Biomedical subjects

K Hashi

Publications and source records attributed to K Hashi.

At least 73 records · Page 4Linked to original sources

PubMed1994

Immunohistochemical and electron microscopic studies on intracranial chordomas: difference between typical chordomas and chondroid chordomas.

Immunohistochemical and electron microscopic studies were carried out on 9 cases of intracranial chordomas. Three of them were typical chordomas and 6 were chondroid chordomas. Immunohistochemically, both typical chordomas and chondroid chordomas were positively stained for cytokeratin and epithelial membrane antigen. Chondroid chordomas were stained for vimentin with moderate intensity whereas typical chordomas were only slightly stained. In comparison to typical chordomas, the chondroid chordomas had relatively few desmosomes and intermediate filaments. These findings suggest that intracranial chordomas are of mixed epithelial-mesenchymal nature, and that chondroid chordomas have a predominant mesenchymal character as compared to typical chordomas.

Adult↗

PubMed1994

[Superacute changes in blood-brain barrier following cerebral venous hypertension due to an embolic occlusion of cerebral venous sinus].

Pathophysiological mechanism of hemorrhagic infarction and brain edema following obliteration of venous outflow tract has been poorly understood. We analyzed a superacute change of the blood-brain barrier in a rat experimental model of venous hypertension produced by an embolic occlusion of superior sagittal sinus (SSS). In all thirty-seven animals received retrograde embolization, marked increments of SSS pressure were noted immediately after embolic occlusion of the sinus. Severity and geographical patterns of the disruption of blood-brain barrier were then analyzed photomicrographically, visualized by the autofluorescence of the exuded Evans blue with Hematoxylin-eosin stain. Relationship between the degree of SSS pressure increment and the severity of the blood-brain barrier destruction was studied. In ten out of the seventeen animals (59%), analyzed five minutes after embolization, exudation of the dye was demonstrated. The degree of SSS pressure increment in the animals with dye exudation was higher than in the animals without them. In five out of the nine animals (56%), analyzed fifteen minutes after embolization, exudation of the dye was also demonstrated. The degree of SSS pressure increments in the animals with dye exudation was statistically higher than those in the non-exuded ones. Especially, all the animals with SSS pressure higher than 75 mmHg were associated with severe exudation of the dye. The exudation of the dye was more prominent in the white matter than in the cortical gray matter. Following pathological analysis have revealed that exudation of the dye was most prominent around the capillary and the venule in the white matter. Microvacuolation around these vessels was also noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1994

Photoaffinity labeling of lipoproteins in human cerebrospinal fluid with a heterobifunctional derivative of galactosylsphingosine.

The binding of a galactosylceramide (GalCer) analog to proteins in normal human cerebrospinal fluid (CSF) was examined by photo-affinity labeling using a radioiodolabeled 2-(p-azido-salicylamido) ethyl-1,3-dithiopropionate (ASD) derivative of galactosylsphingosine (GalSph) as a probe. The affinity-bound peptides appeared at 66, 36 and 28 kDa as radiolabeled bands. The latter two peptides, 36 and 28 kDa, were independently identified by immunostaining of the isolated peptides using biotinylated GalSph, and immobilized Avidin, and by immunoprecipitation of the photolabeled peptide, to apolipoproteins (ALPs) E and A-I, respectively. The direct binding of the GalCer analog to these apo-peptides suggested that the existence in the body fluids or the transfer between the fluids and cells of the glycolipid was related to high density lipoprotein (HDL) constructions.

Affinity Labels↗

PubMed1994

[Clinical analysis of the fatal cases of adult malignant gliomas after aggressive treatment].

