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Biomedical subjects

Wei Liu

Publications and source records attributed to Wei Liu.

At least 415 records · Page 23Linked to original sources
PubMed2003

[The application of indirect immuno-fluorescence assay in the diagnosis of severe acute respiratory syndrome].

OBJECTIVE: To explore the temporal profile of serum antibody against coronavirus in patients with severe acute respiratory syndrome (SARS), and to evaluate the reliability of indirect immuno-fluorescence assay (IFA) in the diagnosis of SARS. METHODS: Clinically confirmed SARS patients, suspected SARS patients, and controls were included in the study. IFA was used to detect the serum antibody against SARS coronavirus. General information about the subjects was collected using a standard questionnaire. RESULTS: The positive rates of specific IgG and IgM against SARS virus within 10 days after onset of the disease were 55.1% and 16.3% respectively and then increased up to 89.8% for IgG and 65.3% for IgM. After 25 days of the onset of the disease, 90.9% patients became positive for both IgG and IgM. Results from chi-square for trend test revealed that the positive rates of both IgG and IgM increased with time (chi(2) for trend = 16.376, P = 0.00005 for IgG; chi(2) for trend = 28.736, P = 0.00000 for IgM). Sensitivity, specificity and agreement value of IFA regarding the diagnosis of SARS were all higher than 90%. CONCLUSION: IFA can be used to assist diagnosis of SARS after 10 days of the onset of disease.

Antibodies, Viral↗
PubMed2003

[Amplification of RIT1 in hepatocellular carcinoma and its clinical significance].

BACKGROUND & OBJECTIVE: Previous study has demonstrated that high frequent gain of 1q was detected in hepatocellular carcinoma (HCC), 1q21-22 was identified as the minimum overlapping amplified region and might contain the candidate oncogenes involved in HCC. RIT1 gene is located in 1q21.3 region and is a member of Ras subfamily. RIT1 protein is similar to Ras protein in molecular structure and functions. It was speculated that RIT1 gene might be a candidate oncogene in HCC. So, the amplification of RIT1 gene was examined in HCC and was linked with the clinical indicators in this study to explore the possible functions of RIT1 gene in HCC development and progression. METHODS: The fluorescence quantitative polymerase chain reaction(FQ-PCR) method was established successfully. The number of RIT1 gene DNA copies was examined in the tumor tissues and its paratumor tissues from 43 patients with HCC by PE ABI 7000 Sequence Detector. The ratio of the number of RIT1 gene DNA copies between the tumor tissue and its paratumor tissue represented the extent of amplification of RIT1 gene DNA. RESULTS: RIT1 gene DNA was amplified in 11 cases (25.6%)among 43 patients. The mean survival time (15 months) of the RIT1 gene-amplification group is significantly shorter than that (34 months) of the non-amplification group (P = 0.0009); furthermore, the pathological grade and the extent of liver cirrhosis were significantly different between the RIT1 gene-amplification group and the non-amplification group (P< 0.01). CONCLUSION: The amplification of RIT1 gene might be one of the activation ways in HCC and might play an important role in HCC development and progression.

Adult↗
PubMed2003

Application of ovarian transposition during hysterectomy.

OBJECTIVE: To study the optimal position and method for ovarian transposition and its benefits and indications. METHODS: We performed ovarian transposition in 34 patients from August 1989 to December 2000. Twelve patients were diagnosed with stage Ib to IIa cervical cancer, 4 had stage Ia endometrial carcinoma, 12 had stage III to IV endometriosis, 4 had myoma of uterus, 1 had dysfunctional uterine bleeding, and 1 had an ovarian granulosa cell tumor. Surgery went as follows: the ovary was dissociated by clamp, the skin was incised and a tunnel was made, then the ovary was translocated to the subcutaneous site. In the cases of benign lesions, the ovarian vessel pedicel went in through the abdominal cavity, but in malignant tumors, it went out through the peritoneum. RESULTS: In both cases (benign lesions or malignant tumors), the short-term and long-term endocrine function of the translocated ovary remained normal. Furthermore, patients could supervise their translocated ovary themselves. CONCLUSIONS: Subcutaneous ovary transposition might prevent not only implantation of gastrointestinal cancer but also the extension of pelvic carcinoma to the ovary. Because of the shallow transposition and the incision scar, it is easy for patients to supervise themselves. Moreover, the site of the ovary is easy to locate for ultrasound examinations. Thus, it can obtain the goal of early prevention for cancer. Subcutaneous ovarian transposition with skin incision is the optimal selection and suitable for all patients with various gynecologic diseases in which ovary removal is not necessary.

