Search PubMed⌕ Search

Biomedical subjects

S Ishikawa

Publications and source records attributed to S Ishikawa.

At least 37 records · Page 2Linked to original sources
PubMed2004

Functional expression of high-affinity receptor for immunoglobulin E on mast cells precedes that of tryptase during differentiation from human bone marrow-derived CD34 progenitors cultured in the presence of stem cell factor and interleukin-6.

BACKGROUND: CD34(+) progenitor cells develop into tryptase(+), CD117(+) mast cells when cultured in the presence of recombinant human stem cell factor (rhSCF). However, spontaneous IgE receptor (FcepsilonRI) expression during human mast cell development is not well examined. OBJECTIVE: Here, the expression and function of FcepsilonRI in and on human bone marrow-derived mast cells (HBMMCs) during development were investigated. METHODS AND RESULTS: At 4 weeks of culture, predominant cells expressed high-affinity IgE receptor alpha chain (FcepsilonRIalpha) on the cell surface determined by flow cytometry, but CD117 was less expressed. Immunocytochemistry with antitryptase mAb and anti-FcepsilonRIalpha mAb revealed intracellular and surface expression of FcepsilonRIalpha at 2 weeks of culture, but tryptase was less expressed. FcepsilonRIalpha mRNA transcript preceded that of tryptase mRNA at 2 weeks of culture determined by real-time RT-PCR, and FcepsilonRIalpha, FcepsilonRIbeta, FcepsilonRIgamma, and tryptase mRNA increased along with differentiation. FcepsilonRIalpha cross-link on HBMMC and 4-week-old mast cells/mast cell precursors induced the release of IL-5 and granulocyte macrophage-colony stimulating factor, which was enhanced by rhSCF. CONCLUSION: These data indicated that HBMMC constitutively and spontaneously expressed functional FcepsilonRI subunits at the early stage of differentiation, probably because of the differences in the ability and functional property of progenitors.

Antigens, CD34↗
PubMed2004

Detection of tryptase-, chymase+ cells in human CD34 bone marrow progenitors.

BACKGROUND: Mast cells (MCs) arise from haematopoietic stem cells. We have recently reported that CD34(+) progenitors derived from human bone marrow (BM) develop into tryptase+, chymase+ MCs when cultured in the presence of recombinant human stem cell factor (rhSCF) and recombinant human IL-6 (rhIL-6). In an experiment for the expression of chymase during differentiation, chymase+ cells were detected in human BM, but tryptase+ cells were not found. OBJECTIVE: The purpose of this study was to show the appearance of chymase+ cells in CD34(+) cells with an origin different from MC differentiation. METHODS: CD34(+) cells from human BM were sorted with anti-CD117 monoclonal antibody (mAb), and cytospins of CD34(+), CD34(+)CD117(+), or CD34(+)CD117(-) were prepared. These cells were cultured with rhSCF+rhIL-6 for 12 weeks. Some of the cells were subjected to either histological stain with Wright-Giemsa or immunocytochemistry with anti-chymase mAb. Real-time RT-PCR was also performed to compare the transcriptional level of chymase from each cell preparation. RESULTS: Chymase was expressed in CD34(+) cells as well as human MCs by immunocytochemistry. Substantial CD34(+)CD117(-) cells, but not CD34(+)CD117(+) cells, were stained immunocytochemically with anti-chymase mAb. For 1 week culture with rhSCF+rhIL-6, no cells expressed chymase in any preparation. Real-time RT-PCR revealed positivity for chymase mRNA in CD34(+) cells, but it reduced at 1 week of culture, and increased as cells developed into MCs. Chymase mRNA in CD34(+)CD117(+) cells was negligible compared with that in CD34(+)CD117(-). Tryptase mRNA was below the detectable level in CD34(+) cells, and increased along with MC differentiation. After 12 weeks of culture, CD34(+)CD117(+) developed predominantly into MCs, whereas CD34(+)CD117(-) developed into monocytes/macrophages. CONCLUSION: Our findings suggested that chymase is present not only in MCs but also in CD34(+)CD117(-) BM progenitors, but that its origin is different from the MC lineage.

Antigens, CD34↗
PubMed2004

Recombinant fibrinogen, gamma275Arg-->Cys, exhibits formation of disulfide bond with cysteine and severely impaired D:D interactions.

