Search PubMed⌕ Search

Biomedical subjects

H Taniguchi

Publications and source records attributed to H Taniguchi.

At least 271 records · Page 15Linked to original sources
PubMed1996

Rifampicin resistance and mutation of the rpoB gene in Mycobacterium tuberculosis.

Using 39 clinical isolates of Mycobacterium strains with a broad range of susceptibility to rifampicin, we examined the relationship between the degree of resistance to rifampicin and mutational sites of the rpoB gene. All rifampicin-resistant strains had missense mutations. Twenty strains (95%) had a mutation in the cluster I region, which has also been reported in Escherichia coli [Jin and Gross (1988) J. Mol. Biol. 202, 45-58], and the remaining one strain had a mutation at codon 381 [Ala-->Val] in the N-terminal region, which has not been reported in E. coli. Among 18 rifampicin-susceptible strains, two had a mutation in the cluster I region and the other three strains had a mutation in the cluster III region. The mutations at codons 513 (5%), 526 (33%) or 531 (43%) in the cluster I region led to high level resistance to rifampicin (50 micrograms ml-1 < or = MIC). The mutations at the other sites, in the cluster III region (codons 679 or 687) and even in the cluster I region (codon 514, 521, or 533), showed low level (MIC = 12.5 micrograms ml-1) or no (MIC < 0.39 microgram ml-1) resistance to rifampicin. These results suggest that mutations in the rpoB gene are, mostly, but not necessarily, associated with rifampicin resistance of M. tuberculosis, and the sites of mutations on the rpoB gene will affect the level of resistance to rifampicin.

Amino Acid Sequence↗
PubMed1996

Production and crystallization of lobster muscle tropomyosin expressed in Sf9 cells.

A new form of muscle tropomyosin crystal has been obtained, by employing new strategies in protein preparation and crystallization. Non-polymerizable tropomyosin was prepared by removing 11 amino acids at the C-terminus. The truncated tropomyosin was expressed in Sf9 insect cells by use of the baculovirus-based expression system, to obtain highly homogeneous protein preparations. By routinely monitoring homogeneity by mass spectrometry, we found that the homogeneity played a key role in obtaining good crystals. The crystal quality was also dependent on isoforms; the crystals raised from a slow muscle-specific isoform diffracted to a higher resolution, compared with a fast muscle-specific counterpart. For crystallization, a high concentration of organic solvent was used as the precipitant; in the presence of 35% DMSO, tetragonal crystals were formed, which belong to space group P4(3)(1)2(1)2 with cell constants of a=b=105.6 angstrom, c=506.9 angstrom. The crystals gave rise to reflections the intensities of which were characteristically determined by the transform of alpha-helical coiled-coil. Thus in the region of 10-5.5 angstrom resolut along the c*-axis, the reflections were weak. For accurate measurement of these reflection intensities, beam-line ID2 in ESRF Grenoble was advantageous owing to the high brilliance and a low background. There the crystals diffracted to beyond 3.0 A along the c*-axis, whereas along the a*-b*-plane reflections were limited to 6.6 angstrom. Data analysis is under way on a data set from a PtCl4 derivative.

Amino Acid Sequence↗
PubMed1996

Pharmacological profile of T-0632, a novel potent and selective CCKA receptor antagonist, in vivo.

