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Biomedical subjects

H Chen

Publications and source records attributed to H Chen.

At least 325 records · Page 18Linked to original sources
PubMed2001

[Effects of Streptococcus sanguis on blood composition, blood pressure and cardiac dysfunction in rabbis].

OBJECTIVE: To investigate effect of streptococcus sanguis on blood cell and cardiopulmonary changes. METHODS: 133-79 strains of streptococcus sanguis (aggregation positive) were infused intravenously into rabbits. Before and 5, 10, 20, 30, 45, 60 min after infuse platelets count, leukocytes count, blood pressure and ECG were measured. RESULTS: After infused intravenously, both platelets and leukocytes count decreased remarkably (P < 0.01, n = 12). The ECG showed ST segment depression (> 0.06 mV). Diphasic blood pressure occurred (first hypertensive then hypotensive). CONCLUSIONS: Streptococcus sanguis 133-79 strains in circulation system might cause myocardia ischemia, blood pressure changes, peripheral circulation platelets and leukocytes decrease remarkably.

Animals↗
PubMed2001

[Analysis of loss of heterozygosity on 19p in primary gastric cancer].

OBJECTIVE: To investigate the loss of heterozygosity (LOH) frequency of microsatellite loci in primary gastric cancer samples and locate the deleted regions on 19p in which might exist human gastric cancer related genes. METHODS: The LOH of microsatellite loci on chromosome 19p was analyzed using PCR-SSLP-silver stain method in 43 primary gastric cancers and their paired normal tissues. RESULTS: In 43 primary gastric tumors, LOH was detected on the site for D19S424(29.63%), D19S216(11.53%), D19S406 (33.33%), D19S413(8.57%), D19S221(13.15%), D19S226(8.00%), D19S411(6.45%), D19S883(6.89%), and D19S886(10.71%), microsatellite instability (MSI) was found at the same time at locus D19S886 (17.85%). CONCLUSION: The most common LOH occurrence at D19S406 and D19S424 might imply the existence of the potential genes related to the tumorigenesis of gastric cancer in these loci.

Chromosome Mapping↗
PubMed2001

[The postburn changes of the plasma levels of PGE2 and TNF alpha in burn patients].

OBJECTIVE: To explore the postburn changes of the plasma levels of PGE2 and TNF alpha and their relationship with burn severity and sepsis. METHODS: Twenty-four burn patients were enrolled in the study and were randomly divided into four groups based on burn area and sepsis in reference to normal group (10 healthy adult volunteers). The plasma levels of PGE2 and TNF alpha at different postburn time points in all burn patients and in healthy volunteers were determined by radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: The postburn plasma PGE2 level increased in most patients but decreased in the patients with major burn or sepsis, even to the level lower than that in normal control. On the other hand, the postburn plasma TNF alpha level increased in all patients, especially obvious in those with sepsis. And the changes were not correlated to burn area and postburn time. Moreover, the postburn plasma TNF alpha level was negatively correlated to that of PGE2. CONCLUSION: Decreased postburn plasma PGE2 level was correlated to high incidence of burn sepsis. And PGE2 might down-regulate TNF alpha production.

Adolescent↗
PubMed2001

ATP sensitive K+ channel may be involved in the protective effects of preconditioning in isolated guinea pig cardiomyocytes.

OBJECTIVE: To develop a cellular model of preconditioning by a brief period of hypoxia in isolated guinea pig cardiomyocytes and to determine whether or not an ATP sensitive K+ (KATP) channel is involved in ischemic preconditioning. METHODS: Single myocytes were isolated from the ventricle of adult guinea pigs. The experimental chamber allowed the cells to be exposed to low O2 pressure. During hypoxic preconditioning, the cells were equilibrated with normaxic solution for 10 minutes and then exposed to hypoxia for 5 minutes, followed by 10 minutes of reoxygenation. The cells were then subjected to 20-180 minutes of hypoxia and reoxygenation. Ionic currents were studied with the patch clamp technique in whole-cell and cell-attached configurations. RESULTS: A 5-minute hypoxic preconditioning offered a significant protection from cell injury in subsequent hypoxia-reoxygenation. After a latency of more than 15 minutes, hypoxia induced a time-independent outward K+ current which could be blocked by 5 mumol/L glibenclamide. At 10 mV, the current increased from 78 +/- 15 pA to 1581 +/- 153 pA (P < 0.01, n = 18). However, the latency to develop KATP channel currents (IKATP) was greatly shortened in preconditioned cells, and the current was increased acceleratively. At 10 mV, the current more than 4 nA was recorded in preconditioning cells. In the single channel recordings, the time interval from the first channel opening to maximum opening was also markedly abbreviated in preconditioned cells. CONCLUSION: Isolated guinea pig cardiomyocytes can be preconditioned with a brief period of hypoxia. This hypoxic preconditioning may modify the KATP channel, and make the channel open more readily during the second hypoxia.

