Biomedical subjects

T Sakaki

Publications and source records attributed to T Sakaki.

At least 235 records · Page 13Linked to original sources

PubMed1993

The effect of acetylcholinesterase inhibitor (SDZ ENA 713) for r-CBF and focal cerebral ischaemia.

The purpose of the present study was to examine the effect of Acetylcholinesterase inhibitor (AChEI) on r-CBF (group A) and its protecting effect on focal ischaemic cell damage (group B). The pial arterial diameter and the r-CBF were measured with a width analyzer and with a laser Doppler flowmeter through a cat cranial window on the ectosylvian gyrus. The ischaemic area was measured histologically. We used intravenous injection of AChEI([-])(S)-N-ethyl-3-[(1-dimethyl- amino)ethyl]-N-methyl-phenylcarbamate, SDZENA 713, Sands Pharmacy) to block AChE. Twenty minutes after injection AChEI (0.6 mg/kg) the pial arteriole dilated 108.5 +/- 1.8% and the r-CBF increased 115.4 +/- 2.6%. The pial arteriole dilated maximally to 137.6 +/- 6.5% at 120 minutes after injection and the r-CBF increased maximally to 137.1 +/- 19.5% at 60 minutes after injection. The protecting effect was evaluated using cats and 1 hour of occlusion of the middle cerebral artery (MCA). Twenty minutes after injection of AChEI, the pial arteriole dilated to 116.7 +/- 2.4% and the r-CBF increased to 111.9 +/- 2.6% significantly. During MCA occlusion the r-CBF decreased to 24.7-41.4% in group B and 25.1-32.6% in sham group (group C). The pial arteriole dilated 145.0-184.0% in group C and 150.7-171.6% in group B during MCA occlusion and 30 minutes after reperfusion the pial arteriole returned to 120.0 +/- 3.3% in group C and 123.4 +/- 11.3% in group B. There were no significant changes in the r-CBF and the vessel diameter between group B and C during the 2 hours after reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMed1993

Suprasellar embryonal carcinoma which developed ten years after local radiation therapy for pineal germinoma.

We recently encountered a case of suprasellar embryonal carcinoma which developed 10 years after local radiation therapy for pineal germinoma. This 29-year-old male was admitted because of abnormal behavior, disturbed consciousness, and increased intracranial pressure. Computed tomography and magnetic resonance imaging disclosed a tumor spreading from the suprasellar region to the third ventricle and the anterior horn of the left lateral ventricle, accompanied by fresh hemorrhage within the tumor. He underwent subtotal removal of the tumor, followed by chemotherapy with cisplatin and etoposide. The tumor was histologically rated as embryonal carcinoma with differentiation into yolk sac tumor and choriocarcinoma.

Adult↗

PubMed1993

Effects of flumazenil during administration of midazolam on pial vessel diameter and regional cerebral blood flow in cats.

We implanted closed cranial windows in ten cats in order to observe the response of pial vessel diameter by microscopy using fluorescein isothiocyanate-labeled dextran and regional cerebral blood flow (rCBF) by laser Doppler flowmetry during administration of midazolam and reversal with flumazenil. Midazolam was given at 0.8 mg.kg-1 x min-1 for 10 min and maintained at 0.04 mg.kg-1 x min-1 for 50 min (total 10 mg.kg-1). The diameter of arterioles and venules and rCBF showed no significant change. During the last 10 min of midazolam administration, flumazenil, given at 0.1 mg.kg-1 x min-1 for 10 min (total 1 mg.kg-1), caused an increase of MAP and rCBF (P < 0.01) at 5 min after infusion and diameter of larger arterioles (> 50 microns) and venules (50-100 microns) were dilated (P < 0.05). These results indicate that midazolam does not affect the diameter of cerebral arterioles and venules; however, the reversal effects of flumazenil against midazolam are transient vasodilation of larger arterioles accompanied by an elevation of MAP, and an increase in CBF.

Animals↗

PubMed1993

Localization of E-cadherin adhesion molecules in human gingiva and gingival carcinoma.

