Biomedical subjects

Hiroyuki Kinouchi

Publications and source records attributed to Hiroyuki Kinouchi.

28 records · Page 2Linked to original sources

PubMed2003

[A case of metastatic suprasellar tumor with edema along the optic pathway].

A rare case in presented of a patient with edema formation along the optic pathway, which was caused by metastatic suprasellar tumor mimicking craniopharyngioma. A 63-year-old female with visual disturbance, diabetes insipidus, and symptomatic panhypopituitarism was admitted to our hospital. CT images showed a suprasellar mass lesion. MR images demonstrated a heterogeneously enhanced tumor and edema along the optic nerve and tract. Although no cystic component is shown in radiological findings, these features are commonly observed in cases of craniopharyngioma. The patient underwent removal of the tumor by the transcranial approach. Since histological examination revealed adenocarcinoma, the tumor was diagnosed as metastatic brain tumor originating from non-recurrent rectal cancer operated on eight years previously. Conventional radiotherapy with a dose of 50GY was performed for the residual tumor. The tumor size was unchanged, but the edema had disappeared 7 months after the operation. Edema spreading along the optic tract was reported as a characteristic MR finding for diagnosis of craniopharyngiomas as distinguished from other common parasellar tumors. However, it is suggested that edema of the optic pathway seems to be caused not only by craniopharyngioma but also other suprasellar lesions. Even if there was a characteristic radiological finding for some specific diseases, metastasis should be kept in mind as a differential diagnosis, because of its various appearance in neuroimages.

Adenocarcinoma↗

PubMed2002

Characterization of the 105-kDa molecular chaperone. Identification, biochemical properties, and localization.

We have characterized the biochemical properties of the testis and brain-specific 105-kDa protein which is cross-reacted with an anti-bovine HSP90 antibody. The protein was induced in germ cells by heat stress, resulting in a protein which is one of the heat shock proteins [Kumagai, J., Fukuda, J., Kodama, H., Murata, M., Kawamura, K., Itoh, H. & Tanaka, T. (2000) Eur. J. Biochem.267, 3073-3078]. In the present study, we characterized the biochemical properties of the protein. The 105-kDa protein inhibited the aggregation of citrate synthase as a molecular chaperone in vitro. ATP/MgCl2 has a slight influence of the suppression of the citrate synthase aggregation by the 105-kDa protein. The protein possessed chaperone activity. The protein was able to bind to ATP-Sepharose like the other molecular chaperone HSP70. A partial amino-acid sequence (24 amino-acid residues) of the protein was determined and coincided with those of the mouse testis- and brain-specific APG-1 and osmotic stress protein 94 (OSP94). The 105-kDa protein was detected only in the medulla of the rat kidney sections similar to OSP94 upon immunoblotting. The purified 105-kDa protein was cross-reacted with an antibody against APG-1. These results suggested that APG-1 and OSP94 are both identical to the 105-kDa protein. There were highly homologous regions between the 105-kDa protein/APG-1/OSP94 and HSP90. The region of HSP90 was also an immunoreactive site. An anti-bovine HSP90 antibody may cross-react with the 105-kDa protein similar to HSP90 in the rat testis and brain. We have investigated the localization and developmental induction of the protein in the rat brain. In the immunohistochemical analysis, the protein was mainly detected in the cytoplasm of the nerve and glial cells of the rat brain. Although the 105-kDa protein was localized in all rat brain segments, the expression pattern was fast in the cerebral cortex and hippocampus and slow in the cerebellum.

Adenosine Triphosphate↗

PubMed2002

Combined embolization and microsurgery for cerebral arteriovenous malformation.

Thirty-seven of 396 patients with arteriovenous malformations (AVMs) were treated by preoperative embolization and surgical excision in our medical center between 1991 and 1997. The AVMs were Spetzler-Martin grade I in six, grade II in 11, grade III in 12, grade IV in four, and Grade V in four. A total of 69 embolization procedures were performed using estrogen alcohol and polyvinyl acetate as liquid embolization materials. AVM grades improved following embolization in 10 patients. Three hemorrhages occurred several days after the final embolization, probably due to hemodynamic stress on the unoccluded perforating feeders or drainer occlusion. Surgical resection was performed under guidance of intraoperative digital subtraction angiography. Although the AVMs were excised totally in one stage with no major neurological deficits, normal perfusion pressure breakthrough occurred in a patient with prominent collateral circulation of the AVM which developed after the main feeder embolization. Preoperative staged embolization with estrogen alcohol and polyvinyl acetate is effective to expand the surgical indication and to achieve complete resection of difficult AVMs. Direct surgery should be performed as soon as possible if hemodynamic changes are observed following embolization.