BACKGROUND AND OBJECTIVES: Analysis of dysfibrinogens has provided useful information aiding our understanding of molecular defects in fibrin polymerization. We have already reported impaired fibrin polymerization in a variant fibrinogen (gammaArg275Cys), the Cys being located in the D:D interface. Since this substitution occurred in a heterozygous individual, interpretation of the functional analysis was complicated. We tried to resolve this complication by synthesizing a recombinant variant fibrinogen. METHODS: A variant gamma-chain expression plasmid was transfected into Chinese hamster ovary cells expressing normal human fibrinogen Aalpha- and Bbeta-chains. The recombinant variant fibrinogen (gamma275C) was purified using an immunoaffinity column, and we compared its structure and functions with those of normal recombinant fibrinogen (gamma275R) and plasma variant fibrinogen. RESULTS: Mass analyses showed the existence of disulfide-linked Cys in both patient and recombinant variant fibrinogens. Functional analyses indicated that both fibrin polymerization and gamma-gamma dimer formation were markedly impaired in the variant fibrinogen. The impairments were much more pronounced in gamma275C than in plasma variant fibrinogen. In addition, scanning electron microscopic observation of fibrin clots made from gamma275C revealed less dense fibrin fiber bundles and larger fiber diameter than in those made from gamma275R, and also the existence of many aberrant fibrin fibers with tapered ends. CONCLUSIONS: These results indicate that gammaArg275 has an important residue affecting the structure and function of the gamma-chain C-terminal domain. However, the variant D:D interface can interact with that of the normal fibrinogen existing in a heterozygous patient with dysfibrinogenemia.

Amino Acid Substitution↗
PubMed2004

Nicorandil improves diabetes and rat islet beta-cell damage induced by streptozotocin in vivo and in vitro.

OBJECTIVE: N-(2-hydroxyethyl)-nicotinamide nitrate (nicorandil) is a unique anti-anginal agent, reported to act as both an ATP-sensitive K(+) channel opener (PCO) and a nitric oxide donor. It also has an anti-oxidant action. We examined the effects of nicorandil on streptozotocin (STZ)-induced islet beta-cell damage both in vivo and in vitro. DESIGN AND METHODS: STZ-induced diabetic Brown Norway rats (STZ-DM) were fed with nicorandil-containing chow from day 2 (STZ-DM-N48), 3 (STZ-DM-N72), and 4 (STZ-DM-N96) to day 30. Body weight, blood glucose, and plasma insulin were measured every week. For the in vitro assay, neonatal rat islet-rich cultures were performed and cells were treated with nicorandil from 1 h before to 2 h after exposure to STZ for 30 min. Insulin secretion from islet cells was assayed after an additional 24 h of culture. We also observed the effect of nicorandil on the generation of reactive oxygen species (ROS) from rat inslinoma cells (RINm5F). RESULTS: Body weight loss and blood glucose levels of STZ-DM-N48 rats were significantly lower than those of STZ-DM rats. Immunohistochemical staining of insulin showed preservation of insulin-secreting islet beta-cells in STZ-DM-N48 rats. Nicorandil also dose-dependently recovered the insulin release from neonatal rat islet cells treated with STZ in in vitro experiments. Nicorandil did not act as a PCO on neonatal rat islet beta-cells or RINm5F cells, and did not show an inhibitory effect on poly(ADP-ribose) polymerase-1. However, the drug inhibited the production of ROS stimulated by high glucose (22.0 mmol/l) in RINm5F cells. CONCLUSIONS: These results suggested that nicorandil improves diabetes and rat islet beta-cell damage induced by STZ in vivo and in vitro. It protects islet beta-cells, at least partly, via a radical scavenging effect.

Animals↗
PubMed2004

An angiogenesis inhibitor TNP-470 (AGM-1470) suppresses vascular smooth muscle cell proliferation in experimental rat aortotomy models.

AIM: Vascular intimal hyperplasia is an important clinical concern in vascular diseases, such as anastomotic stricture as a possible complication of cardiovascular surgery. We recently suggested that a rat aortotomy model could be substituted for a vascular anastomotic stricture around a suture line. TNP-470 is known as an angiogenesis inhibitor and has demonstrated abilities to inhibit DNA synthesis of smooth muscle cells (SMCs) and SMCs proliferation. The aim of this study was to investigate the effect of TNP-470 on SMC proliferation using rat aortotomy models. METHODS: Longitudinal aortotomy was performed in the abdominal aorta of rats. Rats received a subcutaneous injection of materials (TNP-470, 20 mg/kg) or vehicle 3 times a week (n=10 in each group). The aorta was harvested 2 weeks after aortotomy. Serial sections from tissues were stained with hematoxylin and eosin, and the ratio of intimal to medial cross-sectional areas (I/M ratio) was determined. Values are expressed as the mean +/- the standard deviation. Results. Thickening of the intimal layer 2 weeks following aortotomy was observed in the control group however, intimal thickening was inhibited in the TNP-treated group. The I/M ratio was significantly (p = 0.0376) lower in the TNP-treated group than in the control group (8.3 +/- 4.8 vs 15.6 +/- 9.6%). Conclusion. TNP-470 significantly suppressed intimal thickening in experimental rat aortotomy models. TNP-470 might inhibit the development of anastomotic stricture after cardiovascular surgery.

