OBJECTIVE:To establish an HPLC method for determination of ganciclovir in serum of dogs and to study pharmacokinetics and relative bioavailability of Ganciclovir dispersible tablets.METHODS:The determination was performed on Dikma DiamonsilTM C18 column.The mobile phase consisted of 0.015 mol?mL-1 monobasic potassium phosphate buffer solution (pH 2.50,containing 0.25% acetonitrile) with flow rate of 1.75 mL?min-1 at detection wavelength of 254 nm.The column temperature was set at 40 ℃.In a randomized cross-over study,a single dose of dispersible tablets and the capsule were given to 6 dogs.An HPLC method was used to determine plasma concentration of ganciclovir in dogs and the pharmacokinetic data were treated by DASver1.0 software.RESULTS:The linear range of ganciclovir were 0.050 25～100.5 ?g?mL-1;the methodological recovery was larger than 90% (RSD

Objective To explore the developmental toxicity of aluminum sulfate and its mechanism. Methods 8.5-day-old embryos of Kunming mice were explanted and cultured in a whole embryo culture system with Al 3+ concentrations of 0.6, 0.9, 1.2, 3.0, 6.0, 9.0 ?g/ml for 48 h. Each viable embryo was evaluated using Maele-Fabry scoring system, and visceral yolk sac diameter, crown-rump and head length, and embryo dry weight were measured, as well as GSH activity in embryonic tissue by using 5,5-dithion-bis-2-nitrobenzoic acid (DTNB), and membrane lipid fluidity of visceral yolk sac cell by DPH fluorescence polarization technique. Results Al 2(SO 4)3 at Al 3+ concentration of 3 ?g/ml resulted in significant inhibition of development of embryos and differentiation of organs, and increasing prevalance rate of abnormal embryos including open neural tube, small head abnormality and deficit in flexion. At Al 3+ concentration of 6.0 ?g/ml, the activity of GSH and the membrane lipid fluidity of visceral yolk sac decreased significantly. In a certain degree, the dose-effect(response) relationship were observed in the above hazardous effects induced by Al 2(SO 4)3. Conclusion Al 2(SO 4)3 presented potential teratagenicity and embryotoxicity, which might be associated with the decreases of the membrane lipid fluidity of visceral yolk sac and the activity of GSH both induced by Al 2(SO 4)3.

Objective　To explore the effects of chemical reaction of aluminum salt in water solution on developmental toxicity.Methods　Inhibiting actions on embryo growth and development,and organ morphogenetic differentiation in rats induced by newly prepared and 11.5-month stored aluminum sulfate solution were observed and compared using whole embryo culture method in rats.Results　Both of the two observed solutions showed a certain embryo toxicity and teratogenicity.The toxicity of stored solution decreased significantly compared with that of newly prepared solution.At the same concentration of aluminum,the total Brown's morphogenetic score reflecting the every index of embryo growth and development and organ morphogenetic differentiation,the incidence rates of terata and the number of dead embryos were significant lower in rats exposed to stored solution compared with those exposed to newly prepared solution,especially the morbidity of embryos.Conclusion　The complexation reaction between aluminum ions (Al3+) and water molecules in stored aluminum sulfate solution resulted in the changes of existing state of Al3+ and its decreasing developmental toxicity to rats.

Objective To explore the effects of chemical reaction of aluminum salt in water solution on developmental toxicity Methods Inhibiting actions on embryo growth and development,and organ morphogenetic differentiation in rats induced by newly prepared and 11 5 month stored aluminum sulfate solution were observed and compared using whole embryo culture method in rats Results Both of the two observed solutions showed a certain embryo toxicity and teratogenicity The toxicity of stored solution decreased significantly compared with that of newly prepared solution At the same concentration of aluminum,the total Brown's morphogenetic score reflecting the every index of embryo growth and development and organ morphogenetic differentiation,the incidence rates of terata and the number of dead embryos were significant lower in rats exposed to stored solution compared with those exposed to newly prepared solution,especially the morbidity of embryos Conclusion The complexation reaction between aluminum ions (Al 3+ ) and water molecules in stored aluminum sulfate solution resulted in the changes of existing state of Al 3+ and its decreasing developmental toxicity to rats

Objective: This study was designed to investigate the molecular mechanisms of proliferation and apoptosis by genistein and zearalenone through regulation of mRNA and protein expression of PCNA, bcl-2 and bax in breast cancer MCF-7 cells. Methods: The cells were maintained in DMEM medium with 10% fetal bovine serum. Five days before the beginning of experiments, the cells were seeded in phenol red-free DMEM medium containing 5% charcoal dextran–treated FBS. The cells were harvested and seeded in 6-well culture plates or in 75 ml flacks. After various concentrations of genistein and zearalenone treatments for 72 h, the cells were harvested and mRNA and protein expression of proliferation cell nuclear antigen(PCNA), bcl-2 and bax were detected by reverse transcription-polymerase chain reaction and immunohistochemistry, respectively. Results: At the concentration of 75 ?mol/L, GS could significantly down-regulate bcl-2 and PCNA mRNA expression and up-regulate bax mRNA expression, and zearalenone indicated an opposite result. These results were further confirmed by following immunohistochemistry. Conclusion:PCNA, bcl-2 and bax pathway might be involved in cell proliferation and apoptosis events regulated by dietary estrogens genistein and zearalenone in breast cancer MCF-7 cells.

