Biomedical subjects

Y Wei

Publications and source records attributed to Y Wei.

At least 217 records · Page 12Linked to original sources

PubMed1998

Hydralazine, but not captopril, decreases free radical production and apoptosis in neurons and thymocytes.

The effects of captopril and hydralazine, two commonly used antihypertensive drugs, on free radical generation and the onset of apoptosis in neuron and thymocyte preparations from 10-12 day old rats have been studied. Apoptosis was induced in neurons by kainate or N-methyl-D-aspartate and in thymocytes by heat shock. Intracellular free radical production was measured by 2',7'-dichlorofluorescein fluorescence, and apoptotic cells were detected by cell staining with fluorescein-labelled annexin V. Captopril was found to have no effect on intracellular free radical generation and also had no significant effect on the early stages of apoptosis in neurons and thymocytes. In contrast, hydralazine was found to decrease free radical generation in both neurons and thymocytes, and it also significantly decreased the numbers of apoptotic cells when neurons and thymocytes were stimulated for apoptosis. Hydralazine had a greater effect on decreasing free radical generation in neurons than in thymocytes, but it had a more pronounced effect on decreasing apoptosis in thymocytes compared to neurons, suggesting that apoptosis, under our experimental conditions, may not solely be triggered by free radical generation. These results contrast with earlier reports that captopril is a free radical scavenger and can decrease apoptosis in T-lymphocytes and cardiomyocytes, and the results obtained with hydralazine are in apparent disagreement with earlier reports that this drug is a free radical generator and can cause intracellular damage suggestive of enhanced free radical formation.

Animals↗

PubMed1998

Protective effect of anisodamine on reperfusion injury of skeletal muscles in rabbit.

Anisodamine is an alkaloid isolated from a Chinese plant, which was subsequently synthesized. Its chemical structure is similar to atropine. It inhibits cholinergic nerve function, improves microcirculation, and was reported to have a protective effect on reperfusion injury in various organs. We used anisodamine in a rabbit model with ischemia and reperfusion injury of hind limb muscles. We evaluated its effect on skeletal muscle cells, using transmission electron microscopy, and analyzed lipid peroxidation by measuring malondialdehyde and lactate dehydrogenase blood concentrations. We found that malondialdehyde and lactate dehydrogenase concentrations after 1 hour of reperfusion were lower in animals treated with anisodamine than in controls. Damage to membrane structures and myofilaments in muscle cells was less severe after anisodamine treatment. Our findings indicate that anisodamine protects skeletal muscles with ischemia and reperfusion injury.

Animals↗

PubMed1998

[Detecting expression of the multidrug resistance gene product (P170) in human tumor tissues and cells by flow cytometry].

We have detected the human multidrug resistance gene (MDR1) product P170 in 29 solid tumor samples and K562 cell line through indirectimmunoflourence staining by flow cytometry using mouse monoclonal antibody (McAb). The results showed that the expression of P170 was detected in 18 samples, the positive ratio being 62.1%; the expression was not detected in 11 samples, the negative ratio being 37.9%; and 99.9% of K562 cells expressed P170. In 16 of the 18 positive samples, the percent ratio of tumor cells for expression of P170 was less than 30%; in the other 2, more than 30%. This indicated that the positive ratio of P170 of most tumor samples was high, but their percent ratio of P170 was low. Thus it provided a parameter for reference in evaluating the efficacy of clinical antitumor treatments.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

[Effect of Ox-LDL on cell cycling phases and PCNA, P53, P27 and c-erbB-2 expression in cultured human arterial smooth muscle cells].

It was found in our previous study that oxidative modification LDL (Ox-LDL) could stimulate the proliferation of cultured human arterial smooth muscle cells (SMC). Yet, the mechanism responsible for the SMC proliferation induced by Ox-LDL is not clear. Proliferating cell nuclear antiger (PCNA), P53 and P27 are the key regulatory factors of cell replication. In order to observe the effects of Ox-LDL on cell cycling phase and PCNA, P53, P27 and c-erb B-2 expression in SMC, we used the flow cytometric method in the present study on the proliferation of cultured human SMC induced by Ox-LDL. The results showed a relation between the Ox-LDL mediated SMC proliferation and the cycling phase shifting. The relative number of S phase cells in the Ox-LDL group was higher than that of the control group (22.9% vs 15.7%). Ox-LDL mediated SMC proliferation was accompanied with the increasing expression of PCNA. The percentage of specific PCNA positive FITC cells in the Ox-LDL group was significantly higher than that of the control group (12.6% vs 6.5%). PMA, an activitor of protein kinase C (PKC), stimulated SMC proliferation and increased the PCNA exression in cultured SMC, while the PKC inhibitor, F109203X, significantly decreased the PCNA expression in SMC (PCNA positive cells 13.4% vs 0.4%). No changes were observed in the expression of P53, P27 and c-erb B-2 in the cultured proliferating SMC induced by Ox-LDL. In all, the results suggest that the OX-LDL mediated SMC proliferation is related to increasing S Phase Cells and involved in the PCNA expression which might undergo the PKC cellular signal transduction pathway.

