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Biomedical subjects

H Seki

Publications and source records attributed to H Seki.

At least 289 records · Page 16Linked to original sources
PubMed1984

Circadian changes of T lymphocyte subsets in human peripheral blood.

The circadian variations in circulating T cell subsets defined by monoclonal antibodies in eight healthy male volunteers were evaluated in whole blood using a flow cytometry. In all subjects, the number of lymphocytes showed a clear rhythmicity with high values at night and low values during the day. This circadian variation in circulating lymphocytes appeared to reflect largely a change in the number of T cells rather than B cells. The percentage of OKT3+ and OKT11+ cells showed a similar fluctuation with a peak at night and a depression during the day. It was found that the percentage of OKT4+ cells varied in parallel with that of T cells, particularly of OKT3+ cells, but the OKT8+ subset was not appreciably altered over a 24 h period. Thus, a circadian variation of T cells could be largely accounted for by a circadian change of OKT4+ cells. Plasma cortisol levels showed an expected circadian variation. It was also shown that there might be an intimate relationship between these circadian changes of T cell subsets and plasma cortisol levels.

Adult↗
PubMed1983

Chronological relationship between neurological signs and electrophysiological changes in rats with methylmercury poisoning - special reference to selenium protection.

In order to see chronological relationship between electrophysiological changes and "early" neurological sign (tail rotation) elicited in rats poisoned with methylmercury, we made serial measurements of amplitude of compound action potential and sensory nerve conduction velocity of the tail nerve in rats with five dose schedules [methylmercury vs selenium, (1)20 ppm:0.1 ppm, (2)20: 0.3, (3)20: 0.6, (4)10: 0.1, (5)10: 0.6]. We observed the following sequence in the onset of neuro-electro-physiolo-somatic signs: fall in compound action potential greater than decrease in sensory nerve conduction velocity greater than tail rotation greater than weight loss. Protective potency of dietary selenium against neurotoxicity of methylmercury was observed with regard to both electrophysiological changes and neurological signs.

Action Potentials↗
PubMed1983

Influence of music on memory and education, and the application of its underlying principles to acupuncture.

The interrelations among learning, brain waves, music and the relief of pain by acupuncture are discussed from the standpoint of an educator, who has some practical experience in suggestive-accelerative learning and teaching (S.A.L.T.). Through the diverse fields of science, e.g. educational psychology, physiology, electronics and acoustics, the principal law governing the l/f fluctuations (where f is frequency), or the inverse frequency distribution of the power spectrum, seems to play an important role in their phenomenological mechanism. The author totally explained in this paper such relations and he arranged the related phenomena into physical, physiological, psychological and pedagogical fields. Finally, he referred to an interesting example of the application of l/f fluctuations to the relief of pain by acupuncture.

Acupuncture Therapy↗
PubMed1983

[Multiple brain tumors with von Recklinghausen's disease].

Thirty-three cases of von Recklinghausen's disease, nine of which had multiple brain tumors, were experienced in our clinic. In this report, these nine cases were reported and discussed, especially representative two cases in detail. Nine cases had various combinations of multiple brain tumors: bilateral acoustic neurinomas in two cases, multiple neurinomas in two cases, multiple meningiomas in one case and multiple neurinomas and meningiomas in two cases. In two cases, multiple brain tumors were totally extirpated at one stage, but both died within ten months. In three cases, partial extirpation of multiple brain tumors were performed at one stage, one died thirteen years after the operation and two are alive but dependent on their families. In recent two cases, two stage operations were performed, by which tumors were successfully removed totally. These postoperative courses were good. The other two cases were treated conservatively. One is alive and working, but has severe auditory disturbance. The other died after six years from onset. Autopsy was performed in this case, which revealed multiple neurinomas in the left 3rd and bilateral 5-12th cranial nerves and numerous meningiomas. In the review of the cases with more than three brain tumors in von Recklinghausen's disease were discussed.

Adult↗
PubMed1983

[Hemodynamics in hemorrhagic infarction--an experimental study].

Using our previously reported "thalamic infarction model in the dogs", it was found that hemorrhagic infarction can be produced at a high frequency following recirculation after 6-12 hours of vascular occlusion. In the present study, in order to elucidate the pathophysiology of hemorrhagic infarction, we have undertaken a study of the relations among the histological findings, degree of ischemia, circulatory dynamics, CO2 response and EEG findings after vascular occlusion of 6 hours. In all animals where rCBF was found to fall to less than 50% due to vascular occlusion, hemorrhagic infarction was found. The hemodynamics of those animals presenting hemorrhagic infarction was such that reflow resulted in a transient increase in rCBF followed by decrease within a short period. After a few hours, rCBF values had fallen to pre-occlusion levels. During the 6 hours occlusion, electrical activity became almost flat, and recovery following reflow was not seen. The CO2 response was found to be disturbed immediately following vascular occlusion and also did not recover following reflow. In contrast, among the animals in which hemorrhagic foci were not found, reflow resulted in recovery of rCBF to pre-occlusion levels within a short period. Electrical activity of the brain and CO2 response were found to be maintained throughout the period of occlusion and thereafter in these animals.

