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Biomedical subjects

Z Chen

Publications and source records attributed to Z Chen.

At least 667 records · Page 37Linked to original sources
PubMed1999

[Evaluation on the establishment and operation on neonatal tetanus surveillance program in Hainan Province].

OBJECTIVE: In order to learn the actual morbidity and influencing factors of neonatal tetanus(NNT) and to provide scientific basis for NNT elimination. METHODS: A surveillance program was set up in 1997 in Hainan Province and to operate at the same time. RESULTS: 216 NNT cases were investigated in 1997. The number was higher than reported 78 cases. The result from surveillance showed that parturition at home and the old delivering method were the main influencing factors 88.89% of mothers of NNT cases had no TT immunization history. The surveillance data of Sanya City and Qiongzhong County indicated the NNT morbidity in 1997 had declined 61.29%, 82.05% than that in 1996 respectively due to the improvement of TT immunization rate. CONCLUSION: The study result proved that the most economical and effective measure to eliminate NNT is to increase TT immunization rate of women at child-bearing-age. It was practical integrate the NNT surveillance program into AFP surveillance system and operate along with it.

China↗
PubMed1999

A fast, sensitive and specific method for rice dwarf virus detection by northern blot hybridization.

Based on stability of double-stranded (ds) RNA, a new, fast, sensitive, and specific method for detection of genomic rice dwarf virus (RDV) dsRNA by molecular hybridization was developed. In contrary to the commonly used, standard Northern blot analysis, dsRNA is denatured in the immobilized state on the blot. Therefore, risk of degradation of single-stranded (ss) RNA by ribonuclease (RNase) during sample preparation, electrophoresis and blotting is eliminated. This method overcomes disadvantage of incomplete denaturation of dsRNA in Northern blot analysis. In conclusion, the newly developed method is reliable, sensitive, very specific, and gives a low background. The entire procedure is also less time consuming; it can be completed within 2-3 days. The new method may be regarded as a modification of the standard Northern blot analysis.

Blotting, Northern↗
PubMed1999

[Research on immunological activity of non-immunological cells of decidua in normal early pregnancy].

OBJECTIVES: To investigate the immunological activity of non-immunological cells of decidua in normal early pregnancy. METHODS: Harvest the supernatant from cultured non-immunological cells of decidua. Inspect the effects of the supernatant on transforming function of T cells, killing activity of natural killer cells, the IgG secretion of B cells and the interleukin-2 (IL-2) secretion by lymphocytes of human peripheral blood by radioimmunological assay (RIA). RESULTS: The supernatant of the cultured non-immunological cells of decidua can inhibit the immunological function of T cells, natural killer cells and B cells to different extents, their maximum inhibiting ratio were 22.7%, 52.3% and 14.8% respectively, but there is no significant effect on the IL-2 secretion by lymphocytes. CONCLUSIONS: The non-immunological cells of decidua in normal early pregnancy have immunological inhibiting function, which might contribute to prevent fetus from being expelled by maternal immunological system.

Cells, Cultured↗
PubMed1999

[Analysis of fibronectin and laminin in the extracellular matrixes of acute myeloid leukemia and its implications].

OBJECTIVE: To investigate the relationship between quantitative change of fibronectin (Fn) or Laminin (Lm) and growth and differentiation of leukemic cells. METHODS: The extracellular matrixes, Fn and Lm, in long-term bone marrow culture (LTBMC) from 18 acute myeloid leukemia (AML) patients and 6 normal subjects were examined by immunofluorescence assay. RESULTS: 1. The Fn or Lm content in 9 AML self-maintained (AMLsm) 1-3 week-cultures was significantly less than that in 9 AML not self-maintained (AMLnsm) cultures. 2. In the third week's cultures, the blasts of 8 AMLnsms decreased to less than 5%, but did not of 7 AMLsms. 3. As the cultures going on, the blasts were related to Fn or Lm contents positively in normal control and negatively in AMLnsm. The blasts were related to Fn contents negatively in AMLsm. CONCLUSION: The change of Fn or Lm may play an important role in the development of AML. In addition, the difference of Fn or Lm contents between AMLsm and AMLnsm was helpful to the choice of AML patient for in vitro purging of leukemic cells through LTBMC before auto-BMT.

