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T Fukui

Publications and source records attributed to T Fukui.

At least 181 records · Page 10Linked to original sources
PubMed1997

Identification of multiple regulatory elements of human L-histidine decarboxylase gene.

Previously, we reported the structure of human L-histidine decarboxylase gene. To identify the regions that regulate the tissue-specific expression of HDC, we constructed a fusion DNA with the 5'-flanking region from -1003 to +99 of the HDC gene and chloramphenicol acetyltransferase (CAT) gene, which was then transfected into human basophilic leukemia KU-812-F cells or human epithelial carcinoma HeLa cells. The 1102 bp DNA fragment stimulated the CAT activity in KU-812-F cells, but not in HeLa cells. CAT analysis with a series of 5'-deletion constructs of the HDC-CAT gene revealed the existence of two positive and one negative regulatory elements at -855 to -841 and -532 to -497 and -829 to -821, respectively. Sequence analysis showed a nuclear factor c-Myb binding motif, TAACTG, at position -520. Gel mobility shift analysis showed that the nuclear extract of KU-812-F cells, but not that of HeLa cells, contains a factor which can bind to this motif. These results suggest that the 5'-flanking region of the HDC gene contains multiple regulatory elements for HDC gene expression and that at least one element, including a c-Myb binding motif, is responsible for the tissue-specific expression of HDC.

Binding Sites↗
PubMed1997

Biochemical and molecular characterization of the polyhydroxybutyrate depolymerase of Comamonas acidovorans YM1609, isolated from freshwater.

Comamonas acidovorans YM1609 secreted a polyhydroxybutyrate (PHB) depolymerase into the culture supernatant when it was cultivated on poly(3-hydroxybutyrate) [P(3HB)] or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] as the sole carbon source. The PHB depolymerase was purified from culture supernatant of C. acidovorans by two chromatographic methods, and its molecular mass was determined as 45,000 Da by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The enzyme was stable at temperatures below 37 degrees C and at pH values of 6 to 10, and its activity was inhibited by diisopropyl fluorophosphonate. The liquid chromatography analysis of water-soluble products revealed that the primary product of enzymatic hydrolysis of P(3HB) was a dimer of 3-hydroxybutyric acid. Kinetics of enzymatic hydrolysis of P(3HB) film were studied. In addition, a gene encoding the PHB depolymerase was cloned from the C. acidovorans genomic library. The nucleotide sequence of this gene was found to encode a protein of 494 amino acids (M(r), 51,018 Da). Furthermore, by analysis of the N-terminal amino acid sequence of the purified enzyme, the molecular mass of the mature enzyme was calculated to be 48,628 Da. Analysis of the deduced amino acid sequence suggested a domain structure of the protein containing a catalytic domain, fibronectin type III module as linker, and a putative substrate-binding domain. Electron microscopic visualization of the mixture of P(3HB) single crystals and a fusion protein of putative substrate-binding domain with glutathione S-transferase demonstrated that the fusion protein adsorbed strongly and homogeneously to the surfaces of P(3HB) single crystals.

3-Hydroxybutyric Acid↗
PubMed1997

Cloning and analysis of the poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) biosynthesis genes of Aeromonas caviae.

A 5.0-kbp EcoRV-EcoRI restriction fragment was cloned and analyzed from genomic DNA of Aeromonas caviae, a bacterium producing a copolyester of (R)-3-hydroxybutyrate (3HB) and (R)-3-hydroxyhexanoate (3HHx) [P(3HB-co-3HHx)] from alkanoic acids or oils. The nucleotide sequence of this region showed a 1,782-bp poly (3-hydroxyalkanoate) (PHA) synthase gene (phaC(Ac) [i.e., the phaC gene from A. caviae]) together with four open reading frames (ORF1, -3, -4, and -5) and one putative promoter region. The cloned fragments could not only complement PHA-negative mutants of Alcaligenes eutrophus and Pseudomonas putida, but also confer the ability to synthesize P(3HB-co-3HHx) from octanoate or hexanoate on the mutants' hosts. Furthermore, coexpression of ORF1 and ORF3 genes with phaC(Ac) in the A. eutrophus mutant resulted in a decrease in the polyester content of the cells. Escherichia coli expressing ORF3 showed (R)-enoyl-coenzyme A (CoA) hydratase activity, suggesting that (R)-3-hydroxyacyl-CoA monomer units are supplied via the (R)-specific hydration of enoyl-CoA in A. caviae. The transconjugant of the A. eutrophus mutant expressing only phaC(Ac) effectively accumulated P(3HB-co-3HHx) up to 96 wt% of the cellular dry weight from octanoate in one-step cultivation.

