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Biomedical subjects

I Sakurai

Publications and source records attributed to I Sakurai.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Current alteration of Helicobacter pylori in gastro-duodenal diseases].

The current alteration of the detection rate of Helicobacter pylori (H. pylori) on mucous membranes of the stomach has been surveyed and reviewed for 49 cases of gastro-duodenal diseases. The survey has been conducted for 3 years and an endoscopic examinations have been performed 2-8 times. On the first visit, the diagnosis can be made endoscopically, and H2 blockers and another agents were used as therapeutic drugs. The detection rate was 67.3% (33 cases) for positive cases and positive reaction cases, while the rate was 32.6% (16 cases) in negative cases and negative reaction cases. Among them, the most commonly observed disease was atrophic gastritis, followed by duodenal ulcer, and acute gastric mucous lesions (AGML). Peptic ulcer was not seen. After administration of H2 blockers and anti-ulcer agents, the H. pylori-detection rate was found to fluctuate according to the diseases and alterations in the morbidity period. Some cases indicated the disappearance of H. pylori in accordance with the improvement of the lesion site.

Adult↗
PubMed1992

Intimal cell population and location in arteries of Japanese children and youth.

It seems important to study initial changes in any sort of disease to elucidate its pathologenesis. Arterial atherosclerosis varies in its severity and extent between each artery. By macroscopic and immunocytochemical studies on aortas and coronary arteries of young Japanese people, the following results were obtained. Fatty streaks are more frequently discovered in aortas than in coronary arteries, while coronary arteries tend to disclose a higher frequency of diffuse intimal thickening with more smooth muscle cells and fewer macrophages. But there is not much difference in frequency of fibrous plaques between the two arteries. Lesions of localized elevation appear to have many more macrophages in coronary arteries. There must be significant structural and functional differences in the "normal" state between aortas and coronary arteries, which may suggest that it is necessary to pay attention to the characteristics specific to each artery in studying the pathogenesis of atherosclerosis.

Adolescent↗
PubMed1992

Diet-induced atherosclerosis in cynomolgus monkey aorta and regression by the sixth-month observation.

Pathomorphologic analysis was employed to evaluate diet-induced atherosclerosis in cynomolgus monkey aorta and regression by administration of a hypolipidemic agent for six months after the atherogenic ration. Twenty-seven male cynomolgus monkeys were divided into three groups. Group A was fed individually with a high-fat diet containing 0.3% cholesterol under identical conditions for six months. Group B was fed with normal monkey chow for six months after the same atherogenic ration. Group C was fed with normal monkey chow and administered a hypolipidemic agent 1% of 4-[2-(4-isopropylbenzamido)ethoxy] benzonic acid for six months after the same atherogenic ration. Each thoracic and abdominal aorta of animal models was separately analyzed. Lipid composition analysis and esterified cholesterol (CE) in aortic wall, ratio of free cholesterol to phospholipid, surface involvement, and atherosclerotic index after Sudan IV staining were studied for evaluation of progression and regression. The configurations of atherosclerotic involvement were histologically evaluated among each group. These observed lesions, features specific to cynomolgus lesions, mainly consisted of lipid-rich foam cells, lipid debris, and proliferated extracellular matrix. No different lesion composition was noted between the thoracic and abdominal aorta. This may suggest that some local factors play an important role for development of atherosclerosis after the initial event. Group C had remarkable reduction of foam cells and of CE accumulation in both the thoracic and abdominal aortic wall. Accelerated regression in group C as compared with group B was demonstrated both biochemically and pathohistologically. These results suggest that substantial regression of atherosclerosis in both the thoracic and abdominal aorta can be expected. This hypolipidemic agent exerts notable antiatherosclerotic activity, along with a lowering effect on plasma total cholesterol levels.

Animals↗
PubMed1992

[Argyrophilic nucleolar organizer region proteins (Ag-NORs) in human central nervous tumors].