Adenosine Triphosphate↗
PubMed2001

Low incidence of severe aGVHD and accelerating hemopoietic reconstitution in allo-BMT using lenograstim stimulated BM cells.

OBJECTIVES: To investigate the efficacy of accelerating hemopoietic reconstraction and reducing a graft versus host disease (GVHD) in Allo-BMT receiving lenograstim stimulated donor marrow and to assess the preliminary biological mechanism. METHODS: The donors for thirty patients (study group) with leukemia were given lenograstim 3-4 micrograms.kg-1.d-1 for seven days prior to marrow harvest. The results of subsequent engraftment in the recipients was compared with fifteen donors without G-CSF (control group). Five donors themselves were studied to assess the effects of lenograstion on hematopoietic progenitor cells and lymphocyte subsets in BM. RESULTS: The stimulated bone marrow contained a higher number of nucleated cells, CFU-GM and CD34+ cells (P < 0.01). The hematopoetic reconstitution was accelerated. Until granulocyte counts exceeded 0.5 x 10(9)/L and plalete counts exceeded 20 x 10(9)/L, the days were 16.7 +/- 3.2 and 18.4 +/- 3.0 days as compared with those of the control group (22.5 +/- 5.1 and 26.3 +/- 5.9 days respectively, P < 0.01). The incidence of grade II-IV aGVHD was very low, only one case with grade II aGVHD on the skin in the study group. Four out of fifteen patients (26.7%) in the control group had grade II-IV aGVHD (P < 0.05). The number of T lymphocyte subsets in the harvested BM stimulated by G-CSF changed. In comparison with the control group, CD4+ decreased and CD8+ increased significantly (P < 0.01). The changes of progenitor cells and T lymphocyte subsets in BM from pre- to post-G-CSF stimulation indicated that the percentage of CD4+ cells reduced (P < 0.05), that of CD8+ cells, and that of CD34+ increased (P < 0.01). The incidence of chronic GVHD and relapse of leukemia were not different significantly between both groups. CONCLUSIONS: Allogenic bone marrow transplant (Allo-BMT) donors given G-CSF can accelerate engraftment and minimize the incidence of severe aGVHD. There is a trend in favour of improved transplant-related complications.

Acute Disease↗
PubMed2001

Eldepryl prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced nigral neuronal apoptosis in mice.

OBJECTIVE: To study the apoptotic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the nigral dopaminergic neurons of mice and 1-methyl-4-phenylpyridium ion (MPP+) on pheochromocytoma (PC12) cells, as well as the antagonism of Eldepryl against MPTP's apoptotic effect. METHODS: Three groups of C57BL mice were treated with MPTP, Eldepryl plus MPTP and normal saline, respectively, for 7 days before performing TUNEL (terminal deoxyneucleotidyl transferase-mediated dUTP-x nick end labeling) and FACS (fluorescence activated cell sorting) analyses of neuronal apoptosis in the substantia nigra. The same tests were employed in cell culture to examine apoptosis in PC12 cells treated with MPP+, MPTP or PBS. RESULTS: Intraperitoneal administration of MPTP 30 mg/kg could induce nigral apoptosis, and oral use of Eldepryl prior to MPTP treatment could completely prevent the nigral apoptosis caused by MPTP. MPP+, an intermediate metabolite of MPTP, could lead to the apoptosis of PC12 cells, whereas MPTP itself had no such effect on PC12 cells. CONCLUSIONS: The experiment indicated that the neurotoxin, MPTP, might cause the death of nigral neurons through a mechanism of apoptosis and this effect might be mediated by its bioactive intermediate metabolite MPP+. Eldepryl could protect the neurotoxicity from MPTP.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2001

Growth inhibition of interleukin-2 receptor gene-transduced peripheral blood lymphocytes on human ovarian cancer cells.

