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Biomedical subjects

H Tsuda

Publications and source records attributed to H Tsuda.

At least 559 records · Page 31Linked to original sources
PubMed1985

Variation in the clinical courses of adult T-cell leukemia.

Twenty-nine cases of adult T-cell leukemia were classified into four types according to the clinical features and course: smoldering, chronic, crisis, and acute. Only 2 of 14 patients with the acute type responded to therapy. The four types showed apparent differences in clinical features, complications, and prognosis, suggesting the need for different therapeutic regimens. For smoldering and chronic cases, no chemotherapy is recommended. However, in crisis and acute cases, aggressive chemotherapy is necessary, although the acute type cases showed extremely poor prognosis despite the most aggressive chemotherapy.

Acute Disease↗
PubMed1985

Abnormal expression pattern of Tac and T9 antigens on in vitro activation of leukemic T cells.

Mitogen-induced T-lymphocyte proliferation is dependent on the presence of both interleukin 2 (IL-2) and transferrin, even though resting lymphocytes do not have receptors for either. Recently, it has been reported that IL-2 stimulates T-lymphocyte proliferation via IL-2 receptor by induction of transferrin receptor on these cells. Using leukemic T cells as a model of the monoclonal mature T cell, we examined those sequential steps of T-cell activation. Our studies revealed that transferrin receptors do not always appear after IL-2 receptor expression, IL-2 up-regulates the expression of IL-2 receptor but not of transferrin receptor, and IL-2 can initiate DNA synthesis without altering transferrin receptor expression. Thus, the sequential activation steps reported for normal T cells were not observed in the present study on leukemic T cells. These data suggest that there are other pathways to DNA synthesis in leukemic T cells and even in normal T cells.

Antigens, Neoplasm↗
PubMed1985

Inhibitory potential of acetaminophen and o-, m-, p- aminophenols for development of gamma-glutamyltranspeptidase-positive liver cell foci in rats pretreated with diethylnitrosamine.

The inhibitory potential of treatment with acetaminophen (AAP) and 3 different isometric forms of monoaminophenols (o-, m-, p-AP) for the development of gamma-glutamyltranspeptidase-positive (gamma-GT+) liver cell foci was examined in an in vivo short-term assay system. Rats were initially given a single intraperitoneal injection of diethylnitrosamine (DEN) and fed test compounds from week 2 until they were killed at week 6, all rats being subjected to two-thirds partial hepatectomy at week 3. All 4 compounds exerted obvious inhibition of the development of gamma-GT foci with both number and area (mm2) being reduced. AAP proved the most potent agent whereas dose-related inhibitory potential was observed within the 2 doses of p-AP treated.

Acetaminophen↗
PubMed1985

Dose-dependent effects of butylated hydroxyanisole, butylated hydroxytoluene and ethoxyquin in induction of foci of rat liver cells containing the placental form of glutathione S-transferase.

The dose-dependence effects of 3 antioxidants, butylated hydroxyanisole (BHA: 2.0%, 1.0% and 0.5%), butylated hydroxytoluene (BHT: 1.0%, 0.5% and 0.25%) and ethoxyquin (EQ: 0.5%, 0.25% and 0.125%) combined with partial hepatectomy on the development of preneoplastic lesions in the liver of diethylnitrosamine (DEN, 200 mg/kg body wt)-treated rats were investigated. Feeding of the antioxidants commenced 2 weeks after the single dose of DEN used to initiate the lesions. gamma-Glutamyl transpeptidase (gamma-GT) and the placental form of glutathione S-transferase (GST-P) were used for quantitation of altered focal populations. Results with both markers demonstrated a dose-dependent decrease of foci in BHA-treated rats relative to those in control rats. Morphometric analysis of gamma-GT-positive lesions also revealed decrease in both the number and area of foci in BHT- and EQ-treated groups. The discrepancy between results of quantitation of gamma-GT- and GST-P-positive foci was attributable to the induction of a background, periportal zone staining for gamma-GT, which made differentiation of smaller foci difficult. Comparison of results with the 2 markers suggested that GST-P is the more accurate marker for quantitative studies on enzyme altered foci in rat liver.

Animals↗
PubMed1985

The role of Ca2+ and Ca2+-activated phospholipid-dependent protein kinase in degranulation of human neutrophils.

