PubMed Health⌕ Search

Biomedical subjects

H Yanase

Publications and source records attributed to H Yanase.

At least 55 records · Page 3Linked to original sources
PubMed1996

Cloning and sequence analysis of the gene encoding 3-hexulose-6-phosphate synthase from the methylotrophic bacterium, Methylomonas aminofaciens 77a, and its expression in Escherichia coli.

A DNA fragment of 550 bp was specifically amplified by PCR with primers based on the N-terminal sequence of the purified 3-hexulose-6-phosphate synthase from Methylomonas aminofaciens 77a and on that of a lysyl endopeptidase-derived peptide. Using this PCR product as a probe, a gene coding for 3-hexulose-6-phosphate synthase in M. aminofaciens 77a chromosomal DNA was cloned in Escherichia coli JM109. Sequencing analysis revealed that the gene encoding 3-hexulose-6-phosphate synthase contained a 624-bp open reading frame, encoding a protein composed of 208 amino acid residues with a calculated relative molecular mass of 21,224.

Aldehyde-Lyases↗
PubMed1996

A study of the sedative effect of home-administered oral diazepam for the dental treatment of children.

This study investigated the effects of oral diazepam administered at home to fearful child patients prior to dental treatment. Twenty-five healthy, uncooperative children, mean age 3 years 8 months (+/- 1 year 3 months), requiring at least three visits for the treatment of dental caries, were studied. Each child's behaviour was assessed during three treatment sessions: (i) control, with no diazepam or placebo; (ii) with diazepam; and (iii) with a placebo. Each child acted as his/her own control, being initially assigned to the control session. Subsequently each was randomly assigned to receive either diazepam or placebo for the second session and the other for the third session. The diazepam and placebo were administered by the parents at home approximately 60 minutes before treatment. Each patient's behaviour was assessed on a scale of 1 (definitely positive) to 4 (definitely negative) by two calibrated examiners who were blind to the medications given and independent of the treatment. Vital signs were monitored at 5-minute intervals. Behaviour was significantly better with diazepam than with the placebo or with neither. No significant differences were observed between the placebo and control sessions. At no time were any adverse effects noted, such as vomiting or respiratory depression. It was concluded that oral administration of 0.3 mg/kg diazepam at home by the parent is an effective and safe technique for preoperative sedation of fearful child patients.

Administration, Oral↗
PubMed1996

Ibudilast reduces intracellular calcium elevation induced by in vitro ischaemia in gerbil hippocampal slices.

1. A microfluorometry was carried out to investigate the effect of 3-isobutyryl-2-isopropylpyrazolo[1,5-a]pyridine (ibudilast) on changes in levels of intracellular calcium concentration ([Ca2+]i) induced by in vitro ischaemia in the CA1 field of gerbil hippocampal slices. 2. When slices, loaded with a calcium ion sensitive dye (rhod-2) were exposed to a glucose-free physiological medium equilibrated with a 95% N2/5% CO2 gas mixture (standard in vitro ischaemia), a large [Ca2+]i elevation was detected approximately 5 min after the beginning of in vitro ischaemia. 3. When slices were perfused with the in vitro ischaemic medium containing 43 mumol/L ibudilast, a [Ca2+]i elevation was still observed; however, the extent of the increase in [Ca2+]i was significantly depressed in all subregions of the hippocampal slices. 4. The extent of this inhibitory effect of ibudilast on the in vitro ischaemia-induced [Ca2+]i elevation was in a similar range as those of Ca2+ blockers, including (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cycloheptan-5,10-imine maleate (MK-801), flunarizine and dantrolene. 5. Similar [Ca2+]i increases in the CA1 field were induced by a Ca(2+)-free in vitro ischaemia, a high concentration of KCl or by specific agonists for glutamate receptor subtypes (N-methyl-D-aspartate (NMDA), (s)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and kainate); these increases were also depressed with 43 mumol/L ibudilast present in the perfusion medium. 6. These results indicate that ibudilast may act by depressing the Ca2+ accumulation during and shortly after ischaemia, a possible pharmacological action of ibudilast that leads to the amelioration of ischaemic injury in the central nervous system.

Analysis of Variance↗
PubMed1996

Cloning of the aldehyde reductase gene from a red yeast, Sporobolomyces salmonicolor, and characterization of the gene and its product.