Immunohistochemical investigations were carried out on the localization and expression of the Ca(2+)-dependent intercellular adhesion molecule E-cadherin in human gingiva and gingival carcinoma. Although E-cadherin did not appear in the parakeratinized layer of either clinically healthy or inflamed gingiva, it did appear strongly in the prickle layer and somewhat more weakly in the basal layer. Immunogold particles reactive to anti-E-cadherin monoclonal antibody in the electron microscopic findings were localized only in the vicinity of the desmosomes of the prickle and basal layers. In the case of gingival carcinoma, although E-cadherin was strongly expressed in the cells surrounding the keratinized region in the cancer nests, the expression decreased towards the marginal portion of the cancer nests. The distribution of E-cadherin in these cells may be dependent on the condition of the cancer cells that are potentially invasive. These findings suggest that cells of the parakeratinized layer of gingiva and cells of the marginal portion of the gingival carcinoma nests may easily detach or invade. In addition, the findings suggest that the gingival carcinoma used in this study tended to be invasive.

Aged↗

PubMed1993

The effect of a new calcium antagonist, TA3090 (clentiazem), on experimental transient focal cerebral ischemia in cats.

BACKGROUND AND PURPOSE: TA3090 (Clentiazem) has been shown to have cerebrovascular protective properties in three experimental studies. An in vivo investigation was undertaken to determine its effects on pial arteries and cerebral blood flow and its therapeutic value in transient focal cerebral ischemia. METHODS: This experiment was divided into two protocols. In the first, 200 or 400 micrograms/kg per hour TA3090 was administered continuously for 3 hours in cats without ischemic insult (n = 6 for each group). The effects on pial arteries and cerebral blood flow were estimated. In the second protocol, 400 micrograms/kg per hour TA3090 (treated group, n = 14) or physiological saline (control group, n = 10) was administered 5 minutes before 1 hour of middle cerebral artery occlusion in cats. The effects on the pial arteries and cerebral blood flow were observed continuously, followed by autoradiography for a quantitative measurement of cerebral blood flow 5 hours after middle cerebral artery recirculation. The volumes of the cerebral edema and infarct were estimated by planimetry from cerebral preparations made for histological examination. RESULTS: Pial arteries dilated by up to approximately 10% in the 400-micrograms group and 3% in the 200-micrograms group 30 minutes after administration of TA3090. Increases in cerebral blood flow of about 10% in the 400-micrograms group and 2% in the 200-micrograms group were demonstrated with laser Doppler flowmetry. In the second protocol, dilatation of pial arteries was significantly smaller during and after the ischemic insult in the treated group compared with the control group (p < 0.01). Cerebral blood flow decreased less significantly during ischemia (p < 0.01 at the end of ischemia) and increased less significantly after ischemia (p < 0.01 at the end) in the treated group compared with the control group. Autoradiography showed a more remarkable increase in cerebral blood flow due to luxury perfusion in the cerebral cortex, which was mainly perfused by the middle cerebral artery on the affected side in the control group (p < 0.01). Cerebral blood flow in the cerebral cortex, thalamus, and caudate nucleus on the contralateral side of the treated group increased by about 20% more than that of the control group (p < 0.05). Cerebral edema and infarction were much smaller in the treated group than in the control group (p < 0.01). CONCLUSIONS: 1) TA3090 dilates pial arteries and increases cerebral blood flow in normal brain regions in a dose-response fashion; 2) in ischemic regions compared with those in untreated animals, TA3090 results in a lesser reduction of cerebral blood flow during ischemia and in a lesser degree of hyperemia during reperfusion; 3) TA3090 is associated with less pial artery dilatation during ischemia, presumably due to improved collateral flow; and 4) the improved hemodynamic state with TA3090 is associated with significant reduction of cerebral edema and infarct size.

Animals↗

PubMed1993

Clinical studies of de novo aneurysms.

