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Y Sakai

Publications and source records attributed to Y Sakai.

At least 469 records · Page 26Linked to original sources
PubMed1995

[Comparison of amplified Mycobacterium Tuberculosis Direct Test (MTD), Amplicor Mycobacteria kit (Amplicor) and PCR method for detection Mycobacterium tuberculosis in clinical specimens].

Accuracy amplified Mycobacterium Tuberculosis Direct Test (MTD), Amplicor Mycobacteria kit (Amplicor) and PCR method routinely used in the University of Tokyo Hospital (J. Clin. Microbiol. 31: 446-450 1991) were evaluated and compared with the same samples. The detection limits of MTD, Amplicor and PCR method (University of Tokyo) were 0.01-0.1 CFU/tube, 0.625 CFU/tube and 0.2 CFU/tube respectively, which were almost the same. These were shown to be at least as sensitive as the conventional culture techniques. The Tokyo Univ. method using radioisotope, takes up to 3 days, on the other hand 2 kits take 4-5 hours. These kits become useful tools for the early and rapid detection of M. tuberculosis in uncultured clinical specimens. But the risk of laboratory contamination and false-positive results remain. These must be further improved.

Bacteriological Techniques↗
PubMed1995

Distribution and properties of fructosyl amino acid oxidase in fungi.

Fructosyl amino acid oxidase, and enzyme that can be used for the determination of glycated proteins in blood samples from diabetic patients, was used to screen cultures in our microorganism culture collection. Fructosyl amino acid oxidase was found only in the strains of four genera of fungi, Aspergillus, Fusarium, Gibberella, and Penicillium and exhibited different substrate specificities against fructosyl valine and N epsilon-fructosyl N alpha-Z-lysine. A fructosyl valine-specific enzyme from Penicillium janthinellum AKU3413 was monomeric (M(r), 49,000), was most active at 35 degrees C and pH 8.0, and had a covalently bound flavin adenine dinucleotide as a prosthetic group.

Amino Acid Oxidoreductases↗
PubMed1995

The Candida boidinii peroxisomal membrane protein Pmp30 has a role in peroxisomal proliferation and is functionally homologous to Pmp27 from Saccharomyces cerevisiae.

The mechanism of peroxisome proliferation is poorly understood. Candida boidinii is a methylotrophic yeast that undergoes rapid and massive peroxisome proliferation and serves as a good model system for this process. Pmp30A and Pmp30B (formerly designated Pmp31 and Pmp32, respectively) are two closely related proteins in a polyploid strain of this yeast that are strongly induced by diverse peroxisome proliferators such as methanol, oleate, and D-alanine. The function of these proteins is not understood. To study this issue, we used a recently described haploid strain (S2) of C. boidinii that can be manipulated genetically. We now report that strain S2 contains a single PMP30 gene very similar in sequence (greater than 93% identity at the DNA level) to PMP30A and PMP30B. When PMP30 was disrupted, cell growth on methanol was greatly inhibited, and cells grown in both methanol and oleate had fewer, larger, and more spherical peroxisomes than wild-type cells. A similar phenotype was recently described for Saccharomyces cerevisiae cultured on oleate in which PMP27, which encodes a protein of related sequence that is important for peroxisome proliferation, was disrupted. To determine whether Pmp27 is a functional homolog of Pmp30, gentle complementation was performed. PMP30A was expressed in the PMP27 disruptant of S. cerevisiae, and PMP27 was expressed in the PMP30 disruptant of C. boidinii S2. Complementation, in terms of both cell growth and organelle size, shape, and number, was successful in both directions, although reversion to a wild-type phenotype was only partial for the PMP30 disruptant. We conclude that these proteins are functional homologs and that both Pmp30 and Pmp27 have a direct role in proliferation and organelle size rather than a role in a specific peroxisomal metabolic pathway of substrate utilization.

Amino Acid Sequence↗
PubMed1995

Intestinal fatty acid binding protein is available for diagnosis of intestinal ischaemia: immunochemical analysis of two patients with ischaemic intestinal diseases.

Mesenteric infarction and other acute ischaemic intestinal diseases are still a challenging diagnostic problem. Based on animal experiments, intestinal fatty acid binding protein (I-FABP), which is uniquely localised to the bowel, has recently been proposed as a new serum marker for intestinal ischaemia. This paper reports on two cases with acute intestinal ischaemic diseases, and the measurement of serum I-FABP by western blot analysis. The concentrations of ordinary serum markers were normal and the bowel necrosis was not diagnosed until surgical exploration. Immunochemical analysis showed that the I-FABP concentrations in the patients' serum samples were high at the time of admission, and that I-FABP was undetectable in the samples obtained after bowel resection and in healthy control subjects. This paper suggests that I-FABP is released into the circulation in the acute phase of intestinal ischaemia and that I-FABP can be used in establishing the diagnosis of ischaemic intestinal diseases.

