Biomedical subjects

W Zhang

Publications and source records attributed to W Zhang.

At least 811 records · Page 45Linked to original sources

PubMed1998

[Open heart surgery without cross clamping aorta].

Open heart surgery without cross clamping aorta under normothermic or hypothermic cardiopulmonary bypass was performed in 167 patients in which there were more than ten kinds of cardiac diseases. The characteristics of the procedure included only vena cava blocked and aorta unclamped with beating heart or artificial evoked ventricular fibrillation. It diminished myocardial ischemia and reperfusion injuries maximally. There were no low cardiac output syndrome, severe arrhythmia and complications of brain except two patients died postoperatively. The operative mortality rate was 1.1% (2/167). The advantages, disadvantages and safety of this method are discussed briefly in this paper.

Adolescent↗

PubMed1998

[Morphometric analysis of gap junctions of the cell membrane in human uterine smooth muscle at term].

OBJECTIVE: To study the changes of the gap junctions (GJS) in the uterine smooth muscle cells at various stages of labor, and its relationship with the onset of labor. METHODS: 18 women (38 to 41 gestational weeks) were divided into three groups: not-in-labor, pre-labor, active in labor and six cases in each group. The uterine myometrium tissues were observed by transmission electron microscopy (TEM) and lanthanum tracing method. RESULTS: The lengths and areas of GJS in uterine corpus and lower segment in the active in labor group were significantly larger than that of the other 2 groups, but there was no significant difference between the not-in-labor and pre-labor groups. The area but not the lengths of GJS in corpus was significant larger than that in the lower segment in the active in labor group. CONCLUSION: The great increase of length and areas of GJS in all parts of the uterine smooth muscle was closely correlated with onset of labor.

Adult↗

PubMed1998

[Influence of ischemic preconditioning of heart on ischemia/reperfusion injury of rabbit lung].

The influence of ischemic preconditioning of heart on ischemia-reperfusion injury of 16 Japanese big-ear-rabbit lungs were studied. The results showed: 1. Experimental group had a significant reduction in wet/dry weight ratio; 2. It had a significant increase in PaO2. 3. It had a minimal intraalveolar neutrophil infiltration in comparison with the control group. These data suggestes that the ischemic preconditioning of heart can lighten the ischemia-reperfusion injury of rabbit lungs.

Animals↗

PubMed1998

[Effect of manganese on the growth and development of rat offspring].

Effects of Manganese exposure to pregnant rats on the growth and development of their offsprings were as follows: (1) the gain of body weight and brain weight in the high dose Mn-exposed offspring was significantly lower but the ratio of brain to body weight was significantly higher; (2) in Morris Water Maze Test, the average latency to find the hidden platform in the high dose Mn-exposed offsprings was obviously reduced during the first 5 days. But on the non-platform test day, a much longer length of swimming in the quadrant in which the hidden platform was located previously, although no difference was found for the total distance between them; (3) the immunoreactivity of glial fibrillary acid protein and the average density of its products in hippocampus of both the low and high dose Mn-exposed groups, especially of the high dose one, was significantly higher than that of the control group.

Animals↗

PubMed1998

[Study of a new type of material substituted for human hard tissues-hydroxyl poly calcium sodium phosphate: histologic report implants in mandible of animals].

This study was aimed to evaluate the histocompatibility of hydroxyl poly calcium sodium phosphate (HPPA) preliminarily. HPPA and hydroxylapatite were implanted in the mandibular defect in dogs. The implant-bone interface was observed by using stereomicroscope and decalcified histologic sections. The result demonstrates that HPPA has well-osseous integrated property after being implanted into bone tissues. This suggests that HPPA might be a new material of future excellence in substitution for human hard tissues.

Animals↗

PubMed1998

[Expression of glial cells line-derived neurotrophic factor in the central nervous system of rat].

Glial cell line-derived neurotrophic factor (GDNF) iss a distant member of the transforming growth factor-beta, originally isolated by virtue of its ability to induce dopamine uptake and cell survival in cultures of embryonic ventral midbrain dopaminergic neurons, and more recently it has been shown to be a potent neurotrophic factor for motor neurons. However, the distribution of this molecule in the central nervous system (CNS) is not known yet. In the present study, the expression of GDNF of rat was investigated by using immunohistochemistry. GDNF immunoreactive fibers or bodies were found in molecular layer and Purkinje layer of cerebellum. In the spinal cord, neuronal expression was found widely, especially in ventral horn, Clarke's column. GDNF was also expressed in fiber terminals of I and II lamella of dorsal horn. Additionally, GDNA expression was found in the ependymal epithelium and neuroglia of spinal cord. The nuclei of neuroglia were stronger than perikaryon. The neurons in cerebral cortex showed very weak immunoreaction. We conclude that GDNF is expressed in many different cellular systems within the CNS, suggesting the multiple functions of GDNF in the adult CNS.

