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H Iwasa

Publications and source records attributed to H Iwasa.

At least 91 records · Page 5Linked to original sources

[Downward migration of the optic system after transsphenoidal approach of a giant eosinophilic adenoma (author's transl)].

Headache and visual impairment resulting from downward migration of the optic system in an acromegalic patient, occurred after one year postoperatively. A 25-year-old woman with eosinophilic adenoma was operated on via transsphenoidal approach and irradiated (5,000 rads) following the operation. After the operation, bitemporal hemianopia was thoroughly improved and serum HGH level was also markedly decreased after radiation therapy. One year later, headache and visual impairment recurred. Pneumoencephalogram revealed that the infundibular and optic recessus of the third ventricle were elongated and descended into the sella turcica. The second operation was performed by subfrontal approach and the optic system was found to be migrated into the sella, which we assumed to be the cause for the recurrence of the headache and visual field defect. In order to prevent this type of complication, it would be recommended to fill up the dead space in the sella with bone or cartilage fragments in addition to muscle pieces, as was suggested by Guiot et al.

Adenoma, Acidophil↗

Electrophysiological properties of so-called inactivation response and their relationship to dendritic activity in hippocampal pyramidal cells of rabbits.

(1) The so-called inactivation response (IR), i.e. a prolonged (duration, 40-80 msec) and large (magnitude, more than 20 mV) depolarization of the cell membrane with superposed spike burst exhibiting a strong tendency of spike inactivation, was studied with an intracellular microelectrode in hippocampal pyramidal cells of rabbits, which were anesthetized with Nembutal and, in addition, curarized. (2) Evidence was presented that an all-or-nothing process was involved in the mechanism of production of the IR. (3) The threshold of the spontaneous IR was lower by more than 10 mV than that of the IR induced with depolarizing current injected into the cell body. From this, it was inferred that the IR originated at a site away from the cell body, possibly in the dendrites. (4) Two kinds of small fast spikes (magnitude, 10-20 mV) and spike-like potentials (magnitude, 8-22 mV; duration, 6-15 msec) were shown to exist. All of them were of high threshold and not related in magnitude to the membrane potential of the cell body. The dendrites were suggested as possible sites of their origin.

Animals↗

[Tentorial dural arteriovenous malformation--a case report (author's transl)].

UNLABELLED: A case of tentorial dural AVM was reported. A 52 years old man came to the Jichi Medical School hospital on July 29, 1974, with the chief complaints of intermittent left exophthalmos, diplopia and left blepharoptosis, which had been noted since March of 1974. He had episodes of severe headache attack since 3 years prior to the hospital visit. Angiography done at the out-patient department demonstrated the dural AVM with the nidus in the left tentorium. The nidus was fed by the left posterior middle meningeal artery, the dural branch of the left occipital artery, the left posterior cerebral artery, the left superior cerebellar artery and the dural branches of vertebral artery. It was drained to the vein of Labbé and the two cortical veins of the occipital lobe. He was appointing admission under the diagnosis of dural AVM, but he had an apopleptic attack three days before the appointed date, so was admitted in emergency. Neurological examination on admission: The patient was in drowsy state, papilledema on the both sides and right hemiparesis including the face were noted. The bruit was not audible. Left CAG revealed intracerebral hematoma in the left tempotal lobe, so that the removal of the intracerebral hematoma and the middle meningeal artery ligation were carried out after his general condition improved, on October 18, 1974. On October 30, 1974, the second operation was performed in an attempt of the radical excision of the AVM nidud. But, unfortunately, the patient fell into the shock state so that the operation had to be stopped at the stage of the ligation of the feeders running in the dura of the posterior fossa. The third operation was done on February 19, 1975. The AVM nidus was removed with the left transverse sinus and a part of tentorium. He was discharged on March 3, 1975, with only the right homonymous hemianopsia. Nine months after his discharge, there was no sign of recurrence of AVM. PATHOLOGICAL FINDINGS: The left transverse sinus was almost occupied with AVM tissue. The endothelium of arteries were hypertrophied and the internal elastic bnadles were partly defected. Veins showed also hspertrophy of the endothelium and the thrombus formation. The dural AVM of the posterior fossa is not a rare malady, especially in the recent years, probably due to the technical advances in the roentgenology, such as magnification techniques as well as selective arterial catheterization. The most common signs and symptoms of this disease picked up from the reports of 112 cases in the literature are: bruit 47%, headache 44%, papilledema 26% and SAH 24%. The extra cranial ligation of feeders were reportedly carried out on 39 cases, but only 9 cases (23%) were effective. Therefore, the radical excision of the nidus would be the most desirable method for the complete treatment of the dural AVM.

Cranial Fossa, Posterior↗

Ulcuscarcinoma.

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Adenocarcinoma↗