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Biomedical subjects

M Arima

Publications and source records attributed to M Arima.

At least 163 records · Page 9Linked to original sources

The protective effects of vitamin E against microcephaly in rats X-irradiated in utero: dendritic branches.

Fetuses from rats given either water or 0.03% dl-alpha-tocopherol acetate (vitamin E) as the drinking fluid and X-irradiated with 100R on gestational day (gd) 13 were examined on gd 21. The degree of dendritic branching of frontal cerebral neurons, examined after Golgi staining, was significantly reduced by X-irradiation, and supplementation of vitamin E caused increased branching order numbers in irradiated fetuses. This study provides evidence of the protection by vitamin E of neuronal development in X-irradiated fetuses.

Abnormalities, Radiation-Induced↗

Superoxide dismutase in fetal rat cerebrum X-irradiated in utero.

The superoxide dismutase (SOD) activity in fetal rat cerebrum was studied on gestational days (gd) 19 and 21 after X-irradiation with 100R on gd 13 or no X-irradiation. Fetuses X-irradiated on gd 13 showed marked microcephalus on gd 19 and 21. Most of the SOD activity was found in the crude mitochondrial fraction in both groups and most of the SOD was Cu,Zn-SOD. The SOD activity increased about two times from gd 19 to 21. The mean SOD activity of the fetal rat cerebrum X-irradiated with 100R showed no significant differences compared to that of the control group with Student's t test. But the activities in the irradiated group were widely distributed with a large standard deviation and so the chi-square test showed a significant difference in SOD activity between the two groups on gd 19. The SOD activity of adult rat cerebrum 6 and 8 days after X-irradiation with 100R was increased compared to that 3 days after X-irradiation. It was suspected that X-irradiation in utero may have some lasting effect on the SOD activity in fetal rat cerebrum.

Animals↗

Increased cadmium resistance of skin fibroblasts from Menkes disease patients.

Cultured skin fibroblasts from patients with Menkes disease and Wilson disease were analyzed as to their sensitivities to copper and cadmium by means of a colony-forming ability and cell growth study. All the Menkes strains exhibited about 3-fold higher levels of resistance to cadmium, whereas the cytotoxicity of copper did not differ among the Menkes, Wilson and normal fibroblast strains. The resistance to cadmium of Menkes skin fibroblasts may provide a diagnostic marker of Menkes disease and useful or valuable model for the understanding of detoxification system against heavy metals.

Brain Diseases, Metabolic↗

Rett's syndrome: progression of symptoms from infancy to childhood.

The results of studies of seven girls with Rett's syndrome and two additional cases suggestive of Rett's syndrome are presented. After normal neurological development up to the age of 7 to 20 months, there was a rapid regression of higher cortical function. Rett's syndrome was initially manifested by a delay of further motor development and the appearance of autistic traits. As the disease progressed, there was a loss of ability to crawl, loss of purposeful hand movements, abnormal respirations, truncal ataxia, seizures, and spastic increase in muscle tone. Blood chemistries, including ammonia levels, were normal. Metabolic interference, a recently hypothesized form of inheritance, may occur in this syndrome.

Adolescent↗

Cerebro-oculo-hepato-renal syndrome (Arima' syndrome): a distinct clinicopathological entity.

Three children with Leber's congenital amaurosis, agenesis of the cerebellar vermis, and infantile polycystic kidneys are described. The common clinical findings of three unrelated patients (two boys and one girl) included severe visual impairment from early infancy, profound psychomotor retardation, hypotonia, nystagmus, characteristic facial appearance with blepharoptosis, and progressive chronic renal insufficiency. The two boys died of uremia at ages 13 and 12 years. The common pathological findings in these two patients consisted of minor disproportions of cerebral lobes, almost total aplasia of the cerebellar vermis, micropolygyria of the dentate nuclei, malformations of the brain stem (including pachygyria of the inferior olivary nuclei and partial absence and anomalous position of the pyramidal tracts), and infantile polycystic kidneys; there was fatty liver in one case and hepatic fibrosis in the other. The clinicopathological findings of our two patients were entirely compatible with those of patients previously reported by Arima and other Japanese authors. Therefore, these patients seem to comprise a distinct clinicopathological entity, cerebro-oculo-hepato-renal syndrome (Arima's syndrome), different from other syndromes with retinal, cerebellar, and renal abnormalities.