Six patients operated on for supratentorial malignant astrocytomas and seven patients operated on for glioblastoma multiforme were analyzed to evaluate the effect of aggressive surgical resection on the length of survival and causes of death. Early postoperative contrast enhanced CT scan was used to assess the extent of surgical resection. A gross total resection was considered to have been accomplished when there was no evidence of any residual enhanced mass. When 10% or less of the preoperative enhanced mass remained, the resection was classified as a subtotal resection. Subsequent follow-up CT scan showed that a gross total resection was accomplished in nine patients, and a subtotal resection was attained in four patients. The patients' ages ranged from 40 to 78 years (mean, 59 years). The median survival after the first aggressive surgical resection was 18.0 months in patients with malignant astrocytoma and 13.6 months in those with glioblastoma multiforme. The median duration between first operation and recurrence of tumor was 8.8 months in patients with malignant astrocytoma and 11.5 months in those with glioblastoma multiforme. A second aggressive surgical resection for recurrent malignant astrocytoma or glioblastoma multiforme was carried out in four patients (40%) of the evaluated ten patients. The median survival of these patients after reoperation was 8.25 months. Accordingly, aggressive surgical resection of malignant astrocytoma and glioblastoma multiforme is correlated with longer survival and is advocated in the treatment of recurrent tumors. Leptomeningeal dissemination was diagnosed in nine patients (90%) of evaluated ten patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

[Percutaneous transluminal angioplasty for progressing stroke caused by severe basilar artery stenosis: case report].

We encountered one case of progressing stroke caused by severe basilar artery stenosis. The patient was treated with emergent percutaneous transluminal angioplasty (PTA) with satisfactory results. A 54 year-old woman was admitted 15 minutes after the sudden onset of rt. hemiparesis, rt. hemidysesthesia, dysarthria and consciousness disturbance. CT scan on admission showed no abnormal findings. The consciousness level of the patient deteriorated rapidly from JCS 1 to JCS 20 within 30 minutes from the ictus. An emergent angiogram revealed severe basilar artery stenosis at its middle portion and poorly developed collateral circulation. One hour after the stroke occurred, PTA was performed. Using a 3mm diameter balloon catheter, we introduced the balloon into the stenotic lesion and inflated it 6 times from 4 atm to 8 atm pressure. The patient recovered immediately on the operating table improving from JCS 20 to JCS 1. Rt. hemiparesis also improved. Follow-up MRI showed a small area of ischemic change in the brain stem, but no large infarction appeared. The patient was discharged with no neurosurgical deficits after 30 days of PTA. PTA for basilar artery stenosis is still a controversial subject. One reason is the risk of basilar artery perforating branches occlusion by balloon catheter and the other is the difficulty of introducing a flexible balloon catheter into the basilar artery beyond the acute angulation of the vertebral artery. If those two problems were solved, PTA would be the first-choice therapy for basilar artery stenosis in both acute and chronic stages.

Acute Disease↗

PubMed1994

[Cerebellar infarcts that require differentiation from tumors: diagnosis with MRI].

It is often difficult to differentiate cerebellar infarct with cerebellar swelling from neoplastic disorders, because former can be shown as cerebellar mass with marked contrast enhancement on CT scan. We analyzed radiologically three cases with cerebellar infarction by using MRI, conventional CT scan and angiography. Two cases in the acute stage could be diagnosed as cerebellar infarction by MRI alone based on the following findings: 1) the lesion was distributed in the territory of cerebellar arteries; 2) the normal pattern of cerebellar folia and fissures was preserved in Gd enhancement MRI image; 3) characteristics of MRI intensity were compatible with hemorrhagic infarction. The other case in the chronic stage showed peculiar enhancement, which was unusual for infarction. It was diagnosed as cellular infarction with reference to the angiographic findings. MRI is generally useful to obtain early diagnosis of tumor-like cerebellar infarcts, and proper treatment should be started as early as possible.

Aged↗

PubMed1994

[A case of dural type of histiocytosis X presenting as a mass lesion in the tentorium cerebelli].

