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Biomedical subjects

Hong Liu

Publications and source records attributed to Hong Liu.

At least 343 records · Page 19Linked to original sources
PubMed2003

[Alteration of homocysteine before and after hemodialysis in chronic hemodialysis patients].

OBJECTIVE: To determine the plasma hemocysteine (Hcy) concentration in chronic hemodialysis patients and controls, and the relation between chronic hemodialysis and the plasma total Hcy level in chronic hemodialysis patients. METHODS: Using HPLC-FLD method, the plasma total Hcy concentration was determined in 11 patients with chronic hemodialysis and 30 healthy volunteers. RESULTS: The plasma total Hcy level in chronic hemodialysis was significantly higher than that in the controls (13.54 +/- 4.49 mumol/L) (P < 0.01). The plasma total Hcy level after the hemodialysis (21.30 +/- 10.81 mumol/L) was lower than before the hemodialysis (29.53 +/- 13.59 mumol/L) (P < 0.01). CONCLUSION: The plasma total Hcy level in chronic hemodialysis patients was higher than that in the controls. Hemodialysis can clean the plasma Hcy in chronic hemodialysis patients, but it can not decrease it to the normal level.

Adolescent↗
PubMed2003

[The clinical features of severe aplastic anemia patients with complication of infection].

OBJECTIVE: To study the clinical features of severe aplastic anemia (SAA) patients with complication of infection. METHODS: A retrospective analysis of prevalence of infection occurring in 229 SAA patients, their bacterial spectrum, and the effect of GM-CSF or G-CSF on the infection were done. RESULT: The prevalence of infection in SAA patients was 86.0%, among which 54.2% was infected with gram-positive organisms, 40.0% with gram-negative bacilli and 5.8% with fungal infections. Septicemia occurred mostly with E. coli and Pseudomonas infection. Patient's neutropenia was significantly related to the infection. The patients with neutrophil count less than 0.2 x 10(9)/L had more frequent and severe infection. Age, hemoglobin level, subtype of T lymphocytes and antithymocyte globulin therapy were not related to infection. Prophylaxis usage of floxacin could not reduce patient' gastrointestinal infection. The total mortality of SAA patients with infection was 23.1%. Pulmonary infection and septicemia increased mortality, and GM-CSF/G-CSF therapy reduce mortality. CONCLUSION: SAA patients were at high risk of infection which was significantly associated with severe neutropenia. GM-CSF or G-CSF therapy exerts an assistant role to antibiotics in controlling the infections.

Adolescent↗
PubMed2003

[An analysis of relapse and risk factors of autoimmune hemolytic anemia and Evans syndrome].

OBJECTIVE: To analyse the relapse rate and risk factors of autoimmune hemolytic anemia (AIHA) and Evans syndrome. METHODS: Fifty two cases of AIHA and Evans syndrome in remission being followed up for 1 - 14 years (median time 3.8 years) were analysed for relapse rate. The risk factors of relapse were analysed by case-control study. RESULTS: The total relapse rate of these AIHA and Evans syndrome patients was 57.7%, and the median remission duration to the first relapse was 9 months. The relapse rates in patients with negative Coombs test, warm autoantibodies and both of warm and cold autoantibodies were 30.8% (4/13), 54.0% (13/24) and 86.7% (13/15), respectively. The relapse rate in patients with cold antibody was the highest (P < 0.05). The relapse rate in patients with antibody titer >or= 100 was 92.9% (13/14) and was higher than that in patients with antibody titer < 100 [59.5% (13/22)] (P < 0.05). Patients treated with prednisone and cyclosporin relapsed less than those treated with prednisone alone, and the relapse was related to the therapy course of prednisone and CsA. CONCLUSION: Because of the high relapse rate, AIHA and Evans syndrome should be treated according to the class of autoantibodies, and with longer course of prednisone and cyclosporin and prophylaxis of infection.

