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Biomedical subjects

Ryozo Okada

Publications and source records attributed to Ryozo Okada.

5 recordsLinked to original sources
PubMed2006

A passive smoking screening program for children.

BACKGROUND: There has been no report to date on mass screening of passive smoking in children using biomarkers. METHOD: To identify children exposed to actual environmental tobacco smoke (ETS), 261 children were divided into the following 3 groups: (A) both parents smoke; (B) one parent smokes; and (C) no parent smokes. Child urinary cotinine measurement and a parent questionnaire were obtained. RESULTS: Urinary cotinine was positive (>10 ng/ml) in 92 (35.2%) of the 261 children. Of the 92 children, 29 were classified into group A, 47 into group B, and 16 into group C. The percentages of children who tested positive for urinary cotinine in groups A, B, and C were 56.9%, 31.1%, and 27.1%, respectively. However, in group B, the percentage of children who tested positive for urinary cotinine was significantly higher if only the mother smoked (47.1%) than if only the father smoked (29.1%) (P<0.05). The mean+SD urinary cotinine level in group A was 12.9+/-6.5 ng/ml, and that in group B was 10.4+/-3.8 ng/ml if the mother smoked and 5.4+/-2.6 ng/ml if the father smoked. CONCLUSIONS: This smoking screening program may be useful in identifying children with actual ETS exposure and motivating their parents to either quit smoking or modify their smoking behavior around children.

Adult↗
PubMed2005

Histopathological findings of the no-reflow phenomenon following coronary intervention for acute coronary syndrome.

Although no-reflow phenomenon may occur in patients that experience reperfusion after ischemia, there have been no reports describing the postmortem findings in these patients. We describe the findings of an autopsy in a 56-year-old man who experienced acute coronary syndrome with no-reflow phenomenon after coronary intervention. Macroscopic study demonstrated myocardial infarction with diffuse hemorrhage, and microscopic analysis revealed vascular damage and microembolization in the no-reflow area. In conclusion, coronary microembolization and damage to the small coronary artery may contribute to the pathogenesis of no-reflow phenomenon following coronary intervention in humans.

Angioplasty, Balloon, Coronary↗
PubMed2003

Histological study on the distribution of autonomic nerves in the human heart.

To investigate the distribution of autonomic nerves in the human heart, six autopsied hearts without cardiovascular disease were studied by a histochemical method for acetylcholinesterase (AChE) and by an immunohistochemical method for tyrosine hydroxylase (TH). The density of nerve distribution was microscopically calculated by the point-counting method to evaluate regional distribution of the autonomic nerves. There were more AChE-positive nerves and TH-positive nerves in the atrium than in the ventricle, and more at the base than at the apex in the ventricle. There were more AChE-positive nerves in the subendocardial area than in the subepicardial area of the myocardium. In the atrium, AChE-positive nerves were more numerous than TH-positive nerves. On the other hand, there were more TH-positive nerves than AChE-positive nerves in the ventricle. Predominancy of the distribution density at the anterior to the posterior wall of the ventricle was observed for TH-positive nerves. The different distribution patterns of sympathetic and parasympathetic nerves could modify cardiac performance under both physiologic and pathologic conditions.

Acetylcholinesterase↗
PubMed2003

Tumorous deformity of mitral valve leaflet after chordal rupture in a child.

A case with tumorous deformity of the posterior mitral valve leaflet after spontaneous chordal rupture in a child is described. A partial rupture in the chordae tendineae of the posterior mitral leaflet was found by echocardiography in a 9-year-old Japanese boy. Tumorous bulging was gradually developed in the leaflet and was surgically excised 5 years later. Multiple nodular tumors were found on the atrial surface of the posterior mitral leaflet. Histological examination revealed that the tumorous bulging consisted of myxomatous materials in which collagen fibrils and very fine elastic fibers were distributed loosely and irregularly. Normal-looking endothelial cells covered the luminal surface of the bulging lesion. Vimentin-positive spindle-shaped mesenchymal cells were scattered in the bulge area. The labeling index of proliferating cell nuclear antigen (PCNA) in these cells was 29.3%. These spindle cells were positive for matrix metalloproteinase (MMP)-1 in the entire bulge area. The cells and matrix were positive for MMP-2 and tissue inhibitor of MMP (TIMP)-1 in the basal area of bulging, but were weakly positive or negative at the surface area. Reactivity for TIMP-2 in the cells in the bulge area was obviously weaker than that in the cells at the spongiosa of the anterior mitral leaflet, which was obtained from the patient at the valve replacement operation 9 months after the initial operation. These findings indicated that the tumorous deformity of the mitral valve was formed by the overgrowth of valve tissue under the stimulation of mitral regurgitation in this child, and the imbalance of MMP and TIMP might play an important role in the bulge formation.

Biomarkers, Tumor↗