Histiocytosis X is a disease of unknown etiology, characterized by a mass of proliferating histiocytes, plasma cells and inflammatory cells foaming a granuloma within the reticuloendothelial elements of any organ in the body. In the central nervous system (CNS), hypothalamic disorder of histiocytosis X is often found, but histiocytosis X in other regions is quite rare. We report a case of a 5-year-old girl with histiocytosis X of the zygoma presenting as a mass lesion in the tentorium cerebelli. A computed tomographic (CT) scan demonstrated a tumor at the left tentorial region, extending along the dura mater of the tentorium cerebelli. Magnetic resonance imaging (MRI) revealed a low signal intensity region on both T1 and T2-weighted images. MRI with Gd-DTPA showed a homogeneous enhanced mass extending to right and inferior sites with a thickened tentorium. As the thickened dura matter continued from the left middle fossa to the mass lesion, the tumor was considered to arise from the left zygoma and extend to the tentorium cerebelli. CNS extension of histiocytosis X is manifested either as (1) the cerebral type or (2) the dural type. Many cases of cerebral type histiocytosis X including hypothalamic disorder have been reported. Only 6 cases of the dural type of histiocytosis X have been described. Although the lesions of the cerebral type of histiocytosis X show prolonged T1 and T2 values on MRI, the MRI findings of the dural type have not been reported. The present case is the first report of the appearance of the lesion on MRI.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebellar Diseases↗

PubMed1994

[Technical tactics to preserve cortical venous drainage in interhemispheric approach for anterior communicating artery aneurysms].

The interhemispheric approach has been selected for clipping of the anterior communicating artery aneurysm located high above the sphenoidal plate, and in a posterior direction. However, this approach is sometimes complicated with postoperative hemorrhagic infarction due to excess brain retraction combined with damages of the cortical bridging veins. We have devised a modification in this approach to eliminate these complications. Our newly devised methods include the following; 1) Small bifrontal craniotomy performed, 2) Continuous ventricular drainage performed to minimize the effect of compression by the spatula during resection of interhemispheric fissure, 3) Bifrontal dural incision made along the frontal skull base, 4) Mobilization of the major cortical vein in the operated field, if necessary, by resection of the overlying arachnoid membrane with or without sacrificing its small tributaries, 5) Gradual dissection of the olfactory nerves according to the process of operation. We analysed the incidence of operative complications in thirteen consecutive cases with this approach. Major frontal ascending veins were carefully preserved in all cases. None showed hemorrhagic infarction, regardless of the cortical venous drainage patterns. The degree of smell preserved in 10% of the examined 11 cases was more than unilateral. In conclusion, this method is useful for the elimination of perioperative complications even in the acute stage of subarachnoid hemorrhage.

Adult↗

PubMed1993

Human blood group B-active ganglio-glycosphingolipid in rat glioma.

A human blood group B-active glycosphingolipid, belonging to the ganglio-series, was isolated from rat glioma cell line RG2 subcutaneous isografts. The oligosaccharide structure of the glycosphingolipid was completely characterized as Gal alpha 1-3(Fuc alpha 1-2)Gal beta 1-3GalNAc beta 1-4Gal beta 1-4Glc beta 1- 1'ceramide by NMR spectrometry, negative fast atom bombardment-mass spectrometry, sequential degradation by glycosidases and methylation analysis. Human blood group B antigenicity and the activity of this glycosphingolipid were confirmed by immunostaining on thin-layer chromatography and the inhibition of hemagglutination, respectively. Although the lipid has been detected in rat granuloma, bone marrow cells, spleen, thymus, ascites hepatoma cells and gastric mucosa, this is the first report of the occurrence of the B-active lipid in glioma.

ABO Blood-Group System↗

PubMed1993

Effect of local administration of lymphokine-activated killer cells and interleukin-2 on malignant brain tumor patients.

Nine patients with malignant brain tumors were treated with intratumoral infusion of lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2). LAK cells were generated from macrophage-depleted peripheral blood lymphocytes by culturing with IL-2 for 4 days. The resulting LAK cells showed strong cytotoxic activity against tumor target cells. Three patients received sufficient LAK cells (> or = 5.76 x 10(8)) to show partial tumor response by computed tomography and clinical signs. No severe neurological side effects occurred in any patient. Intratumoral administration of LAK cells and IL-2 can be effective in patients with malignant brain tumors.

Adult↗

PubMed1992

Results of reoperation for failed microvascular decompression.

