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T Yoshimura

Publications and source records attributed to T Yoshimura.

At least 145 records · Page 8Linked to original sources
PubMed1999

Most gastric cancer occurs on the distal side of the endoscopic atrophic border.

BACKGROUND: The endoscopic atrophic border indicates the extent of atrophic gastritis. The aims of this study were to examine the relation of intestinal and diffuse types of gastric cancer to the atrophic border and to study the pathologic condition of the atrophic border. METHODS: In 83 patients with gastric cancer the extent of atrophic gastritis was assessed macroscopically. In 46 patients gastric biopsy specimens were also taken, to compare the histologic features of gastritis proximal and distal to the atrophic border. RESULTS: Eighty-five per cent of gastric cancers (including 93% of intestinal type) occurred on the distal side of the atrophic border. Early diffuse gastric cancer arose closer to the atrophic border than intestinal-type cancer and was more likely to be sited proximal to it. Histologically, the grade of polymorphonuclear cell infiltration (inflammatory activity) and Helicobacter pylori density were significantly greater on the proximal side (P < 0.05), whereas the grades of glandular atrophy and intestinal metaplasia were significantly greater distally (P < 0.001). CONCLUSIONS: The atrophic border delineates the area of atrophic gastritis and intestinal metaplasia, and it is within the distal part of the stomach that gastric cancer occurs most frequently. Endoscopists should observe the distal side particularly carefully to identify early gastric cancer. The relationship of the two histologic types of cancer to areas of intestinal metaplasia and 'active' inflammation may have implications for the pathogenesis of cancer and, if so, for the potential protective effect of H. pylori eradication.

Endoscopy, Gastrointestinal↗
PubMed1999

Correlation of the intrinsic clearance of donepezil (Aricept) between in vivo and in vitro studies in rat, dog and human.

1. Donepezil hydrochloride (Aricept) is used for the treatment of Alzheimer's disease. Here the correlation of the intrinsic clearance (Cl(int)) of donepezil between the in vivo and in vitro states was studied in rat, dog and human. 2. In an experiment with 14C-donepezil and human microsomes the routes of metabolism were identified as N-dealkylation and O-demethylation, and no unknown metabolites were detected. 3. The Cl(int) of donepezil in the male rat, female rat, dog and human liver microsomes were 33.7, 13.4, 37.0 and 6.35 microl/min/mg microsomal protein respectively, and sex difference in rat and interspecies difference in the estimated Cl(int) were found. 4. After a single intravenous administration to the male rat, female rat and dog, total plasma clearance (ClP(total)) was 78.6, 29.5 and 88.3 ml/min/kg respectively, and a sex difference was observed in rat. 5. After a single oral administration to the male rat, dog and healthy volunteer, ClP(total) was 140, 105 and 2.35 ml/min/kg respectively, and remarkable differences were observed between animals and man. 6. The contribution of renal clearance to blood clearance (Cl(r)) was low in all species. The predicted in vitro hepatic clearance (Cl(h-pre)) was in the rank order: male rat (15.91 ml/min/kg) > dog (7.96) > female rat (7.67) > human (1.04). Although Cl(h-pre) was underestimated, Cl(h-pre) was significantly correlated with that of ClB(total) in the different animal species and in man, indicating that the in vitro-in vivo ranking order was conserved.

Administration, Oral↗
PubMed1999

In vivo distribution and behavior of paramagnetic dinitrosyl dithiolato iron complex in the abdomen of mouse.

It has been shown that a dinitrosyl dithiolato iron complex is formed under physiological conditions and that it functions as an NO transporter. In the present study, a diglutathionyl dinitrosyl iron complex [DNIC-(GS)2] was injected into mice and its abdominal distribution and behavior were examined by using electron paramagnetic resonance (EPR) spectroscopy. The X-band EPR signal intensity of the blood, liver, kidney, and spleen decreased with time but signals from the liver and kidney were readily detectable even 24h after the injection. The time courses of signal intensity were quite similar when the agent was administered via intravenous and subcutaneous injection routes, suggesting that DNIC-(GS)2 can penetrate readily and rapidly through the membranes. Real-time detection of DNIC-(GS)2 in the upper abdomen of the living mice was performed by employing an in vivo EPR spectroscopy. These results suggest that DNIC-(GS)2, an endogenous NO carrier, has an excellent membrane permeability and has a relatively high affinity for the liver and kidney.

