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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 559 records · Page 31Linked to original sources
PubMed1985

Moyamoya disease.

Explore the source record for details and available documents.

Arterial Occlusive Diseases↗
PubMed1985

Fibronectin and deposits of fibrinolytic components in glomerular capillary walls.

The distribution of fibronectin (FN) and the depositions of fibrinolytic components in human renal glomeruli with a variety of pathologic disorders were examined on biopsy specimens by immunofluorescence and immunoenzymatic methods. In a majority of the cases with thickening of capillary walls and/or with fibrin deposits in the capillary walls, staining for FN along the walls of the capillary loops (capillary pattern) was noted in addition to the staining in the mesangial area. In the capillary pattern with fibrin deposition, deposits of alpha 2-plasmin inhibitor and plasminogen, which are major components of the fibrinolytic system, were also seen along the capillary walls with a high frequency of occurrence. Plasminogen deposits, however, were found only in the glomeruli with deposits of alpha 2-plasmin inhibitor. There was no direct relationship between the degree of proteinuria and the appearance of the capillary pattern of FN or the deposition of the fibrinolytic components. These findings suggest that the appearance of FN in the walls of the capillary loops has some causal relationship with the local activation of blood coagulation factors which is frequently followed by activation of the fibrinolytic enzyme system.

Adult↗
PubMed1985

Arteriovenous malformation in the territory of the occluded middle cerebral artery with massive intraoperative brain swelling: case report.

We present an extremely rare case of an arteriovenous malformation (AVM) in the territory of the middle cerebral artery, the main trunk of which was occluded asymptomatically. Immediately after an uneventful excision of the entire AVM, massive brain swelling occurred unexpectedly and was treated successfully with high dose barbiturate therapy associated with other standard measures of controlling increased intracranial pressure. The underlying pathophysiological mechanisms leading to the massive intraoperative brain swelling in this case are discussed.

Adult↗
PubMed1985

Combined occipital transtentorial and infratentorial supracerebellar approach in the concorde position for the treatment of an arteriovenous malformation in the upper vermis: case report.

With a patient in the concorde position, lying prone with the head flexed and tilted laterally, higher than the heart, it is possible to use both the occipital transtentorial and infratentorial supracerebellar approaches without changing the patient's position. We report the successful treatment with this combined approach of an arteriovenous malformation in the upper vermis supplied by the superior cerebellar artery.

Arteries↗
PubMed1985

Unilateral subdural-peritoneal shunting for bilateral chronic subdural hematomas in infancy. Report of three cases.

The authors present the cases of three infants with bilateral chronic subdural hematomas (SDH's) (effusions). Communication between the hematoma cavities was confirmed by an injection of air or metrizamide into one of the cavities. In all three cases, both SDH's (effusions) were successfully treated by placement of a unilateral subdural-peritoneal shunt without any untoward consequences. It is stressed that the cavities of bilateral chronic SDH's (effusions) may communicate, and that in such cases unilateral subdural-peritoneal shunting is sufficient to eradicate the SDH's on both sides. In addition, subdural fluid, even with a high protein concentration, may be successfully eliminated by an internal shunt using a shunt tube with a large internal caliber and a low-pressure valve.

Female↗
PubMed1985

Acceleration of fibrinolysis by the N-terminal peptide of alpha 2-plasmin inhibitor.

When blood plasma containing the NH2-terminal 12-residue peptide (N-peptide) of alpha 2-plasmin inhibitor (alpha 2PI; alpha 2-antiplasmin) was clotted in the presence of calcium ions, the N-peptide and alpha 2PI were cross-linked to fibrin by activated coagulation factor XIII. The amount of N-peptide cross-linked to fibrin was proportional to the concentration of N-peptide present in plasma. On the other hand, the amount of alpha 2PI cross-linked to fibrin was decreased by the presence of N-peptide, and the decrease was in reverse relationship to the increase of cross-linking of N-peptide. Spontaneous fibrinolysis or fibrinolysis induced by tissue plasminogen activator was accelerated by the presence of N-peptide, and the acceleration was dependent on the concentrations of N-peptide and directly proportional to inhibition of alpha 2PI cross-linking exerted by N-peptide. The acceleration was more pronounced when the clot was compacted by platelet-mediated clot retraction or by a squeeze. Fibrinolysis of an alpha 2PI-deficient or a factor XIII-deficient plasma clot was not accelerated by N-peptide. These findings were substantiated in a purified system and support the previous proposal that alpha 2PI is cross-linked to fibrin at the glutamine residue that is next to the NH2-terminus of alpha 2PI, and this factor XIII-mediated cross-linking of alpha 2PI is significant in inhibition of physiologically occurring endogenous fibrinolysis.

Fibrin↗
PubMed1985

Longer survival and fewer metastases by levamisole and tegafur in 1, 2-dimethylhydrazine-induced murine colonic cancers.

The anticancer effects of levamisole, tegafur and their combination were experimentally compared in rats on the 1, 2-dimethylhydrazine (DMH)-induced colonic cancers. DMH at 20 mg/kg of body weight was injected subcutaneously to Donryu rats once a week for 24 weeks long. Nineteen weeks after the start of DMH administration, early colonic cancers were induced and, 28 weeks after, they developed into advanced cancers with distant metastases. From 19 weeks after the start of DMH injection, subcutaneous administration of levamisole at the dose of 2 mg/kg, oral administration of tegafur at 90 mg/kg and their combination were given to the rats daily for nine weeks. The animals were sacrificed 28 weeks after the start of DMH administration. Tegafur was effective, but levamisole with or without tegafur was not effective against early cancer. From 28 weeks after the start of DMH injection, levamisole, tegafur and their combination were administered to the rats daily for four weeks. All of the rats were necropsied when they died. The survival rate and mean survival days were significantly higher and longer in the levamisole groups than in the control rats (p less than 0.05). The incidence of distant metastases was also significantly lower in the levamisole groups than in the control group.

