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Biomedical subjects

H Ohashi

Publications and source records attributed to H Ohashi.

At least 109 records · Page 6Linked to original sources
PubMed2000

Batista's operation with coronary artery bypass grafting and mitral valve plasty for ischemic dilated cardiomyopathy.

A 52-year-old male was admitted for angina pectoris and congestive heart failure classified as New York Heart Association class III. Coronary angiography showed 95% stenosis in the left anterior descending artery, 99% stenosis in the first diagonal branch, total occlusion in the left circumflex artery, and a hypoplastic right coronary artery. Left ventriculography showed a severely dilated left ventricle (ejection fraction 20%) and mild mitral regurgitation. In the myocardial scintigram using 99m-tetrofosmin, there was no viability in the posterolateral wall although the other wall was viable. Partial left ventriculectomy, which is called Batista's operation, coronary artery bypass grafting and Alfieri's mitral valve plasty were performed concomitantly. Postoperatively, the ejection fraction was improved to 39%, and all grafts were patent. The patient was discharged in New York Heart Association class I. We concluded that to succeed in partial left ventriculectomy for ischemic dilated cardiomyopathy, not only should there be no viability in the posterolateral wall to be resected for volume reduction, but the coronary artery which perfuses the residual myocardium with viability should be graftable.

Cardiac Surgical Procedures↗
PubMed2000

Current status of Helicobacter contamination of laboratory mice, rats, gerbils, and house musk shrews in Japan.

The current status of Helicobacter contamination of laboratory mice, rats, gerbils, and house musk shrews from 47, 10, 4, and 3 colonies, respectively, in Japan was studied. Helicobacter was detected by reverse transcription (RT)-nested polymerase chain reaction (PCR) with Helicobacter genus-specific primers by using feces obtained from the animals. H. hepaticus, H. muridarum, H. bilis, H. rodentium, "Flexispira rappini", and "H. suncus" were identified with species-specific primers. Other species of Helicobacter were identified by sequencing of PCR products amplified with genus-specific primers. For mice, H. hepaticus, H. bilis, H. rodentium including H. rodentium-like organism, "H. typhlonicus"-like organism, and H. westmeadii-like organism were detected from 12 (25.5%), 1 (2.1%), 18 (38.3%), 1 (2.1%), and 1 (2.1%) colonies, respectively. Forty-seven (5.7%) mice from six (12.8%) colonies were contaminated with both H. hepaticus and H. rodentium. H. rodentium was detected in rats from three (30.0%) colonies. In gerbils, H. hepaticus was detected in three (75.0%) colonies, but other species of Helicobacter were not detected. In house musk shrews, "H. suncus" was detected in animals from two (66.7%) colonies. Visible lesions in the liver, which showed multiple pale to white foci, were observed in 6/42, 5/174, and 1/21 mice infected with H. hepaticus, H. rodentium, and H. hepaticus/H. rodentium, respectively, and 1/14 gerbils infected with H. hepaticus. The results suggest the prevalence of these species of Helicobacter in mice, rats, gerbils, and house musk shrews in Japan.

Animals↗
PubMed2000

Severe hypercalcaemia and respiratory insufficiency associated with infantile hypophosphatasia caused by two novel mutations of the tissue-nonspecific alkaline phosphatase gene.

UNLABELLED: We report the case of a male patient with infantile hypophosphatasia associated with severe hypercalcaemia and mild respiratory insufficiency. At the age of 2 months, severe hypercalcaemia, low levels of serum alkaline phosphatase activity, and elevated urinary excretion of calcium and phosphoethanolamine were noted. Radiological findings showed generalized osteopenia and disturbed and irregular ossification of the metaphyses. Their involvement had spontaneously improved at the age of 6 months. A genetic study revealed that the tissue-nonspecific alkaline phosphatase gene of the patient had two novel mutations, K207E and G409C, derived from the mother and father, respectively. A reconsitution experiment revealed that both mutant gene products had low but significant enzymatic activity. CONCLUSION: The detection of tissue-nonspecific alkaline phosphatase gene mutations and expression studies to determine the enzymatic activity of mutant gene products was useful for assessing the clinical course of this patient with hypophosphatasia.

Alkaline Phosphatase↗
PubMed2000

Identification of a gene disrupted by inv(11)(q13.5;q25) in a patient with left-right axis malformation.