Adult↗
PubMed2003

[Nanobacteria in serum, bile and gallbladder mucosa of cholecystolithiasis patients].

OBJECTIVE: To find the distribution of nanobacteria in the serum, bile and gallbladder mucosa of cholecystolithiasis patients. METHODS: The infection rate of nanobacteria was identified by ELISA in the serum samples from 338 healthy people and 76 patients with cholecystolithiasis (chi(2) = 0.89, P > 0.05). Nanobacteria were cultured from the bile samples in 57 patients with cholecystolithiasis and 18 non-cholelithiasis patients and identified by immunohistochemical staining and TEM (chi(2) = 29.80, P < 0.05). Forty samples of gallbladder mucosa randomly selected from the 57 cholecystolithiasis patients were identified by immunohistochemical staining and compared with the corresponding bile samples. RESULTS: The infection rate of nanobacteria was 8.0% and 31.6% for the serum samples of the healthy people and cholecystolithiasis patients, respectively. The positive rate of nanobacteria in the bile samples was 61.3% and there was no significant difference in the bile of the cholecystolithiasis patients and the control group (61.4% vs. 61.1%). Fourteen positive patients had infection of nanobacteria in the gallbladder mucosa, submucosa, and calcific field. CONCLUSIONS: The infection rate of nanobacteria was 8% in the serum samples from the healthy people. There are nanobacteria in the serum, bile, and gallbladder mucosa. The infection of the nanobacteria may result in calcification and fibrosis of the gallbladder.

Adult↗
PubMed2003

[Microsurgical treatment of the clinoid and para-clinoid ICA aneurysms].

OBJECTIVE: To explore the microsurgical treatment of the clinoid and para-clinoid ICA aneurysms we analyzed operative techniques, outcome, and indication. METHODS: Clinical data and follow-up outcome of 10 the clinoid and para-clinoid ICA patients were reviewed. In this study there were 3 patients with clinoid ICA aneurysms, five with ophthalmic aneurysms, two with superior hypophyseal aneurysms and one with posterior ICA wall aneurysm. RESULTS: On follow-up (3 - 14 months, mean 7 months), 7 patients were in an excellent condition and two in a good condition; and one died of stroke postoperatively. Patients were clipped satisfactorily, as confirmed by postoperative angiogram in hospital except that one patient died of stroke. CONCLUSIONS: Clinoid and para-clinoid ICA aneurysms were surgical indications. Further clarifications of aneurysms and their indications can improve outcome.

Adult↗
PubMed2003

[Development of a measurement and control system of human centrifuge].

OBJECTIVE: To develop measurement and control system for human centrifuge to simulate arbitrary hypergravity curves. METHOD: The human centrifuge is controlled by the upper and lower level computers. The measurement and control computer is as upper, and the real-time controller as lower. RESULT: The system performance could satisfy the requirement of the human centrifuge. CONCLUSION: The measurement and control system can achieve a high control precision. It is safe, reliable and easy to operate.

Centrifugation↗
PubMed2003

Hepatitis gene chip in detecting HBV DNA, HCV RNA in serum and liver tissue samples of hepatitis patients.