Adolescent↗
PubMed2003

[Study on effects of Erigeron breviscapus extract on anticoagulation].

OBJECTIVE: To study the effect of Erigeron breviscapus extract on anticoagulation. METHOD: Coagulation time (CT), prothrombin time (PT), platelet factor III (PF3) and euglobulin lysis time (ELT) have been used to evaluate the anticoagulation activities of Erigeron breviscapus extract. RESULT: Erigeron breviscapus extract significantly delayed CT and PT, inhibited the activity of PF3, and decreased ELT. CONCLUSION: Erigeron breviscapus extract plays an role in anticoagulation by inhibiting PF3 and prothrombin V. It can also enhance the activity of fibrimolysis.

Animals↗
PubMed2003

[Detection for endogenous erythroid colony in the patients with polycythemia vera and its clinical significance].

OBJECTIVE: To investigate the growth of endogenous erythroid colony (EEC) in polycythemia vera (PV) patients and its clinical significance. METHODS: Bone marrow mononuclear cells of 26 PV patients, 2 secondary erythrocytosis (SE) and 19 normal controls were cultured by Marsh's method for EEC. RESULTS: 1. EEC was present in 25/26 (96.2%) PV patients and was not found in 2 SE patients and 19 normal controls. 2. The number of EEC and the ratio of EEC/Epo-dependent CFU-E (EEC ratio) were positively correlated with the hemoglobin (Hb) levels (r = 0.608, P = 0.01) in PV patients, but did not correlate with white blood cell (WBC) counts, platelet counts and neutrophil alkaline phosphatase scores. 3. EEC did not correlate with PV patients' serum Epo levels (r = 0.518, P = 0.125). 4. Fifteen PV patients were treated with hydroxyurea and/or interferon-alpha. Their EEC ratio before treatment was correlated positively with the time required for complete remission (CR) (r = 0.651, P = 0.009) and negatively with the time before relapsing (r = -0.529, P < 0.02). 5. EECs of 7 PV patients treated with HU/IFN were decreased after their blood cell counts normalization. 6. There was a positive correlation between the EEC ratio and the attacks of vascular thrombosis (r = 0.524, P = 0.01). (7) The apoptosis of bone marrow mononuclear cells of PV patients was less than that of normal controls. PV patients' EEC was negatively correlated with the apoptosis of their bone marrow mononuclear cells (r = -0.192, P < 0.045). CONCLUSION: EEC is peculiarly present in PV patients, and is a sensitive parameter in reflecting the abnormal hematopoietic clone burden and in diagnosing and monitoring the disease.

Adult↗
PubMed2003

[Principles and experimental analysis of a measuring system for measuring spacesuit joint's damping parameters].

OBJECTIVE: To measure the damping parameters of the spacesuit joint. METHOD: The principles of the passive robot system for measuring spacesuit joint's damping parameters were presented. Basing on its special mechanical structure, a 3 DOF model of the flexible IVA (intra-vehicular activity) spacesuit's sleeve was built. The optimal approximation of inverse calculation based on 6 dimension space interval was described. The damping parameters of an actual IVA spacesuit's sleeve were measured on the actual testbed. Also, the potential application of the measuring system was discussed. RESULT: The model of spacesuit sleeve and the forward/inverse kinematics were proved by experimental measurements and real time 3D simulation. CONCLUSION: The principles and the proposed method of the measurement were testified.

Computer Simulation↗
PubMed2003

[Experimental study of the specific immunoresponse induced by p53 modified dendritic cells].

