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Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 1,225 records · Page 68Linked to original sources
PubMed1983

[Immunohistochemical studies of hemangioblastoma with glial fibrillary acidic protein].

Sixteen cases of CNS hemangioblastoma were examined for glial fibrillary acidic protein (GFAP) using the immunoperoxidase method. In 13 cases GFAP-positive cells were found in the tumor. In all positive cases reactive gliosis in the form of trapped reactive astrocytes and their cytoplasmic processes penetrated the margin of the tumor. In 4 of the positive cases GFAP-positive cells were present deep in the tumor. Aggregates of GFAP-positive cells and fibrils were especially prominent in a recurrent case. Because hemangioblastomas grow without capsule into the cerebellar tissue, it is considered that reactive astrocytes and their fibrils are easily included and trapped within the tumor. In two cases GFAP-positive plump stromal cells, which were definitely different from the reactive astrocytes, were seen. They were neighbored with the dense gliotic foci or on and around the microcyst wall. This may be interpreted as that the stromal cells have a capacity to incorporate the extracellular GFAP derived from the intratumoral gliotic foci or cysts.

Adolescent↗
PubMed1983

Enhancement of human T lymphocyte colony formation by 12-O-tetradecanoylphorbol-13-acetate (TPA).

The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on human T lymphocyte lymphocyte colony formation in vitro were investigated. The number of T lymphocyte colonies was increased 4-5 times over that of controls by the addition of TPA (10(-7) - 10(-9) M) to phytohemagglutinin (PHA)-containing cultures. Few colonies were observed when stimulated with TPA in the absence of PHA. In the cultures containing a sufficient amount of exogenous T cell growth factor (TCGF), the enhancement of T lymphocyte colony formation by TPA was not observed. TPA enhanced TCGF production by peripheral lymphocytes stimulated with PHA. The optimal concentrations of TPA for T lymphocyte colony formation were similar to those for TCGF production. These findings suggest that TPA enhanced T lymphocyte colony formation by stimulating endogenous TCGF production. Interestingly, T lymphocyte colony formation was not inhibited even at high concentrations of TPA that usually inhibit myeloid and erythroid colony formation. This difference may be due to different sensitivities to TPA between T lymphocyte colony-forming cells and myeloid and erythroid colony-forming cells.

Cell Division↗
PubMed1983

[Echocardiography of ischemic heart disease simulating dilated cardiomyopathy, with special reference to abnormal wall movement on the short-axis].

The purpose of this study was to determine whether two-dimensional echocardiography (2DE) can differentiate ischemic myocardial disease (IMD) from dilated cardiomyopathy (DCM). The subjects consisted of six cases of IMD which showed left ventricular dilatation (LVDd greater than or equal to 60 mm) and diffuse abnormality of wall motion, but did not show obvious localized myocardial infarction or left ventricular aneurysm on 2DE, and 16 cases of DCM. Two cases of IMD had previous myocardial infarction, and five cases of DCM had cardiomegaly following myocarditis. A short-axis image of the left ventricle was recorded at the chordal and the papillary muscle levels. Each image was divided into 4 segments, which were comprised of the septum, anterior wall, lateral (posterolateral) wall, and posterior (posteromedial) wall. Regional wall motion abnormality with reference to systolic thickening was analyzed qualitatively in each segment. The results were as follows: In ECG findings in IMD group, only one case showed abnormal Q waves and five cases showed left ventricular hypertrophy (LVH) similar to intraventricular conduction defect. On the other hand, in DCM group seven cases showed abnormal Q waves and five cases showed LVH. Two cases of IMD had two-vessel disease and four three-vessel disease, respectively. Left ventricular ejection fraction by cine-angiography ranged from 0.10 to 0.39 (mean 0.24) in IMD group and from 0.22 to 0.42 (mean 0.36) in DCM group. Mean LVDd showed no significant difference between these two groups. Five cases of DCM showed marked left ventricular dilatation (LVDd greater than or equal to 75 mm), but there were no such cases in IMD group. B-B' step was recognized in only one case of IMD, though it was present in eight cases in DCM. In regional wall motion, incidence of asynergy such as akinesis or dyskinesis was higher in IMD group than in DCM group. Left ventricular asynergy was more serious in the posteromedial wall than the posterolateral wall at the same image in five cases of IMD. However, in 12 cases of DCM, the degree of asynergy was equal at the both walls. In conclusion, it is recommended to examine echocardiographically the extent of severe asynergy in the posteromedial and posterolateral walls in order to differentiate IMD from DCM.

Adolescent↗
PubMed1983

[Ultrastructure of human oligodendroglioma].

Ten cases of human oligodendroglioma were examined with electron microscope. The materials were specimens derived through surgical operations. Results were as follow. The shape of tumor cells are various, round, oval, polygonal and irregular. The majority of tumor cells have round or ovoid nuclei, some have irregular nuclei or nuclear indentation. Chromatin distributions tend to clump. In the cytoplasm, there are commonly ribosomes, rough surfaced endoplasmic reticulums, mitochondria, microtubules and lysosome. Glial filament is rare or almost absent. Crystalline structures are seen in 3 cases. Cellular junctions, though immature, are seen in 4 cases. Perinuclear halo in the light microscopy was explained to be a fixation artifact in 10% formol. The samples, which were fixed in 2.5% cold glutaraldehyde and post-fixed in 1% osmium tetraoxide, did not show perinclear halo under the light and electron microscope. The specimen, which were fixed in 10% formol, were examined with electron microscope. Plasma membrane of the tumor cell was partly destroyed, intracytoplasmic organelles and matrix were also broken, and the cytoplasm was empty. It is confirmed in this study that empty cytoplasm represents the peculiar perinuclear halo in the light microscopy.

Brain Neoplasms↗
PubMed1983

Hidroacanthoma simplex with invasive growth.

Hidroacanthoma simplex is a benign tumor of the skin, macroscopically resembling seborrheic keratosis or Bowen's disease, and histologically revealing intraepidermal focal growth of epithelial cells. A case of hidroacanthoma simplex with a malignant portion is presented in this report. The present case revealed mostly histologic characteristics of hidroacanthoma simplex, but the central portion of the tumor showed downward invasive growth with increased cellular atypia. The malignant change of hidroacanthoma simplex is discussed in relation to eccrine porocarcinoma (malignant eccrine poroma).

Humans↗