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Biomedical subjects

Y Oshima

Publications and source records attributed to Y Oshima.

At least 289 records · Page 16Linked to original sources
PubMed1989

[Early and late results of surgical treatment of coarctation of the aorta in infants less than six months of life--including the propriety of pulmonary artery banding].

During an 8-year period, 53 infants less than six months of life underwent repair of coarctation of the aorta (CoA). Preoperatively 58 percent of patients received intensive circulatory and/or respiratory care. The diagnosis was established by echocardiography and counter current aortography via a radial artery in the majority of recent cases and the surgical relief of CoA was effected within 24 hours of the diagnosis. The last 51 patients were managed under the policy of simple repair of the CoA in patients with significant VSD (Group II), with the addition of pulmonary artery banding for patients with complex cardiac lesions with VSD (Group III) or for patients with incremental risk factors in Group II such as prematurity of body weight of less than 1500 gm, other organ anomalies requiring major operation in neonate, pulmonary complications or severe malnutrition. There was no intraoperative death, one (2%) postoperative and five (10%) late deaths among the lost 51 patients. Only one (2%) showed sign of recurrence among 46 patients followed for 16-112 (mean 47) months.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Coarctation↗
PubMed1989

[False aneurysm of the right pulmonary artery--a rare complication of aorto-pulmonary shunt in a patient with tricuspid atresia].

A 12-year-old girl with tricuspid atresia who underwent a side-to-end anastomosis between the ascending aorta and the right pulmonary artery at the age of two months, developed a false aneurysm of the right interlobar trunk artery. The diagnosis was established by angiography, computed tomography and bronchoscopy. Emergency surgical intervention was required because of impending aneurysmal rupture into the right interlobar bronchus. Creation of a left Blalock-Taussig shunt to tide over the anticipated postoperative hypoxemia and right middle and lower lobectomy were carried out successfully. The false aneurysm in this case occurred following an episode of a streptococcal infection and was probably mycotic in origin. But it is possible that the presence of aorto-pulmonary shunt itself might have affected as a predisposing factor for aneurysm formation in this case.

Aneurysm, Infected↗
PubMed1989

[Operative technique of systemic to pulmonary artery shunt and aortoplasty utilizing in aberrant subclavian artery].

This paper presents a review of our experience of 3 cases of systemic to pulmonary artery shunt operation and 2 cases of subclavian flap aortoplasty using aberrant subclavian artery. The aberrant subclavian arteries were divided to release the vascular rings and were used as shunt grafts or reversed subclavian flaps. In case of shunt operation, this graft would be superior to the EPTFE graft of modified Blalock-Taussig shunt, from the point of view of the grafts' growth ability. In case of aortoplasty, if arch hypoplasia exists, this flap can repair it beyond the coarctation segment. When the aberrant subclavian artery is dissected, it should be avoided to use the contralateral subclavian artery, as it may cause cerebral damage because of the impairment of bilateral vertebral arterial circulation.

Aorta↗
PubMed1989

A new technique for use of an anomalous subclavian artery for a systemic-pulmonary arterial shunt.

Anomalous subclavian arteries were used as interposition grafts for systemic-pulmonary arterial shunts in three infants and children with good early and long-term results. This is the first report of the use of an anomalous subclavian artery as an interposition graft for a systemic-pulmonary arterial shunt. The advantages and effectiveness of the technique are discussed.

Anastomosis, Surgical↗
PubMed1988

Some chemical properties of maitotoxin, a putative calcium channel agonist isolated from a marine dinoflagellate.

Maitotoxion, a putative Ca2+ channel agonist, was isolated from cultures of the marine dinoflagellate Gambierdiscus toxicus as a colorless amorphous solid. The toxin reacted positively to Dragendorff's reagent but not to ninhydrin reagent. The mouse lethality of maitotoxin determined by intraperitoneal injection was 0.13 micrograms/kg. Chemical features of the toxin were elucidated mainly by various spectroscopic measurements. The molecular weight of maitotoxin as a disodium salt was estimated to be 3,424.5 +/- 0.5 from the negative fast atom bombardment (FAB) mass spectrum. The presence of two sulfate ester groups in the molecule was apparent from the IR and mass spectra, and from analyses of solvolysis products. Despite of its large size, maitotoxin seems to have no known repeating units, such as amino acids and sugars, no carbonyl groups, no side chains other than methyls or an exomethylenes, and no carbocycles.

Animals↗
PubMed1988

Gene conversion associated with site-specific recombination in yeast plasmid pSR1.

A circular DNA plasmid, pSR1, isolated from Zygosaccharomyces rouxii has a pair of inverted repeats consisting of completely homologous 959-base pair (bp) sequences. Intramolecular recombination occurs frequently at the inverted repeats in cells of Saccharomyces cerevisiae, as well as in Z. rouxii, and is catalyzed by a protein encoded by the R gene of its own genome. The recombination is, however, independent of the RAD52 gene of the host genome. A site for initiation of the intramolecular recombination in the S. cerevisiae host was delimited into, at most, a 58-bp region in the inverted repeats by using mutant plasmids created by linker insertion. The 58-bp region contains a pair with 14-bp dyad symmetry separated by a 3-bp spacer sequence. The recombination initiated at this site was accompanied by a high frequency of gene conversion (3 to 50% of the plasmid clones examined). Heterogeneity created by the linker insertion or by a deletion (at most 153 bp so far tested) at any place on the inverted repeats was converted to a homologous combination by the gene conversion, even in the rad52-1 mutant host. A mechanism implying branch migration coupled with DNA replication is discussed.