Acyltransferases↗
PubMed1997

p22phox mRNA expression and NADPH oxidase activity are increased in aortas from hypertensive rats.

Recent studies suggest that superoxide production by the NADPH/NADH oxidase may be involved in smooth muscle cell growth and the pathogenesis of hypertension. We previously showed that angiotensin II (Ang II) activates a p22phoxbased NADPH/NADH oxidase in cultured rat vascular smooth muscle cells and in animals made hypertensive by infusion of Ang II. To investigate the mechanism responsible for this increased oxidase activity, we examined p22phox mRNA expression in rats made hypertensive by implanting an osmotic minipump that delivered Ang II (0.7 mg/kg per day). Blood pressure began to increase 3 days after the start of Ang II infusion and remained elevated for up to 14 days. Expression of p22phox mRNA in aorta was also increased after 3 days and reached a maximum increase of 338 +/- 41% by 5 days after pump implantation compared with the value after sham operation. This increase in mRNA expression was accompanied by an increase in the content of the corresponding cytochrome (twofold) and NADPH oxidase activity (179 +/- 11% of that in sham-operated rats 5 days after pump implantation). Treatment with the antihypertensive agents losartan (25 mg/kg per day) or hydralazine (15 mg/kg per day) inhibited this upregulation of mRNA levels and activity. Furthermore, infusion of recombinant heparin-binding superoxide dismutase decreased both blood pressure and p22phox mRNA expression. In situ hybridization of aortic tissue showed that p22phox mRNA was expressed in medial smooth muscle as well as in the adventitia. These findings suggest that Ang II-induced hypertension activates the NADPH/NADH oxidase system by upregulating mRNA levels of one or several components of this oxidase system, including the p22phox, and that the NADPH/NADH oxidase system is associated with the pathology of hypertension in vivo.

Angiotensin II↗
PubMed1997

Vascular thrombin receptor regulation in hypertensive rats.

Thrombin has been implicated as an important mediator of vascular lesion formation in atherosclerosis and restenosis. To investigate a potential role for thrombin signaling in the vascular response to hypertension, we have studied thrombin receptor (TR) expression and regulation in hypertensive rats. Aortic TR mRNA was upregulated by angiotensin II (Ang II)-induced hypertension (10.7 +/- 2.5 times control, P < .02), which correlated with a 4-fold increase in thrombin-induced constriction in isolated endothelium-denuded aortic rings. The AT1 receptor antagonist losartan normalized blood pressure and TR mRNA. Conversely, lowering blood pressure to the same degree with hydralazine did not abolish the upregulation of TR mRNA expression. When low-renin low-Ang II hypertension was induced in Dahl salt-sensitive rats, there was no detectable increase in the expression of aortic thrombin receptor mRNA. Finally, treatment with a chimeric heparin-binding form of the recombinant human Cu/Zn superoxide dismutase caused complete inhibition of TR mRNA upregulation, suggesting that an increased rate of superoxide anion production is an important signaling mechanism. Thus, increased TR expression via a redox-sensitive mechanism in the aortic smooth muscle of rats treated with Ang II represents a novel in vivo mechanism through which the hypertensive effects of Ang II are mediated.

Angiotensin II↗
PubMed1997

A reductive acidolysis final deprotection strategy in solid phase peptide synthesis based on safety-catch protection.

A reductive acidolysis final deprotection strategy in solid phase peptide synthesis was developed using a new safety-catch type of semi-permanent protecting groups and new linkers which were derived from 4-methylsulfinylbenzyl protection. This new strategy was based on a two-dimensional protection scheme employing acid-labile temporary and acid-stable but reductive acidolysis-cleavable semi-permanent protecting groups. By using this strategy, we successfully synthesized four model peptides, of which two contained C-terminal amide.

Amino Acid Sequence↗
PubMed1997

The relationship between abdominal pain regions and specific diseases: an epidemiologic approach to clinical practice.

