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T Horiuchi

Publications and source records attributed to T Horiuchi.

At least 415 records · Page 23Linked to original sources
PubMed1987

Molecular cloning and nucleotide sequence of the mutT mutator of Escherichia coli that causes A:T to C:G transversion.

The Escherichia coli mutator gene mutT, which causes A:T----C:G transversion, was cloned in pBR 322. mutT+ plasmids carry a 0.9 kb PvuII DNA fragment derived from the E. coli chromosome. Specific labelling of plasmid-encoded proteins by the maxicell method revealed that mutT codes for a polypeptide of about 15,000 daltons. The protein was overproduced when the mutT gene was placed under the control of the lac regulatory region on a multicopy runaway plasmid. The nucleotide sequence of the mutT gene was determined by the dideoxy method.

Amino Acid Sequence↗
PubMed1987

Replication intermediate of a hybrid plasmid carrying the replication terminus (ter) site of R 6K as revealed by agarose gel electrophoresis.

A 4.32 kb DNA fragment, on which the DNA replication terminus (terR) site of plasmid R 6K was located, was inserted into the unique EcoRI site of plasmid pUC9. To detect replication intermediate molecules with a replication fork halted at the terR site, a cell DNA extract was digested with EcoRI, electrophoresed through an agarose gel and stained with ethidium bromide. In addition to two major bands, one derived from vector DNA and the other from the ter insert fragment, two extra minor bands were detected. Following DNA-DNA hybridization and electron microscopic observation we concluded that the two minor bands corresponded to the two Y-shaped molecules, produced from the theta-shaped intermediate molecules by EcoRI digestion.

DNA Replication↗
PubMed1987

A newly discovered tRNA(1Asp) gene (aspV) of Escherichia coli K12.

We report a new tRNA(1Asp) gene near the dnaQ gene, which is located at 5 min on the Escherichia coli linkage map. We named it aspV. The sequence corresponding to the mature tRNA is identical with that of the two previously identified tRNA(1Asp) genes (aspT and aspU), but there is no homology in the sequences of their 3'- and 5'-flanking regions.

Base Sequence↗
PubMed1987

Plasma free fatty acids and protein binding of disopyramide during haemodialysis.

The binding of disopyramide (DSP) to plasma (or serum) proteins was determined using an ultrafiltration technique in three patients undergoing haemodialysis. An increase in the free fraction (FF) of DSP during dialysis occurred together with elevation of the free fatty acid (FFA) level in plasma. The effect of FFA on protein binding in vitro was examined using DSP- and FFA-spiked solutions containing human alpha 1-acid glycoprotein and serum albumin. The FF of DSP rose in proportion to increasing FFA levels, supporting the in vivo observations. The findings suggest that the free concentration of DSP should be routinely monitored, especially in haemodialysis patients.

Adult↗
PubMed1987

Synthetic partial extension peptides of P-450(SCC) and adrenodoxin precursors: effects on the import of mitochondrial enzyme precursors.

Various portions of the extension peptides of P-450(SCC) precursor were chemically synthesized. The effects of these peptides on the import of enzyme precursors into mitochondria were examined. Peptides SEP1-15 and SEP1-20, corresponding to the amino terminal portion of the extension peptides, strongly inhibited the import of P-450(SCC) precursor into mitochondria. These peptides were effective at concentrations above 30 microM, and complete inhibition was observed at 100 microM. SEP1-11, which is shorter than SEP1-15 and SEP1-20, showed very weak inhibition. SEP25-39, which corresponds to the carboxy terminal portion of the extension peptide, did not affect the import of the precursor. The import of P-450(11 beta) and adrenodoxin precursors were also inhibited by SEP1-15. Another peptide, AEP1-14, which corresponds to the amino terminal portion of the extension peptide of adrenodoxin precursor, was also synthesized. The peptide inhibited the import of both adrenodoxin and P-450(SCC) precursors into mitochondria. The import of malate dehydrogenase was also inhibited by SEP1-15 and AEP1-14. The rate of the internalization of the precursor into mitochondria was decreased by the peptides. The amount of the precursor bound to the surface of mitochondria and the processing of adrenodoxin precursor were not affected. The respiratory activities of isolated mitochondria were not influenced by SEP1-15 even at 100 microM. We conclude that the inhibitory activities of the synthetic partial extension peptides on the import of enzyme precursors into mitochondria require the presence of about fifteen amino acid residues in the amino terminal portion of the extension peptides, and the inhibition of the import by the peptides was dependent on the blockage of the internalization of the precursors into mitochondria.

