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Biomedical subjects

K Sako

Publications and source records attributed to K Sako.

At least 73 records · Page 4Linked to original sources
PubMed1992

[A ruptured aneurysm at the peripheral collateral circulation of the anterior choroidal artery in a patient with moyamoya disease: a case report].

This 42-year-old man experienced a sudden onset of occipital headache. Neurological examination revealed a moderately disturbed consciousness and a moderate left hemiparesis. CT scan disclosed a hugh hematoma in the right temporo parietal lobe without intraventricular hemorrhage. A cerebral angiography demonstrated typical findings of moyamoya disease and a small saccular aneurysm at the peripheral portion of the right anterior choroidal artery, which was dilated at the collateral circulation to the parietal lobe. The hematoma was removed at once by a craniotomy. He became alert but mild hemiparesis persisted. MRI disclosed a small signal-void lesion lateral to the trigone of the right lateral ventricle. The angiography repeated three weeks after the removal of the hematoma showed the unchanged size of the aneurysm. Direct surgery for the aneurysm was performed via the right parietal transcortical approach. The aneurysm was reached under the guidance of the intraoperative angiography. Trapping of the parent artery and the excision of the aneurysm were performed. On the basis of the presence of an internal elastic lamina at the neck of the aneurysm, the surgical specimen was histologically verified to be a true aneurysm. Since the collateral circulation was well preserved during surgery, no worsening of the neurological manifestation was observed. In view of the unfavorable prognosis for a moyamoya patient with this type of the aneurysm, which often results in a massive ventricular or intracerebral hemorrhage, surgery directed to the aneurysm itself should be considered.

Adult↗
PubMed1992

[A septated syringomyelia with a dramatic clinical course in a young patient with MELAS; a case report].

This is a report of a young girl who showed a recurrence of acute worsening and remission of neurological manifestations, with consistent MRI demonstration of transaxial septated syrinxes in the cervical and the lumbar spinal cord in addition to a tight filum terminale. This 8 year-old girl had developed normally since her birth until August 1989 when she developed a gait disturbance. This worsened acutely on January 1, 1990, with the additional manifestation of a urinary bladder disturbance. General examination failed to show any abnormality or scoliosis. Neurologic examination revealed a monoparesis of the right lower extremity with muscle atrophy and pyramidal tract sign. Fecal constipation and urinary retention were noted. The MRI T1 weighted sagittal image demonstrated an incontinuous low intensity signal in the C1-C7 as well as in the T12-L2 without swelling of the cord. The axial image clearly demonstrated the septations in the syrinx which looked like eye glasses. No definite Gd enhancement was demonstrated. Chiari malformation was not associated, but the tethered cord was well identified. With the administration of steroid, she showed a marked improvement of neurological manifestations. She was able to urinate without difficulty and also walk by herself. For one month thereafter she remained well with minor neurological deficits until she developed a worsening of the gait disturbance with a newly manifested weakness of the left upper extremity. Sensory impairment was also demonstrated below L3. In contrast to the worsening of the clinical symptoms, no definite change in the abnormalities found by MRI was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis, Lactic↗
PubMed1991

HA1077, a novel calcium antagonistic antivasospasm drug, increases both cerebral blood flow and glucose metabolism in conscious rats.

The effects of a novel calcium antagonistic antivasospasm drug, HA1077, on local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) were studied in 33 anatomically discrete regions of the brain in conscious rats, using the quantitative autoradiographic [14C]iodoantipyrine and [14C]2-deoxyglucose techniques. HA1077 was infused i.v. over a 30-min period (1 or 3 mg/kg). HA1077 significantly increased LCBF in 9 of 33 sites in rats given 1 mg/kg, and in 14 of 33 sites in rats given 3 mg/kg compared to the control group given vehicle. Significant increases in LCGU were also noted in 16 of 33 sites in rats given 3 mg/kg. HA1077 increased both cerebral blood flow and glucose metabolism in conscious rats.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

Benign parotid tumors: a 24-year experience.

The medical records of 125 patients benign parotid neoplasms surgically treated over a 24-year period were retrospectively reviewed; 128 tumors were excised. These included 90 pleomorphic adenomas, 33 Warthin's tumors, 3 benign lymphoepitheliomas, and 2 oncocytomas. The surgical procedures consisted of 2 local excisions, 6 enucleations, 88 superficial parotidectomies, 13 subtotal parotidectomies, and 3 radical parotidectomies. The morbidity rate was 49%. There was one total permanent facial nerve paralysis (0.7%), four (3%) partial permanent facial nerve paralysis, five (5%) transient total facial nerve paralysis, and 32 (25%) partial transient facial nerve paralysis. After a median follow-up of 84 months, there was one recurrence (0.7%). A superficial parotidectomy is the minimum procedure that should be performed for the treatment of a benign parotid neoplasm.

