Search PubMed⌕ Search

Biomedical subjects

T Itakura

Publications and source records attributed to T Itakura.

At least 127 records · Page 7Linked to original sources
PubMed1993

Cytokeratin immunohistochemical study of epithelial cysts in the central nervous system: with special reference to origins of colloid cyst of the third ventricle and Rathke's cleft cyst in the sella.

A variety of epithelial cysts in the central nervous system were examined immunohistochemically for expression of cytokeratins. Colloid cysts, Rathke's cleft cysts and epithelial cysts in the spinal canal expressed complex type cytokeratins, while enterogenous cysts and neuroectodermal cysts showed only simple type cytokeratins. Colloid cysts showed a pattern of cytokeratins similar to that of upper respiratory tract which is endodermal in origin. In contrast, Rathke's cleft cysts showed a pattern of cytokeratins similar to that of the adenohypophysis and salivary gland which are ectodermal in origin. The CK immunohistochemical studies are discussed with regards to diagnostic significance and origins of their cysts.

Adult↗
PubMed1993

[A case of epidural hematoma caused by a vacuum extraction without any skull fractures and accompanied by cephalohematoma].

A case of epidural hematoma associated with cephalohematoma caused by a vacuum extraction was reported. Old liquefied hematoma was removed via a small burr hole in the parietal bone at the age of 23 days. No neurological deficits were recognized at the age of 6 months. As the dura mater does not easily detach from the overlying skull in the neonate, it is a very rare occurrence for this to happen as a complication of the use of forceps or in extractions. To our knowledge, only 4 cases of epidural hematoma after vacuum extraction have been reported. The mechanism of the development of an acute epidural hematoma during extraction is reported to be due to direct force to the dura mater and skull induced by negative pressure of a vacuum extraction. In the present case, it seems that negative pressure produced a detachment of the dura mater from the overlying skull. It suggests that examinations including plain craniogram and CT scan should be performed as soon as possible in the neonate with cephalohematoma when they have been delivered by a vacuum extraction.

Bone Diseases↗
PubMed1993

[Newly developed blocking balloon catheter for PTA of internal carotid artery].

We have developed a new blocking balloon system for percutaneous transluminal angioplasty (PTA) of the internal carotid artery (ICA). A latex balloon (BALT) is attached on the top of a Superselector infusion-type catheter (TORAY) which is used as a blocking balloon catheter. It can be navigated into the distal part of the ICA under torque control as well as flow control by withdrawing the core wire. Our PTA procedure is as follows, 1) insert the sheath catheter 8-9 F in size, 2) insert the PTA balloon catheter (Accent balloon, Cook) with a blocking balloon catheter through the sheath catheter, 3) navigate the blocking balloon into the distal part of the ICA, 4) introduce the PTA balloon to the stenotic portion after occlusion of the distal ICA by the blocking balloon, 5) PTA, 6) wash the lumen of the ICA with saline, 7) deflate the blocking balloon and withdraw the system. We performed PTA for 5 ICA lesions in 4 cases and got successful dilatations for all of them without complications. Our blocking balloon system is useful for performing the PTA of the ICA safely.

Aged↗
PubMed1992

The recurrence of primary intracranial germinomas. Special reference to germinoma with STGC (syncytiotrophoblastic giant cell).

Twenty three cases of primary intracranial germinomas including five cases of germinomas with syncytiotrophoblastic giant cells are studied and analyzed, with special reference to the recurrence under radiotherapy. The follow-up period for all cases was 7 months to 12 years (average: 5.8 years) with that for pure germinomas ranging from 8 months to 12 years (average: 5.7 years) and that for germinomas with syncytiotrophoblastic giant cells ranging from 7 months to 11 years (average: 6.3 years). Late recurrence was observed in three cases (3/23, 13%), developing outside of the initial irradiation field. With regard to recurrence, significant correlation to radiation fields was evident, while it was not to radiation doses. Furthermore, germinoma with syncytiotrophoblastic giant cells showed a more significant tendency to recur than pure germinoma. The radiotherapy of germinomas is discussed and the clinical features of germinoma with syncytiotrophoblastic giant cells are presented.

