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Biomedical subjects

H Higuchi

Publications and source records attributed to H Higuchi.

At least 325 records · Page 18Linked to original sources
PubMed1979

[Determination of radioactive and stable cobalt in marine biological materials (author's transl)].

Studies were made to develop the method for rapid determination of radioactive and stable cobalt in a single specimen of marine biological materials. The sample was dried, ashed, and dissolved in acid. The cobalt was extracted with 1-nitroso-2-naphthol benzene and determined by absorptiometry on the benzene phase. Then, the organic solution was evaporated to dryness, and the residue was treated with nitric-perchloric acid mixture to decompose any organic matter, and taken up with hydrochloric acid. The cobolt was extracted from the solution with TIO A-toluene, and the radioactive cobalt was determined by liquid scintillation counting on the toluene phase. Examinations were made on the chemical yield and on the decontamination factor of the fission product nuclides. Analysis were made on the marine biological samples of Urazoko Bay, Fukui prefecture. Agreement of the radioactive cobalt data between that by the present method and that by Ge(Li) gamma ray spectometry was good. Also, the stable cobalt value by the present method agreed well with that by neutron activation analysis method.

Animals↗
PubMed1979

[Cryptococcal granulomatous arachnitis of the spinal cord--a case report (author's transl)].

A case of cryptococcal granulomatous arachnitis of the spinal cord was reported. A 12-year-old boy suffered from sudden occipitalgia and left hemiparesis. The symptoms disappeared spontaneously in about a half year. The next year, he consulted an orthopedist because of lumbago and gait disturbance. Myelography through the cisternal route showed complete block at the level of L1. Exploratory laminectomy of D12 and L1 revealed adhesive arachnitis. Symptoms were improved immediately after the operation. At the age of 15, he was admitted to our clinic, because of sudden onset of headache and vomiting. Computed tomography showed marked hydrocephalus. He recovered by ventriculoperitoneal shunt, and was discharged. The next year, sudden back pain occurred. Gait disturbance, sensory disturbance of the legs and trunks below the mamilla, and dysuria appeared gradually. He was readmitted and laminectomy of D2-4 was performed. The arachnoid membrane was white and 2 mm in thickness diffusely. Thickened arachnoid membrane was removed at the level of D2-4. Histological diagnosis was granulomatous arachnitis. Cryptococcus was seen in the removed tissue. Symptoms were improved after operation. One thousand milligrams of amphoterisin B was injected intermittently. He was discharged on food. Spinal symptoms in cryptococcosis are rare. Operative procedures were effective before the administration of amphoterisin B.

Adolescent↗
PubMed1978

[Residual radioactivity measurement for high purity silicon irradiated by pile-neutron (author's transl)].

Residual radioactivity measurement is described for high purity silicon (purer than tennine) irradiated by pile-neutron to produce n-type silicon semiconductor. The silicon samples were irradiated in four different atomic reactors with thermal neutron fluxes of 0.12, 1.48, 1.8 and 5.5 X 10(13) n/cm2. sec. After irradiation, the sample was dissolved in HF-HNO3, and the solution dried. The residual radioactivity was measured by a 2pi gas-flow low background GM counter. The only active species found was 32P, which was formed by the consecutive reaction of 30Si(n, gamma)31Si beta- leads to 31P followed by 31P(N, GAMMA)32P. The observed production rate for 32P was in good agreement with the calculated one. This technique can be applied to estimate amounts of not only doped phosphorus but impurities such as gold in irradiated silicon. Tail part of a float-zone silicon rod contained about 0.01 atomic ppb of Au, but no activity was observed in its middle part. The present technique is suitable for checking and characterizing silicon rods before their neutron-doping.

Neutrons↗
PubMed1978

[A case of aneurysm of the left internal acoustic meatus (author's transl)].

