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Biomedical subjects

T C Tung

Publications and source records attributed to T C Tung.

At least 55 records · Page 3Linked to original sources
PubMed1982

Immunologic evaluation of patients with polychlorinated biphenyl poisoning: evaluation of delayed-type skin hypersensitive response and its relation to clinical studies.

Polychlorinated biphenyl (PCB) poisoning causes many physiological abnormalities including immune suppression. Cellular immunity was studied in 30 PCB-poisoned patients and 50 normal human subjects. PCB poisoning caused suppression of cellular immunity such as the delayed-type skin response to streptokinase and streptodornase. The suppression of cellular immunity was correlated with the severity of the disease. Thus evaluation of the immune function may be helpful for the diagnosis of PCB poisoning.

Adolescent↗
PubMed1982

Inhibitory effects of four isoabrins on the growth of sarcoma 180 cells.

The four isoabrins were shown to be capable of inhibiting the growth of tumor cells in vivo when one-fifth of their median lethal dose was used. From the in vitro experiments, the doses required for 50% inhibition of protein biosynthesis are 3.2 pg, 45 ng, 32 ng, and 10 ng/ml for abrin-a, -b, -3, and -d, respectively. Except for abrin-b, a good correlation between the inhibitory effects of abrins on the tumor growth and protein biosynthesis was observed. These isoabrins show a moderate inhibitory effect on DNA biosynthesis.

Abrin↗
PubMed1982

Induction of antitumor immunity by tumor cells treated with abrin.

Abrin is known as a cytotoxic lectin. Immunization with Meth-A tumor cells which were treated in vitro with abrin induced a strong antitumor immunity in syngeneic BALB/c mice. The immunizing effect was stronger than that produced by an irradiated Meth-A tumor cell vaccine. Studies on the mechanisms of the immunizing effect with the abrin-treated tumor cells demonstrated that abrin acts as an immunoadjuvant. Furthermore, the regression of a growing Meth-A tumor was observed after abrin was injected into the tumor, while the induction of a strong antitumor immunity also occurred. It appears, therefore, that the antitumor effects of abrin are attributable to two kinds of activity: cytotoxicity and adjuvant activity.

Abrin↗
PubMed1981

Lectin derivatives of methotrexate and chlorambucil as chemotherapeutic agents.

Methotrexate and chlorambucil, each covalently linked to either abrus agglutinin, abrin, ricinus agglutinin, ricin, or concanavalin A, were prepared. A single dose of the derivative injected ip into sarcoma 180-bearing noninbred N:NIH(S) white mice resulted in prolongation of the survival time and was more effective than an equivalent dose of free drug and lectin. Drug-lectin also showed a higher inhibitory effect on the DNA biosynthesis of the tumor cell than did an equivalent dose of the free drug and lectin.

Abrin↗
PubMed1980

Studies on patients with polychlorinated biphenyl poisoning. 2. Determination of urinary coproporphyrin, uroporphyrin, delta-aminolevulinic acid and porphobilinogen.

Urinary excretion of heme precursors were evaluated in 69 human subjects who have consumed rice oil contaminated with polychlorinated biphenyls (PCBs). Twenty four hour urinary samples were collected from 20 normal healthy volunteers and 69 PCB poisoned human subjects and assayed for the concentrations of delta-aminolevulinic acid, prophobilinogen, uroporphyrin and coproporphyrin. PCB poisoning caused an increased excretion of delta-aminolevulinic acid (from 0.72 mg/24 hours to 1.00 mg/24 hours) and uroprophyrin (from 13.6 micrograms/24 hours to 41.2 micrograms/24 hours), but not the excretion of porphobilinogen (0.34 mg/24 hours) or coproporphyrin (30 micrograms/24 hours). The excretion pattern of urinary heme precursors associated with PCB poisoning is different from those due to lead or arsenic poisoning. The analysis of urinary heme precursors may be helpful for screening patients with PCB poisoning.

Aminolevulinic Acid↗