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Biomedical subjects

T Kunieda

Publications and source records attributed to T Kunieda.

At least 127 records · Page 7Linked to original sources
PubMed1992

Sexing of mouse preimplantation embryos by detection of Y chromosome-specific sequences using polymerase chain reaction.

Detection of genes known to be present on the mammalian Y chromosome was adapted for sexing mouse early embryos using the polymerase chain reaction (PCR) method. Sry and Zfy genes located in the sex-determining region of the Y chromosome were chosen for Y-specific target sequences, and DXNds3 sequence on the X chromosome was chosen for control. The two-step PCR method using two pairs of primers for each of the target sequences was employed for detecting the sequences. When DNAs of male and female mice were amplified with these primers, male-specific fragments were detected even in DNAs that were equivalent in amount to two cells. Mouse embryos at the two-cell stage were separated into two individual blastomeres, and one blastomere was karyotyped at the second cleavage. The remaining blastomere was subjected to PCR amplification immediately or after having been cultured for 48 h up to the morula stage. The Sry and Zfy sequences were detected in about half the embryos; detection of the Sry and Zfy sequences corresponded exactly to the presence of the Y chromosome, except in one sample of male morula in which embryos may have been lost before the PCR amplification. It is concluded that the sex of mouse preimplantation embryos can be accurately determined through detection of the Y-specific sequences using the two-step PCR method, even with the single blastomeres separated at the two-cell stage.

Animals↗
PubMed1992

Effect of a partial deletion of Y chromosome on in vitro fertilizing ability of mouse spermatozoa.

The effect of a partial deletion of Y chromosome on sperm fertilizing ability was investigated through an in vitro fertilization technique. Epididymal spermatozoa of a congenic line, B10.BR-Ydel, which is characterized by a high incidence of abnormal spermatozoa, revealed a significantly lower in vitro fertilization rate (22%) than that (79%) of its control strain (B10.BR/SgSn), which has a normal-sized Y chromosome. Incidence of capacitated spermatozoa as determined by chlortetracycline fluorescence assay was significantly lower in B10.BR-Ydel than in B10.BR/SgSn spermatozoa. The fertilization rate was significantly improved when B10.BR-Ydel spermatozoa were separated from the supernatant of sperm suspension by Percoll gradient centrifugation. A reconstitution experiment revealed that the B10.BR-Ydel spermatozoa were more sensitive to the inhibitory effect of the supernatant than B10.BR/SgSn spermatozoa. Spermatozoa from F1 (C57BL/6N male x B10.BR-Ydel female) males showed higher fertilization rates than those from F1 (B10.BR.Ydel male x C57BL/6N female) males. These observations suggest that not only the morphology but also the fertilizing ability of spermatozoa is directly related to partial deletion of Y chromosome.

Animals↗
PubMed1992

Pulmonary arterial flow-pressure characteristics in dogs--effects of hypoxia and nitroglycerin.

To investigate the effects of hypoxia and nitroglycerin on pulmonary vascular tone, multipoint mean pulmonary arterial flow-pressure (Q-P relationship) plots were constructed by producing stepwise increments of pulmonary flow with a roller pump installed in a right ventricle-pulmonary artery shunt in 12 mongrel dogs under pentobarbital sodium anesthesia. The normal Q-P relationship was convex to the pressure axis when pulmonary flow was 0-0.2 L/min, but it became linear when pulmonary flow was over 0.2 L/min. The slopes and pressure intercepts extrapolated (RAPI) from linear regression fits to the linear parts of the Q-P relationship were determined to compare the effects of hypoxia and nitroglycerin on pulmonary vascular tone. Hypoxic ventilation (FIO2: 0.1) increased the slope from 8.3 +/- 3.3 to 12.5 +/- 3.6 mmHg/L (p less than 0.01), with no significant effect on PAPI. Nitroglycerin (1 microgram/min/kg as a continuous infusion) decreased the slope from 8.9 +/- 4.4 to 5.8 +/- 2.6 mmHg/L (p less than 0.05), again with no significant effect on PAPI. The results suggest that hypoxia and nitroglycerin, respectively, increased and decreased incremental pulmonary vascular resistance upstream to the site of pulmonary vascular closure.

