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Biomedical subjects

M Tagawa

Publications and source records attributed to M Tagawa.

At least 199 records · Page 11Linked to original sources
PubMed1990

A cytotoxic antibody produced by allo-skin transplantation in cats.

A high titer of cytotoxic antibody against donor lymphocytes, tentatively designated as anti-F1, was found in one cat who received 3 times of skin allograft from the same donor. The anti-F1 antibody titer was 1:16, and the antibody activity was mostly detected in the IgG fraction. A cross-absorption test using erythrocytes from F1-positive animals revealed that the F1(+) antigen recognized by anti-F1 antibody was expressed on erythrocytes as well as lymphocytes. The frequencies of F1(+) and F1(-) types in 81 healthy cats, involving all the cats used for allo-immunization in the present study, were 30.9 and 69.1%, respectively. Moreover, F1 antigen was considered to be a hereditary antigen from family studies.

Animals↗
PubMed1990

Decrease in mitogen-induced lymphocyte proliferative responses in cats infected with feline immunodeficiency virus.

The blastformation tests using concanavalin A and pokeweed mitogen were carried out on peripheral blood lymphocytes obtained from cats infected with feline immunodeficiency virus (FIV). The infected cats included those showing multiple chronic disease, those with a single mild sign, and one with no clinical sign. The infected cats showed significantly lower mitogenic responses of peripheral lymphocytes to both mitogens and lower lymphocyte counts as compared to uninfected healthy cats. These immunologic alterations in the infected cats may be closely related to the development of immunodeficiency-like disorders associated with FIV.

Animals↗
PubMed1990

[Long-term treatment for non-A, non-B chronic hepatitis--effects on hepatitis C virus (HCV)].

We have treated 16 patients with chronic non-A, non-B hepatitis with short term (7-13 weeks) and long term (1 year) interferon. Sustained effect (normalization) of treatment was noted in all by long term treatment, where 7 of 8 with short term treatment showed flare-ups of transaminase after the therapy. In addition, negative turn of anti-HCV antibody was noted in 2 of 5 patients with long term treatment, whereas such change was noted in none of 6 anti-HCV antibody positive patients treated with short term treatment. These data suggest that long term interferon therapy may change natural course of chronic non-A, non-B hepatitis caused by HCV.

Adult↗
PubMed1990

[Changes in plasma granulocyte elastase, myeloperoxidase and fibronectin during and after open heart surgery].

Arterial and pulmonary arterial levels of plasma granulocyte elastase, myeloperoxidase and fibronectin were measured during and after cardiac surgery by using a bubble oxygenator. Granulocyte elastase-proteinase inhibitor and myeloperoxidase increased significantly from the end of cardiopulmonary bypass to the first postoperative day. The levels of granulocyte elastase-proteinase inhibitor and myeloperoxidase correlated with the perfusion time with cardiopulmonary bypass, but did not correlate with respiratory index except correlation of the level of arterial myeloperoxidase with respiratory index on the first postoperative day. We speculate that microvascular leukostasis occurs after cardiopulmonary bypass on account of the differences of the level of myeloperoxidase between arterial and pulmonary arterial blood. Plasma fibronectin decreased slightly during operation and on the first postoperative day.

Adult↗
PubMed1989

Localization of chemotactic activity and 64 kD protein phosphorylation for human polymorphonuclear leukocytes in N-terminus of the chemotactic protein LUCT/IL-8.

A synthetic peptide, AVLPRSAKEL (LU10), the N-terminal amino acid sequence of chemotactic protein (LUCT/IL-8), showed chemotactic activity to polymorphonuclear leukocytes (PMN) with an ED50 of 5 nM for comparable to that of LUCT. Native LUCT and LU10 specifically induced the phosphorylation of 64 kD protein of PMN, and serine residue in the 64 kD protein was major phosphorylated amino acid. Furthermore, native LUCT enhanced the release of myeloperoxidase and beta-glucuronidase from PMN in the presence of cytochalasin B and FMLP, but LU10 did not. These results strongly suggest that the active site for both chemotactic stimulation and 64 kD protein phosphorylation is localized on the sequence of N-terminal 10 amino acids of LUCT.

