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Biomedical subjects

M Yamaguchi

Publications and source records attributed to M Yamaguchi.

At least 1,423 records · Page 79Linked to original sources
PubMed1988

Assignment of the human cytochrome c1 gene to chromosome 8.

We previously isolated a cDNA clone for human cytochrome c1. The insert DNA of approximately 950 bp from this clone was used as a probe to identify the cytochrome c1 gene. High molecular weight DNAs extracted from a panel of 14 independent human-mouse somatic cell hybrids were digested with BamHI and analyzed by Southern blot hybridization. The results indicated that the gene for human cytochrome c1 is located on chromosome 8.

Animals↗
PubMed1988

Electron microscopy of hepatitis B virus core antigen expressing yeast cells by freeze-substitution fixation.

We have used the freeze-substitution fixation technique for electron microscopy of yeast cells that express the hepatitis B virus core antigen (HBcAg) following transformation with the cloned gene. Abundant spherical particles were found within the transformed cells. These particles had a uniform size and shape, measured about 21 nm in diameter, had electron-lucent centers, and consisted of many subunits. They were localized in both the cytoplasm and the nucleus. None of these particles was found in the cells of the parent strain. Comparison of the HBcAg particles isolated from the yeast cells and the particles within the yeast cells demonstrated that the 21-nm particles were in fact ultrastructurally superimposable on HBcAg. Thus, the HBcAg particles within the yeast cells were similar to the HBcAg particles in human liver tissues infected with hepatitis B virus, not only in their size and appearance, but also in their intracellular localization. These results suggest that the yeast cell has the same machinery for synthesis and intracellular translocation of the HBcAg polypeptides as the human cell.

Animals↗
PubMed1988

Unique mechanism of action of an antifungal antibiotic RI-331.

An amino acid antibiotic RI-331, (S)-2-amino-5-hydroxy-4-oxopentanoic acid, produced by a Streptomyces sp., is a novel antifungal agent. Biochemical studies on the mechanism of action of the antibiotic were carried out with a susceptible yeast Saccharomyces cerevisiae. In growing yeast cells, RI-331 inhibited protein synthesis to a greater extent than RNA or DNA synthesis. However, polypeptide synthesis by a cell-free preparation from yeasts was refractory to the antibiotic. The inhibition of protein synthesis by RI-331 was revealed to be due to the depletion of several amino acids such as threonine, methionine, isoleucine and serine in the cellular pool. These results suggest the possibility that some steps in amino acid metabolic pathways, especially those involved in biosynthesis of threonine, methionine and isoleucine, may constitute a primary target of RI-331 action.

Amino Acids↗
PubMed1988

[Congenital heart disease: diagnostic approaches, surgical indications and operative results].

Our management policies of the main congenital cardiac defects which require emergency surgical intervention in neonate and infancy were reported. Total anomalous pulmonary venous drainage (TAPVD): Recent refinements in two-dimensional (2-D) echocardiography have made it possible to operate for this anomaly using only this modality. When a combination of coarctation is suspected and/or the location of the drainage of the pulmonary vein is obscure, catheterization and angiocardiography are added for detailed diagnosis. It is, however, our policy not to perform right-sided angiocardiography for patients younger than three months of age. Symptomatic cases are operated urgently, although not always on an emergency basis. In our experience, a 12 approximately 24 hour delay with intensive cardiorespiratory and metabolic care may improve the preoperative conditions considerably and increase the chances of a successful surgical repair. Coarctation of the aorta (CoA) and interruption of the aortic arch (IAA): Diagnosis of CoA by echocardiography and aortography by radial artery injection is well established. In neonates and infants with CoA or CoA + patent ductus arteriosus (PDA) and/or ventricular septal defect (VSD), emergency repair of coarctation (usually with subclavian flap aortoplasty) without pulmonary artery banding (PAB) is undertaken on the day of established diagnosis. If a combination of complex cardiac anomalies such as transposition of the great arteries (TGA) and Taussig-Bing anomaly is suspected, catheterization and angiocardiography are added for the detailed diagnosis. Repair of coarctation combined with PAB has been our choice of procedure in these infants. If IAA is suspected, catheterizaton, angiographic and detailed echocardigraphic studies are performed to define the precise anatomy of the aortic arch and associated intracardiac lesions, paying particular attention to the left ventricular outflow tract, as soon as such patients become clinically stable by intensive medical treatment using prostaglandin E1 (PGE1), digitalis and diuretics. Once the diagnosis is established surgical treatment should be carried out without delay. Initial palliation by aortic arch reconstruction with PAB followed by two-stage definitive intracardiac repair have been our choice of procedure in neonates and infants with IAA without severe left ventricular outflow tract obstruction.(ABSTRACT TRUNCATED AT 400 WORDS)

Cardiac Catheterization↗
PubMed1988

Genetic analysis of systemic lupus erythematosus: 1. Detection of disease-associated variant proteins by two-dimensional gel electrophoresis.

Various genetic studies indicate that development of systemic lupus erythematosus (SLE) is regulated by the mode of multifactorial inheritance, i.e., by the overall effect of polygenes and environmental factors. To elucidate some variant genes involved in the polygenic system responsible for onset of SLE, we resolved and measured the protein components of lymphocytes and sera from inactive-SLE patients, their relatives, and normal controls, using two-dimensional gel electrophoresis. Intercomparison of polypeptide patterns between patients and controls revealed three major variations, two detected in lymphocytes and one in sera. These variations were present in 66-82% of the patients, in 20-36% of the control group, and in 41-64% of the relatives. In addition, nearly half of SLE patients, but only one of 19 normal controls, possessed all three SLE-associated traits, suggesting that these variant proteins may reflect in part the genetic factors contributing to development of SLE.

Adolescent↗
PubMed1988

Still's disease associated with necrotizing lymphadenitis (Kikuchi's disease): report of 3 cases.

Necrotizing lymphadenitis (Kikuchi's disease) is recognized as one of the benign lymphadenopathies. Previously, this condition has not been described in Still's disease which is frequently associated with lymphadenopathy. We report 3 cases of Still's disease, 2 in adults and 1 in an older child, with the findings of necrotizing lymphadenitis on lymph node biopsy. Considering the common infectious and/or immunologic etiologies described in both disorders, coexistence of both conditions suggests the possibility that they share a common etiology.

Adolescent↗