The degranulation reactions of human neutrophils induced by 1-oleoyl-2-acetylglycerol (OAG), phorbol 12-myristate 13-acetate (PMA), and calcium ionophore A23187 or their combinations, were studied. OAG in the absence of the Ca2+-ionophore A23187 stimulated the releases of both lysozyme and lactoferrin, constituents of the specific granules, but did not stimulate the release of beta-glucuronidase, an enzyme of the azurophil granules. Electron microscopy revealed a selective decrease in the numbers of the specific granules in this case. The combined effects of A23187 at a concentration higher than 0.1 microM and OAG were essentially additive. W-7, known to be an inhibitor of both Ca2+-activated phospholipid-dependent protein kinase (C-kinase) and calmodulin, inhibited the degranulation induced by OAG or PMA, while it inhibited the reaction induced by A23187 less markedly. The release of lysozyme reached a plateau at about 0.1 microM A23187 and increased again at higher concentrations of A23187. The observations suggest that degranulation can be induced by the activation of the C-kinase, and the degranulation by A23187 at low concentrations may be due to the activation of the C-kinase; the effects of A23187 at high concentrations, however, could not be explained only in terms of the activation of the C-kinase.

Bucladesine↗
PubMed1985

Comparative effects of carcinogens on the induction of placental glutathione S-transferase-positive liver nodules in a short-term assay and of hepatocellular carcinomas in a long-term assay.

The dose-dependent effects of three hepatocarcinogens were investigated by measuring the number and area of glutathione S-transferase placental form (GST-P)-positive foci and nodules appearing in the liver under short-term conditions (Experiment I) and evaluating the incidence of hepatocellular carcinoma after long-term chronic administration (Experiment II). For these purposes, three different doses of 2-acetylaminofluorene (2-AAF), 3'-methyl-4-dimethy-laminoazobenzene (3'-Me-DAB), and DL-ethionine (ethionine) were given to male F344 rats for 6 weeks after a single injection of diethylnitrosamine (DENA) in Experiment I or for 104 weeks without initiation by DENA in Experiment II. In Experiment I, the induction of GST-P-positive foci and nodules by 2-AAF and 3'-Me-DAB was clearly dose-dependent. In contrast, ethionine showed enhancing effects inducing GST-P-positive foci and nodules only in groups given the highest dose level. Similarly, in Experiment II, induction of hepatocellular carcinomas by 2-AAF and 3'-Me-DAB was clearly dose-dependent, whereas liver neoplasms were only induced by the highest dose level of ethionine. These results indicate that degree of induction of GST-P positive foci and nodules in a short-term in vivo test for liver carcinogens corresponds with the incidences of hepatocellular carcinomas revealed in a long-term in vivo assay.

Animals↗
PubMed1985

Carcinogenicity and modification of the carcinogenic response by BHA, BHT, and other antioxidants.

Carcinogenicity tests showed that addition of the antioxidant BHA to the diet of F344 rats induced high incidences of papilloma and squamous cell carcinoma of the forestomach of both sexes. Male hamsters given BHA for 24 weeks also developed papilloma showing downward growth into the submucosa of the forestomach. These results indicate that BHA should be classified in the category of "sufficient evidence of carcinogenicity" as judged by IARC criteria. The 3-tert isomer of BHA seemed to be responsible for the carcinogenicity of crude BHA in the forestomach of rats. BHT was not found to be carcinogenic in rats or mice. In two-stage carcinogenesis in rats after appropriate initiation, BHA enhanced carcinogenesis in the forestomach and urinary bladder of rats, but inhibited carcinogenesis in the liver. BHT enhanced the induction of urinary bladder tumors and inhibited that of liver tumors, but had no effect on carcinogenesis in the forestomach. BHT could be a promoter of thyroid carcinogenesis. Sodium L-ascorbate enhanced forestomach and urinary bladder carcinogenesis. Ethoxyquin enhanced kidney and urinary bladder carcinogenesis, but inhibited liver carcinogenesis. Thus, these antioxidants modify two-stage chemical carcinogenesis in the forestomach, liver, kidney, urinary bladder, and thyroid, but show organ-specific differences in effects.

Animals↗
PubMed1985

Clinical diversity in adult T-cell leukemia-lymphoma.

