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Biomedical subjects

S Nomoto

Publications and source records attributed to S Nomoto.

At least 19 recordsLinked to original sources
PubMed1992

A single-stranded DNA binding protein from mouse tumor cells specifically recognizes the C-rich strand of the (AGG:CCT)n repeats that can alter DNA conformation.

A protein that binds to a synthetic oligonucleotide of (CCT)12 has been purified from Ehrlich ascites tumor cells by a (CCT)12 affinity chromatography. The protein (p70) has an apparent molecular mass of 70 kDa, as assayed by Southwestern analysis. A competition experiment revealed that p70 binds to (CCT)12, (CCCT)8 and (CCTCCCT)6, but not to (CTT)12, (CT)16 and (CCTGCCT)6, suggesting that p70 has a sequence-specificity. The complementary (AGG)12 and the double stranded DNA did not show the binding. It is also confirmed by S1 nuclease analysis that the (AGG:CCT)12 duplex takes a single-stranded conformation in the absence of the protein. This raises a possibility that the duplex forms two single-stranded loops in chromosomes, the C-rich strand being bound to p70. Structural analysis of the resulting (AGG)12 strand by non-denaturing polyacrylamide gel electrophoresis demonstrated the presence of slower and faster migrated conformers in a neutral pH buffer containing 50 mM NaCl at 5 degrees C. The ratio was dependent on the DNA concentration. Both conformers disappeared in the absence of NaCl. This suggests that (AGG)12 can form intra- and inter-molecular complexes by non-Watson-Crick, guanine:guanine base-pairing. The possible biological function of the (AGG:CCT)n duplex and the p70 is discussed.

Animals↗
PubMed1992

A 35-kDa protein binding to a cytosine-rich strand of hypervariable minisatellite DNA.

A minisatellite-binding protein, Msbp-4, with a molecular mass of 35 kDa has been purified from mouse tumor cells that binds to hypervariable Pc-1 and Pc-2 minisatellites. The binding is much more efficient than that to genetically stable minisatellite homologues. As assayed by Southwestern analysis, Msbp-4 favors multiple copies of the Pc-2 repeat sequence GGCAGGA and requires the cytosine-rich single strand for the binding. The activity is also present in extracts from mouse testis but not from liver. The phosphatase treatment revealed that Msbp-4 is phosphorylated and may have a regulatory function, because dephosphorylation affects the activity and specificity of the binding. Sequence preference is demonstrated by a competition experiment using single-base substitution mutants. Thus, the binding properties of Msbp-4 observed here lead to an implication that the protein-DNA complexes result in formation of a single-stranded DNA loop of the G-rich strand in the minisatellite which may enhance the ability of the minisatellite to undergo recombination.

Animals↗
PubMed1992

[False aneurysm formation during the chronic phase of myocardial infarction at the margin of a previously-detected true aneurysm].

The patient was a 59-year-old man who had acute extensive anterior myocardial infarction in October, 1989. One month later, he was transferred to Kyoto University Hospital and underwent cardiac catheterization. Left ventricular aneurysm and significant stenosis in the proximal portion of the left anterior descending artery were documented. Because he experienced chest pain on slight exertion accompanied by a slight increase in the depth of the negative T wave on electrocardiogram, percutaneous transluminal coronary angioplasty (PTCA) was performed. Thereafter, chest pain disappeared, and the patient was discharged. Three months later, he was re-admitted to Kyoto University Hospital for a repeat cardiac catheterization after PTCA. PTCA site was found to be restenosed, and a small diverticulous aneurysm was found at the margin of the previously-detected ventricular aneurysm. As the diverticulous aneurysm was considered likely to precipitate the ventricular aneurysm into rupture, expeditious left ventricular aneurysmectomy was performed to prevent cardiac rupture. Ventricular aneurysms, common complications in myocardial infarction, are of two types, either true or false. Most aneurysms develop during the acute phase of myocardial infarction, and rupture of true aneurysms during the chronic phase of myocardial infarction rarely occurs. However, in the present case, a small diverticulous aneurysm, which was not demonstrated at the initial cardiac catheterization, developed during the chronic phase of myocardial infarction. Pathological examination revealed that the diverticulous aneurysm was a false aneurysm due to incomplete rupture. When the common pathogenesis of ventricular aneurysms in myocardial infarction is considered, the present report might represent an extraordinary rare case.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm, Ruptured↗
PubMed1992

[A case report of successful repair of an aortopulmonary fistula with partial dissection of the pulmonary artery].

