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Biomedical subjects

Y Oshima

Publications and source records attributed to Y Oshima.

At least 271 records · Page 15Linked to original sources
PubMed1990

Concomitant repair of congenital tracheal stenosis and complex cardiac anomaly in small children.

Severe obstructive lesion of the trachea combined with complex congenital cardiac anomaly has generally been regarded as a fatal disease. Herein we report the successful concomitant repair of severe tracheal stenosis and complex cardiac anomaly with the use of cardiopulmonary bypass in two cases. The first patient was a 5-year-old boy with tetralogy of Fallot associated with a localized intrathoracic tracheal stenosis caused by complete cartilaginous rings. Tracheal resection and end-to-end anastomosis combined with total correction of tetralogy of Fallot was performed with the aid of cardiopulmonary bypass. The second patient was a 5-month-old girl with a pulmonary artery sling, scimitar syndrome, and extensive tracheal stenosis. The patient underwent definitive correction of cardiac lesions and complete tracheal reconstruction with a cartilaginous graft with the aid of cardiopulmonary bypass. Utmost care was paid to avoid contamination during the operation. Both of the patients are doing well at present without any signs of complication, 2 years 5 months and 1 year 10 months after the operation, respectively. We advocate concomitant repair of both lesions, with cardiopulmonary bypass, in the surgical managements of infants and small children who have a difficult and otherwise fatal combination of complex congenital cardiac anomaly and severe intrathoracic tracheal stenosis.

Cardiopulmonary Bypass↗
PubMed1990

[Clinical evaluation of various methods of myocardial protections during open heart surgery in infants with ventricular septal defect and severe pulmonary hypertension].

The effectiveness of various methods of myocardial protection were evaluated retrospectively in 59 infants less than 12 months of age who underwent open heart surgery for ventricular septal defect with severe pulmonary hypertension. Intermittent aortic clamping and electrically induced ventricular fibrillation (EF) were employed in 13 infants (Group I), and potassium induced cold cardioplegia and topical cardiac cooling (TC) were used in 14 infants (Group II). Six infants in Group II had additional EF after declamping of the aorta (Group II-A) but the rest of Group II infants did not have any EF (Group II-B). Profound hypothermia and circulatory arrest were utilized in 17 infants (Group III). Cold blood cardioplegia with TC were used in 15 infants (Group IV). Moderate hypothermia were used during cardiopulmonary bypass in Group I, II and IV. The operative mortality for Group I was 15% and was 0% for Group II, III and IV. The incidence of spontaneous resumption of cardiac beat following declamping of the aorta were 33.3, 0, 100, 94.1, 93.3% for Group I, II-A, II-B, III and IV respectively. The urinary output obtained in the postoperative 72 hours was significantly lower in Group I than in Group II, III and IV (Group I less than II less than IV less than III).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Bypass↗
PubMed1989

Increased intraglomerular thrombin formation in diabetic microangiopathy.

Estimations of soluble fibrin monomer complexes (SFMC) in plasma are a convenient index of thrombin activation. Renal venous-arterial differences in plasma SFMC concentrations were determined in 16 randomly chosen diabetic patients by sampling directly and simultaneously from the renal artery and vein according to the method of Seldinger. In all subjects, SFMC concentrations were higher in the renal vein than in the renal artery, indicating that the kidney is an important source of SFMC. Venous-arterial differences were markedly elevated in patients with severe renal and retinal microangiopathy coupled with hypertension. The hypothesis is advanced that elevated plasma SFMC levels lead to abnormal fibrin deposits in lesioned glomeruli and retinal vessels. It is postulated that plasma SFMC may be a useful parameter for the assessment of diabetic vascular complications.

Adult↗
PubMed1989

An autonomously replicating sequence of pSRI plasmid is effective in two yeast species, Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

