Biomedical subjects

T Sakaki

Publications and source records attributed to T Sakaki.

At least 145 records · Page 8Linked to original sources

PubMed1997

Genomic alterations in human glioma cell lines detected by restriction landmark genomic scanning.

Restriction landmark genomic scanning (RLGS) is a 2-dimensional gel analysis capable of detecting amplifications, deletions and rearrangements in genomic DNA. Using RLGS, we examined genomic DNA from each of 6 human-derived malignant glioma cell lines and from normal brain tissue samples. RLGS allows us to screen genomic DNAs as approximately 2,000 landmark sites in one procedure without any polymorphic markers. The resulting 2,000 spots in tumor samples were compared with those in normal brain. Six spots common to 5 of the 6 cell lines showed intensified signal, suggesting amplification of a tumor-specific DNA fragment. In addition, 25 spots common to 5 of the 6 lines showed a decrease in signal intensity, conversely indicating allelic loss of homozygous deletion. These results imply the existence of consistent genetic alterations in human glioma.

Brain Neoplasms↗

PubMed1997

An experimental model of intraoperative venous injury in the rat.

Intraoperative obliteration of cerebral veins occasionally causes unexpected severe complications, especially in elderly patients. However, very title information is available on the pathophysiology of cerebral venous circulation disturbance. Occlusion of cortical veins in rats by a photochemical thrombotic technique is a less invasive, clinically relevant and reproducible model that is suitable for the study of venous circulation disturbance. In the present study, 54 male Wistar rats were used. We examined changes of the cerebral venous flow pattern by fluorescence anglography and brain damage histologically in a one- or two-(cortical) vein occlusion model using a photochemical thrombotic technique. Approximately 30% (9 of 27) of animals in the single-vein occlusion group and 90% (15 of 17) of those in the two-vein occlusion group had microcirculation perturbation, which results very soon in the formation of venous thrombus accompanied by severe venous infarction. In addition, infarction size in the two-vein occlusion group (9.7 +/- 3.2%) was significantly larger than in the single-vein group (2.9 +/- 1.3%) (unpaired T-test, P < 0.01).In conclusion, the photochemical dye technique of attaining cerebral venous occlusion is a worth while addition to the study of circulation perturbations of the brain.

Journal Article↗

PubMed1997

Expression of growth inhibitory factor mRNA after focal ischemia in rat brain.

Growth inhibitory factor (GIF) is a small protein belonging to the metallothionein family that has the capacity to inhibit neuronal survival and neurite formation in vitro. This study was conducted to investigate the role of GIF in the brain afflicted with ischemic injury. We used the in situ hybridization technique and Northern blot analysis to study the changes in GIF messenger RNA (mRNA) expression in a rat focal ischemia model. On the first day, the expression tended to decrease in the hemisphere ipsilateral to the injury. It returned to normal levels on the second day except for the central area of the middle cerebral artery (MCA) territory. On the third and fourth day, the expression increased diffusely in the hemisphere of the affected side, including the subcortical area. Two weeks after ischemia, the GIF mRNA expression increased again but only in the peri-infarcted area. Down-regulation of GIF on the first day in the cortex ipsilateral to the infarction might promote neurite sprouting. The subsequent increase in GIF mRNA expression on the third and fourth day might be a symptom of neurons attempting to inhibit excessive neurite outgrowth, or to protect themselves against toxicity caused by oxygen radicals. The later increase in the limited area around the infarction may be related to astroglial reaction. Growth inhibitory factor may play an important role in regulating the central nervous system after ischemic insults.

Animals↗

PubMed1997

Interlocking-clipping technique for giant aneurysms of the internal carotid artery: technical case report.

OBJECTIVE AND IMPORTANCE: Direct clipping of giant intracranial aneurysms is sometimes difficult. A unique technique using multiple fenestrated clips for closing a giant aneurysm is described. CLINICAL PRESENTATION: A 65-year-old woman presented with a 10-month history of headache and gait disturbance. Cerebral angiography disclosed an unruptured giant aneurysm of the right internal carotid artery. INTERVENTION: Surgical exposure confirmed the presence of a giant aneurysm with the splaying and incorporation of the parent artery and a number of perforating arteries originating from the dome. Four angled and three straight fenestrated clips were applied in tandem to the aneurysm to reconstruct the parent artery and preserve the perforating vessels. Through their blades and heads, the closely arranged clips were successfully interlocked. CONCLUSION: This "interlocking-clipping" technique is a modification of the tandem clipping technique. The aim of this approach is to enhance closing pressure and allow a more stable "seating" of the clips in giant cerebral aneurysms.