An NADPH-dependent aldehyde reductase (ALR) isolated from a red yeast, Sporobolomyces salmonicolor, catalyzes the reduction of a variety of carbonyl compounds. To investigate its primary structure, we cloned and sequenced the cDNA coding for ALR. The aldehyde reductase gene (ALR) comprises 969 bp and encodes a polypeptide of 35,232 Da. The deduced amino acid sequence showed a high degree of similarity to other members of the aldo-keto reductase superfamily. Analysis of the genomic DNA sequence indicated that the ALR gene was interrupted by six introns (two in the 5' noncoding region and four in the coding region). Southern hybridization analysis of the genomic DNA from S. salmonicolor indicated that there was one copy of the gene. The ALR gene was expressed in Escherichia coli under the control of the tac promoter. The enzyme expressed in E. coli was purified to homogeneity and showed the same catalytic properties as did the enzyme from S. salmonicolor.

Alcohol Oxidoreductases↗
PubMed1995

A recombinant human hemoglobin with asparagine-102(beta) substituted by alanine has a limiting low oxygen affinity, reduced marginally by chloride.

A recombinant (r) mutant hemoglobin (Hb) with Asn-102(beta) replaced by an Ala (N102A(beta)) has been prepared by PCR amplification of a mutagenic DNA fragment and expression of the recombinant protein in yeast. The side chain of Asn-102(beta) is part of an important region of the alpha 1 beta 2 interface that undergoes large structural changes in the transition between the deoxy and oxy conformations. Three natural mutant Hbs with neutral substitutions of Thr, Ser, or Tyr at this site have low oxygen affinities because a hydrogen bond between Asn-102(beta) and Asp-94(alpha) in normal HbA was considered to be absent in these mutants, thereby destabilizing the oxy conformation in favor of the deoxy conformation. This proposal has been tested by expression of an rHb containing alanine at position 102(beta); alanine was chosen because its methyl side chain cannot participate in hydrogen bond formation, yet it is small enough not to disrupt the subunit interface. The nature of the desired replacement was established by sequencing the entire mutated beta-globin gene as well as the tryptic peptide containing the substitution. Further characterization by SDS-PAGE, isoelectric focusing, HPLC analysis, mass spectrometry, amino acid analysis, and sequencing of the mutant tryptic peptide confirmed the purity of the rHb. Its oxygen binding curve (2.4 mM in heme) in the absence of chloride showed that it had a very low oxygen affinity with a P50 of 42 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine↗
PubMed1995

In vitro ischemia-induced intracellular Ca2+ elevation in cerebellar slices: a comparative study with the values found in hippocampal slices.

Changes in levels of intracellular calcium ion ([Ca2+]i) induced by in vitro ischemic conditions in gerbil cerebellar and hippocampal slices were investigated using a calcium imaging system and electron microscopy. When the cerebellar slice was perfused with a glucose-free physiological medium equilibrated with a 95% N2/5% CO2 gas mixture (in vitro ischemic medium), a large [Ca2+]i elevation was region-specifically induced in the molecular layer of the cerebellar cortex (a dendritic field of Purkinje cells). When the hippocampal slice was perfused with in vitro ischemic medium, a large [Ca2+]i elevation was region-specifically induced in CA1 field of the hippocampal slices. Electron microscopic examinations showed that the large [Ca2+]i elevations occurred in Purkinje cells and CA1 pyramidal neurons. To isolate Ca2+ release from intracellular Ca2+ store sites, the slices were perfused with Ca(2+)-free in vitro ischemic medium. The increases in [Ca2+]i in both cerebellar and hippocampal slices were significantly lower than those observed in the slices perfused with the Ca(2+)-containing in vitro ischemic medium. However, the suppression of the [Ca2+]i elevation in the molecular layer of the cerebellar slices was smaller than that in the CA1 field of the hippocampal slices. These results reinforce the hypothesis that calcium plays a pivotal role in the development of ischemia-induced neuronal death, and suggest that Ca2+ release from intracellular Ca2+ store sites may play an important role in the ischemia-induced [Ca2+]i elevation in Purkinje cells.

Animals↗
PubMed1995

Sclerosing stromal tumour in a cow.

