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Y Oshima

Publications and source records attributed to Y Oshima.

At least 235 records · Page 13Linked to original sources
PubMed1992

Functional analysis of box I mutations in yeast site-specific recombinases Flp and R: pairwise complementation with recombinase variants lacking the active-site tyrosine.

The site-specific recombinases Flp and R from Saccharomyces cerevisiae and Zygosaccharomyces rouxii, respectively, are related proteins that belong to the yeast family of site-specific recombinases. They share approximately 30% amino acid matches and exhibit a common reaction mechanism that appears to be conserved within the larger integrase family of site-specific recombinases. Two regions of the proteins, designated box I and box II, also harbor a significantly high degree of homology at the nucleotide sequence level. We have analyzed the properties of Flp and R variants carrying point mutations within the box I segment in substrate-binding, DNA cleavage, and full-site and half-site strand transfer reactions. All mutations abolish or seriously diminish recombinase function either at the substrate-binding step or at the catalytic steps of strand cleavage or strand transfer. Of particular interest are mutations of Arg-191 of Flp and R, residues which correspond to one of the two invariant arginine residues of the integrase family. These variant proteins bind substrate with affinities comparable to those of the corresponding wild-type recombinases. Among the binding-competent variants, only Flp(R191K) is capable of efficient substrate cleavage in a full recombination target. However, this protein does not cleave a half recombination site and fails to complete strand exchange in a full site. Strikingly, the Arg-191 mutants of Flp and R can be rescued in half-site strand transfer reactions by a second point mutant of the corresponding recombinase that lacks its active-site tyrosine (Tyr-343). Similarly, Flp and R variants of Cys-189 and Flp variants at Asp-194 and Asp-199 can also be complemented by the corresponding Tyr-343-to-phenylalanine recombinase mutant.

Binding Sites↗
PubMed1992

[Long-term results of the Blalock-Taussig shunts].

One-hundred and thirty-six patients received the classical Blalock-Taussig shunts between 1980 and 1990. Their age range at operation was 4 days to 12.8 years and their median age was 13 months. The operative mortality rate was 0.7% (1/136). The survivors were followed up from 1 month to 11.5 years, 5.4 years in average. Twenty-five patients required another shunt and the mean interval to that procedure was 2.4 years (modified Blalock-Taussig 23, classical Blalock-Taussig 2, Glenn 1, internal mammary artery-pulmonary artery shunt 1). Forty-five patients received corrective operations, there were four operative deaths (Fontan 2, Rastelli 2). There were 15 late deaths of which three deaths were not cardiogenic. One year after operation, 91.0% of patients remained in well-palliated condition. At three years after operation, 76.4% of patients continued to be in well-palliated condition. There were twelve neonates in this series. Their age range was 4 to 26 days and their median age was 13 days. There was no operative death. Five patients required second shunt. There were two late deaths. At present, six patients continue to be in well-palliated condition 8 months to 9 years after first operation. Angiographic findings showed the stenotic change of the vascular anastomoses in 49.3% (35/71) of patients. This study suggests that polydioxanone suture (PDS) will be useful for the growth of the anastomoses in Blalock-Taussig operation.

Anastomosis, Surgical↗
PubMed1992

[Blood concentrations of futraful, uracil and 5-fluorouracil (5-FU) after UFT administration in the various reconstructions after gastrectomy. Saitama UFT Research Group].

The study was undertaken in the total of 58 gastric cancer patients among which 17 of Billroth (BI), 14 of Billroth II (B II) anastomosis after subtotal gastrectomy, and 7 of jejunal interposition, 9 of double tract and 11 of Roux en Y anastomosis after total gastrectomy were included. Blood samples were taken before 200 mg of per oral UFT administration and after 1, 2, 3, 5 and 7hrs. consecutively. The blood Futraful (FT) level in the total gastrectomy groups reached peak concentration within 1hr and kept in relatively high level during the observation period of 7hrs. The time to maximum FT concentration delayed in almost of B I and a few of B II patients. The concentration curves of uracil (URA) and 5-FU were similar in shape, revealing steep increase and decrease except B I anastomosis which showed gentle course. The plotted maximum concentrations of URA and 5-FU in the every type of reconstruction showed a significant correlation in the regression line. In the analysis of AUC, URA/FT was under 10%, suggesting the longer retention of the unmetabolite type of FT and early disappearance of URA. The ratio of 5-FU/FT was indifferent in each reconstruction. 5-FU/URA was higher in subtotal rather than total gastrectomy groups. From the data obtained, blood concentration of 5-FU after UFT administration was considered to depend on the emptying status in the gastrectomies. And moreover, it depended on blood URA level, since FT from which 5-FU was derived, was kept still sufficiently remained during observation period.