Animals↗

PubMed1998

[Simultaneous determination of lead and copper in food by differential potential stripping with the presence of emulgent OP].

The effect of different surfactants on the stripping analysis of Pb and Cu was studied. The optimum condition for simultaneous determination of Pb and Cu in foods by the differentital potential stripping analysis in the 0.3 mol/L HCl media and by using emulgent OP as spike agent was described. The contents of Pb and Cu in soft drinks, fermented wine and flavourings with added standards were determined directly by synchronous mercury plating. The recovery of the added standard samples were 95%-105%, and relative standard deviation was 0.8%-7.9%. The proposed method has been applied to the sample analysis.

Acetic Acid↗

PubMed1998

[The changes of plasma calcitonin gene-related peptide level in women with normal pregnancy and pregnancy induced hypertension].

OBJECTIVE: To study the change of calcitonin gene-related peptide (CGRP) concentrations in maternal plasma of the normal pregnant women and patients with pregnancy induced hypertension (PIH) and relationship with CGRP and pathogenesis of PIH. METHODS: The plasma levels of CGRP in 59 cases of normal pregnant women (normal pregnancy group), 57 cases of PIH (PIH group), and 10 cases of nonpregnant women (control group) were determined with a sensitive radioimmunoassay. RESULTS: Plasma CGRP levels in normal pregnancy group increased with advance for the gestational week, reached the peak value (76.84 +/- 27.75 ng/L) in late trimester; plasma CGRP levels in PIH group decreased with series degree of PIH, levels of CGRP in moderate (49.76 +/- 23.11 ng/L) and severe PIH (46.35 +/- 22.32 ng/L) were significantly lower than that in mild PIH (71.28 +/- 21.98 ng/L) and the normal late pregnancy, the differences were significant (P < 0.005). There was no correlation between CGRP levels and the mean arterial pressure (MAP). CONCLUSIONS: The change of CGRP may play an important role in the pathogenic mechanism of PIH.

Adult↗

PubMed1998

[Study of magnesium and calcium levels of plasma and within erythrocyte before and after magnesium sulfate treatment in patients with pregnancy induced hypertension].

OBJECTIVE: To study the changes of calcium and magnesium levels in patients with pregnancy induced hypertension (PIH) and the therapeutic effect of magnesium sulfate (MgSO4). METHODS: The calcium and magnesium levels in plasma and erythrocytes of 36 patients with PIH and 14 healthy gravidi in their late pregnancy were determined and the changes after 4 hours infusion of MgSO4 as well. RESULT: Plasma calcium decreased significantly in moderate and severe PIH patients, but calcium increased and magnesium decreased in their erythrocytes. After MgSO4 infusion for PIH, magnesium levels in both plasma and erythrocytes increased, while calcium increased in plasma and decreased in erythrocyte to normal levels. CONCLUSION: Magnesium deficiency is the basis of calcium and magnesium disturbances in PIH, and MgSO4 treatment may improve the situation effectively.

Adolescent↗

PubMed1998

[Study of interleukin-6 and tumor necrosis factor-alpha levels in maternal serum and amniotic fluid in patients with preterm premature rupture of membrane].

OBJECTIVE: To study the change and clinical significance of maternal serum and amniotic fluid interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) levels in patients with chorioamnionitis and premature rupture of membrane (PROM). METHODS: Twenty normal term-pregnant women as control, and fourty-six women with PROM were enrolled for study. Maternal serum and amniotic fluid IL-6, TNF-alpha levels were measured by radioimmunoassay and enzyme-labeled immunosorbent assay (ELISA). Chorioamnionitis was diagnosed histologically. RESULTS: The maternal serum IL-6 levels and amniotic fluid IL-6, TNF-alpha levels were higher in PROM group than that of control (P < 0.01). There was significant positive correlation between maternal IL-6, amniotic fluid IL-6, TNF-alpha levels and the duration from rupture of membrane, (the longer was time, the higher were the maternal IL-6 and the amniotic fluid IL-6. TNF-alpha). There were 12 cases with chorioamnionitis in patients with PROM and their maternal and amnotic fluid IL-6, TNF-alpha levels were higher than that of non-chorioamnionitis (P < 0.01-0.05). CONCLUSION: IL-6 and TNF-alpha levels in maternal serum and amniotic fluid are valuable clinical indices for identification of chorioamnionitis in patients with PROM.

Adult↗

PubMed1998

[Telomerase activity in liver cancer and the adjacent tissue].

