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Biomedical subjects

T Ono

Publications and source records attributed to T Ono.

At least 811 records · Page 45Linked to original sources
PubMed1991

Primary structure of a 15-kDa protein from rat intestinal epithelium. Sequence similarity to fatty-acid-binding proteins.

An abundant and novel cytosolic protein was purified from the rat intestinal epithelium by gel filtration, ion-exchange and hydroxylapatite chromatography. The protein was eluted into two different positions (fractions 1 and 2) on DEAE-cellulose chromatography. We have completed the primary structure of the protein of fraction 1 by Edman degradation. The protein (144565 Da) contains 127 amino acid residues and has an acetylated alanine at its NH2-terminus. Comparison of the primary structure of the protein with porcine gastrotropin [Walz, A. D., Wider, M. D., Snow, J. W., Dass, C. & Desiderio, D. M. (1988) J. Biol. Chem. 263, 14189-14195] and rat hepatic fatty-acid-binding protein revealed that identical residues within these proteins are found in 90 and 54 out of a total of 127 positions, respectively. Bioactivity studies demonstrated that neither the protein nor liver and intestinal fatty-acid-binding proteins influence gastric acid secretory activity in rats with gastric fistulas compared to pentagastrin. The protein showed very low affinity for palmitic-acid-binding in vitro assay system and only trace amounts of endogenous fatty acids were detected from the protein. The protein, rat intestinal 15-kDa protein is considered to be a new member of the fatty-acid-binding protein family based on its structural features.

Amino Acid Sequence↗
PubMed1991

Fluorimetric determination of mexiletine in serum by high-performance liquid chromatography using pre-column derivatization with fluorescamine.

A simple, specific and sensitive micro-scale method for the assay of the antiarrhythmic agent mexiletine in human serum is described. The method uses high-performance liquid chromatography, with pre-column fluorimetric derivatization by fluorescamine. Following extraction with diethyl ether, mexiletine and 4-methylmexiletine (an internal standard) were derivatized with fluorescamine under weakly alkaline condition (pH 9.0) and chromatographed on a reversed-phase column with aqueous methanol-2-propanol as the mobile phase. The two fluorescent derivatives of mexiletine and the internal standard were separated as clear single peaks, and no interfering peaks were observed on the chromatograms. The detection limit for mexiletine was 0.005 micrograms/ml from only 100 microliters of serum, and the calibration curves in the range 0.01-5 micrograms/ml were linear, with an overall coefficient of variation of less than 5%. The analytical recovery of a known amount of mexiletine added to serum was almost 100%. This method proved to be effective in the rapid monitoring of the serum concentrations in patients who received this potent antiarrhythmic drug.

Anti-Arrhythmia Agents↗
PubMed1991

Primary structure and cellular distribution of two fatty acid-binding proteins in adult rat kidneys.

Fatty acid-binding proteins (FABPs) were purified from the kidneys of female and male rats and characterized by primary structure and histological distribution in the kidney. Two FABPs (14 and 15.5 kDa) were found in male rat kidney cytosol whereas only 14-kDa FABP could be recognized in female rat kidneys throughout the purification steps. The amino acid sequence of the 14-kDa FABP was identical to that of rat heart FABP deduced from the cDNA sequence (Heuckeroth, R. O., Birkenmeier, E. H., Levin, M. S., and Gordon, J. I. (1987) J. Biol. Chem. 262, 9709-9717). Structural analysis of the male-specific 15.5-kDa FABP identified this second FABP as a proteolytically modified form of alpha 2u-globulin, an 18.7-kDa major urinary protein of adult male rats (Unterman, R. D., Lynch, K. R., Nakhasi, H. L., dolan, K. P., Hamilton, J. W., Cohn, D. V., and Feigelson, P. (1981) Proc. Natl. Acad. Sci. U.S.A. 78, 3478-3482) which shares a common ancestry with a number of hydrophobic ligand-binding proteins such as serum retinol-binding proteins. Immunohistochemical investigation disclosed that heart-type FABP (14-kDa FABP) is localized in the cytoplasm of the epithelia of the distal tubules in both male and female rat kidneys whereas 15.5-kDa FABP immunostaining was observed predominantly in the endosomes or lysosomes of proximal tubules in male rat kidneys. These results suggest strongly the functional divergence of two FABPs in the rat kidney.