Adult T-cell leukemia-lymphoma (ATL) is a unique T-cell cancer first described in Japan. We estimate that more than 200 patients a year have been detected in Kyushu. The surface phenotype of ATL cells characterized by monoclonal antibodies is T3+, T4+, T8-, T11+, and Tac+. In all cases the serum is positive for anti-human T-cell leukemia (lymphotropic) virus (HTLV-I) antibodies and the ATL cells contain the proviral DNA of HTLV-I. Variations in the clinical features of atypical cases suggest a division of the spectrum of ATL into five types: acute (prototypic), chronic, smoldering, crisis, and lymphoma. Screening of the sera from healthy adults for presence of the anti-HTLV-I antibodies revealed that 3.6% of healthy individuals in Kumamoto Prefecture, which is located in the middle of Kyushu, were HTLV-I carriers. The percentage of positivity increased with age and was higher in females than in males. It varied from town to town, ranging from 0 to 17.6%. Family studies showed that the routes of natural infection of HTLV-I are from mother to child and also from husband to wife. The third route is blood transfusion. The borderline between the healthy carrier state and smoldering ATL remains unclear. In the endemic areas smoldering ATL is frequently diagnosed in patients with fungus infection of the skin, chronic lymphadenopathy, interstitial pneumonitis, chronic renal failure, and strongyloidiasis. In addition our experiences with a concurrence of lymphoma-type ATL in three sisters and spontaneous remissions in a patient with chronic ATL are cited.

Adult↗
PubMed1985

Comparison of the various forms of glutathione S-transferase with glucose-6-phosphate dehydrogenase and gamma-glutamyltranspeptidase as markers of preneoplastic and neoplastic lesions in rat kidney induced by N-ethyl-N-hydroxyethylnitrosamine.

Alterations in gamma-glutamyl transpeptidase (gamma-GT) and alkaline phosphatase (ALP) activities and binding of specific antibodies to glucose-6-phosphate dehydrogenase (G6PDH), gamma-GT and the A, B, C, D, and P forms of glutathione S-transferase (GST-A, -B, -C, -D, and -P, respectively) in preneoplastic and neoplastic lesions induced by N-ethyl-N-hydroxyethylnitrosamine (EHEN) in the rat kidney were investigated. Morphologically the lesions were of basophilic type and were classified either as altered tubules or adenomas, the latter being further subdivided into microadenomas and adenomas depending on size and the presence of compression. The fact that all lesions demonstrated only weak (or negative) gamma-GT, ALP and GST-B stainings, all of which are normally evident in proximal tubules, and also the occasional finding of cells bearing a periodic acid-Schiff-positive apical brush border within altered tubules strongly positive for GST-A, indicated their histogenesis from the proximal segment of the nephron. Thus a directed shift to a phenotype opposite to that observed in the cells of origin was demonstrated. Comparison of phenotype within the range of EHEN-induced lesions strongly suggested putative preneoplastic character for the altered tubules. Transition to adenomas appeared to be correlated with progressive loss of GST-A and moderate to slight increase of G6PDH.

Adenoma↗
PubMed1985

Chromosomal aberrations in adult T cell leukemia: relationship to the clinical severity.

A chromosome study was performed in 18 patients with adult T cell leukemia (ATL), who were divided into three groups according to their clinical manifestations: nine had acute ATL, six had chronic ATL, and three had smoldering ATL. Mitotic cells were obtained from peripheral blood, lymph node, or bone marrow and were analyzed by the G-banding technique. In acute ATL, the chromosome number ranged from diploid or pseudodiploid to hyperdiploid; in the chronic type, from hypodiploid to hyperdiploid; but in the smoldering type, it was diploid. Eight of nine patients with acute ATL had trisomy 3 and/or trisomy 7, whereas none of those with chronic ATL exhibited these aberrations. Patients with smoldering ATL had a normal karyotype. The present findings indicate that the more aggressive the clinical course of ATL, the more complex the numerical and structural chromosome abnormality.

Adult↗
PubMed1985

HLA antigens associated with systemic lupus erythematosus in Japan.

We studied whether or not HLA-A,B,C and DR antigens were associated with clinical and immunological findings in 116 patients with systemic lupus erythematosus (SLE) in Japan. SLE patients tended to be associated with HLA-DR2, compared with 75 healthy individuals. Among the SLE patients, there was an association between HLA antigens and the presence or absence of certain clinical or immunological features. Different HLA antigens might have a predictive value for SLE and/or the same clinical and immunological abnormalities between Caucasian and Japanese SLE patients.

Antibodies, Antinuclear↗