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Biomedical subjects

K Terao

Publications and source records attributed to K Terao.

At least 109 records · Page 6Linked to original sources
PubMed1990

Orosomucoid typing by isoelectric focusing: genetic variation of orosomucoid in Asian macaques (genus Macaca).

Genetic variation of orosomucoid (ORM) in the genus Macaca was investigated. Plasma samples were subjected to isoelectric focusing in a pH range of 4-6.5, followed by immunoprinting with anti-human ORM antibodies. A total of 25 alleles were identified in 231 Asian macaques belonging to 13 species from 23 populations and 22 members belonging to a family of M. fascicularis. Family data presented evidence for a codominant mode of inheritance with multi-alleles at a single autosomal locus. A population study revealed enormous intra- and interspecies variations. The heterozygosity values varied from 0.855 in M. fascicularis (Malaysia) to 0.000 in M. radiata (India), M. silenus (India) and M. arctoides (Malaysia).

Animals↗
PubMed1990

Experimental acute poisoning in mice induced by emestrin, a new mycotoxin isolated from Emericella species.

The effects of emestrin (EMS), a secondary metabolite of the Emericella species, on male ICR mice were examined. The intraperitoneal LD50 values of EMS were 17.7 and 13.0 mg/kg at 24 and 48 hr, respectively. The target organs of EMS were the heart, liver and thymus. In doses over 30 mg/kg the experimental animals died from cardiac failure shortly after the injections. Several survivors that were given EMS in doses under 20 mg/kg showed severe centrilobular necrosis in the liver at 24 hr. Marked degeneration of mitochondria was seen in electron micrographs of both cardiac muscle cells and hepatocytes. In the degenerated hepatocytes, prominent proliferation of RER, membrane-limited inclusions containing both ribosome-like granules and RER, and fenestrated lamella-like structures were observed. Massive necrosis of lymphocytes was always observed in the cortical layer of the thymus of the survivors within 24 hr, while bilateral adrenalectomized mice showed no discernible pathomorphological changes in the lymphoid tissues. Pretreatment of mice with diethyl maleate increased the incidence and severity of hepatic necrosis, whereas that with either cysteine or CoCl2 reduced the severity of centrilobular necrosis of the liver. Pretreatment with phenobarbital had no significant effect on EMS-induced hepatic lesions.

Animals↗
PubMed1990

A toxic substance produced by Nocardia otitidiscaviarum isolated from cutaneous nocardiosis.

During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD50 value was 1.25 mg/kg and the ED50 value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C43H68O12. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans.

Aged↗
PubMed1990

Histopathological studies on experimental marine toxin poisoning--5. The effects in mice of yessotoxin isolated from Patinopecten yessoensis and of a desulfated derivative.

The histopathological response of male ICR mice to yessotoxin, isolated from the digestive organ of scallops Patinopecten yessoensis, was compared with that of desulfated yessotoxin. The target organ of the former was the heart and those of the latter were the liver and pancreas. Electron microscopically, marked intracytoplasmic edema in cardiac muscle cells was seen within 3 hr after the i.p. injection of over 300 micrograms/kg of yessotoxin. In contrast, desulfated yessotoxin at the same dose caused within 24 hr of i.p. injection severe fatty degeneration and intracellular necrosis in the liver and pancreas but not in the heart. Biochemically, the content of triglycerides in the liver of mice treated with desulfated yessotoxin increased about 60 times, and phospholipids two-fold more than the control levels of those of mice treated with yessotoxin.

Animals↗
PubMed1989

Swelling of the Golgi apparatus and decrease of galactosyltransferase in polyamine-deficient bovine lymphocytes and epithelium of mouse small intestine.

When bovine small lymphocytes stimulated by concanavalin A were treated with inhibitors (alpha-difluoromethylornithine (5 mM) and ethylglyoxal bis(guanylhydrazone) (100 microM)] of polyamine biosynthesis, swelling of the Golgi apparatus was observed. This was accompanied by decreases in the amount of the Golgi apparatus and of the specific activity of galactosyltransferase. Both spermidine and spermine, at physiological concentrations, stimulated galactosyltransferase activity 2-3-fold. When mice were treated with these inhibitors, the following changes were observed in the epithelial cells of small intestine: swelling of the Golgi apparatus; decrease in the amount of the Golgi apparatus; and decrease of galactosyltransferase activity.