Adolescent↗
PubMed1999

Combination of all-trans retinoic acid with butyric acid and its prodrugs markedly enhancing differentiation of human acute promyelocytic leukemia NB4 cells.

OBJECTIVE: To use NB4, an authentic human acute promyelocytic leukemia cell line, as well as the marrow cells from patients with acute promyelocytic leukemia (APL), containing the PML/RAR alpha fusion gene and fused protein to examine the growth inhibition and cytodifferentiation induced by all-trans retinoic acid (ATRA), butyric acid (BA) and its prodrug tributyrin (TB) either as a single agent or in combinations. METHODS: NB4 and APL cells were cultured in presence of ATRA, BA and TB respectively either as a single agent or in combinations at various concentration ratio. Cell growth was measured and myeloid differentiation was determined by morphology and the percentage of positive nitroblue tetrazolium reduction (NBT) on consecutive days over the whole process of culture. RESULTS: NB4 cells can be induced by ATRA alone and synergistically induced by the combinations of BA or TB with ATRA to differentiate. The synergy was reflected by a remarkable decrease in the effective concentration of ATRA required in the combinations in comparison with it as a sole agent. The combinations also shortened the time for the cells to reach the same level of maturation as that needed for ATRA alone. The potentiation on ATRA-induced differentiation of NB4 cells seemed depending on an appropriate concentration ratio of each inducer in the combinations and the time of action. A preliminary result of in vitro induction of primarily cultured leukemic cells from APL patients by the combined inducers was promising. CONCLUSION: The combinations of ATRA with BA or TB at an appropriate ratio may improve the clinical outcome of differentiation therapy for APL patients.

Butyric Acid↗
PubMed1999

[The study and application of the alar cartilage ring in the treatment of deformities of unilateral cleft lip nose].

OBJECTIVE: To explore the possible pathogenesis and to look for effective reconstructive procedures of unilateral cleft lip nose. METHODS: The author has had a detailed comparative study by comparing the cartilaginous skeleton of 20 normal cadaver specimens with that of one unilateral cleft lip stillborn, as well as intraoperative findings of 24 clinical patients. RESULTS: There are two alar cartilaginous rings, namely alar cartilaginous fibrous ring and alar cartilaginous muscular ring, in external nose. Both rings are hypoplastic in the cleft lip patients. According to the findings, the author designed and applied a new operation procedure to reconstruct alar cartilage ring for 24 patients from 1994 to 1997. An acceptable short-term results were found. CONCLUSION: Alar cartilaginous fibrous ring and alar cartilaginous muscular ring are very important anatomic structures to maintain the shape of the lower part of the nose. Hypoplasia of these rings is an important factor leading to deformities of the nose. It is very important to reconstruct alar cartilage ring for the patients with unilateral cleft lip nose.

Abnormalities, Multiple↗
PubMed1999

[Protective effect of exogenous pulmonary surfactant on pulmonary function during cardiopulmonary bypass in children].

OBJECTIVE: To study the protective effect of exogenous pulmonary surfactant (PS) on respiratory insufficiency after cardiopulmonary bypass in children. METHODS: 24 children of VSD associated with pulmonary hypertension undergoing heart surgery with cardiopulmonary bypass(CPB) were randomly divided into two groups: control group and PS group. In the PS group, exogenous natural porcine PS 150 mg/kg was dropped into the intracheal tube before opening the chest and removing the aortic clamp. Equal amount of normal saline was given in the control group. Lung dynamic compliance and oxygenate index were measured before and after operation. The plasma molondialdehyde(MDA) concentration of the lung was analysed perioperatively with ELISA methods. The intubation time of the two groups and ultrastructure of the lung also was measured. RESULTS: The dynamic compliance of the PS group was higher than that of the control group (P < 0.05), and the oxygenate index was significantly lower than that of the control group (P < 0.01) after CPB. Compared to the control group, the exogenous PS was able to markedly reduce the generation of MDA(P < 0.01). The intubation time of the PS group was 8.9 hours, much shorter than 13.8 hours of the control group(P < 0.001). The histological examination confirmed that the degree of pulmonary damage was significantly ameliorated in the PS group. CONCLUSION: Exogenous natural PS has protective effect on respiratory insufficiency after CPB in children with VSD associated with pulmonary hypertension.

Cardiopulmonary Bypass↗
PubMed1999

[The association between signal-regulatory protein alpha and hepatocellular carcinoma].

