Search PubMed⌕ Search

Biomedical subjects

T Kayama

Publications and source records attributed to T Kayama.

At least 19 recordsLinked to original sources
PubMed2006

Surgical resection of tumors located in subcortex of language area.

OBJECT: Although functional mapping facilitates the planning of surgery in and around eloquent areas, the resection of tumors adjacent to language areas remains challenging. In this report, we took notice that the language areas (Broca's and Wernicke's) present at the perisylvian fissure. We posit that if there is non-essential language area on the inner surface of the Sylvian fissure, safe tumor resection may be possible even if the tumor is located under the language cortex. METHODS: The study population consisted of 5 patients with intrinsic brain tumors (frontal glioma, n = 3; temporal cavernous angioma, n = 1; primary malignant central nervous system lymphoma, n = 1) located in the perisylvian subcortex, in the language-dominant hemisphere. All patients underwent awake surgery and we performed intra-operative bipolar cortical functional language mapping. When the tumor was located under the language area, the Sylvian fissure was opened and the inner surface of the opercular cortex was exposed with the patient asleep, and additional functional mapping of that cortex was performed. This enabled us to remove the tumor from the non-functioning cortex. In our series, 4 of 5 patients had not language function on the inner surface of the operculum. Only one patient, a 52-year-old man with frontal glioblastoma (Case 3) had language function on the inner surface of the frontal operculum. CONCLUSION: We suggest that even perisylvian tumors located in the subcortex of the language area may be resectable via the nonfunctioning intrasylvian cortex by a transopercular approach without resultant language dysfunction.

Adult↗
PubMed2005

Multimodal strategy for managing meningiomas in the elderly.

BACKGROUND: The incidence of brain tumors in elderly patients is increasing. It has become possible to treat meningiomas in the elderly by several modalities. We developed a successful multimodal strategy to treat these patients. METHODS: We registered 35 patients with meningiomas. Symptomatic meningiomas were treated surgically at the time of diagnosis (n=19). Of the 16 asymptomatic meningiomas, 5 were removed at the time of diagnosis. The other asymptomatic meningiomas (n=11) were treated conservatively and when the tumors increased in size, surgical treatment was considered. "Operated" patients with residual or recurrent tumors underwent radiosurgery with a gamma knife. FINDINGS: Surgical mortality and morbidity were 4% and 16%, respectively. Of the 25 "operated" patients, 21 (84.0%) had a good Karnofsky scale (> or =80%) at discharge. In all but two of the 11 patients with asymptomatic, conservatively treated meningiomas, the tumors did not increase during the follow-up period. Gamma knife radiosurgery, performed to treat 3 residual and 1 recurrent tumor, resulted in very good tumor control and none of the tumors increased after gamma knife surgery. CONCLUSIONS: Meningiomas in elderly patients require a multimodal approach. Our strategy, which includes surgery, radiosurgery, and conservative treatment, resulted in good tumor control and made it possible for patients to pursue their activities of daily life.

Age Factors↗
PubMed2004

Lateral and medial medullary infarction: a comparative analysis of 214 patients.

BACKGROUND AND PURPOSE: No large-scale study has ever compared the clinical and radiological features of lateral medullary infarction (LMI) and medial medullary infarction (MMI). The aim of this study was to investigate them through the use of cooperatively collected cases. METHODS: Medical information on all patients from 1996 to 2000 with medullary infarction (MI) proven by brain MR images at 35 stroke centers in the Tohoku district, Japan, was collected, and their clinical and radiological features were analyzed. RESULTS: A total of 214 cases of MI were registered. They included 167 cases (78%) of LMI, 41 (19%) of MMI, and 6 (3%) of LMI plus MMI. The mean age of onset and the male-to-female ratio were 60.7 years and 2.7:1 in LMI and 65.0 years and 3.6:1 in MMI, respectively. The middle medulla was most frequently affected in LMI, and the upper medulla was most frequently affected in MMI. Dissection of the vertebral artery was observed in 29% of LMI and 21% of MMI. Prognosis, assessed by the Barthel Index, was favorable in both LMI and MMI. Diabetes mellitus was more frequently associated with MMI than with LMI. CONCLUSIONS: The present study surveyed a large number of MI cases and revealed that (1) the mean age of onset of MMI is higher than that of LMI, (2) the dissection of the vertebral artery is an important cause not only of LMI but also of MMI, and (3) diabetes mellitus is frequently associated with MMI.

Age Factors↗
PubMed2002

Endoscopic approach to the pituitary lesions: contemporary method and review of the literature.

