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Biomedical subjects

K Terao

Publications and source records attributed to K Terao.

At least 73 records · Page 4Linked to original sources
PubMed1996

In vitro immortalization of Old World monkey T lymphocytes with Herpesvirus saimiri: its susceptibility to infection with simian immunodeficiency viruses.

Peripheral blood T lymphocytes of Old World monkeys, rhesus and cynomolgus monkey (Macaca mulatta and Macaca fascicularis, respectively), were successfully immortalized by infection with Herpesvirus saimiri subtype C. The T cell lines were stably cultured without addition of exogenous IL-2. The STP-C488 protein, the oncogene product of subtype C strain 488-77, was detected in these cells by Western blotting. They also expressed some markers of activated or matured T cell phenotypes such as CD2+, monkey Pan-T+, CD25+,CD29+ and MHC-II DR+. Interestingly, not only CD4+CD8- or CD4-CD8+ single positive subpopulations but also CD4+CD8+ double positive ones were present in all of them. Furthermore, they were productively infected with both SIVmac and SIVagm. The levels of the viral replication were comparable to those in human T cell lines. Thus, Herpes Virus Saimiri-immortalized Old World monkey T lymphocytes will be suitable for further studies of immune system in Old World monkeys and cell-virus interactions in SIV infection.

Animals↗
PubMed1996

Morphological observations of diarrhea in mice caused by experimental ciguatoxicosis.

Diarrhea and morphological influences on digestive tracts caused by ciguatoxin (CTX) were observed in mice microscopically. The lethal doses and clinical symptoms caused by i.p. administration were almost the same as those by p.o., the prominent difference being diarrhea that was caused only by i.p. route. The diarrhea was caused by a dose from 1/7 MU to 1 MU of CTX (MU: mouse unit, to kill a mouse of 15 g in 24 hr, corresponding to 7 ng of pure CTX), but not at lower or higher doses. In this study, we used an i.p. dose of 4/5 MU (10.4 ng/28 g). Diarrhea started within 10 min after administration and lasted until 30 min. The changes were observed in the large intestine; namely, CTX accelerated mucus secretion and peristalsis in the colon and stimulated defecation at the rectum, resulting in prominent diarrhea. In the colon, a large quantity of mucus was secreted from even immature goblet cells, and epithelial cell damages were observed in the upper portion of the large intestine but not in the latter half. The morphological changes caused by CTX in the upper portion of the large intestine were similar to those seen with cholera toxin.

Animals↗
PubMed1996

Further study on association of 5SrRNA-L5 protein complex and methionyl-tRNA to methionyl-tRNA synthetase in the macromolecular aminoacyl-tRNA synthetase complex.

To obtain direct evidence for the attachment of 5SrRNA-ribosomal L5 protein particles (5SRNP) and methionine-tRNA (tRNA(met)) to methionyl-tRNA synthetase (MetRS) in the macromolecular aminoacyl-tRNA synthetase (ARS) complex of rat liver, a MetRS-5SRNP-tRNA(met) complex was dissociated from the macromolecular ARS complex fraction by n-octyl-beta-D-glucoside (Method I) or by omega-aminooctyl agarose (Method II) chromatography. The dissociated MetRS complex fraction was purified by gel filtration followed by tRNA-Sepharose chromatography using partially purified tRNA(met) in Method I, and by hydrophobic interaction chromatography in Method II. In both methods, final Superdex200 chromatography showed that MetRS activity was present in the region corresponding to the molecular weight of the MetRS-5SRNP-tRNA(met) complex (M(r) 200,000). One main protein band corresponding to the molecular weight of MetRS was observed on SDS-PAGE of the final product, which was concentrated by lyophilizing after dialysis against water. Using serum albumin as an inhibitor of adhesion of L5 to the microconcentrators which was used to concentrate the final product, a distinct L5 band was detected on SDS-PAGE, the intensity of which was comparable to that of the MetRS band. Northern blot analysis of RNA prepared from the tRNA-Sepharose fraction showed the presence of 5SrRNA. Dot blot analysis using an antibody against ribosomal protein L5 showed that L5 was present in the Superdex200 fractions prepared by both methods. The MetRS specific activities in MetRS complex fractions incubated without tRNA increased during the purification procedures, indicating that endogeneous tRNA(met) exists stably in the MetRS complex. 5SRNP and 5SrRNA markedly enhanced the MetRS activity in the MetRS complex, indicating that 5SRNP(A) plays a role as a positive effector of MetRS.

Amino Acyl-tRNA Synthetases↗
PubMed1996

Nonhuman primate models of measles.