1,2-Dimethylhydrazine↗
PubMed1985

Communicating triventricular hydrocephalus and its treatment with a lumboperitoneal shunt.

With computed tomography, triventricular hydrocephalus shows enlargement of the 3rd and both lateral ventricles with a nearly normal size 4th ventricle. Triventricular hydrocephalus has been described as noncommunicating because of aqueductal stenosis or obstruction. The authors, however, have encountered three patients whose computed tomographic (CT) images were those of triventricular hydrocephalus despite a patent aqueduct. This condition may be suitably referred to as communicating triventricular hydrocephalus because in all cases metrizamide CT cisternography demonstrated the communication between the spinal subarachnoid space and both lateral ventricles. The authors discuss its treatment with a lumboperitoneal shunt.

Cerebral Ventricles↗
PubMed1985

[Transcatheter embolization therapy of esophageal varices and hypersplenism with liver cirrhosis].

Transcatheter variceal embolization (PTO, TIO) has been performed in 71 cases and splenic artery embolization (SAE) in 22 cases (15 PTO-SAE combination and 7 SAE alone). Results for varices of PTO combined with SAE were better than with PTO alone. Furthermore PTO combined with SAE was found to be reliable even for long term control of bleeding, the longest follow up being almost over 3 years during which time we have had no case of rebleeding. Improvement of Child's criteria was seen to be better in SAE cases (52.4%) than in splenectomized cases (12.5%) and PTO alone (17.4%). Hepaplastin test and level of cholinesterase were used to assess liver function, before and after treatment. It was found that SAE cases improved considerably, in contrast to the splenectomized and control cases which showed little or no improvement. Thus to increase durability for long term control of bleeding and general condition, PTO should be combined with SAE. Furthermore, it is suggested that this combined embolization therapy should be used for nonsurgical treatment of esophageal varices and hypersplenism with liver cirrhosis.

Embolization, Therapeutic↗
PubMed1984

[Changes of gastrin levels in autoimmune thyroid disorders. Part I: Thyroid functions and gastrin levels].

The relationship between thyroid disorders and gastric pathophysiology has been studied mainly from standpoints of gastric histology and gastric acid output capacity. Though anti-gastric antibody has been thought to play a part in this relationship, there have been no clear conclusions obtained about that. Since blood gastrin levels are easily measurable by radioimmunoassay today, the relationship between thyroid disorders and gastric pathophysiology has drawn attention again from a standpoint of gastrin levels. Seino et al. have reported about hypergastrinemia in hyperthyroidism, speculating that beta-adrenergic hyperresponsiveness of gastrin-producing cells could be the mechanism of hypergastrinemia. However, there are other reports which mentioned feedback mechanism between gastrin and gastric acid or interaction of gastrointestinal hormones as the main mechanism of hypergastrinemia. In this study, the problem of gastrin in Graves' disease and chronic thyroiditis were studied by measurement of fasting serum gastrin levels and gastric juice excretion in view of feedback mechanism between gastrin-producing cells and parietal cells which are the target cells of gastrin. Following results were obtained. Fasting serum gastrin levels in Graves' disease were 236.2 +/- 39.1 (mean +/- SE) pg/ml for 39 hyperthyroid patients and 126.3 +/- 23.9 pg/ml for 35 euthyroid patients. These levels were significantly higher than those of sex and age-matched control subjects with P less than 0.001 and P less than 0.05, respectively. Fasting serum gastrin levels in serial studies of 13 patients with Graves' disease were 222.3 +/- 56.7 pg/ml before treatment and 167.3 +/- 56.6 pg/ml at the time of euthyroid state after a mean observation period of 6.6 +/- 1.1 months. Fasting serum gastrin levels at the time of euthyroid state decreased significantly when compared with fasting serum gastrin levels before treatment (P less than 0.05). Fasting serum gastrin levels in chronic thyroiditis were 160.7 +/- 51.1 pg/ml for 24 hypothyroid patients and 96.4 +/- 24.7 pg/ml for 31 euthyroid patients. Each of these levels had no significant differences when compared with sex and age-matched control subjects. Fasting serum gastrin levels in serial studies of 10 patients with chronic thyroiditis were 81.1 +/- 18.0 pg/ml at the time of hypothyroid state and 91.5 +/- 15.2 pg/ml at the time of euthyroid state after a mean observation period of 7.1 +/- 2.1 months. Fasting serum gastrin levels before treatment had no significant differences when compared with fasting serum gastrin levels in euthyroid state.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

Urinary procoagulant behaves as tissue factor by promoting factor VIIa-catalyzed activation of factor X.

We purified the urinary procoagulant from frozen human urine by introducing phenyl-Sepharose hydrophobic chromatography. By this method, the apoprotein of the procoagulant and the lipid-like substance were separately recovered. Upon reassociation with the lipid-like substance or exogenous crude phospholipids, the apoprotein accelerated factor VIIa-catalyzed activation of factor X, probably by forming a stoichiometric complex with the catalytic enzyme. Thus the procoagulant was confirmed to be a tissue factor by its mode of participation in the blood coagulation mechanism.

Apoproteins↗