Angiogenesis Inhibitors↗
PubMed2003

Essential Bacillus subtilis genes.

To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among approximately 4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were predicted to be essential. The vast majority of essential genes were categorized in relatively few domains of cell metabolism, with about half involved in information processing, one-fifth involved in the synthesis of cell envelope and the determination of cell shape and division, and one-tenth related to cell energetics. Only 4% of essential genes encode unknown functions. Most essential genes are present throughout a wide range of Bacteria, and almost 70% can also be found in Archaea and Eucarya. However, essential genes related to cell envelope, shape, division, and respiration tend to be lost from bacteria with small genomes. Unexpectedly, most genes involved in the Embden-Meyerhof-Parnas pathway are essential. Identification of unknown and unexpected essential genes opens research avenues to better understanding of processes that sustain bacterial life.

Bacillus subtilis↗
PubMed2003

Evaluation of a low-temperature steam and formaldehyde sterilizer.

We evaluated a low-temperature steam and formaldehyde (LTSF) sterilizer based on the draft European Standard prEN 14180. Microbiological tests were conducted on small and full loads using process challenge devices in five programs (P1-P5). With small loads all tests showed no growth of Bacillus stearothermophilus (ATCC7953) spores. However, positive cultures were observed with full-load tests using P5 (sterilization temperature, 50 degrees C). Our data indicated that the load influenced the efficacy of the LTSF sterilizer. Desorption tests were conducted to determine residual formaldehyde in indicator strips. The mean concentrations of formaldehyde in P1-P5 were 31.9, 56.3, 54.9, 82.2 and 180.6 microg, respectively, which are below the limits allowed by the draft Standard. Our results indicate that the LTSF sterilizer is useful for sterilization because of its excellent efficacy, short handling time, and safety.

Disinfectants↗
PubMed2003

Mutagenicity and cross-linking activity of chloroalkylnitrosamines, possible new antitumor lead compounds.

The mutagenicity of chlorinated alpha-acetoxy nitrosamines was assayed using nine bacterial strains with various DNA repair abilities and the mechanism of their reaction with DNA was evaluated. Three alpha-acetoxy nitrosamines without a chloro group were used to investigate the effect of the chloro group on mutagenicity. Three nitrosamines having chloroethyl, chloropropyl and chlorobutyl groups were directly mutagenic in all tester strains used in this study, which showed that they damaged DNA in intact bacteria. Compared with Salmonella typhimurium TA1535, mutagenic activity was enhanced in ogt gene-deficient strains (YG7108 and YG7104), suggesting that an O(6)-alkylguanine adduct causes the mutation. The chlorinated nitrosamines showed stronger mutagenicity than non-chlorinated nitrosamines, indicating that alkylating activity was strengthened by the presence of a chloro group. The nitrosamines, especially the chloropropyl homolog, showed clear mutagenicity in the strains with an intact excision repair system, S.typhimurium TA92, TA1975 and G46. Further, chloropropyl and chlorobutyl homologs showed interstrand cross-linking activity towards plasmid DNA. These results suggest that some chlorinated nitrosamines can act on DNA to form DNA cross-links, as observed in antitumor chloroethylnitrosoureas. Environmental nitrosamines are usually dealt with as potential carcinogens, but introduction of a chloro group has added the possibility of in vivo cross-linking activity, which is a classical and essential mechanism for antitumor agents. Therefore, the novel chlorinated nitrosamines examined in this study are proposed as new bifunctional antitumor lead compounds.

Antineoplastic Agents↗
PubMed2003

Progressive changes in arterial oxygenation during one-lung anaesthesia are related to the response to compression of the non-dependent lung.