Adolescent↗
PubMed1992

A method for quantitative measurement of cerebral vascular permeability using X-ray CT and iodinated contrast medium.

Cerebral vascular permeability is an important consideration in treatment for intracranial tumours. We have developed a new method to measure the cerebral vascular permeability quantitatively using a conventional X-ray CT scanner and iodinated contrast medium. We have already applied our method in 50 cases of intracranial tumour and 5 cases, which establish the methodology, are demonstrated. Dynamic CT scanning of a section including the tumour and the superior sagittal sinus was performed over 40 min after bolus injection of contrast medium, and 25 images were acquired. Our theoretical model of contrast enhancement was applied to analyse time-density curves, and the following parameters were obtained: Ki (inward flux constant), Kb (backward flux constant), Vp (vascular plasma volume), and lambda (extracellular fluid space volume). Furthermore, functional maps were generated from parameters for each pixel. Changes in intra-arterial iodine concentration, required in our model, were measured from CT numbers in the superior sagittal sinus. We have investigated several aspects of our method. Histological findings in surgical specimens of intracranial tumours agreed well with the parameters obtained by our method. Vp was verified quantitatively by single photon emission computed tomography. Our method was shown to be reproducible. These results show that the parameters are useful for assessing tumours and in planning chemotherapy. Our method, which employs no special equipment, is readily available at any institution.

Adult↗
PubMed1992

Local blood flow changes in malignant brain tumours under induced hypertension.

Changes in tumour blood flow under an induced hypertensive state were examined in malignant brain tumours to know if the precondition for the effectiveness of induced hypertensive chemotherapy--relative increase in tumour blood flow--are fulfilled. Tumour blood flow was measured under both a resting and an induced hypertensive state in 12 patients with various malignant brain tumours (6 gliomas, 6 metastatic brain tumours) using xenon-enhanced computed tomography. The blood pressure was elevated 40% above the systemic blood pressure of the resting state by the infusion of angiotensin II. Tumour blood flow increased 30% on average above the normal brain tissue blood flow after the induction of an induced hypertensive state (p < 0.05). The tumour blood flow increased in 11 cases of malignant tumours, but decreased in one case with massive brain oedema after induced hypertension. The increase in blood flow was higher in hypervascular tumours and less in hypovascular tumours. Therefore, induced hypertensive chemotherapy probably will be more effective in hypervascular malignant brain tumours with small mass effects.

Adult↗
PubMed1992

Autotransplantation of peripheral cholinergic neurons into the brains of Alzheimer model rats.

Current hypotheses regarding Alzheimer's disease implicate cholinergic function. In this study, peripheral cholinergic neurons in the vagal nodosal ganglion were transplanted into the brains of Alzheimer model rats. Eighteen Sprague-Dawley strain rats were divided into three groups: 1) unoperated control rats, 2) rats that had undergone bilateral destruction of the nucleus basalis of Meynert (NBM) (Alzheimer model), and 3) the transplantation group in which the vagal nodosal ganglion was transplanted into the cerebral neocortex one week after the bilateral destruction of the Meynert nucleus. Seven weeks after the transplantation rat behaviour was assessed using psychological tests (spontaneous activity, passive avoidance response and the Hebb-Williams maze test). The Alzheimer model rats had a statistically significant increase in spontaneous activity in comparison with controls (P less than 0.01). The transplant rats showed some amelioration of this abnormal increase in spontaneous activity observed in the Alzheimer model rats. All of the control rats showed conditioned passive avoidance responses, while only one Alzheimer model rat retained is shocked-conditions behaviour before 24 hours (P less than 0.01). Three of the six transplanted rats showed complete improvement in the passive avoidance response test. In the Hebb-Williams maze test, the rats with NMB lesions made more errors than the control rats. The transplanted rats had a lower number of errors than NBM-lesioned rats but still more than the controls. Histological examination revealed many cholinergic cells in the transplanted tissue, especially in the area adjacent to the cerebral cortical surface. The present results indicate that autotransplantation of peripheral cholinergic cells ameliorates abnormal behaviour in Alzheimer model rats.

