Purpose : The purpose of the present study was to investigate the regional dist ribution of CYP1A1 mRNA in rat brain and the effect of Deltamethrin on CYP1A1 gene expression. Methods : By the methods of RT2PCR and dot blot analysis. Results : By the methods of RT2PCR and dot blot , it was revealed that the regional dist ribution of CYP1A1 mRNA varied in different brain ; Deltamethrin inhibited the expression of CYP1A1 mRNA , especially in cerebral cortex , under the t reatment of Deltamethrin with the dose of 12. 5mg.kg - 1 . d - 1 ip. for five days. Conclusion : These result s demonst rated that Deltamethrin markedly inhibited CYP1A1 gene expression.

Purpose : To study the morphological method to distinguish aneugens f rom clastogens. Methods : According to the morphological criteria micronuclei were classified and quantitatively analyzed induced by six reference mutagens (aneugens : colchicine , vincristin ; clastogens : cyclophosphamide , mitomycin C , ethyl methane sulfonate , gamma - ray) . Results : In comparing with the result s by clastogens , the f requency of circle micronuclei by aneugens was significantly increased( P = 0. 003) , ring micronuclei remarkably decreased ( P < 0. 0001) ,and crescent micronuclei did not change evidently ( P = 0. 07) . The 95 % confidence intervals of the mean micronucleus f requencies in class between the two types of mutagens were different very much , of which circle and ring frequences were completely separate. A discriminating function was acquired f rom the paper data. Conclusion : The f requencies of circle , ring and crescent micronuclei can be as a means to distinguish aneugens and clastogens.

To study the pathological change Of organs of mice immunitied byⅫ Ag DNA vaccine．Methods： HBsAg vaccine was i~ected into muscles of mice Anti—HBsAg antibody w analyzed by ELISA．After 12 weeks，the immunitied mi ce were killed and those organs were analyzed by pathological methods． Results：Anti 一Ⅻ Ag antibody in mice was positive after one wek．Spleens of mice were 4 folds larger than contro1． Kindeys and 1Nets were severe iniured．Conclusion：sAg vacine can induce mice to create antibody，lasting 12 weeks and more．But，pathology ch~rlge of organs indicated that the production of vaccine or related react_ may give rise tO the damage of the organs of mice ．This result make~to study the．safety of H&Ag vaccine further

Purpose and Methods：Utilizing a cell transformed model composed of a human bronchial epithelial cell Iine(BEAS-2B)，BEA&2B cell transformed hy eyelophosphamide(BEAS—CP)and thiotepa(BEAS—T)，cytogenetie alteration a~soeiated with neoplastic trans{ormation of human bronchial epithelial cells was observed Restilts：BEAS一2B cells have near diploid karyotype and genotypically stable Three chromo~mal markers present BEAS-CP cell was mainly diploid with a variable proportion of polyploid celN．Chromosome 14 has lost one of two copies of chromosome and chromo~mal mark M4 has formed Those changes might be lhe original alteration induced by alkylating effect of cyclophosphamide and as the primary alteration involved in transformed initiation，promotion and progression BEAS—T cell mainly consists of po lyploid cells．．~ome cells loss of monosomy of chromosome 8 and 21．BEAS-T∞ft agar selected cells(BEAS—ST)were all polyploid cells and characterized by a high frequency of unstable aberrationsffrom 3％ of BEAS—T 25p up to 34％ of BEAS—ST)．Another speci~ alteration for BEAS-ST is two pairs of the largeness tricentric chromosome．Conclusion：These aberralions have a strong re／atioship with cel malignant transformation and the transformed cells might have the tumorgenesis ability in nude mouse．

Results：This paper reports that Ge一132 possessed the remarkable resistance effeets on AFB．reducing Superoxide Dismutase(SOD)activity in vivo during AFBt—induced hepatocarcinogenesis for short term modal experiments The SOD activity can be affected by the time and the dosage of Ge一132 intaken．Conclusion：The results indicated that antioxidative ability of Ge一132 is relate to im anticareiogenicity．Ge一132 can be used ∞ a safe and efective chemopreventlon agent．

Pcrpo~ ：In order to detect genotoxieity of the different samples from water supply and drainage in Shanghai．Methods：vicia—miemnueleus test was used in this study．Results：It showed that besides tap watP2"and pond water in one Park．there exited some different levels of pollution in the rain water，upriver water，one river，and one po llution plant．The water po llution in the infall of pollution plant was the heaviest．Conelnsion：Vieia—mieronucleus test was sensitive．simple，economic．So it was a very valuable short—term bloloical test for screen environmental mutagen．

purpose：To observe the expression of costimuLatory mo|ecule B7 1 in tumor cell 1ines and establish the cel1 modelto studvthe function 0{B7．1 n vitro．M ethods：B7．1 molecule Of tumor cd11ines was studied by SABC immunocytochemistry．staining Results：An cell liaes(7721，BLS211．GRC1，MGC)except BLZ211 and A375 expre．~sed B7．1．Conclusion：M o．st of the tumor cd1 fines studied in this experiment have no ddideacy in expre~slon of B7 1 protein The B7．1 poMtive eell 1ines can he used as models to study 137．1 function in vitro

Purpose and Methods：This paper reported the effect of the M ylahris phalerata Pallas on TA97， TA98，TAIO0，TA102’S reverse mutation．micronucleus test of polychromatophilic erythrocyte(PCE)，sister chromatid exchange(SEE)of the mouse nit,KrDDW’S cells．Results：Mylabris phalerata Pallas decocted fluid has no direct mutagenic effect on TA97，TA98，TAIO0 and TA102．The decocted fluid of high(82．84rog／kg)and middle dc~ge(49．70rag／kg)gmups cal increase the mieronucleus rate．The deeocted fluid of high(1OOmg／kg)and mMdle dosage(50mglkg)groups can increase tbe frequencies of SCE：Conc|~ion：These re．subs indi—cared that the decocted fluid of Mylahris phalerata Pallas has some routagenicity，and the mutagenicity effect of the Mylabrls Phalerata Pallas is first be reported．

Purpose and Methods：The mutagenielty of Cyclophosphamide(CP)and Ifosfamide(IFO)was stud— led using An1es test and SOS chromotest．Results·In Ames test both CP and IFO were found negative results on strain TA100 without metabolic activation system (S9一mix)but positive in the presence of S9一mix，showing a significant dose— dfect relationship．The mutageniclty induced by both drugs were of different degree The amount of rev~'se mutation induced by IFO was Iess than that of CP at the same dose Ieve[．At 1 0O()ug／plate dose 1evel-the amount of reverse mutation induced by CP and IF0 was twelve times and five times m0re than that of the control respectively．However，negative results were observed on strain TA97、TA98 and TA102 (without or with s9 mix)for both drugs But SOS chromotest indicated that neither CP and IFO had inducti。n SOS repair system in E Coli strain PQ35、PQ37 with or without 89 mix．Conchmion：We c0nduded that the mutagenicity of CP and IF0 was resulted from base substitution induced by themselves，and CP showed stf0ngef mutagenicity than IFO． Thus protection for workers producing or operating CP and IFO against their genotoxicity was necessary．