Biomedical subjects

S Sakaki

Publications and source records attributed to S Sakaki.

At least 127 records · Page 7Linked to original sources

PubMed1991

Recurrence after incompletely resected acousticus neurinomas.

It is known that the recurrence rate is high when an acoustic neurinoma is incompletely excised, but the details of the process of recurrence are still unclear. We reviewed the recurrence of acoustic neurinomas, as evaluated by computed tomography (CT) or magnetic resonance imaging (MRI), in 51 consecutive patients over the past 10 years who underwent tumor resection and had postoperative follow-up by CT or MRI. The factors promoting recurrence related to incomplete excision of tumor were analyzed. Total resection of the tumor was performed in 22 patients (43%), nearly total resection in 17 patients (33%) and subtotal resection in 12 patients (24%). The recurrence rates were 29% (5 of 17 patients) and 25% (2 of 8 patients) for nearly total and subtotal resection, respectively, whereas no recurrence occurred following total resection. Of the patients having nearly total resection, all recurrences arose from residual tumor in the internal auditory meatus (5 of 12 patients). In contrast, there were no recurrences from residual tumor at the site of the brain stem (none of 4 patients). Acoustic neurinomas should be totally removed through neurosurgical and neuro-otological approaches whenever possible. If a small fragment of tumor is left in the internal auditory meatus due to fear of damaging the facial or cochlear nerves, it should be strictly followed up by CT or MRI.

Adolescent↗

PubMed1991

[A case report of right ventricular myxoma which was found by cardiac systolic murmur at a medical examination].

Right ventricular myxoma is very rare with the only 19 cases in the Japanese literature. We report on a 26-year-old woman with a right ventricular myxoma which was found by cardiac systolic murmur at a medical examination and successfully excised. Echocardiography and coronary angiography is very useful in deciding the location of insertion on the right ventricle. Right atriotomy prior to right ventriculotomy was important for right ventriculotomy and necessary for complete excision. Clinical characteristics, and diagnostic and therapeutic aspects are discussed.

Adult↗

PubMed1991

[Timing of operation based on evaluation of postoperative left ventricular contractility in patients with aortic regurgitation].

To evaluate the effect of aortic valve replacement on left ventricular function in aortic regurgitation, the ratio of end-systolic wall stress to end-systolic volume index (ESS/ESVI) and standard ejection phase indexes of left ventricular function were measured angiographically in 29 patients with isolated, chronic aortic regurgitation before and an average of 26 months after aortic valve replacement. The patients were divided into three groups based on preoperative left ventricular volume at end-systole (ESVI); 12 patients had an ESVI smaller than 100 ml/m2 (group I), 11 had an ESVI of 100 to 200 ml/m2 (group II) and 6 had an ESVI greater than 200 ml/m2 (group III). Postoperatively, end-diastolic volume index and ESVI decreased markedly in all 3 groups and end-systolic stress also decreased. Systolic pump performance assessed as ejection phase indexes improved in all groups with group I and group II showing normal or near-normal ejection fraction, while group III still had a depressed ejection fraction. Left ventricular contractile function as assessed by ESS/ESVI improved significantly in each group postoperatively. After operation, group I patients had normal values. However, both group II and group III still had a subnormal ratio, suggesting a depressed contractility despite normal or near normal systolic pump performance. Surgical correction for aortic regurgitation should be considered before a preoperative ESVI exceeds 100 ml/m2, to preserve postoperative left ventricular contractility.

Adult↗

PubMed1991

[A case of meningioangiomatosis in an infant].

We report here a rare case of meningioangiomatosis in an infant, not associated with von Recklinghausen's disease. A 14-month-old female was admitted because of seizures. Neurological findings on admission were normal. Computed tomography showed a slightly high density mass with marked contrast enhancement in the left temporoparietal lobe. Magnetic resonance image (MRI) revealed a slightly hypointensive lesion surrounded by an isointensive band on T1-weighted image, and a hyperintensive lesion surrounded by a slightly hypointensive band on T2-weighted image. Brain edema was shown to a certain extent around the lesion on MRI. Left carotid angiography demonstrated a slightly upward shift of the left middle cerebral artery, but no abnormal vascularity was shown. A temporoparietal craniotomy was performed. A yellowish red, elastic soft tumor was observed in the left temporal lobe. The tumor resembled hyperemic hypertrophic gyri and was well demarcated. Total removal of the tumor was performed. Pathological diagnosis was meningioangiomatosis. The patient is still doing well 3 years and 5 months after the operation. There was no evidence of recurrence on computed tomography at the 3-year follow up. She didn't have any stigmata, such as café au lait spots or neurofibromas suggesting von Recklinghausen's disease.