OBJECTIVE: To investigate the possibility of using telomerase as a tumor marker for human primary hepatocellular carcinomas (HCC). METHODS: Human liver specimens, comprising 33 HCC and adjacent peritumoral tissues, 4 hepatic metastases and the adjacent peritumoral tissues, 6 benign liver lesions and 6 normal liver tissues, were examined for telomerase activity by TRAP assay based on PCR. RESULTS: Thirty of 33 HCC and 9 of 33 adjacent tissue specimens were positive for telomerase activity with a positive rate of 90.9% and 27.3%, respectively. Four hepatic metastatic cancer and 2 adjacent tissues were positive. Telomerase activity was negative in 6 nomal liver tissues and 5 of 6 benign liver lesions. There was no correlation between the clinical stage of HCC and their telomerase activity. CONCLUSION: Positive telomerase activity occurs in the majority of HCC examined. It can be used as a tumor marker in the diagnosis of HCC.

Biomarkers, Tumor↗

PubMed1998

[Malignant mixed mesodermal tumors of the ovary: a clinical analysis of 12 cases].

OBJECTIVE: To explore the clinical characteristics, treatment and prognostic factors of patients with malignant mixed mesodermal tumors of the ovary (MMMTO). METHODS: Clinical data of 12 patients with MMMTO between 1983-1997 were reviewed retrospectively. The median age of the patients was 50.7 years. According to FIGO staging system (1985), there were 4 cases in stage II, 6 in stage III and 1 in stage IV. Staging was unclear in the remaining case. Heterologous and homologous elements were present in the primary ovarian tumors in 4 and 8 of the 12 patients, respectively. All patients received cytoreductive surgery. Eleven of them received postoperative chemotherapy and 3 of these eleven patients received additional radiotherapy of pelvic field. RESULTS: The median survival of this group of 12 patients was 24 months. The 2- and 5-year survival rate was 33.3% (4/12) and 8.33% (1/12), respectively. The 2-year survival rate of stage II and III was 50% and 33.3% respectively. One patent in stage IV died within 1 year. Four of the 8 patients with homologous histology survived over 2 years while all the 4 cases with heterologous histology died within 2 years. Five of the 11 patients (45.5%) received combination therapy died within 1 year while 1 patient treated with surgery alone died within 6 months. CONCLUSIONS: The prognosis of MMMTO is rather poor. Surgery combined with chemotherapy and/or radiotherapy seems to be a better choice of approach. The histological tpyes of tumor and stage of the disease are related to prognosis.

Adult↗

PubMed1998

[Enhanced antitumor effect of suicide gene therapy by SCF, GM-CSF gene transfer in vivo and its immunological mechanism].

OBJECTIVE: To explore an efficient approach to enhance antitumor effect of suicide gene therapy by improving in vivo antigen presenting function and their immunological mechanisms. METHODS: The CT26 colon adenocarcinoma was treated with CD/5FC system combined with the mGM-CSF or/and mSCF gene transfection, and the antitumor effects were evaluated by the tumor growth, tumor-free mouse rate, splenic CTL activity and cytokine expression of tumor milieu. RESULTS: The tumor burden was reduced significantly and higher survival rate was obtained after the combined treatment. It was found that some cytokines(including mIL-4, mIL-2, mIFN-gamma and mTNF-alpha) were expressed in the tumor milieu after mGM-CSF or/and mSCF gene transfection following CD/5FC treatment but not in the control groups. The cytotoxic activity against CT26 cells of spleen cells of the treated mice was significantly incressed. CONCLUSION: The combination of mSCF or/and mGM-CSF gene transfection enhances the antitumor effect of the suicide gene therapy. Such an enhancement is associated with the induction of specific antitumor immune response and secretion of cytokines in tumor milieu.

Adenocarcinoma↗

PubMed1998

[Study of telomerase activity in colorectal carcinomas].

OBJECTIVE: To investigate the telomerase activity in human colorectal carcinoma and tumor-adjacent tissue and to investigate the possibility of telomerase as tumor biological marker. METHODS: A total of 60 human colorectal tissue specimens, comprising 37 carcinomas, 3 benign lesions and 20 tumor-adjacent tissue specimens were examined for telomerase activity by telomeric repeat amplification protocol(TRAP) assay. RESULTS: No telomerase activity in 20 tumor-adjacent tissues and 3 benign lesions was detected. However, of 37 colorectal carcinoma specimens, 35 were positive for telomerase activity with a 94.6% positive rate. CONCLUSION: The data suggest that telomerase is a tumor specific gene marker, and may play an important role in early diagnosis and treatment of colorectal carcinomas.