The pharmacological profile of a new CCKA receptor antagonist, T-0632 [sodium (S)-1-(2-fluorophenyl)-2,3-dihydro-3-[(3-isoquinolinylcarbonyl) amino]-6-methoxy-2-oxo-1H-indole-3-propanoate], was examined in in vivo studies and compared with those of L-364, 718 [3S(-)-N-(2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-1, 4-benzodiazepine-3-yl)-1 H-indole-2-carboxamide] and loxiglumide [D.L-4-(3,4-dichlorobenzoylamino)-5-(N-3-methoxypropyl-pentylam ino)-5- oxopentanoic acid]. In rats, intravenously administered T-0632, L-364,718 and loxiglumide dose dependently inhibited cholecystokinin octapeptide (CCK-8)-stimulated pancreatic exocrine secretion with estimated ED50 values of 0.025, 0.016 and 1.8 mg/kg, respectively. The ED50 values for intraduodenal administration of these compounds were 0.040, 0.26 and 3.0 mg/kg, respectively. In mice, orally administered T-0632 prevented caerulein-induced pancreatitis, CCK-8-induced inhibition of gastric emptying and CCK-8-induced gallbladder emptying in dose-dependent manners with ED50 values of 0.028, 0.04, and 0.12 mg/kg, respectively. The effect of T-0632 for caerulein-induced pancreatitis was 4-fold more potent than that for gallbladder emptying. In contrast, the effects of L-364,718 and loxiglumide for caerulein-induced pancreatitis were 2-4-fold weaker than those for gallbladder emptying. In dogs, T-0632 and loxiglumide maximally inhibited CCK-8-stimulated pancreatic amylase secretion at doses of 0.01 and 10 mg/kg, respectively. At these doses, the effect of T-0632 on CCK-8-induced increase in the gallbladder intraluminal pressure was weaker than that of loxiglumide. These results suggest that T-0632 has a potent antagonistic action on CCKA receptors in several animal species and the effects of T-0632 are more selective for the pancreas over the gallbladder compared with L-364,718 and loxiglumide.

Animals↗
PubMed1996

Site-specific phosphorylation of synapsin I by mitogen-activated protein kinase and Cdk5 and its effects on physiological functions.

Posttranslational modifications of synapsin I, a major phosphoprotein in synaptic terminals, were studied by mass spectrometry. In addition to a well known phosphorylation site by calmodulin-dependent protein kinase II (CaM kinase II), a hitherto unrecognized site (Ser553) was found phosphorylated in vivo. The phosphorylation site is immediately followed by a proline, suggesting that the protein is an in vivo substrate of so-called proline-directed protein kinase(s). To identify the kinase involved, three proline-directed protein kinases expressed highly in the brain, i.e. mitogen-activated protein (MAP) kinase, Cdk5-p23, and glycogen synthase kinase 3beta, were tested for the in vitro phosphorylation of synapsin I. Only MAP kinase and Cdk5-p23 phosphorylated synapsin I stoichiometrically. The phosphorylation sites were determined to be Ser551 and Ser553 with Cdk5-p23, and Ser62, Ser67, and Ser551 with MAP kinase. Upon phosphorylation with MAP kinase, synapsin I showed reduced F-actin bundling activity, while no significant effect on the interaction was observed with the protein phosphorylated with Cdk5-p23. These results raise the possibility that the so-called proline-directed protein kinases together with CaM kinase II and cAMP-dependent protein kinase play an important role in the regulation of synapsin I function.

Actins↗
PubMed1996

Pharmacological profile of T-0632, a novel potent and selective CCKA receptor antagonist, in vitro.

The pharmacological profile of a new CCKA receptor antagonist, T-0632 [sodium (S)-3-[1-(2-fluorophenyl)-2,3-dihydro-3-[(3-isoquinolinyl)-carbonyl] amino-6-methoxy-2-oxo-1-H-indole]propanoate], was examined in in vitro studies and compared with those of L-364,718 [3S(-)-N-(2,3-dihydro-1-methyl-2-oxo-5-phenyl-1H-1, 4-benzodiazepine-3-yl)-1H-indole-2-carboxamide] and loxiglumide [D,L-4-(3,4-dichlorobenzoylamino)-5-(N-3-methoxypropyl-pentylam ino)-5- oxopentanoic acid]. T-0632 inhibited the specific binding of [125I]CCK-8 to rat pancreatic CCKA receptor in a concentration-dependent and competitive manner. The Ki value of T-0632 for the CCKA receptor was estimated to be 0.24 nM, which was 23 000-fold less than the Ki value (5600 nM) for guinea pig CCKB receptor. L-364,718 and loxiglumide were 1500- and 64-fold selective for CCKA over CCKB receptor, respectively. T-0632, L-364,718 and loxiglumide inhibited CCK-8 (100 pM)-stimulated amylase release from rat pancreatic acini in a concentration-dependent manner with IC50 values of 5.0 nM, 5.0 nM and 3.0 microM, respectively. In the isolated rabbit gallbladder smooth muscle, T-0632 and loxiglumide competitively inhibited CCK-8-induced contraction with pA2 values of 8.5 and 7.0, respectively. However, L-364,718 showed an apparent non-competitive antagonism. The IC50 values of T-0632, L-364,718 and loxiglumide for CCK-8 (30 nM)-induced contraction were 31 nM, 4.9 nM and 1300 nM, respectively. The inhibitory effects of T-0632 and loxiglumide in gallbladder smooth muscle were readily reversible, but L-364,718 showed a long-lasting inhibition. These results suggest that T-0632 is a potent, reversible and more selective CCKA receptor antagonist compared with L-364,718 and loxiglumide.