We experienced a case of aortopulmonary fistula due to true thoracic aortic aneurysm. Surgical repair was electively performed when we found coexisting pulmonary arterial dissection. Under extracorporeal circulation, dissected flap was excised and the fistula was closed with his own pericardium, and his aortic arch and innominate artery were replaced with a piece of vascular prosthesis. His intra and post operative condition was stable, and postoperative course was uneventful. Prior to this case 13 surgically treated cases had been reported, and 5 had been successful. Among them, only 2 had been electively operated and both successful. Our case is the second case of aortopulmonary fistula associated with pulmonary arterial dissection.

Aortic Dissection↗
PubMed1992

Arterial ketone body ratio during and after cardiopulmonary bypass.

This study is the first to investigate the alteration in hepatic function during and after cardiopulmonary bypass in 30 patients by measuring the arterial ketone body ratio, an index of mitochondrial redox potential (oxidized nicotinamide-adenine dinucleotide/reduced nicotinamide-adenine dinucleotide). Although the preoperative arterial ketone body ratio was within normal limits (1.24 +/- 0.63), it decreased markedly 5 minutes after the start of cardiopulmonary bypass to 0.35 +/- 0.12 and remained at this low level throughout bypass. After bypass it continued to rise in a time-dependent fashion, returning to its preoperative level by the morning of the second postoperative day in normal convalescent patients. However, the ratio recovered more slowly in patients who required prolonged circulatory or respiratory support than in other patients. Thus we suggest that cardiopulmonary bypass had deleterious effects on the hepatic mitochondrial redox potential, which may contribute to homeostatic derangements and metabolic abnormalities.

Aged↗
PubMed1992

[A case of successful repair of aorto-pulmonary artery fistula secondary to aortic arch aneurysm].

A report of a rare case of successful repair of rupture of an aortic aneurysm into the pulmonary artery. A 55-year-old male was transferred to our hospital because of dyspnea with sudden onset, hemoptysis and palpitation. A loud, continuous, "machine-like" murmur was heard on the anterior wall of the chest. Various examinations revealed an acquired shunt between the thoracic aortic aneurysm and the pulmonary artery and high-output heart failure. Aortic arch replacement was performed expeditiously and the patient recovered, and was able to return to work. 108 cases of rupture of a thoracic aortic aneurysm into the pulmonary artery have been reported in the literature. Operation for repair was performed in only thirteen of these. Only four cases have been reported in the literature in which the patients were successfully treated.

Aorta, Thoracic↗
PubMed1991

Cloning of a human cDNA encoding a CDC2-related kinase by complementation of a budding yeast cdc28 mutation.

We have cloned two different human cDNAs that can complement cdc28 mutations of budding yeast Saccharomyces cerevisiae. One corresponds to a gene encoding human p34CDC2 kinase, and the other to a gene (CDK2; cell division kinase) that has not been characterized previously. The CDK2 protein is highly homologous to p34CDC2 kinase (65% identical) and more significantly is homologous to Xenopus Eg1 kinase (89% identical), suggesting that CDK2 is the human homolog of Eg1. The human CDC2 and CDK2 genes were both able to complement the inviability of a null allele of S. cerevisiae CDC28. This result indicates that the CDK2 protein has a biological activity closely related to the CDC28 and p34CDC2 kinases. However, CDK2 was unable to complement cdc2 mutants in fission yeast Schizosaccharomyces pombe under the condition where the human CDC2 gene could complement them. CDK2 mRNA appeared late in G1 or in early S phase, slightly before CDC2 mRNA, after growth stimulation in normal human fibroblast cells. These results suggest that in human cells, two different CDC2-like kinases may regulate the cell cycle at distinct stages.

Alleles↗
PubMed1991

SGV1 encodes a CDC28/cdc2-related kinase required for a G alpha subunit-mediated adaptive response to pheromone in S. cerevisiae.

The GPA1 gene of S. cerevisiae encodes a G alpha subunit that plays a positive role in the transduction of signals stimulating recovery from pheromone-induced cell cycle arrest. The GPA1Val50 mutation, in which Gly-50 is replaced by valine, causes hyperadaptation to pheromone. However, GPA1Val50 cells do not recover from division arrest in the absence of both CLN1 and CLN3, which encode G1 cyclins, indicating that the recovery-promoting activity of GPA1Val50 requires the function of G1 cyclins. An sgv1 mutation suppresses the hyperadaptive response caused by GPA1Val50 and also confers cold- and temperature-sensitive growth. The SGV1 gene encodes an apparent protein kinase homologous to CDC28/cdc2 kinase: SGV1 is 42% identical to CDC28. The activated mutation, CLN3-2, partially suppresses the growth defect of sgv1, suggesting that the SGV1 and CLN3 proteins may act in the same growth control pathway.

Amino Acid Sequence↗
PubMed1991

Hemodynamic assessment of radial-arterial pressure-wave contours in children.

