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Biomedical subjects

O Sasaki

Publications and source records attributed to O Sasaki.

At least 19 recordsLinked to original sources
PubMed1992

Dissecting aneurysm of the posterior cerebral artery treated with proximal ligation.

A rare case of a dissecting aneurysm of the P3 segment of the right posterior cerebral artery is presented that seems to have occurred in association with mild head injury. The patient was treated surgically because of repeated intramural hemorrhage and enlargement of the aneurysm. Proximal ligation produced thrombosis of the aneurysm without resulting in infarction in the region of the posterior cerebral artery. The mechanisms of the dissection, diagnosis, and treatment are briefly discussed.

Adult↗
PubMed1992

Enhancement of the protective effect of inactivated influenza virus vaccine by cytokines.

The authors examined whether or not cytokines in conjunction with inactivated influenza virus vaccine enhance protection from influenza virus infection in mice. Mice were infected with influenza virus A/PR/8/34 (PR/8) at 10 LD50 by nebulizer after intranasal administration of the cytokine and the vaccine. The survival rate of the group which received both the vaccine and mouse recombinant interferon-beta (MuIFN-beta; 1 x 10(4) IU/mouse) or mouse recombinant interferon-gamma (MuIFN-gamma; 1 x 10(4) IU/mouse) was significantly higher than that of the control group given the vaccine alone. These results show that MuIFN-beta and MuIFN-gamma have an adjuvant effect on this vaccination. In contrast, human recombinant interleukin-2 (HuIL-2) and human recombinant tumour necrosis factor (HuTNF) did not have an adjuvant effect. In order to examine the mechanism of the enhancing effect of MuIFN-gamma on this vaccination, we determined the specific IgA and IgG antibodies present in bronchoalveolar lavage fluid (BALF) and serum, and haemagglutination inhibition (HI) antibody in serum. In the early stage of infection, the titres of IgA and IgG antibodies in the combined group receiving the vaccine with MuIFN-gamma showed a tendency to be higher than those in the group given the vaccine alone. In the late stage of infection, the titre of HI antibody in the group given the vaccine with MuIFN-gamma was significantly lower than that in the group given vaccine alone. It can be concluded from these results that a part of the adjuvant effect of MuIFN-gamma on this vaccination was due to an increase in production of antibodies which neutralized the virus in the lesion.

Animals↗
PubMed1992

Intra-tumor DNA ploidy distribution pattern and its relation to histologic type in gastric carcinoma.

The pattern of intra-tumor DNA ploidy distribution was analyzed in stepwise sections in 64 cases of surgically resected gastric carcinoma. Five varying patterns were identified: Type A comprised only diploidy in all stepwise sections, Type B comprised only aneuploidy with the same DNA Index(DI), Type C comprised diploidy in the great majority of sections with aneuploidy in some parts, Type D comprised aneuploidy in the great majority of sections with diploidy in some parts and Type E comprised only aneuploidy, but with varying DI. These 5 patterns could be grouped into 2 categories; predominantly diploid (Types A and C) and predominantly aneuploid (Types B, D and E). The former category included 34 cases (12 differentiated carcinomas) while the latter included 30 cases (22 differentiated carcinomas). Thus, a statistically significant correlation was detected between the histologic type and the intra-tumor DNA ploidy distribution pattern; in the majority of cases, differentiated carcinoma exhibited predominantly aneuploidy, while undifferentiated carcinoma exhibited predominantly diploidy (p less than 0.01). This tendency was the same for all depths of invasion, except for submucosal carcinomas which exhibited predominantly diploidy.

Adenocarcinoma↗
PubMed1992

Changes in cardiovascular mass, left ventricular pumping ability and aortic distensibility after calcium antagonists in Wistar-Kyoto and spontaneously hypertensive rats.

OBJECTIVES: To determine the effects of different dihydropyridine calcium antagonists on cardiovascular mass and function in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). METHODS: The rats were treated daily for 3 weeks with nitrendipine (20 mg/kg), nifedipine (30 mg/kg), nisoldipine (6 mg/kg) or their vehicles. At the conclusion of that period left ventricular pumping ability and aortic distensibility were determined, and the aortic, cardiac and left and right ventricular masses. RESULTS: Each drug reduced arterial pressure in both rat strains; each decreased left ventricular mass in SHR but not in WKY rats. All three agents increased right ventricular mass in WKY rats; only nisoldipine did so in SHR. Each compound improved left ventricular pumping ability in WKY rats, maintaining function even when pressure was abruptly increased to pretreatment levels. In contrast, although all three calcium antagonists improved cardiac performance in SHR at the pharmacologically reduced pressures, pumping ability was not maintained when pressure was increased to pretreatment levels in nisoldipine-treated SHR. All three agents improved aortic distensibility in both strains, but only in SHR was reduced aortic mass demonstrated. CONCLUSIONS: These data not only continue to demonstrate a functional/structural dissociation associated with antihypertensive therapy, but also suggest subtle functional and structural effects that differ even within the same class of calcium antagonists.

Animals↗
PubMed1992

PTA of supra-aortic arteries with temporary balloon occlusion to avoid distal embolism.