A silver colloid staining technique for identifying nucleolar organizer region-associated proteins (Ag-NORs) was applied to 17 primary gliomas and 16 meningiomas. These comprised 8 glioblastomas, one pleomorphic xanthoastrocytoma, 8 benign astrocytoma, 10 nonrecurrent meningiomas and 6 recurrent meningiomas, in which the mean number of Ag-NORs' per nuclei, were 3.37, 2.34, 2.57, 2.16 and 2.80 respectively, identifying significant differences among these groups. Ag-NORs of four giant cell glioblastomas showed low numbers of Ag-NORs, suggesting better prognosis. In spite of the time consuming and complicated counting method Ag-NORs is reproductive and useful as a tool for estimating the proliferating potential of various brain tumors, and appears to widely applicable in clinical laboratories.

Adolescent↗
PubMed1992

[A study of intraoperative rapid frozen section diagnosis focusing on accuracy and quality assessment].

Accuracy of frozen section (FS) diagnoses was investigated in a consecutive series of 1129 intraoperative consultations. In our series, the correct diagnosis including clinically not serious minor errors was made in 96.9% of the cases. Whereas the accuracy ratio of FS diagnosis for unknown pathologic process decreased to 92.2%. Among all the types of tissues, central nervous system was shown to be the most frequently handled for FS, followed by lung/bronchus, breast, liver/biliary tract, lymph node and so forth. The requesting ratio of FS, on the other hand, tended to be high in the following specialties; neurosurgery (46.5%), thoracic surgery (19.0%), general surgery, (10.0%). Deferred diagnosis with a provisional diagnosis and misinterpretations in histology typing without serious clinical problem accounted for 2.7% and 3.1% respectively. Causes of erroneous diagnoses seemed to be multifactorial, such as inappropriate sampling, diagnosis on poor quality histology sections, lack of clinical information, lack of enough experience in FS practice of pathologists, or a combination of more than two of them, though inevitable cases showing minimal cytological and structural atypia were included. Intraoperative consultation by FS diagnosis is now essential to serve a good quality medication to patients. It is thus necessary that to establish a tight peer review system and also to provide an education program with regard to practice in FS diagnosis particularly for young pathologists.

Frozen Sections↗
PubMed1992

Recovery of endothelium-dependent responses by reseeding endothelial cells in culture onto the denuded coronary artery.

Endothelium-denuded coronary artery was reseeded with the endothelial cells in culture, and the endothelium-dependent responses were compared with those in arteries with or without native endothelium. A23187 produced a relaxation in the arterial preparations reseeded with cultured endothelial cells in the cell suspension of 10(5) cells/ml for 17 to 19 hr, whereas no relaxation was observed in the denuded artery. Relaxing response to Ca++ ionophore A23187 was dependent on the number of endothelial cells reseeded. The A23187-induced relaxation in the cell-reseeded artery was inhibited markedly by pretreatment with 3 x 10(-4) M NG-monomethyl-L-arginine or 5 x 10(-5) M methylene blue, but not 10(-4) M aspirin. NG-monomethyl-L-arginine (3 x 10(-4) M) and methylene blue (5 x 10(-5) M) produced a contraction in the cell-reseeded artery. Contraction evoked by bradykinin in the denuded arteries was attenuated by reseeding endothelial cells. KCl-induced contraction in the endothelium-reseeded artery did not differ from that in the denuded artery. Contractile responses to norepinephrine and serotonin were attenuated by reseeding endothelial cells onto the denuded artery to a small extent. Scanning electron microscopy showed that the luminal surface of endothelium-reseeded arteries was partly covered with endothelial cells. We conclude that when the cultured endothelial cells are reseeded onto a denuded coronary artery, endothelium-derived relaxing factor release occurs, but endothelium-dependent mechanisms are not the same as those for native cells.

Animals↗
PubMed1991

Coronary artery spasm and vascular biology. Cholinergic constriction.

