Biomedical subjects

X He

Publications and source records attributed to X He.

At least 109 records · Page 6Linked to original sources

PubMed2001

The role of factor XI in a dilute thromboplastin assay of extrinsic coagulation pathway.

Blood coagulation has been thought to be composed of both intrinsic and extrinsic pathways. Recent evidence strongly supports the critical role of the extrinsic pathway in the initiation of blood coagulation. This investigation established an assay that examines the role of FXI in the thromboplastin-initiated (extrinsic) coagulation based on this new concept. Plasma clotting times were measured at different concentrations of thromboplastin with activated FXII inhibited (FXIIa-inhibited Diluted Thromboplastin Time, FXIIaiDTT). Only at low concentrations of thromboplastin was FXIIaiDTT of FXI-deficient plasma significantly prolonged than that of normal plasma. Depletion of FXI from normal plasma prolonged its FXIIaiDTT and replenishment of FXI shortened it. FXIIaiDTTs of both FVIII-deficient and FIX-deficient plasma were remarkably prolonged, and addition of normal plasma dose-dependently shortened it. Furthermore, earlier alpha-thrombin inhibition was directly correlated with decreasing FXa generation. The amount of FXa production was: platelet-rich plasma > platelet-poor plasma > FXI-deficient plasma. Therefore, our findings from the FXIIaiDTT assays not only support the critical role of extrinsic pathway in blood coagulation initiation, but also demonstrate the importance of FXI as an amplifier of thrombin generation in thromboplastin-initiated coagulation.

Blood Coagulation↗

PubMed2001

[Finite element analysis of spine biomechanics].

In this paper is summarized and classified the recent great progress in the research of spine biomechanics analysis. In addition, the relevant clinical significance as well as some possible research trends of finite element model establishment are also clarified. As a theoretical method, only by close links with clinical practice can finite element analysis really help explain the onset and development of diseases and forecast the curative effects.

Biomechanical Phenomena↗

PubMed2001

[Exogenous pGH gene localization on chromosomes of the transgenic pigs].

The pUC19-OMT plasmids were cut by Ssp 1 and the products in 900 bp were recovered from low-melting agarose gel and used as probes which were labeled by Digoxigenin. After being denatured, the probes were dropped on the chromosome samples which were also denatured to anneal with them. The anti-digoxigenin antibodies labeled with colloidal gold were used to act with the chromosome samples. In order to localize the exogenous pGH genes(porcine growth hormone gene) on chromosomes detected with optical microscope and improve the sensitivity, digoxigen gold signals are amplified by silver precipitation. After calculating the number of silver grains on every chromosome under the optical microscope, we analyzed the data with statistical methods. The results show that the integrating sites of exogenous pGH genes are very different among the positives. However, it is clear that the exogenous genes in one are always of the tendency to integrate in one specific site on a certain chromosome. These data are of great significance for studying the site-specific integration and the expression efficiency of exogenous genes in the future research.

Animals↗

PubMed2001

[Development of the heterogeneous photocatalytic reactor in water treatment].

Based on the history and the functions of the heterogenous photocatalytic reactors, three categories were discussed. The emphasis was put on the employment of the reactors designed for the practice in recent years. It was pointed out that the study and the design of the reactors were one of the cores in the process of the application of the photocatalytic oxidation techniques. And the trend of this technology was also predicted.

Catalysis↗

PubMed2001

Anti-Human type II collagen CD19+ B cells are present in patients with rheumatoid arthritis and healthy individuals.

OBJECTIVE: To determine the frequency and repertoire of CD19+ B cells capable of producing antibodies reactive to type II collagen (CII) in synovial fluid (SF) and peripheral blood (PB) of patients with rheumatoid arthritis (RA) and PB of healthy control individuals. METHODS: CD19+ B cells were isolated and activated to secrete immunoglobulins (Ig) by CD4+ T cells. Frequencies of anti-CII B cells were determined by limiting dilution analysis. The isotype and cross-reactivity of the antibodies produced were determined by ELISA. RESULTS: SF and PB from 5 patients and PB from 4 healthy controls were analyzed. Anti-CII CD19+ B cells were identified in all samples tested. In the RA SF, the percentage of activated B cells reactive to human CII was significantly higher than in the PB of patients with RA (p < 0.05) or controls (p < 0.01). A majority of anti-human CII B cells from patients' SF secreted IgG isotype, whereas most anti-human CII B cells in PB of patients and controls secreted IgM. The anti-CII B cells, regardless of source, are usually reactive to both native and denatured human CII, to different types of human collagens, and to type II collagens from different species. CONCLUSION: Anti-CII CD19+ B cells responsive to activated helper T cells are present in both patients with RA and healthy individuals. However, these B cells, especially those secreting the IgG isotype, accumulate in the inflamed joints of RA patients.