Abdomen↗
PubMed1999

Role of tyrosine 265 of alanine racemase from Bacillus stearothermophilus.

Tyrosine 265 (Y265) of Bacillus stearothermophilus is believed to serve as a catalytic base specific to the L-enantiomer of a substrate amino acid by removing (or returning) an alpha-hydrogen from (or to) the isomer on the basis of the X-ray structure of the enzyme [Stamper, C.G., Morollo, A.A., and Ringe, D. (1998) Biochemistry 37, 10438-10443]. We found that the Y265-->Ala mutant (Y265A) enzyme is virtually inactive as a catalyst for alanine racemization. We examined the role of Y265 further with beta-chloroalanine as a substrate with the expectation that the Y265A mutant only catalyzes the alpha,beta-elimination of the D-enantiomer of beta-chloroalanine. However, L-beta-chloroalanine also served as a substrate; this enantiomer was rather better as a substrate than its antipode. Moreover, the mutant enzyme was as equally active as the wild-type enzyme in the elimination reaction. These findings indicate that Y265 is essential for alanine racemization but not for beta-chloroalanine elimination.

Alanine Racemase↗
PubMed1999

Tyrosine 265 of alanine racemase serves as a base abstracting alpha-hydrogen from L-alanine: the counterpart residue to lysine 39 specific to D-alanine.

Alanine racemase of Bacillus stearothermophilus has been proposed to catalyze alanine racemization by means of two catalytic bases: lysine 39 (K39) abstracting specifically the alpha-hydrogen of D-alanine and tyrosine 265 (Y265) playing the corresponding role for the antipode L-alanine. The role of K39 as indicated has already been verified [Watanabe, A., Kurokawa, Y., Yoshimura, T., Kurihara, T., Soda, K., and Esaki, N. (1999) J. Biol. Chem. 274, 4189-4194]. We here present evidence for the functioning of Y265 as the base catalyst specific to L-alanine. The Y265-->Ala mutant enzyme (Y265A), like Y265S and Y265F, was a poor catalyst for alanine racemization. However, Y265A and Y265S catalyzed transamination with D-alanine much more rapidly than the wild-type enzyme, and the bound coenzyme, pyridoxal 5'-phosphate (PLP), was converted to pyridoxamine 5'-phosphate (PMP). The rate of transamination catalyzed by Y265F was about 9% of that by the wild-type enzyme. However, Y265A, Y265S, and Y265F were similar in that L-alanine was inert as a substrate in transamination. The apo-form of the wild-type enzyme catalyzes the abstraction of tritium non-specifically from both (4'S)- and (4'R)-[4'-(3)H]PMP in the presence of pyruvate. In contrast, apo-Y265A abstracts tritium virtually from only the R-isomer. This indicates that the side-chain of Y265 abstracts the alpha-hydrogen of L-alanine and transfers it supra-facially to the pro-S position at C-4' of PMP. Y265 is the counterpart residue to K39 that transfers the alpha-hydrogen of D-alanine to the pro-R position of PMP.

Alanine↗
PubMed1999

Isolation of novel GRO genes and a phylogenetic analysis of the CXC chemokine subfamily in mammals.

