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Y Kaneko

Publications and source records attributed to Y Kaneko.

At least 55 records · Page 3Linked to original sources
PubMed2001

Dual-specificity protein phosphatase Yvh1p, which is required for vegetative growth and sporulation, interacts with yeast pescadillo homolog in Saccharomyces cerevisiae.

The Saccharomyces cerevisiae dual-specificity protein phosphatase Yvh1p, identified as vaccinia VH1 homolog, regulates cell growth, sporulation, and glycogen accumulation. Transcription of YVH1 is induced by lowering temperature and nitrogen starvation. Using the yeast two-hybrid system, we searched for Yvh1p-interacting proteins, including substrates and regulatory subunits of Yvh1p. Two clones were identified encoding a segment of YPH1 (yeast pescadillo homolog), which is essential for cell cycle progression in yeast. Deletion analysis revealed that the catalytic domain of Yvh1p and the BRCT domain of Yph1p are sufficient for this interaction. We found that the multicopy of YPH1 not only suppressed slow growth but also decreased IME2 expression in the yvh1 disruptant. These observations indicate that Yph1p plays a role in sporulation in addition to cell cycle progression, and is a candidate for a substrate or a regulatory subunit of Yvh1p.

Blotting, Northern↗
PubMed2001

Mutations/deletions of the WT1 gene, loss of heterozygosity on chromosome arms 11p and 11q, chromosome ploidy and histology in Wilms' tumors in Japan.

Incidence rates of Wilms' tumor (WT) markedly differ in East Asian and Caucasian children. In the present study, we examined WT1 deletions/mutations and loss of heterozygosity (LOH) on 11p and 11q in a large number of WTs and compared our findings with those from 4 series of Caucasian WTs. Incidence rates of the subtle WT1 mutation in 3 of the 5 series of sporadic and unilateral WTs including ours were 4.3-6.2% and similar. However, gross homozygous WT1 deletion was more frequent in our series than in some others. In addition, our series tended to show a higher incidence of LOH limited to 11p13 and a lower incidence of LOH including 11p15 than the Caucasian one. These findings indicate some genetic differences in WT between the 2 regions. One of the 4 Caucasian series reported a correlation of germinal WT1 mutation with the predominantly stromal histology. The present study not only confirms the correlation of germinal WT1 deletion/mutation with predominant stromal histology but also establishes a correlation with somatic WT1 deletion/mutations with predominant stromal histology. While WTs with WT1 abnormalities usually showed pseudodiploidy and predominant stromal histology, those without WT1 abnormalities showed various chromosome numbers and histologic subtypes.

Alleles↗
PubMed2001

Amphibian DNases I are characterized by a C-terminal end with a unique, cysteine-rich stretch and by the insertion of a serine residue into the Ca2+-binding site.

We purified four amphibian deoxyribonucleases I from the pancreases of one toad, two frog and one newt species, by using three different column chromatography methods in sequence. Each of the purified enzymes had a molecular mass of approx. 40 kDa and an optimal pH for activity of approx. 8.0. These values were significantly greater than those for other vertebrate DNases I. The full-length cDNA encoding each amphibian DNase I was constructed from the total RNA of the pancreas by using rapid amplification of cDNA ends. Nucleotide sequence analyses revealed two structural characteristics unique to amphibian DNases I: a stretch of approx. 70 amino acids with a high cysteine content (approx. 15%) in the C-terminal region, and the insertion of a serine residue at position 205 (in a domain containing an essential Ca2+-binding site). Expression analysis of a series of mutant constructs indicated that both of these structures are essential in generating the active form of the enzyme. 'DNase I signature sequences', which are well conserved in other vertebrate DNases I, could not be found in any of the amphibian DNases I tested, whereas a 'somatomedin B motif' was identified in the Cys-rich stretches of all four. Although DNase I has so far been considered to be a secretory glycoprotein, amphibian DNase I seems to be non-glycosylated. These structural findings indicate strongly that amphibian DNases I are situated in a unique position on the phylogenetic tree of the DNase I family.

Amino Acid Sequence↗
PubMed2001

Transplantation of adult rat hippocampus-derived neural stem cells into retina injured by transient ischemia.

