Search PubMed⌕ Search

Biomedical subjects

T M Zhang

Publications and source records attributed to T M Zhang.

At least 55 records · Page 3Linked to original sources
PubMed1991

Interruption study of viremia of patients with hemorrhagic fever with renal syndrome in the febrile phase.

Kinetic changes of viremia were observed in 287 cases of hemorrhagic fever with renal syndrome (HFRS) in whom ribavirin was administered with double blind random control studied by means of virus isolation, indirect immunofluorescence assay and enzyme-linked immunosorbent assay. The positive rate of viremia was 79.7% (Sp = 3%) and positive rate of HERS IgM was 85% (Sp = 3.1%) before treatment. Viremia could be interrupted by ribavirin as in the ribavirin treated group, the viremia positive rate decreased, duration of viremia was shortened, viral antigen products, virus titer and HFRS IgG antibody level were reduced as compared with the control group. This showed that viremia was very frequent in patients in the febrile phase and ribavirin is an effective antiviral drug in HFRS during the febrile phase. Dosage and course of treatment of this drug are discussed.

Double-Blind Method↗
PubMed1991

[Scavenging of probimane on semiquinone free radical formation by doxorubicin in rat heart].

Probimane, dl-bis (4-morpholin-methyl 3,5-dioxopipweazin-1-yl) propane first synthesized in China, is a dioxopiperazin compound with antineoplastic, antimetastatic and radiopotentiating activities. In order to evaluate the mechanisms of cardiotoxicity protective action of probimane, the free radical induced by doxorubicin were analysed by electron spin resonance (ESR) techniques. Our studies showed that doxorubicin stimulated the formation of semiquinone free radicals in the rat heart homogenate and heart cell mitochondria systems, and probimane inhibited the free radical formation in both systems, with the dose-dependent and time-dependent responses. The inhibitory rates of doxorubicin free radical formation in rat heart homogenate system by probimane 0.6 mmol.L-1 at time of 3, 5, 10, 15, 30, 45 and 60 min were 44.6%, 43.0%, 51.5%, 74.3%, 68.1%, 56.1% and 39.9% respectively. The inhibitory rates of semiquinone free radical formation in mitochondria system by probimane at the concentration of 0.02, 0.06, 0.6, 1.2 and 2.4 mmol.L-1 were 17.07%, 29.87%, 63.95%, 64.62% and 83.64%, respectively. Probimane had no effect on NADH2, but inhibited NADH dehydrogenase activity at higher concentration.

Animals↗
PubMed1990

Immunological phenotypes of twelve cases of nonepidermotropic cutaneous T-cell lymphoma.

The immunologic phenotypes of 12 cases of nonepidermotropic cutaneous T-cell lymphoma are reported. All cases consisted of mature peripheral T-cells. There were 9 cases of helper T-cell (Th) phenotype and 2 cases of suppressor T cell (Ts) phenotype. One case, however, expressed both the Th and Ts phenotypes. Two separate cases displayed OKT9 positivity. OKT6 positive lymphoid cells were found in the dermis during the early and late stages of the disease. We suggest that these OKT6 positive cells should represent a dermal infiltrate of Langerhans cells of immature T-cells.

Adolescent↗
PubMed1990

[Effects of triptolide on T lymphocyte functions in mice].

Triptolide (Tri) is an active principle of Tripterygium hypoglaucum Hutch, which has been used to treat cancers and autoimmune diseases in folk medicine. The lymphocyte proliferation (LP) induced by Con A or Lipopolysaccharide (LPS) was suppressed by Tri at 50 and 500 ng/ml. At 5 ng/ml the suppressive effect on LP induced by Con A was much stronger than that by LPS. The humoral immune reaction monitored by quantitative hemolysis spectrophotometry (QHS) was suppressed by Tri 0.75 and 1 mg/kg ip. IL-2 production by mouse spleen cells were suppressed by Tri 5, 50,500 ng/ml in vitro and 0.5, 0.75 and 1 mg/kg ip. IL-2 activity was assayed by assessing its ability to support proliferation of selected IL-2-dependent T cell line, measured by colorimetric method which is based on the ability of viable cells to cleave MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide). Ts cells induced by supraoptimal immune (SOI) were suppressed by Tri 0.5 and 0.75 mg/kg ip. These results suggest T or its subpopulations and B lymphocytes may be the target cells of Tri.