Coronary artery spasm is undoubtedly one of the causative factors of ischemic heart disease, particularly variant-type angina pectoris and myocardial infarction, but the disease mechanisms involved are still unclear. The present review describes the clinical background of coronary artery spasm in relation to ischemic heart disease, including a brief history of studies in this field, and also suggests future guidelines for experimental investigations based on the characteristics of coronary artery spasm, focusing particularly on data we have obtained in our laboratory from studies of cholinergic constriction. The pig may be a suitable animal in which coronary artery spasm could be provoked with cholinergic agents following endothelial denudation. The use of such large animals would allow the study of spastic arterial segments by various methods with angiographic confirmation. After endothelial denudation it is possible that phenotypic changes in cholinergic receptors might occur in smooth muscle cells, and that such changes might remain even after endothelial repair.

Acetylcholine↗
PubMed1991

Primary osteosarcoma of the ovary. A case report.

A case of primary osteosarcoma arising in the left ovary of a 75-year-old female is described. The chief complaint was a sensation of lower abdominal mass. An abdominal plain film showed a large calcified mass in pelvic region, and a preoperative diagnosis of "ovarian fibroma" was made. The excised tumor was divided into 4 pieces, resembling an oyster shell. Microscopically, the tumor fragments were composed of compact bone or woven bone with surrounding atypical osteoblasts and osteoclasts. The tumor was partly composed of numerous spindle cells with malignant osteoid or atypical chondroid formation, and diagnosed as "osteosarcoma". The cystic part of the lesion was lined with a single layer of columnar cells, but the tumor contained no other germ elements or stem cells, or malignant epithelium. Therefore, it is doubtful that this tumor originated from teratoma or malignant mixed mesodermal tumor, and we conclude that this ovarian osteosarcoma arose through a neoplastic change in ovarian stromal cells. The patient died 4 months after surgery due to intra-abdominal and intrathoracic dissemination of the tumor.

Aged↗
PubMed1991

The effect of apomorphine on operant behavior in rats under normoxic and hypoxic conditions.

We studied the effect of apomorphine on the performance of rats, maintained on a free-operant shock-avoidance schedule under normoxic and hypoxic (12, 10, and 8% O2) environments. In a normoxic environment, apomorphine (1, 2, 4, and 8 mg/kg, i.p.) produced stereotyped behaviors and dose-dependent increases in the rats' lever-pressing response rate. In a hypoxic environment, however, the increase of the response rate induced by apomorphine at 1 mg/kg was suppressed by the hypoxic conditions tested. At a dose of 8 mg/kg apomorphine, it was also suppressed by exposure to severe hypoxia (10 and 8% O2). These results suggest that the impairment of avoidance behavior in rats by hypoxia was not always improved by apomorphine, and that the degree of improvement depends on the combined effects of the dosage of the drug injected, the degree of hypoxia, and the type of behavior observed.

Animals↗
PubMed1990

Immuno-light and electron microscopic features of chronic hepatitis D.

A morphologic study with immunohistochemical detection of the viral antigens of hepatitis B and Delta was performed on 36 liver specimens from patients with delta positive chronic viral hepatitis B. Electron microscopy was performed in 9 cases. No light microscopic or ultrastructural features specific for hepatitis D were observed. Lymphocytic infiltration occurred more often close to hepatocytes containing either hepatitis Delta antigen or hepatitis B core antigen in the cytoplasm, suggesting an involvement of cellular immune mechanisms in chronic hepatitis D as well as in hepatitis B. The simultaneous expression of both HBcAg and Delta antigen in occasional specimens over longer time periods indicates the possible co-existence of both viruses without mutual inhibition.

Antigens, Viral↗
PubMed1990

Bacterial Accumulation of Metallic Compounds.

Xanthomonas maltophilia accumulated metals or metallic compounds within the cell in the form of one or a few particles, in a peculiar condition similar to that of an electrolyte solution in an electric cell. The particles consisted of many little granules, most of which were assumed to be composed mainly of a compound of zinc and phosphorus in an amorphous state.

Journal Article↗
PubMed1990

Effect of carnitine on size limitation of experimental myocardial infarct.