OBJECTIVE: To study the roles of signal-regulatory protein alpha (SIRP alpha) in the development of hepatocellular carcinoma (HCC). METHODS: 42 pairs of HCC and the surrounding noncancerous hepatic tissues were used. The expression of SIRP alpha in various tissues was determined by Northern blot analysis and immunohistochemistry assay, by which together with the pathologic characteristics of each sample, the role of SIRP alpha was investigated. RESULTS: The expression of SIRP alpha significantly decreased in 21 cases of samples (50.0%) to the 3.9 kb transcript and 27 cases of samples (64.3%) to the 2.5 kb transcript respectively. The SIRP alpha decreasing rate in large HCC(> 5 cm in diameter) was higher than in small HCC (< or = 5 cm in diameter), and in HCC with cancer embolus was higher than that of without cancer embolus. No association was found between the SIRP alpha expression and the patient's age, tumor grade, tumor capsule, serum AFP level, and HBV infection. Immunohistochemistry showed that all the normal hepatocytes, cholangioepithelial cells, Ito cells, regenerated hepatocytes, new generated cholangioepithelial cells and part of HCC cells were positive. The HCC tissues in which SIRP alpha was down-regulated showed positive particles becoming weaker and less, and some tumor cells and area were completely negative. CONCLUSION: The expression of SIRP alpha especially 2.5 kb transcript is down-regulated in HCC, which is closely related with the tumor growth and invasiveness. SIRP alpha may be an important negative regulator of HCC.

Antigens, Differentiation↗
PubMed1999

MRI evaluation of bone marrow of normal lumbar vertebra in the Chinese: normal patterns and preliminary quantitative study.

OBJECTIVES: To establish the normal patterns of lumbar vertebral marrow in normal Chinese, to determine its normal value of relaxation times (T1 and T2), and to investigate the relationship between relaxation time and age or sex. METHODS: 320 of 1000 cases (sampled randomly) received MR imaging. According to the MRI findings of sagittal T1WI, marrow patterns were established. 268 cases were studied quantitatively (T1 and T2 measurements). RESULTS: The normal bone marrow patterns of lumbar vertebra were divided into four main patterns (six subgroups). The normal values of relaxation times (T1 and T2) were measured. T1 or T2 value decreased with aging. No significant difference in T1 value between two sexes (< 40 years old: u = 0.4307, P > 0.50; > or = 40 years old: u = 0.554, P > 0.05). No significant difference was seen in T2 value between two sexes before 40 years old (u = 1.3628, P > 0.10), but significant difference after 40 years old (u = 2.1498, P < 0.05). CONCLUSIONS: To establish the normal patterns of lumbar vertebral marrow and determine its normal values of relaxation times have important clinical value in the diagnosis of bone marrow diseases.

Adolescent↗
PubMed1999

Effects of nitric oxide inhibitor on prostacyclin biosynthesis in portal hypertensive rats.

OBJECTIVE: To evaluate the effects of nitric oxide inhibitor on prostacyclin (PGI2) biosynthesis and the role of PGI2 in hyperhemodynamics of portal hypertension. METHODS: Sprague Dawley rats were divided into four groups: intrahepatic portal hypertension (IHPH) by injection of CCl4, prehepatic portal hypertension (PHPH) by stenosis of the portal vein, end-to-side portacaval shunt (PCS), and sham-operated controls (SO). Animals of each group were subdivided into 2 groups: systemic administration of nitric oxide inhibitor L-NMMA and vehicle. The radioactive microsphere method was used for hemodynamic study. The level of plasma PGI2 (6-keto-PGF1 alpha) was measured by radioimmunoassay. RESULTS: The characteristics of hyperdynamic circulatory state including increased cardiac output and splanchnic blood flow, decreased mean arterial blood pressure, total peripheral vascular resistance, and splanchnic vascular resistance were observed in IHPH, PHPH and PCS rats. The magnitude of hyperhemodynamics was in the order of PCS > PHPH > IHPH rats. The hyperdynamic circulatory state in IHPH, PHPH and PCS rats could be effectively reversed by L-NMMA to the baseline values of hemodynamics in SO rats. The baseline concentrations of plasma 6-keto-PGF1 alpha (ng/ml) in PHPH, IHPH, PCS, and SO rats were 6.93 +/- 2.43, 5.09 +/- 2.27, 2.36 +/- 1.01 and 1.56 +/- 0.61, respectively. The concentrations of plasma 6-Keto-PGF1 alpha in PHPH, IHPH and PCS rats were significantly higher than those in SO rats. Moreover, the concentrations were significantly higher in PHPH and IHPH rats than in PCS rats (P < 0.05). After administration of L-NMMA, the concentrations of plasma 6-Keto-PGF1 alpha (ng/ml) in PHPH, IHPH, PCS and SO rats were 7.69 +/- 2.98, 5.68 +/- 2.66, 5.50 +/- 0.79, 5.02 +/- 2.86, respectively. As compared to the baseline value, the concentrations of 6-keto-PGF1 alpha rats were slightly increased in IHPH, PHPH rats (P > 0.05), but significantly increased in PCS and SO rats (P < 0.05). CONCLUSIONS: In this study, the hyperdynamic circulatory state in portal hypertensive rats and portacaval shunt rats was completely reversed by L-NNMA to normal, but the level of 6-keto-PGF1 alpha was still elevated. The results indicate that PGI2 is not involved in hyperhemodynamics of portal hypertension.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

