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Biomedical subjects

N Arita

Publications and source records attributed to N Arita.

At least 145 records · Page 8Linked to original sources

Hypothalamic hamartoma: report of two cases.

Two histologically confirmed hypothalamic hamartomas, one in a 7-year-old boy and another in a 10-year-old boy, are reported. One patient had precocious puberty, epileptic laughter, and abnormal behavior; the other had cerebral seizures. Partial removal of the tumors had no effect on precocious puberty; however, behavior improved in the first patient, and seizure control improved in the second patient.

Child↗

Immunohistochemical study of metastatic brain tumors with astroprotein (GFAP), a glia-specific protein. Tissue architecture and the origin of blood vessels.

Tissues from 12 metastatic tumors of the brain were studied immunohistochemically with an antiserum to a glia-specific protein, astroprotein (glial fibrillary acidic protein, GFAP). Emphasis was laid on demonstrating the tissue architecture of metastatic lesions incorporating brain-derived components (astrocytes and glial fibers). Of 12 samples, 11 manifested a number of irregular indentations at the tumor surface. These indentations, which contained astrocytic elements, extended into the tumor tissue in a tapering fashion. In seven cases, the deeper stromal portions of the tumor also contained astroprotein (GFAP)-positive elements. The presence of this glia-specific protein suggests that the stroma of the tumor tissue may in part be derived from preexisting brain tissue. This peculiar tissue architecture of the tumor supports the hypothesis that some of the blood vessels that are located in the stroma of the tumor tissue are also derived from the brain. These observations may be important in understanding the partial preservation of the blood-brain barrier in metastatic brain tumors and the mode of growth of the metastatic lesion, and in selecting the type of chemotherapy that will be most effective in controlling this central nervous system complication of systemic malignancies.

Astrocytes↗

Chemotherapy of malignant gliomas.

Chemotherapy of malignant glioma has been discussed in relation to recent advances in experimental and clinical studies. It is now obvious that chemotherapy is of increasing importance in the multidisciplinary treatment of malignant gliomas. Survival time of patients was prolonged by intensive and prolonged chemotherapy and by second treatment upon tumour recurrence. Further progress of chemotherapy will be gained by the progressive accumulation of all experiences, however small, in all the varied routes of approach.

Animals↗

Prostatic leiomyosarcoma revealing cytoplasmic virus-like particles and intranuclear paracrystalline structures.

This report concerns an ultramicroscopic study of an autopsy case of primary leiomyosarcoma of the prostate in a patient who died of widespread blood-borne metastases after a rapid clinical course. Ultrastructural observation of tumor cells demonstrated some characteristics of leiomyosarcoma and furthermore revealed frequent intranuclear structures in paracrystalline array together with aggregates of interchromatin granules and cytoplasmic virus-like particles.

Adult↗

[Clinical studies of meningeal gliomatosis].

Ten (23%) patients out of 43 with malignant glioma developed meningeal gliomatosis during the follow up period of at least one year. The duration between the first surgery and diagnosis of meningeal gliomatosis ranged from one to 78 weeks (median 45 weeks). In younger age group less than 20 years old, 5 (56%) out of 9 patients had meningeal gliomatosis, and on the contrary the incidence was lower in older age group above 20 years old (5 of 34, 15%). Seven (22%) out of 32 male and 3 (27%) out of 11 female patients developed meningeal gliomatosis. The primary tumor location were frontal lobe in 4 cases (including one bifrontal tumor), temporal in 2, parieto-occipital in 1, thalamus in 1, midbrain in 1, and cerebellar hemisphere in 1, respectively. Histologically, 7 tumors were anaplastic astrocytoma, and 3 were glioblastoma. The characteristic neurological findings observed during the course of meningeal gliomatosis were abnormal mental status (80%), cranial nerve palsies (50%), paraplegia (60%), stiff neck (80%), seizure (50%), and respiratory disturbance (80%), CSF cytology was positive in all 9 patients tested. CT scan demonstrated hydrocephalus (70%), and diffuse contrast enhancement of ventricular wall (60%) and basal cistern (10%). In 2 cases, block and irregular filling defect were seen by myelography. Six patients were treated by irradiation to the whole brain and/or spine, and 5, by intrathecal chemotherapy with methotrexate, cytosine arabinoside and bleomycin. However, all patients died of the tumor one to 46 weeks (median 18 weeks) after the diagnosis of meningeal gliomatosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Meningeal gliomatosis: development of experimental models].

Experimental models of meningeal gliomatosis (MG) have been produced by intracisternal inoculation of C6 glioma and 9L glioma cells into Wistar and Fisher 344 rats, respectively. The tumor growth was steady and fast in both MG models if 10(6) cells were implanted. Median survival time(MST) of rats inoculated with tumor cells was inversely related to the number of cells inoculated. The clinicopathological features observed in both MG models were similar to those seen in diffuse leptomeningeal involvement of gliomas in human beings. The models will be useful for investigating the pathophysiology of meningeal gliomatosis and the efficacy of chemotherapeutic agents.