Adolescent↗
PubMed1991

Effects of induced hypertension on blood flow and capillary permeability in rats with experimental brain tumors.

To study the possibility of enhancing the delivery of antineoplastic agents to tumor tissue, we conducted an experimental study using induced hypertension with angiotensin II in rats with experimental brain tumors. Drug delivery was evaluated by measuring local cerebral blood flow (LCBF) and regional cerebral capillary permeability with quantitative autoradiography. There was no significant difference of LCBF in the central region of tumor tissue between the control group and the induced hypertension group. LCBF in the peripheral region of tumor tissue in the induced hypertension group was significantly higher than that in the control group. On the other hand, despite induced hypertension, no significant changes in the regional cerebral capillary permeability were observed between the groups. These results indicate that delivery of the lipid-soluble antineoplastic agents, which depend upon cerebral blood flow, can be enhanced by induced hypertension.

Aminoisobutyric Acids↗
PubMed1991

Relationship between 22Na distribution and cerebral blood flow in ischemic gerbil brain.

Sodium transport in the early postischemic period was studied using Mongolian gerbils with right common carotid artery ligation. [22Na]sodium chloride ([22Na]NaCl) was infused immediately after, 10 minutes before, and 4 hours before carotid ligation, and the 22Na distribution was measured in symptomatic animals by autoradiography 1 hour after ischemia. Regional cerebral blood flow was determined by [14C]iodoantipyrine autoradiography. The specific gravity of the brain was measured in symptomatic gerbils 1 and 2 hours after carotid ligation by a gradient column. There was a low uptake of 22Na in the ischemic core and a high uptake in the ischemic periphery when the tracer was given 10 minutes before or immediately after ischemia. In contrast, tracer given 4 hours before ischemia showed an increased radioactivity in both the ischemic core and periphery. It is suggested that increased sodium in the ischemic core is due to a decreased sodium clearance rate and increased sodium in the ischemic periphery is due to some active transport process.

Animals↗
PubMed1991

[Spontaneous disappearance of aneurysm after total removal of accompanying intracranial arteriovenous malformation. Case report].

A 55-year-old male was hospitalized with severe headache. On admission, neurological examination revealed no abnormal findings. Plain computed tomography (CT) showed a slightly high-density area in the medial surface of the right parietal lobe. A marked enhancement in the same region was noted in enhanced CT. Cerebral angiography showed an arteriovenous malformation (AVM) in the medial surface of the right parietal lobe and two aneurysms on the right pericallosal artery which fed the AVM. In addition, a saccular aneurysm was noted at the anterior communicating artery. It was not possible to treat the AVM, two aneurysms nearby the AVM, and the unruptured anterior communicating artery aneurysm simultaneously with a single craniotomy. It was therefore decided to perform surgery for the AVM and two aneurysms nearby the AVM prior to clipping of the anterior communicating artery aneurysm. Total excision of the AVM and two aneurysms nearby the AVM was performed. Cerebral angiography performed 18 days after surgery revealed no AVM and also reduction in size was noted of the anterior communicating artery aneurysm. Three months later, repeated cerebral angiography showed disappearance of the aneurysm. This was further confirmed 15 months after surgery by angiography. From the literature, 117 cases of coexistence of AVM and aneurysms of the brain were collected and classified into three types according to their anatomical and hemodynamic correlation. It is suggested that hemodynamic stress, due to increased blood flow caused by the AVM, played a major role in the development of the aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamics↗
PubMed1990

Uncoupling of local blood flow and metabolism in the hippocampal CA3 in kainic acid-induced limbic seizure status.

Limbic seizure status was induced by microinjection of kainic acid into a unilateral amygdala in rats. Two hours after kainic acid injection, distant neuronal cell damage was produced, especially in the hippocampal CA3 on the kainic acid-injected side. In order to elucidate the mechanism of this neuronal cell damage, local cerebral glucose utilization and local cerebral blood flow were studied by means of an autoradiographic method using [14C]2-deoxyglucose and [14C]iodoantipyrine during kainic acid-induced limbic seizure status. These studies were performed 2 h after kainic acid microinjection into a unilateral amygdala. Both local cerebral glucose utilization and local cerebral blood flow were remarkably increased in the limbic system, ventrobasal complex of the thalamus, septal nucleus, nucleus accumbens, caudate nucleus, substantia nigra and hypothalamus on the kainic acid-injected side. In the hippocampus, local cerebral glucose utilization increased 2.6 times control in CA1 and 4.1 times in CA3, whereas the rates of increase in local cerebral blood flow were similarly low in CA1 and CA3: 1.2 and 1.4 times control, respectively. The results demonstrated that the degree of uncoupling of local cerebral glucose utilization and local cerebral blood flow were higher in CA3 than in CA1, and also suggested that relative hypoxia occurred in CA3 in this high degree of uncoupling, resulting in pyramidal cell damage in CA3 in kainic acid-induced limbic seizure status.