Amino Acid Sequence↗
PubMed1989

Preparation and characterization of monoclonal antibodies against human myeloperoxidase.

We established 11 hybridomas producing monoclonal antibodies (MoAbs), designated AM, against human myeloperoxidase (MPO), by immunizing mice with the three forms of MPO (I, II, and III) purified from healthy human polymorphonuclear leukocytes (PMN) and characterized the specificity of the AM MoAbs. Ten of the AM MoAbs reacted similarly to each of the three forms using an enzyme-linked immunosorbent assay. When a cetyltrimethylammonium bromide (CETAB) extract of human PMN was electrophoresed in a CETAB polyacrylamide gel and transferred to a nitrocellulose filter, IgG1 class AM MoAbs immunostained only the MPO band of the proteins of the extract. In addition, the AM MoAbs reacted to two radioactive bands of 94 and 92 kDa in a HL-60 cell lysate labeled with [35S]methionine for 1 h. After a chase period of 24 h, these bands were replaced by four radioactive bands of 64.5, 43, 16.7, and 13.4 kDa, demonstrating that the MoAbs recognize not only mature MPO but also the MPO precursors of 94 and 92 kDa. The data also indicated that the two major bands of 64.5 and 13.4 kDa corresponded to heavy and light chains of mature MPO, respectively, and the additive intermediate bands of 43 and 16.7 kDa were MPO-related proteins. Moreover, AM MoAbs reacted to a similar extent to the deglycosylated form of MPO III with endo-beta-N-acetylglucosaminidase H (Endo-H). Thus, IgG1 class AM MoAbs recognized MPO with high specificity and reacted to the structure which is commonly conserved in the three mature forms of MPO (I, II, and III), MPO precursors, and deglycosylated MPO with Endo-H. AM MoAbs also specifically reacted to PMN and/or monocytes but did not react to lymphocytes when the cell staining method was used.

Animals↗
PubMed1989

Purification and partial primary sequence of a chemotactic protein for polymorphonuclear leukocytes derived from human lung giant cell carcinoma LU65C cells.

A chemotactic protein for polymorphonuclear leukocytes (lung carcinoma-derived chemotaxin [LUCT]) was purified from culture fluid of the human lung giant cell carcinoma LU65C cells to electrophoretically homogeneous form through five sequential purification steps: DEAE-Sepharose, CM-Sepharose, HPLC on carboxyl-methylated-polyvinylalcohol resin, hydrophobic, and reversed-phase. The molecular mass was determined as approximately 10 kD by SDS-PAGE and isoelectric point was 10.7. The chemotactic activity (ED50 0.75 x 10(-9) M) was sevenfold more potent than that of FMLP (5 X 10(-9) M) and comparable with that of C5a (10(-9) M). NH2-terminal amino acid sequence and amino acid composition of LUCT strongly suggest that it may be closely related to the putative protein encoded by the cDNA clone (3-10C) and almost identical with a part of sequence of the chemotactic factor derived from stimulated human leukocytes in the 6th to 32nd, but not the NH2-terminal 5 amino acids. These results indicate that the carcinoma cells produce LUCT without any added stimulant and suggest that the previously isolated chemotactic monokines may correspond to des(1-5) of LUCT in the NH2-terminal region.

Amino Acid Sequence↗
PubMed1989

In vivo and in vitro phosphorylation of murine lymphocyte differentiation antigen CD5.

Ly-1, the murine lymphocyte differentiation antigen CD5, is phosphorylated constitutively in vivo. This phosphorylation is enhanced by phorbol 12-myristate 13-acetate (PMA) treatment, but not by concanavalin A, Ca2+ ionophore or dibutyryl cAMP. Prolonged PMA treatment abolished PMA-induced Ly-1 phosphorylation but not constitutive phosphorylation, suggesting that protein kinase C (PKC) is responsible for this enhanced phosphorylation, but not the basal phosphorylation of Ly-1. Ly-1 is phosphorylated by PKC added to membranes, further supporting a role for protein kinase C in the in vivo phosphorylation of Ly-1.

