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Biomedical subjects

E Moriyama

Publications and source records attributed to E Moriyama.

11 recordsLinked to original sources
PubMed1992

Six strains of human immunodeficiency virus type 1 isolated in Japan and their molecular phylogeny.

Five strains of human immunodeficiency virus type 1 (HIV-1) were isolated from five Japanese hemophilia patients. Two isolates, HIV-1[GUN-1] and HIV-1[GUN-2], were from brother patients with hemophilia B and the other three isolates, HIV-1[GUN-3], HIV-1[GUN-4], and HIV-1[GUN-5], were from hemophilia A patients. Another HIV-1 strain, HIV-1[GUN-6], was isolated from a Canadian male homosexual with AIDS. The restriction endonuclease cleavage maps of the proviral genomes of these six HIV-1 strains revealed that they were apparently different from each other. The phylogenetic trees constructed using restriction maps and nucleotide sequences were quite similar, indicating that phylogenetic analyses of Japanese HIV-1 isolates can be done using restriction maps of the proviruses. Phylogenetic analyses showed that they were more closely related to HIV-1s which had been reported to be isolated from homosexual patients in the United States than those isolated from African patients. In particular, GUN-1 and GUN-2 isolates were on the branch of a San Francisco isolate, ARV2, while GUN-5 and GUN-6 isolates were on the branch of HTLV-IIIB-related isolates.

AIDS-Related Complex↗
PubMed1992

Cerebral sinus thrombosis in patient with ulcerative colitis--case report.

Left transverse sinus thrombosis developed in a 27-year-old male with ulcerative colitis. The diagnosis was based on cerebral angiography and magnetic resonance (MR) imaging, the latter of which clearly delineated the intraluminal thrombus. Serial MR images demonstrated thrombus organization. The use of this method in the diagnosis of cerebral sinus thrombosis might reduce the need for cerebral angiography.

Adult↗
PubMed1992

[Analysis of long-term social rehabilitation of brain contusion].

164 patients with brain contusion were evaluated with respect to social rehabilitation. 70 out of 134 patients (66.7%), said to have had good recovery or moderate disability by the Glasgow Outcome Scale (GOS), returned to full or partial employment. Factors such as age, Glasgow Coma Scale (GCS) at admission, duration of unawareness, fibrin and fibrinogen degradation product (FDP) were the most important in predicting social recovery. The Wechsler Adult Intelligence Scale (WAIS) was applied in 33 patients. The IQs of the patients who returned to their job fully tended to be higher than those who could not. In the majority of patients, impaired capacity for work was caused not only by physical deficits, but by mental retardation described as such as IQ score.

Adolescent↗
PubMed1991

Blood-brain barrier alteration after microwave-induced hyperthermia is purely a thermal effect: I. Temperature and power measurements.

The effect of microwave-induced hyperthermia on the blood-brain barrier was studied in 21 Sprague-Dawley rats. Under sodium pentobarbital anesthesia, animals were place in a stereotactic frame, and an interstitial microwave antenna operating at 2450 MHz was inserted in a bony groove drilled parallel to the sagittal suture. Some antennae were equipped with an external cooling jacket. Temperature measurements were made lateral to the antenna by fluoroptical thermometry, and power was calculated from the time-temperature profile. Five minutes prior to termination of microwave irradiation, horseradish peroxidase (1 mg/20 g body weight) was injected intravenously. Extravasation of horseradish peroxidase was observed in brain tissue heated above 44.3 degrees C for 30 minutes and at 42.5 degrees C for 60 minutes. Microwave irradiation failed to open the blood-brain barrier when brain temperatures were sustained below 40.3 degrees C by the cooling system. Extravasation of blood-borne peroxidase occurred at sites of maximal temperature elevation, even when these did not coincide with the site of maximum power density. The data suggest that microwave-induced hyperthermia is an effective means for opening the blood-brain barrier and that the mechanism is not related to the nonthermal effect of microwaves.