Percutaneous transluminal angioplasty (PTA) was carried out in eight patients with cervical arterial stenosis; six in the subclavian and brachiocephalic arteries (5 with subclavian steal syndrome), one in the common carotid artery, and one in both the brachiocephalic and common carotid arteries (with subclavian steal syndrome). The PTA balloon catheters were introduced via the femoral artery in seven and brachial artery in one. To prevent distal embolization through the vertebral and internal carotid arteries, the blood flow in these vessels was temporarily occluded with a balloon catheter. The dilation of the stenotic areas was generally satisfactory. Antegrade blood flow was promptly obtained in the vertebral artery even in patients with subclavian steal syndrome. In all patients, the clinical symptoms improved. Two patients underwent repeat PTA because of restenosis.

Adult↗
PubMed1992

[Detection of the deletion of interferon-alpha and beta genes in lymphoblastoid cells by PCR].

The HuIFN-alpha and beta genes were examined by the PCR method in the 11 human lymphoblastoid cell lines. The results showed that the homozygous deletion of HuIFN-alpha and beta genes was detected in 5 of 11 cell lines and in 5 of 11 cell lines, respectively. The deletions of both the HuIFN-alpha and beta genes were observed in 4 of 11 cell lines. One T cell leukemia cell line deleted only HuIFN-alpha gene, while the other T cell leukemia line deleted only HuIFN-beta gene. This suggests that the deletions of HuIFN-alpha and beta genes may be related the development of leukemia or lymphoma.

Burkitt Lymphoma↗
PubMed1991

Serial angiography in a spontaneous dissecting anterior cerebral artery aneurysm.

Intracranial dissecting aneurysms are uncommon, and little is known concerning the natural history of these lesions. In this paper we present a rare case of dissecting aneurysm of the anterior cerebral artery in which a true diagnostic sign of "double lumen" was demonstrated. Sequential changes in angiographic features shown on serial angiographic studies are described, and diagnosis is briefly discussed.

Aortic Dissection↗
PubMed1991

A study of the effects of delapril, a new angiotensin converting enzyme inhibitor, on the diurnal variation of arterial pressure in patients with essential hypertension using indirect and direct arterial pressure monitoring methods.

In order to investigate the effect of delapril, a new angiotensin converting enzyme inhibitor, on the diurnal variation of arterial pressure in patients with essential hypertension, this study examined 24 h arterial pressure using an indirect or a direct monitoring system. When the effect of twice-a-day administration of delapril at daily doses of 30 to 90 mg was examined using the indirect monitoring system in 12 outpatients, delapril decreased systolic and diastolic arterial pressures significantly only at limited points during the day. However, each of the averaged 24 h daytime and nighttime arterial pressures showed significant reductions. The 24 h intraarterial pressure monitoring demonstrated that delapril decreased systolic and diastolic arterial pressure at most of the measurement points. The arterial pressure reductions during daytime and nighttime were not significantly different, that is, there was no excessive reduction in nighttime arterial pressure. Heart rate and its variability were virtually unaffected by the delapril treatment in either monitoring study. No adverse reactions were observed in the indirect or direct monitoring studies. Thus, it is concluded that twice-a-day administration of delapril at daily doses of 30 to 90 mg brings about a safe and stable antihypertensive effect, without affecting the diurnal variation of arterial pressure.

Administration, Oral↗
PubMed1991

Subarachnoid hemorrhage from a dissecting aneurysm of the middle cerebral artery. Case report.

A case of subarachnoid hemorrhage (SAH) from a dissecting aneurysm of the inferior limb of the middle cerebral artery is reported. The patient's clinical status and the initial and follow-up angiographic appearance of the aneurysm are presented. Diagnosis and treatment are briefly discussed. It is suggested that, if angiography demonstrates luminal narrowing or vascular occlusion in a patient with unexplained SAH, a dissecting aneurysm of the carotid system should be considered as a cause of the hemorrhage.

Adult↗
PubMed1991

A clinicopathological study of dissecting aneurysms of the intracranial vertebral artery.

Five autopsied cases of dissecting aneurysms of the intracranial vertebral artery are reported and the literature is reviewed to clarify the clinicopathological correlations. In an autopsy series of 110 patients with subarachnoid hemorrhage (SAH), the incidence of this entity was 4.5%, with all five cases progressing rapidly to death from massive SAH. Cases of intracranial vertebral dissection can be divided clearly into two groups based on the clinical and pathological features. In the first group, the dissection is confined to the vertebral artery and a massive SAH develops caused by the rupture of the arterial wall. The plane of dissection is mainly subadventitial. In the second group, brain-stem infarction develops resulting from luminal occlusion by intramural hematoma. The plane of dissection is mainly subintimal, with the dissection extending to the basilar artery. The condition in the second group affects patients at a younger age. If the lesion is localized within the vertebral artery and does not extend to the basilar artery, the disease seems not to be fatal. The clinical features of the vertebral dissection are largely determined by the plane and extension of dissection. Vertebral artery dissection is due to many causative factors including hypertension, congenital or degenerative changes in the arterial wall, and anatomical and pathological characteristics of the vertebral artery.