Animals↗
PubMed1990

Measurement of cerebral blood flow, cerebral blood volume, and cerebral capillary permeability in glioma-bearing rats.

Effective chemotherapy and radiation therapy of brain tumors require knowledge of the cerebral circulatory dynamics involved. In this study, regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), and regional cerebral capillary permeability (rCP) were measured in Wistar King Aptekman rats bearing experimental KEG-1 gliomas. These parameters were assessed by autoradiography with 14C-iodoantipyrine, 14C-deoxyglucose-labeled red blood cells, and 14C-aminoisobutyric acid, respectively. rCBF within the tumor was approximately one third that in the contralateral cortex and was consistently higher in the periphery than in the center of the tumor. In the periphery of the tumor, rCBV was approximately twice that in the contralateral cortex, but it was very low in the center of the tumor. Throughout the tumor, rCP was sharply increased relative to that measured in the contralateral cortex, and the increase was especially pronounced in the central portion. Thus, rCBF, rCBV, and rCP each appeared to vary within the tumor, implying that the combined use of lipid- and water-soluble chemotherapeutic agents is reasonable. Measurement of these parameters may also provide indices of radiation sensitivity.

Animals↗
PubMed1990

Diffuse low-density areas in white matter on CT scans after intracarotid ACNU infusion--report of three cases.

Since 1984, we have treated 11 malignant glioma patients with intracarotid infusion of ACNU [1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)- 3-nitrosourea hydrochloride] in addition to surgical removal and irradiation. We experienced three patients, who showed clinical manifestation of leukoencephalopathy and computed tomographic (CT) findings of diffuse low-density areas in the white matter on the side of ACNU infusion. Two of the three patients showed an additional CT finding of ring enhancement in the temporo-occipital region. The histological diagnosis of the first case was radiation necrosis, while that of the others was recurrent tumor with coagulation necrosis in the surrounding brain. Our experience suggests that intracarotid ACNU infusion increases the hazard of radiation necrosis, and the optimum dose and effective mode of administration should be evaluated.

Brain↗
PubMed1990

[The effects of disturbance of cerebral venous drainage on focal cerebral blood flow and ischemic cerebral edema].

The effect of disturbance of cerebral venous drainage on acute ischemic cerebral edema and cerebral circulation were studied by measuring local cerebral blood flow (LCBF) and local changes in brain water content using a middle cerebral artery (MCA) occlusion model. Rats were anesthetized with halothane and the stem of the left MCA was occluded. Disturbance of cerebral venous drainage was induced by bilateral occlusion of the external jugular veins, i.e., the right external jugular vein was cannulated and the left one was occluded by a clip. LCBF was measured by the 14C-iodoantipyrine (14C-IAP) autoradiographic method at 2 hours after MCA occlusion. Local changes in brain water content were studied 2 hours after MCA occlusion by measuring the specific gravity of cerebral tissue in the gradient column with bromobenzene and kerosene. The control rats which underwent the same anesthesia and surgical procedure including the MCA occlusion and cannulation into the right external jugular veins, but which did not undergo occlusion of the left external jugular veins, were prepared and studied at the same time after MCA occlusion. In the rats with bilateral occlusion of the external jugular veins, the external jugular venous pressure was evaluated up to about 8 mmHg (100 mmH2O) (control: 1.3 mmHg). At 2 hours after MCA occlusion, LCBF in the ischemic core was decreased. The ischemic area was more extensive in the rats with bilateral occlusion of the external jugular veins compared with the controls. Furthermore, specific gravity of the brain was decreased in the entire left MCA territory in the rats with bilateral occlusion of the external jugular veins.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

Regional calcium accumulation and kainic acid (KA)-induced limbic seizure status in rats.

The sites of calcium accumulation were studied by 45Ca autoradiography during kainic acid (KA)-induced limbic seizure in rats. Two hours after KA injection into unilateral amygdala, calcium accumulated in CA3 of the hippocampus, lateral septal nucleus and thalamic reticular nucleus on KA-injected side. Those sites coincided with the sites where neuronal cell damage appeared 4 h after KA injection. These results suggested that regional calcium accumulation might be responsible for neuronal cell loss induced by seizures.