Anastomosis, Roux-en-Y↗
PubMed1992

[Accessory tricuspid valve--a report of two cases].

Accessory tricuspid valve is a rare cardiac anomaly. We describe two cases with accessory tricuspid valve. Case 1: A 7-year-old boy underwent repair of tetralogy of Fallot. Under deep hypothermic cardiopulmonary bypass, right ventricle was opened. An accessory tricuspid leaflet was noted to the right side of the VSD attaching to the infundibular septum from medial papillary muscle as a chordal origin. After excision of the accessory tricuspid leaflet, the VSD was closed with a Dacron patch followed by relieve of the right ventricular outflow obstruction and pulmonary valvotomy. Case 2: A 8-year-old boy had Rastelli operation to correct transposition of the great arteries. An accessory leaflet originated from the medial papillary muscle and was floating like a parachute in the way between VSD and aorta. There was no additional apparatus in the pathway between the VSD and aorta after excision of the accessory tricuspid leaflet. Intraventricular tunnel was created with a Dacron patch. Extracardiac conduit between the right ventricle and the distal pulmonary artery was constructed using a valved pericardial roll.

Child↗
PubMed1992

[MRI findings of closed head injury in children; with special reference to the effect of central shearing force].

It is considered that shearing effect as introduced by Holbourn may produce central concussion, diffuse brain swelling and diffuse axonal injury according to its grade of force. MRI was performed in 38 children who had been admitted to our hospital during the previous 1 year for the treatment of closed head injury of varying severity. In 8 out of 38 cases, abnormal high signal intensity was observed in the medial and para-medial brain parenchyma on MRI. All of these 8 cases suffered from head trauma caused by motor vehicle accidents. They included 2 cases of cerebral concussion, 1 of diffuse brain swelling, and 5 cases of diffuse axonal injury. In 2 cases of cerebral concussion, MRI (T2 weighted) revealed only localized high intensity in the corpus callosum, while CT showed normal and subarachnoid hemorrhage only at the interposium. These two children had been unconscious for periods of 20 to 30 minutes. In one case of diffuse brain swelling, MRI (T2W) showed a slightly obscure border between gray and white matter due to generally increased intensity. In 5 cases of diffuse axonal injury, most of these cases manifested lesions at the corpus callosum, deep white matter, periventricular gray matter, pons, midbrain and the cerebellum as demonstrated by high signal intensity on MRI (T2W) while CT in the acute stage showed small hemorrhage at the corpus callosum, corticomedullary junction and mid-brain and in the ventricles. Among these, two cases also demonstrated subdural hematoma and cortical contusional hemorrhage. At 3-4 weeks after injury, the area of high intensity previously demonstrated in the deep white matter and the corpus callosum on MRI (T2W) was reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Axons↗
PubMed1992

Cardiac fibroma. Long-term fate after excision.

Between 1980 and July 1983 three infants and children with cardiac fibromas underwent surgical resection at Kobe Children's Hospital. Two of them survived and have an excellent clinical result 6 years and 7 years postoperatively. The results of late follow-up with the use of 24-hour dynamic electrocardiography, two-dimensional echocardiography, thallium-201 myocardial scintillation scan, and technetium 99m sodium pertechnetate-gated blood pool imaging have proved that the patients are free of arrhythmic episodes, free of recurrence of tumor, have no significant myocardial perfusion defect, and have normal left ventricular function.