The present status of endoscopic transsphenoidal surgery is introduced and reviewed. The difference between endoscopic and microscopic transsphenoidal surgery is explained and also the characteristics of the transnostril approach is mentioned. The advantages of endoscopic surgery are (1) good anatomical orientation with wider view, (2) tumors at the dead angle can be removed under the direct visualization, and (3) the patients can drink, eat and even brush their teeth just after surgery. Short hospital stay and even day-surgery could be possible when a patient is carefully selected. The disadvantages and the limitation of endoscopic surgery have been solved and improved with several new instruments and ideas. Moreover, we have made use of the surgical simulation with the three-dimensional (3-D) CT virtual navigation endoscopic image and the navigation system with the ENT application and the SureTrak of the Stealth Station. There is no need for head fixation with a Mayfield clamp or a C-arm intraoperative fluoroscopic image. This image guidance enabled a correct and smooth approach even in those patients with complicated and abnormal anatomical structures by prior surgery such as for sinusitis. The sellar floor can be safely and correctly opened even in patients with conchal type sphenoid sinus using a navigation system that helps to understand the locations of the cavernous sinus and the internal carotid arteries. The overall result by endoscopic transsphenoidal surgery is as good as or better than that by the traditional microscopic transsphenoidal surgery.

Endoscopy↗
PubMed2001

Spin trapping agent, phenyl N-tert-butylnitrone, reduces nitric oxide production in the rat brain during experimental meningitis.

Phenyl N-tert-butylnitrone (PBN) is a spin trapping agent previously shown to exert a neuroprotective effect in infant rat brain during bacterial meningitis. In the present study, we investigated the effect of systemic PBN administration on nitric oxide (NO) production in a rat model of experimental meningitis induced by lipopolysaccharide (LPS). We assessed the NO concentration in rat brain tissues with an electron paramagnetic resonance (EPR) NO trapping technique. In this model, rats receiving intracisternal LPS administration showed symptoms of meningitis and cerebrospinal fluid (CSF) pleocytosis. The time course study indicated that the concentration of NO in the brain reached the maximum level 8.5 h after injection of LPS, and returned to the control level 24 h after the injection. When various doses of PBN (125-400 mg/kg) were injected intraperitoneally 30 min prior to LPS, NO production in the brain was reduced with increasing PBN dose (250 mg/kg suppressed 80% at 8.5 h after LPS injection), and white blood cells (WBC) in CSF were significantly decreased. We concluded that reduction of NO generation during bacterial meningitis contributes to the neuroprotective effect of PBN in addition to its possible direct scavenging of reactive oxygen intermediate (ROI).

Animals↗
PubMed2001

RIZ, the retinoblastoma protein interacting zinc finger gene, is mutated in genetically unstable cancers of the pancreas, stomach, and colorectum.

The retinoblastoma protein interacting zinc finger (RIZ) gene is a candidate tumor suppressor gene on 1p36, a region frequently rearranged in a wide variety of human tumors. As the RIZ gene harbors several microsatellites within its coding region, it is a candidate for an inactivating mutation in microsatellite instability (MSI) mediated carcinogenesis. In this study, we examined mutations of two poly adenine tracts, A(8) and A(9), within the coding region of the RIZ gene, in MSI-high (MSI-H) primary cancers occurring in the pancreas, stomach, and colorectum. Frameshift mutations were found in one (10%) of 10 pancreatic, four (36%) of 11 gastric, and two (25%) of eight colorectal cancers. These results indicate that mutations of the RIZ gene play an important role in the pathogenesis of some MSI-H cancers.

Colorectal Neoplasms↗
PubMed2000

Histidine 20, the crucial proximal axial heme ligand of bacterial heme oxygenase Hmu O from Corynebacterium diphtheriae.

The hemin complex of Hmu O, a 24-kDa soluble heme degradation enzyme in Corynebacterium diphtheriae, is coordinated axially to a neutral imidazole of a proximal histidine residue in Hmu O. To identify which of the eight histidines in Hmu O is the proximal heme ligand, we have constructed and expressed the plasmids for eight His --> Ala Hmu O mutants. Reconstituted with hemin, the active site structures and enzymatic activity of these mutants have been examined by EPR, resonance Raman, and optical absorption spectroscopy. EPR of the NO-bound ferrous heme-Hmu O mutant complexes reveals His(20) as the proximal heme ligand in Hmu O, and this is confirmed by resonance Raman results from the ligand-free ferrous heme-H20A. All eight His --> Ala mutants bind hemin stoichiometrically, proving that none of the histidines is essential for hemin-Hmu O formation. However, His(20) is crucial to Hmu O catalysis. Its absence by point mutation has inhibited the conversion of hemin to biliverdin. The ferric heme-H20A complex is pentacoordinate. Resonance Raman of the CO-bound ferrous heme-H20A corroborates this and reveals an Fe-C-O bending mode, delta(Fe-C-O), the first reported for a pentacoordinate CO-bound hemeprotein. The appearance of delta(Fe-C-O) in C. diphtheriae Hmu O H20A but not mammalian HO-1 mutant H25A indicates that the heme environment between the two heme oxygenases is different.

