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Y Ohshima

Publications and source records attributed to Y Ohshima.

At least 19 recordsLinked to original sources
PubMed2006

Levan (beta-2, 6-fructan), a major fraction of fermented soybean mucilage, displays immunostimulating properties via Toll-like receptor 4 signalling: induction of interleukin-12 production and suppression of T-helper type 2 response and immunoglobulin E production.

BACKGROUND: Products from the fermentation process of soybeans by Bacillus subtilis (natto) have been shown to possess anti-tumour and immunomodulatory activities. However, the formulations previously examined were not chemically pure, and this is a major limitation for elucidation of the molecular mechanisms for their activities. OBJECTIVE: In order to determine which components in soybean mucilage exert immunostimulatory activities, we examined the activities of their purified forms in vitro and in vivo in mice. METHODS: B. subtilis (natto) and fractions including levan and poly-gamma-glutamic acid (gamma-PGA) from fermented soybean mucilage were prepared. Levels of cytokine production by mouse macrophage cells after treatment with the fractions were measured by means of ELISA. In vivo effect of levan delivered intragastrically on ovalbumin (OVA)-specific T-helper type 2 (Th2) response with IgE production was examined in BALB/c mice that had been immunized intraperitoneally with OVA. Results Levan but neither gamma-PGA nor killed B. subtilis (natto) was found to exert strong activity to induce production of IL-12 p40 and TNF-alpha by macrophage cell lines in vitro. RESULTS: of experiments using Toll-like receptor (TLR) 4-deficient mice and TLR4-transfected human cell line indicated that TLR4 is involved in pattern recognition of levan. Oral administration of levan in vivo significantly reduced the serum levels of OVA-specific IgE and Th2 response to OVA in mice immunized with OVA. CONCLUSION: Levan is an immunostimulatory moiety in products from the fermentation process of B. subtilis (natto) and may be useful for prevention of allergic disorders with IgE production.

Adjuvants, Immunologic↗
PubMed2005

Quantitative unspun-urine microscopy as a quick, reliable examination for bacteriuria.

The diagnosis and treatment of urinary infection are often delayed, causing renal damage, largely because of the unavailability of quick, accurate, diagnostic examinations. Three hundred and twenty-five urine samples from 130 patients were examined for significant bacteriuria using the standard culture method. The urine samples were also examined using the Gram-stain method and quantitative unspun-urine microscopy. When particles could not be distinguished definitely as bacilli by quantitative microscopy, the unspun urine was examined on a slide glass using oil-immersion microscopy at x 1000 magnification. Significant bacteriuria in 37 urine samples was detected by bacterial culture. Using quantitative microscopy, rods were found in 30, cocci in a chain in 3, and indefinite particles in 44 samples. In the 44 indefinite samples, oil-immersion microscopy was able to distinguish rods in one, cocci in a chain in one, cocci in a cluster in two, and negative in 40, which were confirmed by culture as rods, streptococci, staphylococci, and negative, respectively. The quantitative microscopy method was similarly reliable (94.6% sensitivity, 99.3% specificity) for diagnosis of significant bacteriuria when compared with the Gram-stain method (89.2% sensitivity, 98.6% specificity). Quantitative unspun-urine microscopy, confirmed by oil-immersion, is a quick, reliable method for diagnosis of significant bacteriuria, and is considered to be useful for early diagnosis of urinary infection.

Adolescent↗
PubMed2003

Association between interleukin-18 gene polymorphism 105A/C and asthma.

BACKGROUND: IL-18 has been shown to exert anti-allergic or allergy-promoting activities, but the existence of genetic polymorphisms in the coding regions of IL-18 gene has not been demonstrated. OBJECTIVE: The aim of this study was to investigate whether polymorphism is present in the coding regions of the IL-18 gene and, if so, to further analyse the association between polymorphism and asthma in a case-control study. METHODS: We screened the coding regions of the IL-18 gene for polymorphisms by using PCRsingle-stranded conformation polymorphism and direct sequencing of PCR products, followed by analysis of the association between polymorphism and asthma. RESULTS: We identified one polymorphism (105A/C) in the coding regions. The frequency of the 105A allele was significantly higher in asthmatic patients than in controls (P<0.01; odds ratio (OR)=1.83 (1.37-2.26)). Significant linkage disequilibrium was observed between the 105A/C and -137G/C polymorphisms in the 5' flanking region of the IL-18 gene (D=0.58, P<0.0001). However, in asthmatic patients the 105A allele was not associated with either total serum IgE or IL-18 levels. CONCLUSION: The 105A/C polymorphism of the IL-18 gene may be associated with the pathogenesis of asthma.

