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Biomedical subjects

H Mogami

Publications and source records attributed to H Mogami.

At least 217 records · Page 12Linked to original sources

[Immunohistochemical study of ischemic neuronal damage with antiserum to tubulin, a microtubular protein].

The limitation of conventional histological methods to demonstrate ischemic change of neurons in early phase has been a major drawback in histopathological and pathophysiological studies of cerebral ischemia. Cellular metabolism is disturbed immediately after cessation of the regional circulation and rapid alterations in macromolecular and ultrastructural integrity in neurons may take place before any evidence of histopathological changes could be detectable. To demonstrate ischemic change of neurons more sensitively on a histological level, we applied immunohistochemical method using antiserum to tubulin, a protein of microtubules. As this organelle has been implicated in several important cellular functions such as control of cell shape, intracytoplasmic transport of materials or synaptic transduction, immunohistochemical alterations in microtubules may indicate structural as well as functional damage of neurons. In order to study the ischemic change in neurons, the posterior communicating artery of a gerbil brain was occluded by the method previously reported by us, and the hippocampus, which is one of the most vulnerable structures of the brain to ischemia, was observed. Five or 30 minutes after occlusion, animals were sacrificed by decapitation. Brains were removed, cut coronary vessels and fixed in ethanol-acetic acid (95:5). Tubulin used for this study was extracted from normal gerbil brains and specific antiserum was raised in goats Peroxidase-antiperoxidase method was performed on paraffin sections. Immunohistochemical distribution of tubulin in a normal gerbil brain demonstrated by the present method was in good accordance with the reported electronmicroscopical distribution of microtubules.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Sellar fibrosarcoma following radiotherapy for prolactinoma].

A 51-year-old house woman visited the Department of Neurosurgery, Osaka University Hospital for examination of the head injury on Oct. 7, 1975. Neurological examination was normal. Endocrinological examination showed galactorrhea. The patient had a past history of premature menopause. Plain skull films revealed enlargement of sella turcica and CT scan showed sellar tumor with suprasellar expansion which was enhanced by contrast medium. The serum prolactin (PRL) level was 3,290 ng/ml. Diagnosis of PRL secreting pituitary adenoma (prolactinoma) was made. Though surgical removal of the tumor was recommended, it was refused by the patient. Therefore, careful observation was continued as an out-patient until May 1979 when she noticed a temporal hemianopsia of her left eye. She was admitted and had partial removal of the tumor via frontal route and subsequent irradiation (total dose of 5,000 rad by Lineac). The tumor was verified to be a prolactinoma by the immunohistochemical staining. Postoperative course was uneventful and she lead a normal life. In Oct. 1981, severe faceache began and she was readmitted. Sella was destructed extensively and CT scan revealed a hugh sellar tumor with multi-directional extrasellar extension which was less enhanced than that of the first study. The serum PRL level was 588 ng/ml and the regrowth of prolactinoma was suspected. High dose bromocriptine (40 mg/day) therapy was started. The serum PRL level rapidly fell to the negligible value, however, shrinkage of the tumor was not observed. On Jan. 20, 1982, suddenly she developed a left hemiparesis and her level of consciousness gradually deteriorated. On Mar. 11, 1982, the second operation was performed and a solid firm tumor in the base of the skull was partially removed. The tumor was histologically verified to be a fibrosarcoma. After the second operation bromocriptine therapy was discontinued, however expected elevation of the serum PRL level was not recognized. She died on Apr. 4, 1982.

Adult↗

[An arachnoid cyst in the left lateral ventricle].

Generally arachnoid cysts are congenital in origin and found over the cerebral convexity, in the major fissures, and in the folded portions of the brain wherever the arachnoid membrane extends. Including other central nervous system (CNS) cysts, the location of these cysts has implications as to their origin, for examples, intracerebral cysts generally are ependymal cysts, while extracerebral cysts are mostly arachnoid cysts. An 8-month-old boy was admitted to our department because of enlarged head and developmental retardation. Computerized tomographic scan (CT) revealed remarkable hydrocephalus and a relatively high-dense, round lesion between the lateral ventricles. During surgery the cyst was found to arise from the left ventricular floor. Histologically the cyst wall was arachnoid membrane.