[Qiu Xi and vaccination].

Qui-Xi was one of the earliest Chinese who learned cowpox vaccination in the early 19th century. He spent all his life on vaccination career, explained and supplemented the cowpox vaccination by TCM theory, and thus did great contribution to the prevention of smallpox in China. Guangdong, as an early trade window opening to abroad, provided an environment of social thought and economic support to him.

China↗
PubMed1999

[Genetic polymorphisms of homocysteine metabolism related enzymes in patients with coronary heart disease].

OBJECTIVE: To study genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T and cystathionine beta-synthase(CBS) T833C related to homocysteine metabolism in patients with coronary heart disease (CHD). METHODS: 209 patients with CHD and 101 controls were selected. MTHFR genetic C677T polymorphism was determined by PCR-RFLP, and CBS T833C polymorphism by ARMS method. Plasma homocysteine levels were detected with HPLC. RESULTS: The frequencies of MTHFR T homogenetic type and heterogenetic type (27.8% and 45.4%) in case group were higher than those in normal group(22.8% and 34.6%). There were significant differences in the frequencies of genotypes and alleles between two groups (P < 0.05). C homogenotype of CBS gene was found in 21 patients, and 2 in the normal group. There were evident differences in the frequencies of genotypes and alleles of the two groups (P < 0.001). Moreover, plama homocysteine levels were markedly higher in patients with MTHFR or CBS genetic mutation than those in patients without mutation (P < 0.05). CONCLUSIONS: Hyperhomocysteinemia is an independent risk factor of CHD. MTHFR and CBS are the main enzymes related to homocysteine metabolism. Their genetic mutations are possibly important mechanism of hyperhomocysteinemia and coronary heart disease.

Adult↗
PubMed1999

Effect of rhein on glucose transporter-1 expression and its function in glomerular mesangial cells.

OBJECTIVE: To explore the effect of rhein on the regulation of glucose transporter-1 (GLUT1) overexpression and the possible molecular mechanism that rhein antagonize the effect of transforming growth factor beta 1 (TGF-beta 1) in glomerular mesangial cells. METHODS: Cultured mouse mesangial cells were used. The expression of GLUT1 mRNA was detected by Northern blotting; the ability of glucose uptake was determined by 2-deoxy-[3H]-D-glucose uptake assay. RESULTS: Rhein had no effect on glucose uptake in mesangial cells cultured in normal glucose concentration. TGF-beta 1 could upregulate the expression of GLUT1 mRNA and glucose uptake in mesangial cells. This effect was markedly attenuated by the addition of rhein in a dose dependent manner. CONCLUSIONS: TGF-beta 1 could upregulate the expression of GLUT1 mRNA and glucose uptake in mesangial cells, resulting in excessive glucose consumption and extracellular matrix production in diabetic nephropathy. Rhein antagonized the effect of TGF-beta 1 in mesangial cells, so it might be a hopeful remedy for the treatment of patients with diabetic nephropathy.

Animals↗
PubMed1999

Effect of immunization in mice with recombinant DNA encoding the hepatitis C virus structural protein.

