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Biomedical subjects

T Koike

Publications and source records attributed to T Koike.

At least 685 records · Page 38Linked to original sources
PubMed1987

Preventive effect of monoclonal anti-L3T4 antibody on development of diabetes in NOD mice.

We analyzed the surface phenotypes of infiltrated cells in pancreases of nonobese diabetic (NOD) mice with monoclonal antibodies to mouse lymphocytes. Most of the infiltrated cells were Thy1+ and Ly1+ T-lymphocytes, and most of them were L3T4+ helper T-lymphocyte subsets. To elucidate the role of L3T4+ T-lymphocytes in the development of insulitis and diabetes in NOD mice, we treated the animals with injections of monoclonal anti-L3T4 antibody. Administration of this antibody prevented the insulitis and diabetes in NOD mice. These results lead to conclusions that the L3T4+ helper T-lymphocytes may play an essential role in the pathogenesis of type I diabetes and that the manipulation of the OKT4+ (Leu3+) T-lymphocyte subset, the human homology of L3T4, with monoclonal antibodies may provide effective therapy for human type I diabetes.

Animals↗
PubMed1987

Identification of lymphoid cell lines bearing receptors for somatostatin.

The MT-2, derived from an adult T-cell leukaemia (ATL) cell, the Molt-4F, a human T-cell line, and the Isk, an EB virus-transformed B-cell line, were found to have high-affinity receptors for somatostatin, a cyclic tetradecapeptide that inhibits the release of substances such as growth hormone, TSH, glucagon, insulin, secretin, gastrin and cholecystokinin. The quantity of radioactivity bound varied linearly with the number of cells, and was displaced by non-radioactive somatostatin in a concentration-dependent manner. Specific binding of 125I-somatostatin was time- and temperature-dependent and at 22 degrees reached equilibrium within 120 min. Scatchard analysis demonstrated one class of specific-binding sites on MT-2 cells, Isk cells and Molt-4F cells that had respective densities and dissociation constants of 109 pM and 0.64 nM, 102 pM and 1.1 nM, and 5.8 pM and 0.22 nM.

Cell Line↗
PubMed1987

Cell surface phenotyping of megakaryoblasts.

Surface phenotypic characterization of megakaryoblasts, identified by platelet peroxidase activity, was investigated in four patients who showed increased proliferation of megakaryoblasts: one patient with typical features of acute leukemia, one presenting with acute myelofibrosis, and two with Down's syndrome in whom blasts disappeared spontaneously (transient abnormal myelopoiesis, TAM). MY10 and/or MY9 antigens were expressed on the surface of some megakaryoblasts, but MY7, and MY4, antigens specific to granulocytic or monocytic cells, were not. Some megakaryoblasts were positive for only anti-HLA-DR antibodies. It was speculated that, during the differentiation of the megakaryocytic lineage, MY9 antigen appears transiently on the surface of megakaryoblasts that have lost HLA-DR antigens and have gained the glycoprotein IIb/IIIa antigen. This study also demonstrated that the proliferating blasts in some patients with TAM were mainly megakaryoblasts and suggested that the target cells in TAM are CFU-GEMM.

Adolescent↗
PubMed1987

Antibody to activated lymphocytes in patients with systemic lupus erythematosus.

IgG antilymphocyte antibodies preferentially reacting with phytohemagglutinin (PHA) activated peripheral blood lymphocytes (PBL) and an adult T cell leukemia cell line were detected in 70.6% sera from patients with systemic lupus erythematosus (SLE), using a fluorescence activated cell sorter (FACS). In the sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, 2 major peaks with an apparent molecular weight 60,000 to 65,000 Da and about 40,000 Da were observed in the membrane glycoprotein fractions of both PHA activated PBL and an adult T cell leukemia cell line. From the result of sequential coprecipitation analysis of SDS-PAGE between SLE serum, antiinterleukin-2 (IL-2) receptor antibody (anti-Tac antibody) and anti-Ia antibody, the reactive antigen on the activated PBL and an adult T cell leukemia cell line proved to be an identical molecule of the IL-2 receptor on these cells. The role of this autoantibody in the modulation of T cell mediated immunity in patients with SLE is discussed.