Adrenodoxin↗
PubMed1987

Cloning and sequence analysis of adrenodoxin reductase cDNA from bovine adrenal cortex.

cDNA clones for bovine adrenodoxin reductase were isolated, and the primary structure of the enzyme precursor was deduced from their nucleotide sequences. The precursor consists of 492 amino acids including an extrapeptide of 32 amino acids at the amino terminus. The extrapeptide is hydrophilic [corrected] and rich in arginine. The amino terminal sequence of the precursor is homologous with that of the adrenodoxin precursor. A possible FAD- or NADPH-binding site is present near the amino terminus of the mature enzyme.

Adrenal Cortex↗
PubMed1987

Hormonal responses to insulin-induced hypoglycemia in man.

Insulin-induced hypoglycemia is a potent stress stimulating ACTH release, but the factors responsible for this ACTH secretion are not known. In this study, several ACTH-stimulating factors, such as CRH, arginine vasopressin (AVP), epinephrine (E), norepinephrine (NE), and dopamine, in addition to ACTH, cortisol, and glucose, were simultaneously measured in plasma before and 15, 30, 60, 90, and 120 min after iv administration of 0.1 U/kg BW regular insulin to seven normal subjects. Insulin administration resulted in significant rises in the mean plasma ACTH level from 4.6 +/- 1.1 (+/- SEM) to 21.6 +/- 4.8 pmol/L at 30 min (P less than 0.01) and in plasma cortisol from 330 +/- 60 to 720 +/- 50 nmol/L at 60 min (P less than 0.01). These increases were preceded by a 41.0 +/- 1.9% (P less than 0.001) fall in blood glucose levels. The mean plasma CRH level rose significantly from 1.0 +/- 0.1 to 1.2 +/- 0.1 pmol/L (P less than 0.01) at 30 min and remained elevated until 120 min. In addition, concomitant and significant rises in plasma AVP levels (basal, 1.5 +/- 0.01; peak, 4.5 +/- 1.1 pmol/L at 30 min; P less than 0.01), E (basal, less than 50; peak, 640 +/- 130 pmol/L at 30 min; P less than 0.01), and NE (basal, 0.07 +/- 0.01; peak, 0.17 +/- 0.03 nmol/L at 60 min; P less than 0.05), but not dopamine, also occurred. These results suggest that multiple ACTH-releasing factors, such as CRH, AVP, E, and NE, are involved in ACTH secretion induced by insulin-induced hypoglycemia in man.

Adrenocorticotropic Hormone↗
PubMed1987

Secundum atrial septal defect with severe pulmonary hypertension. Open lung biopsy diagnosis of operative indication.

In 14 of 15 patients ranging in age from 1 to 62 years (mean of 34) with secundum atrial septal defect (ASD) and pulmonary hypertension over 60 mm Hg peak pressure, operative indication was determined by morphometric diagnosis of open biopsy of lung specimens. In one patient, open lung biopsy was also performed during corrective surgery. Pulmonary arterial changes in the 15 patients were grouped into four classifications as follow: (1) plexogenic pulmonary arteriopathy (six patients); (2) thromboembolism in small pulmonary arteries (three patients); (3) "musculoelastosis," intimal proliferation of longitudinal smooth muscle bundles and elastic fibers (three patients); and (4) combinations of (1), (2) or (1), (3) (three patients). We conclude concerning the operative indication that group 2 patients are operable in all cases and group 1 patients with Yamaki's index of pulmonary vascular disease of 2.2 or less; group 3 patients with the absence of complete occlusion of the small pulmonary arterial lumen are operable, and patients with clear evidence of severe plexogenic pulmonary arteriopathy in group 4 are not operable. Comparative analysis of pulmonary pathology and hemodynamic performance revealed that open lung biopsy should be performed to determine operative candidacy in cases with a pulmonary vascular resistance greater than 8 unit X m2, which is considered to represent the borderline of operability.

Adult↗
PubMed1987

Long-term results of open heart repair of ventricular septal defect.

Long-term follow-up results of 321 patients who underwent open heart repair of ventricular septal defect in our institute and have lived for more than five years were analyzed using questionnaires. The follow-up period was up to 24 years with an average of 12.9 years. The questionnaire mainly concerned the patient's state of health. Beside this, IQ was measured in 52 children, ECG was analyzed in 92 patients and heart catheterization was performed on 21 patients with preoperative severe pulmonary hypertension (PH). From this survey, it was ascertained that no deaths resulted from cardiac disorders; physical activity and development were satisfactory in nearly all patients; the scholastic achievement score was within the normal range in nearly all school children; among 30 live births from 24 adult female patients, two babies with simple cardiac anomalies were found and there remained very few patients suffering from residual PH, residual shunt or conduction disturbances. IQ as tested by individual intelligence tests was within the normal range in all children. On ECG, complete right bundle branch block with left anterior hemiblock was found in 9% and complete atrioventricular block in 7%. Amelioration of PH was achieved especially in those who underwent operations in their younger years.