Aged↗

PubMed1997

Evaluating the effect of superficial temporal artery to middle cerebral artery bypass on pure motor function using motor activation single photon emission computed tomography.

OBJECTIVE: We evaluated and analyzed the effect of superficial temporal artery to middle cerebral artery bypass for internal carotid artery occlusion on pure motor function using motor activation single photon emission computed tomography. METHODS: Motor activation single photon emission computed tomographic (SPECT) images were obtained for nine patients who had undergone superficial temporal artery to middle cerebral artery anastomosis for symptomatic internal carotid artery occlusion. All motor activation SPECT images using the finger opposition task on the affected side were obtained before bypass surgery and at 1 week, 1 month, and 3 months after bypass surgery. The results of motor activation single photon emission computed tomography were expressed as negative or positive. RESULTS: Before bypass surgery, the resting SPECT images revealed reduction of cerebral blood flow (CBF) on the affected side in all nine patients. The results of motor activation single photon emission computed tomography in three patients were positive. One week after bypass surgery, the results of the resting and motor activation CBF studies did not demonstrate any marked changes. One month after bypass surgery, the resting CBF increased in four patients. The results obtained for two of the patients revealed preoperative positive motor activation. The results of motor activation single photon emission computed tomography obtained for five patients were positive. Three months after bypass surgery, eight patients experienced improvement in the resting CBF, and the results of motor activation single photon emission computed tomography obtained for seven patients were positive. Among these, the results of preoperative motor activation single photon emission tomography obtained for four patients were negative. CONCLUSION: Superficial temporal artery to middle cerebral artery bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT images. From the preoperative motor activation study, it was concluded that patients with preoperative positive motor activation could attain the effect of bypass earlier than patients with preoperative negative motor activation.

Aged↗

PubMed1997

Bow Hunter's stroke caused by a nondominant vertebral artery occlusion: case report.

OBJECTIVE AND IMPORTANCE: Bow hunter's stroke is a consequence of vertebrobasilar insufficiency as a result of mechanical occlusion or stenosis of the vertebral artery at the C1-C2 level by head rotation. In most cases, a dominant vertebral artery is involved. No case of bow hunter's stroke as a result of mechanical occlusion of a nondominant vertebral artery has ever been reported. CLINICAL PRESENTATION: We describe a rare case of Wallenberg's syndrome caused by occlusion of a nondominant vertebral artery induced by head rotation. The patient complained of vertigo and paresthesia of the left face and the right extremities when he rotated his head 45 degrees or more to the right. INTERVENTION: Dynamic angiography revealed that the left vertebral artery was smaller than the right, terminated in a branch of the posteroinferior cerebellar artery, and was stretched and completely occluded at the C1-C2 level with the head rotated 45 degrees to the right. The right vertebral artery was normal when the head was rotated to either the right or the left. Three-dimensional enhanced computed tomography with the head rotated 45 degrees to the right revealed that the left vertebral artery was stretched and occluded by dislodgment between C1 and C2. Cerebral blood flow scintigraphy with head rotation demonstrated that blood flow was decreased in the lower portion of the left cerebellar hemisphere. C1-C2 posterior fixation was performed to prevent life-threatening neurological accidents. CONCLUSION: We emphasize that the diagnosis of bow hunter's stroke should be based not only on angiographic findings but also on hemodynamic studies with head rotation.

Aged↗

PubMed1997

Chondroitin sulfate isomers in synovial fluid of healthy and diseased human temporomandibular joints.

Synovial fluid was collected from the superior articular cavity of the temporomandibular joint in patients with unilateral internal derangement and joint pain whose contralateral joint was healthy. Glycosaminoglycans were liberated by digestion with pronase E, and precipitated with cetylpyridinium chloride and ethanol. Unsaturated disaccharide isomers of chondroitin sulfate, obtained following chondroitinase ACII digestion, were analyzed by high-performance liquid chromatography. Analytic data indicated that deltaDi-0S and deltaDi-6S were often found in chondroitin sulfate from the fluid of the diseased joints. The amounts of deltaDi-0S and deltaDi-6S differed significantly between synovial fluid samples from the diseased and healthy joints. Comparison of the relative proportions of the unsaturated disaccharides in the synovial fluid with previously reported values for several tissues, indicated that the chondroitin sulfate originated from articular cartilage, with possibly some contributions from soft connective tissues and serum present in the synovial fluid. These results suggest that chondroitin sulfate in the synovial fluid provides a useful indicator of the degree of internal derangement of the temporomandibular joint.