BACKGROUND: Arterial oxygenation can change during one-lung ventilation for reasons that are not fully understood. METHODS: We studied patients during anaesthesia and one-lung ventilation, with an inspiratory oxygen fraction of 0.8. Arterial blood gas values were recorded every 10 s with a continuous intra-arterial sensor. The non-dependent lung was compressed several times during the surgical procedure, using a retractor. The change in Pa(O(2)) during and after compression of the non-dependent lung was measured. RESULTS: Pa(O(2)) increased significantly when the non-dependent lung was compressed, and decreased when the compression was released. The first compression of the non-dependent lung transiently increased Pa(O(2)), but the effect of the second compression on oxygenation was more marked and persistent. Pa(O(2)) increased by more than 13 kPa at 10 min after the second compression in four patients (responder group). Arterial oxygenation improved markedly in patients in this group during the surgical procedure. CONCLUSION: Oxygenation can improve during one-lung ventilation in some patients. This improvement is partly related to a marked increase in Pa(O(2)) during compression of the non-dependent lung.

Aged↗
PubMed2003

Tertiary nitrification in a new dual-medium aerated filter.

In an effort to develop an aerated filter with high nitrification capabilities, we formulated a new filter with 2 layers: the upper layer is filled with a plastic medium, and the lower with anthracite. We tested the filter in a pilot-scale apparatus on secondary-treated sewage, and in a small-scale apparatus on secondary-treated sewage and on artificial sewage. We evaluated the nitrification characteristics under various conditions of water velocity, air velocity, temperature, and pH. We designed a tertiary plant to treat 20,000 m3/day of secondary-treated sewage, using the new filter or a conventional filter. From these comparisons, it appeared that the dual-medium aerated filter had high nitrification capabilities and was an effective device for tertiary sewage treatment.

Air Movements↗
PubMed2003

[Showing no increase of C-reactive protein and developing non-bacterial median chest wound dehiscence after coronary artery bypass grafting].

A 72-year-old male underwent coronary artery bypass grafting for 3 vessels disease. After the operation, the peak C-reactive protein (CRP) level was 0.85 mg/dl and CRP levels stayed very low. Forty days after the operation the patient developed a progressive median chest wound dehiscence but the bacterial cultures were negative. In spite of conventional therapies such as debridement of necrotic tissue or irrigation, the wound granulation was underdeveloped. After 6 months an epidermis had developed to cover the wound.

Aged↗
PubMed2003

Identification of genes related to invasion and metastasis in pancreatic cancer by cDNA representational difference analysis.

The difference in gene expression between the highly invasive and metastatic cell line PC-1.0 and the weakly invasive and metastatic cell line PC-1 both derived from a pancreatic ductal carcinoma induced by N-nitrosobis (2-oxopropyl) amine (BOP) in Syrian golden hamster was examined using the Representational Difference Analysis (RDA) method. Within 8 clones (cDNA fragments) successfully isolated after subtraction hybridization of PC-1 cDNA from PC-1.0, 5 clones were shown to be specific or highly expressed in PC-1.0 as confirmed by RT-PCR. Among these 5 clones, two known genes, MAP kinase kinase 2 (MKK2) and phosphatidylinositol 4-kinase (PI4K230) were detected by gene sequencing. The specific expressions of MKK2 and PI4K230 in the highly invasive and metastatic cell line PC-1.0 were confirmed by RT-PCR and Northern blotting. By adding the CM of PC1.0 which included the cancer cell dissociation factor (DF), PC-1 cells began to dissociate and migrate from the colonies, and in addition the expression of MKK2 was found to be induced. On the other hand, the expression of PI4K230 was not induced in PC-1 cells by adding the CM of PC-1.0. Interestingly, in PC-1.0 the expression of PI4K230 was completely abolished and apoptosis induced by the PI3K inhibitor wortmannin. These results suggest that both MKK2 and PI4K230 are factors of a signal transduction pathway that might play an important role related to invasion and metastasis through the induction of cell motility and/or the inhibition of apoptosis.

1-Phosphatidylinositol 4-Kinase↗
PubMed2002

Characterization of 'adult-type' mast cells derived from human bone marrow CD34(+) cells cultured in the presence of stem cell factor and interleukin-6. Interleukin-4 is not required for constitutive expression of CD54, Fc epsilon RI alpha and chymase, and CD13 expression is reduced during differentiation.