OBJECTIVE: To explore the specific cytotoxic T lymphocyte (CTL) induced by dendritic cells (DC), which were transfected by the plasmid pC53-SN3 encoding p53 gene. METHODS: DC derived from HLA-A2(+) mononuclear cells of the 24-lung cancer patients was transfected with the plasmid pC53-SN3 by lipofectamine and then co-cultured with auto-unpurified T cells to induce potent CTL (T-pC53-SN3). The cytolysis of specific CTL against Calu-6, a HLA-A2(+) human lung cancer cell line, was measured by using lactate dehydrogenase (LDH) releasing assay. RESULTS: The expression of CD(1a) and CD(83), the correlative markers of DC, increased apparently after transfected with plasmid pC53-SN3, the expression rate was (5.45 +/- 0.89)% and (3.26 +/- 0.47)% versus (52.15 +/- 11.56)% and (25.78 +/- 12.35)%. CD(14) decreased apparently, but other DC correlative markers of CD(1a), CD(40), CD(86), and HLA-DR remained almost the same as that before transfection. Compared with T-IL-2, the CTL derived from PBMNC stimulated by IL-2 (100 U/ml), the cytolytic activity of T-pC53-SN3 against Calu-6 cell line showed a significant increase, but cytolytic activity was 56.79 +/- 15.67 and 39.33 +/- 9.88, respectively, when effect cells: target cells was 10:1. The expression of the CD(8), CD(69), and CD(45)RO/CD(8) of T-pC53-SN3 cells increased significantly, but that of CD(3), CD(4), CD(86), ect, was not significantly different from those of T-pCMV-neo. CONCLUSIONS: It showed that DC transfected by p53 gene could induce potent HLA-A(2) restrictive CTL to kill tumor cell efficiently.

Antigens, CD↗
PubMed2003

[Analysis of serological findings and clinical manifestations of TORCH infections in newborns].

BACKGROUND: To search for the serological findings and early clinical manifestations as evidences for prevention and treatment TORCH infections in pregnant women and newborns as early as possible. METHODS: ELASA was performed to screen specific anti-TORCH (Toxoplasma gondii, Cytomegalovirus, Rubella virus, Herpes simplex virus) Ig-M antibodies. RESULTS: Totally 1,554 in-patients who were treated in Neonatal Intensive Care Unit (NICU) of our hospital from January 2000 to January 2003 were retrospectively studied, 48 of them had TORCH infections. Cytomegalovirus (CMV), rubella and herpes simplex virus infections accounted for 52.1%, 33.3% and 14.6%, respectively. None of them had toxoplasma infection. CONCLUSION: TORCH infections can cause multiorgan lesions, such as hearing impairment, hyperbilirubinemias and liver dysfunction, impairment of neurologic system, myocardial impairment, thrombocytopenia, and congenital heart disease.Rubella vaccine inoculation, serological screening during pregnancy and early period of newborn, intervention and treatment in the early period are most important.

Antibodies, Viral↗
PubMed2003

[Etiologic analysis of 1137 inpatients of chronic renal failure].

OBJECTIVE: To investigate the main causes of chronic renal failure (CRF) and the differences in how subpopulation is affected by these causes, and to determine the morbidity of anemia and hypertension, and the relation between age and gender in CRF patients. METHODS: We chose 1137 inpatients diagnosed as CRF in the Department of Nephropathy of 2nd Xiangya Hospital of Center South University from January 1996 to March 2002. We collected the information on name, gender, age, admission number, diagnosis, blood pressure, blood routine, renal function, and creatinine clearance rate. RESULTS: Chronic glomerulonephitied accounted for 56.4% as the leading cause, followed by hypertensive nephropathy (14.3%), obstructive nephropathy (7.2%), and diabetic nephropath (6.7%). Gender influenced the incidence of some diseases. Most patients were companied with anemia (90.7%) and hypertension (72.6%). CONCLUSION: The main causes of CRF include chronic glomerulonephitis, hypertensive nephropathy, obstructive nephropathy, and diabetic nephropath.

Adolescent↗
PubMed2003

[Collagen membrane as scaffold for the three-dimensional cultivation of cardiac cells in vitro].