Animals↗
PubMed1990

Cerebral blood flow changes during localized hyperthermia.

Hyperthermia is becoming a potent therapeutic method for malignant brain tumors, either alone or in combination with radiation therapy. The heat response of organized tissues includes other factors besides the inherent cellular thermosensitivity, that is, tissue pH, PaO2, and nutrient supply, all of which are largely influenced by the tissue blood flow. In this study, the regional cerebral blood flow (rCBF) changes in 15 Japanese normal monkey brains during interstitial microwave hyperthermia were investigated by the hydrogen clearance method. Under general anesthesia and controlled respiration, a parieto-occipital craniectomy, 4 x 4 cm, was performed. A microwave antenna was inserted into the brain to a depth of 2.0 cm, and the brain tissue was heated with 2450 MHz microwave irradiation. The intracerebral temperatures and rCBF were measured in the white matter 1 cm from the brain surface. During hyperthermia, the rCBF linearly increased at a rate of 10% per 1 degrees C temperature rise. Heating at 42 degrees C for 180 minutes resulted in a constant increase in rCBF. The perfusion rate returned to the control levels after the termination of heating. Above 45 degrees C, the rCBF transiently increased and then started to decline during heating. No consistent results were obtained with heating at 43 degrees C. These results show that normal monkey brain tissues respond to hyperthermia by an rCBF increase as long as the threshold values of tissue temperature (43 degrees C) and exposure time (40-60 minutes) are not exceeded. Excessive heating may lead to irreversible damages to normal tissue and vasculature.

Animals↗
PubMed1989

Cerebral blood flow and the thermal properties of the brain: a preliminary analysis.

Safe and effective use of hyperthermia for the treatment of brain tumors requires precise control of the distribution of temperatures (that is, the thermal field) within the tumor and within the adjacent brain. Major influences upon the distribution of temperatures include the passive thermal properties of the brain, such as its specific heat (Cb), and the contribution of cerebral blood flow (CBF). Recently, an electrical-mechanical analog model of heat flow within the brain has been developed from which an expression for CBF has been derived: CBF = Cb/(tau rho c) where tau is the thermal decay constant, rho is the density of blood, and c is its specific heat. To test this model a series of experiments was carried out in adult dogs in which stereotaxically implanted microwave antennas operating at 2450 MHz, fluoro-optical thermometry probes, and platinum electrodes were used to simultaneously measure CBF by thermal washout and hydrogen clearance techniques. The correlation coefficient for estimates of CBF derived by the two methods in 52 paired observations was 0.89. Measurements of CBF were more reliable at increased distances from the microwave antenna, since CBF is sensitive to the degree of temperature elevation (delta T). The ratio of post-heating CBF to pre-heating CBF varies linearly with delta T and has a correlation coefficient of 0.86. When values of CBF determined by the hydrogen clearance method were employed in the above equation, it was possible to derive Cb as 0.70 +/- 0.08 cal/gm-degrees C. Use of this value for Cb in this equation produces estimates of CBF by thermal clearance that are within 10% of the values for CBF as measured by the hydrogen clearance method. It is concluded that this model of thermal flow within the brain may have heuristic value for treatment planning and that microwave antennas and fluoro-optical probes may represent a new methodology for the clinical estimation of CBF. These methods have recently been employed in patients undergoing combined hyperthermia and chemotherapy.

Animals↗
PubMed1988

Hyperthermia for brain tumors: improved delivery with a new cooling system.