The autonomously replicating sequences (ARSs) of pSR1, a cryptic circular DNA plasmid detected in a strain of Zygosaccharomyces rouxii, were delimited by subcloning and deletion analysis and by the isolation of nucleotide substitution mutations. A 30 base-pair (bp) sequence from inverted repeat 1 (IR1) and presumably the same region from IR2 of pSR1 functions as an ARS in the native host, Z. rouxii, and in a heterologous host, Saccharomyces cerevisiae. Thus, pSR1 has two ARSs per molecule, either of which is sufficient for replication of the plasmid molecule in both hosts. These hosts, however, respond differently to nucleotide substitutions in the 30 bp sequence, suggesting that the sequences required for ARS function in the two organisms are not exactly the same. In addition, a 137 bp sequence that overlaps the 30 bp sequence by 11 bp also functions as an ARS in Z. rouxii but not in S. cerevisiae. However, this 137 bp sequence enhances the stability of plasmids carrying the pSR1 ARS in S. cerevisiae. The 30 bp and 137 bp sequences each contain a single copy of the 11 bp ARS consensus sequence, which is essential for ARS function in S. cerevisiae. Small insertions between the 11 bp overlapping region and the 11 bp ARS consensus sequence showed that a proper distance between these two 11 bp sequences is essential for the ARS function of the 30 bp sequence. Point mutations that inactivate ARS function show that the ARS consensus sequence, as well as a short A:T segment in the overlapping sequence, is required for the ARS function of the 30 bp sequence.

Base Sequence↗
PubMed1989

Plasmid multimerization is dependent on RAD52 activity in Saccharomyces cerevisiae.

A mutant plasmid, pX, derived from the 1453 base pair small plasmid, YARp1 (or TRP1 RI circle), consists of 849 base pairs of DNA bearing the TRP1 gene and the ARS1 sequence of Saccharomyces cerevisiae and, unlike YARp1 and other commonly used yeast plasmids, highly multimerizes in a S. cerevisiae host. The multimerization of pX was dependent on RAD52, which is known to be necessary for homologous recombination in S. cerevisiae. Based upon this observation, a regulated system of multimerization of pX with GAL1 promoter-driven RAD52 has been developed. We conclude that the regulated multimerization of pX could provide a useful model system to study genetic recombination in the eukaryotic cell, in particular to investigate recombination intermediates and the effects of various trans-acting mutations on the multimerization and recombination of plasmids.

DNA, Circular↗
PubMed1989

Molecular characterization of a specific p-nitrophenylphosphatase gene, PHO13, and its mapping by chromosome fragmentation in Saccharomyces cerevisiae.

The structural gene, PHO13, for the specific p-nitrophenyl phosphatase of Saccharomyces cerevisiae was cloned and its nucleotide sequence determined. The deduced PHO13 protein consists of 312 amino acids and its molecular weight is 34635. The disruption of the PHO13 gene produced no effect on cell growth, sporulation, or viability of ascospores. The PHO13 locus was mapped at 1.9 centimorgans from the HO locus on the left arm of chromosome IV. By chromosome fragmentation, the PHO13 locus was found to be located about 72 kb from the left-hand telomere of chromosome IV and distal to the HO locus.

4-Nitrophenylphosphatase↗
PubMed1989

Mode of expression of the positive regulatory genes PHO2 and PHO4 of the phosphatase regulon in Saccharomyces cerevisiae.

The mode of expression was investigated for two positive regulatory genes, PHO2 and PHO4, whose products are indispensable for the transcriptional control of the structural genes of repressible acid phosphatase and the inorganic phosphate (Pi) transport system in Saccharomyces cerevisiae. Northern analysis of poly(A)+ RNA of the wildtype and the pho regulatory mutants with PHO4 DNA as hybridization probe and expressional analysis of a pho4'-'lacZ fused gene on a YEp plasmid revealed that PHO4 is expressed at a low level, constitutively, and independently of the PHO regulatory system and Pi in the medium. Similar analyses with PHO2 DNA indicated that PHO2 is expressed at an even lower level than PHO4, and is repressed by Pi and by the active PHO2 product, possibly at the translational level, while retaining a substantial level of basal activity.

Acid Phosphatase↗
PubMed1989

Function of the PHO regulatory genes for repressible acid phosphatase synthesis in Saccharomyces cerevisiae.