The objective of this study was to develop research of cardiac cells to reestablish 3D tissue architecture in vitro, we performed studies using collagen membrane as three-dimensional scaffold for cardiac cells culture with the principles and methods of tissue engineering. The polymer scaffold provides a 3-D substrate for cell attachment and tissue formation. Cardiac cells isolated by enzymatic digestion from 1d old neonatal rats were seeded to three-dimensional collagen scaffolds and tissue culture plates. The morphology, beating rate and the metabolic indexes, including specific consumption rate of glucose (q(glu)) , specific production rate of lactate (q(lac)), lactate transform rate ( Y(lac/glu)), specific creatine kinase (CK) and lactate dehydrogenase (LDH) activities of cardiac cells cultured on three-dimensional collagen membrane and tissue culture plates were compared. It was found that cells shape and cells' CK and LDH activity was no differences between 3D and 2D cultures and cell beat rate on cell culture cluster was slower than those cells cultured on collagen membrane, However the cell glucose consumption and lactate yield rate of cells cultured on cluster was higher than those cells cultured on collagen membrane. After 5 days of cultivation, cardiac cells cultured on collagen membrane scaffolds organized into three-dimensional (3D) aggregates as opposed to the two-dimensional (2D) aggregates mosaic pattern seen in tissue culture plates, and spontaneous and rhythmical contractile 3D cultures in unison were visible to the naked eye and the area of synchronous contract three-dimensional (3D) aggregates reaches 80cm2. The mean value of q(glu), q(lac) and Y(lac/glu) of cultured on three-dimensional collagen scaffold was 7.37 micromol/10(6) cells/d, 2.92 micromol/10(6) cells/ d and 0.38 micromol/micromol, versus 7.59 micromol/10(6)cells/d, 3.83 micromol/10(6) cells/d and 0.51 micromol/micromol in tissue culture plates. These results demonstrate that cardiac cells immobilized on collagen membrane in 3D cultures maintain similar metabolic activity and contractile function when compared with native cardiac cells. The above results support the idea that engineered cardiac tissue can be used as a model of native tissue for studies of tissue development and function in vitro and eventually for tissue repair in vivo.

Animals↗
PubMed2003

[The construction and expression of superantigen SEA and antimelanoma ScFv fusion gene].

Two strategies, direct ligation after enzyme digestion and over-lap PCR technology, were adopted to construct a fusion gene which was composed of the antimelanoma single chain antibody gene and the staphylococcal enterotoxin A gene without N-terminal signal sequence. The fusion gene was subcloned into pET28-a vector and transformed into E. coli BL21(DE3). Ni-NTA system was selected to separate and purify the expresstd products. The inhibition ratio of the fusion protein was tested by MTT method. It is shown that the 6His-ScFv-SEA fusion protein can be expressed stably in E. coli BL21 (DE3). The quantity of the fusion protein was shown up to 30% of the total protein of the bacteria and mainly in inclusion body. By activation the effective cells, the fution protein can inhibit the melanoma cell whith expressed corresponding antigen.

Cell Line, Tumor↗
PubMed2003

[Study on the properties of methyl parathion hydrolase from Pseudomonas sp. WBC-3].

A methyl parathion degradation enzyme, or methyl parathion hydrolase (MPH, EC 3.1.8.1), locating in the soluble intracellular fraction of Pseudomonas sp. WBC-3, was purified 49.1-fold to homogeneity by one-step ion exchange chromatography. The physical and chemical properties of the purified MPH were studied. The purified MPH displayed relatively broad optimal temperature around 40 degrees. The activity of MPH was affected by pH and the optimal pH was 11.0. Cd2+ and Fe2+ could enhance the catalytic efficiency of MPH while Hg2+, Zn2+, Al3+ and Bi3+ showed inhibition effect. With methyl parathion as the optimal substrate, the Km was 0.0807mmol/L and the kcat was 2.1 x 10(6) min(-1). In addition, the comparison of native and subunit molecular weights of MPH suggested that this enzyme was a monomer of approximate 34kD.