In order to evaluate the relationship between the patient-identified regions of abdominal pain and the disease diagnosis, a prospective study was conducted at General Medicine Outpatient Clinic, Saga Medical School Hospital. Four hundred eighty-nine outpatients complaining of abdominal pain at the first visit were classified into 10 groups according to the pain region complained of, i.e., whole abdominal, epigastric, right subcostal, left subcostal, right flank, left flank, periumbilical, right-lower, mid-lower, and left-lower, the clinic physicians and authors in joint-participation assigned the groups through studying the medical records. Comparisons were made in order to calculate sensitivity, specificity, and the positive and negative likelihood ratios between the pain regions and disease diagnoses. In general, the sensitivity of history-taking and physical examination is low, but specificity is, high in relation to epigastric pain and gastroduodenal diseases, right subcostal pain and hepatobiliary diseases, and mid lower pain and gynecological diseases (above 0.5). Comparative analysis between the pain regions complained of by the patient in the initial clinic visit and the medical diagnoses yielded clinically useful information as to the efficacy of medical history-taking and physical examination in the identification of abdominal diseases.

Abdominal Pain↗
PubMed1997

Sleep characteristics of Japanese working men who score alexithymic on the Toronto Alexithymia Scale.

This study examined the relationship of sleep characteristics including insomnia with scores on alexithymia in a sample of 171 Japanese working men. Levels of nonrestorative sleep and daytime sleepiness reported on a sleep questionnaire were significantly associated with scores on Depression and Confusion on the Profile of Mood States for Japanese men who had a high mean score on the Toronto Alexithymia Scale.

Adaptation, Psychological↗
PubMed1997

[Decision analysis and clinical laboratory test in general internal medicine].

OVERVIEW: We demonstrated the quantitative approach to evaluating laboratory test in a patient with hypercalcemia. CASE DESCRIPTION: 43 year-old-woman was referred to our department because of sustained hypercalcemia without subjective symptoms in the past 5 years. Physical examination showed no abnormality with laboratory tests unremarkable except for hypercalcemia (10.8 mg/dl). DIFFERENTIAL DIAGNOSIS AND PRE-TEST PROBABILITY SETTING: Based on history and physical examination, we hypothesized two possible cases of hypercalcemia; primary parathyroidism (PHP) malignant disease (MD). The pre-test probability of PHP was set at 1/3, and that of MD at 2/3. CALCULATION AND ASSESSMENT: The post-test probability using the likelihood ratio of "albumin > 4.0 g/dl", 5.1 was increased to 0.72. However, it was not considered above the test-treatment threshold. We then measured Intact PTH which has a likelihood ratio 14. Intact PTH was increased yielding the post-test probability of 0.97. We considered that this value exceeded test-treatment threshold. The patient was referred to a surgical department. CONCLUSIONS: In daily practice, we, internists have to make clinical decisions quantitatively based on test results. To make a rational and quantitative approach to diagnostic tests clinical routine, it is mandatory to determine sensitivity and specificity of all laboratory tests used in our country.

Adult↗
PubMed1997

[Surgically treated unruptured sinus of Valsalva aneurysm: a case report].

A 73-year-old man was admitted because of progressive dyspnea. Echocardiography revealed a markedly dilated right sinus of Valsalva and severe aortic regurgitation. Coaptation loss of the aortic valve leaflets was thought to be the cause of regurgitation and congestive heart failure, a rare complication of the unruptured sinus of Valsalva aneurysm. Surgical treatment should be considered to prevent life-threatening heart failure and rupture of the aneurysm even in patients without overt heart failure.

Aged↗
PubMed1997

Assessment of plaque rupture by intravascular ultrasound.

To investigate the mechanism of plaque rupture, we carried out morphologic and quantitative assessments of ruptured plaque with a 30-MHz intravascular ultrasound catheter before coronary intervention. Plaque rupture, defined as an echolucent intraplaque area communicating with arterial lumen, was noted in all of 22 patients with coronary artery disease examined in the study. The plaque was eccentric in 16 patients (73%) and in 10 of these 16 patients there was a tear at the margin of the plaque (63%). Calcification was noted in only 6 patients (22%). Plaque area ranged from 8.7 to 44.1 mm2. The ruptured area ranged widely, from 1.0 to 14.0 mm2, and the percent ruptured area also ranged widely, from 3.9% to 50.9%. Fibrous cap was recognized in 20 patients. The thickness of the fibrous cap ranged from 0.1 to 0.6 mm (mean, 0.36 mm) and thinning of the fibrous cap was noted in 16 patients (80%). From these results, we conclude that intravascular ultrasound can provide detailed observations of plaque rupture consistent with pathologic studies. Accordingly, it is a suitable method for evaluation of plaque rupture in vivo. Plaque weakness, due to the presence of atheromatous core, thin fibrous cap, and no calcification, seems to be the major determinant of plaque rupture. In addition, the great variation in cap thickness and ruptured area suggests the role of other triggers, such as mechanical and hemodynamic stress, in plaque rupture.