Wild measles virus isolated in a marmoset lymphoblastoid B95a cell line induced rashes and Koplik's spots when inoculated parenterally in cynomolgus and squirrel monkeys. Marked leukopenia. associated with transient decrease in the CD4(+)-to-CD8+ T-cell ratio also was induced. Virus growth, as well as histologic lesions of necrosis and giant cell formation, was observed in the lymphoid tissues. Thus clinical signs of acute measles were successfully induced in monkeys by inoculation with cell-culture-grown measles virus. These nonhuman primate models of measles will be useful for study of the pathogenesis of acute measles virus infection in terms of generalized clinical signs of disease, leukopenia, and changes in the lymphocyte subsets.

Animals↗
PubMed1995

Hepatic damage induced by perfusion of radical generating azo compound and its inhibition by vitamin E.

The damaging effect of perfusion of hydrophilic radical generating azo compound on the liver of normal and vitamin E-deficient rats and its inhibition by antioxidants were studied in order to increase understanding of the action of free radicals on biological tissues. The hepatic damage was evaluated from the release of cytosolic enzymes such as glutamic oxaloacetic transaminase and glutamic pyruvic transaminase, mitochondrial oxidation metabolism and morphological change. Two kinds of hydrophilic azo compounds were used, one which decomposes spontaneously at a uniform rate to generate free radicals and the other which does not. The former induced hepatic damage in a dose-dependent manner, while the latter did not exert any damage. Both endogenous vitamin E in the membranes and a water soluble vitamin E analogue added simultaneously with a radical initiator suppressed the hepatic damage. These results show that the hepatic damage induced by perfusion of radical generating azo compound is caused not by the azo compound itself but by free radicals.

Alanine Transaminase↗
PubMed1995

Powerful hepatoprotective and hepatotoxic plant oligostilbenes, isolated from the Oriental medicinal plant Vitis coignetiae (Vitaceae).

The methanol extract of the Oriental medicinal plant Vitis coignetiae (Vitaceae) showed hepatoprotective activity in the in vitro assay method using primary cultured rat hepatocytes. Activity-guided fractionation of the extract afforded epsilon-viniferin as an active principle. The protective effect of epsilon-viniferin against mice carbon tetrachloride-induced hepatic injury in mice was shown by serum enzyme assay as well as by pathological examination. In addition to epsilon-viniferin, plant oligostilbenes, ampelopsins A, C, F and the mixture of vitisin A and cis-vitisin A were also present in the extract. Among them, ampelopsin C and the mixture of vitisin A and cis-vitisin A were found to be powerful hepatotoxins.

Animals↗
PubMed1995

Interaction of 5SrRNA-L5 protein complex, methionyl-tRNA, and methionyl-tRNA synthetase in the macromolecular ARS complex.

Rat liver cytosol was incubated with a trace amount of rat liver 5SrRNA which was highly labeled at the 3'-end with cytidine 3',5'-[5'-32P]biphosphate, and with [35S]methionine in the presence of ATP mixture, and then with an antibody against ribosomal protein L5. The mixture was analyzed by protein A-Sepharose chromatography. The following results were obtained. (i) The eluate with glycine-HCl buffer (pH 3.0) from the protein A-Sepharose column contained an overlapping peak of 32P- and 35S-radioactivities. In a control experiment using the same amount of 32P-labeled Escherichia coli 5SrRNA with the same specific activity, no fraction of the eluate contained 32P-radioactivity. (ii) The fractions containing both 32P- and 35S-radioactivities from the protein A-Sepharose column were crosslinked by UV irradiation. The products was subjected to PAGE, and RNA in each gel slice was eluted and purified. The fraction containing both 32P- and 35S-radioactivities was present in a region of somewhat higher molecular weight than that of 5SRNP, whereas very low 32P- and 35S-radioactivities were present in this region in the control experiment without UV irradiation. This finding suggested that [35S]methionyl-tRNA interacted with 32P-labeled 5SRNP. (iii) The fraction containing overlapping 32P- and 35S-radioactivities described above was subjected to Sephadex G-150 chromatography. The component containing both radioactivities was distributed in the region corresponding to molecular weights of 10,000 to 250,000 with a peak at about 200,000, suggesting the presence of a complex containing Met-RS (Mr 108,000), 5SRNP (Mr 74,000), and methionyl-tRNA (Mr 25,000). Furthermore, this fraction showed definite Met-RS activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acyl-tRNA Synthetases↗
PubMed1995

Diffuse laminar endocervical glandular hyperplasia.

A case is reported of diffuse laminar endocervical glandular hyperplasia, which is very rare among pseudoneoplastic endocervical glandular lesions. The patient was a 54 year old woman who had been suffering from watery vaginal discharge for about 7 years, and the lesion was found in the cervix of the hysterectomy specimen. Microscopically, the lesion showed a diffuse, laminar proliferation of hyperplastic endocervical glands, sharply demarcated from the underlying stroma. The significant nuclear atypia was absent. Inflammatory response was mild. Immunohistochemically, carcinoembryonic antigen was negative. Differential diagnosis from other non-neoplastic conditions and well differentiated adenocarcinoma is discussed.

