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S Nishimura

Publications and source records attributed to S Nishimura.

At least 235 records · Page 13Linked to original sources
PubMed1997

High performance polymer supports for enzyme-assisted synthesis of glycoconjugates.

Efficient and practical methodology for the construction of carbohydrates, including oligosaccharide derivatives and sphingoglycolipids, was established on the basis of a water-soluble polymer supports having unique linkers that can be cleaved by specific conditions. Novel glycomonomers for the construction of polymer supports were synthesized and copolymerized with acrylamide to give three types of water-soluble glycopolymers having primer sugars through the specific linkers containing (i) p-substituted benzyl group, (ii) L-phenylalanine residue, and (iii) ceramide-mimetic L-serine derivative, respectively. These glycopolymers were employed for sugar elongation reactions with glycosyl transferases such as GlcNAc beta 1,4-galactosyl transferase, beta Gall-->3/4GlcNAc alpha-2,6-sialyl transferase, and beta Gall-->3/4GlcNAc alpha-2,3-sialyl transferase in the presence of each sugar nucleotide as glycosyl donor to afford polymers having N-acetyllactosamine, sialyl alpha-(2-->6) N-acetyllactosamine, and sialyl alpha-(2-->3) lactose residues in excellent yield. Subsequent hydrogenolysis, hydrolysis with alpha-chymotrypsin, or transglycosylation to ceramide with ceramide glycanase proceeds smoothly to give N-acetyllactosamine, a versatile sialyl alpha-(2-->6) N-acetyllactosamine derivative having a terminal amino group, and ganglioside GM3 in high yield.

Acrylic Resins↗
PubMed1997

Angiotensin converting enzyme inhibitors suppress production of tumor necrosis factor-alpha in vitro and in vivo.

It has been reported that angiotensin converting enzyme (ACE) inhibitors have beneficial effects on insulin resistance and congestive heart failure, in which elevations of serum tumor necrosis factor-alpha (TNF-alpha) level have been indicated. Therefore, in this study, we examined effect of ACE inhibitors on TNF-alpha production both in vitro and in vivo by using human blood mononuclear cells and mice, respectively. LPS (20 micrograms/ml)-induced in vitro TNF-alpha production, measured by bioassay and enzyme-linked immunosorbent assay, was significantly inhibited with captopril, delapril and cilazapril in a concentration of 10(-3) mol/l. A single, oral administration of captopril, delapril and cilazapril at more than 10-fold doses of common clinical use in man significantly inhibited LPS (2 mg/kg)-induced serum TNF-alpha activity in Balb/c mice. These results indicate that ACE inhibitors such as captopril, delapril and cilazapril have an inhibitory effect on TNF-alpha production not only in vitro as previously reported, but also in vivo, although relatively high concentrations and large doses were required in this study.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

Inhibitory effect of nicotinamide on in vitro and in vivo production of tumor necrosis factor-alpha.

Nicotinamide, a pellagra-preventive factor, has multiple functions such as inhibition of poly-ADP-ribose synthetase, inhibition of inducible nitric oxide synthase, free radical scavenging and suppression of major histocompatibility complex class II expression and ICAM-1 expression on endothelial cells. In addition to these, we have found an inhibitory effect of nicotinamide on production of tumor necrosis factor-alpha (TNF-alpha) in vitro and in vivo. Lipopolysaccharide (LPS)-induced in vitro TNF-alpha production by human peripheral blood mononuclear cells, measured by enzyme-linked immunosorbent assay (ELISA), was significantly inhibited with more than 1 x 10(-3) mol/l of nicotinamide, while interleukin-1-beta was not inhibited and interleukin-6 was slightly inhibited even with 10(-2) mol/l. Oral administration of nicotinamide with more than 62.5 mg/kg also significantly inhibited LPS-induced serum TNF-alpha production measured by ELISA and bioassay in Balb/c mice. Thus, nicotinamide has an inhibitory effect on TNF-alpha production that may be beneficial to TNF-alpha-mediated diseases.

Animals↗
PubMed1997

Effectiveness of an antioxidant in preventing restenosis after percutaneous transluminal coronary angioplasty: the Probucol Angioplasty Restenosis Trial.