Antilymphocyte Serum↗
PubMed1987

Expression of lymphocyte-associated antigens on neoplastic angioendotheliomatosis.

Neoplastic angioendotheliomatosis (NAE) is a rare and fatal disorder and has been regarded as a multifocal in situ neoplastic change of endothelial cells. This report describes a case of NAE from whom a biopsy specimen was obtained and studied immunohistologically using several monoclonal antibodies against lymphocyte-associated antigens. The tumor cells occluding luminal space express both T and B cell markers such as Leu-1, Leu-3, Leu-10, Leu-M3, HLA-DR, and HLA-DQ, whereas they do not express Leu-2, Leu-4, lymphocyte-common antigen, and immunoglobulins. Factor VIII as a marker of vascular endothelial cell is false positive in the present case. Since immunoglobulins as a definitive B lymphocyte marker are negative in this case, there is no direct evidence indicating that NAE is a tumor of B lymphocytic lineage as previously reported. These results suggest the two possibilities that NAE is a unique variant of T cell lymphoma or true vascular endothelial tumor sharing the common histogenesis with malignant lymphoma. As it stands the former possibility is more likely than the latter in our case.

Adult↗
PubMed1987

[Plasma fibronectin level in patients with moyamoya disease].

Moyamoya disease is generally considered as a slowly progressive occlusive disease of the circle of Willis. Pathological investigation has revealed that the occlusion develops due to fibrocellular thickening of the intima. In spite of various studies, however, the etiology of this disease and the mechanism of the intimal thickening remain unknown. Fibronectin (FN) is a high molecular weight glycoprotein which is found in an insoluble form in many tissues and in a soluble form in plasma and other body fluids. FNs have many biological activities and play an important role in the formation of connective tissue under physiological and pathological conditions. In the present study we have determined the plasma FN levels in order to investigate the relationship between FN and moyamoya disease. The subjects were 39 patients with moyamoya disease who were in the chronic stage after reconstructive surgery, 39 age- and sex-matched normal healthy controls, and 39 patients with atherosclerotic cerebrovascular disease in the chronic stage. The plasma FN levels were measured by the single radial immunodiffusion method using venous blood samples. The plasma FN level in healthy subjects was 33.9 +/- 6.3 mg/dl (mean +/- standard deviation) which almost agreed with the level, 30-35 mg/dl, reported by some investigators. In the patients with moyamoya disease the level was 42.5 +/- 7.9 mg/dl, showing a significant increase (p less than 0.001) compared with the healthy subjects. Then the subjects were classified into a child group (15 years or younger) and an adult group (16 years or older) and their levels were examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

High-performance liquid chromatographic determination of urinary catecholamines by pre-column solid-phase dansylation on alumina.

Sensitive and selective high-performance liquid chromatographic determination of catecholamines by pre-column solid-phase dansylation is described. After catecholamines are adsorbed on alumina, the amino groups not responsible for adsorption are dansylated by a solid-phase reaction. The excess reagent and fluorescent contaminants are washed out, and the dansylated catecholamines are eluted and separated by reversed-phase high-performance liquid chromatography. The four catecholamine derivatives can be separated within 10 min and no major interfering peak is observed on chromatograms. The response of each catecholamine is linear from 10 to 500 pmol per sample and the detection limit is 0.5 pmol. This method was applied to determination of catecholamines in human urine.

Adult↗
PubMed1986

Excessive fibrinolysis in suspected amyloidosis: demonstration of plasmin-alpha 2-plasmin inhibitor complex and von Willebrand factor fragment in plasma.