Angiomatosis↗

PubMed1991

[The long-term results of patients over 70 years old after coronary artery bypass surgery].

We have assessed the long-term results of heptagenerians after isolated coronary artery bypass surgery from 1979 to 1989 in 32 patients over 70 (mean 72) years old using actuarial techniques. In these patients, the long-term results could not be properly assessed because many other factors other than cardiac events influenced their survival. Accordingly, we compared our subjects with the general population matching the operative age and sex characteristics from life tables (= matched population). There was no operative mortality. The 5 year and 9 year survival rates were 93% and 31%. In the matched population, the 5 year and 9 year survival rates were 81% and 59%. The survival rate between the two groups was not significantly different. We concluded that the long-term results of coronary artery bypass surgery in patients over 70 years were similar to those of the matched population. Therefore, coronary artery bypass surgery should be offered to older patients for usual indications.

Aged↗

PubMed1991

[Primary malignant lymphoma of the skull presenting as a growing mass in the forehead; a case report].

A rare case of primary malignant lymphoma of the skull was reported. A 74-year-old woman was admitted to our hospital complaining of a growing mass in her forehead where she had had minor trauma one month previously. On admission, neurological findings were normal and an elastic hard tumor (6 x 6 x 2 cm) was found in the right frontal region. Computed tomography (CT) showed a large soft tissue mass in the subcutaneous tissue and a small mass in the ethmoid sinus, with erosion at the inner and outer tables of the frontal bone. Magnetic resonance imaging revealed a low intensity area in the bone marrow beneath the tumor. Right carotid angiography showed that the tumor was fed by branches of the ophthalmic artery in the arterial phase and stained in the capillary phase. Partial excision of the tumor was performed, but the affected bone was left because of her advanced age, even though thinning and spicular formation of the frontal bone were observed beneath the tumor in places. Pathological examination showed the tumor to be a malignant lymphoma of non-Hodgkin and diffuse mixed type. Postoperatively, systemic examinations were performed by 99mTechnetium-MDP bone scanning, 67Gallium citrate scanning, bone marrow puncture, and CT scanning, without any evidence of systemic lymphoma. The patient received postoperative chemotherapy with Cyclophosphamide, Doxorubicin HCl, Vindesine Sulfate, Prednisolone, and complete remission has been achieved for the 8 months since the operation.

Aged↗

PubMed1990

Timing of operation for aortic regurgitation: relation to postoperative contractile state.

With angiography and pressure measurement, we determined left ventricular volume, wall stress, and systolic performance in 30 patients with aortic regurgitation before and after successful aortic valve replacement. End-systolic wall stress was greatly elevated preoperatively and decreased to normal postoperatively. Systolic pump performance assessed as ejection phase indexes was severely depressed preoperatively and improved to normal or near-normal postoperatively in most patients. The ratio of end-systolic wall stress to end-systolic volume index (ESS/ESVI), an index of myocardial contractility, was greatly decreased before operation. Postoperatively, the ratio increased in all patients, becoming normal in 12 of the 13 patients who had a preoperative ESS/ESVI of 2.9 or greater. However, 15 of 17 patients in whom the ESS/ESVI ratio was less than 2.9 still had subnormal ratios, which indicates the presence of irreversible contractile dysfunction. Stepwise multivariate analysis showed that preoperative ESS/ESVI was the only independent discriminator of postoperative normalization of the contractile function as assessed by ESS/ESVI. After aortic valve replacement, myocardial contractile state does not return to normal in a considerable number of patients. It is important to offer aortic valve replacement for aortic regurgitation before the chance for a good functional result is lost. The ESS/ESVI ratio may be a useful index in determining the timing of operation in patients with aortic regurgitation.

Adult↗

PubMed1990

Successful treatment of adult Arnold-Chiari malformation associated with basilar impression and syringomyelia by the transoral anterior approach.