Although multiple cerebral aneurysms ae well recognized, a new aneurysm has only rarely been documented after successful treatment for an aneurysm elsewhere. In our consecutive series of 986 patients with intracranial saccular arterial aneurysm collected from 1975 to 1990, nine patients who had previously unverified (hence, de novo) intracranial aneurysms and ruptures at intervals of 4 to 7.5 years after clipping of an initial aneurysm are presented here. All nine had undergone successful treatment of a previous aneurysm; preoperative and postoperative angiography showed not only successful clipping of the first aneurysm but also no incidence of multiple aneurysms. These patients had suffered from hypertension before their second admission. Seven of the nine patients were treated surgically. All patients had experienced angiographical or symptomatic vasospasm after the first subarachnoid hemorrhage. In the second admission however, seven patients who underwent the surgery for a new aneurysm suffered from no vasospasm in spite of the prominent second subarachnoid hemorrhage. Two of the nine patients died of primary brain damage due to the hemorrhage and underwent necropsy. A histological study of a new aneurysm demonstrated the same findings as that of a usual saccular aneurysm. This clinical study of our patients suggests that it is important to control blood pressure for protection against a new aneurysm formation.

Adult↗

PubMed1993

Preparation of di-O-triphenylmethyl-(trityl-)cyclomalto-octaoses, and isolation and characterization by "hex-5-enose degradation" of four positional isomers.

Four regioisomeric ditritylated derivatives of cyclomalto-octaose (1, cG8), namely, 6(I),6(n)-di-O-trityl-cG8S have been prepared by the reaction of 1 with chlorotriphenylmethane in pyridine and isolated by high-performance liquid chromatography. The regiochemical determination of the four ditrityl-substituted derivatives has been achieved by means of the "hex-5-enose degradation," followed by examination of the products by fast-atom bombardment-mass spectrometry.

Carbohydrate Sequence↗

PubMed1993

Dissecting aneurysm of the posterior inferior cerebellar artery--case report.

A 29-year-old male presented with a dissecting aneurysm of the left posterior inferior cerebellar artery manifesting as left lateral medullary syndrome due to brainstem ischemia. Extirpation of the aneurysm and anastomosis of the occipital artery to the posterior inferior cerebellar artery were performed simultaneously. The dissecting aneurysm was confirmed by histological examination of the surgical specimen.

Adult↗

PubMed1993

Efficacy of superficial temporal to middle cerebral artery anastomosis against hemodynamic stroke.

The effect of superficial temporal artery-middle cerebral artery anastomosis on regional cerebral blood flow (rCBF) was measured on 31 patients with ischemic cerebrovascular diseases. rCBF was measured on the precentral and superior temporal gyri during surgery using the thermal diffusion technique. The mean rCBF was significantly lower than controls before anastomosis, but increased significantly after. Severer clinical symptoms were associated with lower rCBF. The rCBF increased significantly in patients with transient ischemic attack, reversible ischemic neurological deficit, and minor and major completed stroke. All 31 patients demonstrated dysautoregulation, both before and after anastomosis. However, the rCBF had increased above the ischemic threshold during hypotension, achieving a reserve capacity to prevent hemodynamic stroke.

Adult↗

PubMed1993

High-performance liquid chromatography analysis of chondroitin sulfate isomers in human periodontium.

We investigated the chondroitin sulfate in human periodontal samples (gingiva, periodontal ligament, cementum and alveolar bone) collected for orthodontic reasons. Glycosaminoglycans (GAGs) were extracted from the periodontium by enzyme digestion, and unsaturated disaccharide isomers of chondroitin sulfate were obtained by chondroitinase ACII and hyaluronidase digestion. The isomers were analyzed by high-performance liquid chromatography. Chondroitin sulfate was found in all four types of periodontal tissue; its unsaturated disaccharide isomers consisted in delta Di-0S, delta Di-6S, delta Di-4S, delta Di-diSE and delta Di-triS. These four types of periodontal tissue showed different molar ratios of the unsaturated disaccharides. The ratio of delta Di-4S to delta Di-6S was greater in the calcified than in the uncalcified tissue.