Neural stem cells are capable of differentiating along multiple central nervous system cell-type lineages, and their use as graft material has provided new strategies for the treatment of neuronal damage. We transplanted adult rat hippocampus-derived neural stem cells into eyes of adult rats that underwent ischemia-reperfusion injury. As control, the cells were also injected into normal rats eyes without ischemic insult. The rats were sacrificed at 1, 2, 4, and 8 weeks, and the eyes were examined histochemically. In eyes with the insult, the transplanted cells were well integrated into the host retinas and expressed Map2ab. In the control, none of the cells migrated into the retina. These results suggest that neural stem cells may be used as donor cells for transplantation to repair ischemic-injured retina.

Animals↗
PubMed2001

Molecular, biochemical and immunological analyses of porcine pancreatic DNase I.

Deoxyribonuclease I (DNase I) was purified 26500-fold in 39% yield from porcine pancreas to electrophoretic homogeneity using three-step column chromatography. The purified enzyme was inhibited by an antibody specific to the purified enzyme but not by G-actin. A 1303 bp cDNA encoding porcine DNase I was constructed from total RNA from porcine small intestine using a rapid amplification of cDNA ends method, followed by sequencing. Mature porcine DNase I protein was found to consist of 262 amino acids. Unlike all other mammalian DNase I enzymes that are inhibited by G-actin, porcine DNase I has H65 and S114 instead of Y65 and A114, which presumably results in the lack of inhibition. Porcine DNase I was more sensitive to low pH than rat or bovine enzymes. Compared with their primary structures, the amino acid at position 110 was N in porcine enzyme, but S in rat and bovine enzymes. A porcine mutant enzyme in which N was substituted by S alone at position 110 (N110S) became resistant to low pH to a similar extent as the rat and bovine enzymes.

Amino Acid Sequence↗
PubMed2001

Expression pattern of a newt Notch homologue in regenerating newt retina.

We isolated part of a newt Notch homologue, N-Notch, from regenerating newt retina. The spatio-temporal pattern of N-Notch expression was studied by in situ hybridization at different stages of newt retinal regeneration. Proliferating cells were confirmed by the injection of bromodeoxyuridine (BrdU). In the early stage of regeneration, when the retina was one to two cells thick, all proliferating retinal progenitors expressed N-Notch. As the thickness of the retina increased with regeneration, N-Notch expression decreased in BrdU-positive cells on the vitreal side of the retina. Subsequently, presumptive retinal ganglion cells that were BrdU-negative cells appeared at the vitreal edge of the regenerating retina. These differentiating cells did not express N-Notch. Later, N-Notch expression decreased in the BrdU-positive cells on the scleral surface of the retina. Subsequently, presumptive photoreceptor cells that were BrdU-negative cells appeared in this region. These differentiating cells also did not express N-Notch. The proliferating retinal progenitors ceased expressing N-Notch and then stopped dividing during the differentiation of ganglion cells and photoreceptor cells. It was found that retinal regeneration involves the expression of an important developmental signaling molecule, Notch, in retinal progenitors and the expression of Notch ceased as cell differentiation proceeded during retinal regeneration.

Amino Acid Sequence↗
PubMed2001

Tissue-specific in vivo inhibition of DNase I gene expression by somatostatin.

Administration of somatostatin to rats induced a transient reduction of serum levels of deoxyribonuclease I (DNase I) activity in a dose-dependent manner, followed by a substantial decrease of DNase I activity in the lower gut. Activity in the parotid gland, liver, and kidney did not change. Real-time PCR analysis of the DNase I gene transcript in ileum indicated that the decrease was due to down-regulation of gene expression. Based on these responses, rat tissues expressing DNase I could be classified into two types, somatostatin-sensitive and somatostatin-resistant, and the level of DNase I activity in the lower gut seems to be controlled by somatostatin.

Animals↗
PubMed2001

Uncoupling protein 3 and peroxisome proliferator-activated receptor gamma2 contribute to obesity and diabetes in palauans.