Alzheimer Disease↗
PubMed1992

A possible involvement of central atrial natriuretic peptide in cerebral cortical microcirculation.

The possible involvement of atrial natriuretic peptide (ANP) in cerebral cortical microcirculation was investigated in rats by means of laser-Doppler flowmetry and immunohistochemistry. In the laser-Doppler study, local cerebral blood flow (LCBF) changes after the administration of 10(-6) to 10(-8) mol/LANP solution or vehicle (saline solution) as an intracortical injection for 5 minutes were continuously monitored throughout the 30 minutes of the study and were expressed as percentages of preinjection values represented as 0%. The administration of 10(-6) to 10(-8) mol/LANP caused a significant decrease in LCBF; the onset of LCBF responses occurred within a few minutes after the start of the injection and the decrease in LCBF reached the maximum level within 7 to 10 minutes after the completion of the administration, after which LCBF gradually recovered. In the immunohistochemical study, no specific ANP immunoreactivity was found associated with the intraparenchymal blood vessels; however, ANP-immunoreactive neurons were observed primarily in the hypothalamus and septum, in which high concentrations of ANP-containing neurons have been identified. The data from the laser-Doppler study suggest that central ANP may produce a vasoconstriction of the intraparenchymal blood vessels, regardless of whether through direct action on these vessels or through the mediation by some system in the central nervous system. Because there is no evidence for ANP-containing nerves around these vessels, the role of central ANP in the cerebral circulation must await identification of the source of perivascular ANP.

Animals↗
PubMed1992

Meningeal melanocytoma: magnetic resonance imaging characteristics and pathological features. Case report.

A case of meningeal melanocytoma at the foramen magnum is reported in a 62-year-old man. Magnetic resonance (MR) imaging revealed characteristic signal patterns: homogeneous high intensity on the T1-weighted image and low intensity on the T2-weighted image. Light microscopy showed a histological appearance similar to that of melanotic meningioma. The ultrastructural features of the neoplastic cells were compatible with those of melanocytes, but they contained no features of arachnoidal cells. Immunohistochemical bromodeoxyuridine study revealed low proliferative activity among the neoplastic cells. The MR appearance and pathological features in this rare case of meningeal melanocytoma are demonstrated and discussed.

Humans↗
PubMed1992

Bilateral morning glory syndrome associated with sphenoid encephalocele. Case report.

Morning glory syndrome is a congenital anomaly of the optic disc in which the disc is enlarged and excavated, with white glial tissue in the center. A case is presented of morning glory syndrome associated with sphenoid encephalocele, median cleft lip, and agenesis of the corpus callosum. A 22-day-old boy was referred to the Wakayama Medical College Hospital for management of dyspnea due to a soft-tissue mass in the oral cavity. Magnetic resonance imaging revealed a mass extending through a bone defect in the sphenoid region and into the oral cavity. Surgical repair was attempted through a bifrontal craniotomy. A bone defect was identified in the sphenoid plate, through which the arachnoid membrane was connected to the oral cavity. Both optic nerves were elongated and adhered to the encephalocele. The wall of the meningocele was compressed digitally through the oral cavity and sutured to the dura mater of the bone defect. The operative findings suggest that a basal encephalocele protruding from a bone defect in the sphenoid plate may disturb the normal development of the optic nerve.

Abnormalities, Multiple↗
PubMed1992

[Pitfalls of endovascular treatment for cerebral aneurysms].