OBJECTIVE: To study the preparation of diagnostic gene chip for detecting hepatitis B virus (HBV) and hepatitis C virus (HCV) and its accuracy in detecting HBV DNA and HCV RNA in serum and liver tissues. METHODS: The probes, which depend on the conservative gene fragment of hepatitis virus, was designed, synthesized and spotted on the modified glass. The probes and some other control probes were assembled on the diagnostic microarray of hepatitis virus. The gene of hepatitis virus, purified from blood or tissue, was labeled with fluorescence and hybridized to the microarray. The hybridized microarry was scanned with microarray scanner and the diagnostic result was analyzed from the scanning data. Fourty patients with hepatitis B virus and 40 healthy people or 40 patients with hepatitis C virus were subjected to detection of HBV DNA and HCV RNA with the hepatitis virus gene chip by the double-blind method. Paraffin liver specimens obtained from 99 cases of posthepatitic cirrhosis were used to detect HBV DNA. The liver tissues and serum from 15 cases of chronic hepatitis B were used to detect HBV DNA. Simultaneously, HBsAg and HBcAg were detected in the serum by fluorescence microparticle quantitation, HBV DNA and HCV RNA in the serum by PCR, and HBcAg in liver tissues by immunocytochemistry or HBV DNA by in situ molecular hybridization. RESULTS: Chip detection of serum specimens showed that 30 patients were HBV DNA positive and 10 HBV DNA negative in the 40 patients with HBV positive, 25 patients were HCV RNA positive and 15 patients were HCV RNA negative in the 40 patients with HCV positive, and all were HBV and HCV negative in the 40 healthy people. In 15 patients with HBV marker positive who were subjected to liver biopsy, 15 patients were detected HBV DNA positive in serum by gene chip, 15 patients HBcAg positive in liver tissues by immunocytochemistry, 14 patients HBV DNA positive in liver tissues by in situ molecular hybridization, and 14 patients HBV DNA positive in liver tissues by gene chip. Paraffin liver tissues specimens from the 99 patients with posthepatitis B cirrhosis showed that 67 patients were detected HBcAg positive by immunocytochemistry, 53 patients HBV DNA positive by in situ molecular hybridization, and 46 patients HBV DNA positive by gene chip. In the 46 patients, 40 patients were detected HBV DNA and HBcAg positive by in situ molecular hybridization and immunocytochemistry, 6 patients only HBcAg positive, and 33 patients HBcAg negative. CONCLUSIONS: The designed diagnostic gene chip can be used to simultaneously detect serum HBV DNA and HCV RNA, but the positive rate of HCV RNA diagnosed by this chip is lower. The gene chip can detect HBV DNA in serum and in liver tissue.

DNA, Viral↗
PubMed2003

[Expression of IL-2 and TNF-alpha in the liver and the effect of injection of these cytokines on liver fibrosis in mice infected with Schistosoma japonicum].

OBJECTIVE: To detect the expression of IL-2 and TNF-alpha in the liver at different period postinfection of Schistosoma japonicum and their effect on liver fibrosis after supplementary injection of these cytokines. METHODS: Mice were infected with schistosome cercariae and divided into 3 groups. Two groups were injected (i.p.) every other day with IL-2 and TNF-alpha respectively for consecutive 4 wk. The third group and an uninfected group of normal mice were regarded as control. The ABC immunohistochemistry and pathologic image multimedia quantification system were applied to detect activity of IL-2 and TNF-alpha. RESULTS: The level of IL-2 and TNF-alpha in the liver in infected but untreated group slowly decreased (from 8, 11, 14 to 18 wk). The supplementary injection of the cytokines at 6 wk postinfection in the two groups increased the cytokines significantly, the level of IL-2 or TNF-alpha was higher at 1-8 wk after the last injection than that of both infected and uninfected control groups (P < 0.01). The granulomatous inflammation and fibrosis in the livers of the two groups were slighter than that of the control. CONCLUSION: At the 6th wk postinfection with egg deposition, exogenous supplementation with TNF-alpha or IL-2 induces enhanced expression of the two kinds of cytokines, corresponding to a diminished degree of the liver granulomatous inflammation and fibrosis.