Animals↗
PubMed1983

[Administration of mannitol for severe superior sagittal sinus thrombosis].

A cured case of superior sagittal sinus thrombosis is reported. The patient, a 26-year-old man, also displayed severe complications such as hemorrhagic infarction and status epilepticus. Although his prognosis was considered to be extremely poor, conservative treatment, with mannitol, steroid, anticonvulsants, etc. was effective, and he was discharged without any neurological deficit. This report discusses the clinical course, CT findings, angiographical findings and regional cerebral blood flow (rCBF). At first, CT showed no abnormal findings, but hemorrhagic infarction was detected on the 3rd day after the onset. Follow-up CT showed subcortical low density area, hemorrhagic infarction with perifocal brain edema, midline shift etc; the focus of hemorrhagic infarction was almost absorbed 2.5 months after the onset. Cerebral angiogram showed not only the obstruction of the superior sagittal sinus but also that of cortical veins of cerebral convexity at first. Follow-up angiogram showed the development of collateral circulations such as deep cerebral, ophthalmic and emissary veins. On CBF study, low rCBF at the bilateral parasagittal region was observed, but marked increase of rCBF was measured in the parasagittal region, especially at the site of hemorrhagic infarction after the administration of 20% mannitol. We, therefore, consider mannitol as an effective agent for the treatment of cerebral sino-venous thrombosis.

Adult↗
PubMed1983

[Sequential changes of experimental cerebral infarction--CT and histological studies].

Using the canine thalamic infarction model, it was found that hemorrhagic infarction can be produced at a high frequency following recirculation after 6 hours of vascular occlusion. In the current study, sequential changes of histological findings and CT findings in the infarctic foci were investigated. Low absorption areas in the CT scans were apparent already by the 2 hours of recirculation. Thereafter, the boundary with the periphery became more distinct and was visible through the 6th week. Contrast enhancement could be seen 2 hours after recirculation and between 7 and 14 days thereafter. In histological study, leakage of red blood cells from the capillaries and small venules in the focus could be seen 2 hours after recirculation. This finding is thought to indicate that the mechanism of contrast enhancement is extravasation during this period. Macrophages began to infiltrate the focus from the surrounding tissue between the 2nd and 5th day. Between the 7th and 14th day, destruction of nerve cells and capillaries was seen, together with the formation of small cavities, but many small vessels from the peripheral tissue heading toward the focus were regenerated. It is thought likely that the contrast enhancement seen during this period was due to leakage of the contrast medium from these newly regenerated vessels. From around the 3rd week, destruction of the regenerated vessels from the periphery of the focus began and cavity formation progressed. By the 6th week, only a small amount of fibrous neural material remained and the cavity was well-formed.

Animals↗
PubMed1982

Uptake of hexavalent chromium by bovine erythrocytes and its interaction with cytoplasmic components; the role of glutathione.

Hexavalent chromium (Cr(VI)) anion gradually penetrated into bovine erythrocytes and bound with cytoplasmic components. Its penetration was strongly inhibited by the NH2-reactive agent, 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid (SITS) and the SH-reactive agent, N-ethylmaleimide (NEM). Gel filtration showed that the intracellular component that bound to chromium was hemoglobin. The binding affinity of Cr(VI) to hemoglobin in the absence of glutathione in vitro was found to be much less than in intact erythrocytes. However, in the presence of glutathione, the binding affinity of Cr(VI) to hemoglobin became much higher. This indicates that reduction of hemoglobin or Cr(VI) by glutathione is involved in the binding. Cr(VI) interacted only weakly with the membrane and did not cause hemolysis of bovine erythrocytes, unlike heavy metals such as Hg2+.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1982

Biochemical and cytological analyses of cystic fluid aspirated by percutaneous puncture under ultrasonic guidance in cystic diseases of the pancreas.

Ultrasonically guided percutaneous puncture of pancreatic cyst was performed on 4 patients with ultrasonically scanned cystic mass lesions in the left upper quadrant, and biochemical and cytological analyses of the aspirated cystic fluids were proved fairly diagnostic. In pseudocyst, the aspirated fluid revealed very high concentration of amylase, malignant cells being not recognized cytologically. In cystadenocarcinoma, the aspirated fluid revealed low concentrations of amylase and high concentrations of LDH and CEA, malignant cells being definitely recognized. This method is of great value for differential diagnosis of cystic diseases of the pancreas.

Adult↗