Adolescent↗
PubMed2001

Important role of junctophilin in nematode motor function.

Junctional complexes between the plasma membrane and endoplasmic/sarcoplasmic reticulum are shared by excitable cells and seem to be the structural ground for cross-talk between cell-surface and intracellular ionic channels. Our current studies have identified junctophilins (JPs) as members of a novel transmembrane protein family in the junctional membrane complex. Biochemical and gene-knockout studies have suggested that JPs contribute to the formation of the junctional membrane complex by spanning the intracellular store membrane and interacting with the plasma membrane. We report here invertebrate JPs in fruit fly and nematode. Three distinct JP subtype genes are found in the mammalian genome, while a single JP gene exists in either invertebrate genome. Mammalian and invertebrate JPs share characteristic structural features, although some intervening sequences are found in invertebrate JPs. A reporter assay indicated that the JP gene is predominantly activated in muscle cells in nematode. Nematodes, in which expression of JP was inhibited by RNA-mediated interference (RNAi), showed hypolocomotion. Taking account of the cell-type-specific expression and data from previous reports, the hypolocomotion is likely to be due to the deficiency of junctional membrane structures and the resulting reduction of Ca(2+) signaling during excitation-contraction coupling in muscle cells.

Animals↗
PubMed2001

Increased oxidative stress in childhood atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease of unknown etiology. To examine the involvement of impaired homeostasis of oxygen/nitrogen radicals in childhood AD, we compared the levels of urinary 8-hydroxy-2'-deoxyguanosine (marker of oxidative stress), nitrite/nitrate (marker of nitric oxide synthesis) and selenium (marker of selenium store) in 27 children with AD to those of 25 healthy control children. Urinary 8-hydroxy-2'-deoxyguanosine was significantly higher and nitrite/nitrate levels were significantly lower in patients with AD than in the control. Urinary selenium levels were similar in both groups. Our findings suggest that impaired homeostasis of oxygen/nitrogen radicals and increased oxidative stress are involved in the pathophysiology of childhood AD, and indicate that suppression of oxidative stress might be a potentially useful strategy for the treatment of AD.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2001

Histone deacetylase inhibitors such as sodium butyrate and trichostatin A induce apoptosis through an increase of the bcl-2-related protein Bad.

The effects of sodium butyrate (SB) and trichostatin A (TSA) on cell proliferation andapoptosis against human glioma T98G, U251MG, and U877MG cells were investigated. Upon exposure to either SB or TSA, cell proliferation was reduced, and apoptosis detected by DNA fragmentation analysis and the cleavage of CPP32 was induced. Previously, we reported that SB increased the expression levels of p21 (WAF-1) and inhibited G1-S transition of the cell cycle. In this study, we showed that TSA also increased p21 expression, suggesting that histone deacetylase (HDAC) inhibitors may up-regulate p21 protein in common and thus arrest proliferation in the G1 phase of the cell cycle. To further determine the underlying molecular mechanisms of apoptosis with either SB or TSA treatment, we studied the expression levels of apoptosis-related proteins in human glioma cells. SB increased the expression of the Bad protein, although the expression of Bcl-2, Bcl-xL, Bax, and Fas was not changed by theaddition of SB. TSA treatment also up-regulated the expression of Bad protein. The results suggest that HDAC inhibitors such as SB and TSA induce apoptosis through an increase in Bad protein in human glioma cells in vitro.

Apoptosis↗
PubMed2001

DAF-7/TGF-beta expression required for the normal larval development in C. elegans is controlled by a presumed guanylyl cyclase DAF-11.

In C. elegans development, unfavorable growth conditions lead a larva to an arrested and enduring form called a dauer. To elucidate components upstream of DAF-7/TGF-beta in this control pathway, we isolated a mutant that was defective in daf-7 promoter::gfp reporter expression and showed an arrested (dauer-constitutive) phenotype. It has a new mutation in the daf-11 gene encoding a transmembrane guanylyl cyclase. We show that daf-11 gene and a related gene daf-21 act upstream of daf-7, and cilium-related genes che-2 and che-3 are placed between daf-11 and daf-7, in the genetic pathway controlling dauer formation. Expression of daf-11 cDNA by cell specific promoters suggests that daf-11 acts cell autonomously in ASI chemosensory neurons for daf-7 expression.