Aorta↗

PubMed1998

[Effect of vasectomy on apoptosis in spermatogenic cells of the male rat].

To explore the effect of vasectomy on apoptosis of spermatogenic cells, we have detected apoptosis in the testis of vasectomized and sham-operated adult rats within a period of 12 postoperative weeks by means of flow cytometry and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuride triphosphate nick-end labeling) method. Flow cytometry found that, in vasectomized rat, the sub-haploid peak was higher and the percentage of cells with sub-haploid was increased. The total number of positive TUNEL cells in the vasectomized group was greater than that in the sham-operated group (P < 0.001). Compared with the same time-phased sham-operated subgroups, the number of apoptotic spermatogonia and primary spermatocytes in the testes of the subgroups 2 weeks, 6 weeks and 10 weeks after vasectomy as well as the number of spermatogonia of the subgroup 12 weeks after vasectomy were significantly higher (P < 0.05). These findings demonstrate that vasectomy could enhance the apoptosis of spermatogenic cells.

Animals↗

PubMed1998

Immunohistochemistry and reverse transcription-polymerase chain reaction for detecting adrenomedullin in the central nervous system.

OBJECTIVE: To demonstrate the presence of adrenomedullin in the central nervous system. METHODS: Using immunohistochemical method (ABC) and reverse transcription-polymerase chain reaction (RT-PCR) analysis, the distribution of immunoreactive (IR-) AdM and AdM mRNA was observed in the rat and the human brain. RESULTS: Immunoreactive (IR-) AdM and AdM mRNA were detectable in almost every region of the rat brain examined, including cerebral cortex, paraventricular tissues, hypothalamus, mesencephalon, medulla oblongata and cerebellum. The levels of AdM mRNA in paraventricular tissues and medulla oblongata were higher than those in the other brain regions. AdM mRNA was also detectable in the human brain. CONCLUSION: The present study shows that AdM is present in the central nervous system, suggesting that AdM might act as a neurotransmitter, neuromodulator or neurohormone in rats or humans.

Adrenomedullin↗

PubMed1998

[Preparation of novel macroporous silica-based amide-polymer-bonded packing and its application to the separation of proteins].

A novel macroporous silica-based amide-polymer-bonded packing for protein separations in HPLC is described. The macroporous silica support was bonded with diethoxymethyl vinyl silane and then copolymerized with methylacrylamide and divinylbenzene to produce a tailored stationary phase with high resolution and inertness. The repeatability of packing preparation is good. They were characterized through the application of a standard protein mixture of pepsin, glucose oxidase, bean trypsinogen inhibitor and ribonuclease. The time for elution of these proteins is less than 12 minutes. It is suggested that the macroporous silica-based amide-polymer-bonded packing can be used to quickly separate biopolymer. This packing is a better alternative for the biopolymer separation.

Chromatography, High Pressure Liquid↗

PubMed1998

[Effect of Yangxue bushen tablet on ovarian function in animal model of Yang deficiency].

OBJECTIVE: To study the therapeutic mechanism of Yangxue Bushen tablet (tablet for nourishing blood and tonifying Kidney) on the Kidney deficiency type of functional amenorrhea and infrequent menstruation. METHODS: Applied with orimeten, models of Yang deficiency in female rabbits were made, ikaclomine was taken as the control drug. Group I was the group of animal model of Yang deficiency; Group II was the ikaclomine treatment group; Group III was the high dosage treatment group; Group IV was the low dosage group; Group V normal rabbit treated with distilled water. The functional effect of gonadal axis was evaluated by the changes of the signs of animal histomorphology of ovary and uterus, and the level of beta-endorphin. RESULTS: The animals of Yang deficiency in Group II, III and IV recovered as a whole, and the changes of different levels of folliculi, morphosis of endometria and deciduous vaginal epithelial cell in group II, III and IV were more obviously than those in group I and V (P < 0.05). The content of beta-endorphin in blood plasma in group I was 106.6 pg/ml, which was lower than those in the other groups (P < 0.05), and the contents of beta-endorphin in blood plasma, in group III, IV and II were similar to that in group V (P < 0.05). CONCLUSION: Yangxue Bushen tablet has the effect on regulating menstruation by regulating the function of gonadal axis, regulating and promoting the ovarian function.

Amenorrhea↗

PubMed1998

[Regularities of carbon monoxide outgassing from two nonmetallic materials at different temperatures].