Acute Disease↗
PubMed1995

Effect of acetylcholine on corticotropin-releasing factor gene expression in the hypothalamic paraventricular nucleus of conscious rats.

To examine the physiological role of cholinergic input in the regulation of CRF neurons in the paraventricular nucleus (PVN) of the hypothalamus, acetylcholine (ACh) was microinjected bilaterally into the dorsolateral border of the PVN of conscious rats. Changes in the levels of POMC messenger RNA (mRNA) in the anterior pituitary, CRF mRNA in hypothalamic tissue containing the PVN, and plasma ACTH were assessed. Plasma ACTH concentrations increased in a dose-dependent manner after ACh injection (1-100 pmol/side), reaching a peak 30 min after ACh injection and returning to baseline within 120 min. The POMC mRNA level in the anterior pituitary and the hypothalamic CRF mRNA level increased in a dose-dependent manner 120 min after ACh (0.1-10 pmol/side) injection. Intracerebroventricular pretreatment with atropine completely abolished the ACh-induced increase in plasma ACTH concentrations, whereas pretreatment with hexamethonium was without significant effect. The intracerebroventricular injection of ACh also increased plasma ACTH concentrations in a dose-dependent manner in conscious rats, but not in pentobarbital-anesthetized animals. Thus, cholinergic hypothalamic input stimulates CRF gene expression in the PVN and CRF secretion into the portal circulation under physiological conditions. The use of conscious animals is essential in elucidating the physiological roles of neurotransmitters and other modulators regulating CRF neurons.

Acetylcholine↗
PubMed1995

Purification and properties of fructosyl lysine oxidase from Fusarium oxysporum S-1F4.

Fructosyl lysine oxidase (FLOD) was examined for its use in the enzymatic measurement of the level of glycated albumin in blood serum. To isolate microorganisms having such an enzyme activity, we used N epsilon-fructosyl N alpha-Z-lysine (epsilon-FL) as a sole nitrogen source in the enrichment culture medium. The isolated fungus, strain S-1F4, showed a high FLOD activity in the cell-free extract and was identified as Fusarium oxysporum. FLOD was purified to an apparent homogeneity on SDS-PAGE. The molecular mass of the subunit was 50 kDa on SDS-PAGE and seemed to exist in a monomeric form. The enzyme had an absorption spectrum characteristic of a flavoprotein and the flavin was found to be covalently bound to the enzyme. The enzyme acted against N epsilon-fructosyl N alpha-Z-lysine and N alpha-fructosyl N epsilon-Z-lysine and showed specificity for fructosyl lysine residues.

Amino Acid Oxidoreductases↗
PubMed1995

Heart failure progression due to secondary organ dysfunction in acute heart failure.

Although the pathophysiology of heart failure progression is important to survival it is not fully understood. In 92 patients with acute heart failure due to myocardial infarction or dilated cardiomyopathy, secondary organ dysfunction was evaluated to determine whether this factor contributed to heart failure progression and death. Forty-one patients had renal dysfunction, hepatic disease or loss of consciousness after the onset of the acute heart failure, and 26 of them (63%) died of progressive heart failure during the follow-up period of 20 months on average. The one-year survival rate was 22%. Although 51 other patients showed the same initial clinical features and cardiac function, they did not develop concurrent organ dysfunction during the course and only 11 (22%, p < 0.001) died of progressive heart failure. The one-year survival rate was 67%. The survival rate decreased in the order of renal dysfunction, hepatic disease and loss of consciousness. Transient low cardiac output of less than 2.2 l/min/m2 was more frequent in patients with organ dysfunction. It is suggested that heart failure progresses, in part, due to organ dysfunction secondary to heart failure and careful treatment to prevent organ dysfunction is important to long term survival.

Acute Disease↗
PubMed1995

[Diagnostic significance of QRST isointegral map in patients with premature ventricular contraction].

Identification of the focus of premature ventricular contraction (PVC) has been reported by various body surface mapping methods: i.e. PVC isopotential map, ventricular activation time map, QRS isointegral map, PVC T wave map, etc. For evaluating the clinical usefulness and diagnostic significance of QRST isointegral map in patients with PVC, 23 patients without apparent underlying heart disease (group N), and 44 patients with dilated cardiomyopathy (group D), were studied. The significant changes in QRST values at maximal points during two activation sequences (basic rhythm and PVC) were detected in group D (N:D = 26.6 +/- 17.6:52.6 +/- 27.0%, p < 0.01), which were frequently directed to the PVC focus and influenced by the short coupling interval (Q-Q interval: 300-390 ms). In conclusion, QRST isointegral map reflecting ventricular gradient may be useful for identifying the presence of underlying heart disease and may correlate with the focus and coupling interval of PVC.

