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Biomedical subjects

I Ihara

Publications and source records attributed to I Ihara.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Cerebral blood flow in subarachnoid hemorrhage: analysis in patients with poor outcomes].

Cerebral blood flow (CBF) of 6 patients with poor outcome after subarachnoid hemorrhage is analyzed. Neurological grades of these patients were grade III in 2 and grade IV in 4 patients, and subarachnoid hemorrhage on CT was diffuse and thick in all patients. Cerebral blood flow was continuously measured for 7 to 19 days by the thermal diffusion flow probe with a peltier stack which was left on the cerebral cortex at the surgery for ruptured aneurysm. Moreover, CBF studies by cold xenon CT and 133Xe inhalation methods were also performed in discussing cases. At the same time intracranial pressure was monitored. Cerebral angiography was carried out in all except for 2 patients who died due to severe cerebral vasospasm. The initial CBF value of all patients was 20 to 40 ml/100 g/min (mean value: 27 ml/100 g/min), and these were significantly low compared to normal value (50 ml/100 g/min). Moreover, these CBF was substantially decreased several days after surgery in all patients, and it was marked in 3 patients who died. From these results it was clear that the degree of vasospasm is important to determine the prognosis. One of 3 patients who died had ruptured left posterior cerebral artery aneurysm with occlusion of bilateral internal carotid arteries. In this case further decrease of CBF due to vasospasm was observed in addition to low initial CBF resulting diffuse low flow in both hemispheres although extracranial to intracranial bypass was performed. On the other hand, it was also shown that the intracranial pressure was an important factor to influence the outcomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[Intraoperative liquid embolization of an arteriovenous malformation in the basal ganglia and thalamic region].

Total three patients with arteriovenous malformation (AVM) in basal ganglia or thalamic region were treated by intraoperative liquid embolizations. These procedures were decided because of repeated hemorrhagic episodes. In the case with AVM in the head of the caudate nucleus which was fed by several anterior perforating arteries originated from anterior cerebral artery (A1 portion) and middle cerebral artery (M1 portion), frontotemporal craniotomy was performed. After the microsurgical dissection of these feeders, one of the feeders lenticulostriate artery, was cannulated with a small-caliber polyethylene catheter, 0.6 mm in outer diameter and 0.3 mm in inner diameter. A small amount of isobutyl 2-cyanoacrylate (IBCA) was injected through the catheter. Same procedure was carried out one month later. Postoperative angiograms revealed about 90% loss of AVM. In two cases with AVM which involved almost entire thalamus, subtemporal craniotomy was done. Feeding vessels which originated from posterior communicating artery and posterior cerebral artery (PCA) were carefully dissected under the operative microscope and one of them was prepared for cannulation with small catheter. When the small amount of IBCA was injected, proximal PCA and internal carotid artery were temporarily occluded. In both cases intraoperative embolization was carried out twice. Postoperative angiograms revealed that the size of AVM was decreased to 20% in one and 40% in the other. Although temporary postoperative deterioration of neurological deficits such as hemiparesis and visual disturbance was slightly noted in all cases, no hemorrhagic episode was experienced for 6 months, 1.5 and 2 years in each after embolization.

Adult↗
PubMed1986

Traumatic stenosis of the internal carotid artery in children.

Two cases of stenosis of the internal carotid artery after blunt craniocervical trauma in children are described. Their neurological symptoms developed a few hours after the injury. A superficial temporal artery-middle cerebral artery anastomosis was performed in one, and the other was conservatively treated because of the spontaneous resolution of the stenosis. The pathophysiology and treatment of this clinical entity, especially in children, are discussed.

Accidents, Home↗
PubMed1986

Study of the posterior circulation in moyamoya disease. Part 2: Visual disturbances and surgical treatment.

The involvement of the posterior circulation in moyamoya disease was studied in 178 patients. Forty-three had several types of disturbance such as visual field defect, decreased visual acuity, episodes of blindness, and scintillating scotomata. Most of these symptoms were attributed to occlusive lesions in the posterior circulation. Visual disturbances were seen more often in patients with a juvenile onset than in cases of adult onset. Superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis and encephalomyosynangiosis (EMS) improved the cerebral perfusion both in the anterior and posterior circulation by redistribution of blood. In most cases, the visual symptoms subsided or were stabilized after STA-MCA anastomosis and EMS. These surgical procedures did not, however, lead to direct revascularization in cases of ischemia in the visual cortex. In five patients with impending blindness, transplantation of the omentum to the occipital lobe led to improved vision.

