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Biomedical subjects

Z Liu

Publications and source records attributed to Z Liu.

At least 613 records · Page 34Linked to original sources
PubMed1999

[Comparative study of HLA-DRB1 allele in patients with chronic bronchitis and bronchial asthma].

OBJECTIVE: To make a comparative study of HLA-DRB1 allele frequencies in the cases of chronic bronchitis and bronchial asthma. METHODS: The authors investigated 74 patients with chronic bronchitis and 64 patients with bronchial asthma from among the Han people in Shanxi province. PCR/SSP technique was used for HLA-DRB1 typing, and the patients' data were compared with the normal controls'. RESULTS: The frequency of HLA-DRB1*1201/1202(24.32%) was significantly increased in the chronic bronchitis group(P<0.01),and the frequency of HLA-DRB1*1501/1502(23.44%) was significantly increased in the bronchial asthma group(P<0.05). The frequencies of other DRB1 alleles were not significantly increased in these groups. CONCLUSION: The results indicate that HLA-DRB1*1201/1202 allele is associated with chronic bronchitis and HLA-DRB1*1501/1502 allele is associated with bronchial asthma in the patients among the Hans in Shanxi province.

Alleles↗
PubMed1999

Effect of tumor necrosis factor-alpha and interleukin-2 on spleen lymphocyte migration in mouse skin.

Tumor necrosis factor-alpha (TNF-alpha) and interleukin-2 (IL-2) are reported to enhance lymphocyte binding to endothelial cells in vitro. We examined these two agents on lymphocyte migration in vivo. Spleen lymphocytes were radiolabeled with tritiated uridine (3H-UR) and then injected i.v. into mice. Each cytokine (TNF-alpha or IL-2) or both cytokines were then injected intradermally on the back of mice. The results demonstrated that TNF-alpha stimulates lymphocyte migration in vivo in dose-dependent fashion. Kinetic analysis demonstrated that migration with TNF-alpha started at 3 h, peaked at 6 h, followed by a gradual decline back to baseline at 24 h. IL-2, on the other hand, was nearly inactive, and did not augment lymphocyte migration over and above that induced by TNF-alpha when both cytokines were injected together.

Animals↗
PubMed1999

In vitro study of the effects of endothelin-1 on human dental pulp cells.

OBJECTIVE: To study the effect of Endothelin-1 (ET-1) on cell proliferation in primary cultures of human dental pulp cells; the cell mechanism of mitogen; and collagen synthesis. METHODS: Primary cultures of human dental pulp cells; Thiazolyl Blue Tetrazolium Bromide (MTT) test to investigate cell proliferation; measurement of calcium ions in human dental pulp cells with the calcium-sensitive dye fluo-3; enzyme-linked immunosorbent assay and avidin-biotin complex immunocytochemical assay for collagen synthesis in human dental pulp cells. RESULTS: Incubation of cultures with ET-1 resulted in a dose-dependent increase in cell proliferation over control (unstimulated) cultures. In addition ET-1 increased the Ca2+ concentration in human dental pulp cells, which cannot be inhabited by Verapamil. The finding demonstrated that collagen type I synthesis of human dental pulp cells was increased by ET-1. CONCLUSIONS: ET-1 played a crucial role in pulp restoration of lesions and had an effect on mitogen and differentiation of human dental pulp cells.

Cell Division↗
PubMed1999

[The relationship of serum hepatitis B virus DNA load in HBsAg positive pregnant women to the intrauterine infection of newborns].

OBJECTIVE: To study the relationship of serum hepatitis B virus (HBV) DNA load in HBsAg positive pregnant women to intrauterine infection of their newborns. METHODS: Serum HBV DNA were determined by dot-blot hybridization in 185 HBsAg positive pregnant women. Serum HBsAg were tested by ELISA in their newborns within 24 hours after birth. RESULTS: The prevalence of intrauterine HBV infection of the newborns was associated with the HBV DNA level of the mothers. With the increase of serum HBV DNA load, the risk of fetal intrauterine infection was increasing. CONCLUSION: Fetal exposure to high level of maternal HBV DNA is one of the important determinant of intrauterine infection.

DNA, Viral↗
PubMed1999

[Study of nylestriol effect on bone histomorphometric parameters in ovariectomized rats].