A case of aneurysm of the left internal acoustic meatus has been reported. The patient was 53-year-old man who was admitted with the history of sudden onset of a severe occipital headache 18 days previously. He also noted nausea, vomiting and became drowsy at that time. He was seen at a local clinic and a lumbar puncture showed bloody fluid. The next day his level of consciousness improved but he noted left tinnitus and neck stiffness. On admission, he only complained of a left tinnitus. The rest of the neurological examination was normal. Craniogram was of no abnormal findings. Cerebral angiogram showed an aneurysm at the left internal acoustic meatus fed by the left internal auditory artery. At operation, the aneurysm was clipped at the entrance of its feeding artery via retroauricural-retromastoidal craniectomy. The postoperative course was satisfactory except for the decrease of the left auditory acuity to 50dB. Postoperative angiogram revealed a complete disappearance of the aneurysm. In the literature only six cases have been reported, which were summarized in Figure 1. Clinical features of such an aneurysm are subarachnoid hemorrhage and symptoms of cerebello-pontine angle, namely tinnitus, hearing disturbance and facial palsy etc. Besides, on skull x-ray film, sometimes enlargement of the internal acoustic meatus has been found.

Ear, Inner↗
PubMed1976

Allende meteorite: Isotopically anomalous xenon is accompanied by normal osmium.

The (184)Os/(190)Os ratio of six Allende meteorite samples was determined by neutron activation analysis. Four chromite concentrates gave a ratio differing from the terrestrial ratio by only -0.1 +/- 0.4%, although they contained highly anomalous xenon enriched by up to 67% in (124)Xe and 93% in (136)Xe. In view of this result and the normal isotopic composition of carbon and oxygen in these fractions, it seems very unlikely that the xenon anomalies were produced in a supernova by the p and r processes. More probably, the xenon anomalies were established in the early solar system, by mass fractionation during trapping of noble gases in solids and by spontaneous fission of a superheavy element.Two other samples, containing osmium from the calcium,aluminum-rich inclusions, also gave an (184)Os/(190)Os ratio within -0.1 +/- 0.5% of the terrestrial value, although these inclusions show well-established anomalies in the light elements oxygen and magnesium, which appear to be due to pre-solar dust grains of distinctive nuclear history. Apparently the stellar source of the anomalous oxygen and magnesium did not synthesize heavier elements.

Journal Article↗
PubMed1976

[Rapid determination of 137Cs in environmental samples--purification of 137Cs by ammonium molybdophosphate column separation].

A rapid method for the determination of 137Cs in environmental samples was proposed. The principal technic employed in this study is based on column separation of 137Cs using ammonium molybdophosphate mixed with glass fiber to eliminate contribution of natural radionuclides such as 40K and 87Rb. The separation of cesium from potassium and rubidium was performed by the elution with 0.5m ammonium nitrate solution. The time required for separation of cesium was five hours as compared with the conventional cation exchange separation which required thirteen hours. The chemical yield of cesium carrier was normally more than 90 percent. The results obtained were compared with that by the conventional methods using Bio-Rex cation exchange separation and the good agreement between the two methods was obtained.

Animals↗
PubMed1976

[Influences of deviations of thyroid functions on the effects of MAOI in rats--changes of 5-HT, 5-HIAA and norepinephrine contents and tyramine uptake by the brain and fluctuation of the rectal temperature].

Influences of hyper- and hypothyroidism on MAOI (tranylcypromine) were studied by measuring the effects on rectal temperature and 5-HT, 5-HIAA and norepiniphrine levels and tyramine uptake in the brain. Hyperthyroidism was accomplished in rats injected with triiodothyronine 0.2 mg/kg i.p. every two days for 70 days (long period group) or every day for 5 days (short period group) and hypothyroidism induced by feeding rats a diet to which 0.3% propylthiouracil had been added for 70 days (long period group) or 30 days (short period group). Those controls were treated with a triiodothyronine vehicle 1.0 ml/kg i.p. and fed a normal-balanced diet for each period. All the long period groups were decapitated on the last day and the brains were used for the determination of steady levels of above-cited monoamines. The 5-HT content in hypothyroid rats was considerably higher than euthyroid rats but other determinations in both hyper- and hypothyroid rats did not differ significantly in comparison with euthyroid controls. Each short term group was treated with tranylcypromine 10 mg/kg i.p. on the last day. Tranylcypromine brought about a marked hyperthermia in hyperthyroid rats but conversely hypothermia in hypothyroid rats, while "MAOI-induced 5-HT and norepinephrine increase, 5-HIAA decrease and tyramine uptake inhibition in the brain" of hyper- and hypothyroid rats were almost to the same in degree as in euthyroid rats.

Animals↗