OBJECTIVE: To explore the possibility and the efficacy of immune responses in mice inoculated with recombinant plasmid pCD-HCV1 and to lay a foundation for HCV nucleic acid vaccine development in the future. METHODS: The gene fragment coding C and E regions of HCV-II (type I b) was inserted into pCD-SR alpha 1 expression vector and formed pCD-HCV1 and then was injected into quadriceps muscles of Balb/c mouse. Serum anti-HCV level of mice was tested by ELISA (A value). Spleen cells proliferation responses to HCV antigens were detected by 3H-TdR incorporation (cpm). RESULTS: Balb/c mice immunized with recombinant plasmid pCD-HCV1 three or four times can generate specific antibody responses to HCV antigens and the antibody levels gradually ascend to the plateaus and did not have the trend of descending in 18 weeks detected. The serum antibodies in mice immunized by recombinant plasmid pCD-HCV1 were 100 percent positive when the serum were diluted 40 times and the positive rate of antibody still were 16.6 percent positive when the serum were diluted 320 times. Balb/c mice immunized with recombinant plasmid pCD-HCV1 (100 micrograms, 50 micrograms 10 micrograms/mouse three times respectively) can elicit antibody responses to HCV antigens and the antibody levels of three groups were 0.70 +/- 0.07, 0.33 +/- 0.04 and 0.11 +/- 0.09 respectively. Spleen cells of Blab/c mice injected with pCD-HCV1 three times were induced to produce proliferation responses to HCVc + e specific antigens. CONCLUSIONS: These results demonstrated that constructs expressioning HCV core and envelope proteins can generate anti-HCVc + e specific antibody responses and lymphoproliferation responses in mice, which suggested it to be possible to elicit immune responses to viral epitopes from HCV via DNA immunization with HCV-DNA recombinant and to warrant further investigation as a potential vaccine against HCV infections.

Animals↗
PubMed1999

Differentiation therapy for acute promyelocytic leukemia with all-trans retinoic acid: 10-year experience of its clinical application.

PURPOSE: To summarize the experiences in using all-trans retinoic acid (ATRA) for the differentiation therapy for acute promyelocytic leukemia (APL) since our introduction of its use in clinic in 1986. DATA RESOURCES: Data resources came from Chinese Journal of Hematology, English-language literature using MEDLINE (1988-1998), book entitled "Treatment of Malignancies by Inducing Differentiation and Apoptosis" published by Shanghai Publishing House on Sciences and Technology, and our recent data to be published. STUDY SELECTION: Thirty-five articles related to the purpose of this review were reviewed. DATA EXTRACTION: Data were checked for their quality, reliance and originality. RESULTS: ATRA combined with chemotherapy can decrease the incidence of retinoic acid syndrome and produce a very high remission rate (90%-95%). Post-remission treatment should include chemotherapy and ATRA, the 5-year survival probability was able to attain 0.71 +/- 0.06. The main problem in the treatment is early tolerance to ATRA and relapse of the disease. The most effective treatments for relapsed APL is to use arsenic trioxide. CONCLUSION: The combination of ATRA, chemotherapy and arsenic oxide in the treatment of APL for elevating the remission rate and prolonging survival time deserves further study.

Antineoplastic Agents↗
PubMed1999

[The effect of cyclooxygenase-2 inhibitor on acute lung injury].

OBJECTIVE: To investigate changes of cyclooxygenase-2 (COX-2) mRNA expression and intervention effect of selective cyclooxygenase-2 inhibitor Meloxicam on acute lung injury (ALI). METHODS: We measured COX-2 mRNA expression by reverse-transcription polymerase chain reaction in rat lung with ALI induced by lipopolysaccharide, and observed changes of prostaglandins (PGs), PaO2 and histopathology. RESULTS: Resting rat lung expressed a little COX-2 mRNA; expression of cyclooxygenase-2 mRNA was up-regulated significantly in the lung after rats were injured by LPS. Selective COX-2 inhibitor Meloxicam alleviated histopathologic damage in the lung, inhibited production of PGs and attenuated PaO2 decline. CONCLUSIONS: COX-2 is a main isoform responsible for enhancing PGs production during ALI. Meloxicam can inhibit activity of COX-2 and may be useful in the treatment of ALI.

6-Ketoprostaglandin F1 alpha↗