To investigate the regularity of carbon monoxide outgassing from nonmetallic materials in air tight cabin, two nonmetallic materials was observed. 30-9304 foam plastics and aluminum-plated polyester adhesive film were sealed in airtight glass ampules, and outgassed for 70 days at four different temperatures. The outgassing CO was determined continuously with transform/gas chromatography. Curve fitting and regression were used in data analysis. The results showed that: (1) when temperature was kept constant, the relation between the outgassed CO and outgassing time appeared to be a "s" shaped or exponented curve; (2) at a fixed time the amount of outgassed CO increased with temperature exponentially; (3) the amount of CO outgassed in 12 h at 100 degrees C from the two materials corresponds those for 45 d at 50 degrees C, there is an iso-effect principle for CO outgassing.

Air Pollutants↗

PubMed1998

Effects of acute moderate hypoxia on human performance of arithmetic.

To observe the effects of acute moderate hypoxia on human performance of arithmetic, the continuous calculation test, addition-subtraction test and mental arithmetic tests were made in 16 health young male subjects during exposure to altitude of 300 m (control), 3600 m, 4400 m and 5000 m by mean of hypobaric cabin simulation. Error rate of the continuous calculation test and reaction time of addition-subtraction test increased significantly and performance decreased significantly (P < 0.05) after exposure to 3600 m for 1 h. Reaction time, total number and performance of all tests decreased significantly (P < 0.05) during exposure to 4400 m. Performance of all tests decreased (P < 0.01) after exposure to 5000 m for 30 min.

Adolescent↗

PubMed1998

[Experimental studies on anti-inflammatory, antipyretic and diuretic effects of several species of tongcao and xiao-tongcao].

OBJECTIVE: To observe and compare the anti-inflammatory, antipyretic and diuretic effects of three kinds of Tongcao(Tongtuomu, Panyezhangyeshu and Luosan) and seven kinds of Xiao-tongcao(Ximashanjinjiehua, Xinanxiuqiu1. 2., Ditanghua, Suixuezhangcai, Qingjiaye and Zhongguo jinjiehua). METHOD: Decoctions prepared from the above kinds of Tongcao and Xiao-tongcao crude drugs were given to rats at dosages of 8 g/kg and 4 g/kg by ig. Pharmacological actions were observed by means of carrageenan-induced swelling paws, fever models induced by beer-yeast or carrageenan and metabolic cage method in rats. RESULT: All the experimental decoctions could inhibit carrageenan-induced swelling of rat paws in different degrees and exerted anti-pyretic effect on rat fever models induced by beer-yeast or carrageenan. Three kinds of Xiaotongcao(Ximashanjingjiehua, Xinanxiuqui2., Zhongguojinjiehua) had obvious diuretic effect on rats. CONCLUSION: Decoctions of different species of Tongcao and Xiao-tongcao all have anti-inflammatory, antipyretic and diuretic effects, thus providing some pharmacologic basis for the efficacy assay, clinical application, species collation and quality study of Tongcao and Xiao-tongcao.

Analgesics, Non-Narcotic↗

PubMed1998

[Effect of yuanhua on isolated uterine strips in unpregnant rats].

OBJECTIVE: To explore the mechanism on the effect of Yuanhua on the contractile activity of isolated uterine strips in rats under artificial oestrum. METHOD: Isolated strips were suspended in a tissue chamber in which Yuanhua was added with some antagonists of inhibitors or without. RESULT: Yuanhua could excite the uterine smooth muscle strips in a dose-dependent manner, but atropine, phentolamine, hexamethonium and diphenhydramine could not inhibit this exciting action. This exciting effect could be inhibited completely by verapamil and decreased by indomethacin(inhibitor of prostaglandin synthase). CONCLUSION: The exciting effect of Yuanhua on un-pregnant rats in vitro might be related to an action on the cell membrane Ca2+ channel as well as to a partial stimulation of synthesis and release of PG.

Animals↗

PubMed1998

[Three cases of Dieulafoy's disease].

OBJECTIVE: To increase the knowledge of Dieulafoy's disease and decrease the misdiagnosis rate. METHOD: Three cases of Dieulafoy's disease were analyzed clinically and their therapeutic methods were discussed. RESULT: Subtotal gastrectomy including the lesion is better than other methods. CONCLUSION: It is necessary to understand the clinical pattern and pathological characteristics in order to increase the diagnosis rate and decrease misdiagnosis rate. Subtotal gastrectomy or wide wedge resection of the lesion is recommended.

Fatal Outcome↗

PubMed1998

[Expression of P27 protein in odontogenic tumors].

