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Biomedical subjects

T Tsuchiya

Publications and source records attributed to T Tsuchiya.

At least 649 records · Page 36Linked to original sources

[The influence of ileo-jejunal transposition on intestinal mucosal growth and gut hormones after total colectomy].

To clarify the effect of ileo-jejunal transposition on intestinal mucosal height and gut hormones, canine models undergoing total colectomy either with transection of the small intestine (control group) or ileo-jejunal transposition (transposition group) were compared, and the following results were obtained. There was no difference in body weight between control group and transposition group 18 weeks after operation. Significant increase of mucosal height was observed in transposition group but not in control group. Plasma levels of total GLI were significantly higher in transposition group but not in control group, whereas a count of GLI secreting cell was not changed in both groups. Plasma levels of gastrin after test meal were lower in transposition group than in control group. These results indicated that ileo-jejunal transposition induces hyperenteroglucagonemia, which may play an important role in intestinal adaptation after colectomy.

Adaptation, Physiological↗

[Health check by CMI (Cornell Medical Index) on radiation workers in a nuclear energy plant].

In the nuclear energy industry, plants are located far from urban areas and the working environments are generally separate from each other for radiation protection purposes. A health check on radiation workers in the nuclear energy industry was carried out using the Cornell Medical Index questionnaire. As a control study, radiation and non-radiation workers in the other working fields were investigated in the same manner. The results showed that the health status of radiation workers in the nuclear energy industry is similar to that of the workers in other working fields.

Adult↗

Reflex changes in sympatho-adrenal medullary functions in response to various thermal cutaneous stimulations in anesthetized rats.

The effects of various thermal stimulations of restricted skin areas with a thermal probe on the adrenal sympathetic efferent nerve activity and catecholamine (CA) secretion rates from the adrenal medulla were studied in alpha-chloralose-urethane anesthetized rats. Both cold and warm stimulations of abdominal skin either below 10 degrees C or above 43 degrees C produced reflex increases in nerve activity as well as CA secretion rates, whereas stimulations between 13 degrees C and 40 degrees C were ineffective in producing significant changes in these variables. The stimulation of chest and abdominal skin areas was more effective in producing adrenal sympathetic nerve responses than that of the shoulder, thigh or scrotum skin.

Adrenal Medulla↗

JTC-11 cells derived from Ehrlich ascites tumor deficient in a growing medium containing citrulline.

JTC-11 cells derived from an Ehrlich ascites tumor do not proliferate and do not synthesize DNA in a medium which contains citrulline but not arginine. Mouse L and HeLa cells grew well in citrulline medium. Since JTC-11 cells have been transplanted intraperitoneally in vivo and cultured in vitro for a long period, these cells may spontaneously lose the ability to synthesize arginine from citrulline.

Animals↗

In vivo inhibition of adenosine triphosphate (ATP) synthesis associated with thiabendazole-induced teratogenesis in mice and rats.

Ogata et al. (1984) reported that thiabendazole (TBZ) was teratogenic in mice when olive oil was used as a vehicle, but not teratogenic when administered in gum arabic. Results of investigations into the possible association between TBZ-induced teratogenicity and adenosine triphosphate (ATP) are reported here. ATP levels in the limb buds were measured at day 10 of gestation in controls and mice treated with 1300 mg/kg TBZ 24 h previously. The results showed that there was a correlation between the dosage of TBZ and the ATP levels of fore and hind limb buds (r = -0.827 and r = -0.799, respectively). ATP levels in mouse limbs were reduced to 22-31% of control values when TBZ was given in olive oil, but the ATP reduction was only 6-9% when TBZ was given in gum arabic. This suggests that there may be a relationship between the teratogenic and ATP-depressing action of TBZ on the limb buds of mouse embryos. Pregnant rats were also treated with TBZ. TBZ at a dose level of 1000 mg/kg was given orally on day 11 of gestation. After 24 h, ATP levels in fetal rat limbs were still 82% of control values. These results confirm the observations of Ogata et al. on the vehicle effect and the difference in response between mice and rats.