Animals↗
PubMed2003

Myasthenia gravis in pediatric and elderly patients.

OBJECTIVE: To determine whether the clinical and pathologic characteristics and prognoses of myasthenia gravis (MG) patients below 15 years differ from those patients over 50 years after thymectomy. METHODS: We reviewed the registry material of 30 pediatric and 32 elderly MG patients after thymectomy, including their age, sex, clinical classification, pathological types, and prognoses. The Chi-square test or Wilcoxon's rank-sum test was used to determine the statistical differences between the children and elderly groups. RESULTS: No significant difference was seen in sex distribution between the two groups. (Chi-square test, P=0.625), but there were differences in clinical classification: more type I was observed in the pediatric group than in the elderly group, but more type II or III was seen in the elderly group (Wilcoxon's rank-sum test, P<0.001). As to pathological types, the pediatric group was also significantly different from the elderly group (Chi-square test, P<0.01). All of the patients (100%) in the pediatric group had thymus hyperplasia, but in the elderly group more than half (56.26%) were found to have thymoma (benign or malignant). The prognoses after thymectomy were better in the pediatric group than in the elderly group (Wilcoxon's rank-sum test, P<0.001). CONCLUSIONS: Because the prognoses are generally better than those of the elderly patients, we should be careful when operating on pediatric patients of ocular type. The elderly patients tend to receive more aggressive treatment because of more severe generalized types often associated with thymoma and poor prognoses. Both pediatric and elderly patients are seldom associated with other autoimmune disease.

Adolescent↗
PubMed2003

[Experimental study on constructing small-caliber artery by tissue engineering approach].

OBJECTIVE: To investigate the possibility of constructing small-caliber artery by means of tissue engineering. METHODS: Cell-PGA mixtures were made by separately seeding 1 x 10(7) smooth muscle cells and 5 x 10(6) endothelial cells isolated from neonate umbilicus onto PGA scaffold, the cell-PGA constructs were wrapped around a silicone tube before its implantation subcutaneously to nude mice and the mice were sacrificed in 2 and 6 weeks. The tissue engineered artery (TEA) were examined both grossly and immunohistochemically. RESULTS: The gross appearance of TEA was similar to that of the natural counterparts; histologic and immunohistochemical analyses of the neoformed tissues revealed a typical artery structure, including the presence of EC at the luminal surface and the presence of SMC and collagen in the wall. CONCLUSION: TEA with histology similar to natural vessel can be constructed by tissue engineering.

Animals↗
PubMed2003

[A case-control study on natural-resistance-associated macrophage protein 1 gene polymorphisms and susceptibility to pulmonary tuberculosis].

OBJECTIVE: To investigate association between the natural-resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms and susceptibility to pulmonary tuberculosis (TB) in Chinese Han population. METHODS: Hospital-based case-control study design was adopted. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) technique were used to type three NRAMP1 polymorphisms (INT4, D543N and 3'UTR). Information on related factors of tuberculosis was collected using a pre-tested standard questionnaire. Univariate and multivariate unconditional logistic analyses were conducted using SPSS for window software package. Totally, 110 cases of TB were selected during April 2001 to June 2002, with an average age of (27.7 +/- 12.7) years. Also, 180 cases of healthy control were selected, aged (27.3 +/- 9.2) years in average. Locus of NRAMP1 polymorphism was analysed with univariate method. RESULTS: Univariate analysis demonstrated that the D543N G/A and 3'UTR TGTG+/del genotype occurred more frequently in the cases than in the controls, with crude odds ratios (OR) (95% CI) of 2.22 (1.03 - 4.78) and 1.93 (1.14 - 3.26), respectively. No significant association was observed between TB and INT4 polymorphisms. In multivariate analysis, associations of TB and D543N G/A and 3'UTR TGTG+/del genotypes remained, adjusted for exposure history and bacille Camette-Guérin immunization. Adjusted OR (95% CI) was 3.04 (1.12 - 8.27) and 2.36 (1.20 - 4.64), respectively. Still, no significant association between INT4 polymorphisms and TB was found. CONCLUSION: Polymorphisms of D543N and 3'UTR locus in NRAMP1 gene might affect their susceptibility to TB in Chinese Han population.