Adolescent↗
PubMed1986

[The effect of artificial hypotension on postischemic cerebral edema in the reperfusion of middle cerebral arterial occlusion in cats--experimental study].

The effect of hypotension on postischemic cerebral edema was studied by the occlusion-reperfusion model of the middle cerebral artery (MCA) of a cat. The middle cerebral artery was transorbitally occluded for 3 hrs and reperfused for 3 hrs. We chose cats whose CBF decreased lower than 10 ml/100 g/min by the MCA occlusion. We studied 10 cats as a control group and 6 cats as the hypotension group. The mean arterial blood pressure was lowered artificially about 50 mmHg from the previous value using ATP and dipyridamole just before and during the reperfusion. The CBF was measured by the hydrogen clearance method and extradural pressure was recorded. The water content of cerebral hemisphere was measured by the drying-weighing method after sacrifice. In the control group the preocclusive value of CBF was 65.9 +/- 20.6 ml/100g/min and the value just after reperfusion was 35.0 +/- 21.5 ml. The value 3 hours after reperfusion was 8.2 +/- 11.0 ml. In the hypotension group, these values were 53.9 +/- 14.0 ml, 40.6 +/- 19.6 ml and 18.1 +/- 12.2 ml respectively. The ICP increased from 9.1 +/- 8.6 to 90.0 +/- 22.6 mmHg in the control group and in the hypotension group from 4.5 +/- 6.5 to 37.7 +/- 10.1 mmHg. The water content of the affected hemisphere was 79.7 +/- 0.5% in the control group and 79.1 +/- 0.5% in the hypotension group. The hypotension didn't change the CBF just after reperfusion and also maintained it more than the control until 3 hrs after the reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1986

[The effect of low dose dopamine on CBF in patients with subarachnoid hemorrhage].

Cerebral blood flow was measured in 10 patients with subarachnoid hemorrhage using the 133Xe inhalation methods. Regional cerebral blood flow (r-CBF) values were calculated with initial slope index, their values were compared with the blood flow response to the administration of low dose dopamine (DA). CBF values of just after and continuous administration of DA were compared with control values. The measurement of r-CBF was performed immediately after the infusion of 5 micrograms/kg/min DA for 30 min. The focal ischemic lesions decreased, bi-hemispheric mean CBF value (7 cases without A-Com patients) increased by 10.3% significantly (paired T test), affected hemispheric mean CBF value increased by 8.7% significantly and non-affected hemispheric mean CBF value increased by 16.6% significantly. The PaCO2 value didn't change but the mean systemic blood pressure increased by 5.1% significantly. The CBF values of continuous administration of DA for 10 days to 2 weeks were measured. The CBF values increased during the administration of DA. The mean CBF values increased without the steal phenomenon and the mean arterial blood pressure increased slightly after the administration of DA. These phenomena were observed more significantly in non affected side than affected side. We suggest that the administration of DA increase the CBF values in patients with subarachnoid hemorrhage due to the stimulation of DA receptor.

Adult↗
PubMed1984

A group of bactericidal factors conserved by vertebrates for more than 300 million years.

A complement-dependent bactericidal factor (RaRF) specific for the Ra chemotype strains of Salmonella and for the Ra-like strains of other enterobacteria has been found in sera of mice. We show here that the anti-Ra bactericidal factors are present in sera of all species, so far tested, of mammals, birds, reptiles, amphibians, and bony and cartilaginous fish. Certain properties, such as binding specificity, requirement of divalent cations for binding, and sensitivities to heat and reducing agents, of the factor in the representative animals were the same as or similar to those of the mouse RaRF. These results indicate that these factors have been conserved by vertebrates for more than 300 million years as a result of the necessity for the resistance to rough mutants of Gram-negative bacteria.

Amphibians↗
PubMed1982

A new complement-dependent bactericidal factor found in nonimmune mouse sera: specific binding to polysaccharide of Ra chemotype Salmonella.