BACKGROUND: In vitro-derived human mast cells exhibit different properties, depending in part on the source of progenitor cells. Most investigations have used fetal liver, cord blood or peripheral blood. Few have used adult bone marrow. OBJECTIVE: Human mast cells derived in vitro from the CD34(+) progenitors in bone marrow and cord blood that had been cultured with recombinant human stem cell factor (rhSCF) and recombinant human interleukin-6 (rhIL-6) were compared. METHODS AND RESULTS: After 12 weeks of culture, nearly all of the cells were mast cells, and nearly all of these had cytoplasmic granules containing both tryptase and chymase (MCTC type), stained metachromatically with acidic toluidine blue, and expressed CD117 on the cell surface. Both tryptase protein and mRNA were detected by two weeks of culture. Chymase mRNA and protein were detected at 4 weeks but not at 2 weeks of culture. By 12 weeks, chymase content per cell, measured by ELISA, was significantly higher (P < 0.05) in human bone marrow-derived mast cells (HBMMC) (5.6 +/- 0.9 pg) than in cord blood-derived mast cells (CBMC) (2.4 +/- 0.9 pg), whereas histamine and tryptase levels were not significantly different. Of the cluster designations tested, CD29, CD49d, CD51 and CD61 were strongly expressed on HBMMC. CD54 and Fc epsilon RI alpha also were expressed constitutively. Approximately half of CD34-sorted cells at day 0 were CD13(+) and this diminished as mast cell maturation occurred. Electron microscopy revealed that 12-week-old HBMMC had many secretory granules that contained spherical electron dense cores surrounded by electron lucent space, consistent with previous reports of immature MCTC cells developing in vivo. CONCLUSIONS: CD34(+) progenitors of human bone marrow are a rich source of mast cell progenitors capable of expressing granule and surface markers of mature mast cells in the presence of rhSCF and rhIL-6.

Antigens, CD↗
PubMed2002

Characterization of a cationic surfactant-resistant mutant isolated spontaneously from Escherichia coli.

AIMS: In order to investigate the mechanism of bacterial resistance to surfactants, a spontaneous mutant of Escherichia coli, OW66, resistant to a cationic surfactant cetyltrimethylammonium bromide (CTAB), was isolated and its physiological properties analysed. METHODS AND RESULTS: Strain OW66 grew in M9 medium containing CTAB at 45 micromol l(-1), whereas its parent strain, OW6, did not, even at 15 micromol l(-1). The mutant was also resistant to some other surfactants, antibiotics, heavy metals, organic solvents and oxidants examined. To determine the differences in physiology between strains OW66 and OW6, the compositions of their cell surface structures were analysed. In strain OW66, the relative content of OmpC in particular was higher than that of OmpF, whereas a reverse situation was seen in OW6 strain. The lipopolysaccharide (LPS) profile was different between these strains, and altered LPS in strain OW66 was suggested to be involved in the resistance to CTAB. CONCLUSIONS: A CTAB-resistant E. coli isolate possesses an altered outer membrane. SIGNIFICANCE AND IMPACT OF THE STUDY: Treatment with a relatively low concentration of CTAB was found to introduce multi-drug resistance into bacterial cells. This acquired resistance should be taken into account with the frequent use of surfactants in industries and various environments.

Bacterial Proteins↗
PubMed2002

Antibacterial activity of surfactants against Escherichia coli cells is influenced by carbon source and anaerobiosis.

AIMS: In order to clarify the involvement of an energy-yielding system in the antibacterial action of surfactants, the effects of carbon source and anaerobiosis during the growth period on the surfactant sensitivity of Escherichia coli cells were investigated. METHODS AND RESULTS: Cetyltrimethylammonium bromide (CTAB) and N-dodecyl-N,N-dimethylglycine, at relatively low concentrations, caused a delay in growth of E. coli cells. Cells grown in M9 medium supplemented with glycerol, succinate or acetate as a carbon source were more sensitive to surfactants and had a higher respiratory activity than those grown with glucose. Cultivation under anaerobiosis made cells resistant to CTAB. CONCLUSIONS: Bacterial sensitivity to surfactants was affected by carbon source and anaerobiosis. SIGNIFICANCE AND IMPACT OF THE STUDY: The results obtained should be helpful in determining suitable conditions of treatment in the practical use of surfactants for bacterial decontamination.

Anaerobiosis↗
PubMed2002

Combined minimally invasive approach using microsurgery and thoracoscopic surgery for resecting a dumbbell-type thoracic schwannoma.

We present a case of a thoracic schwannoma with an intravertebral component, a so-called "dumbbell-type" tumor, that was resected with a combined minimally invasive approach using microsurgery and thoracoscopic surgery simultaneously. A 31-year-old man was admitted to our hospital for treatment of a thoracic schwannoma 45 mm in maximal diameter at the level of the third thoracic vertebra. After the tumor was separated from intravertebral structures by using a microsurgical technique via the posterior approach with a hemilaminectomy and minimal unilateral facetectomy, the mass was removed completely by using video thoracoscopy. We stress that this approach should be the most useful and less invasive technique for treating the dumbbell-type of thoracic neurogenic tumor compared with a single or combination technique involving thoracotomy, multi-level laminectomy and costotransversectomy. Below, we make some notes on this technique from the neurosurgeon's standpoint.

Adult↗