Adolescent↗
PubMed2003

[A study on oxidative DNA damage and lipid peroxidation in patients with tuberculous pleurisy].

OBJECTIVE: To explore the levels of mononuclear cell oxidative DNA damage and lipid peroxidation in patients with tuberculous pleurisy. METHODS: The mononuclear cell DNA damages in pleural effusion and peripheral blood of 28 patients with tuberculous pleurisy and in peripheral blood of 25 healthy persons were detected by single cell gel electrophoresis (comet%). The levels of total antioxidative capacity (TAC) in supernatant of pleural effusion and blood plasma of 28 patients and in blood plasma of 25 healthy persons were measured by o-phenanthroline colorimetric analysis. The contents of malondialdehyde (MDA) of blood plasma from 28 patients and from 25 healthy persons were measured by thiobarbituric acid colorimetric analysis. The differences between groups were analyzed by t test. RESULTS: The comet percentage of mononuclear cells in pleural effusion from patients with tuberculous pleurisy was (41.3 +/- 14.5)%, which was significantly higher than that in the peripheral blood (21.2 +/- 4.2)% (P < 0.01); The level of TAC in supernatant of pleural effusion was (5 172 +/- 1 195) U/L, which was lower than that in the blood plasma (8 656 +/- 1 592) U/L (P < 0.01). There was a negative correlation between the comet percentage of mononuclear cells and the level of TAC (r = -0.425, P < 0.05) in pleural effusion. The comet percentage of mononuclear cells in peripheral blood and the content of MDA in blood plasma from patients were (21.2 +/- 4.2)% and (8.25 +/- 1.37) micro mol/L, which were significantly higher than those from the controls (8.9 +/- 3.7)% and (4.46 +/- 0.93) micro mol/L respectively (P < 0.01); The level of TAC in blood plasma was (8 656 +/- 1 592) U/L, which was lower than that from the controls (10 610 +/- 1 399) U/L (P < 0.01). There were negative correlations between the level of TAC in blood plasma and the comet percentage of mononuclear cells in peripheral blood or the content of MDA in blood plasma (r = -0.438, -0.413, P < 0.05), and there was a positive correlation between the comet percentage of mononuclear cells in peripheral blood and the content of MDA in blood plasma (r = 0.899, P < 0.01). CONCLUSION: There is oxidation/antioxidation imbalance in patients with tuberculous pleurisy, namely oxidative stress, with inadequate total antioxidative capacity, particularly in the diseased pleural cavity.

Adult↗
PubMed2003

[Biological characterization of immortalized porcine chondrocytes by introduction of telomerase].

The aim of this project was to acquire a clonal immortalized porcine chondrocyte cell line and to determine its biological characterization. Porcine auricle chondrocytes were infected with a retroviral vector pBABE-hTERT followed by selection with 2 micrograms/ml puromycin. RT-PCR and PCR-ELISA performed on separated colonies showed a cell line (TL1) with high and stable ectopic expression of hTERT. The growth curve, HE staining, flow cytometry, and tumorigenicity were analyzed to define the biological characterization of the immortalized chondrocytes. TL1 cells showed an increase in cellular viability and the reduction in apoptosis. But there was no malignant transformation and tumor development in nude mice. The changes of chondrocyte marker expression in this cell line revealed that it remained unstable phenotype. So high ectopic expression of hTERT is able to extend the life span of chondrocytes, but it unable to keep their differentiated phenotype during serial monolayer culture in vitro.