To elucidate 1-carnitine chloride effects ischemic myocardium for the possibility of a salvage of risk zone around necrosis in myocardial infarcts of dogs, a quantitative evaluation of the extent of myocardial infarcts was done by size detection with use of monastral blue and tissue dehydrogenase histochemistry at 20 hours after coronary ligation. The results show that the ratio of unsalvaged infarct zone to occluded coronary bed is 85.3 +/- 2.9% in the control group, while it is 53.2 +/- 3.6% in the 1-carnitine administered (1 C) group. The difference between these ratios is statistically significant (p less than 0.01). The results also indicate significantly lower serum CPK concentration. Therefore, carnitine may play a role in preventing a size extention of infarcts through improving an altered lipid metabolism, particularly a fatty acid metabolism, of myocardial cells in the risk zone.

Animals↗
PubMed1990

[Application of crush cytology preparation for rapid diagnosis of brain tumors].

The crush cytology perform during the surgery for 22 cases with brain tumors at Surugadai Nihon University Hospital, being compared with frozen and permanent histology sections. Crush cytology, which was generally and less damaged by artefacts than frozen sections. Immunocytochemistry used crush cytology were useful tools for differential diagnosis between undifferentiated glioma and carcinoma. Crush cytology were thought to be useful using together with the frozen sections for intraoperative diagnosis.

Brain Neoplasms↗
PubMed1988

A nation-wide study of atherosclerosis in infants, children and young adults in Japan.

This paper reports the results of a nation-wide cooperative study of atherosclerosis in young, first generation Japanese with ages ranging from 1 month to 39 years, who were autopsied between 1978 and 1982 in hospitals distributed over the entire archipelago of Japan. Atherosclerotic lesions in 2320 aortas, 1620 coronary arteries and 344 cerebral arteries were classified into fatty streaks, fibrous plaques and complicated lesions and were then quantificated with the point-counting method. Atherosclerosis of aortas, coronary arteries and cerebral arteries, determined by surface involvement (SI) of atherosclerotic lesions and atherosclerotic index (AI), increased with age; the severest were seen in aortas, and then, with decreasing severity, in the coronary and cerebral arteries. Fatty streaks preceded the other lesions and accounted for the largest portion of the lesions in aortas and coronary arteries. Fibrous plaques and complicated lesions developed in the later decades of life. The patients with collagen diseases had a greater severity of aortic atherosclerosis in the 2nd and 3rd decades of life, than those without such disorders. Correlation of antemortem clinical data with SI and AI of each artery were analyzed, using simple correlation analysis and multiple regression analysis. Age, serum cholesterol and blood pressure were significantly and positively correlated with SI and AI of aortas and coronary arteries. Serum cholesterol was more strongly correlated with the extent of fatty streaks than was mean blood pressure and vice versa with that of fibrous plaques. Atherosclerosis of cerebral arteries, however, showed a significant correlation only with the factor of mean blood pressure. Therefore the susceptibility to risk factors varies with the artery in cases of early lesions of atherosclerosis in young Japanese.

Adolescent↗
PubMed1988

An immunohistochemical study of neovasculature in human brain tumors.

In order to elucidate the characteristics of newly-formed small blood vessels in brain tumors, 51 cases of various types of brain tumor were studied immunohistochemically. Endothelial cells in all tumor types reacted positively with anti-Factor VIII-related antigen (F-VIII Ag) and UEA-1. Reactivity to UEA-1 was limited to endothelial cytoplasm. Proliferating immature endothelial cells showed weak reactivity to anti-F-VIII Ag. In some cases of benign tumors diffuse reactivity to anti-F-VIII Ag was noted throughout thickened medial areas of the vascular walls, in which reactivity to anti-fibrous collagen and anti-fibronectin was noted. UEA-1 was thought to be a more specific endothelial marker than F-VIII Ag, especially for proliferating and immature endothelial cells. It is strongly suspected that fibrous collagens are related to the formation of a thickened vascular wall in newly-formed small tumor vessels.

Adolescent↗