We examined the genetic contribution of single nucleotide polymorphisms (SNPs) of the energy metabolism-related genes, including beta 3 adrenergic receptor (beta3AR), apolipoprotein E (apo-E), promoter of uncoupling protein 3 (UCP3-p), peroxisome proliferator-activated receptor gamma 2 (PPARgamma2) and leptin receptor (LEPR) to metabolic disorders, in 118 inhabitants of Palau. The data were statistically analyzed and ethnically compared to correlate SNPs and their metabolic parameters. UCP3-p (P < 0.01) and PPARgamma2 (p = 0.05) correlated with plasma HbA1c, and UCP3-p correlated with fasting blood glucose (P < 0.01) in males, but not in females. UCP3-p correlated with body fat (%) (P < 0.01) in females, but not in males. Plasma leptin levels and apo-E were correlated in both groups. The frequency of SNPs for PPARgamma2, LEPR, and UCP3-p are significantly different between Palauans and Caucasians.

Adipose Tissue↗
PubMed2001

Genetic analysis of p73 localized at chromosome 1p36.3 in primary neuroblastomas.

BACKGROUND: Human p73, a novel homolog of p53, has recently been cloned and mapped at chromosome 1p36.3, the locus for putative tumor suppressor gene(s) of neuroblastoma (NBL) and other cancers. p73, like p53, inhibits growth and induces apoptosis in neuroblastoma and osteosarcoma cell lines. PROCEDURE: To test the hypothesis that p73 is a NBL suppressor gene, we examined expression, allelo-typing, and mutation of the p73 gene in primary human neuroblastomas. Loss of heterozygosity (LOH) for p73 was performed in 272 primary NBLs using a CT repeat polymorphic marker, which we found in intron 9 of the p73 gene. RESULTS: p73 LOH was observed in 28 out of 151 (19%) informative cases. The high frequency of p73 LOH was significantly associated with sporadic neuroblastomas (P< 0.001), MYCN amplification (P< 0.001), and advanced stages (P< 0.05). Mutational analyses by PCR-SSCP (single strand conformation polymorphism) revealed two mis-sense mutations in 140 NBLs, one somatic and one germline. CONCLUSION: Thus, the present results have shown that mutation of p73 is infrequent in NBLs, although the p73 locus is frequently lost in advanced stage tumors. These suggest that p73 may not be a tumor suppressor in the classic Knudson manner.

Amino Acid Substitution↗
PubMed2001

Hemolysis after mitral valve replacement with mechanical valve prostheses.

OBJECTIVE: We evaluated effects of type, size, and orientation of mechanical mitral valve prostheses on hemolysis. METHODS: Subjects were 84 patients who had undergone mitral valve replacement. Lactate dehydrogenase was mainly used as a marker of hemolysis and was measured before surgery, 1 month after surgery, and in the late postoperative period. RESULTS: Valves used included 16 Medtronic-Hall, 32 St. Jude Medical, and 36 CarboMedics valves. Medtronic-Hall valves caused less hemolysis than St. Jude Medical or CarboMedics valves in the late postoperative period. This resulted because hemolysis due to Medtronic-Hall valves was more severe 1 month after surgery than in the late postoperative period and because hemolysis due to St. Jude Medical or CarboMedics valves was more severe in the late postoperative period than 1 month after surgery. One reason for this finding is that cardiac output was greater in the late postoperative period than 1 month after surgery, making regurgitation through the pivots of bileaflet valves more severe. The orifice area and the orientation of prostheses did not affect hemolysis. CONCLUSION: St. Jude Medical or CarboMedics valves caused more severe hemolysis than Medtronic-Hall valves in the late postoperative period.

Aged↗
PubMed2001

Spider silk has an ice nucleation activity.

Several ice nucleating substances have been identified, which exist in vivo or can be extracted from biological materials. Spider silk, which has a strong ability for water condensation, has also been found to possess an ice nucleation activity. The freezing temperature of water droplets was higher in the presence than in the absence of spider silk. Moreover, by means of environmental scanning electron microscopy, it was observed that the activity is not due to foreign matter attached to the silk but to the silk fibroin itself.

Animals↗
PubMed2001

A ruptured dissecting aneurysm of the vertebral artery: comparison of angiographic and histological findings.

We present autopsy findings in a patient with a dissecting aneurysm of the vertebral artery causing subarachnoid haemorrhage. We sectioned the artery longitudinally and compared it with the angiogram, which showed the "pearl-and-string". Histological examination showed a pseudoaneurysm covered by adventitia alone, forming the "pearl". Internal elastic lamina and media were destroyed, and haematoma extended in the subadventitial space of the wall of the pseudoaneurysm. Media thickened by haematoma caused the "string", narrowing the parent artery. Alcian blue staining showed that stratified internal elastic lamina in the aneurysm and the parent artery, had undergone marked mucoid degeneration, which may have been responsible for the dissection.