OBJECTIVE: To investigate the response of trabecular bone of ovariectomized (OVX) rats to nylestriol. METHODS: Thirty-three female Wistar rats were randomly divided into three groups, 11 rats in each: nylestriol-treated group (E), OVX and the control (C). The OVX rats were used as a model for osteoporosis. After being fed with nylestriol for 3 months, all rats were sacrificed. The effect of nylestriol on bone microarchitecture and dynamics were studied by bone histomorphometry. RESULTS: The data suggest that trabecular bone volume, mean trabecular width, density and cortical thickness were remarkably reduced in OVX group (P < 0.05) while tetracycline labeled surface, osteoid surface and bone turnover rate were increased in comparison with that in C group (P < 0.05). The bone turnover rate and trabecular bone volume were improved with the treatment of nylestriol for 3 months in the OVX rats(P < 0.05). CONCLUSIONS: Trabecular bone volume and bone turnover rate can be improved by 3 month administrations of nylestriol in osteoporotic rat models.

Animals↗
PubMed1999

[Conversion from a tridimensional surface to a plane for measuring expanded skin area with computer-aided technique].

OBJECTIVE: To seek a reliable and practical method to measure the expanded skin area. METHODS: In our technique, the three-dimensional surface overlaid with the expanded skin was converted to a flat one through a special surface molding. This irregular plane area was scanned digitally to the computer and measured by means of counting its total pixels. With the areas of the underlying base and the defect measured in the same way, we could determine whether the extra tissue after expansion was sufficient for clinical repair at any stage of expansion. RESULTS: The deviation of this protocol was less than 3 percent at most in our preliminary reliability demonstration. CONCLUSION: This protocol can be used to estimate the expanded skin area in the clinical and experimental applications.

Adult↗
PubMed1999

[Vaginal hysterectomy for large uterus].

OBJECTIVE: The technique and experience of vaginal hysterectomy for large uterus of 25 cases was reported. METHODS: Vaginal hysterectomy for 25 cases of uterine fibroids and adenomyosis were performed. The uterine sizes enlarged as large as 6-16 weeks of pregnancy, mobile, no adhesion by estimation. The technique used for reducing the uterine bulk included bisection, myomectomy, morcellation and coring. The most common way to reducing the uterine bulk was bisection combined with myomectomy and morcellation. RESULTS: Twenty four cases of vaginal hysterectomy were performed successfully. The average weight of uterus for the 25 cases was 360 g(range from 155 g to 755 g), the mean time for the operation was 95 minutes(range from 60 to 150 minutes), the average quantity of blood loss was 150 ml (range from 50 to 400 ml), the average admission duration of postoperation was 5.3 days(range from 3 to 8 days). CONCLUSION: Vaginal hysterectomy is a safe and effective option for removing enlarged uterus. The successful operation was related to the uterine sizes, mobile, operator' skill and experiences.

Adult↗
PubMed1999

[Expression of focal adhesion kinase in lymphatic endothelial cells of metastasis].

This study was directed at the expression of focal adhesion kinase (pp125FAK) which is located together with vinculin and talin in the spot of cellular adhesion. The authors' intention was to collect reliable data on this important kinase in the signal pathways so as to provide in-depth materials for exploring the mechanism of tumor metastasis to lymphatic vessels. The immunohistochemical method was used to study the expression of FAK in lymphatic endothelial cells of metastaltci adenocarcinoma of rectum and its adjacent lymph-nodes. The result demonstrated that lymphatic endothelial cells expressed pp125FAK when lymphatic vessels were invaded by cancer cells. Reaction production was located in the cytoplasm. This study provides that there was a strong correlation between the expression of FAK in lymphatic endothelial cells and the metastasis of cancer to lymphatic vessels.

Adenocarcinoma↗
PubMed1999

[Comparative study on early revascularization of membranous and endochondral onlay bone grafts in the rat].

OBJECTIVE: To investigate the disparity in early revascularization of the membranous and endochondral bone grafts. METHODS: Twenty Wistar rats were randomly divided into two groups of 10 each. Full-thickness cranial (membranous) and split-thickness iliac crest (endochondral) onlay bone grafts were placed subperiosteally onto the snout of the animal without bony fixation. At 7 and 14 days after grafting the bone grafts together with the recipient sites were harvested. Revascularization was studied utilizing opacifying injection and computerized image analysis technique. RESULTS: The extent of vascularization at 7 days was 11.88% and 22.33% in membranous and endochondral bone grafts, respectively, and they developed to be 15.93% and 34.93% at 14 days, respectively. CONCLUSION: The results indicated that endochondral bone grafts were more rapidly revascularized than membranous bone grafts at 7 and 14 days (P < 0.05). Differences in graft architecture are theorized to account for the relationship between the vascularization and volume maintenance in the bones of different embryonic origin.

Animals↗
PubMed1999

Interstitial brachytherapy using iridium-192 for malignant brain tumors: clinical results.

