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Biomedical subjects

I Watanabe

Publications and source records attributed to I Watanabe.

At least 523 records · Page 29Linked to original sources
PubMed1981

Ultrastructure and pathogenesis of intracranial arachnoid cysts.

A detailed light, transmission, and scanning electron microscopic study of the arachnoid cyst wall was made in four cases and compared with that of the normal arachnoid mater in the human. Two hundred and eight reported cases of arachnoid cysts were analyzed to evaluate the anatomical distribution of these lesions and to get r an insight into their pathogenesis. The structural features of the arachnoid cyst wall that distinguish it from the normal arachnoid membrane are as follows: (1) splitting of the arachnoid membrane at the margin of the cyst, (2) a very thick layer of collagen in the cyst wall, (3) the absence of traversing trabecular processes within the cyst, and (4) the presence of hyperplastic arachnoid cells in the cyst wall, which presumably participate in collagen synthesis. The distribution of arachnoid cysts in two hundred and eight reported cases was as follows: Sylvian fissure, 49%; cerebellopontine angle, 11%; supracollicular area, 10%; the vermis, 9%; sellar and suprasellar area, 9%; interhemispheric fissure, 5%; cerebral convexity, 4%; and the clival and interpeduncular area, 3%. At each site, except possibly on the cerebral convexity, the cyst was associated with a normal subarachnoid cistern. This striking and nearly invariable association of arachnoid cysts with normal subarachnoid cisterns prompts the authors to hypothesize that arachnoid cysts represent a congenital anomaly of the developing subarachnoid cisterns in early intrauterine life. It is postulated that, during the process of the complex folding of the primitive neural tube and the formation of normal subarachnoid cisterns, an anomalous splitting of the arachnoid membrane occurs.

Arachnoid↗
PubMed1981

[A case of intracranial mesenchymal chondrosarcoma--changes observed by computed tomography before and after radiotherapy (author's transl)].

Intracranial mesenchymal chondrosarcoma is very rare, only 14 cases being reported in Europe and in the United States of America. Recently we experienced a case in which the follow-up indicating computed tomograms (CT) demonstrated interesting data on the radiosensitivity of this tumor. The patient, a 14-year-old female was admitted to out hospital with the complaint of left hemiplegia which had gradually progressed. CT revealed an area spreading upward from the right median base of the skull and consisted of two components showing (A) a density as high as that of calcium and (B) a density higher than that of surrounding brain tissue, but much lower than that of calcium. Temporoparietal craniotomy was performed to react approximately one-half of the tumor. Histological finding revealed mesenchymal chondrosarcoma. The component-A was though to be a cartilaginous tissue, and-B to be an undifferentiated mesenchymal tissue. Postoperative irradiation of 7,000 rad was initiated. The effect of radiotherapy as seen on computed tomograms is as follows, (1) decrease in the volume of the tumor by 26%, (2) decrease in density and enhancement of the area which is considered to be the undifferentiated mesenchymal cells, (3) mild reduction of the area which is considered to be the cartilaginous tissue, and (4) a very high density of the entire tumor similar in degree to that of the bone one year later. These results suggested that radiotherapy is effective for this tumor.

Adolescent↗
PubMed1981

[The effect of the spatial distance upon visual stream segregation (author's transl)].

When 4 lights arranged in a line in the order of A, B, C, D, are flashed successively in the order of A, C, B, D at a moderately high speed, two beta-movements can be seen, one across A and B, and the other C and D. Bregman and Achim (1973) named this phenomenon VISS (visual stream segregation). Four experiments were performed under various conditions for the spatial distance between the lights. Subjects were required to find the upper limits of ISI for producing VISS. It was found that VISS is affected mainly by the distance between the two beta-movements, namely, that between B and C.

Female↗
PubMed1980

Secondary carcinoma of the thyroid gland.