Approximately 15 different alpha, or CXC, chemokines have thus far been isolated from 11 species of mammals. Among the best studied chemokines are the 12 human proteins that are encoded by 11 paralogous genes. In order to better understand the evolution and function of this group of genes, we isolated and characterized six novel GRO and GRO-related cDNA sequences from the cow (Bos taurus), the sheep (Ovis aries), the rabbit (Oryctolagus cuniculus), and the guinea pig (Cavia porcellus). The amino acid sequence of the diverged guinea pig GRO or KC gene is only 50%-60% similar to presumed orthologs from other species, while the sheep and cow GRO proteins are 90%-99% similar to each other. The presence of multiple GRO genes in the cow, the rabbit, and the sheep is consistent with what has been observed for humans. Phylogenetic analyses of amino acid sequences from 44 proteins indicate that genes orthologous to many of the 11 known from humans exist in other species. One such gene, interleukin 8, or IL8, has been isolated from nine species, including the rodent guinea pig; however, this gene is absent in the rat and the mouse, indicating a unique gene loss event in the rat/mouse (muroid rodent) lineage. The KC (or MIP2) gene of rodents appears to be orthologous to the GRO gene found in other taxonomic orders. Combined evidence from different sources suggests that IP10 and MIG share sister taxon relationships on the evolutionary tree, while the remaining paralogous genes represent independent lineages, with limited evidence for kinship between them. This observation indicates that these genes originated nearly contemporaneously via a series of gene duplication events. Relative-rate tests for synonymous and nonsynonymous nucleotide substitutions in the KC and IL8 genes did not detect rate heterogeneity; however, there are several notable features regarding the IL8 genes. For example, the IL8 proteins from two Old World monkeys are as similar to one another as they are to the IL8 protein from humans, and all observed nucleotide differences between the IL8 genes of the two monkeys cause amino acid changes; in other words, there are no synonymous differences between them.

Amino Acid Sequence↗
PubMed1999

Lambert-Eaton myasthenic syndrome associated with idiopathic thrombocytopenic purpura and diffuse panbronchiolitis: long-term remission after a course of intravenous immunoglobulin combined with low-dose prednisolone.

We report a case of Lambert-Eaton myasthenic syndrome (LEMS) associated with idiopathic thrombocytopenic purpura (ITP) and diffuse panbronchiolitis (DPB). An extensive search for malignancy yielded negative results. Interestingly, ITP and DPB developed simultaneously when the patient suffered from myasthenic symptoms. This is the first report in the Japanese or English literature of an association of LEMS, ITP, and DPB. The use of cholinesterase blocker alone did not improve the myasthenic symptoms, and the symptoms and signs relapsed with the tapering of prednisolone (PSL) dosage. However, after administration of immunoglobulin (IVIG) (0.4 g/kg/day x 5 days), low-dose PSL (20 mg/day) alleviated the LEMS and ITP, and the diseases have remained in remission for 8 months without additional IVIG. We suspect that there is a synergistic relationship between IVIG and PSL.

Anti-Inflammatory Agents↗
PubMed1999

Direct evidence of in vivo nitric oxide production and inducible nitric oxide synthase mRNA expression in the brain of living rat during experimental meningitis.

To detect endogenous nitric oxide (NO) produced in a rat bacterial meningitis model, the authors applied an electron paramagnetic resonance (EPR) NO-trapping technique. Iron complex with N,N-diethyldithiocarbamate were used as a trapping agent. Experimental meningitis was induced by a mixture of lipopolysaccharide and interferon-gamma. Sequential changes of NO formation under meningitis were observed in rat brain tissue by using X-band (9 GHz) EPR spectroscopy, and endogenous NO was detected in the head of a living rat with a 700-MHz EPR system. Inducible NO synthase mRNA expression in the brain tissues also was proven by using a reverse transcriptase-polymerase chain reaction technique.

Animals↗
PubMed1999

Cold-active serine alkaline protease from the psychrotrophic bacterium Shewanella strain ac10: gene cloning and enzyme purification and characterization.

The gene encoding serine alkaline protease (SapSh) of the psychrotrophic bacterium Shewanella strain Ac10 was cloned in Escherichia coli. The amino acid sequence deduced from the 2,442-bp nucleotide sequence revealed that the protein was 814 amino acids long and had an estimated molecular weight of 85,113. SapSh exhibited sequence similarities with members of the subtilisin family of proteases, and there was a high level of conservation in the regions around a putative catalytic triad consisting of Asp-30, His-65, and Ser-369. The amino acid sequence contained the following regions which were assigned on the basis of homology to previously described sequences: a signal peptide (26 residues), a propeptide (117 residues), and an extension up to the C terminus (about 250 residues). Another feature of SapSh is the fact that the space between His-65 and Ser-369 is approximately 150 residues longer than the corresponding spaces in other proteases belonging to the subtilisin family. SapSh was purified to homogeneity from the culture supernatant of E. coli recombinant cells by affinity chromatography with a bacitracin-Sepharose column. The recombinant SapSh (rSapSh) was found to have a molecular weight of about 44,000 and to be highly active in the alkaline region (optimum pH, around 9.0) when azocasein and synthetic peptides were used as substrates. rSapSh was characterized by its high levels of activity at low temperatures; it was five times more active than subtilisin Carlsberg at temperatures ranging from 5 to 15 degreesC. The activation energy for hydrolysis of azocasein by rSapSh was much lower than the activation energy for hydrolysis of azocasein by the subtilisin. However, rSapSh was far less stable than the subtilisin.