Animals↗
PubMed1989

Surgical salvage for recurrent "early" glottic cancers.

A 25-year retrospective study of 143 early (T1 and T2 N0) glottic cancer, patients was done to determine the recurrence rate following initial radiation therapy, the surgical salvage rate, and incidence of cervical lymph node metastases. Radiation therapy gave a 5-year cure rate of 78% for stage I and 57% for stage II. Total laryngectomy for recurrent squamous cell carcinoma had a 5-year salvage rate of 66% for stage I and 61% for stage II recurrent tumors. The overall 5-year cure rate with initial and second therapy for stage I and stage II glottic cancers was 93% and 83%, respectively.

Adult↗
PubMed1989

Multiple primary cancers in squamous cell cancer of the head and neck.

A retrospective review of 832 patients with squamous cell cancer of the head and neck between 1961 and 1985 was carried out to determine the incidence of multiple primary cancers (MPC) at the time of autopsy and the number who died of the second cancer. The overall risk of developing a second MPC of the head and neck, lung, or esophagus from treatment of first head and neck cancer to time of autopsy was 4.04% per year.

Carcinoma, Squamous Cell↗
PubMed1989

Recurrent malignant salivary gland neoplasms.

Recurrent salivary gland malignancies present difficult therapeutic decisions and poor prognosis in many instances, and treatment becomes of a palliative nature only. As many of the salivary gland malignancies we see are of the recurrent type, the following study was done to determine the efficacy of a vigorous attempt at retreatment. During the period January 1, 1960, through December 31, 1984, 352 patients with major and minor salivary gland tumors were evaluated at our institution. There were 149 benign lesions and 203 patients with malignant tumors. Of these, 99 patients had recurrent and metastatic tumors that had been treated initially elsewhere. Thirty-three of these patients were able to be treated with curative intent: surgery, 21; surgery plus radiation, 9; radiation therapy alone, 2; and radiation plus chemotherapy, 1. The 5 year survival with no evidence of disease was achieved in three patients with surgery alone and two patients with surgery plus radiation therapy. The group of five patients was comprised of two patients with adenoid cystic carcinomas of the parotid, one with intermediate grade mucoepidermoid carcinoma of the parotid, one, sebaceous cell carcinoma of the parotid, and one, adenoid cystic carcinoma of an accessory salivary gland. The results of this study serve to re-emphasize the relative poor yield of attempts at retreatment of loco-regional recurrence of salivary gland tumors.

Adult↗
PubMed1989

Surgical management of squamous cell carcinoma of the floor of the mouth.

Treatment failure and survival in 209 patients with squamous cell carcinoma of the floor of the mouth treated with surgery as the single curative modality are reported. Fifty percent of the patients had stage III and IV disease. The primary tumor was excised with 1 to 2 cm margins and the mandible was resected in 73 percent of the patients; 77 percent underwent radical neck dissection. No cures were observed in 11 patients with involved surgical margins on permanent section. For 198 patients with uninvolved margins, determinate survival at 5 years for all stages was 49 percent and 69, 64, 46, and 26 percent for stages I through IV (p less than 0.01). The most common sites of initial and ultimate treatment failure were the neck (42 of 72 patients) and distant metastases (33 of 53 patients), respectively. Treatment of the neck is identified as an unresolved problem in the management of early stage disease. Recent improvements in survival for stage III and IV disease are accounted for, in part, by adequate surgical resection.

Adult↗
PubMed1989

Management of advanced glottic carcinomas.

One hundred twenty-eight patients with T3 or T4 glottic cancers were treated by initial surgery; 59 had a total laryngectomy and 69 had total laryngectomy with regional node dissection. Fifty-eight percent of the total laryngectomy group and forty-nine percent of the total laryngectomy with neck dissection group remained free of disease for 5 or more years. Forty-seven percent (60 of 128 patients) treated surgically developed regional recurrences requiring further treatment. Nine patients had evidence of widespread metastases, leaving 51 suitable for salvage radiotherapy. Twenty-three percent (12 of 51 patients) were salvaged with radiotherapy given for postoperative recurrences. Twenty-five patients received an initial 6,600 rads to larynx and neck with curative intent, 28 percent of whom remained free of disease for 5 or more years. Seventeen percent of patients were salvaged with one laryngectomy for persistent or recurring tumors. Initial total laryngectomy gave better survival figures for advanced glottic carcinoma.

Adult↗