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Biomedical subjects

S Sakaki

Publications and source records attributed to S Sakaki.

At least 145 records · Page 8Linked to original sources
PubMed1988

Free radical reaction and biological defense mechanism in the pathogenesis of prolonged vasospasm in experimental subarachnoid hemorrhage.

The relationship between free radical reactions and the defense mechanisms against them was investigated in the pathogenesis of prolonged vasospasm following experimental subarachnoid hemorrhage (SAH) in dogs. The concentration of lipid peroxides in the cerebro spinal fluid (CSF) increased markedly up to the eighth day following SAH; the concentrations also rose in the arterial wall (p less than 0.01) and the gray matter of the temporal lobe where the subarachnoid blood clots were (p less than 0.01). On the other hand, the activity of superoxide dismutase (SOD) decreased significantly up to the eighth day after SAH (p less than 0.01), and there was a gradual increase of glutathione peroxidase (GSH-px) in the CSF. In the arterial wall, there was a slight decrease in the activity of SOD, a significant decrease in the activity of GSH-px (p less than 0.01), and also a significant decrease in the concentration of glutathione (p less than 0.01) up to the eighth day following SAH. In conclusion, lipid peroxidation with insufficient biological defense mechanisms against it in the arterial wall, concomitant with that in the CSF, might take part in the genesis of prolonged vasospasm following SAH.

Animals↗
PubMed1988

Assessment of warfarin therapy under full dose using indium-111 platelet scintigraphy in patients with intracardiac thrombi.

Twenty patients in whom intracardiac thrombi were detected by indium-111 platelet scintigraphy (the first platelet scintigraphy) were prospectively studied to examine the effect of warfarin therapy under full dose on the intracardiac thrombogenicity. Eleven patients (group I) who received 2-6 mg/day of warfarin and 9 patients (group II) who did not receive warfarin had the second platelet scintigraphies 14-71 days after the first platelet scintigraphies. In group I, 10 platelet scintigraphies became negative and one remained positive for intracardiac thrombi after administration of warfarin, while in group II 8 platelet scintigraphies remained positive and only one changed to negative. The incidence of negative image at the second platelet scintigraphy was significantly lower in group II than that in group I. In group I, the degree of accumulation of platelets onto the surface of the thrombus (%IE), showed significant reduction (0.69 +/- 0.48 to 0.11 +/- 0.21) after warfarin therapy, while in group II %IE at the second scintigraphy (1.07 +/- 1.03) were not significantly different from those at the first scintigraphy (1.13 +/- 0.79). These results indicated that warfarin therapy under full dose inhibited the deposition of platelets on the intracardiac thrombi and thrombogenicity in the patients with intracardiac thrombi which were detected by indium-111 platelet scintigraphy.

Adult↗
PubMed1988

[Malignant thymoma with intracranial metastases].

Malignant thymomas usually proliferate invasively and rarely metastasize to other organs. Since the metastases occur predominantly to the liver and kidneys, there have been only 16 cases with metastatic spreads of malignant thymomas to the central nervous system reported in the literature. A 59-year-old man was admitted with complaints of dizziness and vomiting. Three years and three months ago, he had been operated upon for mediastinal tumor, which was diagnosed as a predominantly lymphocytic type thymoma, and then followed by irradiation therapy of 3800 rads. The size of the tumor decreased markedly after the irradiation. Nine months after the operation, he complained again of dizziness and vomiting. Computed tomography scans showed a tumorous lesion in the right cerebellar hemisphere, which was thought to be a metastasis from the thymoma. He received radiotherapy of 4000 rads directed to the intracranial metastatic tumor, with the reduction of the tumor size and the relief of symptoms. On the present admission, he had cerebellar signs and symptoms. Neuroradiologically, there was a hypervascular tumor in the left cerebellar hemisphere and a hypovascular one in the right. At operation, a vascular and solid tumor with small necrotic areas were found in the left cerebellum, and a tumor with large liquefied clot within it in the right cerebellum. Pathologically, bilateral cerebellar tumors were confirmed as the metastases from the thymoma in the epithelial type.

Brain Neoplasms↗
PubMed1988

Evaluation of long-term results of bicuspidalization annuloplasty for functional tricuspid regurgitation. A seventeen-year experience with 133 consecutive patients.