OBJECTIVE: To investigate the growth inhibition of interleukin-2 receptor (IL-2R) gene-transduced peripheral blood lymphocytes (PBLs) on human ovarian cancer cells. METHODS: Interleukin-2 (IL-2) and IL-2R genes were transfected into human ovarian cancer cell line 3AO and PBLs, respectively, using the same Fugene vector. Twenty-four hours later transfected and nontransfected PBLs were cocultured with transfected and nontransfected 3AO for 48 hours. cytotoxicity of PBLs on 3AO was detected by the MTT assay. RESULTS: The morphology of IL-2-transduced 3AO and IL-2R-transduced PBLs remained unchanged. 3AO cells could be transfected with the IL-2 gene and expressed IL-2 mRNA, and PBLs could be transfected with the IL-2R gene and expressed IL-2R mRNA. IL-2 transduced 3AO cells enhanced their response to the cytotoxicity of PBLs. Furthermore, growth inhibition of PBLs to 3AO cells increased significantly when the IL-2R was transfected into PBLs and when the IL-2 gene was transfected into 3AO cells and the two were combined. CONCLUSIONS: IL-2R gene transduced PBLs are able to enhance their cytotoxicity on IL-2 gene transduced ovarian cancer cells. This method may be a new way to investigate IL-2 gene therapy for ovarian cancer.

Cell Count↗
PubMed2001

Immunity induced by DNA vaccine of plasmid encoding the rhoptry protein 1 gene combined with the genetic adjuvant of pcIFN-gamma against Toxoplasma gondii in mice.

OBJECTIVE: To construct the eukáryotic expression recombinant plasmid, pcIFN-gamma, as a genetic adjuvant and observe the immune responses elicited by pcDNA3-rhoptry protein 1 (pc-ROP1) combined with pcIFN-gamma against Toxoplasma gondii (T. gondii) infection in mice. METHODS: A fragment of the IFN-gamma gene was directly inserted into the pcDNA3 plasmid and identified by two restriction endonucleases digestion. pcIFN and pcROP1 DNA was injected into the left leg muscle of mice at a dosage of 100 micrograms, and a booster vaccination was given at the same dosage after two weeks. Control groups were injected with pcDNA3 blank plasmid or normal saline. At 30, 50 and 70 days after booster injection, kinetic tests were carried out: MTT assay for the proliferation response of T lymphocyte cells and the activity of NK cells, sandwich ABC-ELISA for the determination of IFN-gamma, IL-2 and IL-10; a serum enzymetic aassay for nitric oxide (NO) in sera and ELISA for the titer of IgG antibody in sera. RESULTS: The recombinant plasmid, pcIFN-gamma was constructed. The proliferation response of spleen T lymph cells, NK cell killing activity, and serum levels of IFN-gamma, IL-2 and NO in mice injected with pcROP1 and pcIFN-gamma were higher than in those injected with pcROP1 alone. There was no difference in IgG antibody levels between the two groups. CONCLUSION: The genetic adjuvant, pcIFN-gamma, could enhance the cellular immune response induced by DNA vaccine of pcROP1 in mice against Toxoplasma gondii infection.

Animals↗
PubMed2001

Management of hemangiopericytomas in the central nervous system.

OBJECTIVE: To elucidate the clinical features and treatment of Hemangiopericytomas (HPCs) in the central nervous system. METHODS: Twenty-six HPC operations performed at Huashan Hospital from January 1993 to June 1999 were analyzed retrospectively, and a review of relevant literatures was done. RESULTS: Among the 26 cases, total tumor removal was achieved in 24 cases, and subtotal removal in 2 cases. Postoperatively, neurological symptoms were improved or unchanged in 21 cases, worsened in 4 cases, and pneumonia caused death in 1 case. Eighteen patients received postoperative radiotherapy. Eighteen patients were followed up from 1 month to 58 months (average, 22 months). During the follow-up period, 2 patients presented one or more distant metastasis, and one patient died of recurrence. CONCLUSION: Surgical management is the best choice for treatment of patients with HPCs. Postoperative radiotherapy can postpone the risk of tumor recurrence.

