRP) levels in patients with hypertensive intracerebral hemorrhage (HICH) after operation.

METHODSForty inpatients with HICH after operation were recruited from Department of Cerebral Surgery, Affiliated Hospital of Shaanxi College of Traditional Chinese Medicine from July 2009 to March 2010. They were randomly assigned to the treatment group (20 cases) and the control group (20 cases). From the 4th day after surgery, all patients received routine Western medical treatment. The rhubarb powder, 5-10 g dissolving in 40 mL warm water, was administered or nasally fed to those in the treatment group, 2 -3 times daily for 10 successive days. The contents of serum C3, C4, and hs-CRP were detected in the two groups on the 7th day and the 14th day after operation. The serum hs-CRP content was detected using latex particle enhanced immunoturbidimetric assay. The Scandinavia Stroke Scale (SSS) scores were recorded in the two groups.

RESULTSCompared with the same group on the 4th day after operation, the levels of serum C3 and C4 increased on the 7th day after operation, and SSS score increased on the 14th day after operation in the control group (P < 0.05). The contents of C4 and hs-CRP decreased, and the SSS score increased on the 14th day after operation in the treatment group (P < 0.05). Compared with the same group on the 7th day after operation, the contents of C4 and hs-CRP decreased and the SSS score increased on the 14th day after operation in the treatment group (P < 0.05). Compared with the control group at the same time points, the contents of C4 and C3 decreased on the 7th day after operation; the contents of C3, C4, and hs-CRP decreased, and SSS score increased in the treatment group on the 14th day after operation (P < 0.05).

CONCLUSIONThe rhubarb powder could significantly decrease the serum levels of C3, C4, and hs-CRP, and improve the curative effect in patients with HICH after operation.

Adult ; C-Reactive Protein ; metabolism ; Cerebral Hemorrhage ; blood ; Complement C3 ; metabolism ; Complement C4 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Female ; Humans ; Male ; Middle Aged ; Postoperative Period ; Rheum ; chemistry

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

OBJECTIVETo study the effects of lutein on apoptosis and its mechanism.

METHODThe cells of human esophageal carcinoma EC9706 were grown in RPMI medium containing 10% bovine serum and were treated with lutein at 100 microg x mL(-1) concentration. Flow cytometry was employed to investigate the effects of lutein on cell apoptosis of EC9706 cells. Histochemistry was performed to determine apoptosis-related protein expresion.

RESULTFlow cytometry analyses revealed that lutein increased EC9706 cell apoptosis ratio when treated with lutein 100 microg x mL(-1) at 96 h. Lutein decreased the expression of Bcl-2 protein and increased the expression of Bax protein in EC9706 cells.

CONCLUSIONLutein could inhibit mitosis and stimulate apoptosis of EC9706 cells. The apoptotic effect may result from the down-regulation of expression of Bcl-2 and up-regulation expression of Bax.

Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Cell Line, Tumor ; Esophageal Neoplasms ; metabolism ; pathology ; Humans ; Lutein ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; metabolism