Expression of the repressible acid phosphatase (rAPase) gene, PHO5, of Saccharomyces cerevisiae is repressed by a certain level of inorganic phosphate (Pi) in the medium and is derepressed when the Pi concentration is lowered. The Pi signals are conveyed to PHO5 by a regulatory system consisting of proteins coded for by the PHO2, PHO4, PHO80 and PHO81 genes. We have found that the transcription of PHO81 is regulated by Pi through the PHO regulatory system. Increasing the dosage of PHO4 and PHO81 by ligating each gene to YEp13 gives rise to, respectively, considerable and weak synthesis of rAPase by cultivation of the transformants in high-Pi medium; but in low-Pi medium, increased dosage of PHO4 stimulates the rAPase synthesis significantly, whereas PHO81 has no effect. Increased dosage of PHO2 stimulates rAPase synthesis considerably in low-Pi but not in high-Pi. A coordinate increase of PHO80 cancels the dosage effect of PHO4, but not that of PHO81. Coordinate increases of PHO80 and PHO2 give rise to the same phenotype as an increased dosage of PHO80 alone. The level of the PHO4 protein was found to be the limiting factor of the rAPase synthesis and the copy number of the PHO5 gene not to be. These facts accord with the idea that the PHO80 protein transmits the Pi signals to the PHO5 gene via the PHO4 protein, whereas the PHO2 protein does not have a direct function in the signal transmission.

Acid Phosphatase↗
PubMed1989

Scopolamine impairs both working and reference memory in rats: a replication and extension.

Rats were trained to run in a spatial, radial maze for sucrose reward using a procedure that permitted determination of two memory functions [working memory (WM) and reference memory (RM)]. Injections of saline, 0.1, 0.4, and 0.8 mg/kg of scopolamine hydrobromide were administered using a Latin-square design; a single dose (0.4 mg/kg) of scopolamine methylbromide served as a control for peripheral drug effects. The smallest dose of scopolamine (0.1 mg/kg) had no measurable effect on performance, but as the dose was increased to 0.4 and 0.8 mg/kg there were increases in both WM and RM errors, in errors of omission, and increases in running time. These results support the view that the effects of scopolamine on performance in the radial maze is not specific for working memory, but rather the effects are more general in nature.

Animals↗
PubMed1989

Isolation and hypoglycemic activity of trichosans A, B, C, D, and E: glycans of Trichosanthes kirilowii roots.

The non-dialyzable portion of the water extract of the Oriental crude drug "karokon", the roots of Trichosanthes kirilowii, was found to reduce the plasma glucose level in mice. Activity-guided fractionation of this non-dialyzable portion led to the isolation of five glycans termed as trichosans A, B, C, D and E, showing hypoglycemic actions in normal mice. The main glycan, trichosan A, also exhibited activity in alloxan-induced hyperglycemic mice.

Animals↗
PubMed1989

Mating-type control in Saccharomyces cerevisiae: isolation and characterization of mutants defective in repression by a1-alpha 2.

The alpha 2 protein, the product of the MAT alpha 2 cistron, represses various genes specific to the a mating type (alpha 2 repression), and when combined with the MATa1 gene product, it represses MAT alpha 1 and various haploid-specific genes (a1-alpha 2 repression). One target of a1-alpha 2 repression is RME1, which is a negative regulator of a/alpha-specific genes. We have isolated 13 recessive mutants whose a1-alpha 2 repression is defective but which retain alpha 2 repression in a genetic background of ho MATa HML alpha HMRa sir3 or ho MAT alpha HMRa HMRa sir3. These mutations can be divided into three different classes. One class contains a missense mutation, designated hml alpha 2-102, in the alpha 2 cistron of HML, and another class contains two mat alpha 2-202, in the MAT alpha locus. These three mutants each have an amino acid substitution of tyrosine or acid substitution of tyrosine or phenylalanine for cysteine at the 33rd codon from the translation initiation codon in the alpha 2 cistron of HML alpha or MAT alpha. The remaining 10 mutants make up the third class and form a single complementation group, having mutations designated aar1 (a1-alpha 2 repression), at a gene other than MAT, HML, HMR, RME1, or the four SIR genes. Although a diploid cell homozygous for the aarl and sir3 mutations and for the MATa, HML alpha, and HMRa alleles showed alpha mating type, it could sporulate and gave rise to asci containing four alpha mating-type spores. These facts indicate that the domain for alpha2 repression is separable from that for a1-alpha2 protein interaction or complex formation in the alpha2 protein and that an additional regulation gene, AAR1, is associated with the a1-alpha2 repression of the alpha1 cistron and haploid-specific genes.

Amino Acid Sequence↗
PubMed1989

[Surgical repair of scimitar syndrome by direct anastomosis between right pulmonary vein and left atrium].