Coronary Artery Disease↗
PubMed1997

Tunicamycin in combination with retinoic acid synergistically inhibits cell growth while decreasing palmitoylation and enhancing retinoylation of proteins in the human breast cancer cell line MCF-7.

All-trans-Retinoic acid (RA) induces differentiation and inhibits growth of many tumor types. Whereas the RA nuclear receptors mediate genomic effects of RA, there also are many nongenomic effects that do not have defined mechanisms. Some nongenomic effects of RA may involve retinoylation (RA acylation), a posttranslational modification of proteins occurring in many eukaryotic cell lines including the human breast cancer cell line MCF-7. To gain further knowledge of the role(s) of retinoylation, we studied the effects of tunicamycin (TM), an inhibitor of both protein N-glycosylation and palmitoylation, on growth and retinoylation in MCF-7 cells. We found that RA or TM alone inhibited growth of MCF-7 cells. Combinations of RA and TM inhibited growth synergistically. TM increased retinoylation and decreased palmitoylation. These results suggest that increased retinoylation and decreased glycosylation and palmitoylation may play a role in the synergistic inhibition of cell growth by combinations of TM and RA in MCF-7 cells. Furthermore, our results suggest that combinations of TM and RA may have clinical utility.

Acylation↗
PubMed1996

Affinity labeling of Escherichia coli histidyl-tRNA synthetase with reactive ATP analogues. Identification of labeled amino acid residues by matrix assisted laser desorption-ionization mass spectrometry.

Recent affinity labeling studies have revealed that dimeric histidyl-tRNA synthetase from Escherichia coli displayed half-of-the-sites reactivity toward labeling with pyridoxal 5'-phosphate [Kalogerakos, T., Hountondji, C., Berne, P. F., Dutka, S. & Blanquet, S. (1994) Biochimie (Paris) 76, 33-44]. In the present report, affinity labeling studies were conducted by using other ATP analogues such as pyridoxal 5'-diphospho-5'-adenosine (pyridoxal-ppAdo), pyridoxal 5'-triphospho-5'-adenosine (pyridoxal-pppAdo), pyridoxal 5'-diphosphate (pyridoxal-P2) and 5'-p-fluorosulfonylbenzoyladenosine (FSO2BzAdo). The histidine-dependent isotopic [32P]PP/ATP exchange activity of His-tRNA synthetase was rapidly and completely lost upon incubation with either pyridoxal-ppAdo, pyridoxal-pppAdo or pyridoxal-P2, followed by reduction with sodium borohydride. Complete inactivation of His-tRNA synthetase corresponded to the incorporation of 2.8 mol of either pyridoxal-ppAdo or pyridoxal-P2/mol dimeric synthetase. Incubation of His-tRNA synthetase with FSO2BzAdo also resulted in a complete inactivation of the synthetase. However, contrasting with the pyridoxal derivatives, the plot of the residual enzymatic activity against the amount of covalently bound FSO2BzAdo appeared biphasic. In the early stages of inactivation, the relationship between the amount of residual activity and FSO2BzAdo incorporation was linear and extrapolated to a stoichiometry of 1.1 mol reagent/mol His-tRNA synthetase, suggesting that the labeling of one subunit was sufficient to inactivate one dimeric His-tRNA synthetase molecule. At longer incubation periods, additional reagent incorporation occurred and culminated at 2.5 mol label/mol His-tRNA synthetase. Excess of MgATP protected the enzyme against inactivation by either studied reagent. The labeled amino acid residues were identified by matrix-assisted-laser-desorption-ionization mass spectrometry, by measuring the peptide mass increase caused by the reagents. An identical set of four lysyl residues (Lys2, Lys118, Lys369 and Lys370 of His-tRNA synthetase) was found attached to pyridoxal-ppAdo or pyridoxal-P2. In addition, pyridoxal-ppAdo labeled the alpha-amino group of the N-terminal alanine. In a His-tRNA synthetase sample having incorporated 2.5 mol FSO2BzAdo/mol), the labeled amino acid residues were Lys118, Lys196, Tyr262 (or Tyr263), Lys369 and Lys377. Whatever the used reagent, Lys118 appeared to be the predominantly labeled residue, Lys118 belongs to fragment 112-124 (RHERPQK-GRYRQF) corresponding to motif 2 of class 2 aminoacyl-tRNA synthetases. The other modified lysyl residues (lysines 369, 370 and 377) are close to the catalytic motif 3, in the C-terminal region of the synthetase. Tyr262 and Tyr263 belong to a fragment 256-263 (LVRGLDYY) highly conserved among all known His-tRNA synthetase primary structures. Examination of the recently solved structure of crystalline E. coli His-tRNA synthetase [Amez, J. G., Harris, D. C., Mitschler, A., Rees, B., Francklyn, C. S. & Moras, D. (1995) EMBO J. 14, 4143-4155] shows that, with the exception of lysines 369, 370 and 377, the location of which may account for peculiar accessibility and reactivity, all the amino acid residues identified in this study map near the enzyme nucleotide-binding site, at the N-terminal catalytic domain of the synthetase.