Adult↗

PubMed1997

Specific changes in human brain after hypoglycemic injury.

BACKGROUND AND PURPOSE: Very few reports are available on serial changes in the human brain after severe hypoglycemic injury. The aim of this study was to investigate sequential neuroradiological changes in brains of patients after hypoglycemic coma compared with those after cardiac arrest previously studied with the same methods. METHODS: We repeatedly studied CT scans and MR images obtained at 1.5 T in four vegetative patients after profound hypoglycemia associated with diabetes mellitus. RESULTS: In all patients, consecutive CT scans showed symmetrical, persistent low-density lesions with transient enhancement in the caudate and lenticular nuclei and transient enhancement in the cerebral cortex 7 to 14 days after onset. Serial MR images consistently revealed symmetrical lesions of persistent hyperintensity and hypointensity on T1- and T2-weighted images, respectively, in the caudate and lenticular nuclei, cerebral cortex, substantia nigra, and/or hippocampus from 8 days to 12 months after onset. CONCLUSIONS: Repeated MR images revealed specific lesions in the bilateral basal ganglia, cerebral cortex, substantia nigra, and hippocampus, which suggests the particular vulnerability of these areas to hypoglycemia in the human brain. We speculate that the localized lesions represent tissue degeneration, including some combination of selective neuronal death, proliferation of astrocytic glial cells, paramagnetic substance deposition, and/or lipid accumulation. The absence of localized hemorrhages on MR images in hypoglycemic encephalopathy is in marked contrast to the presence of regional minor hemorrhages in postischemic-anoxic encephalopathy.

Aged↗

PubMed1997

Dural arteriovenous fistula caused by jugular vein stenosis--case report.

A 32-year-old female presented with a dural arteriovenous fistula in the transverse-sigmoid sinus caused by stenosis of the left internal jugular vein. The feeding arteries were embolized, resulting in nearly complete disappearance of the fistula. This case supports the idea that dural arteriovenous fistula is an acquired lesion caused by intravenous hypertension.

Adult↗

PubMed1997

Fetal cavernous angioma--case report.

A neonate male who developed cavernous angioma was born with a severe intraventricular hemorrhage and intraparenchymal hemorrhage in the basal ganglia. magnetic resonance imaging revealed a large, non-enhanced hematoma that packed the lateral ventricle. Surgery on the 2nd day of life verified a cavernous angioma associated with minimal hemosiderin and gliosis. Fetal cavernous angiomas, unlike such malformations in other age groups, can present with a devastating hemorrhage because of the lack of gliosis in the surrounding brain.

Cerebral Hemorrhage↗

PubMed1997

Hypothalamic hamartoma associated with dural arteriovenous fistula of the transverse-sigmoid sinus--case report.

A 32-year-old female presented with a hypothalamic hamartoma associated with a dural arteriovenous fistula (DAVF) of the left transverse-sigmoid sinus. She complained of pulsatile tinnitus in the left retroauricular region and infertility. Endocrinological examination revealed that the luteinizing hormone reaction to luteinizing hormone-releasing hormone was exceedingly high. Magnetic resonance imaging demonstrated a distinct mass occupying the suprasellar cistern and protruding into the third ventricle. Left carotid angiography demonstrated a DAVF of the left transverse-sigmoid sinus, which was treated by embolization. Histological examination of a biopsy specimen of the tumor revealed a hamartoma. She was free from pulsatile tinnitus after treatment for the DAVF.

Adult↗

PubMed1997

Orbital varix diagnosed by color Doppler flow imaging--case report.

A 66-year-old male presented with an angiographically occult orbital varix. Angiography and phlebography failed to demonstrate the lesion. Computed tomography angiography showed the varix, but not the vascular flow. Color Doppler flow imaging clearly demonstrated the well-defined varix with slow flow velocity, as well as the precise anatomical location. We recommend color Doppler flow imaging as one of the differential diagnostic tools for intraorbital vascular lesions.

Aged↗

PubMed1997

Recurrent Lhermitte-Duclos disease--case report.

A 43-year-old male presented with recurrent Lhermitte-Duclos disease (LDD), a rare pathological entity of the cerebellum of which the etiology is still controversial. He had undergone subtotal removal of a cerebellar lesion, misdiagnosed as a benign astrocytoma, 8 years previously. Subtotal removal of the recurrent tumor completely resolved the presenting symptoms. Recurrence of LDD is not as rare as generally assumed. Patients with LDD require long-term observation even when the initial treatment appeared curative.