A surgical case of 8-year-old boy with scimitar syndrome is presented. The patient was admitted to the hospital because of exertional dyspnea and underdevelopment. Cardiac catheterization revealed a large amount of left to right shunt and O2 step up at the level of the inferior vena cava below the diaphragm. Angiography showed that the pulmonary vein draining the right lower lobe pierced the diaphragm and emptied into IVC. At operation the right pleural cavity was entered and a large anomalous pulmonary vein trunk was found which headed downward and medially and eventually entered in the diaphragm. A direct anastomosis between the scimitar vein and left atrium was made. To avoid kinking or stenosis of this vein, the parenchyma of the right lung (S7) was divided to create a passway of the vein. Anastomosis was performed without excessive tension or kinking on it. We conclude that the method applied in this case might be a procedure of choice for the repair of scimitar syndrome especially when there is no associating atrial septal defect or scimitar vein drains into IVC at the level lower than hepatic vein.

Anastomosis, Surgical↗
PubMed1989

[Surgical treatment of interrupted aortic arch in infants under three months of age].

From March, 1982, through March, 1988, 8 infants less than 3 months of age underwent surgical treatment of interrupted aortic arch. Five patients had IAA type A and 3 patients had type B. Seven patients with associated VSD underwent staged operations and 1 infant with aortopulmonary window underwent primary repair off cardiopulmonary bypass. Aortic arch reconstruction was by subclavian aortic anastomosis (6) or large tube graft (8 mm) interposition (2) combined with pulmonary artery banding (5). All seven patients with associated VSD survived the first-stage operation. One patient subsequently underwent pulmonary artery banding, two underwent patch aortoplasty and four patients underwent intracardiac repair and removal of a pulmonary artery band, with six survivors (86%). The operative death occurred in an infant in whom modified Damus-Kaye-Stansel operation was carried out for severe subaortic stenosis, which rerouting all left ventricular blood through VSD and the main pulmonary artery into the ascending aorta and reconstructing right ventricular-distal pulmonary artery connection by a valved external conduit. All six surviving patients are doing well at present (mean follow up of 3 years) without any significant pressure gradient between the ascending and thoracic aorta. Based on these data we conclude: (1) Aortic arch reconstruction and pulmonary artery banding can be reliably performed even in critically ill infants with IAA and isolated VSD. (2) The primary repair will provide better chance of survival in infants with IAA associated with significant LVOTO, truncus arteriosus or aortopulmonary window that do not readily lend themselves to pulmonary artery banding.

Anastomosis, Surgical↗
PubMed1989

[The influence of disinfectants on colloidal impression materials and dental stones].

In view of prophylaxis against hospital infections, following tests were performed: Two kinds of alginate impression materials (ALGIACE and Aligix-S) and two kinds of agar impression materials (CARTRIILLOID and RUBBERLLOID) were immersed for 30 minutes in the following six kinds of disinfectants; 0.1% benzethonium chloride (benzethonium), 1% chlorhexidine gluconate (hexidine), 1% chlorhexidine gluconate added with surfactants (hexidine surfactant), 1% sodium hypochlorite (hypochlorous acid), 2% glutaraldehyde (glutaral) and 1% formaldehyde (formalin). Changes in size of the impression materials with time were then measured. Three kinds of dental stones (SHIMOMURA DENTAL PLASTER, NEW PLASTONE and SURSTONE) were infused into the impression surfaces after treatment with disinfectants, and the surface roughness and hardness of the yielded surfaces of the samples were measured. The results obtained are as follows: 1) As to ALGIACE, although the rates of changes in size lay within the range of +/- 0.3% when immersed in hexidine, hexidine surfactant and hypochlorous acid, the infusion of either one of SHIMOMURA DENTAL PLASTER, NEW PLASTONE or SURSTONE into the impression showed an effect on the stone surface. 2) As to Algix-S, the rate of changes in size lay within the range of +/- 0.3% when immersed in all the disinfectants, and the influsions of NEW PLASTONE and SURSTONE after immersing in benzethonium, hexidine surfactant and glutaral gave a slight effect on the stone surface. 3) As to CARTRILLOID, the rates of change in size lay within the range of +/- 0.3% except for the immersion in hexidine; the influsion of SHIMOMURA DENTAL PLASTER into the impression, the influsion of NEW PLASTONE after immersing in benzethonium and formalin and the influsions of NEW PLASTONE and SURSTONE after immersing in glutaral gave a slight effect on teh stone surface. 4) As to RUBBERLLOID, the rates of changes in size lay within the range of +/- 0.2% when immersed each disinfectant; the influsion of SHIMOMURA DENTAL PLASTER after immersing in hypochlorous acid and that of either one of SHIMOMURA DENTAL PLASTER, NEW PLASTONE or SURSTONE after immersing in benzethonium, glutaral and formalin gave a slight effect on the stone surface.