Adult↗

PubMed2001

[Exercise tolerance in relation to ventilatory drive and respiratory muscle function in COPD].

OBJECTIVE: To assess the relationships between exercise tolerance and respiratory drive and respiratory muscle function in COPD. METHODS: 28 patients with COPD and 26 normal subjects were involved in the study. Routine pulmonary function, pulmonary diffusing capacity, P0.1, PImax were measured at rest. Oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE) etc were measured during exercise testing. Borg Scale was recorded simultaneously. Arterial blood gases were measured before and after exercise. RESULTS: (1) PImax in COPD group (40 +/- 15 mm Hg) was significantly lower than that in the normal group [(53 +/- 19) mm Hg, P < 0.05]. P0.1 in COPD group [(2.8 +/- 0.9) mm Hg] was significantly higher than that in the normal group [(2.0 +/- 0.7) mm Hg, P < 0.05]. Inspiratory drive efficacy (VT/P0.1) in COPD group [(0.21 +/- 0.04) L/mm Hg] was significantly lower than that in the normal group [(0.28 +/- 0.07) L/mm Hg, P < 0.05]. P0.1/PImax in COPD group was (0.069 +/- 0.021), significantly higher than that in the normal group [(0.037 +/- 0.009), P < 0.01]. (2) VO2max was correlated with P0.1/Pimax and Borg Scale in COPD patients (r = 0.66, P < 0.01, and r = 0.53, P < 0.05 respectively). Borg Scale was also positively correlated with P0.1/PImax in COPD group (r = 0.49, P < 0.05). CONCLUSION: In addition to airway obstruction and the damaged gas exchange, exercise intolerance in COPD may also be related to the increased respiratory drive and dysfunction of respiratory muscle.

Adult↗

PubMed2001

[Effect of platelet on procoagulant activity of monocyte].

OBJECTIVE: To investigate the effect of platelet on procoagulant activity of mononcyte(M). METHODS: The procoagulant activity of M lysates was measured by one stage clotting time assay, the tissue factor (TF) activity and the role of P-selectin were confirmed by specific monoclonal antibodies (McAb). RESULTS: 1. Activated M challenged by lipopolysaccharide(LPS) had augmented procoagulant activity and this effect was blocked by TF McAb. 2. Procoagulant activity of M and activated M increased significantly with the presence of activated platelets. 3. The enhancement effect of activated platelet on the procoagulant activity of M was blocked by P-selectin McAb. CONCLUSION: TF expression of M contributes to the procoagulant activity of Ms and activated platelet enhances the procoagulant activity via P-selectin.

Antibodies, Monoclonal↗

PubMed2001

[Characteristics and quantitative simulation of stomatal conductance of Aneurolepidium chinense].

Based on field measurements of stomatal conductance and photosynthesis of Aneurolepidium chinense, the dynamic characteristics and the relationship between stomatal conductance and environmental conditions were examined to develop a leaf stomatal conductance model for A. chinense. The results showed that the variation of stomatal conductance of A. chinense was closely correlated with environmental factors, such as physiologically active radiation (PAR), vapor pressure deficit (VPD) and air temperature (Ta). The daily variation of A. chinense stomatal conductance could be described as M-type curve at fair-weather, but [symbol: see text]-type curve at cloudy weather. The value of stomatal conductance increased with the increase of PAR or Ta, but decreased with the increase of VPD. The relationship between stomatal conductance(gs) and environmental factors could be expressed as: gs = PAR(2.01 Ta2 + 147.74 Ta2321.11)/((444.62 + PAR)(-538.04 + VPD)). This model would be helpful to simulate the dynamical photosynthesis of leaf and canopy and to further simulate the NPP of ecosystems and the exchange of water and heat among the soil-plant-atmosphere continuum.

Computer Simulation↗

PubMed2001

[Degradation of phenanthrene and pyrene in contaminated soil by immobilized Zoogloea sp. and Fusarium sp].