Amino Acid Sequence↗
PubMed1991

Biochemical evidence for histidine oxidation in photosystem II depleted of the Mn-cluster for O2-evolution.

Flash excitation of Tris-treated photosystem II (PSII) membranes generated a thermoluminescence band peaking at -20 degrees C, indicating that a positively charged oxidizing equivalent is stably accumulated on donor side of PSII even in the absence of the Mn-cluster. This oxidizing equivalent was sensitive to low concentrations of exogenous Mn2+, and its stable accumulation was reversibly inhibited by diethylpyrocarbonate treatment that modifies histidine residues with high specificity. It was inferred that there is a photooxidizable histidine residue(s) on donor side of PSII and it provides a redox-active ligand for Mn.

Diethyl Pyrocarbonate↗
PubMed1991

Place recognition responses of neurons in monkey hippocampus.

Neuronal activity in the monkey hippocampus was recorded while the monkey sat in a rotatable cab which it could cause to move from one location to another by pressing bars, and while it was presented various visual stimulation from several horizontal directions (directional stimulation). Of 174 hippocampal neurons recorded, 20 were selective to direction of the stimulus without place relation. Responses of these neurons could be described in egocentric coordinates for some and allocentric coordinates for others. Seventy-seven neurons had place related activity (place related neurons). Of these place related neurons, 21 were also directionally selective with responses described in egocentric or allocentric coordinates or both. The results show close relations between the coding of environmental space cues in egocentric and allocentric coordinates, and place related activity in the primate hippocampus.

Animals↗
PubMed1991

Ontogenic appearance of three fatty acid binding proteins in the rat stomach.

With the use of specific antibodies against three structurally different fatty acid binding proteins (FABPs), viz, liver FABP (L-FABP), heart FABP (H-FABP), and intestinal FABP (I-FABP), the localization and relative amount of the immunoreactive proteins were determined by immunoblotting and immuno-cytochemistry in the gastric epithelium of rats during prenatal and postnatal development. H-FABP immunoreactivity was first detected at embryonic day 20 (E20), with predominant localization in the parietal cells, whereas I-FABP immunoreactivity was detected at the day of birth in the surface mucous cells. Both immunoreactivities were continuously localized in the same cell types with increasing intensity into adulthood. In contrast, the immunoreactivity for L-FABP showed remarkable changes in intensity and localization during development of the rat stomach. It was first detected in the surface mucous cells of E19. In the first 2 weeks of postnatal life, i.e., the suckling period, L-FABP immunoreactivity reached a peak in intensity and was localized not only in the surface mucous cells, but also in some of the parietal cells, brush cells, and endocrine D cells. In the following few weeks of weaning, the reactivity of surface mucous cells and parietal cells disappeared, leaving only a small amount of total L-FABP immunoreactivity in the adult stomach, which was localized exclusively in the brush cells and D cells. These results revealed that the appearance of the three types of FABPs in the rat stomach is specific to cell types and developmental stages.

Animals↗
PubMed1991

Vitamin D and chick embryonic yolk calcium mobilization: identification and regulation of expression of vitamin D-dependent Ca2(+)-binding protein, calbindin-D28K, in the yolk sac.

The developing chick embryo acquires calcium from two sources. Until about Day 10 of incubation, the yolk is the only source; thereafter, calcium is also mobilized from the eggshell. We have previously shown that during normal chick embryonic development, vitamin D is involved in regulating yolk calcium mobilization, whereas vitamin K is required for eggshell calcium translocation by the chorioallantoic membrane. We have studied here the biochemical action of 1,25-dihydroxy vitamin D3 in the yolk sac by examining the expression and regulation of the cytosolic vitamin D-dependent calcium-binding protein, calbindin-D28K. Two types of embryos are used for this study, normal embryos developing in ovo and embryos maintained in long-term shell-less culture ex ovo, the latter being dependent solely on the yolk as their calcium source. Our findings are (1) calbindin-D28K is expressed in the embryonic yolk sac, detectable at incubation Days 9 and 14; (2) the embryonic yolk sac calbindin-D28K resembles that of the adult duodenum in both molecular weight (Mr 28,000) and isoelectric point, as well as the presence of E-F hand Ca2(+)-binding structural domains; (3) systemic calcium deficiency caused by shell-less culture of chick embryos results in enhanced expression of calbindin-D28K in the yolk sac during late development; (4) yolk sac calbindin-D28K expression is inducible by 1,25-dihydroxy vitamin D3 treatment in vivo and in vitro; and (5) immunohistochemistry revealed that yolk sac calbindin-D28K is localized exclusively to the cytoplasm of the yolk sac endoderm. These findings indicate that the chick embryonic yolk sac is a genuine target tissue of 1,25-dihydroxy vitamin D3.