Among 64 patients with hemifacial spasm (HFS) and 60 with trigeminal neuralgia (TN) treated by microvascular decompression (MVD), repeated MVD performed on 3 cases with HFS resulted in the absence of spasm in all cases. In 7 cases with TN, this technique resulted in complete remission in 2, recurrence in 3, and no pain relief in 2 cases. MVD was more effective on HFS than on TN in repeated procedures as well as for initial treatment. The cause of recurrence of HFS was attributed to the inadequate cushion effect of muscle as a prosthesis, while that for TN was suspected to be related more to post-operative fibrotic adhesions formed around the fifth nerve.

Adult↗

PubMed1992

Cerebral salt wasting syndrome distinct from the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

Two cases with pituitary tumour developed postoperative hyponatraemia which was not caused by inappropriate secretion of antidiuretic hormone. The one case with non-functioning macro-adenoma showed severe hyponatraemia (116 mEq/l) on day 11 after trans-sphenoidal surgery in association with diabetes insipidus (DI). The patients was treated by aqueous pitressin and saline administration to control urinary output and keep positive salt balance at the same time. The other case with GH-producing macro-adenoma showed progressive negative sodium balance with the total loss of 644 mEq resulting in hyponatraemia of 133 mEq/l. This was corrected by additional salt intake. The plasma atrial natriuretic polypeptide (ANP), antidiuretic hormone (ADH) as well as aldosterone levels were normal in the latter case. These patients were considered to manifest primary salt wasting disorder, which should be clearly differentiated from the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

Adenoma↗

PubMed1992

[Functional results of preservation of cranial nerves in removal of acoustic neurinoma].

Seventeen patients with acoustic neurinoma were reviewed on the basis of postoperative preservation of facial and acoustic nerve functions. The sizes of tumors were intracanalicular in 5 cases, smaller than 20mm in diameter in 2 cases, smaller than 30mm in 5 cases, and larger than 30mm in 5 cases. In all cases, the facial nerve was anatomically preserved at operation. Functional recoveries of the facial nerve in follow-up were excellent in 7 cases out of 17 (41%), good in 5 (29%) and poor in 5 (29%). Although the functional preservation for the facial nerve was related to the size of the tumor, it was favorable in cases of cystic tumor even with a size larger than 20mm. By pure tone audiogram, hearing was found to be preserved in 12 cases before operation. At operation, the acoustic nerve was anatomically preserved in 4 cases. Postoperative hearing was maintained in two cases, one of which showed a successful preservation of serviceable hearing. In this case, tumor resection was performed with intraoperative monitoring of auditory brain stem reactions (ABRs). Discussion was made concerning a possible surgical candidates for the hearing preservation, and it was proposed that every effort should be made to preserve the cochlear nerve if following conditions were verified in the case: 1) normal or nearly normal hearing (less than 40-50dB hearing loss), 2) the size of tumor is intracanalicular or smaller than 2cm in diameter, 3) there is no deterioration of intraoperative ABR.

Adult↗

PubMed1991

Vascularized omentum graft for the reconstruction of the skull base after removal of a nasoethmoidal tumor with intracranial extension: case report.

A 16-year-old boy with rhabdomyosarcoma occupying the nasal cavities and the ethmoid sinus with intracranial extension underwent transcranial surgery. The intradural tumor was resected first with the affected dura of the anterior skull base, and the dural defect was repaired with fascia harvested from the sheath of the rectus abdominis muscle. The remaining tumor contiguous to the nasal cavities was completely extirpated. The cranial cavity was then exposed to the opened nasal cavities, where a revascularized omental graft was used to separate these compartments. Lyophilized dura was placed beforehand beneath the omental graft, as a roof to the nasal cavity, and was removed 3 weeks later through the nostril. A bony skull base repair was performed over the omentum using the inner table of the bone flap. Subcutaneous fat from the abdomen was placed on the bone graft for fixation and as an additional seal for the dural defect. Reconstruction of the anterior skull base with a vascularized omental transfer provides an efficient barrier to the nasal cavity. It also serves as an excellent supporting structure for regeneration of the mucosal epithelium of the nasal cavities.

