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摘要: Objectives. In order to identify the relationship between telomerase and the biological effect of radiation injury,and investigate the role of human telomerase catalytic subunit gene (hEST2) reverse transcriptase(RT) segment in the expression of telomerase activity. Methods. Tumor HeLa cells, KB cells and A431 cells were employed to measure the change in telomerase activity after 60Co ray irradiation at RNA level and protein level. Quantitative PCR and Northern blotting were used to determine the expression of hEST2 RT segment that encodes seven motifs of the human telomeres, a PCR based telomeric repeat amplification protocol (TRAP)was used to assay telomerase activity after exposure to radiation. Results. Both of telomerase activity and the expression hEST2 RT segment were decreased with increasing dosage of radiation. In addition, testing the expression of motifs domain is similar to the measurement of telomerase activity. Conclusion. The detection of the hEST2 RT segment by Northern blotting and quantitative PCR are new methods for testing telomerase activity. Furthermore, radiation can cause a dose dependent decrease in telomerase activity. The effect of radiation on telomerase is one possible reason for the death of cancer cells after irradiation.

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  • 作者:何小东;陶蔚;郑朝纪;张振寰

    Objective. To improve the localized diagn osis of insidious recurrent small intestinal hemorrhage.Methods. This retrospective analysis include 64 cases of such diseases, which were admitted from 1988 to 1998 to our hospital.Result. Ultrasonography, CT, small bowel pneumobariumgraphy, diluted barium enema, isotopic examination,DSA and intraoperative small-bowel endoscopy were used for diagnosis of hemorrhagic site, and 37 cases got a definite location before operation, while 10 cases were confirmed the diagnosis during the operation. Forty-seven cases were treated surgically, while the other 17 cases had non-surgical treatment. Of the 47 cases,39 cases underwent partual enterectomy, 5 cases had suture and ligature of vascular deformity, 2 cases had Whipple' s operation, and one patient had ectomy of the end of ileum and right colon.Conclusion. DSA, Isotopic examination and intraoperative enteroscopy are of considerable importance for the location judgement of recurrent small intestinal hemorrhage.

  • Objective. To investigate the expression of telomerase gene hTRT mRNA in HeLa cells and to obtain hTRT pro-tein for futher study. Methods. The gene for encoding hTRT catalytic domain was cloned based on RT-PCR amplification from HeLa cells and sequenced. The cloned hTRTcDNA was in-frame inserted into His-tag fusion expression vector pEK318. The His-tag hTRT fusion proteins were purified by Ni-NTA chromatography and stained by westerm blotting. Results. An approximately 620bp fragment was generated and cloned into pBluescript SK + between Sail and BamHI sites. DNA sequencing showed the isolated fragment was consistem to those reported. SDS-PAGE present that a 17kDa protein was expressed stably in E. coli JM109 harboring pEKTRTM4 containing 6 × His-tag and hTRT 150aa, and the expression level of the protein was about 26% of the total bacterial proteins, while the expression of pEKTRT containing 6 × His-tag and hTRT 243aa was only detectable as 27 kDa band in western blotting. Both of fu-sion proteins were purified by Ni-NTA chromatography and showed single band( > 95% purifity) in Coomassie Bril-liant staining. Westem-blotting confirmed that two proteins could be recognized by the Ni-NTA AP conjugate. Conclusions. The hTRT catalytic domain was highly conserved. The expressed hTRT protein contained recogniz-able His-tag, telomerase-specific and strong antigenic epitops, which may be convenient for further investigation.

  • Objective. In a model of rat cardiac hypertrophy, the changes in the distribution of ET-1 receptors in two subcellular fractions, the sarcolemma and the light vesicles during myocardial hypertrophy were studied. Methods. Cardiac hypertrophy was produced by placing a constricting clip around the suprarenal abdominal aorta of rats, and ET-1 receptor was assayed with radioactive analysis method. Results. It was found that plasma and ventricular ET-1 levels increased significantly on week 2 and week 4 of pressure overload. ET-1 binding studies showed that during myocardial hypertrophy, the maximum binding capacity (Bmax) was increased by 41% (P<0.01) and 65% (P< 0.01) in sarcolemma in H-2 week and H-4 week groups, but was decreased by 24% (P< 0.01) and 21% (P< 0.01) in light vesicles. The sum of Bmax of sarcolemmal and light vesicle fractions was increased by 33% (P< 0.01) and 57% (P< 0.01) in group H-2 week and H-4 week, respectively. ? Conclusion. ET-1 receptors in rat heart were externalized from light vesicles to sarcolemma, which may contribute to the development of myocardial hypertrophy.

