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Biomedical subjects

S Gu

Publications and source records attributed to S Gu.

At least 73 records · Page 4Linked to original sources
PubMed1998

[The purification and application of Epstein-Barr virus gp125].

Epstein-Barr virus (EBV) virion capsid antigen (VCA) gp125 as a diagnostic antigen was expressed in infected cells by recombinant vaccinia virus. The presence of IgA antibody to VCA of EBV was tested by ELISA in sera from nasopharyngeal carcinoma (NPC) patients and normal individuals. The ELISA consisted of three steps involving test serum, mouse monoclonal antibody to human IgA and rabbit anti-mouse IgG. The antibody titers of sera determined by this way correlated well with those by IF. The GMT by ELISA was 12 times higher than that by IF. Furthermore, efforts to develop gold-conjugated immunosorbent assay (GCISA), which is a more sensitive assay for measuring IgA antibody to VCA, has met with initial results.

Antibodies, Viral↗
PubMed1998

[Purification of hepatitis B virus antigen and its application in detection of human serum antibody].

A recombinant plasmid DNA pBV220/eAg provided by professor Zhou Jian was transferred into DH5 alpha celes. The effectively expressed strain was harvested after cloning. It was then incubated in 30 degrees C for 3 hrs and 42 degrees C for 6 hrs, the HBeAg protein was induced. After purification of the protein by DEAE-Sepharose Fast Flow chromatography, the purified protein was analyzed by SDS-PAGE electrophoresis and Coomassic brilliant blue R250 stain and only one single protein band was seen, Its specificity was demonstrated by Western-blot and Immunodot. 49 HBeAb positive sera of hepatitis B patients could be specifically detected with the purified HBeAg by ELISA and immunostrip assay, but the latter was more sensitive and specific.

Antibodies, Viral↗
PubMed1998

[Expression of Epstein-Barr virus membrane antigen in CHO cell].

A recombinant plasmid, pCMV/MA, was generated by isolating the Epstein-Barr Virus(EBV) membrane antigen(MA) gene with anchor sequence removed from pSV40/MA and cloning it into pcDNA3, with MA gene and Neomycin gene under the control of CMV promoter and SV40 promoter respectively. CHO cells were transfected with pCMV/MA using liposome and then grown in DMEM medium in the presence of G418. Two clones highly expressing MA were obtained. EBV-MA was purified from the medium of CHO cells by ammonium sulfate precipitation. Western-blot showed that the molecular weight of proteins expressed were about 340 kD and 220 kD. It could specifically react with anti-MA monoclonal antibody in indirect immunofluorescent and immunodot assay. The yield of MA was estimated to be 1.9 micrograms/ml per day by SDS-PAGE scanning and Lowry methods. The optimal culture condition of the CHO cells was to use medium supplemented with 10% serum until 80% cell confluence, then with 2%-5% serum and collected medium continually. The genetic stability of the cells was confirmed by freeze--revival and culture without G418. The purified MA was used to immunize mice and the geometric mean titer of the specific antibody was 1:180, while the positive rate of antibody was 100%.

Animals↗
PubMed1998

[Correction of spectral interferences in inductively coupled plasma atomic emission spectrometry with a modified chemometric method based on matrix projection].

A modified chemometric method based on matrix projection was developed to correct the spectral interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES). The accuracy of the correction was significantly improved by reevaluating the residuals. The excellent analytical results for some rare earth elements proved the method fairly feasible.

English Abstract↗
PubMed1998

[Study of spectral interferences of REEs with the matrix of dy for a high resolution ICP-AES].

The spectral interferences of the matrix of Dy on other REEs have been studied for a high resolution ICP-AES with a grating of 3600 grooves/mm. 66 analytical lines of 14 REEs have been selected as the prominent lines in the spectral interference studies. Three kinds of databases for Dy lines have been established for the spectra search and recognition. Thus, these databases can provide information of Dy lines accurately and conveniently.

English Abstract↗
PubMed1997

Safety, efficacy, and acceptability of medical abortion in China, Cuba, and India: a comparative trial of mifepristone-misoprostol versus surgical abortion.

OBJECTIVE: We investigated safety, efficacy, and acceptability of an oral regimen of medical abortion compared with surgical abortion in three developing countries. STUDY DESIGN: Women (n = 1373) with amenorrhea < or = 56 days chose either surgical abortion (as provided routinely) or 600 mg of mifepristone followed after 48 hours by 400 micrograms of misoprostol. This is the appropriate design for studying safety, efficacy, and acceptability among women selecting medical abortion over available surgical services. RESULTS: The medical regimen had more side effects, particularly bleeding, than did surgical abortion but very few serious side effects. Failure rates for medical abortion, although low, exceeded those for surgical abortion: 8.6% versus 0.4% (China), 16.0% versus 4.0% (Cuba), and 5.2% versus 0% (India). Nearly half of failures among medical clients were not true drug failures, however, but surgical interventions not medically necessary (acceptability failures or misdiagnoses). Women were satisfied with either method, but more preferred medical abortion. CONCLUSION: Medical abortion can be safe, efficacious, and acceptable in developing countries.

Abortifacient Agents↗
PubMed1997

Effect of a mechanical vs a pharmacologic increase in aortic pressure on coronary blood flow and thrombolysis induced by IV administration of a thrombolytic agent.