Blindness↗

Conversion of pyridoxine into 6-hydroxypyridoxine by food components, especially ascorbic acid.

In experiments designed to examine interactions between pyridoxine (PN) and food components, PN was found to be converted into an unidentified compound in the presence of the homogenates of various plant foods under mild conditions. The formation of the compound tended to be higher when food samples had a higher ascorbic acid (AsA) content. The reaction was neither thermal decomposition nor photodecomposition. This compound was also formed by incubating PN with AsA in the dark. Conversion of PN into the compound proceeded with oxidation of AsA, and was negligible under anaerobic conditions. The pH optimum for the reaction was between 4 and 7, and the temperature optimum was between 30 and 50 degrees C. The compound was purified by ion-exchange chromatography, isolated as colorless needles, and identified as 6-hydroxypyridoxine from UV, PMR, IR and MS spectral data. 6-Hydroxypyridoxine had neither vitamin B6 nor antivitamin B6 activity for Saccharomyces carlsbergensis 4228 (ATCC 9080). From these results, we inferred that hydroxylation of PN in the presence of food components, especially AsA, caused loss of vitamin B6 in plant foods during food processing, storage and cooking.

Ascorbic Acid↗

[Clinical statistics on outpatients, inpatients and operations in 1984].

Statistical studies on 1,893 outpatients, 538 inpatients and 554 operative procedures at our department in 1984 revealed the following. The most frequent diseases among the outpatients were urogenital infections followed by anomalies, tumors and stones. The major diseases among the inpatients were hypospadias, vesicoureteral reflux, benign prostatic hypertrophy, bladder tumor and congenital urethral stenosis. A total of 554 operations were performed on 534 patients, and five major operations were hypospadias repair (68), ureterocystoneostomy (57), optic internal urethrotomy (50), TUR-P (42) and TUR-Bt (33).

Adolescent↗

[Copper-binding proteins in liver, kidney and brain tissue from a Wilson's disease patient].

Copper-binding proteins (Cu-PBs) in the liver, kidney, and brain tissues from a Wilson's disease patient, who was 19-year-old woman and died of hemolytic crisis, were examined with Sephadex G-75 gel chromatography and SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Copper contents, which were determined by flameless atomic absorption spectrophotometry in the liver, kidney, and cerebral tissues from the patient, were 28-, 38-, and 3.5-fold, respectively, as compared to those of control subject, who was 5-year-old girl and died of cerebral palsy. Each tissue was homogenized in 3 volumes of 50 mM Tris-HCl buffer, pH 8.6, and the homogenate was centrifuged at 105,000 g for 60 min to obtain cytosol fraction. Sephadex G-75 gel chromatography of cytosols from Wilson's liver and kidney showed that most of increased copper existed as Cu-thionein (Cu-Th), in contrast to a much lower Cu-Th level in control liver cytosol and to no detectable amount of Cu-Th in control kidney cytosol. In addition, Zn-Th was also increased in Wilson's kidney cytosol, while it was decreased in Wilson's liver cytosol. Gel chromatography of Wilson's cerebral cytosol revealed that the increased copper bound mainly to two proteins with apparent molecular mass of 10 kDa (Cu-BP 1) and 20 kDa (Cu-BP 2), respectively, both of which showed no absorption at 280 nm and were not observed in control cerebral cytosol even after addition of excess copper (50 micrograms/ml) as CuSO4.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Determination of collagen band positions on polyacrylamide gel without staining.

Protein band positions on a slab polyacrylamide gel were determined without staining, by blotting the bands onto a nitrocellulose membrane which was then stained to visualize the electrophoretic pattern. The unfixed, unstained bands were cut from the gel according to the copy pattern placed underneath the slab gel. Collagen alpha 1 and alpha 2 chains were separately extracted from the gel using this procedure.