We performed a hemostatic evaluation in detail in a patient with suspected amyloidosis who was suffering from several bleeding episodes. He had a shortened euglobulin clot lysis time, decreased alpha 2-plasmin inhibitor (alpha 2-PI), decreased plasminogen, elevated tissue-type plasminogen activator (t-PA), elevated plasmin-alpha 2-PI complex, and decreased ratio of ristocetin cofactor to von Willebrand factor (vWF) antigen. Fibrinogen and fibrin/fibrinogen degradation products levels fluctuated, with abnormal values on several occasions. On crossed immunoelectrophoresis, plasmin-alpha 2-PI complex and vWF fragment were demonstrated in the patient plasma. These abnormal findings and bleeding symptoms improved following the administration of tranexamic acid. Discontinuation of tranexamic acid resulted in deterioration of these parameters. These observations indicate that pathologic fibrinolysis (continuous intravascular plasmin generation) characterized by the consumption of alpha 2-PI and plasminogen, formation of plasmin-alpha 2-PI complex, and fragmentation of vWF contributed to the bleeding in this patient. It is important to recognize excessive fibrinolysis as the underlying cause of bleeding in these patients, since specific treatment with antifibrinolytic agents is effective in controlling the bleeding.

Amyloidosis↗
PubMed1986

Cell cycle-dependent modulation of biosynthesis and stimulus-evoked release of catecholamines in PC12 pheochromocytoma cells.

Catecholamine biosynthesis and its stimulus-evoked release in PC12 pheochromocytoma cells were studied as a function of cell cycle by means of HPLC with electrochemical detection. We found that 3,4-dihydroxyphenylethylamine (dopamine) levels in PC12 cells remained constant throughout the period of cell cycle. In contrast, the noradrenaline content was dependent on the cell cycle: it increased during the S + G2 phase followed by a decrease in the M phase. These results were confirmed further by measuring the activities catalyzing the catecholamine biosynthesis. Thus, activities of tyrosine 3-monooxygenase and 3,4-dihydroxyphenylalanine decarboxylase were independent of the cell cycle, whereas both soluble and membrane-bound dopamine beta-monooxygenase activities were modulated during the cell cycle. On the other hand, release of the catecholamines stimulated with 50 mM KCl increased in the G1 phase, reached a maximum in the late G1, and then gradually decreased in later periods. We also found that carbamylcholine-induced release of the catecholamines occurred maximally in the early S + G2 phase followed by a decrease during the M phase. Cell cycle dependence of the catecholamine release was in good agreement with that of 45Ca2+ uptake. Thus, this study provides evidence that the catecholamine biosynthesis and its release in PC12 cells are modulated during the period of cell cycle.

Animals↗
PubMed1986

Zinc transport during hemodialysis.

Zinc transfer during hemodialysis and plasma zinc concentrations in hemodialysis patients were examined. Fifteen volunteer outpatients undergoing hemodialysis showed significant increases in plasma zinc from 74.0 +/- 7.8 to 88.1 +/- 9.7 micrograms/dl after a 5-h dialysis. The increase was mainly the result of hemoconcentration as evidenced by a significant increase in the hematocrit and total serum protein during dialysis, but was also due to diffusion. To study the changes resulting from diffusion, zinc was measured in the arterial blood and in the dialysate at the inflow and outflow sites of the dialyzer. There was a significant (p less than 0.01) increase in the plasma zinc of the arterial blood from 74.7 +/- 8.1 to 80.2 +/- 6.5 micrograms/dl, but a nonsignificant decrease in the dialysate zinc from 10.6 +/- 2.5 to 9.5 +/- 5.9 micrograms/dl. Zinc diffused across the dialyzer from the dialysate to the blood in 12 cases and into the dialysate in three others.

Adult↗
PubMed1986

Inhibition of erythropoiesis by human parvovirus-containing serum from a patient with hereditary spherocytosis in aplastic crisis.

Aplastic phase serum from a patient with aplastic crisis of hereditary spherocytosis, which was demonstrated to contain human parvovirus, inhibited in vitro erythroid colony formation almost completely. Human parvovirus was resistant to heating for 30 min at 56 degrees C. The suppressive effect of the serum was completely abrogated by adding convalescent phase serum from another patient with aplastic crisis of hereditary spherocytosis. Some normal sera had similar neutralizing ability. The results suggested that aplastic crisis of a patient with hereditary spherocytosis is caused by human parvovirus and that the neutralizing test could offer a tool for predicting the future occurrence of aplastic crisis in the patients with chronic hemolytic anemia.

Adolescent↗