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Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 739 records · Page 41Linked to original sources
PubMed1987

Changes in concentration of human atrial natriuretic peptide in normal pregnancy and toxaemia.

Changes in concentration of human atrial natriuretic peptide (hANP) in normal and toxaemic pregnancy were examined. The maternal plasma concentration of hANP increased gradually during normal pregnancy to a maximum of 20.0 +/- 2.4 pmol/l (mean +/- S.E.M.) after week 36 of pregnancy. From week 20, the plasma concentrations of hANP were significantly higher than those in non-pregnant women (9.3 +/- 2.0 pmol/l). In toxaemia with hypertension, maternal plasma hANP levels were increased after week 26 of pregnancy (37.7 +/- 6.0 pmol/l) compared with those in normal gravida at the same time (17.1 +/- 1.6 pmol/l). Maternal plasma hANP levels in toxaemia only with oedema were not different from those in normal gravida.

Adult↗
PubMed1987

A pharmacological and histological examination of the microcirculation of the rat subcutaneous air-pouch: microcirculation of the rat air-pouch.

The effects of histamine, 5-hydroxytryptamine (5-HT) and prostaglandin E2 (PGE2) on plasma protein extravasation in the rat subcutaneous air-pouch have been studied. Both histamine and 5-HT produced increases in plasma protein extravasation which were inhibited by specific receptor antagonists. Plasma protein extravasation induced by PGE2 was partially inhibited by either a 5-HT receptor antagonist (methysergide) or by a combination of H1 and H2 receptor antagonists (mepyramine and cimetidine). A combination of all three antagonists further reduced plasma protein extravasation. These results suggest that PGE2 increases vascular permeability indirectly via the degranulation of mast cells. This supposition was confirmed by histological evidence of extensive mast cell degranulation following the injection of PGE2 but not following histamine, 5-HT or saline injection. Using a technique of vascular labelling, following the intravenous injection of Monastral blue dye, plasma extravasation induced by histamine, 5-HT or PGE2 was observed to be restricted to post-capillary venules and was not observed in arterioles or capillaries. Electron microscopic examination of the tissue revealed the presence of monastral blue particles trapped between endothelial cells. These findings suggest that the microcirculation of the rat subcutaneous air-pouch behaves in an analogous manner to that of other tissues.

Air↗
PubMed1987

An alternative approach to malaria vaccine with a permanent attenuated mutant from a high virulence Plasmodium berghei strain.

An alternative approach to malaria vaccine with the use of Plasmodium berghei NK65XAT (XAT) is reviewed. XAT is a permanent low virulence strain derived from high virulence P. berghei NK65 (NK65) by irradiation. Although one organism of parent NK65 could kill one mouse, as many as 10(7) XAT parasites caused modest self limiting parasitaemia in immuno-competent mice. In the mice recovered from XAT infection, long lasting immunity to challenge not only by parent NK65, but also by ANKA so far as different species of rodent Plasmodia was seen. The XAT parasites invaded selectively into immature erythrocytes. Because of this feature, the attenuated parasite might induce potent and long-lasting immunity presumably with the background of MHC antigen expression on infected cells. Immunopathologic reactions in mice infected with XAT were modest comparing to those seen in mice with parent NK65 infection. Attenuation was also tested using P. yoelii nigeriensis with which cyclical transmission with A. stephensi was established. Although similar attenuation occurred by X-ray irradiation, produced parasites eventually reverted to virulence after several animal passages. Irradiation was also attempted to induce attenuated P. falciparum mutant and a parasite of a slow multiplication feature was obtained in an experiment. We would propose an alternative approach in the study of malaria vaccine using attenuated live organisms which confers potent and long lasting immunity to the host.

Animals↗
PubMed1987

[Significance of the serum rheumatoid factor-like substance in the induction of arthritis in the rabbit immunized with Escherichia coli].

Rabbits immunized with heat-killed Escherichia coli 0:14 for 8-10 months developed lymphocyte infiltration in the synovium at a significantly (p less than 0.05) higher rate (61.1%, 22 of 36 knees) than animals immunized for 4 months (31.3%, 10 of 32). Serum rheumatoid factor-like substance (RFLS) was positive (RAHA-titer more than 80) as early as 3 weeks after the initial treatment. After 15 weeks of immunization 90.9% (20 of 22 rabbits) of the animals were RFLS positive. Lymphocyte infiltration in the synovium of knees was observed more frequently (81.8%, 9 of 11 rabbits) (p less than 0.05) in the group with positive RFLS earlier than 8 weeks following immunization than in that with RFLS only after this period (18.2%, 2 of 11). These observations suggest that the long viability of serum RFLS and certain factors inducing early RFLS synthesis might be important in producing arthritis in rabbit immunized with E. coli.