Adenosine Triphosphate↗

Na+ (Li+)-proline cotransport in Escherichia coli.

Na+ and Li+ were found to stimulate the transport of L-proline by cells of Escherichia coli induced for proline utilization. The gene product of the put P gene is involved in the expression of this transport activity since the put P+ strains CSH 4 and WG 148 show activity and the put P- strain RM 2 fails to show this cation coupled transport. The addition of proline was found to stimulate the uptake of Li+ and of Na+. Attempts to demonstrate proline stimulated H+ uptake were unsuccessful. It is concluded that the proline carrier (coded by the put P gene) is responsible for Na+ (or Li+)-proline cotransport.

Biological Transport, Active↗

Purification and characterization of an antibacterial factor from snail mucus.

The antibacterial factor from the body surface of the African giant snail, Achatina fulica Férussac, was isolated by DEAE-Toyopearl 650M ion exchange chromatography. The isolated preparation exhibited highly positive antibacterial activity both for the Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus and for the Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, but it lost such activity when heated at 75 degrees C for 5 min. The antibacterial factor of the snail mucus was a glycoprotein whose molecular weight (MW) was about 160,000. It was composed of two subunits of MW 70,000-80,000.

Animals↗

Change of inhibitor sensitivities of Escherichia coli F1-ATPase due to a mutational substitution of Phe for Ser at residue 174 of the beta subunit.

The F1-ATPase from the uncD11 mutant of E. coli (Kanazawa, H., Horiuchi, Y., Takagi, M., Ishino, Y., & Futai, M. (1980) J. Biochem. 88, 695-703), showed different enzymological properties from the wild-type enzyme. The mutant F1-ATPase had biphasic kinetics and essentially the same Km values as the wild-type enzyme, although its Vmax values were lower. The mutant enzyme showed altered sensitivities to dicyclohexylcarbodiimide (DCCD), azide and quercetin; it was less sensitive than the wild-type to quercetin and DCCD, and its Mg2+-dependent ATPase activity was slightly more resistant to azide than that of the wild-type, whereas its Ca2+-dependent activity was more sensitive. On the other hand, the mutant and wild-type F1 were inhibited equally by 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl). The fact that the Mg2+- and Ca2+-dependent F1-ATPase activities of the wild-type and mutant responded differently to quercetin and azide suggested that their mechanisms of action were different. Previous studies (Noumi, T., Mosher, M.E., Natori, S., Futai, M., & Kanazawa, H. (1984) J. Biol. Chem. 259, 10071-10075) indicated that Ser is replaced by Phe at residue 174 of the beta subunit of the mutant. Thus the Ser residue or its neighboring area(s) may constitute the binding site of DCCD, quercetin and azide.

Amino Acid Sequence↗

Value of heptyl-beta-D-thioglucoside, a new nonionic detergent, in studies on membrane proteins.

A new nonionic detergent, heptylthioglucoside, was synthesized and found to be more soluble than octylthioglucoside in water at low temperatures. Use of this detergent for solubilization and reconstitution of membrane proteins of Escherichia coli was examined. Heptylthioglucoside was as effective as octylthioglucoside and octylglucoside in solubilizing membrane proteins, and by the heptylthioglucoside-dilution procedure the H+-translocating ATPase (F1F0) and melibiose carrier could easily be reconstituted into liposomes. It is concluded that heptylthioglucoside is very useful in studies on membrane proteins.

Bacterial Proteins↗

Electron microscopy of granulomatous lesions of the liver in primary biliary cirrhosis.

Three granulomas in the portal tract and 9 bile ducts with typical features of chronic non-suppurative destructive cholangitis (CNSDC) associated with dispersed epithelioid cells were examined by electron microscopy in 10 patients with primary biliary cirrhosis (PBC). Vesicular epithelioid cells, which contained numerous single-membrane bound vesicles, predominated in the granulomas. On the other hand, immature epithelioid cells and activated macrophages were more often observed near epithelial cells of the bile ducts with CNSDC than in the granulomas. These macrophages seemed to be activated by epithelial cells of the bile ducts and develop into epithelioid cells. Honeycomb-like membranous labyrinths containing electron dense substances were frequently observed in epithelioid cells and were likely a special form of phagosome. The substances in the labyrinths seemed to be derived from organellae of necrotic cells and extracellular interstitial tissues. Subplasmalemmal linear densities (SPLD) were observed at the cytoplasmic boundary and at intracytoplasmic membranous labyrinth. The roles of SPLD were discussed.

