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Biomedical subjects

Y X Chen

Publications and source records attributed to Y X Chen.

At least 19 recordsLinked to original sources
PubMed1991

Glomerular macrophage proliferation in experimental immune complex nephritis.

In immune complex nephritis, glomerular hypercellularity is known to result from the proliferation of intrinsic cells and from the infiltration of mononuclear cells, primarily macrophages. An immunohistochemical double-labeling procedure was used to determine whether macrophages were among the cells which may undergo mitosis within the glomerular tuft. The monoclonal antibody ED1 served as a macrophage marker; cells in the S-phase of mitosis were recognized by uptake of bromodeoxyuridine. Glomerular proliferation was studied in chronic serum sickness of LEW rats, an animal model of immune complex nephritis for which the relationship between immunopathology and pathophysiology has been well described. In normal glomeruli, resident mesangial macrophages accounted for an unexpectedly large proportion (greater than or equal to one-third) of the total mitotic activity. In immune complex glomerulonephritis, the rate of glomerular macrophage proliferation increased rapidly just at the onset of proteinuria and remained high throughout the remaining course of disease. Glomerular macrophages from rats with proliferative nephritis also divided more vigorously than normal in short term culture in vitro, while persistently expressing abnormal surface marker phenotypes. The proliferation of mesangial macrophages appears to be a prominent feature of the normal process of glomerular cell renewal. In hypercellular glomeruli, vigorous local proliferation could greatly amplify the potential of macrophages to cause damage.

Animals↗
PubMed1991

[Prediction and prevention of hypertension syndrome of pregnancy].

Analysis of mean artery pressure (MAP-2) according to the differentiation of symptom complex of TCM can predict the occurrence of hypertension syndrome of pregnancy (HSP) at patients' first visit to hospital during their middle gestational period (less than 24 pregnant weeks). 424 pregnant women (MAP-2 greater than or equal to 12kPa) were divided into 4 groups and given preventive treatment as follows: (1) The control group, 122 women, no drugs were given; (2) the Theragan group, 102 women; (3) the TCM (A) group, 100 women, those with Liver-Kidney deficiency of Yin or no apparent signs were given Qiju Dihuang Wan, and those with Spleen-Kidney deficiency of Yang were given Shenqiwan; (4) the TCM(B) group, 100 women, were given Salvia miltiorrhiza plus (A) group's drugs. The results of prediction: (1) The occurrence rate of HSP in the MAP-2 less than 12kPa group was 10. 5%; in the MAP-2 greater than or equal to 12kPa group, 49.2%. The difference was significant. (2) The rate of deficiency of Yin in the MAP-2 greater than or equal to 12kPa was significantly higher than in the MAP-2 less than 12kPa. The rate of HSP in the deficiency of Yin was higher than in the nondeficiency of Yin. The rate of HSP increased to 70. 7% in the MAP-2 greater than or equal to 12kPa with deficiency of Yin. The results of prevention: (1) The occurrence rates of HSP in 4 groups were 49.2%, 30.4%, 15% and 14% respectively. (2) There was no side effect for mother and infant after preventive treatment. No eclampsia occurred.

Drugs, Chinese Herbal↗
PubMed1990

Activation of a membrane-associated phosphatidylinositol kinase through tyrosine-protein phosphorylation by naphthoquinones and orthovanadate.

