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H Iwanaga

Publications and source records attributed to H Iwanaga.

50 records · Page 3Linked to original sources
PubMed1989

[Chronic subdural hematoma occurring in patients with senile dementia: report of 4 cases].

Four cases are presented of male patients over 63 years of age. Preceding head injuries relating to chronic subdural hematoma (CSH) were noted in 2 patients. Suspected clinical signs of CSH were disturbance of consciousness and mono- or hemiparesis. Surgery, a burr-hole technique for external drainage, was performed in 2 patients, and nonsurgical treatment by intravenous administration of glycerol was carried out in the remaining 2 patients. After the treatment, 3 patients returned to the previous demented state, and one who had been treated nonsurgically died of pneumonia. Disappearance or marked reduction of the hematoma was demonstrated by follow-up CT scans in all patients. The signs induced by CSH in a patient with senile dementia may be misunderstood as an aggravation of senile dementia. Nonsurgical treatment with osmotic perfusions for CSH may be considered as a treatment of first choice in a patient with advanced senile dementia, unless he shows advanced mass effect of the hematoma on CT.

Aged↗
PubMed1987

[An autopsy case of multicentric glioma of multiple histopathology].

An autopsy case is described of an 66-year-old man with multicentric glioma of multiple histopathology, i.e. protoplasmic astrocytoma and glioblastoma. Enhanced CT scan revealed three separate lesions in the right cerebral hemisphere, pons, and cerebellar vermis. Initial diagnosis by CT included metastatic and primary brain tumor, multiple abscess, fungal infection, parasites, tuberculoma, and so on. Biopsy of the right frontal mass revealed astrocytoma grade-2. An autopsy revealed gelatinous, clear marginal mass in the right frontal, parietooccipital and cerebellar vermis; an opaque marginal mass with necrosis in dorsal pons was found. At microscopic examination, the right frontal tumor exhibited continuity with both the paraventricular and the right parietooccipital tumor. The right cerebral hemisphere and cerebellar vermis tumors showed protoplasmic astrocytoma; the dorsal pons tumor showed glioblastoma. CSF examination revealed no tumor cells. Tumor invasion of the internal capsule and the meninges was also not found. Accordingly, we diagnosed as multicentric astrocytoma of multiple histopathology. Only 11 case reports of multicentric glioma were recorded in Japan; only one of which was of multiple histopathology. Worldwide, only 7 case reports of multicentric glioma of multiple histopathology were recorded; this is the first case of protoplasmic astrocytoma and glioblastoma. Seen in terms of pathogenesis of multicentric glioma, this case is thought to be very interesting.

Astrocytoma↗
PubMed1986

Effects of several antibiotics on the neuromuscular junction: Part II.

The effects of various kinds of antibiotics including tetracycline (TC), chloramphenicol (CP), sodium cephalothin (CET), sodium cefazolin (CEZ), colistin sulfate (CL), colistin sodium methanesulfonate (CL-M), bacitracin (BC), gramicidin HCl (GR), rifampicin sulfate (RFP) and lincomycin (LCM), on the neuromuscular junction (NMJ) were studied by in vitro and in vivo experiments. In in vitro experiments, CL and LCM exhibited a blocking effect on the NMJ in rat phrenic nerve diaphragm preparations, and GR caused a marked increase in muscle contraction. This effect was not affected by administration of eserine or CaCl2. In in vitro experiments with frog sciatica nerve and musculus sartorius preparations, CL and GR induced the appearance of endplate potentials, suggesting blockade of the NMJ. No blocking effect of other antibiotics was observed. In in vitro experiments with the preparations from Rana catesbiana frogs, TC and LCM induced a decrease in the frequency of miniature endplate potentials. In in vivo experiments with rabbit musculus tibialis anterior preparations, CL, TC and LCM exerted a blocking effect soon after administration, but GR and RFP had a late blocking effect. CL, GR, BC and RFP were found not to compete with eserine or CaCl2 in terms of the blocking effect on the NMJ. From the fact that TC did not compete with eserine but did compete with CaCl2 and with KCl as blockers at the NMJ, this blocking effect of TC seems to be due to inhibition of release of acetylcholine (ACh). The fact that LCM competes with eserine indicates that this antibiotic has the same type of action as curare on ACh receptors of the NMJ.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1986

Effects of aminoglycoside antibiotics on the neuromuscular junction: Part I.

The effects of aminoglycoside antibiotics (AGA) including streptomycin (SM), kanamycin (KM), gentamicin (GM), dibekacin (DKB), amikacin (AMK) and sisomycin (SISO), on the neuromuscular junction were studied by in vivo and in vitro experiments. In in vitro experiments, no effect of AGA on rat phrenic nerve diaphragm preparations was observed, but the use of the antibiotics at a high concentration exerted a slight blocking effect on the neuromuscular junction. The blocking effect of SISO and DKB on the neuromuscular junction was marked. These antibiotics were definitely found to compete with eserine in terms of the blocking effect on the neuromuscular junction, but did not compete with calcium chloride. In in vitro experiments with frog sciatic nerve and musculus sartorius preparations, DKB and SISO exerted a blocking effect on the NMJ, inducing the disappearance of action potentials and the appearance of endplate potentials (EPPs). In in vitro experiments with the preparations from Rana catesbiana frogs, SM, GM, DKB and SISO exhibited an inhibiting effect on the release of acetylcholine (ACh), a chemical neurotransmitter in neuromuscular junction, resulting in a decrease in the frequency of miniature endplate potentials (mEPPS). In in vivo experiments with rabbit sciatic tibialis anterior muscle preparations, SM, GM, DKB and SISO exerted a blocking effect on the neuromuscular junction. From the facts that the effect was augmented by the use of magnesium chloride combined with these antibiotics and that the antibiotics competed with calcium chloride and potassium chloride in terms of the blocking effect on the neuromuscular junction, the effects seemed to be due to the inhibition of ACh release.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1980