Immobilized with PVA, sodium alginate and activated carbon, both Zoogloea sp. and Fusarium sp. strains could degrade phenanthrene and pyrene efficiently. The optimal carrier was made of 100 rho.g-1 L PVA, 5 sodium alginate rho.g-1 L and 50 activated carbon rho.g-1 L. The degradation rates of phenanthrene and pyrene in 10 days were 87.48% and 75.34% by the immobilized bacterium, 37.04% and 20.85% higher than those by the free bacterium, and the rates in 15 days were 84.36% and 74.87% by the immobilized fungus, 5.35% and 11.23% higher than those by the free fungus.

Biodegradation, Environmental↗

PubMed2001

[Orthotopic liver transplantation: report of 70 cases].

OBJECTIVES: To summarize the results of liver transplantation for various end-stage liver diseases at Sun Yat-sen University of Medical Sciences, define the role of liver transplantation in treatment of hepatocellular carcinoma (HCC) and fulminant hepatitis B, and assess the value of lamivudine for preventing HBV recurrence. METHODS: Clinical data of seventy patients undergoing orthotopic liver transplantation (OLT) at Sun Yat-sen University of Medical Sciences between April 1993 and December 2000 were retrospectively analyzed. The main indications for liver transplantation were HCC (26 cases), liver cirrhosis (21), fulminant hepatitis B (12), sclerosing cholangitis (4) and other terminal liver diseases (7). Lamivudine was used in 12 patients with fulminant hepatitis B. Logistic multivariate regression analysis was employed to determine the risk factors predicting outcome of liver transplantation. RESULTS: Fifty-four patients survived for more than one month and 16 patients died within 30 days after OLT. The overall hospital survival rate was 77.1%. The hospital survival rates in Child's A and B patients were 87.5% and 83.3%, respectively. They were superior to those of the Child's C patients (P < 0.05). The outcome of patients with small HCC was superior to that of patients with large HCC. Preoperative APACE III scores, the severity of ascites, and serum creatine level had an independent influence on outcome. Of the patients with fulminant HBV infection, 9 survived for 2-24 months. Treatment with lamivudine monotherapy was both well tolerated and efficacious in patients with fulminant Hepatitis B. CONCLUSIONS: OLT can cure some patients and provide palliation for others with HCC. Patient selection is extremely important for predicting outcome. The results support the application of liver transplantation as a therapeutic modality for various end-stage liver diseases. Lamivudine is effective and safe in OLT for patients with HBV infection.

Adolescent↗

PubMed2001

[Use of microsatellites in zygosity diagnosis of twins].

OBJECTIVE: To diagnose zygosity of twins by microsatellite polymorphism. METHODS: One hundred and eighty-four samples, including 69 pairs of twins with the same gender and 6 pairs of twins with different gender were recruited. Seventeen sib pairs were also collected for controls. Nine highly polymorphic microsatellite loci were amplified by polymerase chain reaction (PCR) using fluorescence-labeled primers and the products were sized by automated fragment analysis after electrophoresis and laser detection. Zygosity was diagnosed by comparing the concordance of the genotype of the 9 markers. RESULTS: Sixty-three pairs of monozygotic (MZ) and 12 pairs of dizygotic (DZ) twins were assigned their zygosity by comparison of polymorphism of 9 microsatellite loci. Within each of the 63 monozygotic (MZ) pairs there was complete concordance. However, within each of the 12 dizygotic pairs and other 17 sib pairs, discordant loci were found. With five or six markers, the probability that any twin pair was MZ if all markers were concordant was 99% or 99.6%, respectively. With all the nine markers, the probability that any twin pair was MZ if all markers were concordant was 99.95%. CONCLUSION: The technology of gene scan and genotyping provides a rapid and reliable approach to zygosity detection.

DNA↗

PubMed2001

Prevention and treatment of hepatitis B relapse after liver transplantation.

OBJECTIVES: To investigate the effect of orthotopic liver transplantation (OLT) on hepatitis B(HB)-related diseases and the efficiency of prevention and treatment with lamivudine on recurrence of hepatitis B posttransplant in China. METHODS: Orthotopic liver transplantation (OLT) under veno-venous bypass was performed in 10, of whom 9 males had hepatitis B and 1 female had hepatocellular cancer (HCC) without HB pretransplant. Eight of the 9 males had fulminant hepatitis B (FHB) and they all had preoperative serious jaundice, ascites and coagulopathy. Six had encephalopathy; 1 was associated with acute renal failure, and 1 with gastrointestinal hemorrhage. Seven of the 10 patients had lamivudine to prevent reinfection with hepatitis B. RESULTS: Of the 8 patients who have survived for 2-12 months, 7 have survived for 6-12 months. Two died, one of recurrent FHB and the other from multi-organ failure (MOF). Seven preoprative HB patients of the 8 survivors have excellent liver function through 1 has positive HBsAg 6 months after OLT. One of the 8 survivors, the female with HCC pretransplant, suffered hepatitis B 6 months after OLT and her hepatic function has been gradually improving with lamivudine therapy. CONCLUSIONS: OLT is an effective therapy for certain cases of FHB and HCC and lamivudine may prevent recurrence of hepatitis B after OLT.