OBJECTIVES: The Probucol Angioplasty Restenosis Trial was a prospective, randomized, controlled study that investigated the effectiveness of probucol therapy in reducing the rate of restenosis after percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: Antioxidants have an inhibitory effect on smooth muscle cell growth in experiments in vitro and in vivo, which suggests a possible pharmacologic effect on restenosis after PTCA. METHODS: One hundred one patients were randomly assigned to receive 1,000 mg/day of probucol or control (no lipid-lowering) therapy 4 weeks before PTCA. After 4 weeks of premedication, both groups underwent PTCA. Probucol was continued until follow-up angiography 24 weeks after PTCA. Angiographic results were analyzed at a core laboratory by quantitative coronary angiography. RESULTS: Dilation was successful in 46 of 50 patients in the probucol group and 45 of 51 in the control group. At follow-up angiography 24 weeks after angioplasty, angiographic restenosis occurred in 9 (23%) of 40 patients in the probucol group and 22 (58%) of 38 in the control group (p = 0.001). Minimal lumen diameter was 1.49 +/- 0.75 mm (mean +/- SD) in the probucol group and 1.13 +/- 0.65 mm in the control group (p = 0.02). Percent diameter stenosis at follow-up angiography in the probucol group was significantly lower than that in the control group (43.9% vs. 56.4%, p = 0.009). The late loss was 0.37 +/- 0.69 mm in the probucol group and 0.60 +/- 0.62 mm in the control group (p = 0.13). The loss/gain ratio was 0.32 +/- 0.74 in the probucol group and 0.56 +/- 0.81 in the control group (p = 0.059). Net gain was greater in the probucol group than in the control group (0.77 +/- 0.70 vs. 0.48 +/- 0.59 mm, p = 0.053). CONCLUSIONS: Probucol administered beginning 4 weeks before PTCA appears to reduce restenosis rates.

Aged↗
PubMed1997

TEL/AML1 fusion gene resulting from a cryptic t(12;21) is uncommon in adult patients with B-cell lineage ALL and CML lymphoblastic transformation.

TEL is a new member of the ETS-like family on chromosome 12 and forms fusion genes with several partners in leukemia. Among these fusion genes, the TEL/AML1 translocation resulting from t(12;21) is found in approximately one quarter of the childhood B-cell lineage acute lymphoblastic leukemia (ALL) cases and its prognosis is excellent. We examined 42 adult patients with B-cell lineage ALL and 13 adult patients with lymphoblastic transformation of chronic myeloid leukemia (CML) to detect TEL/AML1 fusion genes using the reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blotting, but no translocation was detected. These findings indicate that absence of the TEL/AML1 fusion transcript partly correlates with the poorer outcome of adult B-cell lineage ALL as compared with childhood ALL and the TEL/AML1 fusion transcript is specific for pediatric B-cell lineage ALL.

Adolescent↗
PubMed1997

The association between haematological manifestation and mtDNA deletions in Pearson syndrome.

We studied the proportion of deleted mitochondrial DNA in blood cells from patients with Pearson syndrome. Patient 1 is a 17-year-old female with Kearns-Sayre syndrome who survived Pearson syndrome. Patient 2 is a 5-year-old boy with Pearson syndrome who recovered from refractory anaemia but continues to have thrombocytopenia and neutropenia. Patient 3 is a female neonate who died with severe acidosis and pancytopenia at 14 days of age. Southern blot analysis was performed with total DNA from three patients' blood cells and two samples of bone marrow cells from one patient. In peripheral blood, patients with a higher proportion of deleted mitochondrial DNA had lower blood cell counts. In patient 2, the percentage of mutant mitochondrial DNA in bone marrow cells decreased as anaemia improved. This indicates that the proportion of deleted mitochondrial DNA in peripheral blood and in bone marrow has a tendency to correlate to the severity of haematological manifestation.

Adolescent↗
PubMed1997

Myelomonoblastic leukaemia cells carrying the PEBP2beta/MYH11 fusion gene are CD34, c-KIT+ immature cells.

To clarify the aspects affected by the PEBP2beta/MYH11 fusion gene involved in the inv(16), we analysed immunophenotypes in myelomonoblastic leukaemias. We found high expressions of CD34 and c-KIT antigens in myelomonoblastic cells from all patients carrying this fusion gene, including two with M4 and one CML blastic phase, in contrast to those with M4 without the fusion gene. These findings indicate that immunophenotyping is useful for detecting a leukaemia with the fusion gene in myelomonoblastic leukaemias and that the PEBP2beta/MYH11 gene is involved in immature cells expressing CD34 and c-KIT antigens.