Enzyme Stability↗
PubMed2002

Characterization of electrostatic binding sites of extracellular polymers by linear programming analysis of titration data.

Electrostatic binding sites of extracellular polymeric substances (EPS) were characterized from titration data using linear programming analysis. Test results for three synthetic solutions of given solutes comprising amino, carboxyl, and phenolic groups indicated that this method was able to identify the electrostatic binding sites. For the six sites with pK(a) between 3 and 10, the estimated pK(a) deviated 0.11 +/- 0.09 from the theoretical values, and the estimated concentrations deviated 3.0% +/- 0.9% from the actual concentrations. Two EPS samples were then extracted from a hydrogen-producing sludge (HPS) and a sulfate-reducing biofilm (SRB). Analysis of charge excess data in titration from pH 3 to 11 indicated that the EPS of HPS comprised of five electrostatic binding sites with pK(a) ranging from 3 to 11. The pK(a) values of these binding sites and the possible corresponding functional groups were pK(a) 4.8 (carboxyl), pK(a) 6.0 (carboxyl/phosphoric), pK(a) 7.0 (phosphoric), pK(a) 9.8 (amine/phenolic), and pK(a) 11.0 (hydroxyl). EPS of the SRB comprised five of similar binding sites (with corresponding pK(a) values of 4.4, 6.0, 7.4, 9.4, and 11.0), plus one extra site at pK(a) 8.2, which was likely corresponding to the sulfhydryl group. The total electrostatic binding site concentration of EPS extracted from HPS were 10.88 mmol/g-EPS, of which the highest concentration was from the site of pK(a) 11.0. The corresponding values for the EPS extracted from SRB were 16.44 mmol/g-EPS and pK(a) 4.4. The total concentrations of electrostatic binding sites found in this study were 20- to 30-fold of those reported for bacterial cell surface, implying that EPS might be more crucial in biosorption of metals than bacterial cell surface in wastewater treatment and in bioremediation.

Bacteria↗
PubMed2002

Modulation of estrogen receptor alpha function and stability by tamoxifen and a critical amino acid (Asp-538) in helix 12.

Estrogen receptor alpha (ER) is a ligand-activated transcription factor implicated in breast cancer growth. Selective estrogen receptor modulators (SERMs), such as tamoxifen (4-OHT), bind to the ER and affect the position of helix 12, thereby influencing coregulator binding and ER transcriptional activation. Previous studies have shown that a triple mutation in helix 12 (3m; D538A/E542A/D545A) caused a change in ER stability and obliterated 4-OHT action (Liu, H., Lee, E. S., de los Reyes, A., Zapf, J. W., and Jordan, V. C. (2001) Cancer Res. 61, 3632-3639). Two approaches were taken to determine the role of individual mutants (D538A, L540Q, E542A, and D545A) on the activity and stability of the 4-OHT.ER complex. First, mutants were evaluated using transient transfection into ER-negative T47D:C4:2 cells with an ERE3-luciferase reporter, and second, transforming growth factor alpha (TGFalpha) mRNA was used as a gene target in situ for stable transfectants of MDA-MB-231 cells. Transcriptional activity occurred in the presence of estrogen in all of the mutants, although a decreased response was observed in the L540Q, 3m, and D538A cells. The 3m and D538A mutants lacked any estrogenic responsiveness to 4-OHT, whereas the other mutations retained estrogen-like activity with 4-OHT. Unlike the other mutants, the ER was degraded in the D538A mutant with 4-OHT treatment. However, increasing the protein levels of the mutant with the proteasome inhibitor MG132 did not restore the ability of 4-OHT to induce TGFalpha mRNA. We suggest that Asp-538 is a critical amino acid in helix 12 that not only reduces the estrogen-like actions of 4-OHT but also facilitates the degradation of the 4-OHT.D538A complex. These data further illustrate the complex role of specific surface amino acids in the modulation of the concentration and the estrogenicity of the 4-OHT.ER complex.

