Objectives To study the influence of Staphylococcus epidermidis (SE) on the neonatal mice of different ages. Methods A total of 60 neonatal mice including postnatal day 1(PND1) and postnatal day 3(PND3) were divided into SE group, normal saline (NS) group and control group, with 20 mice each. Mice in SE group were intravenously injected with 50μl SE (108/ml). Mice in NS group were given 50μl NS and mice in control group was not intervened. On postnatal day 14, the brain, liver and spleen obtained from mice were weighted. Serial sections of paraffin-embedded brain tissue were used for the detec-tion of microtubule associated protein-2 (MAP-2) and myelin basic protein (MBP) by immumohistochemical staining, and then the areas and volumes of grey and white matter were calculated. Result The mortality of PND1 mice in SE and NS group was 60.0%and 40.0%, respectively, and there was no difference between two groups (P>0.05). The mortality of PND3 mice in SE and NS group was 10.0%and 0.0%, respectively, and there was no difference between two groups (P>0.05). There were no dif-ferences in body weight, body weight gain, spleen and liver weights and organ coefficient between PND1 and PND3 mice (P>0.05). In PND1 mice, the areas and volumes of grey and white matter were significantly smaller in SE group than those in NS group (P<0.05). However, in PND3 mice, there was no differences in areas and volumes of grey and white matter between SE and NS group (P>0.05). Conclusions SE infection can result in brain injury in PND1 mice, but has no effect on brain tissues of PND3 mice.

OBJECTIVE:To determinate the serum concentration of methotrexate by HPLC. METHODS:The samples were separated on a Waters C18 column at a column temperature of 30 ℃. The mobile phase consisted of acetonitrile-phosphate buffer(pH 7.2,12∶88) at a flow rate of 1.0 mL?min-1. The detection wavelength was set at 303 nm. RESULTS:The linear range of methotrexate was 0.5～80 ?g?mL-1(r=0.999 4). The methodological recovery rates were all above 90%; the intraday RSD was 3.03 %～3.52 % and the inter-day RSD was 2.57%～4.05%. CONCLUSION:The method is proved to be simple,rapid,accurate and sensitive,and it is suitable for the determination of serum concentration and pharmacokinetic study of methotrexate.

Objective To establish a RP-HPLC method to determine the content of geniposide in Xiaoyan Tuire Patch. Method The column of Agilent ZORBAX SB-C18 (4.6 mm?250 mm 5 ?m) was used. The mobile phase was composed of water-acetonitrile-phosphoric acid (86∶14∶0.01). The flow rate was 1 mL/min, with UV detection at 238 nm, and the temperature was 30 ℃. Results The linear range was 0.07～0.70 ?g (r =0.99997). The average recovery was 98.60% and the RSD was 1.96%. Conclusion The method is simple, sensitive and accurate, and can be used for the determination of Xiaoyan Tuire Patch.

Objective To establish a RP-HPLC method to determine the content of ephedrine?HCl in Xiaoyan Zhike Plaster. Method The sample was prepared according to 2005 edition of Chinese Pharmacopocia, the column of Inertsil-3 ODS (4.6 mm?250 mm, 5 ?m) was used. The mobile phase was composed of methanol-0.1% of phosphoric acid (5∶95). The flow rate was 1 mL/min, with UV detection at 207 nm. Results The linear range was 0.041～0.41 ?g (r=0.999 8). The lowest limit of detection was 0.025 6 ?g. The average recovery and the precision was 99.55% and 2.58%. Conclusion The method is simple, sensitive and accurate, and can be used for the quality control of Xiaoyan Zhike Plaster.

ObjectivesTo study the mechanism of brain damage caused byStaphylococcus epidermidis (SE) in mice. Methods A total of 80 neonatal mice of postnatal day 1 (PND1) were divided into SE group (48 mice), normal saline (NS) group (16 mice) and control group (16 mice). Mice in SE group were intravenously injected with 50 μl SE (108/ml). Mice in NS group were given 50 μl NS. Mice in control group were not intervened. At different time points after SE injection (6 h, 24 h, 72 h, 5 d, 7 d), the CFU of brain, blood, and spleen were calculated. Serial sections of parafifn-embedded brain tissue were used for detection of ionized calcium-binding adaptor moleculor1 (Iba-1) by immunohistochemical staining. The positive cells were calculated. ELISA was used to measure the levels of tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-5 (IL-5), interleukin-6 (IL-6) of brain at 6 h and 24 h after SE injection.Results There was no SE in brain in different time points. The CFU was at the highest level at 6 h and then decreased after 24 h in blood and spleen. The Iba-1 positive cells in SE group were signiifcantly increased compared to NS group and control group at 24 h and 72 h (P<0.05). There was no difference of Iba-1 positive cells be-tween 24 h and 72 h after SE injection (P>0.05). The levels of TNF-α, IL-1β, IL-5, and IL-6 were signiifcantly higher in SE group than those in NS and control at 6 h and 24 h (P<0.05). The levels of TNF-α, IL-1β, IL-5, and IL-6 were signiifcantly lower in SE group at 24 h than those in SE group at 6 h (P<0.01).Conclusions It is suggested that cytokines produced by microglias may be the mediators of SE-caused brain damage.