Arachnoid↗

[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↗

[Meningeal gliomatosis models as a chemosensitivity assay system].

Experimental models of meningeal gliomatosis (MG) have been produced by intracisternal inoculation of C6 and 9L glioma cells into Wistar and Fisher 344 rats, respectively. Chemotherapy of these models and in vitro chemosensitivity assay for these cell lines were studied with ACNU, BCNU and VM-26. In vitro chemosensitivity assay revealed that 9L cells were sensitive to all of the anticancer drugs above, and that C6 cells were resistant to ACNU and BCNU, but not to VM-26. In vivo experiment, the survival time of the rats inoculated with 9L glioma cells (9LMG) was prolonged by both ACNU and BCNU but not by VM-26. None of these drugs were effective against the rats inoculated with C6 glioma cells (C6MG). It is concluded that the result of in vitro chemosensitivity assay is not always correlative with that of in vivo. This implies that an in vivo chemosensitivity assay system including MG models is indispensable in researching into chemotherapy of brain tumor.

Animals↗

[Enhanced effect of reserpine on growth-inhibitory action of ACNU on ACNU resistance C6 glioma].

Reserpine was found to enhance the effect of ACNU on ACNU-resistant C6 glioma (C6/ACNU). When reserpine was added to the culture medium at the concentration of 10 microM, the IC50 of ACNU for C6/ACNU was decreased to the level of that for C6. Intracellular uptake of ACNU increased in both resistant and sensitive cells when 10 microM reserpine was added to the culture medium. This phenomenon is more remarkable in C6/ACNU than in C6.

Animals↗

[Local blood flow and capillary permeability in the experimental meningeal carcinomatosis].

Local blood flow and capillary permeability of the rats with meningeal carcinomatosis were studied with macroautoradiography, and relationship between blood flow, permeability and effects of chemotherapy is discussed. Experimental meningeal carcinomatosis was induced in the Wistar rats by inoculating Walker 256 tumor into cisterna magna. One to 12 days after inoculation, rats were used for measurements of blood flow (by 14C- iodoantipyrine) and capillary permeability (by 14C-alpha-aminoisobutyric acid). Images of autoradiography and corresponding histological appearances were analyzed. In the early stage of tumor growth (2 to 3 days after inoculation), a few layers of tumor cells were identified in the ambient cistern. Blood flow in the vicinity of the tumor cell layer was noted, but no increase in capillary permeability was found. In the middle stage of tumor growth (3 to 5 days after inoculation), 10 to 20 layers of the tumor cell was noted in the ambient cistern. Blood flow in the tumor was evident and capillary permeability began to increase. In the late stage of tumor growth (6 to 12 days after inoculation), a mass of the tumor cells was noted in the ambient cistern. In this stage, blood flow in the tumor was similar to that of cerebral gray matter and capillary permeability increased markedly. Brain adjacent to the tumor also showed increase in capillary permeability. The result correlated well to the previous result of experimental chemotherapy. Form those data, lipid soluble drugs which cross blood-brain barrier readily are recommended for the early stage of meningeal carcinomatosis, and water soluble drugs which has limitations to cross blood-brain barrier can not be recommended.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Development of ACNU-resistant meningeal gliomatosis models: establishment of resistant rat glioma subline against ACNU].