This study was designed to compare the effect of a mechanical vs a pharmacologic increase in BP on coronary artery blood flow and thrombolysis induced by IV administration of recombinant tissue plasminogen activator. We employed a canine model of coronary thrombosis induced by injection of radioactive blood clot in the left anterior descending coronary artery. Subsequently, all dogs underwent phlebotomy to decrease systolic BP to 75 mm Hg and this decreased coronary blood flow by 50%. BP was increased to 130 mm Hg by norepinephrine (NE) infusion or by inflation of a Fogarty catheter placed in the descending aorta. Interventions with NE or with a Fogarty balloon catheter increased coronary artery blood flow to similar values and rates of coronary thrombolysis were similar. However, cardiac output was significantly higher with NE. These results indicate coronary clot lysis is dependent on perfusion pressure and coronary blood flow, not cardiac output.

Animals↗
PubMed1997

[Chemical constitutents of Podocarpus imbricatus BI. (II)].

From Podocarpus imbricatus five compounds were isolated and identified as 2"-O-rhamnosylvitexin (I), hinokiflavone (II), ecdysterone (III), beta-sitosteryl heptadecoate (IV) and daucosterol(V) on the basis of spectral studies (UV, IR, 1HNMR, 13CNMR, MS) and chemical reactions. I, II, III, IV are obtained from this plant for the first time, and IV is obtained as beta-sitosteryl odd number carboxylic ester for the first time.

Biflavonoids↗
PubMed1997

[Purification and application of viral capsid antigen of Epstein-Barr virus].

The viral capsid antigen of Epstein-Barr virus was purified from sf9 cells infected with recombinant Baculoviruses and the purified protein was used to establish ELISA and immuno-strip method for detection of VCA/IgG and VCA/IgA antibodies in human sera. A sensitive, specific and cost-effective method has been developed for serological mass survey.

Antibodies, Viral↗
PubMed1997

[Study on atomic emission spectrum and spectral interferences of rare earth elements with a high resolution inductively coupled plasma atomic emission spectrometer.--II. Spectral intererences of Samarium matrix].

The rare earth elements play a very important role in today's manufacture and life. For their complex spectra it is difficult to determine the trace elements in rare earth element matrix. This work investigated the spectral interferences of samarium matrix on other rare earth elements with a high resolution inductively coupled plasma atomic emission spectrometer. A lots of spectrum information and spectral interferences were obtained, which are quite useful in the selection of analytical lines that free of spectral interferences and the elimination of the concomitant's interferences.

English Abstract↗
PubMed1996

Norrie-Warburg syndrome: two novel mutations in patients with classical clinical phenotype.

Norrie-Warburg syndrome (NWS) is a rare X-linked disorder characterized by blindness, which is invariable, deafness and mental disturbances, which are present occasionally. We describe here two novel mutations, a missense mutation (C126S) and a 1-base pair insertion (insT466/T467), together with a recurrent mutation (M1V), found in patients presenting with the classical clinical phenotype of NWS. All three mutations are likely to result in prominent structural changes of the norrin protein.

Blindness↗
PubMed1995

Induction of antitumor immunity and treatment of preestablished tumor by interleukin-6-gene-transfected melanoma cells combined with low-dose interleukin-2.

Transfer of cytokine genes into tumor cells has proven a valuable approach for cancer treatment. In order to generate a more effective cancer vaccine, we transfected the human interleukin-6 (IL-6) gene into B16 melanoma cells. A B16 cell clone secreting the highest level of IL-6 was obtained by G418-resistant selection, limiting dilution and IL-6 assay. The IL-6-gene-transfected tumor cells exhibited in vitro growth inhibition, reduced tumorigenicity and decreased metastatic competence. After immunization with the inactivated IL-6-gene-transfected vaccine, the murine cytotoxic T lymphocyte activity, natural killer activity and lymphokine-activated killer activity increased markedly. After treatment with the vaccine, the tumor-bearing mice showed significant growth inhibition of subcutaneous tumor, reduction in pulmonary metastases and extension of survival time. The above therapeutic effect was better when low-dose IL-2 was administered simultaneously, although this dosage of IL-2 had no in vivo antitumor effect. These data demonstrated that IL-6-gene-transfected cancer vaccine has a potent antitumor effect via efficient induction of antitumor immunity, and a better therapeutic effect could be achieved when the vaccine is combined with low-dose IL-2 as adjuvant.

Animals↗
PubMed1995

Flows of social support and health status among older persons in China.

As a consequence of the political, social, and economic developments in contemporary China, there have been considerable changes in the patterns of flows of social support between Chinese older people and their significant others. There is evidence that Chinese elders are now under strong pressure to provide more social support, instrumental support in particular, to their children and other relatives while they receive less. Such a change in the direction of flows of social support has been reported to worsen the elders' health. This paper describes the general pattern of social support both to and from the Chinese elders, using data of a probability sample survey conducted in Wuhan, China in 1991. The association between social support, both receiving and providing, and old-age health status is also analysed within a multivariate framework. The results of two probit models suggest that emotional support received plays a crucial role in affecting an elder's health status, while instrumental support received does not have explicit impacts. In addition, there is no empirical evidence that increased instrumental support from elders has worsened their health status as reported.

Adaptation, Psychological↗