Purpose:Cloning IFNγcDNA and constructing pcEgr-IFNγto study its expression intransfected B16 cells induced by X-ray irradiation indifferent doses,and to study the time course of the expression. Methods:IFNγcDNA was cloned by PCR and inserted into pcDNA3.1.CMV promoter of pcDNA3.1 was replaced by Egr-1 promoter to construct pcEgr-IFNγplasmid.The plasmids were transfected into B16 cells.The expression of IFNγof transfected B16 cells with X-ray irradiation indifferent doses and expression time course were detected by ELISA.Results:PCR product was sequenced,there sultindicated the sequence was correct.There combined plasmid was detected by electrophoresis.After X-ray irradiation indifferent doses,IFNγexpression of transfected B16 cells was 77.73 ～ 94.60pg / ml,significantly higher than the control group(P<0.05 ～ P<0.01).Six hours after 2 Gy X-ray irradiation,the expression was the highest(90.00pg / ml),significantly higher than the control group(P<0.001).Conclusion:X-ray caninduce the recombine plasmid expressin B16 cells.The detection of doses and time course provides an experimental basis for invivo study infuture.

Purpose: To further study the effect of E 2 F 1 transcription factor on the transcriptional activation of β promoter, and explain the transcriptional regulation mechanism on MTS 1 gene. Methods:The recombinant plasmid containing 2 or 3 mutant or deleted on E 2 F 1 A, B, C-bound locus sequence on the 0.38 kb fragment cut by SacⅡand SacⅠ of the β promoter was constructed by PCR site-directed mutagenesis and enzymatic cutting and ligating. The recombinant plasmids containing 2 or 3 mutant or deleted on E 2 F 1 A, B, C-bound locus sequence were transfected into Jurkat cells, which were biallelic deletion of MTS 1 gene by transient transfection. Luciferase report gene was used to observe β promoter transcriptional activation. Results: Four new recombinant plasmids containing the mutant with two bound loci of E 2 F 1 A,B,C were obtained separately by PCR, and a recombinant plasmid containing all the three mutant on locus was constructed by enzymatic cutting and ligating, and identified by SacⅠ or NaeⅠenzymatic cutting, and sequencing. The luciferase expression of recombinant plasmid in Jurkat cells decreased, especially the mutant 3 bound locus sequence of E 2 F 1 A, B, C, as compared to the wild-type recombinant plasmid on E 2 F 1-bound locus sequence. Conclusion: These newly-constructed recombinant plasmids can be used to study the function of the transcriptional activation of MTS 1 gene by gene transfection. There is a potential relation between the transcriptional activation of MTS 1 gene β promoter and the transactivation of E 2 F 1 transcription factor.

Purpose: To construct the expression vector with the mutant apolipoprotein CⅡ(apoCⅡ) promoter for studying the transcript activity of the mutant apoCⅡ promoter on - 190 base pair. Methods: The plasmid pGL 3 with normal apoCⅡ promoter was used as the template, and a pair of completely complementary primers with the desired mutation was designed, which make the plasmid amplified and mutated on - 190 base pair of the apoCⅡ promoter using Stratagene's site- directed mutagenesis kit. After being transformed into XL- Blue supercompetent cells, the nicked mutant plasmid was repaired in these cells. Results: The normal apoCⅡ promoter was successfully changed from T to A on the - 190 base pair, the expression vector with the mutant apoCⅡ promoter was constructed. Conclusion: The whole circled plasmid with the desired mutation was obtained by a rapid and efficient method for site- directed mutagenesis, which has an implication for detecting the activity of the mutant apoCⅡ promoter.

Purpose: To construct the pHis-NF and pLacZ-NF plasmids which could be integrated into the yeast genome. Methods: the target DNA sequence of tandem NF-κB copies was synthesized, and the tandem copies were directionally inserted into the MCS of E.coli yeast shuttle pHisi and pLacZi plasmid vectors respectively. The recombinant were confirmed by restriction enzyme digestion, agarose gel, PAGE electropheresis and DNA sequencing. Results: Both PAGE electropheresis and DNA sequence analysis confirmed the inserted oligonucleotides. Conclusion: These two plasmids, pHis-3NF and pLacZ-3NF have been successfully constructed.