Biomarkers, Tumor↗

PubMed1998

[The effect of ectopic HCG on microvessel density in gastric carcinoma].

OBJECTIVES: To study the effect of ectopic HCG on microvessel density in gastric carcinoma using immunohistochemical staining with anti-beta-HCG polyclonal antibody and anti-factor VIII related antigen(FVIII RAg)antibody. METHODS: A total of 40 specimens resected from patients with gastric carcinoma was investigated by immunohistochemical staining with a anti-beta-HCG polyclonal antibody and a monoclonal antibody against FVIII RAg. The expression of beta-HCG and the microvessel density(the average number of microvessel in three areas of highest vascular density at 400 x magnification) in various regions of the histologic specimens were studied. RESULTS: Fifteen (37.5%) of the 40 gastric carcinomas was positive for beta-HCG protein in tumor tissue. beta-HCG protein was negative in the tumor-adjacent and in normal tissue. The mean microvessel density was 27.4 +/- 7.1 in the tumor, 11.9 +/- 5.4 in tumor-adjacent and 4.8 +/- 1.5 in normal tissues (P < 0.05-0.01). There was a close correlation with beta-HCG positivity and microvessel density (MVD). There was no correlation between the degree of tumor cell differentiation and beta-HCG expression, nor was a correlation between it and MVD. High expression level of beta-HCG and MVD was significantly associated with hematogenous metastases. CONCLUSION: Ectopic HCG expression may have angiogenic effect which, in turn, may facilitate hematogenous dissemination of gastric cancer.

Adenocarcinoma↗

PubMed1998

[Study on expression of IRF-1 gene in human leukemia with RT-PCR and the silver sequence techniques].

OBJECTIVE: To explore preliminarily the changes of IRF-1 gene expression in leukemias. METHODS: The expression of IRF-1 gene in 24 leukemia patients and 3 leukemic cell lines were studied with RT-PCR and the silver sequence techniques. RESULTS: No expression of IRF-1 gene in 3 patients, and significantly decreased expressions in 5 patients and in HL-60 and HIMeg cell lines were revealed. CONCLUSION: The mechanism of human leukemogenesis may be partly associated with no or low-expression of IRF-1 gene.

DNA-Binding Proteins↗

PubMed1998

[The construction and application of adenovirus vector coexpressing the heterodimer of human IL-12].

OBJECTIVE: To construct the recombinant adenovirus vector co-expressing the heterodimer of human interkeukin-12. METHODS: The full-length cDNA encoding human IL-12 subunits p40 or p35 was cloned by RT-PCR separately. The cDNA was ligated with encephalomyocarditis internal ribosome entry site (IRES), placed under the control of CMV promoter, and inserted into E1-substituted adenovirus vector pAx1cw to produce the bicistronic coexpression vector. Subsequently, the hIL-12 recombinant adenovirus vector was cotransfected into 293 cells together with EcoT22I-digested Ad5 DNA-TPC, and the replication-deficient hIL-12 recombinant adenoviruses was generated efficiently by homologous recombination. RESULTS: The human IL-12 recombinant adenoviruses were obtained with the titers of 2.1 x 10(9) pfu/ml. 48 hours after the infection of the 293 cells, HepG2 cells and human primary skin fibroblasts with hIL-12 recombinant adenoviruses, the hIL-12 expressions were detected by ELISA (30-50 ng/10(6) cells/24 h). The expressed hIL-12 could stimulate the in vitro proliferation and IFN-gamma production of human PMNC. CONCLUSION: Prepared hIL-12 recombinant adenovirus vector can express biologically active hIL-12 and can be potentially used in cancer gene therapy.

Adenoviruses, Human↗

PubMed1998

[Effects of different expression levels of fibronectin on biological behavior of tumor cells].

OBJECTIVE: To study the effects of fibronectin(FN) on tumor cell proliferation, adherence and invasion. METHODS: FN cDNA was introduced into a transitional carcinoma cell line 253J which expressed low level of FN, and 253 FN line which expressed higher level of FN was established. The changes of cellular proliferation in vitro were observed. Adhesiveness to the extracellular matrix was detected by MTT method. Hemotypic adhesion was investigated by detachment assay and invasiveness of the cells was observed with Boyden Chamber before and after FN cDNA gene transfection. RESULTS: The growth rate of 253-FN was decreased as compared with its parental cell 253J. Hemotypic adhesion was significantly increased. The adhesiveness of the cells to extracellular matrix was enhanced. Invasion assay showed that invasioness of 253-FN was decreased. CONCLUSION: This study suggested a correlation between FN expression and its biological behavior. With increased FN level, malignant phenotype was changed and invasive ability was inhibited.

Carcinoma, Transitional Cell↗