Aneurysm, Ruptured↗
PubMed2001

HO gene polymorphism in Saccharomyces industrial yeasts and application of novel HO genes to convert homothallism to heterothallism in combination with the mating-type detection cassette.

Southern blot analysis of industrial yeasts showed that all top-fermenting yeasts, distiller's yeasts and a proportion of wine yeasts tested in the present study produced a hybridization signal (approximately 7 kb), corresponding to a Saccharomyces cerevisiae-type HO gene (Sc-HO). It also showed that bottom-fermenting yeasts gave rise to 7-kb and 4-kb hybridization signals, corresponding to the Sc-HO gene and the lager yeast HO gene (Lg-HO), respectively. Two wine yeasts produced a 4-kb hybridization signal, corresponding to Lg-HO; and one wine yeast produced 2.5-kb and 1.5-kb hybridization bands, corresponding to a S. uvarum-type HO gene (Uv-HO). Partial nucleotide sequences of HO genes amplified from these wine yeasts perfectly matched those of Lg-HO and Uv-HO, respectively. HO disruption vectors were constructed by inserting a dominant selective marker PGK1p-neo and the mating-type detection cassette MFalpha1p-PHO5 within the Lg-HO or Uv-HO gene. From transformants carrying a single-disrupted ho gene, mating-competent progenies were easily obtained through meiosis. Moreover, mating-competent derivatives appearing at very low frequency could be obtained from a double-disrupted ho transformant without meiosis (even from a wine yeast lacking sporulation ability), because the sensitive phosphatase-staining method allowed detection of the Pho+ mating-competent derivatives from confluent colonies by the random spore method. Our study describes a rapid and convenient method for isolating mating-competent clones from industrial yeasts.

Amino Acid Sequence↗
PubMed2001

Evaluation of the retinal nerve fiber layer thickness in eyes with idiopathic macular holes.

PURPOSE: To compare the retinal nerve fiber layer thickness in eyes with idiopathic macular holes and age-matched normal controls using scanning laser polarimeter. METHODS: The retinal nerve fiber layer thickness was measured in 40 eyes of 40 consecutive patients with idiopathic macular hole (stage 1, 10 eyes; stage 2, eight eyes; stage 3, 15 eyes; stage 4, seven eyes) and 40 eyes of 40 age-matched normal controls with a scanning laser polarimeter. The retinal nerve fiber layer thickness within a 10-pixel-wide ellipse located concentrically with the disk and located 1.5-disk diameters from the center of the disk was measured. The mean overall retinal nerve fiber layer thickness of the peripapillary retina, four 90-degree quadrants, and 16 equal sectors of every 22.5 degrees was calculated for both groups. The retinal nerve fiber layer thickness in the two groups was statistically compared. RESULTS: The mean retinal nerve fiber layer thickness measurement for the overall peripapillary retina and for three of the four 90-degree quadrants was not significantly different between the two groups. However, the temporal 90-degree quadrant was significantly thinner in the macular hole group (47.2 versus 54.6 microm, P =.026). For the 16 sectors of 22.5 degrees, the lower three sectors of the four sectors in the temporal quadrant were thinner in the macular hole group (P <.05). CONCLUSIONS: The retinal nerve fiber layer thickness of the papillomacular area is thinner in eyes with idiopathic macular hole than that in normal eyes. The progressive thinning of the retinal nerve fiber layer thickness as the stage of the macular hole advances may suggest that surgery should be done at the earliest stage.

Aged↗
PubMed2001

Pulmonary atresia, ventricular septal defect, and coronary-pulmonary artery fistula.

We report 2 patients with pulmonary atresia, ventricular septal defect, and coronary-pulmonary fistula. The fistula originated from the left anterior descending artery in 1 patient, and from the right coronary artery in the other. Both patients survived staged correction in which right ventricular outflow was reconstructed with autologous fistula tissue. One patient with pulmonary hypertension suddenly died 9 months after surgery. Twenty-four patients with pulmonary atresia, ventricular septal defect, and coronary-pulmonary fistula have been reported previously.

Arterio-Arterial Fistula↗