We have previously reported that several naphthoquinones stimulated tyrosine-specific protein phosphorylation in isolated rat liver membranes. Our more recent study demonstrated a similar effect by orthovanadate, which concomitantly stimulated phosphorylation of protein-tyrosine and phosphatidylinositol (Ptd-Ins). Results presented here show a simultaneous increase in PtdIns phosphorylation along with stimulation of tyrosine-protein phosphorylation by naphthoquinones. This PtdIns kinase resembles the type I PtdIns kinase in that it was insensitive to adenosine inhibition. The product, nevertheless, comigrated with a PtdIns-4-phosphate standard in TLC using three different solvent systems. Stimulation of PtdIns phosphorylation by vanadate or naphthoquinones could be achieved in the following preparations: intact rat liver membranes, Triton X-100-solubilized membranes, solubilized membranes partially purified by Sephacryl chromatography, solubilized membranes purified by wheat germ agglutinin chromatography. The naphthoquinone or vanadate-activated PtdIns kinase activity could be isolated by antiphosphotyrosine antibody-agarose affinity chromatography. The relative potencies of a series of ring-substituted naphthoquinones in the stimulation of tyrosine-protein phosphorylation, PtdIns kinase activity, dithiothreitol-dependent oxygen consumption, and cytochrome c reduction were highly correlated. We conclude that oxidant(s) produced by redox cycling of naphthoquinones stimulated an adenosine-insensitive PtdIns kinase through tyrosine phosphorylation of the enzyme.

1-Phosphatidylinositol 4-Kinase↗
PubMed1990

[Expression of interleukin 2(IL-2) receptor and proliferative response to rIL-2 of peripheral blood mononuclear cells (PBMC) in patients with malignant diseases].

Expression of IL-2 receptor and proliferative response to rIL-2 of PBMC were studied in 48 patients with malignant diseases and in 50 normal subjects. Having been activated by PHA, PBMC from cancer patients had about the same percentage of Tac positive cells as compared with the normal subjects. However, resting and Con A-activated PBMC showed a significantly weaker proliferative response to rIL-2 in cancer patients than in normal subjects (P less than 0.001-0.005). The decrease in PBMC proliferative response to rIL-2 in patients with malignant diseases might be due to a defect in the formation of high affinity IL-2 receptors.

Adult↗
PubMed1989

[Experimental study of a decoction of yiguan jian].

In this paper, the decoction of Yiguan Jian is reported to have significant fatigue-resisting, hypoxia-resisting, antiinflammatory, sedative, analgesic, extracorporal bacterio-static actions, and also to strengthen the phagocytosis of Phagocytes. Besides, the drug can antagonize acetylcholine-induced spasm of isolated intestinal muscles in rabbits. The decoction has proved safe for use. This study provides some experimental basis for clinical use in nourishing yin, invigorating the liver and treating many diseases.

Animals↗
PubMed1989

[Restriction map of E. coli shuttle plasmid (p# GTE5) with secretive function].

The shuttle plasmid (p# GTE5) DNA with secretive function was extracted by the alkali lysozyme method from E. coli RRI strain. Its molecular weight is 4.5 Md and DNA size is 6.9 Kb. Restriction fragments of plasmid was obtained by single and double enzymes complete digestion using five different restriction endonucleases. The restriction map of shuttle plasmid (p# GTE5) was established for the enzymes EcoRI, BglII, pstI, PvuII, and TaqI.

Escherichia coli↗
PubMed1989

[Influence of emotional stress and behavior during acute myocardial infarction on prognosis].

Seventeen cases of acute myocardial infarction (AMI) with emotional stress (group A) and 54 cases with basically stable emotion (group B) were compared with respect to three major complications (arrhythmia, cardiac insufficiency of grade 3 and 4 and cardiogenic shock) and therapeutic effect. The results showed that the incidences of the three complications in group A were significantly higher than those in group B (P less than 0.05), and the clinical condition was more serious in the former group. Response to narcotics showed that number of patients requiring more than 3 injections of either dolantine 50 mg or morphine 5 mg was significantly greater in group A than in group B (P less than 0.001). Sigma ST was not found to be significantly different between the two groups. However, the duration of elevation of ST segment was significantly longer in group A than in group B (P less than 0.01). It is suggested that relief of myocardial ischemia is slow in group A. There were five patients in group A with extended infarct size and died during the acute stage. None in the group B showed extension of infarction. The mortality rate in group A significantly higher than that in group B (53% VS 3.7%, P less than 0.001) and it bears no relation with sex, age and the site of infarction on admission. The greater the emotional upheaval the more unfavorable the prognosis. It is shown that excessive emotional stress is an important risk factor of AMI and aggressive measures are required to prevent worsening of the condition.