Aggrecans↗
PubMed2003

[Detection of myocardial lesion in patients with acute ammonia poisoning].

OBJECTIVE: To find a better index for detecting myocardial lesion in patients with acute ammonia poisoning. METHODS: Cardiac troponin T (cTnT), creatine kinase (CK), creatine kinase-MB isoenzyme (CK-MB), and electrocardiogram (ECG) were determined and compared in patients with acute ammonia poisoning and healthy controls. RESULTS: In severe ammonia poisoning patients, the levels of cTnT [(1.285 +/- 2.650) micro g/L], CK [(257.636 +/- 362.719) IU/L], CK-MB [(20.909 +/- 19.770) IU/L] were significantly higher than those in healthy control [(0.035 +/- 0.014) micro g/L, (82.050 +/- 36.302) IU/L, (8.350 +/- 2.455) IU/L respectively, P < 0.05]. The levels of cTnT, CK and CK-MB in mild ammonia poisoning patients [(0.039 +/- 0.016) micro g/L, (78.200 +/- 28.401) IU/L and (8.467 +/- 2.669) IU/L respectively], and moderate ammonia poisoning patients [(0.054 +/- 0.043) micro g/L, (99.786 +/- 71.941) IU/L and (9.429 +/- 3.857) IU/L were not significantly different from those of healthy controls (P > 0.05)]. cTnT positive detection rate (68.2%) was significantly higher than CK (36.4%), CK-MB (31.2%) and ECG (31.2%) (P < 0.05). CONCLUSION: cTnT is a better index to detect myocardial lesion in severe ammonia poisoning.

Acute Disease↗
PubMed2003

[Characteristics of zero point of charge of volcanic ash soils in Changbaishan and Wudalianchi].

The characteristics of the zero point of charge (ZPC) of volcanic ash soil profiles in Changbaishan and Wudalianchi was studied and discussed by means of potentiometric titration curves. The results showed that the two volcanic ash soils had not only a little variable charg, but also a little permanent charge. The clay fractions of the volcanic ash soils carried both variable and permanent charges. The ZPC of eeach layer in both soil profiles all lied in the acid side of titration curve, and increased with increasing soil depth. However, the ZPC displacements (sigma i) decreased with increasing soil depth. The ZPC of surface layer in both soil profiles was lower than that of the volcanic ash soils in foreign countries, but obviously higher than that of Loess soil in the Northwest and of black soil in the Northeast China. The variation of ZPC and delta i was affected not only by the deposition of long-rang tropospheric eolian dust from the Asian continent, but also by the accumulation of soil organic matter. Their combined effect was the main reason to the decrease of ZPC and sigma i the increase of sigma i in Changbaishan and Wudalianchi volcanic ash soils.

Hydrogen-Ion Concentration↗
PubMed2003

[The cloning of mouse FasL gene and expression in chondrocytes].

AIM: To clone mFasL cDNA, then insert it into retrovirus expression system pLNCX(2), and express mFasL cDNA in chondrocytes to study its function. METHODS: RT-PCR was applied to amplify mFasL cDNA from the total RNA of activated mouse spleen lymphocytes. The cDNA was inserted into a T-cloning vector, then subcloned into pLNCX(2). After transfection of chondrocytes, expression of FasL cDNA was detected by FACS, and activity of expressed product was analyzed by single mixed lymphocyte reaction(SMLC). RESULTS: mFasL cDNA fragment of 0.855 kb was successfully cloned and verified by sequencing. The transfection efficiency of mFasL cDNA in chondrocytes determined by FACS was 60.64%. Expressed product could evidently inhibit SMLC of allogeneic lymphocytes. It's stimulating index (SI) reduced to 11.71% as compare with the untransfected chondrocytes. CONCLUSION: Cloned recombinant pLNCX(2)-FasL can effectively express mFasL in chondrocytes, and can evidently inhibit SMLC of allogeneic lymphocytes.

Animals↗