Antigens, CD34↗
PubMed1997

Ca2+-induced Ca2+ release in Chinese hamster ovary (CHO) cells co-expressing dihydropyridine and ryanodine receptors.

Combined patch-clamp and Fura-2 measurements were performed on chinese hamster ovary (CHO) cells co-expressing two channel proteins involved in skeletal muscle excitation-contraction (E-C) coupling, the ryanodine receptor (RyR)-Ca2+ release channel (in the membrane of internal Ca2+ stores) and the dihydropyridine receptor (DHPR)-Ca2+ channel (in the plasma membrane). To ensure expression of functional L-type Ca+ channels, we expressed alpha2, beta, and gamma DHPR subunits and a chimeric DHPR alpha(i) subunit in which the putative cytoplasmic loop between repeats II and III is of skeletal origin and the remainder is cardiac. There was no clear indication of skeletal-type coupling between the DHPR and the RyR; depolarization failed to induce a Ca2+ transient (CaT) in the absence of extracellular Ca2+ ([Ca2+]o). However, in the presence of [Ca2+]o, depolarization evoked CaTs with a bell-shaped voltage dependence. About 30% of the cells tested exhibited two kinetic components: a fast transient increase in intracellular Ca2+ concentration ([Ca2+]i) (the first component; reaching 95% of its peak <0.6 s after depolarization) followed by a second increase in [Ca2+]i which lasted for 5-10 s (the second component). Our results suggest that the first component primarily reflected Ca2+ influx through Ca2+ channels, whereas the second component resulted from Ca2+ release through the RyR expressed in the membrane of internal Ca2+ stores. However, the onset and the rate of Ca2+ release appeared to be much slower than in native cardiac myocytes, despite a similar activation rate of Ca2+ current. These results suggest that the skeletal muscle RyR isoform supports Ca2+-induced Ca2+ release but that the distance between the DHPRs and the RyRs is, on average, much larger in the cotransfected CHO cells than in cardiac myocytes. We conclude that morphological properties of T-tubules and/or proteins other than the DHPR and the RyR are required for functional "close coupling" like that observed in skeletal or cardiac muscle. Nevertheless, some of our results imply that these two channels are potentially able to directly interact with each other.

Animals↗
PubMed1997

Intramembrane signaling mediated by hydrogen-bonding of water and carboxyl groups in bacteriorhodopsin and rhodopsin.

The light-induced mechanism for proton pumping of bacteriorhodopsin was studied by Fourier transform infrared spectroscopy of the discrete sequential intermediate states, L, M, and N. Attention is focused on L in the early microsecond time range, as a transition state in which the Schiff base forms strong H-bonding with a water molecule coordinated with Asp85. This structure leads to transfer of the Schiff base proton to Asp85 in the L-to-M process, which then triggers proton release from Glu204 to the extracellular surface. H-bonding of Arg82 and water molecules are involved in this process. Chloride can replace Asp85 in the D85T mutant, and this anion will be then transported instead of a proton. In L, structural perturbations are induced also around Asp96, through a string of H-bonding mediated by internal water molecules and peptide carbonyls in helices B and C, and Trp182 in helix F. These may cause the structural changes that occur later in the M-to-N process. Similar interactions, through internal water molecules and the peptide bonds in helices B and C, take place in bovine rhodopsin. They transduce changes across the membrane from the Schiff base to the cytoplasmic surface, where the activation of the transducin occurs.

Animals↗
PubMed1997

Transforming growth factor-beta and hepatocyte growth factor produced by gastric fibroblasts stimulate the invasiveness of scirrhous gastric cancer cells.

Scirrhous gastric carcinoma is characterized by cancer cells that infiltrate rapidly in the stroma with extensive growth of fibroblasts. In the present study, we examined the effect of gastric fibroblasts on the invasiveness of a scirrhous gastric cancer cell line, OCUM-2D, using an invasion assay. Gastric fibroblast-derived conditioned medium (CM) significantly stimulated the invasiveness of OCUM-2D cells, as did transforming growth factor-beta (TGF-beta) and hepatocyte growth factor (HGF). The stimulating activity of gastric fibroblast-derived CM was inhibited significantly by anti-TGF-beta neutralizing antibody or anti-HGF neutralizing antibody. TGF-beta and HGF were detected in the gastric fibroblast-derived CM, and TGF-beta receptor and C-met (HGF receptor) were expressed on OCUM-2D cells. Thus, TGF-beta and HGF produced by gastric fibroblasts appear to affect the invasiveness of scirrhous gastric cancer cells. TGF-beta was also detected in the conditioned medium derived from OCUM-2D cells, though HGF was not. TGF-beta appears to affect the invasiveness of OCUM-2D cells in both paracrine and autocrine fashions.