Animals↗
PubMed1992

An orange-shaped aortic root aneurysm in aortitis syndrome with severe aortic regurgitation.

A 57-year-old man, who had undergone aorto-coronary bypass surgery 4 years before when the shape of the ascending aorta had been normal, had a unique orange-shaped aortic root aneurysm associated with severe aortic regurgitation and congestive heart failure. Replacement of the aneurysm and the aortic valve was successfully carried out, and histopathological examination revealed that the aneurysm was caused by aortitis syndrome.

Aorta, Thoracic↗
PubMed1992

[Comparison of exercise capacity evaluated by cardiopulmonary exercise test and hemodynamic parameters in patients with atrial septal defect].

We evaluated the maximal exercise tolerance using cardiopulmonary exercise testing, and investigated the relation of the hemodynamic parameters such as mean pulmonary artery pressure (PAm) and pulmonic-to-systemic flow ratio (Qp/Qs) to exercise tolerance in 18 adult patients consecutively. All the patients had atrial septal defect (ASD). Maximal oxygen uptake (VO2 max) averaged only 21.6 +/- 5.6 ml/min/kg and 63.5 +/- 16.2% of the predicted values (VO2max). And anaerobic threshold averaged 12.5 +/- 2.3 ml/min/kg and 56.7 +/- 12.4% of the predicted values. There were 2 patients who had marked pulmonary hypertension (PH, PAm more than 44 mmHg). Maximal exercise tolerance of these patients was severely impaired, and %VO2max was only 45.9% and 46.2% respectively. In patients without PH (PAm less than 20 mmHg), however %VO2 max ranged widely from 100.3 to 44.7% and PAm correlated with %VO2max weakly (r = -0.53, p less than 0.05). But there was a significant inverse relationship between Qp/Qs and %VO2max(r = -0.85, p less than 0.01). In 16 patients without PH, maximal O2-pulse during exercise was also inversely correlated with Qp/Qs (r = -0.76, p less than 0.01). The relation between PAm and %VO2max suggests that afterload on the right ventricle may be an important determinant of exercise capacity in patients with PH. And the relation between Qp/Qs and %VO2max or Qp/Qs and % maximal O2-pulse suggests that Qp/Qs may also be a very important determinant factor of exercise capacity in patients without PH.

Adult↗
PubMed1991

Cloning of an activated human ret gene with a novel 5' sequence fused by DNA rearrangement.

By transfecting a high-Mr DNA from human stomach cancer into NIH3T3 cells, a transforming sequence that showed homology with the human ret gene was identified. The transforming sequence was found to be generated by a DNA rearrangement in the human ret proto-oncogene. This rearrangement was suggested to have occurred during the transfection procedure. The nucleotide sequences of cDNAs of the rearranged ret gene and deduced amino acid (aa) sequences revealed that the rearrangement had resulted in recombination of the 3' segment of the ret proto-oncogene with a segment of an unknown human sequence, and that the recombination had generated a novel gene encoding a fusion protein of 435 aa. The rearrangement was presumed to be responsible for activation of the ret gene.

3T3 Cells↗
PubMed1991

Intrapulmonary bronchial blood flow of rats as studied by the microsphere method.

The intrapulmonary bronchial blood flow of the left lung (systemic arterial blood flow to the left lung via the bronchial artery) was determined in 45 anesthetized and artificially ventilated male Wistar rats, weighing 263 +/- 5 g (mean +/- SEM). The microsphere method was employed and designed so that recirculating microspheres across the peripheral arteriovenous anastomoses were prevented from lodging in the left lung, and disturbances of the isovolemic state of the animals became minimal. Under normal conditions with a mean arterial pressure of 115 +/- 2 mmHg (n = 40), the bronchial blood flow of the left lung was found to be 0.307 +/- 0.033 ml/min on average, and amounted to 0.52 +/- 0.06% of the cardiac output. The flow (ml/min) normalized per kg body weight, 100 g wet lung, or 100 g dry lung was 1.14 +/- 0.12, 76 +/- 8, or 368 +/- 39, respectively. The total intrapulmonary bronchial blood flow of the left and right lungs could be estimated by multiplying the intrapulmonary bronchial flow of the left lung by the weight ratio (total:left) of 2.9. The variability of the flow data was small, as confirmed in a study with simultaneous injection of two differently radiolabeled microspheres. The reproducibility of duplicate measurements was excellent.