An inv(11)(q13.5;q25) inversion was previously identified in a 9-month-old male patient with complex cyanotic heart defects, altered lung lobation, symmetric liver, and abnormally lobulated spleen (polysplenia). This chromosomal rearrangement was inherited from the phenotypically normal father. We termed these regions DHTX-A (disrupted in heterotaxy)-- A at 11q13.5 and DHTX-B at 11q25. Here, we report the isolation and characterization of the inversion breakpoints and the gene that is disrupted by the DHTX-A breakpoint. The putative DHTX is identical to the UVRAG gene, which was originally identified as a gene that complements the UV sensitivity of xeroderma pigmentosum complementation group C. The 4-kb mRNA was found to be encoded by a large gene, at least 300 kb long, composed of 15 exons. The function of the gene product remains largely unknown. However, the near central portion of the UVRAG protein is predicted to contain a coiled-coil domain, which has been implicated in mediating protein-protein interactions. Southern analyses and fluorescence in situ hybridization (FISH) revealed that the DHTX-A breakpoint in the patient and his father lies within the intron between exons 6 and 7 of UVRAG. Northern blot analysis indicated strong expression in human fetal and adult tissues and in mouse embryonic day-7 and adult tissues, respectively. Whole mount in situ hybridization also showed that the Uvrag gene is expressed in the presomite-stage embryo. Several hypotheses are discussed to explain the relationship between the chromosomal inversion and the accompanying phenotypes.

Amino Acid Sequence↗
PubMed2000

Lignans causing photodiscoloration of Tsuga heterophylla: 8-hydroxy-oxomatairesinol from sapwood.

A lignan, (8S,8'S,)-(+)-8-hydroxy-oxomatairesinol, has been isolated from the sapwood of Tsuga heterophylla (western hemlock, Pinaceae). The known lignans matairesinol, lariciresinol and secoisolariciresinol were also obtained. The structure of the compound was established by 1D and 2D NMR spectroscopy. Results of the light-irradiation test of the lignans from T. heterophylla are also reported.

Chromatography, High Pressure Liquid↗
PubMed2000

Effect of particles and interface conditions on fibrous tissue interposition between bone and implant. A particle challenge model in rabbit.

Interposed fibrous tissue at bone-implant interfaces was quantitatively measured in the presence or absence of polyethylene (PE) or alumina particles. Three different conditions of the interface were designed by implanting a pre-polymerized polymethylmethacrylate (PMMA) plug (plug group), a doughy PMMA (injection group) and a hydroxyapatite (HA) plug (HA group) in the hole drilled at the intercondylar notch of rabbit knees. PE (170+/-18 microm) or alumina particles (88+/-26 microm) were repeatedly administered into the knee joints at one month intervals (six times). All animals were sacrificed seven months after the implantation. The bone-implant interface was histomorphometrically examined using undecalcified ground sections. In the plug group, the PE particles significantly increased the extent of the interposed fibrous tissue (p < 0.05), while the alumina particles showed no effect. In contrast, both particles showed no significant effects in the injection and the HA groups. These results indicate that both particle characteristics and conditions of the bone-implant interface affected particle-induced fibrous tissue interposition. The loose PMMA plug with PE particles induced the greatest amount of fibrous tissue interposition.

Journal Article↗
PubMed2000

Blockade of TGF-beta by in vivo gene transfer of a soluble TGF-beta type II receptor in the muscle inhibits corneal opacification, edema and angiogenesis.

Accumulating evidence suggests the involvement of TGF-beta in the process of corneal opacity, which is one of the serious causes of visual loss. However, whether TGF-beta is indeed critical for the pathogenesis remains unknown. We constructed an adenovirus expressing an entire ectodomain of the human type II TGF-beta receptor fused to Fc portion of human IgG (AdTbeta-ExR): this soluble receptor is secreted from AdTbeta-ExR-infected cells, binds to TGF-beta and inhibits TGF-beta signaling. When AdTbeta-ExR was injected into the femoral muscle of Balb/c mice, a high level of the soluble receptor protein (2.0-3.5 x 10(3) pM) was detectable in the serum and in the ocular fluid for at least 10 days. In the mice subjected to corneal injury with silver nitrate and to intramuscular injection with either saline or a control adenovirus expressing beta-galactosidase (AdLacZ), corneal opacification composed of extracellular matrix (ECM) accumulation, of infiltration of neutrophils and monocytes/macrophages, and of angiogenesis were all induced. In contrast, they were markedly reduced in the mice injected with AdTbeta-ExR. Immunohistochemical analysis revealed that TGF-beta, fibronectin, macrophage chemoattractant protein-1, and vascular endothelial growth factor were densely stained in the edge of wounded cornea, but they were scarcely present in the injured-cornea of AdTbeta-ExR-treated mice. Our results demonstrate that TGF-beta indeed plays a critical role in the process of cornea opacification, and that adenovirus-mediated expression of a soluble TGF-beta receptor can be therapeutically useful.