Adenocarcinoma, Scirrhous↗
PubMed1997

A case of X-linked alpha-thalassemia/mental retardation syndrome: analysis of hemoglobin by an automated glycated hemoglobin analyzer.

A 5-year-old male patient with X-linked alpha-thalassemia/mental retardation syndrome is reported. He showed multiple minor anomalies including characteristic facial abnormalities, alpha-thalassemia, severe mental retardation, and hypogonadism. Analysis of his hemoglobin by high performance liquid chromatography using an automated glycated hemoglobin analyzer revealed an abnormal peak. Identification of an abnormal peak by an automated glycated hemoglobin analyzer will aid in the diagnosis of patients with X-linked alpha-thalassemia/mental retardation syndrome.

Abnormalities, Multiple↗
PubMed1997

Transmembrane signaling mediated by water in bovine rhodopsin.

Unhydrated air-dried films of rhodopsin from bovine rod outer segment membranes do not produce its active state, metarhodopsin II. In order to reveal requirements for its formation, we studied changes in H-bonding of water, peptide carbonyl and carboxylic acid in the photochemical reactions by means of difference Fourier transform infrared spectroscopy, under both hydrated and unhydrated conditions. A water molecule near Glu113, which undergoes H-bonding change in bathorhodopsin, remained in the unhydrated film, but with a weaker H-bonding state than in the hydrated film. The other water molecules, which shfit in lumirhodopsin and metarhodopsin I as well as in bathorhodopsin of the hydrated film, were not observed in the unhydrated film. Effects of the dehydration were detected in all the C=O stretching vibrations of the peptide backbone and of Asp83 in the formation of bathorhodopsin. The C=O stretching band of Asp83 of lumirhodopsin and metarhodopsin I is intensified in the unhydrated film. We propose that structural changes at the intradiscal site in the interaction between the Schiff base and Glu113 affect water molecules, the peptide backbone, Asp83 and Glu122 in helices B and C through consecutive photochemical processes to metarhodopsin II.

Animals↗
PubMed1997

Tension pneumopericardium following tracheoplasty for congenital tracheal stenosis.

Tension pneumopericardium is a rare complication of mechanical ventilation following tracheoplasty for congenital tracheal stenosis. This case report describes fatal tension pneumopericardium in a three-month-old male infant some 24 hours following tracheoplasty for this condition. Because of persisting stenosis of the left main bronchus, ventilation pressures of PIP 23 cm H2O and PEEP 5 cm, progressing to PIP 28 cm and PEEP 7 cm were needed to maintain adequate respiratory exchange. Partial relief of the pneumopericardium was achieved by vigorous cardiac massage, but three days later the infant died of massive airway haemorrhage.

Acidosis, Respiratory↗
PubMed1997

Heart rate, blood lactate responses and ratings of perceived exertion to 1,000 punches and 1,000 kicks in collegiate karate practitioners.

The purpose of this study was: 1) to investigate the responses of heart rate (HR), blood lactate and ratings of perceived exertion (RPE) to 1,000 punches and 1,000 kicks in collegiate highly skilled (BB Group) and novice (WB Group) karate practitioners; and, 2) to compare RPE obtained from the subjects to RPE expected by their coaches. The mean values of HR, percent of maximal HR (% HRmax), percent of maximal HR reserve (% MHRR), blood lactate and RPE in 1,000 punches for the BB Group were 102.5 +/- 14.8 beats. min-1, 53.1 +/- 8.5%, 27.1 +/- 12.7%, 0.8 +/- 0.2 mmol.1-1 and 12.2 +/- 1.2 respectively, and for the WB Group were 116.1 +/- 17.9 beats. min-1, 58.1 +/- 7.7%, 35.2 +/- 13.3%, 1.2 +/- 0.6 mmol.1-1 and 12.8 +/- 1.2, respectively. Likewise, the mean values in 1,000 kicks for the BB Group were 127.4 +/- 12.4 beats. min-1, 66.0 +/- 8.0%, 47.0 +/- 12.5%, 1.3 +/- 0.4 mmol.1-1 and 14.2 +/- 1.2, respectively, and for the WB Group were 137.0 +/- 14.4 beats.min-1, 70.1 +/- 7.4%, 52.0 +/- 12.8%, 2.4 +/- 0.8 mmol. 1-1 and 16.3 +/- 1.5, respectively. These responses to 1,000 punches and 1,000 kicks were moderate, and the RPE for 1,000 punches in both BB and WB Groups and for 1,000 kicks in the BB Group were significantly lower than the RPE expected by their coaches.