Epithelium↗

Escherichia coli mutants possessing an Li+-resistant melibiose carrier.

Escherichia coli K-12 strains in the absence of the lactose carrier grew on the disaccharide melibiose as the sole source of carbon. The presence of 0.1 mM Li+ in the medium strongly inhibited growth of such cells, and Li+-resistant mutants appeared after several days of incubation. These mutants showed altered cation coupling to melibiose transport via the melibiose carrier. Cotransport between H+ and melibiose was lost in the mutants, although Na+-melibiose cotransport was retained. We observed no Li+-melibiose cotransport. Therefore, these mutants represent a new type of cation-coupling mutants of the melibiose carrier.

Biological Transport↗

Respiration-driven Na+ pump and Na+ circulation in Vibrio parahaemolyticus.

Sodium circulation in Vibrio parahaemolyticus was investigated. We observed respiration-driven Na+ extrusion from cells by using a Na+ electrode. The Na+ extrusion was insensitive to a proton conductor, carbonyl cyanide m-chlorophenylhydrazone, and sensitive to a respiratory inhibitor, CN-. These results support the idea of the existence of a respiratory Na+ pump in V. parahaemolyticus. The respiration-driven Na+ extrusion was observed only under alkaline conditions.

Amino Acids↗

Alteration in cation specificity of the melibiose transport carrier of Escherichia coli due to replacement of proline 122 with serine.

The structural genes (melB) for the melibiose carrier of five mutants of Escherichia coli showing altered cation specificity for melibiose transport were cloned. The mutations were mapped in a 248-base-pair DNA fragment by a recombinational assay by using the mutants transformed with hybrid plasmids carrying various portions of the wild-type melB gene. The nucleotide sequences of the corresponding DNA fragments derived from mutated melB genes were determined, and the amino acid sequences of the carrier were deduced. Proline 122 was replaced with serine in the melibiose carrier of all five mutants (which were isolated independently). We conclude that this amino acid replacement caused the alteration in cation specificity (loss of coupling to H+) of the melibiose carrier.

Amino Acid Sequence↗

Scanning electron microscopy and the study of Fc and C3b receptors of cultured fat-storing cells from rat liver.

Non-parenchymal fat-storing cells (FSCs) were isolated from rat liver by Metrizamide density centrifugation after liver perfusion with media containing pronase and/or collagenase. These cells were cultured in Williams' E medium with 20% fetal calf serum under the usual conditions. FSCs, identified by vitamin A-specific fluorescence (VAF), were viewed under conventional light microscopy 24, 48 and 72 h after seeding. At 24 h, some FSCs remained hemispheric; at 48 h all FSCs were well spread out, and at 72 h the number of FSCs had increased and the VAF intensity had become weaker. Scanning electron microscopy revealed that the features of the FSCs clearly differed from those of the other non-parenchymal cells. The in vitro FSC features closely resembled the in vivo features. FSCs cultured for 48 h had flattened, triangular or oval shapes with fairly smooth surfaces that showed scattered microvilli 0.1 micron long. Two types of processes, long slender (130 microns maximum length) and short broad ones, protruded from the cell body. These processes had smaller projections 0.2 micron wide that looked like fern leaves. Many lipid droplets could be seen under the cell surface. IgG-coated sheep erythrocytes (EAs) and IgM-C3-coated ox erythrocytes (EACs) were used to investigate whether there are Fc and C3b receptors on the FSCs. No rosette-formation characteristic of EAs or EACs was present on the FSCs; proof that FSCs have neither receptor.

Animals↗