Between 1968 and 1985, 133 consecutive patients underwent bicuspidalization annuloplasty for moderate to severe functional tricuspid regurgitation associated with mitral or combined mitral and aortic valve disease. Over this period, the incidence of tricuspid valve replacement was only 2.3% (3/136 patients). There were 18 early deaths (13.5%) in the entire series--three (5.0%) of 60 patients in the last 5 years of the study--and 10 late deaths (8.7%). Actuarial survival rate for the entire series, excluding early deaths, was 91.0% +/- 3.0% at 10 and 17 years. There were seven reoperations (6.1%) on the tricuspid valve, needed because of residual or recurrent mitral valve lesions after the initial operation. Actuarial rates of freedom from reoperation on the tricuspid valve were 93.6% +/- 3.0% (10 years) and 69.7% +/- 16% (17 years) for the entire series: 78% +/- 10% (15 years) for the open mitral commissurotomy plus tricuspid annuloplasty group (44 patients); 90% +/- 9.0% (15 years) for the mitral plus tricuspid annuloplasty group (10); 75.2% +/- 22% (17 years) for the mitral replacement plus tricuspid annuloplasty group (58); and 92.6% +/- 7.0% (16 years) for the combined aortic and mitral valve surgery plus tricuspid annuloplasty group (21). Ninety-eight percent of the survivors were in New York Heart Association class I or II postoperatively. Of 21 randomly selected patients investigated by pulsed Doppler echocardiography, 14 (67%) had no regurgitation or grade 1/4 tricuspid regurgitation and the remaining seven (33%) had grade 2/4 regurgitation postoperatively. Our experiences suggest that bicuspidalization annuloplasty can be a reliable method in the vast majority of patients with functional tricuspid regurgitation.

Actuarial Analysis↗
PubMed1988

Acute liver dysfunction after modified Fontan operation for complex cardiac lesions. Analysis of the contributing factors and its relation to the early prognosis.

Acute liver dysfunction was analyzed in 15 patients who received a modified Fontan operation for single ventricle in nine (atrial isomerism, seven) and tricuspid or mitral atresia in six. Nine patients had elevation of serum glutamic-pyruvic transaminase levels above 1000 U/L during the first week. As an analysis of postoperative liver function during the first week, the highest values of serum glutamic-pyruvic transaminase and total bilirubin and the lowest prothrombin time were scored from 0 to 4 within each parameter, and totaled to give a liver dysfunction score. The liver dysfunction score was 0 to 2 (no or trivial injury) in five patients, 3 to 5 (mild) in two, and 6 to 11 (moderate or severe) in eight (53.3%). The group operated on for single ventricle had a higher incidence (67%) of a liver dysfunction score of 6 or higher than the other group (33%). A multivariate analysis for the prediction of the liver dysfunction score mainly from early postoperative hemodynamics showed the highest correlation with cardiac index, followed by urine output, systolic arterial pressure, and central venous pressure. One patient required plasmapheresis. Four died early (less than 1 month); three of these had a liver dysfunction score of 6 or higher. Those with scores of 6 or above had higher serum glutamic-pyruvic transaminase levels at 1 month after operation than those with scores less than 5. In three patients (single ventricle), hepatic venous oxygen saturation was monitored and showed a marked decrease to below 20% with subsequent acute liver dysfunction. These results indicate that acute liver dysfunction appears to occur in patients with complex lesions after a modified Fontan operation from possible hepatic hypoperfusion and that low cardiac output may be more crucial than high central venous pressure alone.

Acute Disease↗
PubMed1987

The role of ventricular and cisternal drainage in the early operation for ruptured intracranial aneurysms.

In a series of 177 patients with ruptured supratentorial aneurysms we studied retrospectively the results of early and delayed operation without aggressive removal of subarachnoid blood clots but ventricular and cisternal drainage. The early and delayed groups were comparable demographically and neurologically. The overall results for the early group were a good outcome in 65%, poor outcome in 10% and death in 24%, compared to 53, 20 and 27% respectively in the delayed group. Thus, patients with an early operation and CSF drainage had better results. Permanent ischaemic neurological deficits due to cerebral vasospasm accounted for the poor outcome in 10 and 21% of the patients in the early and delayed groups, respectively and rebleeding accounted for the poor outcome in 5 and 10% in the early and delayed groups respectively. The mean amount of haemoglobin in the cerebrospinal fluid from cisternal drainage was 6.4 g, corresponding to about 40 ml of whole blood, during the 12-day period after SAH. The level was higher in patients with larger subarachnoid clots or with symptomatic vasospasm than in those with smaller clots or without such vasospasm. Early operation combined with ventricular and cisternal drainage is considered to be a useful surgical method for patient with a ruptured aneurysm.

Adult↗
PubMed1987

Intracranial meningiomas in infancy.

We report on two infants with meningioma under the age of 1 year. One is an 11-month old male infant with a fibroblastic meningioma without dural attachment to the right frontal lobe. The other is an 8-month-old male infant with a hemangiopericytic meningioma in the posterior fossa arising from the right petrous ridge. Both tumors were totally removed. Twenty-four infant meningiomas reported in the literature, including our two cases, were reviewed.

Age Factors↗
PubMed1987

An extended middle fossa approach combined with a suboccipital craniectomy to the base of the skull in the posterior fossa.