Animals↗
PubMed1991

Intrapulmonary bronchial circulation during hemorrhage.

Experiments were conducted on 119 anesthetized and artificially ventilated rats to evaluate effects of a physiological stimulus (hemorrhage) to the sympothoadrenal system on the bronchial circulation. In the presence of a sufficient dose of a vasopressin V1-receptor antagonist, moderate (81 mmHg on average, 33 rats) or severe hypotension (69 mmHg, 28 rats) was produced by controlled hemorrhage (11 or 9 rats, respectively), or by treatment with phenoxybenzamine (0.1 mg/kg, i.v., 12 rats, or 1.0 mg/kg, 10 rats), or the highly selective alpha 1-adrenoceptor antagonist, bunazosin (0.01 mg/kg i.v., 10 rats, or 0.1 mg/kg, 9 rats). During hypotension, the intrapulmonary bronchial blood flow (microsphere method) was decreased in a dose-dependent manner in the two antagonist-treated groups. However, these decreases were only of a moderate degree compared to the severe decrease in the hemorrhage group. Although the bronchovascular resistance was not significantly changed after treatment with either antagonist, this variable was greatly elevated during severe hemorrhagic hypotension, reaching 240 +/- 51% (P less than 0.001 with either antagonist study) of its baseline level. Changes in the pulmonary arterial and left atrial pressures, plasma vasopressin concentration, and renin activity were found to be less influential on these responses in 58 rats. Overall, we concluded that the sympathoadrenal mechanism powerfully increased the resistance and decreased the blood flow of the intrapulmonary bronchial circulation.

Animals↗
PubMed1991

Recurrent epicardial fibrosarcoma which arose 12 years after the first resection.

Primary malignant tumours of the heart are very rare, with an incidence of only 0.0017%-0.03% in consecutive autopsy series. Fibrosarcoma of the heart is also rare, representing only about 0.3% of all cardiac tumours. We observed a case of epicardial fibrosarcoma which developed 12 years after the first resection of an epicardial tumour. A 31-year-old woman was referred to our hospital because of fatigue, nausea and right back pain. She had had surgery to resect an epicardial tumour when she was 19 years old. On admission, there was a huge, heterogeneous tumour on the right inferior side of the heart. At surgery, the tumour was totally resected and a pathological diagnosis of fibrosarcoma was made. The patient was free of symptoms for 6 months, but died of a recurrence 11 months after the operation. It is postulated that the epicardial tumour had only been partially resected and had been latent for a rather long period but began to grow rapidly 12 years after the initial resection.

Adult↗
PubMed1991

[Preliminary criteria for the diagnosis of pulmonary hypertension in mixed connective tissue disease].

Based on analysis of data obtained from multicenter patients with collagen diseases (83 with pulmonary hypertension(PH) and 472 without PH), preliminary criteria for the diagnosis of PH in mixed connective tissue disease (MCTD) were proposed by the Research Committee for MCTD of the Ministry of Health and Welfare of Japan. The diagnosis of PH requires four or more out of six clinical and laboratory findings, including exertional dyspnea, systolic pulsation on the left sternum, increased 2nd pulmonary sound, dilatation of the pulmonary artery on chest X-ray, right ventricular hypertrophy on the electrocardiogram, and right ventricular enlargement on the echocardiogram. Alternatively, either an increase of mean pulmonary artery pressure over 25 mmHg measured by right ventricle catheterization, or the corresponding finding on Doppler echocardiography is also valid for the diagnosis of PH. When these criteria were applied to the patients in this study, the sensitivity was 92% and the specificity 100%, showing that PH may be adequately diagnosed using non-invasive methods. The number of criteria satisfied by patients with PH was well correlated with their mean pulmonary artery pressure measured by heart catheterization.

Cardiac Catheterization↗
PubMed1990

Restriction fragment length polymorphisms detected in N-ras-related sequences of rats and their linkage analyses.