Purpose: To investigate the expression of human telomerase reverse transcriptase (hTRT) and C-myc in esophageal epitheliosis and carconogenesis, and their relation to the development of esophageal carcinoma. Methods: Telomerase hTRT and C-myc protein expression in 70 fresh tissue specimen, including esophageal mucosa above the upper surgical margin, carcinoma in situ and mucosa adjacent to tumor, were detected using immunohistochemical method. Results: hTRT and C-myc protein were expressed in proliferating and transformed malignant cells of esophageal epithelium. The expression of C-myc protein showed a similar distribution pattern to that of hTRT. Conclusion: Telomerase hTRT and C-myc protein expressions are closely related to the malignant transformation of esophageal epithelium. The reactivated telomerase and up-regulated C-myc may play a crucial role in the development of esophageal carcinoma.

Purpose: To explore the carcinogenic mechanisms of oral cancer in DMBA-induced hamster. Methods: 0.5 ％ DMBA solution (in mineral oil) was applied topically to the left cheek pouch of male Syrian golden hamsters 3 times per week for 6 weeks, and the animals were observed until the 24 th week. Brdu-labelling index and vascular density were examined by immunostaining in different oral lesions including normal mucosa, hyperplasia, dysplasia, papilloma and squamous cell carcinoma(SCC) . Apoptotic cells were evaluated based on morphological features. Results: Brdu-labeling index and vascular density increased with oral carcinogenesis, and were correlated with oral histopathological grades. Apoptotic index increased from normal mucosa and hyperplasia to dysplasia, papilloma and SCC, but there was no significant difference among dysplasia, papilloma and SCC. Conclusion: Cell proliferation and angiogenesis are the important carcinogeneic mechanisms of oral cancer.

Purpose: To obtain an animal model in which the human lung tumor may successfully be transplanted and survival. Methods: In new born BALB / C mice the immune tolerance was induced by injecting Zheng's plant-protein (ZPP), and then the human lung tumor tissues were transplanted into the mice. Results: 65 ％ (26 / 40) of the transplanted human lung tumor tissues were survival whereas in the control mice the transplanted tumors were totally rejected. Conclusion: ZPP may induce immune tolerance in BALB / C mouse and the transplanted human lung cancer may be survival in the mouse.

Purpose and methods: Using the method of literature metrology to analyse the articles and references in 28 issues of CARCINOGENESIS, TERATUGENESIS AND MUTAGENESIS published during 1995 to 2001. Results: Papers concerning mutagenesis and carcinogenesis decreased in some extent, and those concerning anti-carcinogenesis and anti-teratogenesis slightly increased,and those concerning mutagenesis were still the most in number. The number of the authers per article was averagely 3.84, and most authers were in research institutes and universities; the reginal destribution was extensive for the authers, and prolific authers were still quite few. The average number of references cited per article was 8.01, and most of the references was taken from Chinese or English periodicals. The average half-lifewas averagely 5.62 years for the Chinese literaure, and 1.83 years for the English literatures. Conclusion: Since 1995, the quality of the journal has been improved continuously.

Purpose and methods: The mutagenicity of No.Ⅱdrug was examined using Ames test, CHO-K cell chromosome aberration test and micronucleus test. Results: No.Ⅱ drug in the dose range of 1～5 000 μg / plate did not increase the number of reversion mutation in any of the 4 strains with or without S 9 in Ames test. The frequencies of micronuclear cell(MNCF) in PCE did not increase with dose of 25～125 mg / kg in micronucleus test. In CHO-K cell chromosome aberration test, the result was suspiciously positive because the frequency of chromosome aberration increased to 8 ％ with the dose of 250 μg / ml with S 9. Conclusion: The results of No.Ⅱ drug in Ames test and micronucleus test were negative, and at higher dose in chromosome aberration test the result was suspiciously positive.

Purpose: To study the mutagenicity of Cultured Calculus Bovis. Methods: The studies were conducted with Ames test, micronuclei test and in vitro chromosome aberration test on human lymphocyte. Results: ① The results of Ames test showed no mutagenic effects with the concentration ranged from 1 250 μg / plate to 10 000 μg / plate. ② In micronuclei test, the mice orally received 50, 150, 500 mg / kg respectively per day for 2 days, no mutagenic effects were observed; and no significant reduction was observed on PCE / NCE ratio, compared with that of the negative control group(P>0.05). ③ The in vitro chromosome aberration test on human lymphocyte showed a negative result with the sample concentration ranged from 1 μg / ml to 100 μg / ml. Conclusion: No mutagenicity was found with Cultured Calculus Bovis in this experimentation.

