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Biomedical subjects

D Yan

Publications and source records attributed to D Yan.

102 records · Page 6Linked to original sources

Correlation between serotonergic measures in cerebrospinal fluid and blood of subhuman primate.

The relationship between the concentration of serotonin (5-hydroxytryptamine; 5-HT), its precursor; tryptophan (Trp) and the main metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) and blood of monkey have been studied. 5-HT, Trp and 5-HIAA underwent circadian changes in both CSF and blood. Significant correlations were found between 5-HT, 5-HIAA and Trp in CSF and blood. The significance of these findings and their relationship to the use of peripheral serotonergic system as a functional model of the central nervous system are discussed.

Animals↗

Serotonergic measures in blood and brain and their correlations in rats treated with tranylcypromine, a monoamine oxidase inhibitor.

Tranylcypromine, a monoamine oxidase inhibitor, was administered to male Wistar rats in order to investigate its effects on blood and brain serotonin related substances after 1, 4, and 24 h following injection and possible relations between serotonergic measures in central nervous system and periphery. The dose of the drug tested was responsible for an increase in blood serotonin with a simultaneous fall in its metabolite 5-hydroxyindoleacetic acid (5-HIAA) compared to either pretreatment or control values. These changes were the most marked after 4 and 24 h following tranylcypromine injection. Almost all brain areas studied (cerebellum, medulla, hypothalamus, striatum, midbrain, hippocampus, and cortex) were to be affected by monoamine oxidase inhibitor treatment. They exhibited a rise in serotonin content starting from 1 h after drug administration and lasted in many parts of the brain up to 24 h, which was accompanied by a parallel fall in 5-HIAA level. All these changes were significant when compared to baseline and control values. Alterations in blood serotonin correlated positively with changes in brain serotonin and negatively with brain 5-HIAA, while the opposite pattern of correlations was found regarding blood 5-HIAA and the content of serotonin and 5-HIAA in various brain areas studied. This pattern of correlations speaks in favor of an existence of mutual relations between blood and brain serotonin related substances. Our results suggest that blood serotonin and 5-HIAA may serve as an index of monoamine oxidase inhibitor action on the central serotonergic system.

Animals↗

Interleukin-2-responsive wound-infiltrating lymphocytes in surgical adjuvant cancer immunotherapy.

Wound-infiltrating lymphocytes (WIL) were assessed in murine models of localized sarcoma and carcinoma to evaluate the role of interleukin-2 (IL-2)-responsive lymphocytes in adjuvant immunotherapy. Following tumor resection, IL-2 or diluent was injected at the surgical site for 6 days. Surgical site tissues were harvested and digested in a triple enzyme mixture, and single cell suspensions were prepared. Thy 1.2+ lymphocytes were isolated by incubating cells with monoclonal anti-Thy 1.2 antibody-coated magnetic beads. Lymphocyte-bead complexes were extracted with a magnet and cultured in medium containing IL-2 (100 units/ml) for 1-3 weeks. Perioperative IL-2 immunotherapy led to a three- to four-fold increase in WIL yield. WIL from IL-2-treated mice also demonstrated enhanced cytolysis of the autologous tumor and bound to activated endothelial cells with greater avidity than did the controls. We conclude that perioperative IL-2 therapy augments the yield, as well as the cytolytic and adhesive properties, of wound-infiltrating lymphocytes.

Animals↗

Relationship between serotonergic measures in periphery and the brain of mouse.

Circadian rhythm and the relationship between the concentration of serotonin (5HT) and related substances (5-hydroxyindoleacetic acid; 5HIAA and tryptophan; Trp) in mouse brain, stomach and blood have been studied. All factors underwent circadian changes in the brain and blood. 5HT and 5HIAA levels in the stomach showed no circadian fluctuation. The concentrations of 5HT in the brain and blood did not correlate. Significant correlations were found between other serotonergic parameters analyzed in brain, stomach and blood. A significant negative correlation was observed between brain 5HIAA and blood 5HIAA. The concentration of tryptophan in the brain was correlated with the plasma total tryptophan level. There was fairly significant correlation (p less than 0.06) between brain serotonin and plasma tryptophan levels. The brain serotonin and tryptophan levels were strongly correlated (R = 0.410, p less than 0.03). Significant negative correlation was found between serotonin in the blood and serotonin in the stomach as well as between its level in the brain and in the stomach. The significance of these findings and their relationship to the use of peripheral serotonergic system as a model of neurons are discussed.