The expression of P27 protein was investigated in 40 cases of odontogenic tumors by immunohistochemical S-P assay. The results showed that P27 expression varied in different types of odontogenic tumors. Positive signals were present in 17/20 (85.0%) of the malignant odontogenic tumors, but in 6/20 (30.3%) of the benign ones (P < 0.005). It was suggested that P27 protein had certain practical value in the differentiation diagnosis of odontogenic tumors.

Ameloblastoma↗

PubMed1998

[Preliminary studies on pharmacological actions of tongca and xiao-tongcao polysaccharides].

OBJECTIVE: To study and compare the immunologic function and antioxidative effect of Tongcao(Tongtuomu) and Xiao-Tongcao(Ximashanjingjiehua, Xinanxiuqiu, Ditanghua) polysaccharides. METHOD: Mice were abdominally administrated with four kinds of polysaccharides at dosages of 80 mg/kg and 40 mg/kg for 7-10 days. RESULT: Four kinds of polysaccharides could increase the serum-lysozyme activity, phagocytic function of MPS and the serum hemolysin-antibody level in mice, inhibit the delayed hypersensitivity induced by DNCB in mice and raise the serum-catalase activity in mice. CONCLUSION: Four kinds of Tongcao or Xiao-Tongcao polysaccharides have immunoregulative function and antioxidative effect. The results could enrich the contents of "A Study on Species-Sorting and Quality of Tongcao-Xiao-Tongcao Crude Drugs".

Adjuvants, Immunologic↗

PubMed1998

[Hepatitis B virus and hepatocellular carcinoma].

Hepatitis B is a very important public health problem. Epidemiologic studies have shown a relationship between the hepatitis B virus (HBV) chronic carrier state and the development of hepatocellular carcinoma. HBV belongs to the Hepadna viruses family which includes the woodchuck hepatitis virus (WHV), Woodchucks infected with WHV represent a good experimental model to study the viral oncogenesis. In 85% of the studied cases, WHV acts by insertional mutagenesis in a gene of the myc family, mostly the N-myc2 gene. Expression of the myc genes is increased, suggesting the role of the viral enhancer. Study of transgenic mice have shown the liver specificity of the WHV action. In man, the liver oncogenesis is not explained. Studies are in progress to detect inactivation of tumor suppressor genes.

Animals↗

PubMed1998

[Induction of antitumor immune response by NK-cell-sensitive target cells transfected by B7-1 gene].

OBJECTIVE: To investigate whether the expression of B7-1 is involved in NK cell activation. METHODS: B7-1 gene was transfected into K562 cell line (a sensitive target cell of NK cell, without MHC class I expression) by electropolation. Specific cytotoxicity of NK cells to B7+K562 cell was assayed by 4-h Cr release assay. The proliferation of NK cells induced by B7+K562 cell was analysed by Flow Cytometry. Expansion of NK cells and cloning of NK cells were performed by mixed lymphocyte-tumor cultures and limiting dilution analysis. Production of TNF-A, GM-CSF and IFN-A was detected by ELISA tests. RESULTS: The cytotoxicity of NK cells to B7+K562 cell could be induced and that the number of NK cells could be increased by stimulation with B7+K562 cells, in particular, further enhanced with biotherapeutic agent such as OK432 and IL-2. Also, NK cell clones were established. Cytokines such as TNF- A, INF- A and GM-CSF were detected in the supernatant produced by NK cell clones. In addition, culture of lymphocytes in the presence of supernatant produced by NK cell clones and tumor antigens resulted in an increased autologous tumor killing(ATK). CONCLUSION: These findings suggest that K562 cells transfected by B7-1 gene may elicit a series of antitumor immunity and these cells may be used for further development of therapeutic tumor vaccine.

B7-1 Antigen↗

PubMed1997

Expression of calmodulin and calmodulin binding proteins in rat fibroblasts stably transfected with protein kinase C and oncogenes.

Molecular mechanisms leading to elevated calmodulin (CaM) expression in cancer have not yet been discovered. We have quantitated the levels of transcripts derived from all three CaM genes in a variety of the same origin rat fibroblasts transformed with oncogenes in combination with gene for protein kinase C using Northern blot analysis with three CaM gene specific cDNA probes. Five species of CaM mRNA were detected in all these cells. Surprisingly many of the investigated cell lines exhibited a decreased content of all CaM mRNAs as compared to control cells with CaMI and CaMII transcripts showing the most pronounced alterations. In contrast, CaM protein levels were increased in all these cell lines as determined by a radioimmunoassay. These results suggest that oncogenic up-regulation of CaM synthesis takes place posttranscriptionally. Several CaM binding proteins were found at different concentrations in the studied cell lines depending on the oncogenes used for transformation. However, CaM overexpression does not seem to affect the overall levels of CaM binding proteins.

Animals↗