Adolescent↗

PubMed1993

Changes in synovial fluid N-acetyl-beta-glucosaminidase activity in the human temporomandibular joint with dysfunction.

beta-Glycosidases (N-acetyl-beta-glucosaminidase, N-acetyl-beta-galactosaminidase, beta-glucuronidase) were assayed in temporomandibular joint (TMJ) synovial fluid obtained from 23 patients with closed lock TMJ internal derangement (ID), four with closed-lock TMJ osteoarthritis (OA), and 13 with normal controls (N). Synovial fluid was collected from the upper joint space after injecting 1.5 ml of 1% lidocaine three times. The specific activity of N-acetyl-beta-glucosaminidase increased significantly both with ID (p < 0.01) and with OA (p < 0.001), along with increases in the activity of N-acetyl-beta-galactosaminidase (p < 0.05 with ID and p < 0.01 with OA) and in beta-glucuronidase (p < 0.05 both with ID and OA). The N-acetyl-beta-glucosaminidase activity with OA was also significantly higher (p < 0.001) than with ID. These findings suggest that N-acetyl-beta-glucosaminidase activity in the TMJ synovial fluid reflects the degree of TMJ dysfunction.

Acetylglucosaminidase↗

PubMed1993

Clinicopathological study on craniopharyngioma with sebaceous differentiation.

We presented 2 cases of craniopharyngioma, which showed sebaceous differentiation. Both cases shared the following features: 1) neuroradiological detection of a cystic tumor accompanied by calcification, 2) clear yellowish fluid detected in the cyst during surgery, 3) histological rating as an adamantinomatous type, 4) the presence of a nest-like distribution of multivacuolated cells in the innermost layer of the cyst.

Child↗

PubMed1993

[A case of intracerebral AVM fed by the anterior ethmoidal artery].

Only 27 cases of dural AVM fed by the anterior ethmoid artery have been reported in the literature. Their nidi were usually in the dura mater. In our case, the nidus was located in the brain parenchyma, although its feeder was the dural artery. A 75-year-old man was admitted to our department because of disturbed consciousness. CT scan showed intracerebral hemorrhage in the left frontal region with ventricular perforation, and subarachnoid hemorrhage in the suprasellar cistern. Left carotid angiography revealed an AVM in the anterior cranial fossa, fed by the anterior ethmoidal artery and drained by a cortical vein, which was dilated with some vascular sacs. A left frontal craniotomy was performed. The subcortical hematoma was removed, and then, after retracing the frontal lobe, two feeders penetrating the dura mater were identified and clipped. The nidus of the AVM with aneurysmal vascular dilatation could be seen on the cortical surface. It was coagulated and removed en-bloc. Histologically, the malformation consisted of thickened dilated veins and distorted small arteries. Postoperative angiography revealed no vascular anomaly. The patient was discharged with mild aphasia and mild right hemiparesis.

Aged↗

PubMed1993

[Chronic encapsulated intracerebral hematoma associated with cavernous angioma: case report and review of the literature].

We reported a case of chronic encapsulated intracerebral hematoma associated with cavernous angioma. A 71-year old female was admitted with a history of frontal headaches at intervals of about 3 months for the last one year. Plain CT scan showed a round mass of heterogeneous high density in the left medial frontal lobe. The outer surface of the mass was enhanced with contrast material. MRI demonstrated the mass as a high signal intensity on T1-weighted image and low intensity with laminated structure on T2-weighted image. MR angiogram depicted the mass as a mottled high signal intensity. The left internal carotid artery angiogram revealed no abnormal shadows and vessels. These findings suggested some form of a thrombus although its underlying pathogenesis was unclear. On January 20, 1992, a bifrontal craniotomy was performed. A whitish well-demarcated mass was seen in the left cingulate gyrus through a small corticotomy. We could not identify any branches feeding the mass. The cross-section of the mass disclosed a uniform thrombus encapsulated by a thick wall. Histological studies of the wall confirmed a cavernous angioma within the outer collagenous layers. Chronic encapsulated hematoma, which was first reported by Hirsh in 1981, has represented a separate entity and 25 such cases have been documented in the literature. These reports suggested that the compression and/or destruction of the surrounding tissue caused by the hemorrhage would mask the existence of the cavernous angioma or vascular malformation. If an encapsulated hematoma were encountered during an operation, surgeons should pay attention not to overlook the residual capsule encompassing the cavernous angioma or vascular malformation.

Adolescent↗

PubMed1993

[A characteristic magnetic resonance image of a dissecting aneurysm in the vertebrobasilar system].