Animals↗

[Primary analysis on hypertension community control in East City].

In order to carry out chronic disease prevention, a hypertension community control program has been conducted in Disease Surveillance Point, East City. Beijing since 1989. The resident committees were randomly divided into two groups. The community control activities were conducted in intervention group, which included home visit, health education. 3190 hypertensive cases were managed in 1991. Current smoking rate was decreased 8.37%, quit and reduce smoking increased 5.81%, drinking decreased 8.77%, reduced salt intake 5.45%, DBP < 95 mmHg increased 27.81%, when compared with base line survey in 1989. These indicators were significant between intervention and control groups. It means hypertension community control program is successful.

China↗

Marek's disease virus gene clones encoding virus-specific phosphorylated polypeptides and serological characterization of fusion proteins.

Marek's disease virus (MDV) gene clones, RA2 and GA8, constructed in E. coli bacteriophage lambda-gt11 (gt11) were identified by a monoclonal antibody (MAb), H19.47, against a putative transformation-related viral antigen consisting of a complex of three phosphorylated polypeptides, pp41, pp38, and pp24. Both recombinants have a MDV-DNA insert of about 0.5 kb and are mapped to the region of BamHI-H or EcoRI-X fragments of the MDV genome by Southern blot hybridization. Immunoblot and immunoprecipitation with H19.47 identified a recombinant beta-galactosidase-MDV 140-kD fusion protein for RA2 and a 127-kD fusion protein for GA8. Immunoprecipitation of 35S-methionine-labeled, MDV-infected chicken embryo fibroblasts (CEF) with antisera against RA2 and GA8 fusion proteins recognized five polypeptides, of which three (p41, p38, and p24) are specified by H19.47 and the remaining two, p135 and p20, have not been previously identified. Immunoprecipitation of 32P-phosphate-labeled or 3H-glucosamine-labeled, GA-MDV-infected CEF with the antiserum against RA2 fusion protein identified a phosphorylated polypeptide of 38 kD and two glycoproteins of 60 and 49 kD, respectively. The antisera against recombinant fusion proteins thus revealed the existence of epitopes common to the phosphorylated polypeptides and other MDV-specific polypeptides. Sera from chickens or mice hyperimmunized with the purified fusion proteins reacted with serotype 1, MDV-infected CEF in the fluorescent antibody (FA) test to significant titers. These immune sera did not react with either serotype II or III, indicating the serotype specificity of the phosphorylated polypeptides.

Animals↗

Studies on immunopathogenesis in epidemic hemorrhagic fever: sequential observations on activation of the first complement component in sera from patients with epidemic hemorrhagic fever.

Sequential measurements of activation of the 1st component of complement (C1) in the sera of 29 patients hospitalized with epidemic hemorrhagic fever (EHF) were performed according to a method recently developed. These patients were treated with supportive, routine therapy, but not immunosuppressive agents. This paper describes the kinetic observations on the activation of C1 in the 29 cases. The data confirm that an apparently increased extent of activation occurred in their sera. It was found that the more severely ill the patients were, the more apparent the activation. Additionally, beginning with the 15th day of disease, the extent of C1 activation diminished in most of the moderate and severe types of patients, but not in those with moribund illness and fatal ones. On the basis of the study, it may be reasonably concluded that C1 activation was correlated well with the severity and clinical course of EHF, indicating that the classical C pathway was activated in these patients. We feel that our findings are important to an understanding and elucidation of the immunopathogenetic mechanisms of EHF.

Adolescent↗