  • 作者:贲勇;于洪泉;王振杰;苗齐;任华;张志庸;李泽坚

    Objective. The effectiveness of surgical resection of adenosquamous carcinoma of the lung remains poorly defined because of the histology' s relatively low frequency, the failure in most published series to separate adenosquamous carcinoma from the other variants of non-small cell lung carcinoma. To define the effectiveness of surgical treatment of adenosquamous carcinoma, we have retrospectively reviewed our hospital experience over a 12-year period. Methods. Retrospectively reviewed 22 cases of adenosquamous carcinoma who were surgically treated, except one patient,in the PUMCH from Jan. 1985 to Aug. 1997.This series constitutes the 1.9% of a total of 1 245 patients with all types of surgical treatment for the primary lung cancer during the same time. Results. The adenosquanous carcinoma was mostly presented in the old patients with a mean age of 60 years and mostly located in the peripheral of lung(n= 20).The overall 5-year survival was 23%.Those with stage Ⅰ tumors survival was only 18%(n= 13), stage Ⅱ 5%. The survival in stage Ⅲ tumors was not longer than 25 months and in stage Ⅳ survival was not longer than 12 months.Conclusion. Our results suggest that adenosquamous carcinoma of lung was a virulent tumor, which exhibited highly aggressive biological behavior with early lymph nodes metastasis(46% ) and its prognosis was worse than that of both squamous cell carcinoma and adenocarcinoma.

  • 作者:赵阳青;詹美云

    Objective.To study the therapeutic T cell vaccine for the treatment of chronic hepatitis B by improving the cellular immunization of HBsAg vaccine with the coexpression of the preS1 (1- 42) and the Core (1- 144) antigen of HBV in E.coli.Methods.The genes of HBcAg (1- 144) and preS1 (1- 42) were amplified and fused by PCR.This fused gene was inserted in the prokaryotic expression vector pET 11d and expressed in E.coli.Results.It was showed by SDS PAGE that the protein molecular weight of the coexpression product was about 20 kD,20% of all bacteria protein.The monoclonal antibodies against core and preS1 antibody could react with this fused protein by Western blot technique respectively.The fused gene was verified by sequencing.Under the immune electron microscopy,this fused protein is typical particles of HBcAg but in an aggregated form.Conclusion.The results might aid for studying T cell immunotherapeutic vaccine for chronic hepatitis B.

  • 作者:董菁;成军;王勤环;施双双;王刚;斯崇文

    Objective.To search for genomic DNA sequence of the augmenter of liver regeneration (ALR) of rat.Methods.Polymerase chain reaction (PCR) with specific primers was used to amplify the sequence from the rat genome.Results.A piece of genomic DNA sequence and a piece of pseudogene of rat ALR were identified.The lengths of the gene and pseudogene are 1508 bp and 442 bp,respectively.The ALR gene of rat includes 3 exons and 2 introns.The 442 bp DNA sequence may represent a pseudogene or a ALR related peptide.Predicted amino acid sequence analysis showed that there were 14 different amino acid residues between the gene and pseudogene.ALR related peptide is 84 amino acid residues in length and relates closely to ALR protein.Conclusion.There might be a multigene family of ALR in rat.