Adolescent↗

PubMed1991

[A basic study on omental transplantation. Vascular endothelial cell growth factor in human omentum].

Omentum tissue has potent angiogenic activity, so transplantation is often effective in treatment of moyamoya disease. Omentum was homogenized and fractionated to investigate the presence of an endothelial cell growth factor. The effectiveness of extracts was measured by the growth activity of bovine aortic endothelial cell incubated for 6 days with various omentum extracts. The lipid fraction had no growth promoting activity. However, the water soluble extracts were active. The activity could be increased by ammonium sulfate precipitation (60-80% saturation). Gel permeation chromatography of the ammonium sulfate fraction showed that the endothelial growth factor had an apparent molecular weight of 96,000. Heparin affinity chromatography revealed poor heparin affinity. The activity was stable at pH 3.5 and pH 9.5, but inactivated by heating at 70 degrees C for 10 minutes or 100 degrees C for 2 minutes. These properties clearly distinguish the omentum-derived growth factor (OmDGF) from the heparin binding growth factor. OmDGF is probably distinct from other vascular endothelial cell growth factors.

Animals↗

PubMed1991

[Cavernous malformation of the brain stem: clinical symptom and its surgical indication].

Clinical features and surgical indication of cavernous malformation (CVM) of the brain stem are reviewed, based on the analysis of five personally encountered cases and nineteen previously reported cases. Nineteen out of these twenty four cases presented sudden onset of neurological deficits suggesting brain stem hemorrhage. Although the majority of those patients with acute onset improved gradually within a couple of weeks, all cases, except for six cases treated with radical removal following their first bleeding episodes, presented recurrent hemorrhages, and one third of them died due to the repeated hemorrhages. The other six cases presented progressive neurological deficits with insidious onset. They were first diagnosed as brain stem gliomas or multiple sclerosis. All except two cases treated with radical removal of the CVM died within a year. Surgical indication of the cerebral CVM is still controversial, because its clinical presentations and natural history have been unclear. Recent clinical application of magnetic resonance imaging enables us not only to make a preoperative diagnosis accurately, but also to evaluate the operability in relation to its anatomical location. Because of an apparent disposition towards repeated hemorrhages, surgical removal should be considered for the symptomatic CVM in the brain stem, on which microsurgical manipulation would be possible with an acceptable risk in many cases.

Adult↗

PubMed1990

Non-heparin-binding endothelial cell growth factor from bovine omentum.

The graft of omental pedicle is known to be clinically effective for wound healing and revascularization of ischemic organs. We found that bovine greater omentum contained growth factor that was capable of stimulating the proliferation of bovine aortic endothelial cells. Gel filtration of the tissue extract showed at least two activity peaks corresponding to molecular weights of 96,000 and 21,000. The major Mr 21,000 growth factor was partially purified approx 120-fold from the omental extract. The purified factor was not mitogenic to BALB/c 3T3 cells and, importantly, had no affinity for immobilized heparin. This factor is thus clearly distinct from fibroblast growth factors and related mitogens. The pI of the factor was estimated to be 5.6-6.0. This factor may be involved in the potent angiogenic activity expressed by the implanted omentum. The omental fat, which was previously shown to cause neovascularization in the assay in vivo, did not promote the growth of endothelial cells in vitro.

Animals↗

PubMed1990

Regional ischemia in cerebral venous hypertension due to embolic occlusion of the superior sagittal sinus in the rat.

To determine the pathophysiological changes in brain tissue that characterize damage following cerebral venous hypertension, a model of cerebral venous hypertension in the rat was devised. This experimental model has the advantage of simultaneously measuring the regional changes in cerebral blood flow as well as the metabolism. The ischemic area demonstrated by the accumulation of NADH is confined to the cerebral cortex and becomes enlarged in proportion to the increase in venous pressure. This metabolic disturbance appears even in the very early period following cerebral venous hypertension. These pathophysiological features are different from those observed in the case of intracranial hypertension.

Animals↗