Base Sequence↗
PubMed1987

Structure of the yeast HIS5 gene responsive to general control of amino acid biosynthesis.

The nucleotide sequence of a 2.1 kb DNA fragment bearing the HIS5 gene of Saccharomyces cerevisiae, which encodes histidinol-phosphate aminotransferase (EC 2.6.1.9), has been determined. An open reading frame of 1,152 bp was found. S1 nuclease mapping indicated that the major transcription starts at position -37 from the ATG codon and the minor (approximately 20%) at -34 in both repressive and derepressive conditions. Northern analysis indicated that transcription of the HIS5 gene is under the general control of amino acid biosynthesis. The 5' noncoding region of the gene, thus far examined up to position -616, contains three copies of sequences homologous to the short repeats of the consensus sequence, 5'-AATGTGACTC-3', suggested for general amino acid control in the HIS1, HIS3, HIS4, and TRP5 at positions -336, -275 and -205. The consensus sequence closest to the open reading frame was shown to be necessary but not sufficient for general amino acid control, by examination of beta-galactosidase appearance in S. cerevisiae cells carrying various mutant HIS5 promoter regions fused to the lac'Z gene and inserted at the leu2 locus of chromosome III.

Amino Acid Sequence↗
PubMed1987

Molecular structure of the replication origin of a Bacillus amyloliquefaciens plasmid pFTB14.

The structure of a 1.5-kb DNA sequence that is necessary and sufficient for the replication of an 8.2-kb cryptic plasmid, pFTB14, isolated from a strain of Bacillus amyloliquefaciens has been characterized. The 1.5-kb DNA sequence contains an open reading frame, rep, stretching for 1017 bp, a promoter region for rep expression, and a possible replication origin for the plasmid upstream of the promoter. The rep product is trans-active and essential for plasmid replication. The predicted rep protein is a basic protein, as are the RepC protein of pT181, RepB of pUB110 and protein A of pC194 (all these found in staphylococci) and the pi protein of the R6K plasmid of Escherichia coli. The predicted rep protein has highly homologous amino acid sequences with protein A of pC194 and RepB of pUB110 throughout the protein molecule, but not with RepC of pT181, pi of R6K or protein RepH encoded by and initiating the replication of pC194.

Amino Acid Sequence↗
PubMed1987

Dinoflagellate Gymnodinium catenatum as the source of paralytic shellfish toxins in Tasmanian shellfish.

Paralytic shellfish toxins in both cultured cells and natural phytoplankton blooms of the dinoflagellate Gymnodinium catenatum from inshore Tasmanian waters (Australia) were analyzed by high performance liquid chromatography, thin layer chromatography and electrophoresis techniques. The dinoflagellate toxins were dominated by low potency sulfocarbamoyl saxitoxin derivatives (98-99 mole% in total), including gonyautoxin VIII (C2) and its epimer (C1) and sulfocarbamoyl gonyautoxins I and IV (C3 and C4). Mussels and oysters contaminated by the dinoflagellate showed similar toxins, but contained larger proportions of C3 (40-57 mole%) and more potent carbamate toxins (7-23 mole% total).

Animals↗
PubMed1987

Structural characteristics of the PHO8 gene encoding repressible alkaline phosphatase in Saccharomyces cerevisiae.

The nucleotide sequence of a 3694-bp DNA fragment bearing the PHO8 gene encoding nonspecific repressible alkaline phosphatase (rALPase; EC 3.1.3.1) of Saccharomyces cerevisiae was determined. The sequence contains a 1698 bp open reading frame (ORF), and the major PHO8 transcription start point at 32 bp upstream from the ATG codon; several minor transcription start points are located between the major start point and ATG. The major start point is most responsive to the phosphate signals. The amino acid (aa) sequence deduced from the ORF contains several homologous regions in common with alkaline phosphatases of Escherichia coli and human placenta. A PHO8 DNA fragment previously isolated [Kaneko et al., Mol. Cell. Biol. 5 (1985) 248-252] was found to be truncated for the region encoding the 22 aa residues at the C terminus of the enzyme, which were replaced with 17 aa encoded by a pBR322 DNA. The modified gene could produce significant rALPase activity without the function of proteinase A which is required for the maturation of rALPase from its precursor.

Alkaline Phosphatase↗
PubMed1987

Studies on zoapatle. V. Correlation between in vitro uterine and in vivo pregnancy interruption effects in guinea pigs.

The zoapatle plant, Montanoa tomentosa, has an extensive ethnomedical history of use in fertility regulation. Several fractions and isolates of this plant were evaulated in in vitro and in vivo tests to identify and characterize active constituents which may be responsible for its antifertility effects. The guinea pig was the animal model. Two types of in vitro activity were observed, a uterotonic type effect and an inhibition of spontaneous contractions of the uterine muscle. The in vivo effects appear to correlate with the ability of a fraction/isolate to inhibit the spontaneous contractions in in vitro testing. The non-polar fractions/isolates accounted for the inhibition of spontaneous contraction effects and the in vivo activity. The more polar fractions/isolates accounted for the uterine stimulant activity.

Abortifacient Agents↗