Body Surface Potential Mapping↗
PubMed1995

[Reproducibility of MTD system for detection of Mycobacterium tuberculosis: a cooperative study among six laboratories].

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) is a rapid test for the detection of Mycobacterium tuberculosis, utilizing the rRNA amplification method. For assessing the reliability and reproducibility of the method, a co-operative blind study was conducted among 6 laboratories. Materials for test were sputum and water samples containing known numbers of Mycobacterium bovis BCG or Mycobacterium avium, and samples without bacteria. From three of 6 laboratories, false-positive results were reported for bacteria negative samples, however, the ratio was below 10%; 8.3% (3/36 samples), 5.6% (2/36), and 2.8% (1/36), respectively. It indicates the indispensability of negative controls for sample pretreatment and RNA extraction stages in the routine MTD test. In every laboratory, all the samples with 10(2) BCG in water and 10(4) BCG in sputum were found to be MTD positive. For the sputum samples with 10(2) BCG, positive results with the ratio above 80% were reported from 4 laboratories. These results indicate that the MTD test based on rRNA amplification method is quite useful for the rapid diagnosis of M. tuberculosis infection.

Humans↗
PubMed1995

[QRST isointegral map in dilated cardiomyopathy].

To evaluate the diagnostic usefulness and prognostic significance of QRST isointegral map in dilated cardiomyopathy (DCM), we performed body surface mapping, signal averaged electrocardiogram and thallium-201 myocardial scintigraphy in 41 DCM patients. Late potentials (LP) were detected in 17 patients (41%). QRST isointegral subtraction map (QRST I-sub map: departure map, calculated from 40 normal subjects) showed -2 standard deviation area and departure indices at minimal point (DImin) were calculated in each case. Significant coefficients of correlation were observed between the DImin and root mean square voltage in last 40 ms (r = -0.435, p < 0.001). The abnormal scintigraphic patterns were discriminated into 3 groups: anteroseptal, inferoapical and posterolateral defects, which revealed separate distribution of minimal point in QRST I-sub map: F-G 4, G-H 2 and I-J 4, respectively. These results suggest that QRST isointegral map is useful for detecting the presence of LP (prognostic value) and the location of scintigraphic perfusion defect (diagnostic value) in DCM.

Body Surface Potential Mapping↗
PubMed1995

[Gastrin].

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Gastrins↗
PubMed1994

Structure and chromosomal locus of the mouse gene encoding a cerebellar Purkinje cell-specific helix-loop-helix factor Hes-3.

HES-3 is a cerebellar Purkinje cell-specific helix-loop-helix factor structurally related to the products of the Drosophila hairy and Enhancer of split genes. Here, we report the nucleotide sequence and chromosomal locus of the mouse Hes-3 gene. This gene consists of four exons and the exon-intron boundaries are well conserved when compared with those of the mouse Hes-1 and Drosophila hairy genes. Southern blot and interspecies backcross analyses show that the mouse Hes-3 gene is a single-copy gene and is located around position 80 on chromosome 4. Further analysis indicates that this locus is close to the Hes-5 locus, which is different from the Hes-1 locus (position 26 on chromosome 16). These results suggest that the Hes-3 and Hes-5 genes may be clustered on chromosome 4 while the Hes-1 gene is not.

Amino Acid Sequence↗
PubMed1994

Colocalization of prolyl endopeptidase and amyloid beta-peptide in brains of senescence-accelerated mouse.

Prolyl endopeptidase-like immunoreactivity (PEP-LI) was detected and compared with amyloid beta-peptide-like immunoreactivity (A beta-LI) in the brains of senescence-accelerated mouse (SAM). Granular structures of PEP-LI in the hippocampus appeared progressively, and age- and strain-dependently to form deposits which distributed morphologically similar and closely to those of A beta-LI. These results suggest that PEP has functional relevance to amyloidgenesis in brains of SAM.

Aging↗
PubMed1994

Molecular cloning and characterization of the promoter for human type-1 angiotensin II receptor gene.

We isolated a genomic clone containing 2558 bp of the 5'-flanking region and 217 bp of the first exon for the human type-1 angiotensin II receptor (AT1) gene. Primer extension and RNAase protection analyses identified a transcriptional start site (+1) at 39 and 114 bp downstream of putative TATA and GC boxes, respectively. Chimeras containing 2.6 kbp(-2558 to +79) of the 5'-flanking region and chloramphenicol acetyltransferase (CAT) gene expressed a significant CAT activity when transfected into bovine aortic smooth muscle cells (BASMC), but not the cells which had no detectable AT1 receptors, such as HeLa cells and primary cultured human skin fibroblasts. Deletion of the 5'-flanking region up to position -114 resulted in more than 20-fold increase of the reporter activity in BASMC, suggesting the presence of negatively regulating element(s) in the upstream promoter region. These results indicate that we have cloned a functional promoter for the human AT1 receptor gene.

Base Sequence↗