Adolescent↗
PubMed1987

Biochemical and hemodynamic changes in the hypertrophied dog heart subjected to chronic protein-calorie malnutrition.

Biochemical and hemodynamic changes were assessed in 13 dogs subjected to sub-coronary valvular aortic stenosis and chronic protein-calorie malnutrition (PCM). Red blood cell, hemoglobin, serum albumin, free fatty acids, blood glucose, cholinesterase and blood amino acid levels were measured. The dynamic geometry of the left ventricle (LV) was assessed with chronically implanted sonomicrometric piezoelectric crystals. Cardiac function was evaluated by mean velocity of circumferential fiber shortening (mean VcF) and the relationship between LV end-systolic pressure (LVESP) or LV wall stress (LVWst) and LV end-systolic diameter (LVESD). The following results were obtained: A decrease in body weight and increases in free fatty acids and 3-Methylhistidine were observed following long-term PCM. Mean VcF was not depressed in dogs subjected to PCM. The relationship between LVESP or LVWst and LVESD shifted downward and to the right after PCM, indicating reduced myocardial contractility. These findings suggest that the left ventricle in hypertrophied dog hearts subjected to PCM retains normal pump function, despite a low state in the myocardium.

Animals↗
PubMed1987

Presence of tumor promoters in the seed oil of Jatropha curcas L. from Thailand.

The seed oil of Jatropha curcas L. was shown to contain skin tumor promoters in a two-stage mouse carcinogenesis experiment. By using the irritant test on mouse ear to monitor activity, the "irritant fraction" was partially purified from the methanol extract of the seed oil by column chromatographies on Florisil and Sephadex LH-20. The irritant fraction obtained induced ornithine decarboxylase in mouse skin and inhibited the specific binding of 3H-12-O-tetradecanoylphorbol-13-acetate to a particulate fraction of mouse skin. After initiation with 7,12-dimethylbenz[a]anthracene (DMBA), this "irritant fraction" induced tumors in the skin of 36% of the mice tested in 30 weeks. Tumor incidences in the groups treated with DMBA alone and "irritant fraction" alone were 7% and 13% in week 30, respectively. Since the skin of Thai people comes into direct contact with this seed oil, an epidemiological study on human skin cancer in Thailand is indicated.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Synthetic analogues (indolactams) of (-)-indolactam-V are new congeners of the teleocidin class of tumor promoters.

(-)-Indolactam-V, which has the partial structure of teleocidins A and B, and has tumor-promoting activity, is a good model for use in studies on the relation between structure and tumor-promoting activity, whereas (+)-indolactam-V has no tumor-promoting activity. In this work, five racemic indolactams differing only in their alkyl group at C-12 of (-)-indolactam-V were synthesized and tested for biological and biochemical activities related to tumor promotion. The activities tested were inductions of ornithine decarboxylase in mouse skin and human promyelocytic leukemia (HL-60) cell adhesion, inhibition of specific [3H]12-O-tetradecanoyl-phorbol-13-acetate binding to a mouse particulate fraction and activation of protein kinase C in vitro. The results showed that (+/-)-indolactam-L and (+/-)-indolactam-F had almost the same activities as (+/-)-indolactam-V, suggesting that (-)-indolactam-L and (-)-indolactam-F are new tumor promoters with as high potency as (-)-indolactam-V. (+/-)-Indolactam-t-L, which has a highly lipophilic group at C-12 of (-)-indolactam-V, showed the highest activities in the above tests. (-)-Indolactam-t-L might have stronger tumor-promoting activity than (-)-indolactam-V. Furthermore, the results with (-)-indolactam-t-L indicated the possibility of designing new tumor promoters with stronger activity than teleocidin.

Animals↗
PubMed1987

Characterization and localization of Paragonimus westermani antigen stimulating antibody formation in both the infected cat and rat.

Applicability of the adult Paragonimus westermani antigen for detection of anti-immature P. westermani antibodies in experimentally infected rats, a paratenic host of this lung fluke, was examined. The serum antibodies of the cats and rats infected with P. westermani metacercariae were detected by enzyme-linked immunosorbent assay (ELISA) with the adult-fluke antigen. The ELISA titers of serum samples of the rats infected with only immature flukes were as high as those of the cats infected with adult flukes. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and the immunoblotting technique showed that a major protein band of 27,000 daltons was recognized in the sera of the infected cats and rats. Immunoperoxidase staining applied on the sectioned flukes provided evidence showing that the antigenic substance was located on the surface of the gut epithelium and in the luminal contents in both adult and immature flukes. The adult-fluke antigen containing the 27,000-dalton substance is applicable as a standard antigen for diagnosis of paragonimiasis westermani in not only definitive hosts but also in paratenic hosts.

Animals↗