Amylases↗
PubMed1996

Early gastric lymphoma: a clinicopathologic study of ten patients, literature review, and comparison with early gastric adenocarcinoma.

BACKGROUND: Improved diagnostic techniques have increased early detection of gastric lymphoma as well as the early detection of adenocarcinoma. However, clinicopathologic features of early gastric lymphoma are presently undefined. METHODS: Clinicopathologic features of 10 patients with early gastric lymphoma were compared with the same features of 180 patients with early gastric adenocarcinoma. In addition, 46 articles were reviewed to evaluate clinicopathologic differences. RESULTS: Early gastric lymphoma was found in 29.2% of the patients who underwent surgery for gastric lymphoma. Early gastric lymphoma was associated with lymph node involvement in 29.9% of the patients, superficial spreading tumors in 48.6%, and multifocal lesions in 40%. These rates are greater than those in patients with adenocarcinomas (P < 0.05%). The survival rate was identical in both groups. Early gastric lymphoma may develop into large, multifocal tumors, accompanied by lymph node involvement. CONCLUSIONS: Surgical treatment with a wide resection of the stomach and extensive lymph node dissection is necessary for early gastric lymphomas.

Adenocarcinoma↗
PubMed1996

Angiogenesis inhibitor TNP-470 prevents implanted liver metastases after partial hepatectomy in an experimental model without impairing wound healing.

The ability of the angiogenesis inhibitor TNP-470 to prevent liver metastasis after partial hepatectomy, and whether TNP-470 impairs liver regeneration or skin wound healing, was evaluated. Following the injection of VX2 carcinoma cells into the portal vein of rabbits, half of the animals underwent resection of the middle hepatic lobe (hepatectomized group) and half did not (non-hepatectomized group). TNP-470 (50 mg) was infused continuously into the portal vein in both groups for 7 days, while controls received only water. The hepatectomized TNP-470-treated group had significantly fewer tumours (mean(s.e.m.) 23.3(12.3)) than the hepatectomized control group (123.7(24.4)). There was no significant difference in the 5-bromo-2'-deoxyuridine labelling index of regenerated hepatocytes between the TNP-470-treated and control groups. Wound healing in TNP-470-treated animals was not impaired. Intraportal infusion of TNP-470 prevents the recurrence of liver metastasis after partial hepatectomy without impairing healing or liver regeneration.

Animals↗
PubMed1996

Successful application of an omental pedicle flap in delayed repair of a perforated esophageal diverticulum: report of a case.

Mediastinitis resulting from a perforated esophageal diverticulum is a potentially fatal complication and the surgical treatment of persistent esophagomediastinal fistula may be difficult. In this report, we describe the successful application of an omental pedicle flap in the delayed repair of a perforated esophageal diverticulum. A 53-year-old man presented with chest and back pain and a diagnosis of perforated esophageal diverticulum was subsequently confirmed. After receiving conservative treatment, he was referred to our department and underwent surgical repair 6 months following the onset of the perforation. Through a right thoracotomy, the mucosal layer of the esophagus around the diverticulum was sutured, and an omental pedicle flap was used to cover the suture line and obliterate the fistulous tract. His postoperative course was uneventful and the suture line healed well. The successful treatment of this patient reinforces our belief that wider application of the omental pedicle flap can be expected in the field of thoracic surgery.

Diverticulum, Esophageal↗
PubMed1996

Cloning and expression of a novel gene for a protein with leucine-rich repeats in the developing mouse nervous system.