Animals↗
PubMed1989

[Scavenging effects of probimane on active oxygen free radicals by electron spin resonance].

Probimane, dl-1,2-bis (4-morpholine-methyl-3, 5-dioxopiperazin-1-yl) propane, is a new antitumor agent synthesized by Shanghai Institute of Materia Medica, Chinese Academy of Sciences. The scavenging effects of probimane on active oxygen radicals produced in 3 different systems were studied with the ESR spin trapping methods. In Fenton's reaction, probimane remarkably scavenged hydroxyl radicals (.OH) and the rate of scavenging .OH by probimane 0.05 mmol/L was 47%, compared to 5% by vitamin E (VE) and 30% by ascorbic acid (AA). In irradiation riboflavin system, in which superoxide (O2-.) was produced, the agent also had the scavenging effects on O2(-.). The rate of scavenging O2-. by probimane 0.05 mmol/L was 13%, higher than that by VE (7%) but lower than that by AA (90%). In cell system where the active oxygen radicals were produced during the respiratory burst of human neutrophils (Neu) stimulated by TPA (tetradecanoylphorbol acetate), probimane exhibited a dose-dependent scavenging action on the radicals. The rate of the radical scavenging by probimane 0.05 mmol/L was 37%, much higher than that by VE (9%) but lower than that by AA (68%). Probimane had no effect on the rate of oxygen consumption by human Neu, measured with spin probe oxymetry.

Antineoplastic Agents↗
PubMed1989

[Observation on the distribution of [14C] AT-1902 in mice].

Distribution of [14C] AT-1902 in mice was studied by means of whole body autoradiography. After [14C] AT-1902 was injected im to mice, radioactivity was rapidly taken up by various organs. The highest radioactivity was found in kidneys, then the liver, lung, tumor and skin etc. Lowest radioactivity was found in brain. It is suggested that [14C] AT-1902 may be excreted through the gastrointestinal tract and kidneys.

Animals↗
PubMed1989

[Action of schizandrin B, an antioxidant, on lipid peroxidation in primary cultured hepatocytes].

The action of schizandrin B (Sin B) was observed in freshly isolated hepatocytes damaged by FeSO4/cysteine and CCl4. Two types of free radicals, .OH and .CCl3, generated from FeSO4/cysteine and CCl4, respectively, induced lipid peroxidation in hepatocytes. It was found that the speed of lipid peroxidation (MDA production) and the degree of alteration in hepatocyte morphology were closely related to the type of free radicals. MDA production and membrane protrusion of hepatocytes injuries by FeSO4/cysteine were faster and more severe than those observed with CCl4. Sin B was shown to decrease the production of MDA and the release of GPT and LDH, and to increase hepatocyte viability as well as maintaining the integrity of the hepatocyte membrane surface. These actions of Sin B were stronger than vitamin E at the same concentration. It was observed that no inhibitory effect of phenobarbital, a typical inducer of cytochrome P-450, as Sin B induced liver cytochrome P-450, on MDA production in hepatocytes damaged by FeSO4/cysteine. The results suggest that Sin B possesses antioxidant activity.

Animals↗
PubMed1988

Morphological changes in locus ceruleus of albino rats in relation to aging.

Comparative studies were carried out under light, fluorescence- and electron-microscopic observations between young, adult and aged groups of albino rats with the following results: the neuronal packing density of locus ceruleus decreases with advanced age. In addition to the senescent loss of nerve cells, the surviving ones showed some shrinkage of perikarya and reduction or loss of Nissl substance. Some of them presented pyknosis, chromatolysis and loss of RNA in cytoplasm. Glial cells proliferated around the degenerating cells. Senescent cells showed an increase of heterochromatin and decrease of euchromatin. Changes in cytoplasmic organelles included the decrease of ribosomes, alterations in mitochondria and increase of lipofuscins. These senescent changes were thought to affect the absorption of nutrition, message exchange, protein synthesis, supply of energy and transport of materials by the nerve cells.

Aging↗