Induction in vivo of resistance of C6 rat glioma and 9L rat glioma to ACNU [1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride] was studied and ACNU-resistant rat meningeal gliomatosis models were developed by using these resistant glioma sublines. Rapid acquisition of resistance to the agent was present at 2nd transplant generation in both glioma lines. Cellular resistance to ACNU remained unchanged in the absence of drug over 5 transplant generations in vivo in spite of the fact that the drug treatment was discontinued at the 5th generation after a complete resistance was induced. On the other hand, the degree of resistance of 9L resistant subline established by only once ACNU treatment was found to be decreased after 5 transplant generations in vitro. Degree of resistance at the cellular level was observed with each subline by in vitro technique and compared with each other. Each subline was found to have different degree of resistance: 9L resistant subline showed higher resistance than C6 resistant subline, and the differences in degree of resistance between 9L resistant subline and C6 resistant subline were approximately 750 and 20, respectively, when they were expressed as ratios of IC50 (drug concentration for 50% growth inhibition) for the resistant subline to the original one.

Animals↗

Biphasic occurrence of delayed ischemia after early aneurysm surgery. Case report.

An unusual case of delayed ischemia following rupture of an aneurysm of the left internal carotid artery is reported. Symptoms occurred twice after clipping the aneurysm and removing most of the subarachnoid blood on the left side the day after subarachnoid hemorrhage (SAH). Initial ischemia due to vasospasm occurred on the left side of the brain on the 8th day after SAH and responded favorably to induced hypervolemia. After complete recovery, a second episode due to vasospasm occurred on the 16th day after SAH on the right side of the brain from which the subarachnoid blood had not been removed. This caused a massive lesion and permanent severe neurological deficits. This case suggests that removal of subarachnoid blood may affect the severity and time course of vasospasm, and emphasizes the necessity of extensive removal of subarachnoid blood for prevention of severe delayed ischemic symptoms.

Carotid Artery Diseases↗

Changes of the blood-brain barrier in experimental metastatic brain tumors.

An experimental model for blood-borne cerebral metastases was developed by introducing Walker 256 carcinoma cells selectively into the intracranial internal carotid artery of rats. This model was used to study the regional capillary permeability of rat brain and metastatic brain tumors of various sizes with the aid of 14C alpha-aminoisobutyric acid (AIB) quantitative autoradiography. The regional capillary permeability varied with the anatomical location and size of the tumor. Intraparenchymal tumors less than 1 mm in diameter showed no increased permeability to AIB. As the tumors enlarged over 1 mm in diameter, the permeability in the intraparenchymal tumors increased proportionally, but remained less than one-third of capillary permeability of subcutaneously transplanted tumors. Capillary permeability in the peripheral invasive part and necrotic center was less than in the viable part of large tumors. Capillary permeability in metastatic tumors of the choroid plexus and meninges was significantly higher than in tumors of the brain parenchyma. The results suggest that the uptake of chemotherapeutic agents that do not cross the blood-brain barrier easily varies with the anatomical location and size of the metastatic tumors.

Animals↗

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↗

[Primary culture of human functioning pituitary adenoma in monolayer and collagen gel culture].

Human functioning pituitary adenomas (3 acromegalies, 3 prolactinomas) obtained at transsphenoidal hypophysectomy were dispersively embedded inside collagen gels and subjected to the conventional monolayer culture in Eagle's MEM medium containing fetal bovine serum. Basal secretion of growth hormone (GH) and prolactin (PRL) in the media of monolayer and collagen gel cultures were measured by radioimmunoassay (RIA) for 5 weeks. GH secretion in the culture media was initially high in all cases with acromegaly in both monolayer and collagen gel cultures. GH secretion in monolayer culture declined rapidly almost as a straight line on a semilogarithmic scale until 5 weeks, when GH level decreased around 10 ng/ml. GH secretion in collagen gel culture was preserved more than in monolayer culture, but declined slowly up to about 500 ng/ml within 5 weeks. PRL secretion in monolayer culture initially declined rapidly until 1 week, but after then remained constant or decreased slowly. In the other hand, PRL secretion in collagen gel culture remained almost constant for up to 5 weeks. It is concluded that this new culture method may provide suitable conditions for maintenance of the adenomas cells in vitro.

Adenoma↗