Amino Acids↗
PubMed1989

Changes in tissue and blood concentrations of thyroid hormones in developing chum salmon.

The changes in tissue and blood concentrations of thyroxine (T4) and triiodothyronine (T3) were examined during development of the chum salmon (Oncorhynchus keta). Extraction methods previously established for tissue T4 were also validated for tissue T3, by parallel displacement curves to T3 standard in the radioimmunoassay and by the same elution patterns of immunoreactivity in a HPLC system. The T3 concentration of the eggs just after fertilization (4-9 ng/g) was lower than the T4 concentration (5-15 ng/g). Both T4 and T3 concentrations in the whole body decreased steadily during yolk absorption, primarily due to the decline of the hormone content in the yolk. Both T4 and T3 were detected in blood plasma at later stages of yolk absorption, and the plasma levels increased toward the end of yolk absorption. At the end of yolk absorption, when the larvae emerge from the gravel bed, a transient increase in whole body concentrations of T4 and T3 was observed. Plasma levels of T4 were always greater than the T3 levels. Thyroid follicles began to develop during the early stages of yolk absorption. These findings suggest important roles of maternal thyroid hormones for developing salmon embryos during yolk absorption.

Animals↗
PubMed1989

Some pharmacological properties of a new antitumor drug, CPT-11, in isolated muscle preparations.

1. Pharmacological properties of a new antitumor drug, CPT-11, were studied in some muscle preparations. 2. CPT-11 induced contraction of guinea-pig ileal and tracheal preparations, which was blocked by atropine (10(-6) M). 3. CPT-11 potentiated the contractile responses of guinea-pig ileum to acetylcholine, nicotine, serotonin and BaCl2. 4. The chronic and inotropic effects induced by isoprenaline were depressed by CPT-11. 5. These results suggest that CPT-11 has an acetylcholine action.

Animals↗
PubMed1989

Effects of bovine TSH on the tissue thyroxine level and metamorphosis in prometamorphic flounder larvae.

Bovine thyroid-stimulating hormone (TSH) was microinjected (0.2 microliter/fish) into prometamorphic flounder larvae and the effects on metamorphosis as well as the tissue thyroxine (T4) and triiodothyronine (T3) levels were studied. After a single injection of TSH (5 mIU/g), the tissue T4 concentration increased markedly after 5 hr, reached a peak after 10 hr, and decreased subsequently. T4 concentration after 24 hr was still higher than in saline-injected fish but returned to the control level 48 hr after the injection. On the other hand, tissue T3 concentration was kept lower than the detectable level (0.2 ng/g) throughout the experimental period of 72 hr after a single injection of TSH (5 mIU/g). TSH treatment also accelerated the process of metamorphic climax, such as shortening of the second fin ray and eye migration. These results suggest that an increased secretion of TSH from the pituitary stimulates the thyroid, resulting in a surge of the tissue T4 concentration which induces the climax of the flounder larvae.

Aging↗
PubMed1989

Genomic DNA with transformation-related activity and melanoma antigen expression.

We have analyzed the mouse melanoma antigen with monoclonal antibodies established by syngeneic immunization. To further understand the structure of this antigen at a molecular level, we have cloned the genomic DNA controlling the expression of melanoma antigen by cosmid library transfection and a monoclonal antibody. In the process of analyzing this DNA fragment we found that it contained a gene related with transformation, which was proved by tumor formation in nude mice inoculated with NIH/3T3 transfectants of this DNA fragment. We discuss the structure of the gene product based on the deduced amino acid sequence of cDNA, which maps the genome bearing transformation-related activity.

Animals↗
PubMed1989

Properties of mouse melanoma antigen and its secretion mechanism from the cell surface.