A new approach to the base of the skull in the posterior fossa is described. This approach involves removing the petrous bone without any injury to the labyrinth, and dividing the superior petrosal sinus and tentorium cerebelli. A combined suboccipital craniectomy is used for excision of the portion of tumors that extended inferiorly. Total or subtotal removal of tumors was performed in 11 patients and partial removal in 3 patients, without any operative mortality. The facial nerve was preserved in all patients and hearing was retained in 9 of 12 patients. This approach is useful for large tumors located around the clivus.

Adolescent↗
PubMed1987

Preoperative left ventricular function: minimal requirement for successful late results of valve replacement for aortic regurgitation.

Postoperative survival and left ventricular function were studied in 62 patients who underwent aortic valve replacement for isolated, chronic aortic regurgitation between 1978 and 1985. The average follow-up period was 3.8 years. There were three in-hospital and six late deaths. Five (56%) of the nine postoperative deaths were of cardiac-related causes. The mean 7 year survival rate was 83 +/- 5%. Preoperative left ventricular end-systolic volume index was the most important indicator (p less than 0.001) for subsequent cardiac death. The 6.5 year survival rate was 92 +/- 4% for patients with an end-systolic volume index less than 200 ml/m2 compared with 51 +/- 16% for those whose index was greater than 200 ml/m2. None of the 48 patients with an end-systolic volume index less than 200 ml/m2 died of cardiac-related causes. Twenty-three of the 48 patients with an end-systolic volume index less than 200 ml/m2 (Group 1) and 6 of the 12 patients with a higher index (Group 2) underwent repeat catheterization 26 months postoperatively. Preoperative afterload, assessed by end-systolic wall stress, was elevated in both groups, but decreased postoperatively, becoming identical to the afterload in 20 normal control subjects. Although the preoperative ejection fraction was depressed in both groups, the great majority of patients in Group 1, compared with none in Group 2, exhibited normal ejection fraction postoperatively. Thus, in patients who recently underwent surgery for aortic regurgitation, satisfactory late results in both long-term survival and reversal of left ventricular dysfunction were obtained when the preoperative end-systolic volume index was less than 200 ml/m2.

Adolescent↗
PubMed1987

Meningioangiomatosis not associated with von Recklinghausen's disease.

We report a rare case of meningioangiomatosis unassociated with von Recklinghausen's disease. The patient was a 30-year-old woman with a 25-year history of seizures. The lesion was confined to the right temporal cortex and consisted of a proliferation of angiomatous blood vessels and meningocytic cells. Her seizures have been well controlled after excision of the lesion.

Adult↗
PubMed1987

[Intracranial meningioma of an infant: a case report].

An 11-month-old male infant with intracranial meningioma is presented. Intracranial meningiomas in infancy under the age of 1 year are extremely rare, and only 22 cases have been reported previously. The authors reviewed the clinical and pathological findings of these meningiomas including our case. The patient feel ill with convulsive attacks followed by unconsciousness at 11 months of age without any other neurological deficit. Computed tomographic scannings revealed a high density lesion in the frontal region. The tumor was located entirely in the frontal lobe 2 cm anterior to the Sylvian vein and was removed en bloc. It was 3 X 3 X 3 cm in diameter and 10 g in weight. Histological diagnosis was of fibroblastic meningioma. He was discharged two weeks after the operation without any neurological deficits. Several characteristic features of meningiomas in infant under 1 year old were drawn from the review of literature in comparison with those of meningiomas in adult. 1) Predominant sex was male (16/23). 2) All meningiomas developed in the supra-tentorium. 3) Eight of 18 tumors being described did not have the dural attachment. 4) Nine of 16 tumors showed cyst formation. 5) The most cases were histologically diagnosed benign (17 of 22), and 15 cases was fibroblastic meningioma.

Brain↗
PubMed1987

[Behavior of left ventricular filling after left ventricular aneurysmectomy: evaluation by pulsed Doppler echocardiography].

The pattern of diastolic flow velocity was studied using pulsed Doppler echocardiography to evaluate postoperative left ventricular (LV) diastolic function in patients who underwent left ventricular aneurysmectomy. This study involved 16 patients who experienced ischemic heart disease from January 1985 to April 1986. The patients were categorized in two groups; the aneurysm group comprised by seven patients undergoing aneurysmectomy, and the bypass group which included nine patients undergoing only coronary artery bypass grafting. Pulsed Doppler studies were performed five to 22 days before, and at an average of 12 days after surgery. Preoperative cardiac catheterization and cineangiography were performed and, myocardial infarct size was estimated by the Wagner's method. Using pulsed Doppler echocardiography, LV filling dynamics were assessed by the peak velocity in the rapid filling phase (R), the peak velocity in the atrial contraction phase (A), and the ratio of A to R (A/R ratio) of the mitral flow velocity pattern. All data were average in five consecutive beats. 1. The estimated myocardial infarct size (%MI) in both groups before surgery was 38.5% in the aneurysm group and 32.5% in the bypass group, and there was no significant difference between these groups. 2. The preoperative cardiac index (2.9 in the aneurysm group vs 2.8 1/min/m2 in the bypass group), left ventricular end-diastolic pressure (16.1 vs 17.3 mmHg), and left ventricular ejection fraction (0.43 vs 0.36) were not significantly different between the two groups. 3. The preoperative A/R ratio was 1.5 in the aneurysm group and this was significantly higher than that of the bypass group (1.2).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

[A case of primary intracranial malignant lymphoma associated with gastric carcinoma].