Animals↗
PubMed1991

Role of inflammatory responses in initiation of atherosclerosis: effects of anti-inflammatory drugs on cuff-induced leukocyte accumulation and intimal thickening of rabbit carotid artery.

Immediately after a cuff-sheathing of rabbit carotid artery, a large number of leukocytes adhered to injured endothelium then infiltrated into the media. These inflammatory responses were followed by an atherosclerotic change, intimal thickening, of the artery. A simultaneous injection of dexamethasone (10 mg/kg i.m.) inhibited the leukocyte accumulation by 74% when evaluated 18 h thereafter. Similarly, 39% inhibition was obtained with the same dose of FR110302, a potent 5-lipoxygenase inhibitor. On the other hand, the same dose of indomethacin, a cyclooxygenase inhibitor, had little effect on the leukocyte accumulation. The intimal thickening which was evaluated 3 weeks after the cuff-treatment was attenuated by a daily dose (10 mg/kg i.m.) of dexamethasone or FR110302 but not by one of indomethacin. The inhibition by the two former drugs were 91 and 58%, respectively. In vitro, the three drugs in concentrations up to 10 microM hardly affected endothelial adhesion of PMN which was induced by LPS or IL-1. Though 10 microM of FR110302 and indomethacin significantly decreased PMN chemotaxis induced by LTB4, the decreases were less than that at 10 microM dexamethasone. These results confirm a possible linkage between inflammation and atherosclerosis, and suggest that 5-lipoxygenase products contribute to the initiation and development of atherosclerosis.

Animals↗
PubMed1991

Amino acid and NaCl appetite, and LHA neuron responses of lysine-deficient rat.

Rats' preferences for amino acids and NaCl in their drinking behavior were noted when they were fed either a control diet of gluten plus 20% purified egg protein, or (same rats, different time) a lysine-deficient diet. In control, the order of the rats' preferences was arginine greater than saline greater than monosodium L-glutamate (MSG, umami) greater than glycine greater than water greater than threonine greater than histidine greater than lysine. When fed a lysine-deficient diet the order of preference was lysine greater than saline greater than MSG greater than glycine greater than threonine greater than water greater than arginine greater than histidine. To relate neural activity with preference for amino acids and NaCl, activity of lateral hypothalamic (LHA) neurons was recorded during ingestion of MSG, lysine, arginine, glycine, saline, glucose, or water by the control and lysine-deprived condition, following a different cue tone. When the diet was lysine deficient, some neurons responded specifically to lysine ingestion. More neurons responded nondifferentially during licking in control, and responded to lysine, but fewer to other amino acid ingestion during lysine deficiency. Responses to cue tone were associated with those during licking. The present results suggest that preference for deficient amino acids might be mediated in the LHA.

Amino Acids↗
PubMed1991

Parabrachial gustatory neural responses to monosodium glutamate ingested by awake rats.

A sample of 41 gustatory neurons isolated in the parabrachial nuclei of awake, behaving rats was tested with sapid solutions of 0.1 M monosodium glutamate (MSG), 0.5 mM of guanosine 5'-monophosphate (GMP), and a mixture of MSG and GMP as well as with 0.3 M sucrose, 0.1 M NaCl, 0.01 M citric acid, and 0.0001 M QHCl. Interneuronal correlation coefficients and factor analysis indicated that both the sodium cation and glutamic anion contributed to the activity elicited by MSG. Guanosine potentiated the responses to MSG, but only in neurons that also responded to sucrose. These results suggest that the gustatory contribution to the flavor denoted by the Japanese word "umami" may be mediated, in part, by neurons that also respond to chemical described by humans as sweet.