Adult↗

PubMed2001

Simian virus 40 large tumor antigen forms specific complexes with p53 and pRb in human brain tumors.

OBJECTIVE: To study the role of simian virus 40 (SV40) early region gene coding product large tumor antigen (Tag) expression and the interaction between Tag and tumor suppressors p53 and pRb in human brain tumorigenesis. METHODS: Tag was investigated by immunoprecipitation followed by silver staining and Western blot in 65 cases of human brain tumors and 8 cases of normal brain tissues. Tag-p53 and Tag-pRb complexes were screened in 18 and 15 Tag positive tumor tissues, respectively. RESULTS: Tag was found in all 8 ependymomas and 2 choroid plexus papillomas, 90% of pituitary adenomas (9/10), 73% of astrocytomas (11/15), 70% of meningiomas (7/10), 50% of glioblastomas multiforme (4/8), 33% of medulloblastomas (2/6). 5 oligodendrogliomas, 1 pineocytoma, and 8 normal brain tissues were negative for Tag. Tag-p53 complex was detected in all 18 Tag positive tumors. Tag-pRb complex was found in all 15 Tag positive tumors. CONCLUSION: SV40 Tag is expressed in human brain tumors and can form specific complexes with tumor suppressors p53 and pRb. The inactivation of p53 and pRb due to the formation of Tag-p53 and Tag-pRb complexes may be an important mechanism in the etiopathogenesis of human brain tumors.

Animals↗

PubMed2001

[Clinical study of topotecan in the treatment of small cell lung cancer and recurrent ovarian cancer].

OBJECTIVE: To evaluate the effect and adverse reaction of China made topotecan in the treatment of small-cell lung cancer (ACLC) and recurrent ovarian cancer (OV). METHODS: From January to July, 2000, topotecan was used to treat 141 patients at a dose of 1.2 mg/m2, given daily as 30-min i.v. infusion for 5 days. Treatment was repeated once every 3 weeks. Of the 141 patients, 118 were evaluable for therapeutic efficacy. All the patients received a total of 286 cycles of treatment were assessable for analysis of adverse reactions. RESULTS: Among the evaluable patients, there were 5 CR, 35 PR, with an overall response rate (RR) of 33.8%. There were 3 CR and 26 PR in 89 patients with SCLC (RR 32.5%). The response rate of patients with or without prior chemotherapy was 15.6% and 50%, respectively. In 29 patients with recurrent OV, there were 2 CR and 9 PR (RR 37.9%). The major toxic effect was myelosuppression. Non-hematopoietic toxicities were mild and tolerable. CONCLUSION: Topotecan is an effective drug for the treatment of SCLC and recurrent OV. It is still efficacious in some patients who previously received standard chemotherapy. The major dose-limiting toxicity is myelosuppression. The response rate and toxicity of the domestically made topotecan are comparable with those of the imported one.

Adolescent↗

PubMed2001

[A contour map segmentation for laser scanning confocal microscopic biomedical images].

We propose a contour map segmentation method for laser scanning confocal microscopic (LSCM) biomedical images. In this method, an image is first segmented into sub-regions by contour map. Then the sub-regions are merged from top to bottom or from bottom to top, according to a segmentation criterion of intensity homogeneity. The merging procedures continue until no region needs to be merged. The advantage of this method is that the objects with wide intensity ranges and different intensity homogeneity can be segmented properly. In this paper, the region segmentation by contour map is first addressed. Next a region merging according to a segmentation criterion of intensity homogeneity is presented, and then the design of a linear intensity homogeneity segmentation criterion is introduced. Two examples of image segmentation by this method are given at the end of this paper.

Algorithms↗

PubMed2001

Early diagnosis and monitoring of active HCMV infection in children with systemic lupus erythematosus.