Recently several reports of dissecting aneurysm in the vertebrobasilar system have been published. We report the effectiveness of MRI for the detection of a dissecting aneurysm in the vertebrobasilar distribution system. A 47 year-old male [correction of female] was admitted to our hospital due to right occipitalgia and the right Wallenberg's syndrome. Computed tomography disclosed no abnormalities. Cerebral angiogram showed the pearl and string sign of the right vertebral artery, which suggested a dissecting aneurysm. MRI exhibited the infarct area at the right dorsolateral part of the medulla oblongata, which corresponded to right Wallenberg's syndrome. It disclosed high intensity ring-like findings circumscribing a low intensity spot of the lumen of the right vertebral artery. This high intensity was thought to be the hematoma between the intima and the media at the subacute stage. Its high intensity corresponded to the site of the dissecting aneurysm and of Wallenberg's syndrome. These findings are thought to be useful in the diagnosis of a dissecting aneurysm of the vertebral artery.

Aortic Dissection↗

PubMed1993

[A rare case of middle fossa neuroepithelial cyst accompanied by chronic subdural hematoma].

We reported a rare case of middle fossa neuroepithelial cyst accompanied by chronic subdural hematoma. An eight-year-old boy was admitted to our hospital due to headache, disturbed consciousness and right hemiparesis. CT disclosed a left marginal high density in the left subdural space and remarkable midline shift. MRI showed a hematoma in the left to temporal tip extending to the chronic subdural hematoma. Radiological examinations revealed a cystic lesion with chronic subdural hematoma. An operation was performed to remove the hematoma. Intraoperatively, the hematoma in the cyst and the chronic subdural hematoma were observed. Histopathological diagnosis of the cyst wall was neuroepithelial cyst. The relationship between the neuroepithelial cyst and chronic subdural hematoma was discussed.

Brain Diseases↗

PubMed1993

[Spinal extradural angiolipoma: a case report].

Growth of angiolipoma of the central nervous system is a rare occurrence. Only about 40 cases can be collected in the literature. A 67-year-old man was admitted because of intermittent severe pain in both legs after walking. He had chillness in both legs during the past 5 years which gradually worsened. MR image showed a spinal mass lesion at the level of Th12 to L1. The lesion was isointense on T1-weighted image and slightly hyperintense on T2-weighted image. The tumor was located on the left side of the spinal cord and was markedly enhanced after intravenous Gd-DTPA. At the operation, a soft, dark-red mass was found situated in the epidural space at the level of Th12 to L1, which was totally removed. On histological examination, the tumor was shown to be mainly composed of mature fatty cells and of numerous blood vessels with enlarged lumens. Postoperative course was uneventful and the symptoms subsided during the following few months.

Aged↗

PubMed1993

[Experimental study of acute spinal cord injury: a histopathological study].

The microscopic appearance of a rat spinal cord which was acutely compressed by aneurysmal clip for one minute, was investigated 15 minutes, 30 minutes, 1 hour, 3 hours and 6 hours after the injury. Although the resulting small hemorrhagic lesion involved primarily only the central gray matter of the injured portion 15 minutes after compression injury, hemorrhage, necrosis and edema in the central gray matter enlarged progressively until 3 hours after injury. Petechial hemorrhage, necrosis and edema were observed in the surrounding area one hour after spinal compression. Then these pathological changes extended rostrally and caudally, but their extension was more significantly remarkable in the rostral side than in the caudal side 3 hours after compression. It was observed that leukocytes begin to infiltrate into the injured capillary walls and plug up the capillary lumen 30 minutes after the injury. Three hours following the injury, leukocytes (lymphocyte, macrophage) extravasated into the surrounding spinal tissue. From these histopathological observations, we reached the following conclusions. A. Secondary injuries play an important role in grave impairment of neurological function of the spinal cord following acute trauma. B. Pathological findings (hemorrhage necrosis and edema) extend more prominently to the rostral side, because the direction of spinal blood flow may be rostral in the thoracic spinal cord. C. Severe disturbance of intraspinal capillary blood flow leading to grave spinal damage may be evoked, because leukocytes infiltrate into the capillary around the injured area and plug up the their lumen about 30 minutes after the injury.

Acute Disease↗