Adult↗
PubMed1990

Dissociation of changes in cardiovascular mass and performance with angiotensin-converting enzyme inhibitors in Wistar-Kyoto and spontaneously hypertensive rats.

The effects of angiotensin-converting enzyme inhibitors on cardiovascular mass and function were measured in three groups of 22 week old male Wistar-Kyoto normotensive and spontaneously hypertensive rats treated with CGS-16617, cilazapril or quinapril. Left ventricular performance was assessed by electromagnetic flow meter during rapid whole blood infusion before and after arterial pressure and increased abruptly with aortic snare; aortic distensibility also was assessed in vitro. The systemic hemodynamic effects of these three agents were similar, yet their structural effects varied. Although left ventricular and aortic masses diminished and right ventricular mass remained unchanged (with all three agents) in the spontaneously hypertensive rats, CGS-11617 and cilazapril also reduced left ventricular mass in the normotensive Wistar-Kyoto rats without changing aortic mass. All three agents improved aortic distensibility whether or not mass was decreased. Left ventricular structural changes were associated with variable changes in pumping ability. These data show that reduced mass associated with angiotensin-converting enzyme inhibitor treatment was not consistent in ventricles and aorta, that a dissociation exists between structural and functional changes and that reduction of cardiac mass alone does not relate to changes in chamber mass or in function. Thus, biologic and pharmacodynamic differences exist among angiotensin-converting enzyme inhibitors as well as between classes of antihypertensive agents.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1990

Production of monoclonal antibody to bovine leukemia virus glycoprotein gp51 by in vitro immunization.

The monoclonal antibody against glycoprotein gp51 of bovine leukemia virus (BLV) envelope antigen was produced by in vitro immunization. This monoclonal antibody reacted with viral antigen was observed at the 69 kilodalton (kDa) glycoprotein. However, this monoclonal antibody was not involved in neutralizing. It was shown that in comparison with in vivo immunization, in vitro immunization has some advantages, namely a short immunization period and a small antigen quantity.

Animals↗
PubMed1990

Long-term results in a case of meningioma treated by embolization alone--case report.

A 73-year-old female, unable to walk without a cane, was hospitalized for evaluation of left sensorimotor disturbance. Computed tomographic (CT) scans revealed a large parasagittal mass, which was markedly and homogeneously enhanced by contrast material. Bilateral external carotid angiograms showed that the middle meningeal arteries supplied the tumor. Both CT and angiographic findings suggested a right frontal parasagittal meningioma. Catheter embolization with Ivalon (polyvinyl alcohol foam) particles was carried out prior to the planned surgery for the purpose of decreasing intraoperative hemorrhage from the tumor. However, her clinical symptoms began to improve 9 days after the embolization procedure, and surgery was decided against because of her advanced age and symptomatic improvement. Ten months after embolization, she was able to walk unassisted and CT scans showed a 60% reduction of the pre-embolization tumor size. Four years after embolization, she remained nearly asymptomatic despite some regrowth of the tumor.

Aged↗
PubMed1990

Reconstruction for the vertebral artery stenosis at its origin--bypass surgery using a saphenous vein graft with external shunting.

Eight patients with vertebral artery (VA) stenosis at its origin were surgically treated by a new reconstructive technique. Two patients suffered vertebrobasilar transient ischemic attacks, and five had brainstem and/or cerebellar infarction. All patients had multiple stenotic lesions, including bilateral VA stenoses in one and unilateral VA stenosis plus contralateral VA occlusion in seven. They underwent a subclavian artery to VA bypass using a saphenous short vein graft with external shunting. Postoperatively, no patients had aggravated neurological symptoms, and angiography showed all bypasses to be patent. One had an episode of transient loss of consciousness 8 months postoperatively, but the others showed no episodes of ischemia during an average follow-up period of 2 years and 10 months. The results indicate that this procedure is safer and more useful than other surgical procedures.

Aged↗
PubMed1989

Clinical and physiologic significance of local tissue renin-angiotensin systems.

Increasing and compelling evidence continues to amass that favors the existence of local tissue renin-angiotensin systems. All renin-angiotensin system components have been demonstrated in kidney, brain, arteries, adrenals, and other organs. Favoring its clinical importance are direct demonstration of its components in tissues; dissociation between hemodynamic and structural effects of renin-angiotensin system inhibition; evidence for local modulating roles with other humoral, autocrine/paracrine, and growth factors; and the effects of renin-angiotensin system inhibitors in patients who are anephric or have low plasma renin activity. Evidence will be presented demonstrating the hemodynamic/structural dissociation of pharmacologic agents that reduce cardiac mass in spontaneously hypertensive rats with left ventricular hypertrophy. Although centrally active adrenolytic agents, angiotensin-converting enzyme inhibitors, and calcium antagonists all reduce cardiac mass, their structural and cardiac functional effects differ greatly. Even within the angiotensin-converting enzyme inhibitor group their effects vary: improving, impairing, or not changing the Frank-Starling relationships. It is postulated that there is great variability of cardiac intramyocytic penetration of the pharmacologic agents and of their local intracellular effects on mitogenesis. The implications for cardiac function and therapy are vast.

Animals↗