Seventeen cases of unclippable aneurysms were treated by the endovascular balloon technique. Nine of them involved the anterior circulation, and eight involved the posterior circulation. Eleven of them were treated by parent artery occlusion with detachable balloons. Three were treated by endosaccular balloon embolization, and three cases combined with AVMs were occluded using ethylene vinyl alcohol copolymer (EVAL) including feeding arteries of the AVMs. Embolic complications occurred in one case of an IC bifurcation giant aneurysm treated by parent artery occlusion. Ischemic complications also appeared in two cases of aneurysms treated by endosaccular balloon embolization. In one case, the thrombus in the aneurysm propagated into the parent artery and occluded it later. In another case, the displaced balloon had obliterated the parent artery 6 hours after the embolization. Parent artery occlusion is a safe way to treat internal carotid giant aneurysms. However, endosaccular treatment still has some problems, i.e., 1) maintaining the balloon's position to preserve the parent artery, 2) balloon migration into the clot, 3) rupture of the aneurysm during or after treatment. Our studies indicate that endosaccular balloon embolization is still a high risk procedure and should be used only in selected cases, until new embolic agents, such as detachable coils, become available.

Adult↗
PubMed1991

Ruptured cerebral aneurysm successfully clipped in idiopathic thrombocytopenic purpura after high-dose gamma-globulin therapy--case report.

A ruptured cerebral aneurysm in a 50-year-old female with idiopathic thrombocytopenic purpura was successfully clipped after preoperative high-dose gamma-globulin therapy to control the hemorrhagic diathesis. High-dose gamma-globulin therapy with or without steroid and/or platelet transfusion is recommended for such cases if the blood pressure can be controlled and the neurological condition permits delayed surgery.

Blood Loss, Surgical↗
PubMed1991

[Acute subdural empyema due to peptostreptococcus].

A very rare case of acute subdural empyema due to peptostreptococcus was reported. A 11-year-old-girl was admitted to our hospital with high grade fever, unconsciousness and rt hemiparesis. CT scans showed the mass effect caused by the subdural empyema over the left frontotemporal region. Subdural empyema was evacuated by the craniotomy. Peptostreptococcus was found in the pus obtained during the operation. However, CT scans 10 days after the operation revealed another subdural empyema in the left frontal base and interhemispheric fissure, which was removed again by the craniotomy using coronal incision 14 days after the first operation. Frontal sinusitis was also demonstrated by CT scan. Killian's operation to the frontal sinusitis was performed by otorhinolaryngologists at the same time. Six weeks after the second operation, she was discharged without any neurological deficits. Peptostreptococcus is one of the indigenous microflora of the oral cavity, skin, gastrointestinal tract and genitourinary system and may be a causative microorganism in every type of human infection due to its abnormal localization. There is a controversy concerning surgical management subdural empyema. Both the burr hole drainage of pus and the craniotomy are advocated. Associated otorhinologic lesions must not be overlooked. Otorhinologic consultation should immediately be obtained so that the drainage of an infected paranasal or mastoid sinus can be performed at the time of craniotomy. This is critical to prevent the recurrence of the subdural empyema from further extension of the extracranial disease.

Acute Disease↗
PubMed1991

[Selective vulnerability of peptide-containing neurons in cerebral ischemia; immunohistochemical study].

Histochemical changes in peptidergic and catecholaminergic neurons during ischemia were investigated in the cerebral neocortex of the gerbil. Catecholaminergic fibers were observed by catecholamine histofluorescence with glyoxylic acid solution, and peptidergic neuron systems such as vasoactive intestinal polypeptide (VIP), somatostatin (SOM), and neuropeptide Y (NPY) were observed by immunohistochemistry. Two hours after unilateral occlusion of the internal carotid artery, catecholaminergic fibers disappeared in the neocortex on the occlusion side, while peptidergic nerve fibers except for NPY fibers were intact after 2 hours of ischemia. NPY fibers had decreased in number on the occlusion side 2 hours after ischemia. VIP-, SOM-, and NPY-immunoreactive neurons showed a decrease of 60% six hours after ischemia, and these neurons completely disappeared in the cerebral neocortex 24 hours after ischemia. These results suggest that catecholaminergic neuron system is more vulnerable than the peptidergic one in ischemic event.

Animals↗