A new classification system for the radial-arterial pressure-wave contour in children is proposed with respect to their hemodynamic parameters. The contour of the radial-arterial pressure wave was analyzed in 45 children who had undergone open heart surgery. Stroke volume and peripheral vascular resistance were calculated from the cardiac output by thermodilution. The arterial pressure-wave contours were classified into type I, II or III, with each wave type having three, two and one shoulders, respectively. Type I denoted a better cardiac index, with a lower heart rate and larger stroke volume than type II. Type III was symptomatic of low cardiac output. Type I was further classified into subgroups Ia and Ib according to the magnitude of the tidal wave, and type II was subdivided into IIa and IIb according to the magnitude of the dicrotic notch. The classification of subgroup types a and b in both types I and II was related to the degree of vascular contraction. It is concluded that monitoring of the arterial pressure-wave contours provides useful information regarding hemodynamics in children.

Blood Pressure↗
PubMed1991

Expression of three cell proliferation-associated antigens, DNA polymerase alpha, Ki-67 antigen and transferrin receptor in nodal and cutaneous T-cell lymphomas.

We studied the expression of three cell proliferation-associated antigens: DNA polymerase alpha, Ki-67 antigen, and transferrin receptor, in 35 T-cell lymphomas of nodal origin (T-NL) and 40 cutaneous T-cell lymphomas (CTCL). Immunohistochemical staining was carried out on frozen tissue sections of these specimens using three monoclonal antibodies, DAKO-PC, CL22-2-42B (DNA polymerase alpha), and OKT9. The proportion of cells positive for CL22-2-42B, DAKO-PC, or OKT9 among all tumor cells was correlated with four histologic subtypes: malignant lymphoma (ML), diffuse, small; mixed; large; and large cell immunoblastic in both T-NL and CTCL. A strong correlation was noted between positivity for CL22-2-42B and that for DAKO-PC or OKT9. On the other hand, no difference in the expression of these three antigens was noted between T-NL and CTCL in the high, intermediate or low grade-malignancy group. In CTCL as well as in T-NL, cells positive for CL22-2-42B, DAKO-PC or OKT9 were significantly more numerous in the high-grade group than the intermediate-grade group, and in the intermediate-grade group than the low-grade group. Furthermore, a significant correlation between survival period and the number of CL22-2-42B-positive cells was noted when the T cell malignancies, CTCL and T-NL were considered (t value = 2.015, p less than 0.05). Thus, the expression of DNA-polymerase alpha, Ki-67 antigen or OKT9 seems to well reflect the biological behavior and/or clinical prognosis of T-cell lymphoma.

Antibodies, Monoclonal↗
PubMed1991

[Doppler echographic evaluation of pressure gradients of Björk-Shiley valve in the aortic position at rest and with exercise].

Pressure gradient across the Björk-Shiley (B-S) valve in the aortic position was assessed by Doppler echocardiography at rest and with exercise. There was close correlation between peak pressure gradient and area index which is a ratio of geometric orifice area (cm2) to body surface area (BSA) (m2). The correlation coefficient was -0.70 at rest and -0.86 with exercise. High peak pressure gradients with exercise were observed in the patients with 19 mm size (71 mmHg) and 21 mm size (107 mmHg). To avoid residual left ventricular outflow obstruction with exercise, it is considered advisable to use a #19 B-S valve in patients with BSA smaller than 1.1 m2, a #21 B-S valve in patients with BSA smaller than 1.4 m2, a #23 B-S valve in patients with BSA smaller than 1.8 m2, and a #25 B-S valve in patients with BSA smaller than 2.3 m2. If proper size of B-S valve cannot be inserted, aortic or aortic-mitral patch annuloplasty or the use of bileaflet valve are recommended as procedures of choice for small aortic annulus.

Aortic Valve↗
PubMed1990

Regulation of the yeast pheromone response pathway by G protein subunits.

The yeast GPA1, STE4, and STE18 genes encode proteins homologous to the respective alpha, beta and gamma subunits of the mammalian G protein complex which appears to mediate the response to mating pheromones. Overexpression of the STE4 protein by the galactose-inducible GAL1 promoter caused activation of the pheromone response pathway which resulted in cell-cycle arrest in late G1 phase and induction of the FUS1 gene expression, thereby suppressing the sterility of the receptor-less mutant delta ste2. Disruption of STE18, in turn, suppressed activation of the pheromone response induced by overexpression of STE4, suggesting that the STE18 product is required for the STE4 action. However, overexpression of both the STE4 and STE18 proteins did not generate a stronger pheromone response than overexpression of STE4 in the presence of wild-type levels of STE18. These results suggest that the beta subunit is the limiting component for the pheromone response and support the idea that beta and gamma subunits act as a positive regulator. Furthermore, overexpression of GPA1 prevented cell-cycle arrest but not FUS1 induction mediated by overexpression of STE4. This implies that the alpha subunit acts as a negative regulator presumably through interacting with beta and gamma subunits in the mating pheromone signaling pathway.