OBJECTIVE: To determine the effects and toxicity of interstitial brachytherapy using iridium-192 on brain malignant gliomas. METHODS: Between January 1992 and January 1995, 56 patients with anaplastic astrocytoma and glioblastoma multiforme were treated with stereotactic brachytherapy using temporary high-activity iridium-192 sources. RESULTS: The median survival for patients receiving brachytherapy was 28 months. The survival rates at 1, 2, 3 years were 92.8%, 83.9% and 71.4% respectively. CONCLUSIONS: Brachytherapy may improve the control of local tumor and prolong the survival, when used in deep malignant brain gliomas, by temporary implanted high doses of iridium-192 sources.

Adult↗
PubMed1999

[Surgical treatment of frontal lobe epilepsy--40 cases].

OBJECTIVE: To compare the methods and outcome of the treatment of frontal lobe epilepsy (FLE). METHODS: We combined such techniques, as intraoperative electrocorticography (ECoG), corpus callostomy(CCS), and multiple subpial transection(MST) to improve the surgical results. When preoperative semiology suggested the involvement of the bilateral frontal lobe or ECoG detected bilaterally synchronized epileptic discharged, anterior corpus callosotomy was performed before the main surgical procedure. MST was applied to the unresectable motor or involved speech zone. This technique was also useful for the treatment of widely disseminated epileptic zone. Satisfactory results were obtained in surgical treatment of FLE. RESULTS: One month after operation, most patients were free from seizure. No severe complications and operative death occurred. Follow up lasted for 0.5 to 3 years(mean 2.5 years). Seizure free was noted in 19 patients(47.5%), seizure attack less than 3 times per year or no real attack in 11(27.5%), significant reduction of seizure attack in 6(15%); and no change in 4 (10%). The total effective rate was 90%. CONCLUSION: Indicated by ECoG, combined resection with corpus callosotomy or multiple subpial transection is an effective method for FLE.

Adolescent↗
PubMed1999

[Direct genotyping of an hereditary persistence of fetal hemoglobin deletion and rapid prenatal diagnosis of the fetus at-risk for compound heterozygote of this defect with beta-thalassemia in a Chinese family].

OBJECTIVE: To investigate the relationship between genotype and phenotype of a deletional hereditary persistence of fetal hemoglobin(HPFH) found in a Chinese family and explore an approach to rapid prenatal diagnosis for compound heterozygote of HPFH defects with beta-thalassemia. METHODS: By using the PCR-based method with three primers bridging a HPFH breakpoint and reverse dot blot (RDB) for detecting beta-thalassemia mutations, a Chinese family who had a propositus of six years old with intermediate thalassemia and requested prenatal diagnosis for the second pregnancy were screened. RESULTS: The propositus carried the HPFH deletion determinant inherited from her mother, and a codons 14-15 (+G) frameshift mutation causing beta-thalassemia from her father. Of six members in this family screened for this type of HPFH deletion, four were positive. Prenatal diagnosis of the fetus showed the same results as that of the propositus. An advice of termination of pregnancy was given and the result of prenatal diagnosis was confirmed in the DNA samples obtained after abortion. CONCLUSIONS: This is the first time to have performed prenatal diagnosis of Chinese family at-risk for compound heterozygotes for beta-thalassemia and HPFH in mainland China. The PCR assay for directly detecting the HPFH deletion is rapid and inexpensive and can be used as a routine in HPFH carrier screening and prenatal diagnosis.

Adult↗
PubMed1999

[Distinguished medical students of Boji Hospital in Guangzhou (1855 - 1900)].

Guangzhou Boji Hospital (The Canton Hospital) was the most famous western medical hospital established in 1835. John G. Kerr, an American doctor with the Presbyterian Mission, was the founder of the hosptial. He became the director of Boji Hospital in 1855 and worked there for 44 years. Chen Mengnan, Kang Guangren, Sun Yatsen (Zhongshan), Zheng Shiliang, Zhang Zhujun and Shi Jingran were medical students of Boji Hospital in this period. They had made important contributions to China during the rapid changing society of the late Qing dynasty.

China↗
PubMed1999

[Loss of heterozygosity on chromosomes 17 and 16 in primary hepatocellular carcinomas].