In a variety of organisms from yeast to humans, members of the leucine-rich repeat (LRR) family, in which one repeal consists of 24 amino acids and leucine residues appear regularly, have been shown to be involved in protein-protein interactions. In Drosophila, members of this family have significant functions in neural development. It is thus possible that similar molecules play a crucial role in the morphogenesis of the mammalian nervous system. Using a human brain cDNA fragment encoding an LRR as a probe, we have isolated a mouse brain cDNA which encodes a new LRR protein, NLRR-3 protein. The isolated cDNA is 3350 bp long including one open reading frame encoding a protein of 707 amino acids, the deduced amino acid sequence of which has a signal peptide and a transmembrane region. The NLRR-3 protein also contains an RGD sequence and 11 LRRs with amino- and carboxy-terminal LRR-flanking regions which are conserved among adhesive proteins and signal-transducing receptors in this family. Northern-blot analysis revealed strong expression of an approx. 4.2 kb NLRR-3 mRNA in the brain from E17 to P7 and weak expression in adults. There in situ hybridization analysis demonstrated that NLRR-3 mRNA was expressed in the brain, in which stronger expression was localized in the ventricular zone and anlage of thalamus, spinal cord, and dorsal root ganglion in E11-17 cerebellum, and cerebral cortex in adults. The molecular structure in addition to the transient and localized expression suggests that the NLRR-3 protein plays a role in the development and maintenance of the nervous system by protein-protein interactions.

Amino Acid Sequence↗
PubMed1996

Myocardial and vascular effects of efonidipine in vitro as compared with nifedipine, verapamil and diltiazem.

1. Effects of efonidipine on isolated myocardial and aortic preparations were compared with those of nifedipine, verapamil and diltiazem. 2. All drugs produced concentration-dependent negative chronotropic effects on isolated guinea-pig atrial preparations. The potency order was efonidipine > or = nifedipine > diltiazem > or = verapamil, EC30 values being 3.08 x 10(-8)M, 3.48 x 10(-8)M, 1.27 x 10(-7)M and 1.47 x 10(-7)M, respectively. 3. Nifedipine, verapamil and diltiazem produced concentration-dependent negative inotropic effects on isolated guinea-pig left atrial preparations. The potency order was nifedipine > verapamil > diltiazem, EC30 values being 4.94 x 10(-8)M, 1.49 x 10(-7)M and 8.03 x 10(-7)M, respectively. Efonidipine, even at 1 microM produced no inotropic effect: 10 microM efonidipine decreased the contractile force by about 20%. 4. All drugs concentration-dependently attenuated the KCl-induced contraction of isolated rat aortic ring preparation. The potency order was nifedipine > efonidipine > verapamil > diltiazem, EC30 values being 2.98 x 10(-9)M, 1.24 x 10(-8)M, 3.96 x 10(-8)M and 2.13 x 10(-7)M, respectively. 5. Thus, efonidipine was demonstrated to be a potent vasodilator with negative chronotropic but minimal negative inotropic activity, which may be of benefit in the treatment of cardiovascular disorders.

Animals↗
PubMed1996

Clinicopathological characteristics of gastric cancer in the elderly.

The clinicopathological features of 380 elderly patients 70 years of age or older with gastric cancer were reviewed retrospectively from hospital records between 1969 and 1993. They were then compared with 1134 middle-aged patients between 40 and 69 years. The elderly constituted 18.4% of all gastric cancer patients 20 years ago but now comprise 24.4% of all patients in the most recent decade, despite the overall decrease in the rate of gastric cancer. The distinguishing histological features of gastric cancer in the elderly were an intestinal type of cancer, expansive tumour growth and synchronous multiplicity of the lesions. Elderly patients had a similar rate of tumour extension but had poorer survival as compared with the middle-aged patients. Post-operative death within 30 days after surgery was also higher in the elderly than in the middle-aged patients.

Adolescent↗
PubMed1996

Presence of hematopoietic stem cells in the adult liver.