Calcium Sulfate↗
PubMed1989

[Thoracoabdominal ectopia cordis with single ventricle and pulmonary stenosis. A case report of successful surgical repair].

A case of thoracoabdominal ectopia cordis with single ventricle and pulmonary stenosis is reported. A cyanotic boy with omphalocele was brought to our hospital soon after his birth and was diagnosed as thoracoabdominal ectopia cordis with single ventricle and pulmonary stenosis. A conservative treatment of omphalocele was performed successfully and a plastic chest shield had been made for him which protected the anterior surface of his chest. He continued to develop in a fairly satisfactory condition and operation was delayed until he was 8 years old when he had severe cyanosis and frequent episodes of headache. The operative procedures were; 1) ascending aorta to main pulmonary artery shunt with EPTFE tube; 2) to bring the heart into the thoracic and abdominal cavity by developing widely the pericardial and diaphragmatic defect behind the heart's preoperative position; 3) to reconstruct the new pericardial sac lying from thoracic to abdominal cavity by covering the heart using EPTFE sheet. This trial of making a new pericardial sac for thoracoabdominal ectopia cordis is not reported so far in the literature. It is expected that the heart has being raised to the thoracic cavity with patient's physical growth after this operation.

Child↗
PubMed1989

[Successful simultaneous repair of tetralogy of Fallot and congenital tracheal stenosis in a 5-year old child].

Congenital cardiac anomaly combined with severe obstructive lesion of airway remains a surgical challenge. A case of 5-year old child with tetralogy of Fallot associated with congenital tracheal stenosis (cartilagenous ring) was reported. The patient had history of cyanosis and stridor since age 3 months and had been hospitalized repeatedly for recurrent respiratory distress. The diagnosis was first established and emergent Blalock-Taussig shunt was carried out during first admission at age 1 year and 7 months. On the fourth admission at age 5 year, a definitive surgical intervention was decided following re-evaluation of the patient by cardiac catheterization, bronchoscopy and bronchography. Trachea and heart were exposed through cervical collar and presternal skin incision and median sternotomy. Tracheal resection and end-to-end anastomosis combined with total correction of tetralogy of Fallot was carried out under cardiopulmonary bypass. Utmost care was paid to avoid contamination during the operation. He was extubated at 9th postoperative day and has been free from symptom 9 months after the operation.

Cardiopulmonary Bypass↗
PubMed1989

[Attempt of intracranial IC bypass for giant aneurysm in the cavernous portion of the carotid artery].

We report here, a novel method for internal carotid (IC) bypass between C2 and C5, by using the autologous saphenous vein. The patient was a 58 year-old female, complaining of pain and motor disturbance in her right ocular region. She suddenly developed left-sided hemiparesis during her stay in our hospital. The following CT examination demonstrated a high density homogenous round mass, which occupied the right side of the parasellar region with no perifocal edema. The contrast enhancement CT, however, suggested there was still a certain degree of blood flow in the mass. On the other hand, carotid angiography showed an occlusion of blood flow at the C5 level (interosseous portion), which seemed to indicate either giant aneurysm or cavernous angioma. The mass was identified as a giant aneurysm during surgery, and the decompression procedure by removing the intra-aneurysmal blood clot was attempted first. However, this trial failed due to an accidental severe bleeding. Because of this, we then decided to perform the grafting of autologous saphenous for a length of 10 cm between C2 and C5. Intraoperative heavy bleeding mentioned above seemed to have occurred due to release of compression by the aneurysm against the internal carotid artery through which there was restricted blood flow. Postoperative angiography demonstrated that the graft remained patent enough to be approximately equal in size to the original artery. From our experiences in this case, two important points are, we suggest, to be kept in mind while applying this method; (1) to carefully expose the C5 segment, (2) to avoid damage of the surrounding structures such as the Eustachian tube, facial nerve and cochlear nerves, and so forth. In conclusion, we strongly recommend this IC bypass technique for other types of tumors in the cavernous portion as well.

Carotid Artery Diseases↗