Objective To compare the gene expression difference between 0.1 and 5 Gy X-ray irradiated cells,and to explore its possible mechanism.Methods A cDNA microarray corresponding to 45033 human genes was used to analyze the transcriptional profiles of normal human lymphoblastoid AHH-1 cells at 4 h after 0.1 or 5 Gy irradiation.The genes with a fold change ≥ 2.0 were identified as the differentially expressed genes.real-lime PCR and Western blot were used to confirm the expression of PERP.Results The microarray assay showed that there were 760 up-regulated genes and 1222 down-regulated genes in the cells at 0.1 Gy,while there were 744 genes down-regulated and 457 genes up-regulated in the cells at 5 Gy.In addition,55 genes were commonly up-regulated and 339 genes commonly down-regulated at 0.1 and 5 Gy.The predominant biological processes of the differential genes responding to low-dose radiation include cell-cell signaling transduction and DNA damage response,and the altered genes after 5 Gy irradiation were related to cell proliferation,differentiation,and apoptosis.Moreover,the expression of PERP gene was down regulated,which was consistent with the data of microarrey assay.Conclusions The quantitative and qualitative differences in the gene expressions may contribute to the diversed biological effects induced by low or high doses of ionizina radiation.

Objective To observe the radiosensitivity by targeting HIF-lα in human lung cancer and the effects on tumor growth in nude mice.Methods Radiosensitivity of A549 and A549/HIF-1α ( － ) cells were tested by clonogenic forming assay.A549/HIF-1 α( － ) cells and A549 cells were injected into the male BALB/C nude mice.Tumor growth was observed.The expression of HIF-1α and microvessel density were detected by immunohistochemistry method.Results SERs of HIF-1α gene silencing were 1.03 in normoxia and 1.65 in hypoxia.The sizes of tumor xenografts derived from A549/HIF-1α( － ) cells were significantly reduced compared to those of the xenografts derived from A549 cells.HIF-1 α protein staining result showed a dramatic decrease in tumors from A549/HIF-1α ( － ) mice.The microvessel densities (MVD) were 19.83 ± 4.09 in A549 group and 11.61 ±3.04 in A549/HIF-lα (-)group(F=15.57,P ＜0.05 ).Conclusions Hypoxia-induced radio-resistance in lung cancer A549 cells could be reversed by silencing the HIF-1α.It also retards the growth of tumor xenografts,decreases HIF-1α expression and reduces the vascularity.

Objective To investigate the chromosome damage in peripheral lymphocytes of underground gold miners.Methods Conventional method and cytokinesis-block micronuclens assay were used to analyze frequency of chromosome aberrations and micronucleus in peripheral lymphocytes in 58 gold miners,respectively.Results Frequencies of chromosome-type aberrations,ehromatid-type aberrations and total aberrations were higher in the miners than those in the control group(0.72%,0.41%,1.16% vs 0.14%,0.18%,0.33,X2=44.322,9.501,50.476,P＜0.01).Both micronucleated cell rate and micronucleus rate were higher in the miners group than those in the control group(10.8‰ and 11.6‰ vs 8.7‰ and 9.0‰,X2=8.672,12.546,P＜0.01).Frequencies of chromosomal aberrations and micronucleus proportionally increased with underground working years.Compared with those miners who had worked underground 6 years or shorter,both frequencies were statistically higher among the miners who had worked underground for more than 21 years(P＜0.05).No difference was found among other groups of working years(P＞0.05).Compared with the control group,both frequencies increased in the miner group,and the differences were statistically significant(X2=2.395,P＜0.05 for chromosomal aberrations and X2=2.319,P＜0.05,respecfvely).The common types of chromosome aberrations were acentrie fragments,while chromatid break and dicenrics were subordinate.Conclusions Chromosomal damages were observed in the gold workers who exposed high radon in the underground mining.

objective To study the TCR gene mutation in peripheral blood lymphocytes induced by X-ray exposure using cultured lymphocytes cloning method.Methods Freshly isolated peripheral lymphocytes from healthy aduh donors were irradiated with X-ray in doses ranging from 0 to 8 Gy and cultured with interleukin2 and phytohemagglutinin for 7 days.The mutant frequencies of TCR gene(TCR MF)were detected by flow cytonletry and the dose response curves were fitted.Results TCR MF increased with the dose going up.An aquadratic polynomial dose response model was fitted.Conclusions TCR gene mutation could which serve as a potential biological dosimeter.It might be applied for the estimation of biological dose in emergency exposure.