A case of synchronous multiple primary neoplasms, an intracranial malignant lymphoma and a gastric carcinoma, is presented. A 63-year-old man was admitted to our hospital with complaints of dizziness and a floating sensation on gait. A CT scan after admission, revealed a well-defined, nodular high density area in the left frontal lobe, which was markedly enhanced by the contrast medium. In order to rule out a metastatic brain tumor, examinations were performed as a consequence, and, the gastric carcinoma was found. A partial removal of the brain tumor and a gastrectomy were performed in two stages. Pathologically, the diagnosis of the brain tumor indicated a malignant lymphoma of large cell type, and that of the gastric carcinoma was an adenocarcinoma. The patient received postoperative irradiation and chemotherapy and was discharged in a good condition. He died of pneumonia 21 months after the operation. Necropsy revealed a marked atrophy of the brain without recurrence of the malignant lymphoma and no recurrence of a gastric cancer.

Adenocarcinoma↗
PubMed1987

Reconsiderations of indications for open mitral commissurotomy based on pathologic features of the stenosed mitral valve. A fourteen-year follow-up study in 347 consecutive patients.

From January 1972 to December 1984, 347 consecutive patients underwent open mitral commissurotomy for mitral stenosis. Commissurotomy was performed in 86% of 404 patients undergoing mitral valve operations for stenosis during the same period. These 347 patients had three different types of mitral stenosis: type I, mobile cusps without subvalvular changes (43 patients); type II, thickened cusps with subvalvular changes (210 patients); type III, rigid cusps with severe subvalvular changes (94 patients). Concomitant mild mitral regurgitation was seen in 87 patients (25.1%) and mild to moderate valve calcification in 61 patients (17.6%). There were eight early deaths (2.3%) and 12 late deaths (3.5%), yielding an actuarial survival rate of 94.6% (excluding early deaths) 14 years after operation. There were 17 reoperations (5.0%) The actuarial rates of freedom from reoperation were as follows: 83.8% at 14 years for the entire series; 73.5% for type I stenosis; 88.9% for type II; 84.0% for type III; 91.7% for mitral stenosis with calcification; 82.6% for stenosis without calcification; 90.6% for pure mitral stenosis; and 52.5% for stenosis combined with regurgitation (p less than 0.05). Postoperative effective mitral valve areas calculated according to the hydraulic formula were 2.52 cm2 (mean) at rest and 3.06 cm2 during exercise in six patients with type I stenosis, 2.21 and 2.48 cm2, respectively, in 10 with type II, and 1.85 and 1.87 cm2, respectively, in 14 with type III. Our data clearly demonstrated that open mitral commissurotomy provided excellent long-term results with acceptable valve function and a low incidence of reoperation in patients with pure mitral stenosis not combined with regurgitation, even when associated with severe subvalvular changes with or without mild to moderate valve calcification.

Adolescent↗
PubMed1986

Architecture of the media of the arterial vessels in the dog brain: a scanning electron-microscopic study.

The architecture of the media of arterial vessels in dog brain was investigated using scanning electron microscopy. The arrangement and shape of the circularly-oriented smooth muscle cells varied with vessel diameter: The arteries (greater than 100 microns in diameter) had 4-10 layers of spindle-shaped smooth muscle cells; the muscular arterioles (30-100 microns), 2-3 layers of spindle-shaped smooth muscle cells; the terminal arterioles (10-30 microns), a compact layer of spindle-shaped smooth muscle cells with more dominant nodular or rod-like processes and thin lateral processes; and the precapillary arterioles (5-15 microns), a less compact layer of branched smooth muscle cells. Longitudinally-oriented muscles were observed in the medio-adventitial border. The distribution and arrangement of these muscles varied with vessel size: in the large arteries (greater than 300 microns in diameter), at the branching sites only; in the small arteries (100-300 microns), at both the branching and non-branching sites; in the muscular arterioles, at both the branching and non-branching sites in a reticular arrangement with some muscle cells having an "asteroid" appearance; in the terminal arterioles, only "asteroid-like" muscle cells were found at the branching and non-branching sites.

Animals↗