Adult↗

PubMed1997

Mobilization of the internal carotid artery for basilar artery aneurysm surgery. Technical note.

The authors describe a technique for mobilization of the internal carotid artery (ICA) for basilar artery (BA) aneurysm surgery. Using the epidural approach, the anterior clinoid process, orbital roof, and optic canal are drilled away. The ICA is made mobile to the C3 segment by cutting the dural ring and dissecting the ICA from the carotid groove. The ophthalmic artery is then dissected from the optic canal. This mobilization of the ICA secures wide operative fields on both its medial and lateral sides and permits complete clipping of BA aneurysms.

Basilar Artery↗

PubMed1997

Comparison of C1-2 posterior fusion and decompression of the vertebral artery in the treatment of bow hunter's stroke.

Bow hunter's stroke results from vertebrobasilar insufficiency caused by mechanical occlusion or stenosis of the vertebral artery (VA) at the C1-2 level on head rotation. Surgical treatment of this condition may be chosen to avoid life-threatening accidents or because patients complain that conservative treatments such as verbal warnings or use of a neck brace to limit head and neck rotation are ineffective and thus restrict their lifestyle. Posterior fusion involving C1-2 has long been used to limit atlantoaxial rotational movements. However, it has the serious disadvantage that the range of head motion is severely reduced. Recently, decompression of the atlantoaxial portions of the affected VA has been used because it does not limit physiological neck movements. However, no long-term follow-up review of patients who have undergone this procedure has been conducted, and it is unclear whether this procedure always provides relief of symptoms. To answer this question, the results of C1-2 posterior fusion were compared with decompression of the VA for the treatment of bow hunter's stroke.

Aged↗

PubMed1997

[Cerebral infarction due to bacterial emboli associated with methamphetamine abuse].

The number of stimulant-drug addicts has recently been on the rise again, and they are being increasingly encountered in the emergency room. There are also frequent reports of cerebrovascular disorders complicating drug toxicity. These cerebrovascular disorders have included subarachnoid hemorrhage, intracranial hematoma, and a few cases of cerebral infarction. Here, we report the case of a 37-year-old male with drug toxicity, consciousness disorder, and hyperthermia. He was in a coma with a temperature of 43.1 degrees C and blood pressure of 58/35 mmHg when brought to our hospital. His condition worse rapidly deteriorated, and he died the same day. Cerebral infarction caused by gram-positive bacillus embolism, not necrotizing angiitis, was found at autopsy. Because drug addicts, especially stimulant-drug addicts, tend to inject themselves drug under unsanitary conditions, the possibility of this type of complication is always present. This is the first such case ever reported, and is therefore regarded as a rare complication of stimulant-drug intoxication.

Adult↗

PubMed1997

Expansive laminoplasty for multilevel cervical OPLL.

Expansive laminoplasty is a new technique for the management of cervical ossification of the posterior longitudinal ligament (OPLL). Twenty patients were followed up for an average 3-year period. Follow-up examinations were performed every 3 months and at 1-year intervals. On lateral radiographs, the average increase in the anteroposterior (AP) diameter of the canal was 42%. Bone fusion was documented on computed tomography (CT) studies 3 months after surgery in 96% of patients. An average 83% of normal range of motion was preserved on long-term follow-up (3 years on average). Postoperative improvement over the same interval increased from an average preoperative Japanese Orthopaedic Association score of 7.9 to 14.1 Expansive laminoplasty as described is safe and has a high fusion rate, while better preserving the normal range of motion.

Constriction, Pathologic↗

PubMed1997

[Acute subdural hematoma due to pure cortical arterial injury: analysis of 14 cases].

Pure cortical arterial injury is defined as an acute subdural hematoma (ASDH) due to micro laceration of the cortical artery without cerebral contusion. We analyzed this peculiar ASDH in 14 cases. This ASDH has the following characteristics. 1) This disease develops in elderly persons after minor head trauma. 2) After a relatively long lucid interval, the consciousness level of these patients decreases rapidly to semicoma or deep coma. 3) Brain atrophy, atherosclerosis and a tendency to bleed (drugs, hemodialysis, thrombocytopenia, etc.) are involved in this hematoma. 4) The clinical outcome is generally poor because of systemic complications. The authors infer the mechanism of pure cortical arterial injury to be as follows. Minor hemorrhage occurs due to direct impact damage after trivial head trauma, but physiological hemostatic actions are set in motion. After a lucid interval, rebleeding from the injured cortical artery causes massive subdural hemorrhage.

Acute Disease↗