We analyzed the biochemical properties and biological significance of the melanoma antigen secreted in the culture supernatants of B16 melanoma cells. The 80 kilodalton (kd) molecule bearing the epitopes of mouse melanoma antigen was found to associate noncovalently with an 18 kd moiety in the culture supernatants as well as on the cell surface. Tunicamycin treatment of B16 cells did not affect the expression of the 69 kd nonglycosylated form of the 80 kd molecule but did abolish the association between the two molecules on the cell surface. We could not detect this antigen as a soluble form when the N-linked glycosylation was inhibited. Therefore, the glycosylation of the 80 kd molecule is essential for the formation of the 80 kd/18 kd complex and also for the secretion. Moreover, the affinity-purified melanoma antigen from the supernatants could induce anti-melanoma suppressor cells which block the generation of cytotoxic T lymphocytes against melanoma cells. Thus, the 80 kd glycoprotein as a soluble melanoma antigen performed a pivotal function in the escape mechanisms of melanoma cells from the host immune surveillance system.

Animals↗
PubMed1989

Biochemical characterization of an antigen-specific suppressor T cell factor.

We describe here the biochemical properties of suppressor T cell factor (TsF2) released from an inducible anti-idiotypic T cell hybridoma (C57BL/6 T cell x BW5147) which mediates antigen (keyhole limpet hemocyanin) specific and genetically (H-2b) restricted suppression of IgG plaque-forming cell responses. We examined the suppressive activity by in vitro functional assay in fractions of chromatography and in the materials eluted from gels of sodium dodecyl sulfate polyacrylamide and isoelectric focusing and determined the molecular weight(s) (22-37 kD) and the isoelectric point(s) (pH 6.0-6.1) of this secreted factor. Messenger RNA products of the hybridoma translated in the rabbit reticulocyte lysate system were similarly examined, and the functionally active molecule was seen to migrate to almost the similar molecular weight(s) (23-40 kD), and isoelectric point(s) (pH 5.5-6.2) range as those of secreted TsF. Moreover, the TsF activity was recovered from gel slice corresponding to the similar molecular weight range analyzed in sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing and nonreducing conditions. Thus, we speculate that this molecule is composed of a single chain, biologically active. Comparison of autoradiograms on in vitro translation products between activated and resting hybridomas by two-dimensional gel electrophoresis showed that the molecular weights and isoelectric points of two spots (28 kD, 5.7; 25 kD, 5.5) newly appearing or markedly enhanced after activation in the area with suppressor activity were concordant with the data on secreted TsF, suggesting that one of these two spots represents the functional molecule which causes antigen-specific and genetically restricted suppression of IgG responses.

Animals↗
PubMed1989

Changes in plasma cortisol concentration by ages in dogs under ketamine and thiopental anesthesia.

In order to examine the change in adrenocortical responses with age in dogs, 36 healthy beagle dogs were divided by age into 6 groups and were treated with ketamine or thiopental. The plasma cortisol concentrations were determined before and after the treatment. The concentrations prior to the induction of anesthesia were 2.23 +/- 0.44 micrograms/dl (mean +/- SD) in pups (2 to 3 months old), 4.35 +/- 2.04 micrograms/dl in adults (2 years old), and 3.40 +/- 1.25 micrograms/dl in aged dogs (8 to 10 years old). This result indicated the following order of plasma cortisol levels in dogs: pups less than aged dogs less than adults. The plasma cortisol concentrations after ketamine administration tended to increase. This suggested that the adrenocortical function in the dog was stimulated by ketamine. In the ketamine treated dogs, significant differences were demonstrated among the age groups. Namely, a significantly lower response was noted in pups compared to adults or aged dogs (p less than 0.001). On the other hand, the plasma cortisol levels after the thiopental treatment showed a temporary slight increase in aged dogs but tended to decrease in pups and adults. Thiopental was found to have a suppressive effect on the adrenocortical function in dogs in contrast to ketamine.

Adrenal Cortex↗