Adenoviridae↗
PubMed2000

Clonality analysis by methylation-specific PCR for the human androgen-receptor gene (HUMARA-MSP).

The human androgen-receptor gene (HUMARA) has been used for analysis of X chromosome inactivation (XCI) pattern because of a polymorphic short tandem repeat (STR) near the 5'-promoter region correlated with XCI. We introduce a novel method to analyze XCI pattern, named HUMARA methylation-specific PCR (HUMARA-MSP) assay, which analyzes methylation status of the HUMARA gene by bisulfite modification instead of a methylation-sensitive restriction enzyme. Although the original MSP method shows whether there is a methylated band or not, our HUMARA-MSP method identifies the patterns of methylated and unmethylated bands. Because this method identifies either unmethylated or methylated alleles in each PCR tube and shows opposite band patterns dependent on methylation status, we can assess the XCI pattern independently twice. This method can avoid false results by incomplete enzyme digestion and incomplete bisulfite modification will not affect the results. Extremely small quantities of samples, such as hematopoietic colonies, were also available for HUMARA-MSP assay. Because DNA modified by sodium bisulfite is also available for assessment of methylation status of other genes by setting specific primers for them, we performed the simultaneous assessment of clonality and aberrant hypermethylation of p15INK4B gene in myelodysplastic syndromes. These simultaneous assessments were easily possible and provided much information despite requiring only a small volume of DNA. The HUMARA-MSP assay may facilitate the analyses for pathogenesis of hematological disorders because of its simplicity, sensitivity and wide applicability. Leukemia (2000) 14, 207-212.

Base Sequence↗
PubMed2000

Methylation status of the p15INK4B gene in hematopoietic progenitors and peripheral blood cells in myelodysplastic syndromes.

We previously reported that the hypermethylation of the p15INK4B gene promoter was frequently observed in myelodysplastic syndromes (MDS), and that it may be associated with disease progression. An unanswered question is whether p15INK4B gene methylation is restricted to undifferentiated blastic cells, or whether differentiated cells such as granulocytes or erythrocytes of MDS origin also harbor this epigenetic alteration. In this study, we analyzed the methylation status of the p15INK4B gene in MDS by the methylation-specific PCR (MSP) method, which is more sensitive than Southern blotting. The bone marrow mononuclear cells (BM-MNCs) of 23 MDS patients were analyzed, and six of them showed p15INK4B methylation. Progenitor assay with methylcellulose medium was also performed in all patients. In two of the six patients with p15INK4B-methylated BM-MNCs, erythroid and/or non-erythroid colonies formed were subjected to molecular analysis. Colonies with and without p15INK4B methylation were detected in both patients. Furthermore, X-chromosome inactivation (XCI) pattern of each colony was simultaneously determined by MSP-based human androgen receptor gene analysis (HUMARA-MSP), and all p15INK4B-methylated colonies showed the same XCI pattern, which was dominant among the colonies, while p15INK4B-unmethylated colonies showed both patterns of XCI, in each of the two patients. We then examined the methylation status of the p15INK4B gene of granulocyte (PB-PMN) fractions from 10 patients with available peripheral blood cells. In all four patients with p15INK4B-methylated BM-MNCs, their PB-PMNs showed p15INK4B methylation. These results suggest that p15INK4B methylation in hematopoietic cells in MDS patients is restricted to the MDS clone but not necessarily to blast cells.

Acute Disease↗
PubMed2000

Genetic evidence for a novel gene(s) involved in urogenital development on 10q26.

BACKGROUND: Although the frequent association between distal 10q monosomy and urogenital anomalies suggests the presence of a gene(s) for urogenital development on distal 10q, molecular deletion mapping has not been performed for the putative gene(s). In this study, we examined genotype-phenotype correlations in patients with distal 10q monosomy. METHODS: This study consisted of six karyotypic males (cases 1 through 6) and four karyotypic females (cases 7 through 10) with 10q26 monosomy. Cases 3 through 5 and 7 through 10 had urinary anomalies such as vesicoureteral reflux and hypoplastic kidney, and cases 1 through 6, 8, and 9 exhibited genital anomalies such as micropenis, hypospadias, cryptorchidism, and hypoplastic labia majora. Fluorescence in situ hybridization (FISH) for 10q telomere, whole chromosome 10 painting, and microsatellite analysis for 35 loci on distal 10q were performed in cases 1 through 8. RESULTS: FISH and whole chromosome painting confirmed distal 10q monosomy in cases 1 through 8. Microsatellite analysis revealed that hemizygosity for the region distal to D10S186 was shared by cases with urinary anomalies and that for the region distal to D10S1248 was common to cases with genital anomalies. Furthermore, it was indicated that PAX2, GFRA1, and EMX2 on distal 10q, in which the deletions could affect urinary and/or genital development, were present in two copies in cases 1 through 8. CONCLUSIONS: The results suggest that a novel gene(s) for urinary development and that for genital development reside in the approximately 20 cM region distal to D10S186 and in the approximately 10 cM region distal to D10S1248, respectively, although it remains to be determined whether the two types of genes are identical or different.

