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Biomedical subjects

M Yasuda

Publications and source records attributed to M Yasuda.

At least 415 records · Page 23Linked to original sources
PubMed1989

[Role of polymorphonuclear leukocytes and oxygen-derived free radicals in the formation of gastric mucosal lesions induced by platelet-activating factor].

Gastric hemorrhagic erosions were induced by the administration of platelet-activating factor (PAF). Gastric wall blood flow was decreased and thiobarbituric acid (TBA) reactants in the gastric mucosa were increased 10 min after PAF injection. SOD and catalase reduced gastric mucosal lesions and TBA reactants, but had no influence on gastric blood flow. In polymorphonuclear leukocytes (PMN)-depleted rats, gastric mucosal lesions and TBA reactants in the gastric mucosa were reduced and gastric blood flow were increased. PAF induced the superoxide production from rat PMN in a dose dependent manner. These results suggest that oxygen-derived free radicals produced by PMN and lipid peroxidation may play an important role in the pathogenesis of gastric mucosal injury induced by PAF.

Animals↗
PubMed1989

[Analysis of trophoblast subpopulations on touch smears of chorionic villi during normal pregnancy].

Trophoblasts of normal human pregnancy are classified into syncytiotrophoblasts (STs), cytotrophoblasts (CTs) and intermediate trophoblasts (ITs) which exist in cell columns and so forth. We analyzed the trophoblast subpopulations which appear on touch smears of chorionic villi morphologically and immunohistochemically, using the uterine contents of 37 cases of induced abortion. Troma 1, a rat monoclonal antibody, was utilized as a trophoblast marker and a mouse monoclonal antibody to HLA-A,B,C was employed to discriminate ITs from CTs. The results were as follows: 1. Two sorts of cells were positive for Troma 1 and therefore were considered to be trophoblastic: Multinuclear cells of various sizes and relatively large mononuclear cells. 2. Multinuclear trophoblasts were thought to be STs because of their characteristic cytomorphology and negative reaction for HLA-A,B,C. 3. The lower the gestational age was, the more ITs were observed. 4. The cellular and nuclear size of ITs varied and their chromatin was coarsely granular with aggregates. In addition one or more marked nucleoli were noted. Consequently it would be important to take care not to misdiagnose ITs as trophoblasts of a malignant nature.

Antibodies, Monoclonal↗
PubMed1989

[Malignant thymoma detected by thallium-201 myocardial scintigraphy].

We present two cases of malignant thymoma which showed a remarkable accumulation of thallium-201 chloride on myocardial scintigraphy. A 69 year-old man underwent stress 201Tl scintigraphy to evaluate myocardial ischemia and abnormal accumulation of thallium activity was observed in the anterior mediastinum by chance. It was more clearly visualized on delayed image. Moreover, abnormal uptake of 67Ga citrate was also observed in the same region. In another 68 year-old woman, there was high uptake on 201Tl scintigraphy, but no abnormal uptake using 67Ga. The diagnosis of malignant thymoma was confirmed by operation in each patient. These two cases had no abnormality in the mediastinum on the chest X-ray film and one of them had no uptake of 67Ga, 201Tl scintigraphy was more useful to detect malignant thymoma.

Aged↗
PubMed1989

Further studies on the cyto-, fibro- and dendro-architectonic structures of chicken diencephalon and mesencephalon.

Cyto-, fibro- and dendro-architectonic analyses of the diencephalic and mesencephalic area in chickens were carried out by means of the Nissl staining, silver impregnation and Golgi-Cox techniques. Within this area, a number of nuclei and fiber bundles were described and summarized in the form of cyto- and fibro-architectonic atlases of the frontal planes at the same level. Furthermore, with special reference to the optic tectum, detailed cyto- and dendro-architectonic observations were performed. Cytoarchitectonically, this area was composed of 15 alternately arranged layers from the surface inward, 3 of which were fiber bundle zones demonstrated more clearly in silver-impregnated preparations. On the other hand, in dendro-architectonic preparations, only 4 zones were identified; external horizontal, external vertical, internal horizontal and internal vertical cell layers. Among them, small fusiform and large pyramidal cell types in the external vertical cell layer as well as large stellate cells in the internal horizontal zone were histologically characterized. Further means of performing more detailed architectonic analysis of all nuclei and fiber bundles in the diencephalic and mesencephalic area were discussed and this may be useful for the physiological and anatomical studies.

Animals↗
PubMed1989

Multiple rheumatoid bursal cysts.

We have encountered a patient with rheumatoid arthritis (RA) who developed multiple subcutaneous swellings containing sterile milky fluid. The resected material showed chronic granulomatous changes compatible with rheumatoid inflammation. We suggest that multiple chronic rheumatoid inflammation may occur in the bursae as well as joint synovium as one of the extraarticular manifestations of RA.

Arthritis, Rheumatoid↗
PubMed1989

[Evaluation of disease activity by hand X-ray findings in rheumatoid arthritis].