It has been shown that nonimmune mouse sera contain a complement-dependent bactericidal factor that reacts specifically with Ra chemotype Salmonella. In this study we investigate a specific determinant to which this factor binds. This factor bound to Ra chemotype lipopolysaccharide (LPS) but not to S or Re chemotype LPS. The binding was markedly inhibited by N-acetyl-D-glucosamine (GlcNAc), which was the nonreducing terminal of the Ra polysaccharide chain and by certain monosaccharides structurally relating to L-glycero-D-mannoheptose, a terminal component of a side branch of Ra polysaccharide. The factor bound to the Ra bacteria could be eluted with a medium containing GlcNAc. These results indicate that the specific determinant is the polysaccharide region of LPS characteristic of Ra chemotype Salmonella. Ca2+ but not Mg2+ was required for the specific binding of the factor to cells of Ra bacteria. A molecule composed of a polypeptide of 28,000 m.w. was found in the active fraction obtained by the monosaccharide elution. However, no polypeptides corresponding to light and heavy chains of mouse immunoglobins were detected from the active fraction.

Acetylglucosamine↗
PubMed1982

Properties of a new complement-dependent bactericidal factor specific for Ra chemotype salmonella in sera of conventional and germ-free mice.

A complement-dependent bactericidal factor, Ra-reactive factor, that acts specifically on Ra chemotype strains of Salmonella was found in sera of eighteen strains of nonimmune mice, including a thymusless strain. The specificity of binding of this factor to the cells of Ra chemotype bacteria was evidenced by absorption studies. The factor was inactivated by treatment with 0.02 M 2-mercaptoethanol or heating for 30 min at 55 degrees C. This factor was present in mice reared by feeding with a chemically defined, antigen-free diet under germ-free conditions. Fetal and newborn mice from a conventional or germ-free mother had the factor, although the titer was lower than the adults'. The titer in the newborn mice reached adult level 1 wk after birth. The titer in the adult mice did not increase markedly after immunization with heat-killed bacteria or administration of Freund's complete adjuvant and turpentine. These results indicate that this factor is actively produced by mice that have never been stimulated with exogenous Ra antigen.

Animals↗
PubMed1981

Titration of bactericidal activity against smooth and rough strains of Salmonella which are resistant in isotonic medium.

Bactericidal factors in antisera against various chemotype strains of Salmonella were assayed by means of the spot method. Certain smooth and rough strains were resistant to the killing effect of immune mouse sera when the activity was assayed in an isotonic salt medium and guinea pig complement was used. However, the sensitivity was found to be increased in various degrees by assaying it in a medium containing hypotonic concentrations of NaCl or tris(hydroxymethyl)-aminomethane-HCl (Tris-HCl). Keeping the resistant bacteria in hypotonic solutions before or after treatment with complement increased the titer of antiserum, indicating that the hypotonic solution increases the sensitivity of bacterial cells to the antiserum and/or complement. The optimal salt concentration for the assay of serum-sensitive and -resistant smooth strains was 0.02 M NaCl. With Ra through Rd chemotype strains, 0.1 M NaCl before complement treatment and 0.05 M NaCl after the treatment was the best. Isotonic medium was necessary for the titration of the Re chemotype strain. Specificity of the killing effect which was assayed by the hypotonic spot method was shown by adsorption studies on the immune sera. Use of C4-deficient guinea pig complement resulted in low titers against certain strains of bacteria and high titers were restored by the addition of the C4 component of complement. These results indicate that serologically specific bactericidal factors including antibody can be assayed by the spot method using hypotonic NaCl or Tris-HCl.

Antibodies, Bacterial↗
PubMed1981

[Effect of hydrogenated ergot alkaloids on cerebral metabolism of the patients with neurological deficits after subarachnoid hemorrhage (author's transl)].

Cerebral blood flow and metabolism were measured in 9 patients with neurological deficits after subarachnoid hemorrhage using the 133Xe intra carotid injection methods. Regional cerebral blood flow (r-CBF) values were calculated with initial slope method (2 minutes flow index), their values were compared with the blood flow response to arterial PCO2 and to administration of hydrogenated ergot alkaloids (HEA). In case of repeated examination after short interval CBF values were corrected using the rate of reproducibility. The content of oxygen, glucose, lactate, and pyruvate in the arterial and the internal jugular blood were measured , and CMRO2, CMR glucose, CMR lactate, values were calculated: 1st step: The measurement of r-CBF was performed immediately after the infusion of 1.5 mg HEA for 15 minutes. The focal ischemic lesions decreased, mean CBF value increased by 8% significantly, arterio-venous difference of oxygen value increased by 20% significantly and CMRO2 value increased by 26% significantly after HEA administration. 2nd step: 1.8 mg HEA was infused for one week. EEG findings were improved after administration of HEA. The pressure and the lactate levels of cerebrospinal fluid decreased, but the effect of HEA must be carefully distinguished from natural recovery. Administration of HEA increased the CMRO2 values and consequently increased the mean CBF values.

Adult↗