When the cervical tumor mimics thyroid carcinoma, some cases are shown to be the primary carcinoma of other site. Four cases of secondary thyroid carcinoma, of which primary sites are adjacent organ, are studied. The characteristics of histology are squamous cell carcinoma. Squamous cell carcinoma of which primary organ seems to be thyroid often discloses metastatic neoplasm originated from the adjacent organs. Since chronically inflammatory lesion is recognized concurrently, abnormal thyroid is suggested to be congenial soil for malignant growth. Our experience indicates that the secondary carcinoma due to direct extension should be considered on diagnosing squamous cell carcinoma of the thyroid.

Carcinoma, Squamous Cell↗
PubMed1980

Sclerosing vascular variant of plasma cell granuloma.

A single mass in the right lung was found in a 33 year old asymptomatic male by routine chest x-ray examination. In the surgically removed right middle lobe was a well circumscribed but nonencapsulated round tumor (diameter, about 4 cm.) compressing and gradually becoming incorporated into the adjacent pulmonary parenchyma. Histologically the bulk of the tumor consisted of numerous hyalinized blood vessels in a loose mesenchymal background, the latter containing spindle shaped connective tissue cells and an acid mucopolysaccharide stroma. At the margins in the fibrous septa, which divided the tumor into nodules, there was intense lymphoplasmacytic infiltrates forming lymphoid follicles. No epithelial elements were observed around the hyalinized blood vessels. Electron microscopic findings suggest mesenchymal cells, giving rise to endothelial cells of numerous blood vessels and spindle cell connective tissue cells associated with unique lymphoplasmacytic aggregates. The unusual tumor best fits the characteristics of the sclerosing plasma cell granuloma, composed predominantly of sclerosing vascular vessels.

Adult↗
PubMed1980

Pancreatic cancer with metastasis to the larynx.

A laryngeal metastasis from pleomorphic carcinoma of the pancreas is described. The patient was a 70-year-old male. The tumour was located on the right margin of the epiglottis. Bilateral neck lymph node metastases were also found. The patient underwent supraglottic laryngectomy, right radical neck dissection and left suprahyoid neck dissection. Following surgery, the patient's general condition deteriorated day by day, and one month after the surgery he died. The autopsy findings demonstrated a big mass of cancer in the pancreatic tail, multiple lymphatic metastases, carcinomatous peritonitis, and possibly a lymphatic spread of the pancreatic cancer to the larynx.

Aged↗
PubMed1980

Chemical injury of the spinal cord of the rabbit after intracisternal injection of gentamicin: an ultrastructural study.

We previously reported that rabbits with quadriplegia, after a single intracisternal injection of gentamicin sulfate, have multiple minute lesions in the white matter of the upper cervical spinal cord and the lower medulla oblongata, most marked at the C2 segment, when light microscopy is used to study the histopathologic changes. Using electron microscopy in the present investigations, we have found that 9 hours after injection of gentamicin sulfate there was marked edema of fibrous astrocytes in the soma and processes of glia limitans. Ribosomes were disarranged. Mitochondria were swollen, the matrix density was increased and contained paracrystalline lattice structure, and the cristae were reduced in number. Oligodendrocytes displayed hypertrophy, with proliferation of smooth ER, ribosomes, microtubules, Golgi complexes, and lysosomes. A few axons were subsegmentally swollen due to axoplasmic edema. At 24 hours, the lesions became obvious by light microscopy. Astrocytes were more edematous and oligodendrocytes remained hypertrophic. Myelin sheaths were tumefied by dissociation of myelin lamellae. Axons were edematously swollen. Lysed axons were surrounded by lysed myelin sheaths. At 48 hours, numerous neuroaxonal end bulbs were formed at the lysed end. Wallerian degeneration was also evident. The data suggest that oligodendroglia actively react to detoxify gentamicin, astroglia become severely edematous but survive, and axons and myelin sheaths are lysed in reaction to the toxicity of gentamicin. The unique distribution of gentamicin lesions in the deeper white matter, with sparing of the overlying marginal myelinated fibers, seems to depend primarily upon the distribution of edematous astrocytes, which are most sensitive to this noxious chemical. Since gentamicin is apparently detoxified by oligodendroglia, the regenerative process of axons starts after a short period of axonal lysis.

Animals↗