Search PubMed⌕ Search

Biomedical subjects

H Mihara

Publications and source records attributed to H Mihara.

At least 181 records · Page 10Linked to original sources
PubMed1979

Fluid pressure and fibrinolytic activity in implanted subcutaneous and intramuscular capsules.

Using the capsule implantation method, the relationship between the intracapsular fluid pressure (IFP) and fibrinolytic activity of the intracapsular fluid was examined in subcutaneous and intramuscular capsules. When IFP was positive, the sterility test was positive (indicating infection), the fibrinolytic activity was enhanced, and the response of IFP to volume change or hypertonic solutions was poor. On the other hand, when IFP was negative, the sterility test was negative, the fibrinolytic activity was weak, and the response of IFP to volume change or hypertonic solutions was good. Also, the more negative the IFP, the weaker was the fibrinolytic activity in the intracapsular fluid (r = 0.60, p less than 0.01). The ratio of the intracapsular fluid fibrinolytic activity to the plasma fibrinolytic activity showed a good correlation to the intracapsular fluid pressure (r = 0.68, p less than 0.01). When the fibrinolytic activity was activated by injection of streptokinase and human plasma, the IFP showed a tendency to increase. These results suggest that the fibrinolytic system plays some role in the maintenance of local fluid balance.

Animals↗
PubMed1978

Urokinase inactivation rate in the rabbit: effect of circulatory isolation of the liver, spleen and kidneys.

After injection of urokinase (UK) in normal rabbits and in rabbits with ligated liver, spleen and kidneys, the inactivation rate constant of UK was evaluated by using the disappearance rate of fibrinolytic activity from plasma. A peripheral intravenous injection of UK in normal rabbits induced significant but transient fibrinolytic activity, with ligated liver, spleen and kidneys, the fibrinolytic activity sustained for a long period, i.e. the inactivation rate constant of UK was 6 times smaller compared with normal rabbits. The implications of these results are discussed.

Animals↗
PubMed1977

In vitro and in vivo measurement of total antiplasmin activity.

Total antiplasmin was measured in vitro and in vivo. In the former case, rabbit plasma was mixed with various concentrations of Urokinase (UK) and the least concentration for appearance of fibrinolytic activity was estimated. This concentration was multiplied by the plasma volume of the rabbit to give the in vitro total antiplasmin. The mean value for 14 rabbits was 4,068.6 units. In order to estimate the total antiplasmin in vivo, UK solution was infused into rabbits. The infusion speed was multiplied by the time of the first appearance of fibrinolytic activity to give the total antiplasmin, although when the infusion speed was low, fibrinolytic activity did not appear during infusion. The mean in vivo total antiplasmin calculated for 6 cases where the infusion speed was high and fibrinolytic activity was observed, was 28,699.8 units, i.e. about 7 (range, 3-11) times the in vitro value.

Animals↗
PubMed1976

Is angiographic spasm real spasm?

Systematic morphological study of the cerebral arteries was made in six autopsy cases of ruptured aneurysms. The time course of the arterial luminal narrowing was observed by repeated angiograms, and segments of the narrowed arteries were studied histologically. Various histological changes were found consistent with the angiographic findings. We have devided these into three stages according to the duration of the disease. In the acute stage (less than one day) the contraction of the medial smooth muscle cells may be the main cause of the luminal narrowing. In the subacute stage, arteries showed a reduction in lumen size with medial thickening, marked corrugation of the internal elastic lamina, and thrombus formation attached to the endothelial surface. If vasoconstriction remained localized to the same segment for several days, the intimal or medial thickening and thrombus might produce the luminal narrowing consistent with the angiographic narrowing. In the chronic stage (more than two weeks), most cases showed dilatation of the arterial lumen on angiography. These arteries showed frank necrosis of the smooth muscle cells histologically. In a case which demonstrated progressive luminal narrowing on angiograms over 2 weeks, the arterial wall showed luminal narrowing with cellulofibrous thickening of the intima and organization of the thrombus. The presence of these structural changes in the narrowed arteries seen at angiography seems to be very important for proper understanding and treatment of vasospasm.

Acute Disease↗
PubMed1976

[Communicating hydrocephalus following the rupture of intracranial aneurysm (author's transl)].

It is well recognized that the communicating hydrocephalus following the rupture of intracranial aneurysms is one of the factors which cause the disturbance of consciousness in acute stage and the impairment of mental functions in chronic stage. In this report we analyzed the surgical experience with this complication and discussed the mechanisms which cause the ventricular dilatation. 1. The communicating hydrocephalus following the rupture of intracranial aneurysms is devided into the acute form and the chronic form. 2. Acute communicating hydrocephalus may develop with 24 hours after the onset and the incidence is about 10% (6 out of 66 cases). 3. Intraventicular pressure is high in acute communicating hydrocephalus and becomes normal in chronic stage. 4. The incidence of the chronic communicating hydrocephalus is about 10% (6 out of 66 cases). 5. There are two types of chronic communicating hydrocephalus. One develops from acute form and another develops gradually after onset. Among 6 chronic communicating hydrocephalus, 3 developed from acute form, 2 showed slowly progressive ventricular dilatation and 1 admitted with hydrocephalus at chronic stage resepctively. 6. The intraventricular pressure of the acute form is high and the chronic form shows high pressure in acute stage, intermittent high pressure wave lasting 20-30 minutes in subacute stage and normal pressure in chronic stage when the ventricle is dilated. 7. The mechanisms of ventricular dilatation in normal pressure hydrocephalus are discussed on the basis of the continuous monitoring of intraventricular pressure in cases with rupture of intracranial aneurysm. 8. Indication of shunting procedures whould be determined by combination of clinical pictures, ventriculocranial index, findings of cisternography and EEG. Our operative criteria are presented.

Acute Disease↗
PubMed1975

[Surgical experience of aged patients with ruptured intracranial aneurysms (author's transl)].

Outcome of 77 cases with ruptured intracranial aneurysms above 60 years of age was reported. 44 cases were treated conservatively and 33 cases surgically. 1. Among conservatively treated group, 10 cases died after initial hemorrhage and 14 cases after second hemorrhage. The mortality rate was 55%. 2. Among surgically treated group, 11 cases died and 4 cases had severe neurological deficits following the direct intracranial operation. The mortality and morbidity rate was 33% and 12% respectively. 3. These results indicate that the direct intracranial operation should be the first choice of treatment to the aged patients also. 4. Intracranial complications occured more frequently than the extracranial one during intra and postoperative course. Among them normal pressure hydrocephalus was the comonnest. 5. Occlusion of the main cerebral artery occured in 5 cases related to operative procedure. Outcome of 4 cases of them was poor. Microsurgical technique should be used in order to prevent these conditions which tend to occur in aged patients.

Adult↗