Adolescent↗

PubMed2002

Endoscope-assisted clipping of a superior hypophyseal artery aneurysm without removal of the anterior clinoid process. Case report.

A 47-year-old man presented with a superior hypophyseal artery aneurysm and an ipsilateral posterior communicating artery aneurysm. Both lesions were successfully clipped without removal of the anterior clinoid process or retraction of the optic nerve by using endoscopic guidance. The endoscope was introduced into the prechiasmatic cistern and provided a clear visual field around the aneurysm that could not be seen via the operating microscope. The endoscope was useful in the identification of the medially projecting lesion and the small perforating branches of the ophthalmic segment of the internal carotid artery. A fenestrated clip could be introduced around the neck of the aneurysm and placed in the best position under endoscopic guidance. Endoscopy-assisted clipping is potentially a very useful procedure for aneurysm surgery.

Aneurysm↗

PubMed2002

Anterior paraclinoid aneurysms.

OBJECT: The characteristics of a previously unclassified paraclinoid aneurysm arising from the anterolateral (dorsal) wall of the proximal internal carotid artery were retrospectively analyzed in seven patients (five women and two men) who were treated surgically for an aneurysm in this unusual location. METHODS: One patient presented with subarachnoid hemorrhage (SAH) caused by rupture of this aneurysm. The lesions were found incidentally (five cases) or during investigation of SAH due to another aneurysm (one case). There was a female predominance in this series; all female patients harbored multiple aneurysms. All patients underwent surgery. Removal of the anterior clinoid process was necessary because the proximal neck of the aneurysm was closely adjacent to the dural ring. CONCLUSIONS: This special group of aneurysms is very rare, is located exclusively in the intradural space, and carries the risk of SAH. The results of surgical treatment for this aneurysm are quite satisfactory.

Aged↗

PubMed2002

[Frontal atypical teratoid/rhabdoid tumor evaluated by single-photon emission computerized tomography and positron emission tomography].

A case of frontal atypical teratoid/rhabdoid tumor (AT/RT) was presented in the findings of single-photon emission computerized tomography (SPECT) using 201Tl-chloride (Tl) and 123I-metaiodobenzylguanidine (MIBG), and positron emission tomography using 18F-fluorodeoxyglucose (FDG) and (11C-methyl)-L-methionine (Met). A 16-year-old female had an episode of Jacksonian seizures one month prior to admission. CT scans showed an isodensity mass with heterogeneous enhancement in the left frontal lobe. MR images revealed a tumor with solid and cystic components and perifocal edema. SPECT demonstrated intense accumulation of Tl and MIBG in the enhancing lesion 15 min and 30 min after intravenous injection of tracers, respectively. The 6-hr delayed SPECT showed no retention of MIBG in the enhancing lesion. FDG-PET and Met-PET revealed high uptake of tracers in the enhancing lesion. Met did not accumulate in the frontal white matter, which appeared hyperintense on T2-weighted MR images. The patient underwent an uneventful extirpation of the solid mass, where Met had accumulated. Microscopically, the solid tumor contained rhabdoid cells, spindle-shaped cells resembling mesenchymal cells, and nests of small cells. The tumor cells were immunoreactive for vimentin, cytokeratin, and epithelial membrane antigen. The MIB-1 labeling index was 25%. The histological diagnosis was AT/RT. Postoperative course was uneventful. A dose of 32.4 Gy was administrated to the whole brain and a boost of 27.8 Gy to the T2-hyperintensity lesion. Five months after the radiotherapy, MRI showed neither abnormal enhancing lesions nor the T2-hyperintensity lesion. Multifarious studies using SPECT and PET are useful for differential diagnosis and for choosing optimal therapeutic strategy for this type of tumor.

3-Iodobenzylguanidine↗

PubMed2002

[Orbital neuroma developing in the ciliary nerve].