Animals↗
PubMed1989

Histopathological studies on experimental marine toxin poisoning--III. Morphological changes in the liver and thymus of male ICR mice induced by goniodomin A, isolated from the dinoflagellate Goniodoma pseudogoniaulax.

The i.p. LD50 values of goniodomin A, a novel polyether macrolide, in male ICR mice were 1.2 and 0.7 mg/kg at 24 and 48 hr, respectively. Histologically, perihepatitis, non-fatty vacuoles in the hepatocytes, central necrosis of the liver and massive necrosis of lymphocytes, in the cortical layer of the thymus, were prominent.

Animals↗
PubMed1989

Histopathological studies on experimental marine toxin poisoning--4. Pathogenesis of experimental maitotoxin poisoning.

Repeated injections of 45 ng/kg of maitotoxin into the peritoneal cavities of male ICR mice resulted in marked atrophy of lymphoid tissues, a reduction of lymphocytes in the circulating blood, reduced immunoglobulin M in serum, and an increase of calcium content in the adrenal glands. A single injection of 200 ng/kg of maitotoxin induced a marked increase in total calcium content of the adrenal glands as well as in plasma cortisol concentration (about seven times control) within 1 hr. In contrast, mice pretreated with CoCl2, a calcium channel inhibitor, and/or adrenalectomized mice, showed no discernible changes in the lymphoid tissues after repeated injections of maitotoxin. It is thus suggested that maitotoxin first stimulates calcium influx in the adrenal glands, which then causes the release of cortisol into the blood. The excess amount of cortisol in serum produces acute involution of the thymus and other lymphoid tissues.

Adrenal Cortex↗
PubMed1989

Different responses of albumin-containing and alpha-fetoprotein-containing cells to estriol in the adult mouse liver.

A single intraperitoneal injection of 10 mg estriol (E3) rapidly induced a transient decrease in the serum albumin (ALB) level in 3 to 5 days in adult mice. At a dose of 5 mg, E3 showed a remarkable threshold effect on the decline of serum ALB. By immunohistochemistry, two types of ALB-positive cells were found in the liver. Type 1 cells were stained intensely and almost homogeneously throughout all or nearly all their entire cytoplasm, and type 2 cells showed only granular or vesicular cytoplasmic deposits. After administration of 10 mg E3, the type 1 cells diminished rapidly and markedly in direct proportion to the fall in serum ALB from the centro- and mediolobular zones, where they had been normally localized either singly or in small groups. Simultaneously, the granular or vesicular deposits that had been normally stained very weakly in the type 2 cells in the centro- and mediolobular zones became intensely stained along with cells in the perilobular zone. Alpha-fetoprotein (AFP)-containing cells in the liver appeared in maximal numbers at 5 to 7 days after E3 administration. These serological and cytological changes after E3 administration are here discussed on the basis of a possible inverse relationship between ALB and AFP gene expression.

Albumins↗
PubMed1989

P blood group and proneness to urinary tract infection in Japanese children.

The globoseries of glycolipids are antigens in the P blood group system as well as epithelial cell receptors for uropathogenic Escherichia coli. The P1 blood group is overrepresented in Swedish girls with recurrent pyelonephritis. In this study, Japanese children with urinary tract infection (UTI) were analyzed for P blood group phenotype. Out of 26 children with recurrent UTI, 50% were of the P1 blood group compared to the 31% of P1 individuals in the Japanese population at large (p less than 0.05). Of children defined as having febrile UTI 62% were P1. The P1 blood group was thus significantly enriched (3.5 times) in the children with febrile UTI. These results support the hypothesis that individuals of blood group P1 run an increased risk for recurrent pyelonephritis.

Adolescent↗
PubMed1988

Oxidative hemolysis of erythrocytes and its inhibition by free radical scavengers.