Diagnosis, Differential↗
PubMed1995

Promotion by estriol of the development of grafted fetal livers in mice.

Mouse fetal livers of 12 days gestation were transplanted beneath the kidney capsule of syngeneic castrated male hosts. Recipients received a single intraperitoneal injection of 5 mg estriol (E3) immediately after transplantation and were sacrificed 4, 7 and 14 days later. Control mice received injections of solvent only. The fetal liver grafts of the E3 groups showed remarkable growth compared with the control grafts at each corresponding time. In the grafted fetal livers of the E3 groups, many more basophilic hepatocytes appeared for much longer periods, and the early formation of wide sinusoids was noted. Although hemopoietic activity had almost ceased a short time after transplantation in the control grafts, many prominent extrasinusoidal erythroid, granulocytic and megakaryocytic hemopoietic foci developed and persisted to the end of the experiments in the grafted fetal livers of the E3 groups. In the next experiment, the recipients received three injections of 0.5-5 mg E3 at 5-day intervals, and were sacrificed 21 days after transplantation. Control animals received solvent only in the same manner. The fetal liver grafts of the E3 groups also showed remarkable, dose dependent growth. The growth was particularly striking at doses of 3-5 mg E3. In the grafts of these groups, basophilic hepatocytes were predominant, and hepatic cords and sinusoids were well formed. Moreover, sinusoidal erythropoiesis was intense. These results provide evidence for the possible role of E3, secreted from the placenta into the fetal circulation, in the development of the fetal liver.

Animals↗
PubMed1994

Presence of role of the 5SrRNA-L5 protein complex (5SRNP) in the threonyl- and histidyl-tRNA synthetase complex in rat liver cytosol.

A complex containing Thr-RS and His-RS was purified about 1000 to 2000-fold from rat liver cytosol by successive column chromatographies on Sephadex G-200, Phenyl-Sepharose CL-4B, and tRNA-Sepharose. The ratio of the specific activity of Thr-RS and His-RS was relatively constant throughout the purification steps, suggesting that the two synthetases were co-purified as a complex. Chromatographic analyses of the tRNA-Sepharose fraction by Sephadex G-150 column chromatography showed the presence of a hybrid form of the Thr-RS monomer and the His-RS monomer in addition to dimer forms of both enzymes from the pattern of activity of both enzymes. The monomer form of Thr-RS showed high activity comparable to the dimer form and the monomer form of His-RS showed definite activity. An association form of Thr-RS and His-RS dimers was detected by Sephadex G-200 chromatography of rat liver cytosol. Northern blot analysis of RNA prepared from the tRNA-Sepharose fraction showed the presence of 55SrRNA blot analysis of the tRNA-Sepharose fraction using an antibody against ribosomal protein L5, showed the presence of ribosomal protein L5 in this fraction. These findings suggest that the presence of a 5SRNA-L5 protein complex (5SRNP) in the Thr-RS and His-RS complex. 5SRNP enhanced the activity of Thr-RS in a freshly prepared tRNA-Sepharose fraction. It also enhanced the activity of the rat liver cytosol for the attachment of [3H]threonine to endogenous tRNA. This activity was inhibited by an antibody against protein L5, and the inhibition was reversed by addition of 5SRNP. These results indicate that 5SRNP plays a role as a positive effector of Thr-RS in the complex.

Animals↗
PubMed1994

Effects of pectenotoxin-1 on liver cells in vitro.

The effects of pectenotoxin-1 (PTX1), a nondiarrheagenic toxin from mussels, on liver cells were investigated by fluorescence microscopy. The in vitro application of PTX1 to these cells induced reduction in number and loss in radial arrangement of microtubules. It also induced disruption of stress fibers and accumulation of actin at the cellular peripheries. Further studies are worthwhile to explore the feasibility of using PTX1 as a tool for analyzing the properties of cytoskeletal proteins.

Animals↗
PubMed1994

Electron microscopic studies on experimental poisoning in mice induced by cylindrospermopsin isolated from blue-green alga Umezakia natans.

The effects of cylindrospermopsin isolated from a blue-green alga Umezakia natans on mice were examined morphologically and biochemically. The main target of the phycotoxin was the liver. The thymus, kidneys and heart were also affected. There were four consecutive phases of the pathological changes in the liver. The initial phase was that of inhibition of the protein synthesis, the second phase of membrane proliferation followed, and then the third phase of fat droplet accumulation and finally the phase of cell death. Using globin synthesis in the rabbit reticulocytes system, it was clearly demonstrated that cylindrospermopsin is a potent inhibitor of the protein synthesis. Protein in microsomes from the mouse livers treated by cylindrospermopsin decreased in amount more significantly than that of phospholipid in microsomes. Furthermore, the amount of total P450 was extensively diminished in the toxin treated with hepatic microsomes.