Child↗
PubMed1991

Operation of an efficient site-specific recombination system of Zygosaccharomyces rouxii in tobacco cells.

Recombinase encoded by the R gene of pSR1 of Zygosaccharomyces rouxii mediates reciprocal recombination between two specific recombination sites (RSs) to induce excision or inversion of the DNA segment that is flanked by the RSs. We report here that site-specific recombination mediated by this system takes place effeciently in tobacco cells. To monitor the recombination events in tobacco cells, we have constructed two types of cryptic beta-glucuronidase reporter gene in such a way that recombination such as inversion of the construct or excision of the intervening sequence results in their expression. When these cryptic reporter constructs were transiently introduced together with the R gene by electroporation into protoplasts of tobacco cells, beta-glucuronidase activity was detected. The cryptic reporter genes, when stably resident in the chromosome of tobacco cells, were also activated by the R gene. Structural analyses of the genomic DNA isolated from these tobacco cells showed that the R protein did in fact catalyze precise recombination between two copies of RSs in tobacco cells, with resultant activation of the cryptic reporter genes. This observation provides the basis for development of a DNA technology whereby large regions of DNA can be manipulated in plant chromosomes. Potential uses of this recombination system are discussed.

Base Sequence↗
PubMed1991

A new protein kinase, SSP31, modulating the SMP3 gene-product involved in plasmid maintenance in Saccharomyces cerevisiae.

The pleiotropic smp3 mutation on the Saccharomyces cerevisiae chromosome confers three phenotypes, (i) stable maintenance of a heterologous plasmid pSR1 isolated from Zygosaccharomyces rouxii, (ii) slow cell growth, and (iii) temperature-sensitive growth. The SSP31 gene of S. cerevisiae was isolated as a chromosomal DNA fragment suppressing the thermosensitive cell growth of the smp3 mutant when it was ligated into the low-copy vector, YCp50. However, it did not suppress the phenotypes of stable maintenance of pSR1 and slow cell growth of the smp3 mutant, even when ligated into the multicopy vector, YEp24. The nucleotide sequence of SSP31 suggested that it encodes a protein of 148 kDa containing all the conserved domains of protein kinases. The putative SSP31 protein also has a hybrid structure of serine/threonine and tyrosine kinases in the diagnostic subdomains for target specificity of protein kinases. Disruption of SSP31 was not lethal, but resulted in slow cell growth. The SSP31 was mapped between the ilv3 and ura2 loci on chromosome X.

Amino Acid Sequence↗
PubMed1991

Erythroleukemia in a child associated with monosomy 7.

A case of erythroleukemia (EL) associated with monosomy 7 is reported. The EL was diagnosed 20 months after the initial diagnosis of monosomy 7 was made. An immunologic study of the blast cells using a monoclonal antibody was positive for glycophorin A, which suggested that they were of erythroid origin; this was confirmed by electron microscopy. Chemotherapy was started with low dose cytarabine. However, the patient had severe bone marrow suppression and died of pneumonia. Our case shows that monosomy 7 is an abnormality of the pluripotential stem cells, including erythroid cells, that resulted in a true erythroid neoplasm.

Child, Preschool↗
PubMed1991

The PHO80/TUP7 locus in Saccharomyces cerevisiae is on the left arm of chromosome XV: mapping by chromosome engineering.

The PHO80/TUP7 locus in Saccharomyces cerevisiae is reported to be located on the right arm of chromosome XV close to its centromere. In the present study, the locus has been reassigned to the left arm of the same chromosome by reciprocal recombination between chromosomes V and XV at URA3 (on chromosome V) and PHO80/TUP7 loci by using the site-specific recombination system of the yeast plasmid pSR1.

Chromosome Mapping↗
PubMed1991

Mutations in a Saccharomyces cerevisiae host showing increased holding stability of the heterologous plasmid pSR1.