The oxidative hemolysis of rabbit erythrocytes induced by free radicals and its inhibition by chain-breaking antioxidants have been studied. The free radicals were generated from either a water-soluble or a lipid-soluble azo compound which, upon its thermal decomposition, gave carbon radicals that reacted with oxygen immediately to give peroxyl radicals. The radicals generated in the aqueous phase from a water-soluble azo compound induced hemolysis in air, but little hemolysis was observed in the absence of oxygen. Water-soluble chain-breaking antioxidants, such as ascorbic acid, uric acid, and water-soluble chromanol, suppressed the hemolysis dose dependently. Vitamin E in the erythrocyte membranes was also effective in suppressing the hemolysis. 2,2,5,7,8-Pentamethyl-6-chromanol, a vitamin E analogue without phytyl side chain, incorporated into dimyristoylphosphatidylcholine liposomes, suppressed the above hemolysis, but alpha-tocopherol did not suppress the hemolysis. Soybean phosphatidylcholine liposomes also induced hemolysis, and a lipid-soluble azo initiator incorporated into the soybean phosphatidylcholine liposomes accelerated the hemolysis. The chain-breaking antioxidants incorporated into the liposomes were also effective in suppressing this hemolysis.

Animals↗
PubMed1988

Ricin and alpha-sarcin alter the conformation of 60S ribosomal subunits at neighboring but different sites.

The effects of ricin and alpha-sarcin separately or in combination on the conformation of rat liver ribosomes were investigated by measuring the relative accessibility of individual ribosomal proteins to N-ethylmaleimide after 80S ribosomes were treated with these toxins. By using a double-labelling technique in which ribosomes were incubated with the toxins and then treated with 3H-labelled or 14C-labelled N-ethylmaleimide, it was found that labelling of protein L14 was specifically reduced by treatment with ricin, and that of proteins L3 and L4 by treatment with alpha-sarcin, suggesting that the toxins alter the conformation of ribosomes in the vicinity of these proteins. When ribosomes were treated with both ricin and alpha-sarcin, the extent of labelling of protein L3 was reduced compared to that observed after treatment with alpha-sarcin alone. These results are discussed in relation to previous observations showing that these three proteins are neighbours in the 60S ribosomal subunit and probably play important roles in protein biosynthesis, and in the actions of ricin and alpha-sarcin on 28S rRNA.

Animals↗
PubMed1988

The effect of dietary lipid hydroperoxide on lymphoid tissues in mice.

Effects of dietary lipid hydroperoxides on lymphoid tissue were studied in mice. When graded amounts (190, 270 and 310 mg) of methyl linoleate hydroperoxide (MLHPO) were orally administered to male C57BL/6 mice (6 weeks old), necrosis was observed in lymphocytes located among the reticular network in the thymus, and thymus weight was significantly decreased 24 h after the treatment. The spleen weight of mice given MLHPO tended to decrease. Spontaneous chemiluminescence of the thymus was remarkably increased after the dose. Thiobarbituric acid reactants in the liver, thymus and blood were also increased after the dose of MLHPO. At intervals of 3, 6, 12 and 24 h after a dose of 14C-labeled MLHPO, 14C was detected in the blood and liver. Fatty infiltration of the liver was found after the treatment with MLHPO. These findings indicate that oral intake of lipid hydroperoxides causes significant damage to lymphoid tissues of mice.

Administration, Oral↗
PubMed1988

Oxidation of lipids. XV. Role of hydrophilic diarylamines as antioxidants in the oxidations of lipids and biological tissues.

The abilities of two kinds of water-soluble diarylamines, disodium 4-chloro-2,2'-iminodibenzoate (CCA) and disodium 4-chloro-3',6'-dimethyl-2,2'-iminodibenzoate (CCM), to protect lipids, membranes and biological tissues from oxidative damages have been studied. The experimental systems studied include the oxidations of methyl linoleate micelles and soybean phosphatidylcholine (Pc) liposomal membranes in aqueous dispersions, oxidative hemolysis of rabbit erythrocytes, and the in vivo oxidative damages of biological tissues all induced by free radicals generated from an azo radical initiator. The two diarylamines functioned as moderate chain-breaking antioxidants and retarded the above oxidations.