Orbital neuroma is a rare disease accounting for a certain percentage of all orbital tumors. However, because of the anatomical features of the orbit, the origin of the tumor has been diagnosed in only a few cases. The authors report a case of orbital neuroma arising from a short ciliary nerve that was confirmed during surgery. The patient was a 72-year-old female. She visited our hospital with complaints of left visual disturbance, exophthalmus and diplopia. Neurological examination on admission also revealed Marcus gunn pupil sign. CT scan and MRI imaging showed a left orbital tumor located along the superior surface of the optic nerve and adjacent to the posterior pole of the eye ball. She underwent superior orbitotomy through a transcranial approach. The tumor was encapsulated and adhered tightly to the sclera, short ciliary nerve, and optic nerve. For this reason, it was removed without a part of the adhered capsule. Since histological examination revealed neuroma, the tumor was diagnosed as short ciliary nerve neuroma. Postoperatively no additional deficits occurred. The exophthalmus, diplopia and Marcus gunn pupil sign disappeared and visual acuity was improved after the surgery. In such a case of short ciliary nerve neuroma, it is possible to remove the tumor without any neurological deficit, if careful consideration of microsurgical anatomy is made.

Aged↗

PubMed2002

[Third ventricular chordoid glioma: report of a surgical case].

We reported a rare case of third ventricular chordoid glioma and reviewed the literature. A 25-year-old male presented with a two-year history of voracious appetite. Three months prior to admission, he developed progressive memory impairment. CT scan showed a well circumscribed, slightly hyperdense mass without calcification in the third ventricle. The 4.5-cm oval mass occupying the anterior part of the third ventricle was homogeniously enhanced on MR images after administration of contrast medium. Small cystic components were present in the periphery of the mass. CT-guided stereotactic biopsy was performed. Microscopically, epithelioid tumor cells were embedded in mucinous stroma containing a lympho-plasmacytic infiltration. The tumor cells were immunoreactive for GFAP and vimentin. The MIB-1-positive rate was 1.2%. The histological diagnosis was a chordoid glioma. One month after the biopsy, a right frontal craniotomy was performed to remove the tumor via the anterior transcallosal interfornitial approach. The tumor arising from the anterior part of the third ventricle wall was soft, mildly vascular and light-grayish. The tumor was completely resected. The histological findings were identical with those of the biopsy specimens. Postoperatively, the patient developed diabetes inspidus, hyperthermia, worsening memory impairment, and transient hyponatremia. The patient's symptoms gradually improved and follow-up MR images showed no evidence of recurrent tumor 17 months after the resection. Despite low-grade appearance, attachment of the tumor to the hypothalamus preclude complete resection, and this may result in tumor recurrence and less favorable prognosis in the current reports. Early detection and aggressive resection followed by stereotactic radiotherapy are important in the management of chordoid glioma.

Adult↗

PubMed2002

Medulloblastoma with extensive nodularity: single photon emission CT study with iodine-123 metaiodobenzylguanidine.

We present the case of an infant with medulloblastoma with extensive nodularity, which had been called cerebellar neuroblastoma. MR imaging clearly revealed a nodular enhancement, which appeared as a grape-like lesion. Single photon emission CT revealed markedly high iodine-123 metaiodobenzylguanidine uptake in the enhancing tumor. Iodine-123 metaiodobenzylguanidine single photon emission CT may be useful in the diagnosis of medulloblastoma with extensive nodularity, which has been considered to be a subgroup of medulloblastoma with extensive neuronal differentiation.

3-Iodobenzylguanidine↗

PubMed2002

[Primary intracerebral malignant fibrous histiocytoma: case report].

We report a rare case of a primary intracerebral malignant fibrous histiocytoma (MFH) with malignant progression from a premalignant stage. A 73-year-old male presented with mild hemiparesis on the right side of his body 4 months prior to admission. MR images showed a homogenously enhanced mass in the left parietal lobe. The patient underwent an uneventful extirpation of the solid mass. Microscopically, the solid tumor contained histiocytic cells and spindle-shaped fibroblastic cells arranged in a storiform pattern. The tumor cells were immunoreactive for vimentin, MAC 387 (macrophage marker) and alpha-1-antitrypsin. The MIB-1-positive rate was 1%. The histological diagnosis was fibrous histiocytoma. Postoperative MR images demonstrated no abnormally enhanced lesions. The patient's neurological symptoms and signs gradually improved. One year after surgery, he developed right hemiparesis. MR images showed a heterogeneously enhanced mass in the left sensorimotor area. This recurrent tumor was totally resected. Microscopically, the tumor was composed of atypical spindle-shaped cells, forming a storiform pattern. Pleomorphism was prominent, and necrotic foci were also seen. The MIB-1 labeling index averaged 11%. The histological findings corresponded to those of MFH. Unfortunately, the patient died of interstitial pneumonia contracted during postoperative radiotherapy. Early detection and resection at a stage of low malignant potential, followed by radiochemotherapy, are crucial for the management of this mesenchymal tumor.

Aged↗