Alleles↗
PubMed2001

Mutation in the prp12+ gene encoding a homolog of SAP130/SF3b130 causes differential inhibition of pre-mRNA splicing and arrest of cell-cycle progression in Schizosaccharomyces pombe.

prp12-1 is one of the mutants defective in pre-mRNA splicing at a nonpermissive temperature in Schizosaccharomyces pombe. We found that the prp12+ gene encodes a protein highly homologous with a human splicing factor, SAP130/SF3b130, a subunit of a U2 snRNP-associated complex SF3b. Prp12p was shown to interact genetically with Prp10p that is a homolog of SAP155/SF3b155, another subunit in SF3b, suggesting that Prp12p is a functional homolog of human SAP130/SF3b130. Prp12p tagged with GFP is uniformly localized in the nuclear DNA region. In addition to pre-mRNA splicing defects, the prp12-1 mutant produced elongated cells, a typical phenotype of cell division cycle (cdc) mutants, suggesting a possible link between pre-mRNA splicing and cell-cycle progression. We examined kinetics of splicing defects in prp12-1 and several other prp mutants using northern blot hybridization and found that, among all the tested pre-mRNAs, only Tflld pre-mRNA with low splicing efficiency showed detectable splicing defects at the nonpermissive temperature in prp12-1. In addition, we found that other prp mutants with the cdc phenotype also showed differential splicing defects in tested pre-mRNAs at the nonpermissive temperature. On the other hand, prp mutants that do not exhibit the cdc phenotype showed a rapid and complete block of pre-mRNA splicing in all the tested pre-mRNAs at the nonpermissive temperature, indicating that prp mutants with weak splicing defects have a tendency to exhibit the cdc phenotype. These results suggest that the cdc phenotype in prp12-1 is caused by a selective reduction of spliced transcripts encoding a protein (or proteins) required for G2/M transition.

Amino Acid Sequence↗
PubMed2001

No evidence for AT2R gene derangement in human urinary tract anomalies.

BACKGROUND: It has been recently found that mice, especially males, with a disrupted angiotensin type 2 receptor (AT2R) gene, which is located on the X-chromosome, often have a range of congenital anomalies of the kidney and urinary tract (CAKUT), including renal hypoplasia, and that Caucasian male patients with ureteropelvic junction stenosis (UPJ) and multicystic dysplastic kidneys frequently have A-G transition in intron 1 of the AT2R gene. We have previously found that renal hypoplasia is remarkably predominant in Japanese boys. METHODS: We investigated sex ratios for the frequency of each CAKUT. The frequency of the A-G transition between the controls and 66 Japanese boys with CAKUT were compared. There was renal hypoplasia in 16, UPJ in 17, vesicoureteral in 20, and other anomalies in 13. We also investigated whether any mutations in AT2R genes were detectable in patients with renal hypoplasia. RESULTS: In contrast to mice with a disruption of the AT2R gene, the male-to-female ratios in human patients proved to be considerably variable: 16 for renal hypoplasia, 2.1 for UPJ, 0.8 for vesicoureteral, and 1.2 for others. The frequency of the A-G transition was not different between the control population and the patients with CAKUT [31 of 102 (30%) vs. 23 of 66 (35%), respectively]. A sequencing study disclosed no mutations in nine boys with renal hypoplasia. CONCLUSIONS: These findings indicate that the AT2R gene may not play a major role in the development of renal hypoplasia and other CAKUT in humans, at least in the Japanese population.

Alleles↗
PubMed2001

Primary total knee arthroplasty for supracondylar/condylar femoral fracture in osteoarthritic knees.

Supracondylar or condylar femoral fractures require extended treatment and often result in loss of knee range of motion. We present 3 cases in which femoral fractures and preexisting painful knees secondary to osteoarthritis were treated using total knee arthroplasty with a stemmed femoral implant. The patients were all women aged 83, 84, and 87 years old. All fractures united within 3 months, and the patients could walk with 1 cane within 2 months. Primary total knee arthroplasty should be considered as a treatment for supracondylar/condylar femoral fractures in osteoarthritic knees.