Adolescent↗
PubMed2001

Heart rate variability and its response to thyroxine replacement therapy in patients with hypothyroidism.

OBJECTIVE: To analyze heart rate variability (HRV) and its changes with thyroxine treatment in patients with hypothyroidism. METHODS: HRV was analyzed using 24-hour electrocardiographic recording in 38 patients with hypothyroidism and 21 normal controls. The changes in HRV were evaluated for the 18 hypothyroid patients after 3 months of thyroxine therapy. RESULTS: The time domain measurements of HRV in hypothyroid patients were much lower than those in the control group. As to HRV frequency domain, the high frequency power was significantly higher, but the ratio of low frequency power to frequency power for hypothyroid patients was lower than in the controls. These abnormal changes of HRV measurements in hypothyroid patients were improved after treatment with thyroxine and were associated with recovery of serum concentrations of FT3 and FT4. CONCLUSIONS: Patients with hypothyroidism often have autonomic neuropathies with a higher level of vagal tone. These abnormalities could be partly improved by thyoxine therapy.

Adult↗
PubMed2001

In vitro study on the morphology of human blood dendritic cells and LPAK cells inducing apoptosis of the hepatoma cell line.

OBJECTIVE: To observe in vitro effects and morphological changes of human peripheral blood dendritic cells (DCs) on the ability of lymphokine and phytohaemagglutininum (PHA) activated killer (LPAK) cells to induce apoptosis of the human hepatoma cell line (BEL-7402, B). METHODS: Experimental groups were divided into LD group (DCs + L + B), L group (L + B), D group (DCs + B) and B group. The methods of neutral red uptake, ordinary light microscopy, electron microscopy, TDT mediated X-dUTP nick end labeling (TUNEL) were used. RESULTS: The difference between the D group and the B group was not distinct (P > 0.05). The difference between the LD group and the L group was distinct, with DCs + LPAK > LPAK (P < 0.01) in cytotoxicity. Apoptotic cells were TUNEL positive in light microscopy, and apoptotic nuclei were stained yellow brown and dark brown, with size and shape varying from cell to cell. Ultrastructural change in apoptotic tumor cells comprised of compaction and condensation of nuclear chromatin, and condensation of cytoplasm and apoptotic bodies. At the same time, LPAK cells manifested the characteristics of autophagic apoptosis, and there were some autophagic bodies in it. CONCLUSIONS: The combination of human blood DCs and LPAK cells could induce apoptosis of BEL-7402 cells effectively, with some LPAK cells manifesting the characteristics of autophagic apoptosis.

Apoptosis↗
PubMed2001

The clinical and pathological characteristics of Chinese patients with pauci-immune crescent glomerulonephritis.

OBJECTIVE: To investigate the clinical and pathological characteristics of pauci-immune crescent glomerulonephritis (PICGN) in Chinese patients. METHODS: During 13 years (1985-1998), 6400 patients underwent non-transplanting renal biopsy. Twenty-four patients were diagnosed as PICGN. All clinical and laboratory data of these patients were collected from the patients' records and used for detailed analysis. The diagnosis is based on clinicopathologic findings. RESULTS: Of the 24 patients, 16 were females and 8 were males, with median age of 33 years (ranged 10-76 years). Microscopic polyarteritis (MPA) (33.3%) and systemic vasculitis (8.3%) were the secondary diseases. The incidence of PICGN was 0.38% in renal biopsies and 22.9% in crescentic glomerulonephritis. Clinically, most patients (75.0%) showed rapidly progressive nephritis with enlarged kidneys. At onset, gross hematuria was noted in 58.3% of patients, hypertension in 45.8%, nephrotic syndrome in 41.7%, and oliguria in 25.0%. However, systemic symptoms were rare except for anemia. Pathologically, necrosis of glomerular capillaries (62.5%), infiltration of monocytes and neutrophil cells in glomeruli (66.7%), and vasculitis in the interstitium (53.3%) were observed. In addition, glomerulosclerosis was noted in 45.8%, severe tubular atrophy in 83.3% and interstitial fibrosis in 75.0%. Anti-neutrophil cytoplasmic antibodies (ANCAs) were positive in 52.2%. All patients except two received intensively immunosuppressive therapy. Sixteen patients were available for long-term follow up (median 29.8 months, range 8-92 months). Twelve of them had life-sustaining renal function, four had normal serum creatinine (< 124 mumol/L) and only 4 patients were dialysis-dependent. CONCLUSION: PICGN is not rare in China. Early diagnosis and administration of immunosuppressive therapy, particularly in patients with rapidly progressive glomerulonephritis (RPGN), are important for good prognosis.