Recently, cases have been reported in which a mixed chimeric state of blood cells is established after liver transplantation. Because the established chimerism may have aided in the induction of donor-specific tolerance, the mechanism responsible for this chimerism is of clinical importance. To establish this, we examined cells in adult mouse liver and identified the presence of c-kit+ Sca-1+ Lin(lo/-) cells. These cells were capable of forming in vivo as well as in vitro colonies. Furthermore, the cells could reconstitute bone marrow of lethally irradiated recipient mice for at least 12 months. These data obtained from the mouse study strongly suggest that hematopoietic stem cells residing in the donor liver are responsible for mixed chimerism and maintenance of tolerance after liver transplantation.

Animals↗
PubMed1996

Significance of IL-1beta and IL-1 receptor antagonist (IL-1Ra) in bronchoalveolar lavage fluid (BALF) in patients with diffuse panbronchiolitis (DPB).

We evaluated the effect of erythromycin therapy on pulmonary function tests and the airway inflammatory response of patients with DPB. The number of neutrophils in BALF obtained from DPB patients was significantly higher than that of healthy volunteers. Treatment with erythromycin (600 mg/day for 12.9+/-9.5 months (mean +/- s.d.)) significantly reduced the total number of cells and neutrophils in the airway, and significantly improved pulmonary function tests. The levels of IL-1beta and IL-8 were significantly higher in DPB compared with healthy volunteers (P<0.05, P<0.05, respectively). IL-1Ra in patients is considered to have a weak inhibitory activity for IL-1beta, with approximately five-fold concentration of IL-1beta compared with that in healthy volunteers (approx. nine-fold concentration of IL-1beta). Erythromycin therapy significantly reduced these cytokines to levels comparable to those of healthy volunteers, and produced a trend toward reduction in the level of IL-1Ra in BALF. The level of IL-1beta correlated significantly with the concentration of neutrophils in BALF (r=0.72, P<0.01), as well as with the level of IL-1Ra (r=0.688, P<0.05) and IL-8 (r=0.653, P<0.05). A nearly significant or significant correlation was observed between the concentration of neutrophils and levels of IL-1Ra or IL-8 in BALF (r=0.526, P=0.053 or r=0.776, P<0.01, respectively). There was also a significant relationship between FEV(1) and the concentration of neutrophils in BALF (r=0.524, P<0.05). Our results suggest that the relative amounts of IL-1beta and IL-1Ra or IL-8 may contribute, at least in part, to the neutrophil-mediated chronic airway inflammation in patients with chronic airway disease, and long-term erythromycin therapy may down-regulate the vigorous cycle between the cytokine network and neutrophil accumulation, with resultant reduction of neutrophil-mediated inflammatory response.

Adult↗
PubMed1996

Quantitative measurement of human tissue hepatic blood volume by C15O inhalation with positron-emission tomography.

In order to estimate the tissue liver function, tissue hepatic blood volume was measured quantitatively and non-invasively using C15O inhalation in conjunction with positron-emission tomography. Fifty-eight patients with normal liver function, 14 patients with chronic hepatitis, 28 patients with hepatic cirrhosis, and 4 patients with obstructive jaundice were studied by positron-emission tomography scan after the single breath inhalation of 20 mCi of high specific activity 15O-labeled carbon monoxide. The mean tissue hepatic blood volume was significantly greater in patients with normal livers than in patients with chronic hepatitis or hepatic cirrhosis (mean: 20.5, 18.2, and 16.1 ml per 100 cm3, respectively, p = 8.6 x 10(-8)). Tissue hepatic blood volume (tHBV) correlated with the reaction of the mesenchymal system and protein synthesis, because there was a potent correlation between tHBV and hepatic fibrosis. In normal livers, we were able to demonstrate significant differences in tissue hepatic blood volume among liver segments.

Blood Volume↗
PubMed1996

Bilateral giant myelolipoma in the adrenal of a cotton-top tamarin (Saguinus oedipus).

A rare case of bilateral adrenal myelolipomas in a female cotton-top tamarin is reported. Large bilateral masses in the adrenal glands were composed of mature adipose cells containing varying amounts of hematopoietic cells of the myeloid, erythroid, and megakaryocytic series. The gross and histologic features of this case closely resemble human "giant" adrenal myelolipomas.

Adrenal Cortex↗