Alkaloids↗
PubMed1994

Isolation of cylindrospermopsin from a cyanobacterium Umezakia natans and its screening method.

In 1987 a cyanobacterium (blue-green alga) Umezakia natans was isolated from Lake Mikata, Fukui, Japan, as a new member of the family of Stigonemataceae. The crude extract of U. natans showed hepatotoxicity to mice, from which a toxic compound was isolated. The toxin was identical in all respects to a recently reported hepatotoxin, cylindrospermopsin, isolated from an Australian tropical cyanobacterium Cylindrospermopsis raciborskii. Because cylindrospermopsin causes fatty liver and central necroses in mice and is suspected of being an agent causing human hepatoenteritis, its monitoring in drinking water supplies has been required. So a rapid screening method including four steps, extraction, clean-up, separation, and determination, has been proposed for cylindrospermopsin. A combination of a clean-up using HP-20 and C18-cartridge, and HPLC with photodiode array detector made it possible to establish a screening method for the toxin. The established method was applied to five samples and cylindrospermopsin was traced in one of them.

Alkaloids↗
PubMed1994

Purification and characterization of a novel acrosin-like enzyme from boar cauda epididymal sperm.

A trypsin-like protease was extracted with 1% cetyltrimethylammonium bromide (CTAB) at pH 7.0 from boar cauda epididymal sperm nuclei whose acrosin had previously been removed by acid extraction. The CTAB-extracted sperm protease (CSP) was purified by ion-exchange chromatography on CM-23, gel filtration on Sephadex G-100, affinity chromatography on benzamidine-CH-Sepharose 4B, and HPLC on CM-5PW. CSP is a two chain protein composed of M(r) 2.6K and M(r) 37K chains, which are covalently cross-linked by disulfide bonds. CSP exhibited a pH optimum between pH 8.0 and 9.0, and was inhibited by diisopropyl phosphorofluoridate, antipain, leupeptin, and 1-chloro-3-tosylamide-7-amino-L-2-heptanone. The activity of CSP was enhanced about 1.2-fold with 50 mM CaCl2, with which acrosin is enhanced 2.0-fold. The catalytic efficiency (kcat/Km) of CSP toward Bz-L-Arg-OEt, Tos-L-Arg-OMe, and Tos-L-Lys-OMe in the presence of 50 mM CaCl2 differed from that of acrosin by factors of 0.53, 1.2, and 0.80, respectively. Amino acid sequencing of V8-digested peptides of CSP, and its L- and H-chains showed that the amino acid sequence of CSP was closely related to, but different from, that of acrosin. These results suggest that CSP is a novel acrosin-like enzyme that differs from acrosin in its location in the sperm head, the effect of calcium ions on its activity, and its substrate specificity.

Acrosin↗
PubMed1994

Cryopreservation of spermatozoa from cynomolgus monkeys (Macaca fascicularis).

Fertilization of eggs from cynomolgus monkeys (Macaca fascicularis) was achieved in vitro using frozen-thawed spermatozoa. The best sperm survival rate was obtained after freezing spermatozoa in a semen-diluting medium (TTE: Tes, Tris, egg yolk base) containing 5% glycerol with 30 min equilibrium time. Although frozen-thawed spermatozoa could fertilize eggs in vitro and some of the fertilized eggs developed into blastocysts or hatched blastocysts, a sperm fertility assay using salt-stored eggs indicated that frozen-thawed spermatozoa had a shorter lifespan in capacitation medium than did fresh, unfrozen spermatozoa. This may be attributable to damage to their plasma membranes.

Animals↗
PubMed1994

The immune function and measles virus infection in three different socioeconomic child populations in Karachi, Pakistan.

The immune function as well as anti-measles virus antibody level were investigated with 111 children in Karachi who were classified into high-, middle- and low-income groups. No difference in the blood cell counts or the biochemical data among three groups indicates no marked difference in the general health conditions among them. In the low-income group, levels of IgG, IgA and anti-measles virus antibody were significantly higher than those in the other two groups. Although 30% of children of the low-income group kept extremely high levels of immunoglobulin, no significant correlation was observed between IgG levels and anti-measles virus antibody levels. In the high-income group, the level of IgM was significantly lower and the incidence of anti-measles virus antibody-negative children was high (7/38; 18.4%). These antibody-negative children kept lower immunoglobulin levels although they were over four years old. These results suggest that the living environmental conditions of these different socioeconomic groups vary greatly and hygienic conditions must influence the chance of encountering infectious pathogens including measles virus. The relation between living environment and risk of subacute sclerosing panencephalitis (SSPE) in child population of Krachi is discussed.

Antibodies, Viral↗