Adolescent↗
PubMed2001

[Value of P-glycoprotein and glutathione S-transferase-pi as chemo-resistant indicators in ovarian cancers].

OBJECTIVE: This study was conducted to assess the predictive value of P-glycoprotein (P-gp) and glutathione S-transferase-pi(GST-pi) as indicators of resistance to chemotherapy in ovarian cancers. METHODS: Expressions of P-gp and GST-pi were immunohistochemically studied in paraffin sections from 30 normal ovaries and 74 resected specimens of primary epithelial ovarian cancer from patients who had not received any chemotherapy before surgery. RESULTS: There were no detectable P-gp or GST-pi expression in the 30 patients with normal ovaries. In 74 cases of ovarian cancer tissue, P-gp was positive in 14 (18.9%) and GST-pi positive in 55 (74.3%) showing a highly significant correlation (P < 0.01). However, expression of P-gp and GST-pi was not associated with any of the clinicopathological parameters, such as clinical stage, histologic or tumor grade (P > 0.05). The evaluation of chemotherapy for postoperative residual ovarian cancer patients showed that all the six lesions showing P-gp positive were drug-resistant whereas only nine of the twenty-one tumors showing negative results were drug-resistant. Of 27 clinically measurable resected lesions, this difference in the response rates of the two groups was significant (P < 0.05). The predictive value of positive P-gp stain for drug resistance was 100% (6/6), and that of negative stain for objective responders was 57.1%(12/21). The response rate to chemotherapy of the GST-pi positive group (13.3%-2/15) was significantly lower than that of the SGT-pi negative group (83.3%-10/12, P < 0.01). The predictive value of positive GST-pi stain for drug resistance was 86.7%(13/15) and that of negative stain for objective responders was 83.3%(10/12). The survival rates of P-gp negative and GST-pi negative tumor patients were significantly higher than those of P-gp positive and GST-pi positive tumor patients (P < 0.01, P < 0.05, respectively). CONCLUSION: These data suggest that P-gp and GST-pi expression in tumor cells are related to drug resistance in epithelial ovarian cancer. They are useful indicators of resistance to chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

[Relationship between follicular development and insulin like growth factor I receptor in stimulated cycles].

OBJECTIVE: To investigate the number of follicles and insulin-like growth factor I receptor (IGF-I R) in stimulated cycles. METHOD: IGF-I R mRNA and IGF-I R in granulosa cells obtained during oocyte retrieval were respectively measured by reverse transcript polymerase chain reaction (RT-PCR) and Western blot technique. RESULTS: The expression of IGF-I R mRNA in poor responders (follicles < or = 3) was much lower than in normal responders (follicles 4-13) and high responders (follicles > or = 14) (1.70 +/- 0.23, 2.92 +/- 0.49, 4.22 +/- 1.50 respectively). Similar results were obtained for IGF-I R (1.32 +/- 0.31, 2.01 +/- 0.72, 4.39 +/- 2.31 respectively). CONCLUSION: The expression of IGF-I R correlated with the effects of gonadotropin hormone on follicular development.

Adult↗
PubMed2001

[To select and measure the biomechanical properties of bone of rat].

In the experimental studies designed to evaluate the effects of different factors on the biomechanical properties of bone, careful selection of rats and the scientific indices is very important. The aim of this paper is to recommend some essential methods for testing and calculating the biomechanical properties of rat bone such as tension, compression, bending and torsion.