Adult↗
PubMed1988

High-resolution electron microscopic investigation of supported platinum particles reduced at high temperatures.

High-resolution electron microscopy has been used to characterize the platinum particles supported on TiO2 or ZnO. After reduction at elevated temperatures, the metallic particles display a regular, faceted shape, and several superstructures, Pt3 Ti(C), Pt3 Ti(H), PtTi, and PtZn, have been found. These results, which may involve strong metal-support interaction, have been confirmed by optical diffraction and image simulation.

Hot Temperature↗
PubMed1986

A monoclonal antibody that induces T cell aggregation reacts with vascular endothelial cells and placental trophoblasts.

We have found that a mouse monoclonal antibody (alpha Leu-13) to a 16 kilodalton human lymphocyte surface antigen reacts with vascular endothelial cells as determined by immunoperoxidase staining of frozen tissue sections. In earlier studies, alpha Leu-13 was found to induce purified T cells to aggregate when added to cultures in nanogram concentrations. In the studies reported here, alpha Leu-13 stained vascular endothelial cells of arteries, capillaries, and veins in all organs examined from adults. It also reacted weakly with epithelial cells of proximal tubules of the kidney and with nonkeratinized basal epithelial cells of the cervix and esophagus. When a panel of tissues from a 14-wk-old fetus was examined, alpha Leu-13 was not found to react with endothelial cells of any specimen. However, it did stain medullary thymocytes and placental trophoblasts of this fetus. The implications of these findings to the possible function of the Leu-13 antigen in immune ontogeny are discussed.

Antibodies, Monoclonal↗
PubMed1986

Gene products of the HLA-D region in normal and malignant tissues of nonlymphoid origin.

Indirect immunofluorescence staining with monoclonal antibodies has shown a differential distribution of HLA-DR, DQ, and DP antigens in normal tissues of nonlymphoid origin. The distribution of HLA-DP antigens is similar to that of HLA-DR antigens, while that of HLA-DQ antigens is more restricted. Malignant transformation of cells of nonlymphoid origin may be associated with the appearance of the gene products of the HLA-D region. HLA-DR antigens appear more frequently than the other two types of HLA class II antigens and HLA-DP antigens more frequently than HLA-DQ antigens. Differential expression of the gene products of the HLA-D region was also found in autologous metastases removed from different anatomic sites from patients with melanoma. The HLA class II phenotype of surgically removed malignant lesions did not correlate with the degree of differentiation of tumor cells and/or with the expression and/or cellular distribution of HLA class I antigens. Furthermore, in melanoma lesions, no relationship was found between the HLA class II phenotype and the expression of 3 membrane bound and 1 cytoplasmic melanoma associated antigen recognized by monoclonal antibodies. The functional significance and the practical implications of the differential expression of the gene products of the HLA-D region by tumor cells are discussed.

Antibodies, Monoclonal↗
PubMed1986

Identification with the monoclonal antibody 26.163 of a determinant shared by the beta chains of the gene products of the HLA-DR, DQ, and DP loci.

Immunochemical studies (sequential immunoprecipitation followed by SDS-PAGE and two-dimensional gel electrophoresis) have shown that the monoclonal antibody (MoAb) 26.163 reacts with HLA-DR, DQ, and DP antigens. Testing with isolated alpha and beta chains of HLA class II antigens and immunoblot analysis also demonstrated that the determinant defined by the MoAb 26.163 is localized on beta chains and does not require their association with alpha chains for its expression. The MoAb 26.163 appears to be the first example of a monoclonal antibody with specificity for the gene products of HLA-DR, DQ, and DP loci.

Antibodies, Monoclonal↗