Objective　To explore the potential hazards of organic pollutants in chlorinated drinking water on human reproduction.Methods　The reproductive toxicity of the organic pollutants extracted by solid phase extraction technique from chlorinated drinking water in a city,was determined by the co-culture of sertoli cells and spermatogenic cells.Results　No significant variation of the rate of detached spermatogenic cells was noticed compared with the control rats.The organic extracts stimulated the secretion of lactate from sertoli cells of testis in rats.Conclusion　The organic extracts of chlorinated drinking water revealed potential reproductive toxicity.

Objective　To explore the mechanism of male reproductive toxicity of bisphenol-A.Methods　The morphological characteristics of seminiferous tubule,vimentin filaments and p53 gene expression in sertoli's cells of adult SD rats orally exposed to 0.5% bisphenol-A were observed and analyzed by histo-chemical and immuno-histochemical methods.Results　After 2-week-exposure to 0.50% bisphenol-A,the disattachment between sertoli's cell and spermatogonia,spermatogonia arranged in disorder and displacement of spermatogonia away from the basement membrance of seminiferous tubules as well as the flocculated chromatins of nuclei in sertoli's cells and spermatogonia were observed.Fourfold increase of p53 expression in nuclei of spermatogonia and leydig's cells and the collaps of vimentin filaments in sertoli's cells were also found.Conclusion　The results suggested that the disattachment between sertoli's cells and spermatogonia,might be associated with the collaps of vimentin filaments in nuclei of sertoli's cells and the increase of p53 expres sion in nuclei of sertoli's cells and spermatogonia,which might be one of the important mechanisms of reproductive toxicity of bisphenol-A.The increase of p53 expression in nuclei of leydig's cells might predict the potential anti-androgenicity of bisphenol-A

Objective To study the toxic effect of flutamide (Flu) on testis with DNA chip. Methods Flu was injected subcutaneously at doses of 6.25 mg?kg-1 ?d-1 to 25 F0 rats from gestation day (GD) 12 to 17, and the 25 rats of control group received same doses of normal saline. All 50 pregnant SD rats were sacrificed on GD 20.The cDNA were extracted respectively from fetal testis, then reversely transcribed to cDNA and labeled with cy5 and cy3 fluorescence. Subsequently, cDNA probes were hybridized to the Mouse40S cDNA microarray and fluorescence signals were analyzed. Testosterone level was determined by enzyme-linked immunosorbent assay (ELISA). Results Compared with control,a total of 31 identified gene was found to be expressed differently, including 14 down-regulated and 17 up-regulated. Among them, 5 down-regulated and 10 up-regulated genes were unknown in Genbank. ELISA indicated that testosterone levels were decreased in Flu toxic group. Conclusion Flu treatment to F0 pregnant rats can damage apparently to the reproductive development of embryonic period male SD rats. The obtained differential genes may provide reference for the molecular mechanism of reproductive development.

Objective To establish a method to investigate micronuclei (MN) and gene mutation at the heterozygous thymidine kinase (tk) locus induced by environmental mutagens in TK6 human lymphoblastiod cells. Methods TK6 cells were used to detect cytotoxic response, MN and mutation frequency at tk locus induced by cyclophosphomide (CP) after treatment with S9 mixture for 4 h. Results Exposure to CP for 4 h decreased relative survival (RS), induced both MN and TK mutation in a concetration-dependent manner. The maximum induction of MN and TK mutations were 8.8 and 15.7 times compared with those of control. Two distinct phenotypic colonies of TK mutants were generated, namely tk-NG and tk-SG mutant colonies but mainly the latter. Conclusion CP induced both MN and TK mutation in TK6 cells. TK6 cells can be used as an in vitro assay system to assess cytogenetic damage and gene mutation at tk locus of environmental chemicals.

Objective To investigate the effects of p53 protein and mRNA expression in rat liver tumor promotion by phenobarbital(PB). Methods Male Wistar rats were randomly divided into 6 groups,i. e. higher dose group,middle dose group,lower dose group,tumor-initiating control group,tumor-promoting group and normal control group. The rat liver tumor DEN-initiating-PB-promoting model was established among higher dose group,middle dose group,lower dose group and tumor-initiating control group. The rats in higher dose group,middle dose group and lower dose group were fed with feed containing 500,100,50 mg/kg PB respectively. The rats in liver-tumor promoting control group were only fed with normal feed. The rats in tumor-promoting group weren't initiated by DEN,were only fed with feed containing 500 mg/kg PB. The rats in normal control groups weren't treated by any factors. At the 1st,5th,10th,15th,20th,30th week of the exposure to PB,the expression of p53 protein and p53 mRNA of the rats in every group were determined by immunohistochemistry and in situ hybridization respectively. Results The expression of the mutant type p53(mtp53) protein was found in liver tumor-initiated rats which revealed precancerous lesion. The expression of p53 protein of rats increased in higher and middle dose groups,and showed higher levels in lower dose group and liver tumor-initiating control group compared with those of normal control group which didn't variate significantly with the prolongation of period of exposure to PB. The expression of wild type p53 (wtp53) mRNA showed lower levels in rats of normal control group and liver tumor-promoting group,showed higher levels in higher dose group,middle dose group,lower dose group and liver tumor-initiating control group compared with those in normal control group. The expression of wtp53 mRNA decreased in higher dose group and middle dose group,increased a little in lower dose group and liver-tumor-initiating with the prolongation of period of exposure to PB. Conclusion During the promoting stage of rat liver tumorigenesis tumor promotor PB might reduce the expression of wtp53 and induce mtp53 expression,which affected the cell cycle arrest and apoptosis,and might favor clonal expansion of preneoplastic hepatocytes,which promoted the formation of liver tumor.