Amidines↗
PubMed1988

Histopathological studies of experimental marine toxin poisoning. II. The acute effects of maitotoxin on the stomach, heart and lymphoid tissues in mice and rats.

Maitotoxin, one of the causative agents of ciguatera isolated from marine dinoflagellate, Gambierdiscus toxicus, induced severe pathomorphological changes in the stomach, heart and lymphoid tissues in mice and rats. Multiple erosions were observed in gastric mucosa accompanied by a marked increase in total calcium content 24 hr after i.p. injection of 200 or 400 ng/kg of maitotoxin. In contrast, there was no close temporal association between the accumulation of calcium and the morphological appearance of dead cells in the heart and thymus. Within 30 min of administration of 200 or 400 ng/kg of maitotoxin, a marked swelling was seen in the endothelial lining cells of blood capillaries between cardiac muscle fibers, followed by the cell death of the fibers. Injection of maitotoxin at a dose of 200 ng/kg or higher also resulted in necrosis of lymphocytes in the cortex of the thymus at 4 hr and in the medulla at 8 hr.

Animals↗
PubMed1988

Development of lymphocyte subsets in pigtailed macaques.

The early development of eight lymphocyte subsets was determined for pigtailed macaque infants from 0 to 800 days of age using two-color flow cytometry and fluorescein- and R-phycoerythrin-conjugated monoclonal antibodies specific for human leukocyte antigens. Four major lymphocyte subsets in monkeys (B, CD4+ T, CD8+ T, and NK cells) could be further divided using two-color analysis. In neonates, the frequency of lymphocyte subpopulations having surface phenotypes found principally on dense, resting cells (IgD+ B cells, Lp220+ CD4+ T cells, and CD18dull CD8+ T cells) was much higher than subpopulations having phenotypes present principally on buoyant, activated cells (IgD- B cells, Lp220- CD4+ T cells, CD18bri CD8+ T cells). There was a complete absence of two CD18bri CD8+ subsets (CD8dull and CD8bri) during the first 300 days of life. The relative proportion of lymphocyte subsets with resting phenotype decreased with increasing age, while the subpopulations associated with activation gradually increased with age. These findings suggest that during early development immunocompetent cells gradually differentiate into activated lymphocytes.

Age Factors↗
PubMed1988

Combined use of alpha-difluoromethylornithine and an inhibitor of S-adenosylmethionine decarboxylase in mice bearing P388 leukemia or Lewis lung carcinoma.

The antitumor and antimetastatic effects of alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, combined with an inhibitor of S-adenosylmethionine decarboxylase, either methylglyoxal bis(guanylhydrazone) (MGBG) or ethylglyoxal bis(guanylhydrazone) (EGBG), were studied in mice bearing P388 leukemia or Lewis lung carcinoma. Although EGBG is a more specific inhibitor of polyamine biosynthesis than the widely used MGBG, the antitumor effect of the DFMO-EGBG combination on P388 leukemia-bearing mice was less than that of the DFMO-MGBG combination. The prolongation of survival time by the DFMO(1000 mg/kg)-MGBG(25 mg/kg) combination was 2.65-fold, while that of the DFMO(1000 mg/kg)-EGBG(50 mg/kg) combination was 1.34-fold. When mice were fed a polyamine-deficient diet, stronger antitumor effects were exerted; the prolongation of survival time by the DFMO-MGBG and the DFMO-EGBG combinations was 2.89-fold and 2.03-fold, respectively. The antitumor effect of combined use of the two polyamine antimetabolites with mice on normal and polyamine-deficient diets correlated with a decrease of polyamine charge contents in the tumor cells. The above in vivo results were confirmed clearly in the KB cell culture system. The antimetastatic activity of DFMO on Lewis lung carcinoma-bearing mice was strengthened by the addition of MGBG or EGBG. The antimetastatic activity of the DFMO-MGBG or DFMO-EGBG combination did not parallel the polyamine charge contents in the primary tumor and blood.

Adenosylmethionine Decarboxylase↗