A case of sclerosing stromal tumour in an 8-year-old cow is described. The left ovary was entirely replaced by neoplastic tissue, whose features were pseudolobulation of cellular areas, intercellular oedema and calcified plaques. The neoplastic cells varied in morphology and were similar to ovarian stromal cells, theca cells or lutein cells. Immunohistochemically, S-100 protein, oestradiol and testosterone were detected in theca-like or luteinized cells, some of which had ultrastructural features suggestive of steroid hormone synthesis. In contrast, desmin and actin characterized slender spindle cells. This is the first report of a sclerosing stromal tumour in cattle.

Animals↗
PubMed1995

Properties of poly(3-hydroxybutyrate) depolymerase from a marine bacterium, Alcaligenes faecalis AE122.

Alcaligenes faecalis AE122 that used poly(3-hydroxybutyrate) (PHB) as a sole source of carbon was newly isolated from a coastal seawater sample. The strain required seawater for growth on PHB as well as in a nutrient broth, in which seawater could be replaced by an appropriate concentration of NaCl. PHB depolymerase was purified to homogeneity from the culture supernatant of A. faecalis AE122 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme consisted of a monomer subunit with a molecular mass of 95.5 kDa. The N-terminal amino acid sequence was GAWQNNLAGGFNKV. The dimeric and trimeric esters of 3-hydroxybutyrate were the main hydrolysis products of the purified enzyme. The enzyme was most active at pH 9.0 and 55 degrees C and was inhibited by phenylmethylsulfonyl fluoride. Several cations in seawater greatly enhanced the enzyme activity.

Alcaligenes↗
PubMed1995

Cloning, sequence analysis, and expression of the gene encoding formaldehyde dismutase from Pseudomonas putida F61.

The gene (fdm) coding for formaldehyde dismutase (EC 1.2.99.4) from a genomic library of formaldehyde-tolerant Pseudomonas putida F61 was cloned and expressed in Escherichia coli. The nucleotides of the cloned DNA were sequenced; they included a single open reading frame of 1200 base pairs, coding for a putative protein with a molecular weight of 42,848. Sequencing of the first 20 N-terminal amino acid residues and of an internal part of the enzyme purified from P. putida F61 established the identity and the start codon of fdm. Comparison of the amino acid sequence predicted from fdm with that of alcohol dehydrogenase from horse liver suggested a putative pyridine-dinucleotide-binding domain in fdm, and also potential ligands for the catalytic domain and the second zinc atom-folding domain. fdm seemed to be expressed in E. coli under control of the promoter of fdm; there was an E. coli promoter-like sequence upstream from the gene. The enzyme expressed in E. coli was purified to homogeneity. The molecular weight and the sequence of the first 20 N-terminal amino acid residues were identical with those of P. putida formaldehyde dismutase. Each subunit contained 1 mol of NAD(H) and 2 mol of zinc per mol of protein. The enzyme produced in E. coli catalyzed the dismutation of formaldehyde to form methanol and formic acid at the ratio of 1:1 in the absence of the exogenous electron acceptor, NAD(H).

Alcohol Dehydrogenase↗
PubMed1995

Cloning and characterization of Zymomonas mobilis genes encoding extracellular levansucrase and invertase.

The genes encoding the extracellular levansucrase and invertase of Zymomonas mobilis have been cloned and sequenced. The levansucrase gene, sucZE2, spans 1269 bp and encodes an M(r) 46,790 polypeptide, and the invertase gene, sucZE3, is of 1239 bp and encodes an M(r) 46,110 polypeptide. The 5'-terminal sequences of both genes corresponded to the N-terminal amino acid sequences of the secreted levansucrase and invertase, implying that the secretion of both enzymes does not involve proteolytic processing of the N-terminals. Both enzyme molecules appear to carry no typical N-terminal secretion signal. Significant homology between sucZE2 and sucZE3 was observed, but both genes showed no homology to the gene encoding an intracellular invertase coexisting in Z. mobilis. Two genes, sucZE2 and sucZE3, are possibly placed in an operon because the expression of two genes were simultaneously controlled by the regulator gene zliE, previously identified.

Amino Acid Sequence↗
PubMed1994

Properties of a recombinant human hemoglobin with aspartic acid 99(beta), an important intersubunit contact site, substituted by lysine.