A case of adult type I Arnold-Chiari malformation associated with basilar impression, syringomyelia, atlantoaxial dislocation, and occipitalization of the atlas is reported. Preoperative magnetic resonance imaging clearly revealed evidence of severe anterior compression of the cervicomedullary junction due to basilar impression and a sharp clivoaxial angle. Therefore, transoral anterior decompression and fusion were performed, resulting in an improvement of the patient's neurologic signs and symptoms. Postoperative magnetic resonance imaging showed an obvious reduction of the tonsillar herniation and syringomyelia, as well as an improvement of the cervicomedullary compression.

Adult↗

PubMed1990

Intracranial nonspecific inflammatory granuloma.

A case of nonspecific inflammatory granuloma arising from the dura mater near the hypoglossal canal is reported. A 38-year-old woman developed an isolated left hypoglossal nerve palsy. Computed tomography and magnetic resonance imaging demonstrated an enhanced tumorous lesion at the inner orifice of the left hypoglossal canal. Skull x-ray was normal, and cerebral angiography showed no vascular abnormalities. Examination of the cerebrospinal fluid showed mild pleocytosis with a predominance of lymphocytes. Systemic examination revealed no abnormalities. The tumor was removed completely and pathologic investigation revealed that it was an inflammatory granuloma. The patient's history and laboratory data, however, failed to suggest the underlying disease, and histopathologic examination did not indicate any special type of granuloma. Therefore, the lesion was diagnosed as a nonspecific inflammatory granuloma.

Adult↗

PubMed1990

Left ventricular ejection performance, wall stress, and contractile state in aortic regurgitation before and after aortic valve replacement.

Left ventricular ejection performance, wall stress, and contractile state were evaluated in 35 patients with chronic aortic regurgitation. Cineangiography and pressure measurements were obtained before and a mean of 26 months after aortic valve replacement, and data were compared with those from 30 normal control subjects. The relation between quantitative changes in wall stress and changes in ejection fraction after surgery was determined. Preoperatively, end-systolic stress was elevated in patients with aortic regurgitation (218 +/- 45 vs. 160 +/- 23 kdynes/cm2 [mean +/- SD] for control subjects, p less than 0.01), and ejection fraction was depressed (0.46 +/- 0.11 vs. 0.65 +/- 0.05, p less than 0.01). End-systolic stress decreased postoperatively (151 +/- 41 kdynes/cm2, p less than 0.01) and ejection fraction increased (0.58 +/- 0.11, p less than 0.01). The magnitude of increase in ejection fraction correlated significantly and negatively (r = -0.65) with the quantitative change in end-systolic stress after surgery. Contractile function, as assessed by the ejection phase index-end-systolic stress relation, did not significantly change: 23 of 35 patients preoperatively and 18 of 35 patients postoperatively had values that clearly fell below the 95% confidence limit of the ejection fraction-end-systolic stress relation for controls. After surgery, individual ejection fraction-end-systolic stress relationships demonstrated a shift parallel to the regression curve for the control subjects. Moreover, persistent postoperative left ventricular hypertrophy was significantly associated with persistent contractile dysfunction. Thus, late improvement in left ventricular ejection performance after aortic valve replacement can be attributed to the reduction in end-systolic stress. Contractile function itself was not improved by surgery. Persistent postoperative hypertrophy may be a marker for myocardial contractile dysfunction.

Adolescent↗

PubMed1990

Architecture of the medial smooth muscle of the arterial vessels in the normal human brain: a scanning electron-microscopic study.

The architecture of the medial smooth muscle of arterial vessels in normal human brains was investigated using scanning electron microscopy. We could divide the arterial vessels into four subdivisions according to the number of the circular muscle cells. The arteries (greater than 100 microns in diameter) had 4-20 layers of circular smooth muscle cells; individual circular muscle cells were spindle-shaped and occasionally had branches at their ends. Multidirectional muscle cells were observed in the medio-adventitial border only at the branching sites in large arteries (greater than 300 microns), but at both branching and non-branching sites in the small arteries (100-300 microns). The nonterminal arterioles (30-100 microns) had 2-3 layers of circular muscle cells; most of the circular muscle cells had nodular or rod-like processes at their branched ends. Multidirectional muscle cells were most frequently observed in the medio-adventitial border in this subdivision at both branching and non-branching sites. The terminal arterioles (10-30 microns) had a single layer of circular muscle cells. Multipolar (stellate in appearance) smooth muscle cells were mainly seen in the medio-adventitial border at branching sites. The precapillary arterioles (7-10 microns) had a single layer of branched muscle cells; individual muscle cells had 2-4 circular branches on both sides of the central bulges.