Amino Acid Sequence↗
PubMed1990

[Problems in patients with use of a ventricular assist device].

The purpose of the present study was to review the results obtained in patients with a ventricular assist devices (VAD) in our hospital, and to discuss various problems concerning a VAD use, such as indications, right ventricular failure, and evaluation of cardiac function. Fourteen VADs were applied to 11 patients for left ventricular assist, including two for right ventricular assist and for one as biventricular assist with a VAD in the left and a biopump in the right. The clinical diagnoses of the patients were as follows: 10 ischemic heart disease, two valvular disease, one acute aortic dissection, and one corrected transposition of the great arteries. VADs were indicated in 11 patients because of difficulty in weaning from cardiopulmonary bypass (CPB), and in three patients because of cardiogenic shock after discontinuing CPB. Among the 14 patients, 11 had an effective VAD, six were successfully weaned from a VAD, and two survived. The VAD was ineffective due to uncontrollable bleeding and improper indications for the device, as in applying a one-sided heart assist when a biventricular assist was necessary. In spite of an effective VAD, five patients could not be weaned from VAD because of brain damage, sepsis, and hypoxia. After removing a VAD, four patients died; one due to mediastinitis, two due to respiratory failure, and one due to low output syndrome. All the four patients had renal failure followed by multi-organ failure finally, because of prolonged CPB time. The CPB time was shorter among the long survivors than in others. Cardiac function during assist and the weaning probability from a VAD were evaluated not only by the so-called on-off test, but also by transesophageal Doppler echocardiography. Ventricular wall motion and pulmonary venous flow pattern were analyzed by transesophageal Doppler echocardiography. The pattern of monophasic forward flow in the pulmonary vein was associated with reduced wall motion during deteriorated cardiac function, while the flow pattern became biphasic as cardiac function recovered. From these results, we concluded as follows: 1. Early decisions as to whether VAD is indicated are important. 2. A right VAD should be considered in cases with biventricular failure, during left ventricular assist, if right atrial pressures elevated more than 18 mmHg constantly. 3. The evaluation of cardiac function by transesophageal Doppler echocardiography is useful for making decisions as to wean patients from a VAD.

Adolescent↗
PubMed1990

[A leiomyosarcoma of the jejunum diagnosed by an ultrasonically guided percutaneous biopsy].

Reported is a leiomyosarcoma of jejunum that was found in a 61-year-old man who was admitted to our clinic because of an abdominal distension. A CT scan and an ultrasonic examination revealed a giant tumor with a central necrosis in the abdominal cavity. A study of barium that was ingested revealed an elevated lesion without a fistel formation in the jejunum about 25 cm distant from the Treitz ligament. An ultrasonic the guided percutaneous biopsy was done and pathological diagnosis indicated a leiomyosaroma. Surgery was performed on June 16 1989 and the tumor weighing 4,934 g and 30 x 25 x 18 cm in size, was completely resected.

Biopsy, Needle↗
PubMed1990

[Changes in the immune response in postoperative patients while running the ventricular assist device (VAD)].

We examined the immunological parameters in two patients who were assisted with LVAD in postoperative LOS. Both patients demonstrated transient consumption of complements immediately after running the LVAD. The serum concentrations of immunoglobulins (IgG, IgM, IgA) showed no significant decrease. Both patients had significant postoperative lymphopenia, but recovered in a week. A decrease in the number of T cells was observed in both patients. The OKT4/OKT8 ratio initially increased in one patient, but gradually declined postoperatively. In the other patient, the OKT4/OKT8 ratio decreased. The lymphocyte response to mitogen (PHA) remained significantly depressed when the number of lymphocytes returned to the normal level, suggesting that the lymphocytes were functionally impaired. Such findings are generally observed after cardiac surgery. Thus, LVAD does not affect the immune response.

Adolescent↗
PubMed1989

[Setting characteristics of calcia-bonded investments by hydration].

Calcium oxide (CaO) slurry mixed with water hardens and expands by hydration. The authors used this setting characteristic as a binder of zirconia-refractory investments. If a mixed slurry was placed in air, unreacted residual calcia powders absorbed water and reverted to calcium hydroxide (Ca (OH)2). This resulted in a large setting expansion that continued for several days. A carbon dioxide (CO2) gas atmosphere controlled this expansion of calcia. When mixed slurry was placed in a carbon dioxide gas atmosphere, calcium carbonate (CaCO3) was formed and prevented the further hydration of unreacted calcium oxide. Thus setting expansion values were controlled. The combined expansion of setting and thermal expansion, in CaO-CO2-bonded zirconia investments, was about 1.5-2.5%. On the whole, calcium oxide is expected to be a good binder for high temperature dental casting refractory.

Calcium↗