It would appear to us that the patients with rheumatoid arthritis (RA), in whom articular bone lesions were confined to the wrist and/or carpal joints in X-ray films, may follow a milder disease activity than do the patients with the hand and finger joint lesions. To clarify it, the present study was performed retrospectively. RA patients showing stage II or more lesions in the wrists and/or carpal joints but no lesions over stage II in any hand and finger joint (MCP, IP and PIP) radiologically after 5 years or more duration were regarded as the carpal type (C type). The clinical and laboratory data were compared between 44 patients of the C type RA and 44 patients of other type RA, matched in the sex, age and disease duration. Significant differences were observed in the following parameters between the 2 groups; the functional class, Lansbury's activity index, number of the affected joints, ESR, CRP and hemoglobin values, and ADL scores. That is, Hb values and ADL scores were higher, but the others were lower, in the C type RA group than in other type RA group. The positive percentage and titer of rheumatoid factor were not significantly different between the 2 groups. It was concluded that C type RA patients are milder in the activity and fewer in the number of affected joints than other type RA patients. Furthermore it was suggested that C type RA patients may have milder clinical course and better prognosis than other type RA patients.

Adult↗
PubMed1989

[Antibodies to cytoskeletal systems in patients with adult T-cell leukemia and infectious mononucleosis].

Serum antibodies to cytoskeletal systems were measured by indirect immunofluorescence using human skin fibroblasts and HEp2 cells as substrate. Healthy adults had IgM antibodies to vimentin and cytokeratin at 60 times serum dilution. IgG concentration did not have a correlation with IgG anti-cytoskeletal system antibodies and IgM concentration correlated with anti-vimentin and anti-cytokeratin antibodies. In patients with adult T-cell leukemia (ATL), IgG antibody titer against actin and vimentin was increased in spite of a decreased IgG concentration. IgM antibodies to vimentin was decreased in its titer together with a decreased IgM concentration. Antibody titer to HTLV-1, leukemic cell counts in peripheral blood and disease type, acute or chronic, did not have correlations with anti-cytoskeletal system antibodies. A third of the patients with ATL showed negative anti-EBNA antibody, suggesting that the functional impairment in EBV-specific killer cells was present. In contrast, the patients with infectious mononucleosis showed increased serum IgM concentration and IgM anti-vimentin antibody titer. It was suggested that the autoantibodies to cytoskeletal systems associated with viral infection were mainly composed of IgG in ATL and of IgM in infectious mononucleosis.

Adult↗
PubMed1989

[Study on the change in serum enzyme activity during acute aortic dissection].

Cases of acute aortic dissection presenting to the First Department of Surgery at Toyama Medical and Pharmaceutical University Hospital were divided into 2 groups according to the presence or absence of complications such as electrocardiographic abnormalities, hepatic or renal dysfunction, intestinal necrosis, and leg ischemia. After hospitalization such complications were completely absent in the "complication-free group", but were present in the "complication group". Fluctuations in serum enzyme activity (CK, LDH, GOT, GPT) were measured, and the 2 groups compared. In the complication-free group, serum CK activity was significantly elevated at 273.3 +/- 154.5 IU/l, reaching a peak on the first day, after which it decreased to normal by the fourth day. In the complication group, fluctuations in the serum enzyme activity levels corresponded to the type of complication, with the fluctuations paralleling changes in the clinical course. Also, CK activity was measured in aortic wall specimens obtained at autopsy, and the CK activity of 585.0 +/- 35.3 IU/g protein demonstrated. From the above it was thought the transient elevation of serum CK activity found in uncomplicated aortic dissection is due to the CK released from the dissected aortic wall into blood.

Acute Disease↗
PubMed1988

Influence of exercise on plasma atrial natriuretic factor levels in patients with myocardial infarction.

The influence of dynamic exercise on plasma atrial natriuretic factor (ANF) levels was studied in a group of 10 patients with myocardial infarction (MI) and five patients with atypical chest pain (control group). Exercise protocol consisted of three fixed workloads (25, 50, and 75 watts) every 4 minutes with the use of a supine bicycle ergometer. Plasma ANF levels and hemodynamic indices were measured before, during, and 10 minutes after exercise. In the MI group, plasma ANF levels significantly increased at the 75-watt workload and significantly decreased at 10 minutes after exercise, whereas in the control group, the increase in plasma ANP levels after a 75-watt workload, compared with those at rest, was not significant. Significant correlations of pulmonary artery wedge pressure, right atrial pressure, mean arterial pressure, and heart rate to plasma ANF levels were observed at four points obtained before and during each stage of exercise in the MI group. Furthermore, a significant correlation between maximal creatine kinase levels and plasma ANF levels at a 75-watt workload and a significant inverse correlation between left ventricular ejection fraction and plasma ANF levels at a 75-watt workload were observed. These results suggest that the increase in the circulating ANF level during exercise in MI is associated with elevated atrial pressure resulting from left ventricular dysfunction and that measurement of ANF during exercise may be an indication of the severity of MI and associated left ventricular dysfunction.