Adenosine Triphosphate↗
PubMed1996

p22phox is a critical component of the superoxide-generating NADH/NADPH oxidase system and regulates angiotensin II-induced hypertrophy in vascular smooth muscle cells.

Superoxide anion formation is vital to the microbicidal activity of phagocytes. Recently, however, there is accumulating evidence that it is also involved in cell growth in vascular smooth muscle cells (VSMCs). We have shown that the hypertrophic agent angiotensin II stimulates superoxide production by activating the membrane-bound NADH/NADPH oxidase and that inhibition of this oxidase attenuates vascular hypertrophy. However, the molecular identity of this oxidase in VSMCs is unknown. We have recently cloned the cytochrome b558 alpha-subunit, p22(phox) (one of the key electron transfer elements of the NADPH oxidase in phagocytes), from a rat VSMC cDNA library, but its role in VSMC oxidase activity remains unclarified. Here we report that the complete inhibition of p22(phox) mRNA expression by stable transfection of antisense p22(phox) cDNA into VSMCs results in a decrease in cytochrome b content, which is accompanied by a significant inhibition of angiotensin II-stimulated NADH/NADPH-dependent superoxide production, subsequent hydrogen peroxide production, and [3H]leucine incorporation. We provide the first evidence that p22(phox) is a critical component of superoxide-generating vascular NADH/NADPH oxidase and suggest a central role for this oxidase system in vascular hypertrophy.

Angiotensin II↗
PubMed1996

A dual computed tomography linear accelerator unit for stereotactic radiation therapy: a new approach without cranially fixated stereotactic frames.

PURPOSE: To perform stereotactic radiation therapy (SRT) without cranially fixated stereotactic frames, we developed a dual computed tomography (CT) linear accelerator (linac) treatment unit. METHODS AND MATERIALS: This unit is composed of a linac, CT, and motorized table. The linac and CT are set up at opposite ends of the table, which is suitable for both machines. The gantry axis of the linac is coaxial with that of the CT scanner. Thus, the center of the target detected with the CT can be matched easily with the gantry axis of the linac by rotating the table. Positioning is confirmed with the CT for each treatment session. Positioning and treatment errors with this unit were examined by phantom studies. Between August and December 1994, 8 patients with 11 lesions of primary or metastatic brain tumors received SRT with this unit. All lesions were treated with 24 Gy in three fractions to 30 Gy in 10 fractions to the 80% isodose line, with or without conventional external beam radiation therapy. RESULTS: Phantom studies revealed that treatment errors with this unit were within 1 mm after careful positioning. The position was easily maintained using two tiny metallic balls as vertical and horizontal marks. Motion of patients was negligible using a conventional heat-flexible head mold and dental impression. The overall time for a multiple noncoplanar arcs treatment for a single isocenter was less than 1 h on the initial treatment day and usually less than 20 min on subsequent days. Treatment was outpatient-based and well tolerated with no acute toxicities. Satisfactory responses have been documented. CONCLUSION: Using this treatment unit, multiple fractionated SRT is performed easily and precisely without cranially fixated stereotactic frames.

Brain Neoplasms↗