Animals↗
PubMed1987

Significance of alcohol dehydrogenase (ADH) as a marker of hepatic centrilobular injury: a biochemical and immunohistochemical study.

Since we demonstrated previously that alcohol dehydrogenase (ADH) is distributed predominantly in zone 3 of the hepatic acinus, we have investigated the usefulness of determinations of serum ADH activity in the assessment of hepatic injuries. The measurement of serum ADH activity appears to be useful for the detection of acute and early centrilobular hepatic damage, as deduced from the results obtained from experimental hepatic injuries produced by bromobenzene, hypoxia and acute administration of ethanol. Whereas serum ADH activity increased slightly after the generation of an acute ethanol load in rats which were given ethanol chronically, the hepatic content of ADH tended to decrease. Moreover, a rather selective reduction of hepatic ADH activity was found in zone 3 of the hepatic acinus. Thus, it is conceivable that chronic alcoholic injury to the liver may result in persistent release of ADH from hepatocytes resulting in a relatively low elevation of the level of the enzyme in the blood, rather than a sudden release of the enzyme leading to a sharp increase in the serum enzyme activity.

Alanine Transaminase↗
PubMed1987

[Granulopoietic effects of lentinan, an antitumor polysaccharide in BALB/c nude mice].

The effect of lentinan on granulopoiesis in BALB/c nude mice (Nu/Nu) was compared with that in their heterozygotes (Nu/+). Lentinan-injected Nu/+ showed enhanced serum colony-stimulating activity (CSA), and increased diphasically granulocyte-macrophage colony forming cells (GM-CFC) in bone marrow and spleen (i.e., first peak on day 1-2 and second peak on day 6). On the other hand, in Nu/Nu, lentinan did not enhance serum CSA, although the control level was higher than the enhanced level in Nu/+. Monophasic increase in GM-CFC was observed in Nu/Nu, but the second peak seen in Nu/+ was not observed. Reconstitution of Nu/+ splenocytes to Nu/Nu increased GM-CFC on day 6, and the increase was augmented by lentinan administration. These results suggest that mature T-cells participate in regulation of granulopoiesis in vivo and that lentinan augments granulopoiesis at least in part via mature T-cell populations.

Animals↗
PubMed1987

[Granulopoietic effects of lentinan in mice: effects on GM-CFC and 5-FU-induced leukopenia].

C57BL mice were injected intravenously with an antitumor immunopotentiating polysaccharide, lentinan, to assess its effect on granulopoiesis in normal mice as well as its ability to enhance the recovery from leukopenia induced by 5-fluorouracil (5-FU). Lentinan increased neutrophils and monocytes in peripheral blood as well as granulocyte-macrophage progenitor cells (GM-CFC) in spleen and bone marrow. Administration of 5-FU induced a significant decrease in GM-CFC from day 1 to day 6, and thereafter the number of GM-CFC rebounded. The administration of 5-FU also suppressed white blood cells such as neutrophils, monocytes and lymphocytes. Injection of lentinan one day after 5-FU resulted in prompt restoration of the leukopenia through the recovery of neutrophils, monocytes and lymphocytes as well as prompt and marked rebound of GM-CFC. These results suggest that lentinan may contribute to the recovery from some of the hematopoietic depression in clinical chemoimmunotherapy.

Animals↗
PubMed1986

Determination of polypeptide chain molecular weights of human and bovine band 3 protein from erythrocyte membranes by low-angle laser light scattering combined with high-performance gel chromatography in the presence of sodium dodecyl sulfate.

Polypeptide chain molecular weights of human and bovine band 3 proteins which are glycoproteins of the erythrocyte membrane were determined as 101,000 +/- 2000 for the former and 107,000 +/- 2000 for the latter by using the low-angle laser light scattering technique combined with a high-performance gel chromatography column, an ultraviolet spectrophotometer and a differential refractometer in the presence of sodium dodecyl sulfate. The advantage of this method is that, unlike the sedimentation equilibrium technique, neither information on the binding to proteins of all ligands present nor the partial specific volume is required to evaluate the polypeptide chain molecular weight of proteins in a multicomponent system.

Animals↗