Animals↗
PubMed1991

Taste preference and protein nutrition and L-amino acid homeostasis in male Sprague-Dawley rats.

Changes in taste preference were investigated in a choice paradigm using rats under various states of protein nutrition. A preference for the umami taste substances, monosodium L-glutamate (MSG) with or without 5'-ribonucleotide (5'-guanosine monophosphate), was induced when dietary protein was within the normal range, but a preference for NaCl occurred under its marginal deficiency. A preference for both NaCl and glycine was induced under severe protein malnutrition, possibly reflecting the body's negative nitrogen balance. The strength of this preference paralleled the body's requirement for protein, and thus, like the protein requirement for normal growth, declined with age. When animals with L-lysine (Lys) deficiency consumed a Lys solution and began to grow normally, their intake of taste stimulus solutions changed from preferring NaCl and glycine to preferring MSG. The regulatory mechanism of preference for L-amino acid (AA) in rats deficient of an essential AA was related to the pattern of AA in plasma and brain. Data suggest that umami taste perception plays an important role in protein metabolism, and in maintenance of AA and ammonia homeostasis within normal limits.

Amino Acids↗
PubMed1991

Malignant schwannoma associated with xeroderma pigmentosum in a patient belonging to complementation group D.

A 43-year-old man with xeroderma pigmentosum, XP97TO, was allocated to complementation group D. He had had moderate photosensitivity at age 1 year and freckles by age 6 but no neurologic abnormalities. Nevertheless, his fibroblasts in culture had the XP-D phenotype. They showed a sevenfold hypersensitivity to killing by 254 nm ultraviolet radiation and a diminished level (29%) of unscheduled DNA synthesis. Phototesting revealed delayed maximum erythema at 72 hours after UVB exposure and a lowered minimal erythema dose. Lentigo maligna developed on the patient's face, and a rapidly growing malignant schwannoma was found on the left trigeminal nerve. This may be the first case of a peripheral nervous tissue neoplasm in xeroderma pigmentosum.

Adult↗
PubMed1991

Construction of a 7-aminocephalosporanic acid (7ACA) biosynthetic operon and direct production of 7ACA in Acremonium chrysogenum.

We have used cDNA encoding D-amino acid oxidase, and genomic DNA encoding cephalosporin acylase from Fusarium solani and Pseudomonas diminuta, respectively, to construct a novel hybrid 7-aminocephalosporanic acid (7ACA) biosynthetic operon under the control of regulatory elements from the alkaline protease gene of Acremonium chrysogenum. Transformants of A. chrysogenum BC2116, a high cephalosporin-producing strain, containing this operon, synthesized and secreted low levels of 7ACA. Although the amounts are not yet commercially significant, this represents the first microbial production of 7ACA and demonstrates the feasibility of introducing new biosynthetic capabilities into industrial microorganisms by combining fungal and bacterial genes.

Acremonium↗
PubMed1991

Post-irradiation treatment with OK432 can prevent radiation-induced bone marrow death.

The radioprotective effect of OK432, a Streptococcus haemolyticus preparation, on bone marrow death was examined in mice. The LD50 value was increased from 7.55 Gy in controls to 8.45 Gy in mice treated once with OK432 immediately after irradiation. Multiple administrations of the agent further elevated the LD50 value to 9.56 Gy. The radioprotective effect was also apparent when multiple treatments were commenced as late as 72 h after irradiation.

Animals↗
PubMed1991

Striae distensae after tension-requiring skin sutures.

Three cases of striae distensae which developed along suture scars after skin surgery were described. The production of striae should be taken into consideration in surgery of the skin, especially in young woman.

Adolescent↗
PubMed1991

Late onset dermal melanocytosis: an upper back variant.

Seven elderly Japanese men with blue macules on their upper backs are reported. Histological examination showed this pigmentation to be melanosis due to the presence of spindle-shaped or oval pigment-laden cells in the dermis. Electron microscopy revealed the cells to be compatible with dermal melanocytes. We assume that this condition belongs to the category of late onset dermal melanocytosis and is an upper back variant. This concept has not been proposed before.

Aged↗