Aspartic Acid↗
PubMed2002

Department of Defense Era of Hope meeting, Orlando, Florida, USA, 25-28 September 2002.

The Era of Hope meeting addressed with a multidisciplinary approach the most critical issues in breast carcinogenesis. The issues that we summarize here include: a) the use of rodent models for the study of mammary gland development and breast tumorigenesis; b) the effects of stroma on mammary epithelial differentiation and malignant transformation; c) a further characterization of the interactions between steroid and growth factor receptors; d) the improvement of technologies for early detection of breast tumors and the establishment of their progression; and e) the development of vaccines as potential new therapies against specific tumor markers.

Breast↗
PubMed2002

[Comparative study of three kinds of outflow tract reconstruction of hepatic veins in piggyback liver transplantation].

OBJECTIVE: To study the effects of 3 different operational patterns of piggyback liver transplantation (PBLT) used to reconstruct backflow of hepatic veins. METHODS: Sixty-three operations of PBLT were performed on 59 patients with terminal hepatic diseases after three operational patterns: EEAT [the suprahepatic inferior vena cava (sup-H-IVC) of donor is anstomosed with the plasticized hepatic vein of recipient end-to-end, also called standard PBLT, SPBLT] in 17 cases, ESAT (the sup-H-IVC of donor is anastomosed with the sup-H-IVC of recipient end-to-side) in 12 cases, and SSAT [the retrohepatic IVC (RHIVC) of donor is anastomosed with the RHIVC of recipient side-to-side] in 32 cases, the latter two patterns being called ameliorative PBLT (APBLT) jointly. The effects were analyzed. RESULTS: Complications, such as backflow obstruction of hepatic vein and delayed recovery of liver function, were observed in the EEAT and ESAT groups, but not in the SSAT group. CONCLUSION: The SSAT pattern of PBLT is easy to perform and advantageous to avoid the technical maladies of the other 2 patterns and postoperative complications, and provides assurance of recovery after operation.

Adolescent↗
PubMed2002

Inhibitory mode of 1,5-diarylpyrazole derivatives against cyclooxygenase-2 and cyclooxygenase-1: molecular docking and 3D QSAR analyses.

The Lamarckian genetic algorithm of AutoDock 3.0 has been employed to dock 40 1,5-diarylpyrazole class compounds into the active sites of cyclooxygenase-2 (COX-2) and cyclooxygenase-1 (COX-1). The binding models were demonstrated in the aspects of inhibitor's conformation, subsite interaction, and hydrogen bonding. The data of geometrical parameters and RMSD values compared with the known inhibitor, SC-558 (43), show that these inhibitors interact respectively with COX-2 and COX-1 in a very similar way. The r(2) values of 0.648 for COX-2 and 0.752 for COX-1 indicate that the calculated binding free energies correlate well with the inhibitory activities. The structural and energetic differences in inhibitory potencies of 1,5-diarylpyrazoles were reasonably explored, and the COX-2/COX-1 selectivity was demonstrated by the three-dimensional (3D) interaction models of inhibitors complexing with these two enzymes. Using the binding conformations of 1,5-diarylpyrazoles, consistent and highly predictive 3D quantitative structure-activity relationship (QSAR) models were developed by performing comparative molecular field analyses (CoMFA) and comparative molecular similarity analyses (CoMSIA). The q(2) values are 0.635 and 0.641 for CoMFA and CoMSIA models, respectively. The predictive ability of these models was validated by SC-558 (43) and a set of 10 other compounds that were not included in the training set. Mapping these models back to the topology of the active site of COX-2 leads to a better understanding of vital diarylpyrazole compounds and COX-2 interactions. Structure-based investigations and the final 3D QSAR results provided possible guidelines and accurate activity predictions for novel inhibitor design.

Algorithms↗