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Biomedical subjects

Y Kuroda

Publications and source records attributed to Y Kuroda.

At least 937 records · Page 52Linked to original sources

Exacerbation of myasthenia gravis after removal of a thymoma having a membrane phenotype of suppressor T cells.

We describe a case of myasthenia gravis associated with a thymoma having a membrane phenotype of suppressor T cells, as defined by monoclonal antibodies. Thymectomy resulted in exacerbation of the disease, a drastic increase in serum acetylcholine receptor-antibody titer, and a decrease of the circulating suppressor T cell population. The findings indicate that the etiopathogenic relationship between the thymus and myasthenia gravis is variable and complex.

Adult↗

A case report of glomus tumor of the stomach.

A case of glomus tumor of the stomach and a brief review of the literature are reported. As the neoplasm may be benign, extensive surgery should be avoided in the absence of a precise diagnosis.

Aged↗

Cystic lymphangioma of the colon. Report of a case and review of the literature.

A rare case of cystic lymphangioma of the colon is reported. The lobulated and fluctuant lesion was located in the splenic flexure and was associated with multiple adenomas in the entire colon. Well differentiated adenocarcinomas restricted to the mucosal layer were also demonstrated in two of the adenomas of the colon. Clinical features, appropriate treatment, and possible pathogenesis of colonic lymphangioma are discussed.

Adenoma↗

Ganglioside composition of chromaffin granule membrane in bovine adrenal medulla.

The ganglioside composition of chromaffin granule membranes of bovine adrenal medulla was investigated. Two major gangliosides, which accounted for over 95% of total gangliosides, were characterized as GM3 (NeuAc) and GM3 (NeuGc) by thin layer chromatography (TLC) and gas-liquid chromatography (GLC). Chromaffin granule membranes contained a relatively higher concentration of gangliosides than the membranes of other subcellular organelles; three times higher than microsomal membranes and seven times higher than mitochondrial membranes. This high concentration of ganglioside in chromaffin granule membranes could contribute to the high concentration of gangliosides in the adrenal medulla as compared to other extraneural tissues.

Adrenal Medulla↗

Immune interferon production by TH69, a lyophilized preparation of Streptococcus faecalis, in murine spleen cell cultures.

In mouse spleen cell cultures, TH69, a live Streptococcus faecalis (ATCC 31663) preparation, at a concentration of 20 micrograms/ml induced immune interferon (IFN gamma) with molecular weight ranging from 20,000 to 40,000 daltons together with a small amount of IFN alpha/beta. By using nonsensitized mouse spleen cells, the fact that both T-cells and macrophages are required for this IFN production was established. When these spleen cells were obtained from mice sensitized 12 days earlier with 4 mg of TH69, twice as much IFN was produced than in cells obtained from nonsensitized mice. This increase was explained by the presence of both sensitized macrophages and T-cells in a reconstitution experiment.

Animals↗

Participation of macrophages in enhanced in vitro immune interferon (IFN gamma) production with mouse spleen cells.

IFN gamma production in cultures of spleen cells obtained from mice sensitized with TH69, a live Streptococcus faecalis preparation, was examined to determine how macrophages participate. It was demonstrated that sensitized spleen macrophages participated in enhanced IFN gamma production by T cells at an early stage (0-6 hr) of incubation, and that this production is mainly dependent on Ia-bearing macrophages In the reconstitution experiments where different combinations of spleen macrophages and T cells obtained from mice sensitized with TH69, OK-432, and BCG were used, T cells required that the identity between the sensitizing organisms in vivo and the stimulating organisms in vitro be the same for enhanced IFN gamma production while macrophages did not. Macrophage-mediated production of IFN gamma appears to be genetically restricted because IFN gamma was only produced in cultures where the H-2 region of macrophages and T cells matched. Further examination revealed that for macrophages to participate in enhanced IFN gamma production, first contact between cycloheximide-treated macrophages and T cells was required. Second, enhanced IFN gamma production occurred when culture supernatants of macrophages obtained from sensitized spleen cells were added to T cells. However, the addition of culture supernatant obtained from sensitized peritoneal macrophages resulted in inhibition of IFN gamma production. These results clearly showed the crucial role of macrophages in enhanced IFN gamma production by spleen T cells in vitro.