Site-directed mutagenesis of an important subunit contact site, Asp-99(beta), by a Lys residue (D99K(beta)) was proven by sequencing the entire beta-globin gene and the mutant tryptic peptide. Oxygen equilibrium curves of the mutant hemoglobin (Hb) (2-15 mM in heme) indicated that it had an increased oxygen affinity and a lowered but significant amount of cooperativity compared to native HbA. However, in contrast to normal HbA, oxygen binding of the recombinant mutant Hb was only marginally affected by the allosteric regulators 2,3-diphosphoglycerate or inositol hexaphosphate and was not at all responsive to chloride. The efficiency of oxygen binding by HbA in the presence of allosteric regulators was limited by the mutant Hb. At concentrations of 0.2 mM or lower in heme, the mutant D99K(beta) Hb was predominantly a dimer as demonstrated by gel filtration, haptoglobin binding, fluorescence quenching, and light scattering. The purified dimeric recombinant Hb mutant exists in 2 forms that are separable on isoelectric focusing by about 0.1 pH unit, in contrast to tetrameric hemoglobin, which shows 1 band. These mutant forms, which were present in a ratio of 60:40, had the same masses for their heme and globin moieties as determined by mass spectrometry. The elution positions of the alpha- and beta-globin subunits on HPLC were identical. Circular dichroism studies showed that one form of the mutant Hb had a negative ellipticity at 410 nm and the other had positive ellipticity at this wavelength. The findings suggest that the 2 D99K(beta) recombinant mutant forms have differences in their heme-protein environments.

Amino Acid Sequence↗
PubMed1994

Clear cell adenocarcinoma of the vagina in a young female, treated by combination chemotherapy (local and systemic chemotherapy), complicated with chromosomal abnormality.

Although cancer of the vagina, a rare form of genital cancer, is usually squamous cell carcinoma in women over the age of 50 years, vaginal clear cell adenocarcinomas (CCA) are exceedingly rare. The pathogenesis of clear cell adenocarcinoma is uncertain, but as a clinical entity, it is most commonly associated with diethylstilbestrol exposure in utero. We report a rare case of primary vaginal CCA in a 17-year-old female who was not exposed to diethylstilbesterol in utero. The case, which was complicated with chromosomal abnormality, was treated with combination chemotherapy. To our knowledge, this is the first reported case of vaginal CCA in a woman with chromosomal abnormality and bicornate uterus.

Adenocarcinoma, Clear Cell↗
PubMed1994

Properties of the 'neutral zone' explain polarity of retinal spreading depression.

Retinal spreading depression was evoked using low Cl- Ringer's solution and the concomitant field potentials (spreading depression potential; SDP) were recorded. The polarity of the transretinally recorded SDPs was not consistent among animal species. The SDPs recorded from carp and frog were receptor side negative, while chick and cat induced receptor side positive SDPs. According to the K+ hypothesis, the retinal SDP is generated by Müller cells responding to an increase in the extracellular K+ concentration in the inner plexiform layer. In order to clarify the relationship between the K+ increase and the polarity of the SDP, a high-K+ solution was injected at various retinal depths and the evoked potential was recorded transretinally. The neutral zone within the retina, where a change in the extracellular K+ concentration produces no net potential difference, was revealed to be near the proximal end of the retina in carp and frog, while it was located distal to the inner plexiform layer in the chick and cat. These results support the Müller cell K+ hypothesis and explain the polarity of SDPs. We conclude that the concept of the neutral zone is valuable for the investigation of the mechanism and polarity of transretinal field potentials.

Animals↗
PubMed1994

Changes in intracellular Ca2+ and energy levels during in vitro ischemia in the gerbil hippocampal slice.

The time course of the decline in energy levels during an in vitro ischemia-like condition was compared with changes in intracellular Ca2+ concentration ([Ca2+]i) in subregions of the gerbil hippocampal slice [CA1, CA3, and the inner and outer portions of the dentate gyrus (DG)]. Hippocampal transverse slices were loaded with a fluorescent indicator, rhod-2. During the on-line monitoring of [Ca2+]i, the slices were perfused with an in vitro ischemia-like medium (33 degrees C). The slices were collected at several experimental time points, frozen, dried, and dissected into subregions. The contents of adenine nucleotides (ATP, ADP, and AMP) and phosphocreatine (PCr) were measured by HPLC methods. Region-specific and acute [Ca2+]i elevations were observed in CA1 approximately 4 min after onset of the in vitro ischemia-like condition and also in the inner portion of the DG with a delay of 10-40 s. The change in ATP levels was related to the increase in [Ca2+]i. ATP levels in all subregions gradually decreased before the acute [Ca2+]i elevation. Concomitant with the acute [Ca2+]i elevation in CA1 and the inner portion of the DG, ATP levels in the subregions rapidly decreased, whereas declines in levels of high-energy-charge phosphates were gradual in CA3 and the outer portion of the DG, in which the remarkable [Ca2+]i elevation was not observed. These results suggest that ATP depletion observed in CA1 and the inner portion of the DG is due to the region-specific increase in [Ca2+]i, which activates a Ca(2+)-ATP-driven pump and produces a subsequent fall in neuronal ATP content.