Aged↗
PubMed2001

Protein anatomy: structure and function of peptide fragments corresponding to the secondary structure units of barnase.

Globular proteins can be decomposed into several modules or secondary structure units. It is useful to investigate the functions of such structural units in order to understand the folding units of proteins. In our previous work, barnase was divided into six peptide fragments corresponding to modules, and some of them were shown to have RNA-binding and RNase activity [Yanagawa, et al. (1993) J. Biol. Chem. 268, 5861-5865]. Barnase mutant proteins obtained by permutation of the structural units also had RNase activity [Tsuji, T. et al. (1999) J. Mol. Biol. 286, 1581-1596]. Here we investigated the structure and function of peptide fragments corresponding to secondary structure units of barnase. The results of circular dichroism spectroscopy indicated that some of the peptide fragments form helical structures in aqueous solutions containing over 30% 2,2,2-trifluoroethanol, and the S6 (94-110) peptide fragment is induced to form a beta-sheet structure in the presence of RNA. The S6 peptide fragment forms aggregate complexes with RNA. Electron microscopic analysis showed that the aggregate complexes were comprised of filaments. These results indicate that not only modules but also secondary structure units dissected from a globular protein have functional and structure-forming capabilities.

Amino Acid Sequence↗
PubMed2001

Mutational analysis of regulatory cis-acting elements for the transcriptional activation of the dmsCBA operon in Rhodobacter sphaeroides f. sp. denitrificans.

Four direct repeats of a 10-nt sequence, called dms boxes, are located upstream of the dmsCBA operon encoding dimethyl sulfoxide (DMSO) reductase in Rhodobacter sphaeroides f. sp. denitrificans IL106. Two dms boxes 1 and 2 have been shown to be binding sites of DmsR protein, a response regulator of a two-component system involved in the anaerobic induction by DMSO of DMSO reductase synthesis. In this study, functions of four dms boxes in the transcriptional regulation of the dmsCBA operon were investigated. The transcription start site of the dmsCBA genes was identified at the distance of 23 nt downstream of the closest dms box 4. Expression of the dmsC-lacZ gene fusion which included the dmsCBA promoter region containing the dms boxes was examined and its anaerobic induction by DMSO and DmsR-dependency were demonstrated in the phototroph. The examination with nucleotide substitutions in the four respective dms boxes showed that the set of four dms boxes is required for the dmsCBA operon activation. Moreover, the importance of the nucleotide sequence of TTCAC in dms box 4 and of A at the center in dms box 1 was significantly shown. These facts suggest that the pentad nucleotides TTCAC and TTAAC in the dms boxes serve as cis-acting elements in the transcriptional activation of the dmsCBA operon.

Anaerobiosis↗
PubMed2001

Low aquaporin content and low osmotic water permeability of the plasma and vacuolar membranes of a CAM plant Graptopetalum paraguayense: comparison with radish.

Aquaporin facilitates the osmotic water transport across biomembranes and is involved in the transcellular and intracellular water flow in plants. We immunochemically quantified the aquaporin level in leaf plasma membranes (PM) and tonoplast of Graptopetalum paraguayense, a Crassulacean acid metabolism (CAM) plant. The aquaporin content in the Graptopetalum tonoplast was approximately 1% of that of radish. The content was calculated to be about 3 microg mg(-1) of tonoplast protein. The level of PM aquaporin in Graptopetalum was determined to be less than 20% of that of radish, in which an aquaporin was a major protein of the PM. The PM aquaporin was detected in the mesophyll tissue of Graptopetalum leaf by tissue print immunoblotting. The osmotic water permeability of PM and tonoplast vesicles prepared from both plants was determined with a stopped-flow spectrophotometer. The water permeability of PM was lower than that of the tonoplast in both plants. The Graptopetalum PM vesicles hardly showed water permeability, although the tonoplast showed a relatively high permeability. The water permeability changed depending on the assay temperature and was also partially inhibited by a sulfhydryl reagent. Furthermore, measurement of the rate of swelling and shrinking in different mannitol concentrations revealed that the protoplasts of Graptopetalum showed low water permeability. These results suggest that the low content of aquaporins in PM and tonoplast is one of the causes of the low water permeability of GRAPTOPETALUM: The relationship between the water-storage function of succulent leaves of CAM plants and the low aquaporin level is also discussed.