Algorithms↗
PubMed2001

The distribution and significance of renal infiltrating cells in patients with diffuse crescentic glomerulonephritis.

OBJECTIVE: To study the significance and distribution of renal infiltrating cells, including monocytes (CD68+ cells), proliferative cell nuclear antigen positive cells (PCNA+ cells), CD4+ and CD8+ cells in diffuse crescent glomerulonephritis (DCGN). METHODS: Fifty-six patients with DCGN were studied, including 10 cases of anti-glomerular basement membrane (GBM)--type I DCGN, 26 immune complex--type II DCGN, and 20 cases of pauci-immune--type III DCGN. Glomerular and interstitial infiltrates of CD68+ and PCNA+ cells, and interstitial infiltrates of CD4+ and CD8+ cells were detected by using four-layer PAP methods. RESULTS: There was a significant increase of renal infiltrating CD68+, PCNA+, CD4+ and CD8+ cells in patients with DCGN compared with that in normal controls. In patients with type I DCGN, there was a higher number of renal infiltrating CD68+ and PCNA+ cells than that in patients with type II and III DCGN. A glomerular infiltrates of CD68+ and PCNA+ cells correlated with the interstitial infiltrates of CD4+ cells in type I or III DCGN patients. In lupus DCGN patients, the numbers of renal infiltrating CD68+ and PCNA+ cells were similar to vasculitis or type III DCGN patients. CONCLUSION: These findings demonstrate that the renal infiltrates of CD68+ and PCNA+ cells play an important role in patients with DCGN, that the infiltrates of CD4+ cells correlate with the infiltrates of CD68+ and PCNA+ cells may be an active marker of DCGN, and that cell-mediated immunity may contribute to crescent formation in lupus DCGN patients.

Adolescent↗
PubMed2001

Cyclosporin A treatment for idiopathic membranous nephropathy.

OBJECTIVE: To evaluate the efficacy of cyclosporin A (CSA) in the treatment of idiopathic membranous nephropathy (IMN), a prospective controlled clinical study was performed. METHODS: This study included a group of 30 IMN patients, among them 15 were treated with CSA and 15 with captopril (CAP). The diagnosis of IMN was made with exclusion of secondary forms of membranous nephropathy by extensive clinical and pathological studies. No patients received steroids or cytotoxic agents for six months prior to enrollment. In the CSA group, CSA was given at an initial dosage of 5 mg.kg-1.d-1, gradually tailed off over the first three months and maintained at 2 mg.kg-1.d-1 for 12 months. In the CAP group, CAP was given at a dosage of 37.5 mg/day. RESULTS: In the first three months, 6 (6/15) complete remissions (CR) and 2 (2/15) partial remissions (PR) were observed in the CSA group while only 2 (2/15) PRs were observed in the CAP group. Before the end of the 15-months, 8 patients in the CSA group experienced CR and 4 patients experienced PR. One CR patient relapsed as the dosage of CSA was reduced, so 7 patients remained in CR at the end of the first 15-months. No additional CR or PR was observed in the CAP group during late follow-up. At the last visit (an average follow-up time of 44 months) in the CSA-group, another 2 CR patients had relapsed and 1 CR patient shifted to PR after stopping the CSA treatment, so 4 CR and 5 PR remained in the CSA group. In the CAP group, 3 spontaneous CRs occurred beyond 1.5 year's follow-up, with 3 CR and 2 PR at the last visit. No difference was found between the averages of the initial and the last serum creatinine levels in either group. No serious adverse effects were found during CSA treatment. Re-biopsy data of three patients responsive to CSA treatment showed that no pathological improvement of glomerular basement membrane was observed, even in cases at remission. Tubulointerstitial fibrosis was found in 1 relapsed CR patient, whose serum creatinine increased above the normal range, but not in the other 2 patients whose serum creatinine remained in the normal range. CONCLUSIONS: CSA therapy at a dosage of 5 mg.kg-1.d-1 is effective in inducing remission of nephrotic syndrome in adult IMN patients within three months, with a response rate of 80%. A relatively high rate of relapse (50%) was observed within 2 years after the withdrawal of CSA treatment.

Adult↗