Adult↗
PubMed1997

Expression of MAGE genes in colorectal carcinomas.

The human genes MAGE-1 and MAGE-3 encode tumor rejection antigens recognized on melanoma cells by cytotoxic T lymphocytes (CTL). These antigens are potentially useful as targets for specific immunotherapy. Expression of MAGE genes in some malignant tumors has been reported, but MAGE gene expression in colorectal carcinomas has not been studied adequately. Therefore, we studied MAGE-1,2,3, and 4 a/4 b expression at the mRNA level, in 40 cases of surgery for colorectal carcinoma, using the reverse transcription polymerase chain reaction (RT-PCR). MAGE-1,2,3, and 4 a/4 b genes were expressed in 3 (7.5%), 6 (15.0%), 13 (32.5%), and 5 (12.5%), respectively, of these 40 cases. A total of 19 of the 40 samples (47.5%) expressed at least one of the MAGE genes. The relationships between clinicopathologic factors and MAGE gene expression were also examined. The frequency of lymph node metastasis was significantly higher in MAGE-3-positive than in MAGE-3-negative cases (p < 0.05). All these cases classified as Duke's D expressed the MAGE-3 gene. This rate of expression was significantly higher than that for all other the Duke's classifications together (p < 0.05). Our findings suggest that MAGE-specific immunotherapy against colorectal carcinomas may be feasible.

Aged↗
PubMed1997

Genetic variation in the VP7 gene of human rotavirus serotype 3 (G3 type) isolated in China and Japan.

Sequence analysis of the VP7 gene was performed on twenty-one human isolates of serotype 3 related-rotavirus in China and Japan. The five Chinese isolates were found to be not similar to the 16 Japanese isolates and to SA11 (simian rotavirus). The Chinese isolates, especially CHW2 and CH-32, were different from the major serotype 3 human isolates. AU-1 and 02/92 which previously showed a wider spacing between RNA segments 10 and 11 by RNA polyacrylamide gel electrophoretic analysis, were more closely related to each other and could be differentiated from the other Chinese and Japanese isolates. For these reasons, serotype 3 viruses were considered to be intraserotypically more heterologous than serotype 1, 2 and 4 viruses.

Amino Acid Sequence↗
PubMed1997

Effect of the histamine H2-receptor antagonist (+/-)-(E)-1-[2-hydroxy-2-(4-hydroxyphenyl)ethyl]-3'-[2-[[[5-methylamino ) methyl-2-furyl] methyl]thio]ethyl]-2"-(methylsulfonyl)guanidine on acute gastric mucosal injury in rats and its free-radical scavenging activities.

The protective effect of T-593 ((+/-)-(E)-1-[2-hydroxy-2-(4-hydroxyphenyl)ethyl]-3'-[2-[[[5-(methylamino) methyl-2-furyl]methyl]thio]ethyl]-2"-(methylsulfonyl)guanidine, CAS 140695-21-2), a new histamine H2-receptor antagonist, was investigated in rats with acute gastric mucosal injury. An ischemic injury followed by reperfusion was produced by applying a small vascular clamp to the celiac artery for 30 min and then removing it for 60 min. T-593 significantly reduced the area of the lesion in the stomach in a dose-dependent manner, and doses of 0.3 and 3.0 mg/kg inhibited the increase of lipid peroxides in the gastric mucosa after ischemia-reperfusion. A spin-trapping method using 5,5-dimethyl-1-pyrroline-N-oxide showed that T-593 scavenged hydroxyl radicals generated by the hydrogen peroxide-ferrous iron sulfate system. T-593 also significantly inhibited the increase of lipid peroxides induced by free-radical initiators in gastric mucosal homogenates. Thus, the protective effect of T-593 against acute gastric mucosal injury induced by ischemia and followed by reperfusion may result, in part, from its antioxidant properties.

Animals↗