Amino Acid Sequence↗
PubMed2001

Involvement of thioredoxin in the regulation of growth hormone secretion in rat pituitary cell cultures.

We report here an examination of the effect of thioredoxin (TRX) on the secretion of growth hormone (GH) from rat anterior pituitary cells in vitro. Treatment of rat pituitary cells with growth hormone-releasing factor (GRF), but not GH, led to a significant increase in intracellular TRX protein levels. GRF, recombinant human TRX (rhTRX), and a combination thereof were all shown to induce immediate GH secretion from pituitary cells, as evidenced by perifusion experiments. RhTRX, but not other reducing agents such as beta-mercaptoethanol and N-acetyl-L-cysteine, augmented GRF-stimulated and -unstimulated GH secretion from rat pituitary cells in a dose-dependent manner. RhTRX did not significantly affect the GH mRNA expression of pituitary cells stimulated in the presence or absence of GRF. In addition, rhTRX-augmented GH secretion was not significantly affected by the presence of cycloheximide. Collectively, these findings suggest that TRX is induced by stimulation with GRF and plays a regulatory role in GH secretion from rat anterior pituitary cells by enhancing the secretion of stored GH, rather than by the synthesis of GH.

Animals↗
PubMed2001

Significance of ACE genotypes and medical treatments in childhood focal glomerulosclerosis.

BACKGROUND: There is little information on the significance of angiotensin-converting enzyme (ACE) genotypes and medical treatments in children with primary focal segmental glomerulosclerosis (FSGS). METHODS: A multicenter retrospective study was performed on the role of ACE genotypes and medical treatments in 43 Japanese children with FSGS (20 males and 23 females), including 17 children who progressed to end-stage renal failure during the mean observation period of 6.9 +/- (SD) 5.0 years. RESULTS: The incidence of the D allele of the ACE gene was higher in the whole group of 43 children with FSGS and in a subgroup of 28 steroid-resistant FSGS children (p < 0.05) than in the 130 children of the healthy control group (0.48, 0.48, and 0.33, respectively). ACE genotypes did not affect renal survival in the whole FSGS group nor in the steroid-resistant subgroup. Among the 28 steroid-resistant children, treatment with ciclosporin was effective in delaying the development of end-stage renal failure (p = 0.044), independently of other treatment regimens. CONCLUSION: The present study of Japanese children with FSGS showed that the D allele of the ACE gene is associated with the development of FSGS, but not associated with the progression of FSGS which was greatly ameliorated with ciclosporin, irrespective of ACE genotypes.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

Functional modification of cytochrome c by peroxynitrite in an electron transfer reaction.

The redox reaction of cytochrome c after modification with peroxynitrite under physiological conditions was investigated. Cytochrome c was treated with a bolus of synthetic peroxynitrite at a sub-millimolar concentration, and then subjected to reduction by superoxide and oxidation by hydrogen peroxide. The ability for the membrane potential formation in the mitochondrial respiratory chain was also evaluated. After the treatment with peroxynitrite, the cytochrome c molecule was mono-nitrated mainly at a tyrosine residue, using liquid chromatography-electrospray ionizing mass spectrometry (LC-ESI-MS) and HPLC. Although the redox capacity of cytochrome c was not affected by the peroxynitrite treatment, the oxidation of ferrocytochrome c to ferricytochrome c by hydrogen peroxide was accelerated. When cytochrome c was treated with peroxynitrite in the presence of 5-methoxytryptamine, an inhibitor for the tyrosine nitration by peroxynitrite, the acceleration of hydrogen peroxide-mediated oxidation was suppressed. It was also found that the formation of membrane potential in the rat liver mitochondria was suppressed when peroxynitrite-treated cytochrome c was used instead of the intact cytochrome c in vitro. From these results, we concluded that the peroxynitrite-treated cytochrome c was nitrated at a tyrosine residue and became more susceptible to oxidation by hydrogen peroxide, concomitantly losing the ability to transfer electrons in the mitochondrial respiratory chain. It is suggested that the peroxynitrite-induced modification of cytochrome c increases the susceptibility to non-physiological oxidants, and may cause dysfunction of mitochondria by suppressing of membrane potential.

Animals↗