Amino Acids↗

Effects of dimethylsulfoxide on sphingomyelinase in cultured human fibroblasts and correction of sphingomyelinase deficiency in fibroblasts from Niemann-Pick patients.

The effects of dimethylsulfoxide (DMSO) on sphingomyelinase activity were studied using human skin fibroblasts from normal individuals and Niemann-Pick patients. Sphingomyelinase activity in normal fibroblasts increased up to 230% of controls by 2% DMSO while the cell growth was inhibited. Other lysosomal hydrolases showed a rather smaller extent of increment in activity. There was no direct effect of DMSO in cell-free system and no evidence of any activating factor of sphingomyelinase in homogenates. Sphingomyelinase deficiency in fibroblasts from a Niemann-Pick patient (type C) was corrected by 2% DMSO with regaining its enzyme activity.

Cell Division↗

Two siblings with multiple intracranial haemangiomatosis with calcification.

Two siblings with multiple intracranial haemangiomatosis are reported, each having psychomotor retardation, epilepsy and gyriform type calcification in the occipital and frontal lobes. There were haemangiomas in one autopsy case with calcification in the deep layers of the cortex and subcortical white matter.

Brain Diseases↗

Rapid rejoining of X-ray-induced DNA single-strand breaks in tuberous sclerosis fibroblasts.

The formation and rejoining rates of X-ray-induced DNA single-strand breaks (SSBs) were examined in radiosensitive and non-radiosensitive fibroblast lines from patients with tuberous sclerosis (TS), and fibroblasts from normal individuals, using the sensitive and quantitative alkaline elution method. No difference was found between these cell lines in the frequency of DNA SSBs directly produced by X-irradiation at any dose up to 750 rad. Kinetic analysis of the rate of rejoining of DNA SSBs after X-irradiation at 500 rad indicated that the rate of rejoining involved at least two components, an initial fast component and a slower component. TS fibroblast lines, either radiosensitive or nonsensitive, were proficient as to DNA SSB repair, but they showed an increased rate of rejoining in the initial fast repair process, when compared to normal fibroblast lines. Although the molecular basis for the accelerated rejoining of DNA SSBs remains unknown, it is possible that the abnormality may be related to a basic defect in TS.

Adolescent↗

Effects of combinations of maternal agents on the fetal cerebrum in rat--ethanol or caffeine with X-irradiation in utero.

Fetal cerebral development influenced by maternal ethanol or caffeine either singly or in combination with X-irradiation was investigated in rat. Female Wistar rats were given 20% ethanol, 0.04% caffeine and water during the premating period and pregnancy, and 0.03% vitamin E only during pregnancy. Pregnant rats were X-irradiated with 100R or sham-irradiated on gestational day 13. Ethanol-treatment alone much reduced the fetal body and cerebral weights, and X-irradiation alone resulted in great reductions in weight and DNA concentration in the fetal cerebrum. The reduction in body weight with ethanol exceeded that with X-irradiation, therefore, the addition of X-irradiation had no effect on that of ethanol. The reduction in cerebral weight on X-irradiation exceeded that with ethanol, thus the addition of ethanol had only a slight effect on that with X-irradiation. The decrease in body and cerebral weights and the increase in lipid peroxide (LP) formation on caffeine-treatment and the decrease in cerebral weight and the increase in LP on vitamin E-treatment were inhibited by X-irradiation as compared to the combined effects of the other drink treatments. The increase in placental weight and the decrease in cerebral weight on ethanol-treatment and the decrease in placental, body and cerebral weights on caffeine-treatment, which findings were covered by the addition of X-irradiation, became much clearer on single drink treatment. Independently of X-irradiation, ethanol-treatment resulted in increased fetal mortality and LP, and decreased body weight. These results suggest that the combined effects of maternal agents on live fetuses should be investigated as to whether they act independently of or dependently with each other and how the effects appear either singly or mixed.

Animals↗