Amino Acid Sequence↗
PubMed1999

Molecular cloning of the guinea pig GRO gene and its rapid expression in the tissues of lipopolysaccharide-injected guinea pigs.

BACKGROUND: CXC chemokines, IL-8 and GRO, play a role in the recruitment of neutrophils in the human. The functional orthologues in the rat and mouse are CINC/KC and MIP-2. The lack of IL-8 made these animals less useful to study the role of IL-8 and GRO. METHODS: Guinea pig (gp) cDNA libraries were screened for GRO and IL-1beta. A gp genomic library was screened with a gpGRO cDNA probe. Expression of gpIL-8, gpGRO, gpTNFalpha, and gpIL-1beta was investigated by Northern analysis and/or by in situ hybridization. RESULTS: Two gpGRO cDNAs, a 3.0-kb gpGRO genomic DNA, and a gpIL-1beta cDNA were cloned. gpGRO and gpIL-8 mRNA were detected in different tissues including lungs 1 h after intraperitoneal injection of lipopolysaccharide (LPS) into guinea pigs. gpGRO, gpIL-8, gpTNFalpha, and gpIL-1beta expression peaked at 3 h in the lungs. Both gpGRO and gpIL-8 mRNA were detected in the cells in alveolar spaces and bronchial epithelial cells. However, gpGRO mRNA, but not gpIL-8, was also expressed in endothelial cells and vascular smooth muscle cells. CONCLUSIONS: gpGRO and gpIL-8 mRNA rapidly accumulated in the lungs of guinea pigs after LPS injection. Expression of gpIL-8 and gpGRO mRNA appeared to be independent from TNFalpha- or IL-1beta-stimulation in this model. A high level expression of gpGRO in vascular cells suggest an important role of GRO in the sequestration of neutrophils and multi-organ injuries induced by LPS. The guinea pig will provide an excellent model to study the roles of IL-8 and GRO, important inflammatory mediators in the human.

Amino Acid Sequence↗
PubMed1999

Anti-inflammatory actions of interleukin-13: suppression of tumor necrosis factor-alpha and antigen-induced leukocyte accumulation in the guinea pig lung.

The Th2 cytokine interleukin (IL)-13 is believed to play an important role in the development of allergy, although it has also been ascribed anti-inflammatory roles in several experimental models. In this study, we have examined the effects of human recombinant IL-13 on eosinophilic lung inflammation in the guinea pig. IL-13 (1 to 100 ng, given by intratracheal instillation) did not elicit airway eosinophil recruitment. A pronounced accumulation of eosinophils, as well as monocyte/macrophages, was elicited by intratracheal instillation of guinea pig tumor necrosis factor alpha (gpTNF-alpha). Intratracheal administration of IL-13 (1 to 100 ng) given immediately prior to exposure to gpTNF-alpha resulted in a dose-related suppression of eosinophil and monocyte/macrophage accumulation in the airways, as assessed by bronchoalveolar lavage (BAL) and eosinophil peroxidase activity in whole-lung homogenates. IL-13 treatment also reduced BAL fluid (BALF) leukocyte accumulation induced by subsequent aerosol antigen challenge of sensitized guinea pigs. Antigen challenge also resulted in elevated levels of immunoreactive eotaxin and eosinophil-stimulating activity in BALF, although only the latter was reduced significantly by IL-13 instillation prior to challenge. In contrast to the suppressive effects of IL-13, instillation of human recombinant IL-4 (100 ng) alone elicited an increase in BALF monocyte/macrophage numbers, and IL-4 was unable to inhibit gpTNF-alpha-induced leukocyte accumulation. Hence, IL-13 (but not human IL-4) exhibits an anti-inflammatory action in the airways of gpTNF-alpha- or antigen-challenged guinea pigs, by mechanisms that may involve the decreased generation of eosinophil-stimulating activity in the airways.