Adult↗
PubMed1988

Classification of the neurons in fowl hypothalamic nuclei based on their dendritic patterns.

1. Dendroarchitectonic analysis of the hypothalamic nuclei in the fowl was investigated by the Golgi-Cox, Nissl and silver impregnation techniques. 2. All hypothalamic nuclei appeared to consist of leptodendritic neurons constituting a variety within the isodendritic family. They showed triangular, spindle and round shapes and had a few long, relatively straight, fine dendrites bearing very fine dendritic spines. 3. Neurons in the nucleus preopticus medialis et lateralis showed a bipolar spindle-shape and had stout, relatively long primary dendrites. 4. Those in the nucleus hypothalamicus rostralis medialis et lateralis were characterised by bipolar, spindle-shaped and multipolar leptodendritic neurons and by short fine primary dendrites bifurcating to fine longer secondary segments. 5. Neurons in the nucleus hypothalamicus caudalis medialis et lateralis and nucleus hypothalamicus inferior were of the multipolar leptodendritic type and had thick, long, unbranching dendrites emerging directly from the cell body. 6. The fowl hypothalamus is dendroarchitectonically divided into preoptic, rostral and caudal hypothalamic regions; the borderlines separating them are the commissura rostralis and the region between the nucleus hypothalamicus rostralis medialis and nucleus hypothalamicus caudalis medialis, respectively.

Animals↗
PubMed1988

Hereditary hemorrhagic telangiectasia with growing pulmonary arteriovenous fistulas followed for 24 years.

A 47-year-old man was admitted for follow-up of an abnormal chest x-ray. He had a history of epistaxis and a brain abscess and a family history of pulmonary arteriovenous fistulas. Physical examination showed clubbed fingers and telangiectasia of the tongue. Laboratory data revealed evidence of polycythemia and hypoxia. Contrast echocardiography and pulmonary perfusion scintigraphy were suggestive of a right-to-left shunt. From the oxygen tension and content of blood taken at cardiac catheterization, the shunt ratio was calculated to be 57.8%. Multiple bilateral pulmonary arteriovenous fistulas were confirmed by angiography, and the patient was diagnosed as having hereditary hemorrhagic telangiectasia. A review of x-ray films taken over a 24-year period demonstrated that the fistulas in both lungs had been increasing gradually in size at different rates. A right lower lobectomy relieved the hypoxia, but the patient died unexpectedly on the twelfth postoperative day. There was no evidence of fistula rupture on chest film, but no autopsy was performed.

Arteriovenous Fistula↗
PubMed1988

Relationship between cardiac function and the sympathetic nervous system during exercise in patients with essential hypertension.

The relationship between echographical cardiac function and sympathetic nerve activity during dynamic exercise was examined in patients with essential hypertension. Nine normotensives (Group N), 11 hypertensive patients without cardiac hypertrophy (Group NH) and 13 hypertensive patients with cardiac hypertrophy (Group HH) were studied during multistage exercise using a supine bicycle ergometer. The shortening fraction (SF) and the peak negative dD/dt in Group HH, being within the normal range, tended to be smaller than those in Group N at the 75-watt load. The mean value of the peak positive dD/dt (+dD/dt) in Group HH was significantly smaller than that in Group N at rest and during the 75-watt load. The percent increase of plasma norepinephrine (NE) levels (% delta NE) at the 75-watt load was significantly greater in Group HH than in Group N. Plasma NE, in some patients with cardiac hypertrophy and compromised cardiac function, markedly increased (% delta NE greater than or equal to 186) during exercise. % delta NE was directly related to the left ventricular mass index among all of the groups, but it was inversely related to the SF, -dD/dt, and to +dD/dt at the 75-watt load. We conclude that the augmented sympathetic nerve activity may contribute to preserving left ventricular systolic function during exercise within the normal range in hypertensive patients with cardiac hypertrophy.

Adult↗
PubMed1988

Physiological significance of atrial natriuretic peptides in essential hypertension.

To investigate the significance of atrial natriuretic peptides (ANP) in essential hypertension, plasma ANP concentrations in 43 essential hypertensives, 16 borderline hypertensives and 17 normotensive controls were measured. Furthermore, effects of high-sodium and low-sodium intakes on plasma ANP concentration were examined in "salt-sensitive" [SS] and "nonsalt-sensitive" [NSS] patients with essential hypertension. Plasma ANP concentration was significantly higher in hypertensives than in borderline hypertensives and in normotensive controls. No significant difference in plasma ANP concentration was observed between borderline hypertensives and normotensive controls. Plasma ANP concentration increased with the high-sodium diet in both the SS and NSS patients, but the mean increment was significantly greater in the SS than the NSS patients. Urinary excretion of sodium was lower in the SS patients taking the high-sodium diet than the corresponding value in the NSS patients. These findings suggest that an increased level of circulating ANP in hypertensive patients represents a compensatory mechanism to offset further elevation of blood pressure and sodium retention.

Atrial Natriuretic Factor↗