OBJECTIVE: To investigate the prevalence and features of active human cytomegalovirus (HCMV) infection in children with systemic lupus erythematosus (SLE) and evaluate the diagnostic value of the HCMV using antigenemia assay, serum polymerase chain reaction (PCR) and serology test. METHODS: Twenty-one SLE children undergoing immunosuppressive therapy were enrolled in this study. Immunofluorescence assay, PCR and serology tests were used to determine HCMV pp65 and p72 antigens in leukocytes, HCMV DNA in sera, and HCMV specific IgM and IgG antibodies, respectively. As a control group, twenty-one immunocompetent children with skeletal malformation were involved in this study. Statistical analysis was performed using Chi-square test or Fisher's exact test (Systat, USA), P values less than 0.05 were considered significant. RESULTS: Active HCMV infection was diagnosed in 28.6% (6/21) of SLE patients, with none in the control group; the difference between the two groups was significant (P = 0.027). Two out of 6 SLE patients developed active HCMV infection before immunosuppressive therapy and the remaining 4 patients developed SLE after immunosuppressive therapy. Among the 21 SLE children, HCMV pp65 antigenemia was detected in 5 patients, p72 antigenemia in 3 patients, serum HCMV DNA in 9 patients, serum HCMV-specific IgM in 2 patients, and IgG in 19 patients. The sensitivity and specificity for diagnosis of active HCMV infection were 83.3% and 100%, respectively for pp65 antigenemia; 50% and 100% for p72 antigenemia; 100% and 80% for serum PCR; 33.3% and 100% for HCMV IgM serology; 50% and 100% for HCMV IgG serology. CONCLUSIONS: Compared with the control group, active HCMV infection is much more frequent in SLE children, and can occur before treatment with immunosuppressive agents, but most often occur after immunosuppressive therapy. In comparison with the other techniques used in this study, the pp65 antigenemia assay seems to be a better method for the early diagnosis and monitoring of active HCMV infection in children with SLE.

Adolescent↗

PubMed2001

[Study on the protective effect of xinkang oral liquid on the isoproterenol-induced ischemic myocardial damage in rats].

OBJECTIVE: To study the protective effect of Xinkang oral liquid on the ischemic myocardial damage. METHODS: Ischemic myocardial damage model was obtained by i.p. 85 mg/kg isoproterenol. The level of superoxide dismutase (SOD), malondialdehyde (MDA), creatine kinase (CK), lactic dehydrogenase (LDH) in the serum and endothelin (ET) in the plasma were detected. RESULTS: The level of ET, MDA, CK, LDH of Xinkang oral liquid group was much lower than that of model group (P < 0.01). The SOD activity was higher than that of model group (P < 0.01). The level of Xinkang oral liquid group was lower than that of Shuxin oral liquid group. The SOD activity of Xinkang oral liquid group was much higher than that of Shuxin oral liquid group (P < 0.01). CONCLUSION: Xinkang oral liquid can prevent the myocardium from ischemic damage.

Animals↗

PubMed2001

[Dexamethasone inhibits trabecular meshwork cell growth and epidermal growth factor mRNA expression in vitro].

OBJECTIVE: To investigate the effect of dexamethasone on cultured trabecular meshwork cell growth and the cell expression of epidermal growth factor (EGF) mRNA in vitro. METHODS: Human trabecular meshwork cells were cultured in vitro. The third passage cells were used in this experiment; with the addition of 300 microgram/ml dexamethasone in the culture medium in the test group, the culture was carried out as routine. After 5 days, the cell growth conditions were observed. After 7 days, the cells in the test and the control group were collected, and mRNA was drawn from them in both groups. EGFcDNA probe with alpha-(32)P isotope labeling was used to proceed dot blot hybridization and autoradiography to detect EGFmRNA of the cells. A computerized laser instrument was used to scan the size of dot blot hybridization, the relative value of the optical density was measured in the autoradiographs, and the inter-group comparison was made. RESULTS: Trabecular meshwork cells were inhibited by dexamethasone in the test group. The cells in the control group had been confluent at the 5th day, but the cells in the test group still grew like tribes. The total RNA was 14 microgram in the test group, while 22.5 microgram in the control group. In both groups, 14 microgram RNA was used for dot blot hybridization test with EGFcDNA probe. Autoradiographic image was positive in the two groups. The results of the scanning and the measurement of the autoradiograph density showed that dexamethasone obviously decreased the EGFmRNA expression of trabecular meshwork cells. CONCLUSIONS: Dexamethasone can inhibit trabecular meshwork cell growth in vitro. At first it affects the cell total RNA transcription and the second affects the EGFmRMA expression. It is suggested that steroid glaucoma be caused by the inhibition of various physiological and metabolic functions of trabecular meshwork cells induced by dexamethasone.

Adult↗