Animals↗
PubMed1999

Relationship between the clinical efficacy of pentoxifylline treatment and elevation of serum T helper type 2 cytokine levels in patients with human T-lymphotropic virus type I-associated myelopathy.

OBJECT: Previously, we reported the efficacy of pentoxifylline (PTX) treatment in human T-lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM). Here, we clarify the relationship between the clinical efficacy of PTX treatment and elevation of T helper type 2 (Th2) cytokine levels in HAM patients. PATIENTS AND METHODS: PTX (300 mg) was administered daily by the oral route to 12 HAM patients for 4 weeks. We assessed the relationship between the changes in neurological status (motor disability scores, the degree of spasticity on neurological examination, and the time required to walk 10 m) and the changes in serum and cerebrospinal fluid (CSF) levels of interferon-gamma (IFN-gamma) as a Th1 cytokine and interleukin-4 and -10 (IL-4 and -10) as Th2 cytokines measured by an EASIA (enzyme-amplified sensitivity immunoassay) kit. RESULTS: PTX treatment induced incremental increases in the levels of IL-4 and IL-10 in both sera and CSF of 6 HAM patients. Clinical improvement was associated with this elevation in IL-4 and IL-10. PTX treatment also induced a decrease in IFN-gamma levels in the sera of 6 HAM patients, but this was not correlated with clinical improvement. CONCLUSION: These results suggest that the correction of the immunological imbalance in Th1 to Th2 cytokine responses, with upregulation of IL-4 and IL-10, may account for the clinical improvement in HAM patients treated with PTX.

Administration, Oral↗
PubMed1999

[A case of superficial siderosis of the central nervous system--findings of the neuro-otological tests and evoked potentials].

We report a 57-year-old woman with superficial siderosis of the central nervous system. On physical examination, sensorineural hearing impairment, cerebellar ataxia, pyramidal tract signs, dysarthria, and neurogenic bladder were seen. Brain and spinal cord MRI (T2 and proton weighted images) revealed cerebellar atrophy and marginal hypointensity of the Sylvian fissure and brain stem, cerebellum and spinal cord. We diagnosed this patient as superficial siderosis because of the clinical course and specific findings on MRI. We consider this case idiopathic superficial siderosis because the source of the bleeding was unknown. Neuro-otological tests and BAEP disclosed retrocochlear deafness. Her central motor conduction time on MEP was delayed. We discussed the pathogenic mechanism of these conditions, and we concluded that we must take notice of myelinopathy in superficial siderosis and that MEP was useful for detecting them.

Audiometry, Evoked Response↗
PubMed1999

[Rapidly progressive irradiated cervical cancer that metastasized to the liver during therapy for idiopathic thrombocytopenic purpura].

A 37-year-old woman was given a diagnosis of cervical cancer in August 1994. Because of severe thrombocytopenia, she was given radiation therapy at 50 Gy with great effectiveness. The thrombocytopenia was diagnosed as idiopathic thrombocytopenic purpura. Because the patient refused to undergo a splenectomy operation, she was treated with prednisolone, gamma-globulin, and danazol with no effect. In January 1995 she began receiving azathioprine and her platelet count gradually increased. In March, she complained of severe left abdominal pain but abdominal computed tomography (CT) scans showed no abnormal findings. Nonetheless, the patient's lumbago persisted and her liver dysfunction was progressive. Abdominal CT scans performed on April 18 disclosed multiple liver tumors. The patient died on April 28. Autopsy revealed that the cervical cancer was the primary origin of the liver tumors. We concluded that extra precautions should be taken when administering immunosuppressive therapy to patients with a history of malignant diseases.

Adult↗
PubMed1999

Involvement of growth-related protein in lipopolysaccharide-induced rabbit arthritis: cooperation between growth-related protein and IL-8, and interrelated regulation among TNFalpha, IL-1, IL-1 receptor antagonist, IL-8, and growth-related protein.