Adolescent↗

PubMed1989

[Visualization of epileptic lesions using single photon emission computed tomography (SPECT) with N-isopropyl-p-(123I) iodoamphetamine after intravenous loading of bemegride--report of a case].

Single photon emission computed tomography (SPECT) was performed 30 minutes and 4 hours after injection of 111 MBq (3 mCi) N-isopropyl-p-(123I) iodoamphetamine (IMP) which was injected 5 minutes after the completion of intravenous bemegride loading. A 31-year-old female with simple partial seizures evolving to complex partial seizures evolving to generalized tonic-clonic convulsive seizures with a history of hospitalization, suffering from low-grade fever, generalized convulsive seizures, and impaired consciousness at the age of 27 years was studied. Angiographic examinations, X-CT, MRI, CSF examinations, and interictal neurological examinations were normal. She suffered from clonic convulsions in her right shoulder and arm, and hallucinations and dysmnesia which were characteristic of temporal lobe epilepsy. More recently she suffered from impaired consciousness once or twice a month. While the controlled IMP-SPECT study was normal, the IMP-SPECT study examined after the activation by intravenous bemegride loading showed the pattern of a regional increased uptake of IMP in the epileptic lesions corresponding with the epileptic symptoms, and a surrounding border of decreased uptake which might be the inhibition of surrounding neuronal activity and metabolism. In conclusion, the bemegride loading IMP-SPECT study could be a potential diagnostic method in patients with seizures whose epileptic lesions were not determined by the conventional methods or in whom the surgical interventions were considered, by reason of its capability to demonstrate positively the epileptic lesions.

Adult↗

PubMed1989

Outcome in elderly patients with ruptured intracranial aneurysm.

Sixty-nine elderly patients over 65 years old with ruptured aneurysms had a significantly worse outcome than 192 younger patients with respect to overall management results and operative results (p less than 0.01). The results of an early operation were better in the elderly patients with grade I-III than in those receiving a delayed operation. Concomitant diseases significantly influenced the results in elderly patients (p less than 0.05). It is possible that an early operation results in the better outcome in elderly patients by decreasing the incidence of delayed ischemic complications and preventing rebleeding.

Adult↗

PubMed1989

Impairement of vascular reactivity and changes in intracellular calcium and calmodulin levels of smooth muscle cells in canine basilar arteries after subarachnoid hemorrhage.

We examined vascular reactivity to various vasoconstrictors and dilators, and the changes in calcium-calmodulin levels in canine basilar arteries after subarachnoid hemorrhage (SAH). Contractile responses to noradrenaline, serotonin, and potassium chloride were markedly attenuated at 48 hours (P less than 0.05), and further attenuated at 7 and 14 days after SAH (P less than 0.01). Dilation responses to calcium antagonist were maintained at 48 hours after SAH, but were markedly reduced at 7 and 14 days after SAH (P less than 0.05). Transmission electron micrographs of the basilar artery showed contraction of the media between 48 hours and 7 days and degeneration of smooth muscle cells over the 7 days after SAH. Electron microscopic cytochemical examination for calcium showed that intracellular deposits of calcium pyroantimonate increased in smooth muscle cells of basilar arteries at 1 hour after the first intracisternal injection of blood (early spasm), but decreased in smooth muscle cells at 48 hours after SAH (at the beginning of delayed vasospasm). They decreased further in the vessels 7 days after SAH. The calmodulin contents in the basilar arteries were decreased slightly at 6 hours, and significantly (P less than 0.05) at 48 hours after SAH, as determined by radioimmunoassay and phosphodiesterase assay. Therefore, it is considered that delayed vasospasm is not simply an active contraction of the vessels, but a functional or structural derangement of contractile elements of smooth muscle cells after 48 hours after SAH.

Animals↗

PubMed1989

Uncommon type of meningiomas with conspicuous plasmo-lymphocytic infiltration. An immunohistochemical and histochemical study.