  • 作者:陈文明;吴垠;朱嘉芷;刘敬忠;谭淑珍;夏成青

    Objective.To investigate the frequency of p16 and p15 gene methylation in multiple myeloma (MM),and its relationship with bone marrow cell apoptosis and clinical outcome.Methods.Twenty two patients with MM were studied to detect p16 and p15 gene methylation.Methylation specific polymerase chain reaction (MSP) was used to detect gene methylation,and terminal transferase mediated dUTP nick end labeling (TUNEL) was used to detect cell apoptosis.Results.p16 and /or p15 gene methylatoin was detected in 10 of 22 patients (45.4%).There were 3 patients with p16 gene methylation,9 patients with p15 gene methylation,and 2 patients with both genes methylation.The incidence of methylation of p15 gene was higher than that of p16 gene (P< 0.05).The patients with p16 and/or p15 gene methylation had a delayed cell apoptosis,poor response to chemotherapy,and a short overall survival (OS).Conclusion.The methylation of p16 and/or p15 gene plays a key role in MM apoptosis pathogenesis.The patients with both p16 and p15 gene methylation had a poor prognosis.

  • Objectives. In order to identify the relationship between telomerase and the biological effect of radiation injury,and investigate the role of human telomerase catalytic subunit gene (hEST2) reverse transcriptase(RT) segment in the expression of telomerase activity. Methods. Tumor HeLa cells, KB cells and A431 cells were employed to measure the change in telomerase activity after 60Co ray irradiation at RNA level and protein level. Quantitative PCR and Northern blotting were used to determine the expression of hEST2 RT segment that encodes seven motifs of the human telomeres, a PCR based telomeric repeat amplification protocol (TRAP)was used to assay telomerase activity after exposure to radiation. Results. Both of telomerase activity and the expression hEST2 RT segment were decreased with increasing dosage of radiation. In addition, testing the expression of motifs domain is similar to the measurement of telomerase activity. Conclusion. The detection of the hEST2 RT segment by Northern blotting and quantitative PCR are new methods for testing telomerase activity. Furthermore, radiation can cause a dose dependent decrease in telomerase activity. The effect of radiation on telomerase is one possible reason for the death of cancer cells after irradiation.

  • Objective. The aim of this study is to investigate the functional relationship between filamin, a known actin bind-ing protein, and myosin and the effects of filamin on the interaction between myosin and actin. Methods. Ultra-centrifugation method was used to investigate the binding of filamin to both phosphorylated and unphosphorylated myosins. Mg-ATPase activities of both phosphorylated and unphosphorylated myosins in the presence and absence of aefn were measured to observe the effects resulted from fdamin-actn and filamin-myosin interactions. Results. It was found that fiiamin is also a myosin binding protein. Filamin inhibited the actin activated Mg-ATPase activity of phosphorylated myosin and stimulated Mg-ATPase of phosphorylated myosin in the absence of actin;in addition, filamin stimulated Mg-ATPase activity of unphosphorylated myosin in both the presence or absence of actin.

  • 作者:王立清;胡盛寿;李澎;谢峰;吴清玉;郭加强

    Objective. To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. Methods. To produce the model of acute myocardial ischemia, we partially ligated the left anterior decending (LAD)coronary artery of canine hearts between lst. and 2nd. diagonal branches and then performed transmyocardial revascularization in this region with Ho- YAG laser. Myocardial contrast echocardiography was made with a new generation of ultrasound contrast agent and second harmonic imaging of this region before, after ischemia and after laser revascularization. Pictures were taken with “R” wave trigger skill.Results. Acoustic density derterming in the ischemia region (anterior wall)with MCE (myocardial contrast echocardiography )was obviously decreased( 5.40 ± 1.81) after the LAD was ligated, as compared with before( 11.69 ±1.61, P < 0.01 ). It was increased remarkably after transmyocardial laser revascularizatuon (TMLR) ( 11.2 ± 2.01, P< 0. 01 )as compared with that when ischemia and approximated to that before ischemia(P > 0.05). There were no differences in acoustic density in the lateral wall(as control)among these comprehensive three periods(P > 0.05). Contrast in the laser region developed one cardiac cycle ahead of that in the non-ischemic normal region.Conclusion. Acute ischemic myocardium can be peffused by oxygenated blood from the left ventricle through HoYAG laser channels. Evidence of blood perfusion through laser channels during systolic phase was detected, and myocardial contrast ultrasonography using intravenous perfluorocarbon-exposed sonicated dextrose albumin may be regarded as a reliable method in the study of transmyocardial revascularization.

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