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Biomedical subjects

T Iwase

Publications and source records attributed to T Iwase.

At least 199 records · Page 11Linked to original sources
PubMed1984

Immunohistochemical and ultrastructural analysis of the proliferating cells in histiocytosis X.

The cellular nature of the proliferating histiocytes in 6 cases of histiocytosis X was studied immunohistochemically and ultrastructurally. Immunohistochemically, S-100 protein was detected both in the cytoplasm and the nuclei of histiocytosis X cells as well as Langerhans cells in normal oral epithelium. These cells were always negative for lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin and immunoglobulins. S-100 protein was not detected in lysozyme-positive histiocytes and multinucleated giant cells often showed the signs of phagocytosis. Thus, S-100 protein appears to be a useful immunohistochemical marker for histiocytosis X cells. Ultrastructurally, Birbeck granules noticed in histiocytosis X cells were never seen in the phagocytic histiocytes with numerous lysosomes and phagosomes. These results emphasized the heterogeneous nature of the proliferating histiocytes involved in the lesions. Since histiocytosis X cells share characteristics, not only ultrastructurally but also immunohistochemically, with Langerhans cells, the hypothesis that histiocytosis X may be fundamentally an abnormal proliferation of Langerhans cells has been further supported.

Cell Division↗
PubMed1984

Evaluation of effects of aging, training and myocardial ischemia on cardiac reserve by exercise echocardiography.

Exercise tolerance and heart response were examined by cross-sectional echocardiography before and during exercise tests to assess the effects of aging, training and myocardial ischemia on the cardiac reserve of 40 healthy men, 20 athletes and 25 patients with angina on effort. The cardiac response to exercise can be divided into 4 types according to parameters derived from a short axis section echocardiogram. Type A: The left ventricular end-diastolic volume (LVEDV) increased slightly in the early stage of exercise, and thereafter, the cardiac response was maintained by a gradual increase of myocardial contractility and heart rate. Type B: Initial response to exercise was similar to Type A, but cardiac output was maintained only by an increase of heart rate under additional exercise load. Type C: LVEDV, LVESV (left ventricular end-systolic volume) and contractility remained virtually unchanged throughout the exercise. Type D: The contractility decreased from the early stage of the exercise, and LVEDV and LVESV increased. Most young subjects and all athletes showed Type A response, while in the aged healthy subjects the Type B response was more frequent. Anginal cases tolerating 125-watt load responded as Type B or C, and those tolerating only 75 watts showed Type C or D. All patients in Type D had multi-vessel disease.

Adult↗
PubMed1982

[Evaluation of cardiac reserve in patients with angina pectoris by dynamic exercise echocardiography].

To evaluate cardiac reserve in patients with angina pectoris, 10 healthy control subjects and 15 patients with angina pectoris were examined by exercise echocardiography. Exercise on the bicycle ergometer in supine position was imposed at 25 watts per min initially and the exercise was increased by 25 watts every 3 min until attainment of either maximal predicted heart rate or ST segment depression in the electrocardiogram (ECG) or appearance of severe chest pain. Blood pressure, two-dimensional echocardiogram at the level of the papillary muscle in the short-axis view (Fig. 1) and 12 leads ECG were recorded at the end of each exercise level. Cardiac response to the exercise was evaluated by blood pressure, areas of left ventricular cavity at the end diastole and end systole, percent change of the area, ejection fraction and mVCF, as shown in Figs. 2, 3 and 4. From these parameters, the behavior of cardiac response to exercise was divided into four types (cf. Fig. 5). Type A: left ventricular volume was increased slightly at the initial stage of exercise, and thereafter, the cardiac response was maintained by a gradual increase of myocardial contractility. Type B: initial response to exercise was similar to type A, but cardiac output was maintained only with an increase of heart rate in further exercise load. Type C: left ventricular contractility and increased left ventricular volume were observed from 25 watts load of exercise. Most of the control subjects responded as type A. Patients with angina who underwent 125 watts exercise showed type B response, while those who tolerated only 75 watts exercise revealed type C or type D (Table 1). The latter indicates decreased cardiac reserve to exercise. From the results of 10 patients who showed ST depression during exercise, deterioration of left ventricular contractile function appeared before ST segment depression, indicating that a change in mechanical pump function preceded electrical function of the myocardium (Fig. 6). It may be concluded that serial changes of cardiac parameters obtained from dynamic exercise echocardiography with an area-based method is useful to identify decreased cardiac reserve in patients with angina pectoris.

Angina Pectoris↗