Animals↗

Cytidine 5'-diphosphate reductase and thymidine kinase activities in phytohemagglutinin-stimulated lymphocytes of normal subjects of various ages and patients with immunodeficiency.

The activities of CDP reductase and thymidine kinase in 10(6) to 5 X 10(6) phytohemagglutinin (PHA)-stimulated lymphocytes isolated from 2 to 5 ml of peripheral blood of individual subjects were measured. The activities of CDP reductase (pmol/h/10(7) cells) and thymidine kinase (nmol/h/10(7) cells) were high in infants, 698 +/- 307 and 64.2 +/- 20.2, constant in subjects of 1-40 years old, 401 +/- 181 and 38.1 +/- 15.3, and low in persons of more than 80 years old, 121 +/- 113 and 22.3 +/- 17.8, respectively. The ratio of thymidine kinase to CDP reductase activity increased with age, indicating that dependency on the salvage pathway of DNA synthesis in lymphocytes increased with age. The activities of CDP reductase and thymidine kinase were reduced in patients with the hyperimmunoglobulin E syndrome, congenital cytomegalovirus infection, anhidrotic ectodermal dysplasia with hyperimmunoglobulin A, Bloom's syndrome, immunodeficiency with hyperimmunoglobulinemia, and Down's syndrome. The clinical symptoms of these diseases seem to be due to impaired DNA synthesis of PHA-stimulated lymphocytes, but the degrees of reduction of enzyme activities were generally greater than that of thymidine incorporation in these patients.

Adolescent↗

Effects of dichloroacetate on pyruvate metabolism in rat brain in vivo.

The effects of dichloroacetate (DCA) on the activity of the pyruvate dehydrogenase (PDH) complex and associated changes in the lactate and glucose levels in rat brain were investigated in vivo. The average activities of the active form of the PDH complex in the brain, liver and muscle of starved rats were respectively 0.40 +/- 0.04, 0.07 +/- 0.04, and 0.17 +/- 0.11 mumol/min/g tissue, and amounted to 21, 11, and 16% of the total activity of the complex. Intraperitoneal injection of DCA (125 mg/kg) increased the percentage of the active form of the PDH complex in the brain, liver, and muscle to 107, 40, and 84%, respectively. DCA significantly lowered the lactate and glucose concentrations of the brain and blood. A lower dose of DCA (12.5 mg/kg) also caused significant increase in activity of the PDH complex in the brain, but did not significantly change the lactate or glucose concentration of the brain. These results suggest that DCA crosses the blood-brain barrier reasonably well.

Acetates↗

[Computed tomography for the diagnosis of a renal mass].

The accuracy of differential diagnosis of renal mass lesions by computed tomography (CT) was evaluated. A retrospective study was done on 23 patients with renal mass lesion suspected by conventional IVP. Cases studied included 6 renal cell carcinomas, 1 nephroblastoma, 2 transitional cell carcinomas of renal pelvis, 3 parapelvic cysts, 2 polycystic kidneys and 9 other benign renal lesions. CT, especially with enhancement, is advantageous for evaluation of the extent of the tumor and also for the differentiation between cystic and solid masses by their attenuation. However, angiography and venography could provide valuable information for surgery of malignancy; and, retrograde pyelography also would help in assessing the extent of tumor spread in the renal pelvis. Two of our cases of parapelvic cyst and a case of renal bleeding could not be distinguished accurately by CT. Sonography or other diagnostic procedures might be helpful in such cases.

Adenocarcinoma↗

Ribonucleotide reductase and thymidine kinase activities in various cultured cell lines derived from hematologic malignancies.

The activities of ribonucleotide reductase and thymidine kinase, and the thymidine incorporation rate were measured in 16 cultured human hematologic malignant cell lines with different cell proliferation rates. Thymidine kinase activity was significantly higher in myeloid and monocytoid cell lines than in other cell lines, but ribonucleotide reductase activity presented as CDP reductase activity was similar in the different cell lines. The ratio of thymidine kinase to CDP reductase activity was high in monocytoid cell lines. A close correlation was found between the cell proliferation rate and CDP reductase activity, but not thymidine kinase activity or the thymidine incorporation rate. The ratio of thymidine kinase to CDP reductase activity was high in slowly growing cell lines and low in rapidly growing cell lines. These results indicate that in cultured human malignant cells a high potential for proliferation may depend mainly on the de novo pyrimidine pathway of DNA biosynthesis.

Adolescent↗