We investigated the functional role of a CXC chemokine, growth-related protein (GRO), in the recruitment of neutrophils in lipopolysaccharide (LPS)-induced rabbit arthritis. The amounts of GRO in the synovial fluids (SF) reached the first peak (major) at 2 hours and the second peak (minor) at 9 hours after injection of LPS into the knee joints. Administration of anti-GRO mouse monoclonal antibody inhibited 54% of the peak leukocyte accumulation at 9 hours (neutrophils greater than 95%), which was similar to the inhibition by anti-IL-8 IgG (48%). Co-administration of these inhibitors increased the inhibition up to 70% at 9 hours and also inhibited 65% of the initial phase of leukocyte infiltration at 2 hours (neutrophils greater than 99%), which was not affected by a single administration of each inhibitor. The amounts of GRO in SF at 2 hours were not altered by either anti-TNFalpha mAb or anti-IL-8 IgG, but reduced by rabbit recombinant IL-1 receptor antagonist (rrlL-1Ra) by 39%. The inhibition by rrlL-1 Ra was augmented further to 59% with coadministered anti-TNFalpha mAb. In contrast, the amounts of GRO at 9 hours were reduced by rrlL-1Ra by 67%. There was no additional reduction in the amounts of GRO at 9 hours by either combination of rrlL-1Ra with anti-TNFalpha mAb or anti-IL-8 IgG. Administration of anti-GRO mAb did not alter TNFalpha or IL-8 contents in SF at their peak (2 hours), but reduced the amounts of IL-1beta at 6 hours and IL-1Ra at 9 hours by 42% and 49%, respectively. These results provide evidence for the following: (a) GRO as well as IL-8 are important mediators involved in the recruitment of neutrophils both in the early and the late phase of LPS-induced arthritis, (b) IL-1 produced in the early phase stimulates GRO production, (c) GRO plays a role in the later induction of IL-1beta and IL-1Ra, and (d) induction of GRO is not regulated by IL-8.

Animals↗
PubMed1999

[Influential factors in elevation of serum creatine phosphokinase for the patients with Kanemi Yusho].

We studied the etiology of the elevation of serum creatin phosphokinase (CK) using the data from routine medical checkup of Kanemi Yusho patients during 1995 and 1997. We also studied the serum CK and blood urea nitrogen (BUN) in rats given the polychlolinated biphenyls as well as controls, and conducted optical microscopic observation of muscle tissue in rats given the polychlolinated biphenyls and control. The patients with elevation of serum creatine phosphokinase also showed the elevation of BUN and polychlolinated biphenyls in their serum. These are thought to be triggers of the elevation of CK in the serum. However, animal experiments failed to yield the same results as human. The rats given polycholorinated biphenyls showed atrophy of muscle fibers. Accordingly, we were unable to clarify the etiology of CK elevation in humans and muscle atrophy in rats.

Animals↗
PubMed1999

[Myasthenia gravis with electrophysiological features of Lambert-Eaton myasthenic syndrome: usefulness of serum autoantibodies assay and neuromuscular junction biopsy].

A 60-year-old man with a 40-year history of seronegative ocular myasthenia gravis (MG) developed generalized weakness cumulating crisis over 2 years. On admission, ophthalmoplegia, severe ptosis and marked generalized weakness were observed without autonomic symptoms and signs. The deep tendon reflexes were decreased, but were normalized after repeated muscle contractions. EMG of the abductor digiti minimi muscle showed low amplitude in compound muscle action potentials (0.6 mV), waxing phenomenon (292%) with 20 Hz repetitive nerve stimulation (RNS), waning phenomenon (34%) in 3 Hz RNS, and posttetanic facilitation (393%). Stimulated single fiber EMG showed reduced jitter with higher stimulation rates. Serum anti-P/Q-type voltage-gated calcium channel antibodies were negative with no evidence of malignancy. Sensitive assay of acetylcholine receptor antibody in serum revealed a positive titer, while conventional assay was negative. A muscle biopsy was performed and immune complex deposition was demonstrated at the endplate. A nearly complete clinical remission and normalization of electrophysiological features followed immunoadsorption and prednisolone therapy. A sensitive immunoassay of acetylcholine receptor antibodies and immunolocalization of complement at the endplate are useful diagnostic tools in cases presenting with features of myasthenia gravis and Lambert-Eaton myasthenic syndrome.

Autoantibodies↗