[The association of cerebral aneurysm with malignant brain tumor--report of a case (author's transl)].

A rare case was reported in which a brain tumor was associated with a cerebral aneurysm. A 59-year-old woman was admitted with right spastic hemiparesis and motor aphasia. She was in somnolence and complained of headache. She had two attacks of loss of consciousness about 12 years previously. Since then she had right spastic hemiparesis and motor aphasia as sequelae. Preoperative CT scan and carotid angiograms showed a malignant brain tumor in the left temporal region and an anterior communicating artery aneurysm. Operation was performed in one stage. At first the neck of the aneurysm was clipped by right sphenoidal approach and the tumor was partialy removed by left temporal approach. The histological diagnosis was glioblastoma multiforme. The cerebral aneurysm associated with brain tumor should be treated as soon as possible. The operative result in our case was good.

Brain Neoplasms↗
PubMedDate not supplied

Effect of nicardipine and diltiazem on internal carotid artery blood flow velocity and local cerebral blood flow during cerebral aneurysm surgery for subarachnoid hemorrhage.

STUDY OBJECTIVE: To determine the hemodynamic effects of a bolus injection of nicardipine 1 mg or diltiazem 5 mg on local cerebral blood flow (LCBF) and internal carotid blood flow velocity (ICBFV) with isoflurane anesthesia. DESIGN: Randomized study. SETTING: Inpatient neurosurgery and anesthesia clinic at a city hospital. PATIENTS: 26 patients with subarachnoid hemorrhage who were scheduled for cerebral aneurysm clipping. INTERVENTIONS: A bolus injection of either nicardipine or diltiazem was administered to patients whose systolic blood pressure increased to over 150 mmHg after opening of the dura. MEASUREMENTS AND MAIN RESULTS: After the bolus injection, both drugs rapidly decreased arterial blood pressure. Nicardipine increased LCBF [before injection, 42.1 +/- 12.3 ml/100 g/min; after injection, 47 +/- 10.7 ml/100g/min; (p < 0.05 vs control); after recovery, 42.4 +/- 11.1 cm/sec], but diltiazem did not change LCBF. Nicardipine 1 mg moderately increased ICBFV [before injection, 34.2 +/- 9.3 cm/sec; after injection, 40.6 +/- 8.7 cm/sec (p < 0.01 vs. control); after recovery, 34.1 +/- 8.9 cm/sec], but diltiazem did not change ICBFV. In addition, venous partial oxygen pressure and saturation of the internal jugular did not change throughout the study. There was a close correlation between presurgical neurologic status and LCBF (rs = -0.743; p < 0.01) and ICBFV (rs = -0.721; p < 0.01). CONCLUSIONS: Nicardipine increased LCBF and ICBFV, but diltiazem did not change either. These results suggest that both drugs are useful and safe for the treatment of intraoperative hypertension during cerebral aneurysm surgery.

Adult↗
PubMedDate not supplied

Choroid plexus papilloma containing melanin pigment.

The authors report a case of a choroid plexus papilloma in the fourth ventricle containing melanin pigment. The pigmented granules in this tumor were positive for Fontana-Masson, periodic acid-Schiff, acid fast and Sudan staining, suggesting that the pigment contained lipofuscin as well as melanin. The possibility that the melanin derived from lipofuscin by "melanization" through pseudoperoxydation is discussed.

Cerebral Ventricle Neoplasms↗
PubMedDate not supplied

Pressure distribution using tissue conditioners on simplified edentulous ridge models. Part 1: The influence of the height of the residual ridge.

This study was conducted to measure the changes of pressure distribution over time on the denture-bearing mucosal surface resulting from relining the intaglio surface of dentures with tissue conditioners. Pressure sensors of electrostatic capacitance variation were used to detect changes on three models of different residual mandibular ridge height. It is suggested that the shrinkage of tissue conditioners influences the dimensional accuracy of a dynamic impression technique.

Alveolar Bone Loss↗
PubMedDate not supplied

Pressure distribution using tissue conditioners on simplified edentulous ridge models. Part 2: The influence of the powder particle size and ethanol content.

The distribution of pressure changes over time at the denture periphery and the residual ridge crest were measured to evaluate the influence of powder particle size and ethanol content in liquid of tissue conditioners used for a dynamic impression technique. The study suggested that the shrinkage of tissue conditioners over time influenced the adaptation at the denture periphery when the components of tissue conditioners were varied for use as a dynamic impression material.

Dental Impression Materials↗