Adolescent↗
PubMed2000

Histologic and mechanical evaluation of impacted morcellized cancellous allografts in rabbits: comparison with hydroxyapatite granules.

The bioactivity and mechanical properties of morcellized allografts and hydroxyapatite (HA) granules were evaluated in a rabbit model. Allografts were replaced by viable trabecular structures within 8 weeks. The yield strength and stiffness of allografts were within normal cancellous bone levels by 3 weeks and were maintained afterward. The amount of newly formed bone around HA granules was comparable to that around allografts. The yield strength and stiffness of HA granules were significantly higher than those of allografts at 3 and 12 weeks. Allografts offer the advantage of being replaced by host-bone without significant deterioration in mechanical properties over the course of remodeling. HA granules can also be used for a bone substitute given their bioactivity in bone conduction and superiority in mechanical properties to allografts.

Animals↗
PubMed2000

Clinical significance of major and minor bcr/abl chimeric transcripts in essential thrombocythemia.

BACKGROUND: Contradictory results have been reported in terms of detecting bcr/abl transcripts in patients with essential thrombocythemia. The aim of this study was to investigate whether the bcr/abl transcript could be found in patients with essential thrombocythemia (ET). METHODS: The bcr/abl transcript was amplified by the RT-nested PCR method using RNA extract from leukocytes taken from 14 essential thrombocythemia patients. The amplified DNAs were electrophoresed in 1% agarose and visualized with ethidium bromide. The DNA bands associated with the bcr/abl transcript were then extracted and followed by DNA sequence analysis. RESULTS: Major bcr/abl transcripts of the b3a2 type and minor ones of the e1a2 type were found in one and two ET patients, respectively. The incidence of bcr/abl transcripts was 21.4% (three of 14 patients). CONCLUSION: Our experiments confirmed that bcr/abl transcripts are present in some patients with essential thrombocythemia.

Adult↗
PubMed2000

Characteristics of ropivacaine block of Na+ channels in rat dorsal root ganglion neurons.

UNLABELLED: When used for epidural anesthesia, ropivacaine can produce a satisfactory sensory block with a minor motor block. We investigated its effect on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na(+) currents in rat dorsal root ganglion (DRG) neurons to elucidate the mechanisms underlying the above effects. Whole-cell patch-clamp recordings were made from enzymatically dissociated neurons from rat DRG. A TTX-S Na(+) current was recorded preferentially from large DRG neurons and a TTX-R Na(+) current preferentially from small ones. Ropivacaine shifted the activation curve for the TTX-R Na(+) channel in the depolarizing direction and the inactivation curve for both types of Na(+) channel in the hyperpolarizing direction. Ropivacaine blocked TTX-S and TTX-R Na(+) currents, but its half-maximum inhibitory concentration (IC(50)) was significantly lower for the latter current (116 +/- 35 vs 54 +/- 14 microM; P: < 0.01); similar IC(50) values were obtained with the (R)-isomer of ropivacaine. Ropivacaine produced a use-dependent block of both types of Na(+) channels. Ropivacaine preferentially blocks TTX-R Na(+) channels over TTX-S Na(+) channels. We conclude that because TTX-R Na(+) channels exist mainly in small DRG neurons (which are responsible for nociceptive sensation), such selective action of ropivacaine could underlie the differential block observed during epidural anesthesia with this drug. IMPLICATIONS: Whole-cell patch-clamp recordings of tetrodotoxin-sensitive and tetrodotoxin-resistant Na(+) currents in rat dorsal root ganglion neurons showed ropivacaine preferentially blocked tetrodotoxin-resistant Na(+) channels over tetrodotoxin-sensitive Na(+) channels. This could provide a desirable differential sensory blockade during epidural anesthesia using ropivacaine.

Amides↗
PubMed2000

BodyMap: a collection of 3' ESTs for analysis of human gene expression information.