Animals↗

Primary colonic plasmacytoma associated with acute myelogenous leukemia.

We present a case of primary colonic plasmacytoma associated with acute myelogenous leukemia in a 32-year-old man. The neoplastic plasma cells revealed monoclonal lambda-light chains in the cytoplasm using immunoperoxidase techniques. Histochemical and electron microscopic findings are described with a review of the literature.

Adult↗

Solitary plasmacytoma of the submandibular lymph node with stromal amyloid deposits.

This report concerns a case of solitary extramedullary plasmacytoma of the left submandibular lymph node in a 56-year-old man. The tumor showed monoclonal proliferation of abnormal plasma cells which revealed highly positive stainings of both methylgreen pyronin and kappa light chain using the immunoperoxidase technique in the cytoplasms, and further revealed massive amyloid deposits in the stroma, which suggested the possibility of sequential amyloid formation upon the secretion of paraprotein by tumor cells.

Amyloid↗

Effects of methylprednisolone on peritumoral brain edema. A quantitative autoradiographic study.

Peritumoral brain edema was produced by intracerebral transplantation of Walker 256 tumor in rats. Local cerebral blood flow (LCBF), local cerebral glucose utilization (LCGU), and capillary permeability were studied in untreated and methylprednisolone-treated rats by quantitative autoradiography. In the untreated group, LCBF and LCGU were widely depressed in the cortex and deep structures of the hemisphere ipsilateral to the tumor. In the methylprednisolone-treated animals, LCBF and LCGU were significantly better than in the untreated animals. Capillary permeability was highly increased in the viable part of the tumor in the untreated animals. In the methylprednisolone-treated group, capillary permeability of the tumor was significantly lower than that in the untreated group. These results may suggest that increase in capillary permeability of the tumor is the major source for edema fluid production, and that methylprednisolone improves brain edema by decreasing capillary permeability of the tumor. Decrease in edema fluid formation may result in restoration of blood flow and glucose metabolism in the adjacent brain tissue, and may improve clinical symptoms and signs.

Animals↗

[Germ cell tumor in the basal ganglia with elevated serum and CSF alpha-fetoprotein levels].

Intracranial germ cell tumors usually locate either in the pineal region or in the suprasellar region or both. Primary occurrence of germ cell tumor in the basal ganglia is rare. To our knowledge, only 17 cases have been reported in the literatures, and all the patients were Japanese. None of these patients presented elevated serum and CSF AFP levels in the literatures. We are reporting a patient with a germ cell tumor which developed in the left basal ganglia and showed high serum and CSF alpha-fetoprotein (AFP) levels. The patient was a 12-year-old boy who had been completely well until five months prior to the first admission when he developed weakness of right extremities. On admission he showed a right hemiparesis of mild degree and right hypesthesia. CT-scans demonstrated a homogeneous high density area over the caudate head and the putamen on the left side. The anterior limb of the left internal capsule and a part of the posterior limb were also involved. The lesion was moderately enhanced by the contrast medium. Stereotaxic biopsy of the lesion was uncontributory and he was discharged for follow up. Five months later, CT-scans demonstrated the enlargement of the high density area with perifocal edema. Then we performed a craniotomy, and the tumor which was soft and dark red in colour was biopsied at the wall of the anterior horn of the left lateral ventricle. Histopathology of the specimen showed germinoma of two-cell pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Basal Ganglia↗

[Effects of methylprednisolone on tumor-induced brain edema].

Local cerebral blood flow (LCBF), local cerebral glucose utilization (LCGU) and capillary permeability were studied in rats with tumor-induced brain edema. Moreover, effects of methylprednisolone on these physiological parameters were studied to analyse a possible role of steroid on treatment of peritumoral brain edema. A cubic millimeter pellet of Walker 256 tumor was transplanted to the left sensorimotor cortex of the rat brain. Animals were randomly divided into two groups. One group was treated with methylprednisolone (15 mg/kg/day) for 5 days starting at 5 days after tumor inoculation, and the other group received no treatment. These rats were used for autoradiographic study at 10 days after tumor inoculation. Local CBF, LCGU and capillary permeability were measured with 14C-iodoantipyrine, 14C-deoxyglucose and 14C-alphaaminoisobutyric acid, respectively. In the untreated group, LCBF and LCGU were widely depressed in the cortex and deep structures of the hemisphere ipsilateral to the tumor. Of the methylprednisolone treated animals LCBF and LCGU were significantly better than that of untreated animals. Capillary permeability of the untreated animals were highly increased in the viable part of the tumor. Some increase was also noted in the peripheral edge of the tumor and adjacent brain. In the methylprednisolone treated groups, capillary permeability was significantly lower than that in untreated group. The data suggest that methylprednisolone decreases capillary permeability in the viable part of the tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