OBJECTIVE: 38 cases of hepatocellular (HCC) carcinomas were studied to detect loss of heterozygosity(LOH) at specific areas on chromosome 17 and 16, the possible relations were discussed between LOH and HBV/HCV infection and clinic-pathology of HCC. METHODS: We detected LOH on chromosome 17 and 16 by using PCR based microsatel lite polymorphism analysis. RESULTS: 31 of 38(82%) tumors were deleted for at least one locus of 6 loci on chromosome 17. Loci D17S520 (17p12-p13.3) and TP53(17p13.1) occurred more frequent LOH(> 50%). But only one locus of the four loci on 17q occurred frequent LOH (40%), the other three loci occurred lower frequent LOH (< 30%). 26 (72%) of detected 36 HCC were positive for at least one locus of five loci on chromosome 16, and all 5 loci occurred higher frequent LOH (> 50%). The most frequent LOH(71%) occurred at D16S413(16q24). Relations were observed between LOH of p53 gene and HCV infection and tumor size, but no relations between LOH at other locus on chromosome 17 and 16 and HBV/HCV infection and clinical-pathology of HCC. CONCLUSION: LOH on chromosome 17, especially LOH of p53 gene may play a role in the development of HCC. These results indicated that there may be more than one tumor suppressor gene related to the development and progression of HCC on chromosome 17 and 16.

Adult↗
PubMed1999

[Effect of antral gastritis and cytokines on Helicobacter pylori associated duodenal ulcer].

OBJECTIVE: To investigate the role of cytokines and antral gastritis in the development of duodenal ulcer that associated with Helicobacter pylori (H. pylori) infection. METHOD: 48 cases of duodenal ulcer with different degrees of H. pylori infection (35 cases with H. pylori infection and 13 patients without H. pylori infection,) were investigated by measuring the level of gastric mucosal cytokines and the degree of antral gastritis. RESULTS: Compared with H. pylori negative cases, the patients with H. pylori positive duodenal ulcer had higher level of gastric mucosal IL-8, TNF alpha, MPO, MDA and severer antral gastritis. IL-8, TNF alpha, MPO and MDA were positirely correlated with H. pylori density and they were highly correlated with each other. However IL-6 did not have such specific properties. CONCLUSION: Cytokines may be an important factor that links gastritis and duodenal ulcer associated with H. pylori infection.

Adult↗
PubMed1999

[Modulatory effect of transforming growth factor-beta and Rhein on glucose transporter-1 in human glomerular mesangial cells].

OBJECTIVES: To identify the glucose transporter-1 (GLUT1) in human glomerular mesangial cell and to evaluate the modulatory role of TGF-beta 1 and Rhein on the function of GLUT1 in mesangial cells. METHODS: GLUT1 in human glomerular mesangial cells was identified by RT-PCR for its mRNA expression. Cell surface protein of GLUT1 had been demonstrated by immunofluorescence staining and flow cytometry analysis using specific antibody. The uptake rate of glucose by mesangial cells was detected using the [3H]-2-DG. Glucose uptake specificity was confirmed by the co-incubation with unlabeled 2-DG or GLUT1 inhibitor Phlorhizin. RESULTS: Human glomerular mesangial cells expressed functional GLUT1. TGF-beta 1 stimulated [3H]-2-DG uptake and GLUT mRNA expression in mesangial cells. The increase in [3H]-2-DG uptake and GLUT1 mRNA expression by TGF-beta 1 in mesangial cells were markedly abolished by the addition of Rhein in a dose dependent manner, while Rhein showed no effect on the glucose uptake in mesangial cells cultured in normal glucose medium. CONCLUSIONS: Functional GLUT1 does present in human mesangial cells. TGF-beta 1 stimulates the glucose uptake by enhancing the GLUT1 mRNA expression in mesangial cells. This effect could be antagonized by Rhein. These results suggest that Rhein might be a hopeful drug for patients with diabetic nephropathy.

Anthraquinones↗
PubMed1999

Blocking effect of puerarin on calcium channel in isolated guinea pig ventricular myocytes.

OBJECTIVE: To identify whether Puerarin (Puer) has blocking effects on L-type calcium channel. METHODS: We used whole-cell recording of patch-clamp techniques to analyse calcium channel current in ventricular myocytes isolated from Langendorff guinea pig hearts by collagenase. RESULTS: In control group, peak calcium channel current was decreased by 10.6% and 29.8% at 5, 10 min of recording time, respectively. For the same period, 0.1 mmol/L Puer reduced calcium current by 23.9% and 72.4%. 0.1 and 1 mmol/L Puer inhibited the amplitude of peak Calcium channel current by 40.6% and 63.2% after perfusing for 10 min. Compared with control group in which "rundown" phenomenon was observed, Puer also demonstrated its blocking effect on L-type channel. While washout of Puer with perfusing solution, calcium channel current went down further instead of recovery. Current-voltage (I-V) curves showed that the levels of calcium channel current were obviously decreased by Puer (both 0.1 mmo/L and 1 mmo/L) form -40 mV to +10 mV. CONCLUSION: Puer has blocking effect on L-type calcium channel in a concentration dependent manner.

Animals↗