Two cases of meningioma revealing conspicuous plasmo-lymphocytic tissue and hyalinized fibrous tissue components are reported. Histopathological examination of the plasmo-lymphocytic infiltration was performed. Both lesions showed polyclonality of plasma cells as revealed by positive reactions for IgG and paraimmunoglobulin kappa- and lambda-light chains, and amyloid infiltration into the fibrous stroma and blood vessel walls. The histochemical and immunohistochemical characteristics of the lesion in relation to its etiology are briefly discussed.

Adult↗

PubMed1989

Intracerebellar hematoma in a term newborn secondary to an angiomatous malformation--case report.

A neonate born after an uncomplicated, full-term pregnancy was evaluated for acute-onset intermittent vomiting and bradycardia at 3 days of age. Computed tomography showed an intracerebellar hematoma and symmetrical dilatation of the ventricles. No abnormal vascularity was demonstrated by angiography. The hematoma and an angiomatous lesion in the cerebellum were removed through a suboccipital craniectomy when he was 21 days old. The histological diagnosis was angiomatous malformation. He is developing normally at 10 months of age. Arteriovenous malformation should be considered in the differential diagnosis of intracerebellar hematoma in any newborn whose delivery did not involve trauma or hypoxia and who has no hemorrhagic diathesis.

Adult↗

PubMed1989

[A case of Wyburn-Mason syndrome].

A extremely rare case of unilateral retinocephalic vascular malformation (Wyburn-Mason syndrome) was reported. A 5 year-old girl was seen to a ophthalmologist complaining of exophthalmus of her left eye after trauma on her face for the past 2 months. On ophthalmologic examinations, retinal arteriovenous malformation was recognized in her left eye and she was referred to neurosurgical service for the evaluation on occurrence of traumatic carotid cavernous fistula. Plain CT did not show any abnormality but enhanced CT revealed an abnormally enhanced lesion in the thalamus and basal ganglia and along to the left optic nerve. Left carotid angiography and vertebral angiography revealed a huge arteriovenous malformation in the left thalamus and basal ganglia extending to the left orbita. The arteriovenous malformation was fed from the C3 segment of the carotid artery, anterior, middle and posterior cerebral arteries, and drained to the internal cerebral vein and basal vein. The intraorbital part of the malformation was mainly fed from the external cerebral artery. She was diagnosed as Wyburn-Mason syndrome. We stressed in the paper that enhanced CT was useful for the diagnosis of the Wyburn-Mason syndrome.

Angiography, Digital Subtraction↗

PubMed1989

Depressed myocardial contractility and normal ejection performance after aortic valve replacement in patients with aortic regurgitation.

Left ventricular cineangiography and pressure measurement were performed in 33 patients with chronic aortic regurgitation before and after aortic valve replacement and in 25 normal control subjects. Stress and volume were analyzed. The 33 patients were divided into three groups based on preoperative end-systolic volume index: 15 with an index of less than 100 ml/m2 (group I), 12 with an index of 100 to 200 ml/m2 (group II), and six with an index of more than 200 ml/m2 (group III). Afterload estimated as end-systolic stress, which was significantly elevated in all groups before operation, returned to normal postoperatively. Systolic pump function improved postoperatively in all groups; group I and group II showing the most improvement with group III still having an abnormal ejection fraction. The ratio of end-systolic stress to end-systolic volume index, which is an index of contractile state that is relatively independent of preload and afterload, was abnormal in each group preoperatively. Postoperatively, the ratio improved in each group (from 2.8 +/- 0.5 to 4.8 +/- 0.9 for group I, from 1.4 +/- 0.3 to 3.2 +/- 0.6 for group II, and from 0.8 +/- 0.2 to 2.6 +/- 0.8 for group III, compared with 5.9 +/- 1.0 for control subjects). Group I had normal values whereas group II and group III had subnormal ratios, suggesting a depressed contractility. All 15 patients in group I had values that fell within the 95% confidence limits of the linear inverse relationship between ejection fraction and end-systolic stress for control subjects. Nine of the 12 patients in group II and all six in group III had values that fell below the 95% confidence limits of the normal ejection fraction-end-systolic stress relationship. Aortic valve replacement may reduce afterload and improve systolic pump function in many patients with aortic regurgitation. However, there is a subgroup of patients who, despite normal or near-normal pump performance as assessed by ejection fraction, have depressed myocardial contractility characterized by an abnormal relationship between end-systolic stress and either ejection fraction or end-systolic volume.

Adolescent↗