Novel restriction fragment length polymorphisms (RFLPs) in inbred rats were revealed with the human N-ras gene as probe. Three fragments hybridizing to the probe were detected by Southern blot hybridization under highly stringent conditions, and one of the fragments showed variation in inbred rat strains. Furthermore, on hybridization under low-stringency conditions, an additional fragment hybridizing to the probe was observed, and this fragment also showed interstrain variation. These two variant fragments showed different distributions in 27 inbred rat strains and segregated in backcross progeny as codominant alleles of independent single autosomal loci. Therefore, the loci for these RFLPs were named Nras-1 and Nras-2, respectively. Analyses of linkages between the RFLPs and 11 other loci revealed that the Nras-2 locus was closely linked to the c locus (3.7 +/- 2.6%), which belongs to rat linkage group I.

Animals↗
PubMed1990

Improvement in pulmonary function in mitral stenosis after percutaneous transvenous mitral commissurotomy.

Before and after percutaneous transvenous mitral commissurotomy (PTMC), pulmonary function studies were performed in 25 patients with mitral stenosis, in order to determine the effects of pulmonary hemodynamics on pulmonary function in patients with mitral stenosis. After PTMC, dramatic improvements in pulmonary hemodynamics were seen in all patients. With regard to pulmonary function data, the VC as percent predicted value increased from 87.6 +/- 16.1 percent to 94.7 +/- 14.4 percent (p less than 0.001). Although the ratio of FEV1/FVC was unchanged, the MVV as percent predicted value increased, and the ratio of RV/TLC, CV, and the difference in nitrogen concentration between 750 ml and 1,250 ml of expired volume decreased significantly. According to the maximum expiratory flow-volume curves, V ax 50% and Vmax 25% improved. Despite marked improvements in pulmonary ventilatory function soon after PTMC, the percent predicted diffusing capacity of the lung for carbon monoxide decreased significantly after PTMC. Arterial blood gas data, such as the partial pressure of oxygen and carbon dioxide in arterial blood and the alveolar-arterial differences in partial pressure of oxygen, did not improve within one or two weeks after PTMC. We conclude that in mitral stenosis, the majority of ventilatory function impairments are caused by hemodynamic alterations that are mainly reversible.

Adult↗
PubMed1990

Polymorphisms detected in actin-related sequences of rats (Rattus norvegicus).

Southern blot hybridization of EcoRI digests of DNAs from 13 rat strains using human cardiac actin gene as a probe revealed polymorphisms in actin-related sequences of rats. EcoRI fragments of 11 kb, 7 kb, 6 kb, 5 kb, 4.5 kb and 4 kb detected in several strains were absent in the remaining strains. The presence of these fragments was suggested to be due to presence of extra sequences homologous to the actin genes, such as processed pseudogenes, in the particular strains. The 13 strains were assigned to each of 7 specific patterns of the polymorphic EcoRI fragments. It was concluded that the polymorphisms of actin-related sequences should be useful for genetic monitoring of laboratory rats.

Actins↗
PubMed1990

[A successfully operated case of tetralogy of Fallot with marked left ventricular dysfunction in adult].

Adults, especially high-aged patients with tetralogy of Fallot (TOF) are said to have a higher operative risk than younger ones because of fragility of their myocardium, bleeding from rich collateral circulation to lungs, and other complications such as brain abscess and endocarditis. It is often difficult to determine the surgical risk for total correction in cases of high-aged patients who have such complications. We report a successfully operated high-aged case of TOF with marked left ventricular dysfunction. A 52-year-old male was referred to our hospital because of exertional dyspnea and cyanosis. He had a history of cerebral embolism and meningitis several months prior to admission. On admission, he was NYHA class 3, and cyanosis and clubbed fingers were present. Cardiac catheterization showed a large VSD, 50% over-riding of the aorta and an infundibular pulmonary stenosis. Right to left shunt was 60% and Qp/Qs was 0.38. The left ventricular end diastolic volume index was 109 ml/m2, slightly larger than normal, and the ejection fraction was only 30%. This left ventricular dysfunction was thought to be caused by fibrosis of the myocardium due to longstanding hypoxemia and hypoxemia itself. There is no previous case report dealing with a successful total correction for a high-aged patient with TOF associated with such a severe left ventricular dysfunction. Congestive heart failure in the post-operative period was successfully treated by catecholamine for two weeks. Postoperative cardiac catheterization showed a small left-to-right shunt, and an improvement of left ventricular ejection fraction from 30% to 38%.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