Hyperthermia has emerged as an adjunct to other forms of brain tumor therapy. Interstitial microwave irradiation is an effective method of inducing localized brain hyperthermia. One of the problems with this technique, however, is the overheating of tissue adjacent to the antenna. In this study, a cooling system for the interstitial microwave antenna was developed for the purpose of providing uniform and accurate heating by the elimination of overheating. The ability to generate more uniform hyperthermic fields was evaluated in normal monkey brains. Six monkeys under general anesthesia and controlled respiration underwent parietooccipital craniectomies 4 x 4 cm in size. The antenna cooling system was constructed of a silicone tube 5.0 mm in outer diameter. Silicone-coated interstitial microwave antennae 1.5 mm in diameter were used. A single antenna or a square array (1.6 cm on a side) of 4 antennae was inserted into the brain with the coupled system to a depth of 2 cm. The brain tissue was heated by 2450-MHz microwave irradiation. Temperature distributions were mapped using nonperturbing thermocouples. These thermal profiles were compared with those generated without the cooling system. In the experiments with the single antenna, the antenna cooling system eliminated the overheating and rapid radial falloff in temperature, without a reduction of the hyperthermic field. In the four-antennae experiments using the cooling system, the thermal field was dramatically flattened with minimal reduction in size; however, the area maintained at a therapeutic temperature range (42-45 degrees C) was significantly enlarged by the cooling system.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Fundamental study of differential hypothermia treatment of brain tumor using an interstitial microwave antenna].

An interstitial microwave antenna system was devised for differential hypothermia treatment. It was evaluated for its ability to induce localized brain hyperthermia in hypothermic monkey. Ten brain hyperthermia trials have been performed in 6 monkeys. Under general anesthesia, the animals were put into ice water bath to keep the total body temperature at 30 degrees C. Following parieto-occipital craniectomy, a microwave antenna of 1.5 mm in diameter was inserted into the brain at depth of 2 cm, and the brain tissue was heated by 2450 MHz microwave irradiation. Thermal distribution was measured by thermistor probes and local cerebral blood flow (1-CBF) before and after heating was simultaneously measured by hydrogen clearance method. After the experiment, the animals were sacrificed and histopathological changes of the heated brain tissue were studied. Under total body hypothermia of 30 degrees C, the maximum cross-sectional diameter of the heated brain to 37 degrees C or above was about 4 cm. The temperature profile on the vertical plane presented a bell-shaped distribution. The 1-CBF of the heated brain increased with the elevation of the brain temperature and the blood flow at 37 degrees C is nearly twice as much as that of 30 degrees C. After one hour DH treatment, necrotic tissue was noted along the antenna axis where the temperature was maintained more than 50 degrees C, and this change was not recognized at a distance of 1 cm from the antenna where the temperature was maintained at 42 degrees C. This study indicates that interstitial microwave hyperthermia system can be used effectively to heat the localized brain tissue.

Animals↗
PubMed1986

Lymphoid adenohypophysitis.

A rare case of lymphoid adenohypophysitis in a 28-year-old woman with temporal relation to pregnancy is described. A CT scan disclosed a round, contrast-enhancing sellar mass simulating pituitary adenoma, and endocrine evaluation showed mild hypopituitarism. Histological examination of the specimen obtained by transsphenoidal hypophysectomy after uneventful natural labour showed marked diffuse infiltration of mature lymphocytes with many germinal centers within lymphoid follicles. This finding was the same as previously reported. The present case makes a total of 15 cases reported in the world literature up to date. To our knowledge, no report has been documented in Japan.

Adenoma↗
PubMed1985

Present role of stereotactic thalamotomy for parkinsonism. Retrospective analysis of operative results and thalamic lesions in computed tomograms.

14 cases of unilateral and 5 cases of bilateral thalamotomy for parkinsonism were reviewed, with 32-144 months' (mean 67.8) and 54-212 months' (mean 110) follow-up, respectively, after the initial operation. Rigidity and tremor disappeared in approximately 80% of cases and was reduced in the remaining 20%. 68% improved by one or two grades in the Hoehn-Yahr scale after operation. Thalamotomy abolished dyskinesias and on-off phenomena on the operated sides. 36% of cases discontinued levodopa therapy after operation. CT study of the lesions suggested that destruction of a large part of basal Vop was most important to obtain the best results.

Adult↗