BodyMap is a collection of site-directed 3' expressed sequence tags (ESTs) (gene signatures, GSs) that contains the transcript compositions of various human tissues and was the first systematic effort to acquire gene expression data. For the construction of BodyMap, cDNA libraries were made, preserving abundance information and histologic resolutions of tissue mRNAs. By sequencing 164,000 randomly selected clones, 88,587 GSs that represent chromosomally coded transcripts have been collected from 51 human organs and tissues. They were clustered into 18,722 independent 3' termini from transcripts, and more than 3000 of these were not found among ESTs assembled in UniGene (Build 75). Assessment of the prevalence of polyadenylation signals and comparison with GenBank cDNAs indicated that there was no significant contamination by internally primed cDNAs or genomic fragments but that there was a relatively high incidence (12%) of alternative polyadenylation sites. We evaluated the sensitivity and resolution of expression information in BodyMap by in silico Northern hybridization and selection of tissue-specific gene probes. BodyMap is a unique resource for estimation of the absolute abundance of transcripts and selection of gene probes for efficient hybridization-based gene expression profiling.

3' Untranslated Regions↗
PubMed2000

Role of Ca2+ mobilization in muscarinic receptor-mediated membrane depolarization in guinea pig ileal smooth muscle cells.

In single smooth muscle cells dispersed from guinea pig ileum, the muscarinic agonist carbachol (CCh) at 2 microM produced an oscillatory or sustained type of depolarization and at 100 microM, the latter type depolarization. Depletion of internal Ca2+ stores blocked the oscillatory response, but not the sustained responses to 2 microM and 100 microM CCh, although their decay after reaching the peak became faster. Blocking voltage-dependent Ca2+ channels (VDCCs) blocked both types of response to 2 microM CCh, but only slowed the initial rising phase of 100 microM CCh responses. Combination of Ca2+ store depletion and VDCC blockade abolished the responses to 2 microM CCh again and decreased those to 100 microM CCh in peak amplitude and persistency. Combination of Ca2+ store depletion with removal of extracellular Ca2+ markedly reduced or abolished the 100 microM CCh responses. The results suggest that muscarinic depolarization of the ileal cells requires Ca2+ mobilization for its generation and persistence; at weak muscarinic stimulation, both Ca2+ entry via VDCCs and Ca2+ release from internal stores may contribute to the Ca2+ mobilization; and under strong muscarinic stimulation, Ca2+ entry pathways resistant to VDCC blockers may also contribute to it.

Animals↗
PubMed2000

Generation of recombinant human large latent transforming growth factor-beta 1 and monoclonal antibodies to it.

Transforming growth factor beta 1 (TGF-beta 1) is a regulator of cell growth and differentiation. It is produced in various of cells and tissues as a biologically latent complex, whose significance is still unknown. We established a Chinese hamster ovary cells that produced recombinant human large latent TGF-beta 1. The growth factor was purified from serum-free conditioned medium of the cell line was purified to apparent homogeneity by four steps of column chromatography. The purified protein gave a single band with the apparent molecular weight of 210,000 on SDS-PAGE, and had four subunits, of 12.5, 40, 53, and 150-190 kDa. These components were identical to TGF-beta 1, the N-terminal remnant of pro-TGF-beta 1, pro-TGF-beta 1, and latent TGF-beta 1 binding protein, respectively. The purified growth factor had biological activity similar to that of the growth factor purified from human platelets. We prepared four monoclonal antibodies by immunization of mice with the recombinant protein. In western blotting, two of the antibodies bound to latent TGF-beta 1 binding protein. The two other antibodies reacted with the N-terminal remnant of pro-TGF-beta 1. Recombinant large latent TGF-beta 1 and its monoclonal antibodies could be used for detailed structural and functional studies of the large latent TGF-beta 1 complex.

Amino Acid Sequence↗
PubMed2000

Radical-capturing reaction of 5,7,3',4'-tetramethylquercetin with the AIBN radical initiator.

In order to clarify the mechanism for the radical-capturing reaction which is initiated at the C3-hydroxyl group of flavonols, 5,7,3',4'-tetramethylquercetin (TMQ) was reacted with the 2,2'-azobis-isobutyronitrile (AIBN) radical initiator in benzene. Six products, one depside and its two hydrolytic products, one nitrile adduct, and two others, were isolated from the reaction mixture, and their structures were determined by instrumental analyses. The quantitative change to the four main products against the reaction time was measured by an HPLC method. The radical-capturing reaction pathway for TMQ with AIBN is proposed from these products and their quantitative changes. The pathway dividing into two clearly reveals that one subpath formed the depside and its hydrolytic products, while the other formed the nitrile adduct. The reactivity of each two sub-path was nearly the same, different from the case of TMQ and the 2,2'-azobis-2,4-dimethylvaleronitrile (AMVN) radical initiator.

Benzene↗