We have isolated Saccharomyces cerevisiae mutants, smp, showing stable maintenance of plasmid pSR1, a Zygosaccharomyces rouxii plasmid. The smp mutants were recessive and were classified into at least three different complementation groups. The three mutants also showed increased stability of YRp plasmids and the mutations are additive for plasmid stability. One mutation, smp1, confers a respiration-deficient (rho0) phenotype and several Rho- mutants independently isolated by ethidium bromide treatment of the same yeast strain also showed increased stabilities of pSR1 and YRp plasmids. The wild-type S. cerevisiae cells showed a strongly biased distribution of pSR1 molecules as well as YRp plasmids to the mother cells at mitosis, while the smp1 mutant did not show this bias. Another mutation, smp3, at a locus linked to ade2 on chromosome XV, confers temperature-sensitive growth. The SMP3 gene encodes a 59.9 kDa hydrophobic protein and disruption of the gene is lethal.

Amino Acid Sequence↗
PubMed1991

Pulmonary origin of left anterior descending coronary artery in tetralogy of Fallot.

We report the case of a 4-year-old girl with an anomalous origin of the left anterior descending coronary artery from the pulmonary artery in association with tetralogy of Fallot. Creation of an intrapulmonary tunnel from a newly created aortopulmonary window to the coronary ostium in the pulmonary trunk and total repair of tetralogy of Fallot were successfully carried out. The advantage of intrapulmonary tunnel technique (Takeuchi method) for this very rare combination is stressed.

Child, Preschool↗
PubMed1991

Surgical treatment of airway obstruction associated with congenital heart disease in infants and small children.

In the last 12 years, 21 patients age 1 month to 5 years (median, 7 months) underwent surgical treatment for severe airway obstruction associated with congenital heart disease. Plico-suspension of the pulmonary artery was carried out in 14 patients with documented severe left bronchial compression by a distended pulmonary artery together with repair of ventricular septal defects (11 patients), repair of large coronary artery fistula (1), division of ductus (1) and pulmonary artery banding (1), with subsequent significant relief of compression. Aortopexy was used in 2 patients with documented severe tracheal compression by a right aortic arch. Five patients had congenital tracheal stenoses (3 extensive, 2 localized). Two of 3 patients with associated complex intracardiac anomalies underwent concomitant repair of both lesions with the use of cardiopulmonary bypass and 1 had a tracheoplasty and pulmonary artery banding. Tracheal reconstruction with a cartilaginous graft together with repair of pulmonary artery sling was carried out in 2 infants. Nineteen patients are alive and well, at a mean follow-up of 87 months. In conclusion, we advocate early aggressive surgical intervention to both lesions to obtain a better result in the management of infants and small children with this difficult and often fatal combination.

Airway Obstruction↗
PubMed1991

AAR2, a gene for splicing pre-mRNA of the MATa1 cistron in cell type control of Saccharomyces cerevisiae.

We have isolated a class of mutants, aar2, showing the alpha mating type due to a defect in a1-alpha 2 repression but with alpha 2 repression activity from a nonmater strain of Saccharomyces cerevisiae expressing both a and alpha mating-type information in duplicate. Cells of the aar2 mutant and the aar2 disruptant also show a growth defect. A DNA fragment complementing the aar2 mutation contains an open reading frame consisting of 355 amino acid codons. Northern hybridization showed that cells of the aar2 mutant and disruptant contained alpha 1 and alpha 2 transcripts of the MAT alpha gene (or HML alpha in sir3 cells), but their a1 transcript of MATa (or HMRa in sir3 cells) migrated more slowly than that of the wild-type cells on gel electrophoresis and gave a diffused band. Primer extension analysis showed that the aar2 mutant and disruptant have a defect in splicing two short introns of the a1 pre-mRNA but not in splicing pre-mRNA of ACT1. The alpha mating type, but not the slow-growing phenotype, of the aar2 mutant was suppressed by introduction of an intronless MATa1 DNA. Thus, the AAR2 gene is involved in splicing pre-mRNA of the a1 cistron and other genes that are important for cell growth. The AAR2 locus was mapped on chromosome II beside the SSA3 locus, with a 276-bp space, but was not allelic to either PRP5 or PRP6, which are both located on chromosome II and function in splicing pre-mRNA of ACT1.

Amino Acid Sequence↗