Adenine Nucleotides↗
PubMed1994

Autologous blood transfusion using recombinant human erythropoietin in radical hysterectomy.

The possibility of serious complications of infection and GVHD and adverse prognosis in cancer patients resulting from homologous blood transfusions has been reported. We used recombinant human erythropoietin (rHuEPO) in autologous blood transfusions for radical hysterectomies to avoid the risks associated with transfusions. rHuEPO efficacy, stability and influence on hemodynamics were investigated. All patients were able to donate 1,200 ml of autologous blood prior to surgery, and anemia did not result despite phlebotomy three times each week. Elevation in Hb concentration was calculated at 0.78 +/- 0.37 g/dl over the first 7 days, and 2.12 +/- 0.35 g/dl over the first 14 days. No adverse side effects were observed in any patient. The serum EPO level was measured by RIA, and compared to the homologous blood transfusion group. rHuEPO did not influence postoperative EPO secretion. Autologous blood transfusion with rHuEPO in radical hysterectomy was extremely effective in mitigating the risks associated with homologous blood transfusions.

Blood Transfusion, Autologous↗
PubMed1994

Cloning and characterization of a pair of genes that stimulate the production and secretion of Zymomonas mobilis extracellular levansucrase and invertase.

A 1.7-kb DNA fragment cloned from Zymomonas mobilis genomic DNA complemented the inability to grow on sucrose of a Suc- mutant of Z. mobilis that was deficient in the production of both extracellular levansucrase and invertase. Analysis of the nucleotide sequence of the fragment found two open reading frames (ORFs), both of which did not correspond to the structural gene for the levansucrase or the invertase. By subcloning each ORF into two different Suc- mutants of Z. mobilis, it has been found that the first ORF (gene zliE) activates the production of the extracellular levansucrase and invertase, and the second ORF (gene zliS) stimulates the secretion of the two enzymes. Gene zliS might contribute to the secretion of proteins having no signal peptide. The expression of zliE and zliS seemed to be under the control of the same promoter.

Amino Acid Sequence↗
PubMed1994

The sedative effects of intranasal midazolam administration in the dental treatment of patients with mental disabilities. Part 2: optimal concentration of intranasal midazolam.

In a previous paper, we reported on the effect of a 0.2 mg/kg dose of midazolam, administered intranasally, prior to performing various restorative dental procedures on a group of mentally disabled patients under local anesthesia and nitrous oxide/oxygen analgesia. The purpose of this study was to compare the clinical and possible adverse effect of doses of 0.2 mg/kg and 0.3 mg/kg midazolam, administered intranasally, and to determine the most appropriate concentration for the drug when administered by this route. Patients were assessed by a behavioral test which consisted of a scale from 1-7 with 3 ranges: markedly effective (1-3), effective (4-5) or ineffective (6-7). Forty-three mentally handicapped patients, aged 5 to 20 years, all of whom had previously exhibited highly combative and resistant behavior toward dental treatment under local anesthesia, were stratified by age and randomly assigned in a double blind manner to two groups, receiving either 0.2 mg/kg or 0.3 mg/kg midazolam administered intranasally. Group 1, consisting of 22 patients, average age 11 years 8 months, received 0.2 mg/kg. Group 2 consisted of 21 patients, average age 13 years 8 months, each of whom was administered 0.3 mg/kg intranasal midazolam. Only patients assessed as ASA anesthesia status I or II were admitted to the study. Subsequent to intranasal administration of midazolam, no patient rejected the nasal mask nor refused to inhale nitrous oxide/oxygen. The induction of nitrous oxide/oxygen sedation and oral examination were effected smoothly in every case in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