Purpose: To evaluate the cytogenetic effects of trichloroethylene(TCE) on the workers, and to determine the dose-response and time-response correlations among the exposure level and duration. Methods:TCE concentration in the work place and TCA in urine of the workers exposed to TCE were determined using gas chromatography and pyridine spectrophotometry, respectively. Conventional micronucleus(MN), cytokinesis-block micronucleus(CB-MN), sister-chromatid exchanges(SCE), and single cell gel electrophoresis (SCGE) from 141 workers exposed to TCE and 39 controls were carried out to determine chromosomal and DNA damage. Results: In the TCE-exposed group(the average concentration of TCE in work place was 90.4 mg / m 3, the average level of urine TCA of the workers exposed to TCE was 61.79 mg / L), the frequencies of MN, CB-MN, SCE and the percentage of lymphocytes with comet-like tail in peripheral blood lymphocytes(PBLs) were 1.66 ‰, 2.73 ‰, 4.33 and 7.48 ％, respectively, and were higher than those in the control groups(1.13 ‰, 1.66 ‰, 2.95 and 3.74 ％, respectively, P<0.05 or P<0.01). Except for SCE, there were positive correlations between the percentage of MN，CB-MN, the percentage of lymphocytes with comet-like tail in PBLs and the exposing time(r=0.222, 0.246, 0.320; P<0.05 or P<0.01). The positive correlations were also evidant between the percentage of MN，CB-MN, SCE and the percentage of lymphocytes with comet-like tail in PBLs and the the average level of urine TCA of the workers exposed to TCE (r=0.294, 0.260, 0.229, 0.268; P<0.05 or P<0.01). Conclusions: TCE is genotoxic, and long term exposure to the high dose of TCE may induce chromosome breakage and DAN damage.

Purpose: To study the concentration of total suspended particulates (TSP) and the mutagenicity of the organic extracts in heating and unheating seasons in Xi'an City. Methods: Based on the distribution of the city functional district, four surveillance spots (industry zone, mixed zone, heavy traffic zone and control zone)were chosen by the method of grid. The concentration of TSP and mutagenicity of the organic extracts were investigated in 96 TSP samples obtained from two seasons by means of increasing weight and Ames test, respectively. Results: In heating and unheating seasons, the TSP concentration was 0.586 5 mg / m 3 and 0.353 5 mg / m 3, respectively. The difference was highly significant(P<0.05), and the TPS concentrations in two seasons were also significantly higher than the control group(P<0.05). The positive mutagenicity of organic extracts was tested in all functional sampling spots, and the positive rate in heating period was significantly higher than unheating season(P<0.05), but there was no difference among the same season samples (P>0.05). Conclusion: There was an obvious relationship between the TSP concentration and the season, and the TSP level was the highest in the heating season. The coal consumption was probably one of the main reasons of enhancing the mutagenicity of TSP in Xi'an City.

Purpose: To detect the effects of cell proliferation inhibition and chromosome aberrations of Kuaishaling and Deltamethrin on mouse bone marrow. Methods:Two insectisides were administrated to mice at three different doses of 1 / 4, 1 / 2, 1×LD 50 (single doses of 1 / 20, 1 / 10 and 1 / 5×LD 50, the LD 50 of Kuaishaling and Deltamethrin were 72.8 mg / kg and 26 mg / kg) by gavage once a day for five days respectively, single gavaged volume was 20 ml / kg; the cell proliferation indices, the rates of chromosome structural aberrations and the rates of the cells with chromosome aberrations were detected by the methods of cytogenetics. Results: The cell proliferation indices of mouse bone marrow cells decreased significantly at all the three tested doses of these two insecticides as compared with the negative control group, the cell proliferation indices induced by Kuaishaling and Deltamethrin were 3.38±0.42～3.40±1.16 (P<0.000 01) and 5.12±0.47～5.97±0.62 (P<0.001～P<0.000 1), respectively; both the rates of chromosomal structural aberrations and the rates of the cells with chromosomal aberrations increased significantly at the high dose of Kuaishaling and the three tested doses of Deltamethrin, the rates of chromosomal structural aberrations and the rates of the cells with chromosomal aberrations induced by the high dose of Kuaishaling were 8.87±1.65(P<0.001) and 7.21±2.10(P<0.01), respectively, those induced by the three tested doses of Deltamethrin were 11.74±2.81～23.42±2.17(P<0.001～P<0.000 1) and 9.36±1.52～17.33±3.68(P<0.001～P<0.0001), respectively; the chromosomal aberration types caused by Deltamethrin were more complex than by Kuaishaling. Conclusions: Kuaishaling and Deltamethrin can not only inhibit cell proliferation, but also cause chromosome damages. Moreover, using LD 50 as the evaluating criterion, the effect of cell proliferation inhibition caused by Kuaishaling is stronger, whereas the effect of chromosome aberrations caused by Deltamethrin is stronger.