Alanine↗
PubMed2000

Detection of amplification of a chromosomal fragment at 6p21 including the cyclin D3 gene in a glioblastoma cell line by arbitrarily primed polymerase chain reaction.

DNA from 10 human glioma cell lines was analyzed by arbitrarily primed polymerase chain reaction. By fingerprinting of the DNA fragments obtained, the presence of fragment Qx with an abnormal signal was detected in one of the glioblastoma cell lines, CCF-STTG1. The nucleotide sequence of this fragment of 387 base pairs showed no homology with any known sequences. Southern-blot analysis using Qx as a probe revealed that the abnormal signal was caused by amplification of DNA by about 50-fold. By analysis of radiation hybrid panels, the fragment was shown to be derived from a chromosomal region on 6p21. The cyclin D3 (ccnd3) gene and an EST locus, H40682, both of which were located in this region, were amplified by about 50-fold in this cell line. Two other loci, R75654 and M78872, flanking the Qx, CCND3 and H40682 loci, were not amplified, suggesting that the size of the amplicon was less than 62 cR. Since over-expression of the ccnd3 gene, but not the H40682 locus, was detected in the cell line CCF-STTG1, the increased amounts of cyclin D3 caused by gene amplification could be involved in the development and/or progression of this glioblastoma.

Blotting, Northern↗
PubMed2000

Phase II trial of pre-irradiation KRN8602 (MX2) in malignant glioma patients.

KRN8602 (MX2) is a newly developed morpholino anthracycline that crosses the blood-brain barrier where it becomes distributed in brain tissue after intravenous administration. This morpholino anthracycline has been found to be effective against human glioma cells and the intracerebrally transplanted tumors in vivo, We performed a phase II trial using KRN8602 as a single agent in malignant glioma patients who had not received prior adjuvant therapy. The 13 patients (5 glioblastomas, 7 anaplastic astrocytomas and 1 malignant oligodendroglioma) enrolled received at least 1 cycle of KRN8602 at 35 mg/m2/day in 3-4 week intervals by intravenous bolus. Ten of these patients could be evaluated for response, and 13 for toxicity. Three patients (1 glioblastoma and 2 anaplastic astrocytomas) demonstrated a complete response (3/10, 30%). Concerning side effects, myelosuppression was moderately severe, with 30.7% of patients developing grade 3 leukopenia. Severe nausea/vomiting was observed in 69% of the patients, however, cardiotoxicity was not observed. The results indicate that KRN8602 demonstrated modest activity against malignant glioma with relatively severe, but manageable toxicity. Further assessment of the efficacy and toxicity of KRN8602 against malignant glioma may be worthwhile.

Adult↗
PubMed2000

[A successfully operated case of choriocarcinoma with recurrent intratumoral hemorrhage].

A 12-year-old boy with primary intracranial choriocarcinoma of the pineal region suffered from repeated intratumoral hemorrhage over a short period. Neuroradiological images demonstrated a pineal-region tumor with intratumoral hemorrhage and obstructive hydrocephalus. HCG-beta subunit concentration of his serum and cerebrospinal fluid was abnormally high. After the 24.2Gy irradiation, the tumor was removed almost totally. After the operation, we treated him with additional radiation and chemotherapy using ifosfamide, cisplatin, and etoposide (namely ICE therapy). No recurrence or metastasis has been noted, and he was in good condition during the 22 months since the operation. At present he receives maintenance ICE therapy every 3 months. Choriocarcinoma involves a high possibility of intratumoral fatal hemorrhage, so a radical operation is recommended as soon as possible.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

[Suprasellar primary malignant rhabdoid tumor in an adult: a case report].

Malignant rhabdoid tumor (MRT), described for the first time in 1978 in the kidney, has rarely been reported in other organs including the brain and has involved adults in only 3 cases. We described a case of MRT in a 32-year-old woman who presented with severe headache, nausea and sudden onset of visual disturbance. MRI showed a well-enhanced mass at the suprasellar region. Subtotal removal of the tumor was performed. However, tumor regrowth occurred after the operation (doubling time, 8.36 days) and spinal dissemination was detected. Therefore, chemotherapy and radiotherapy were administered focusing on the suprasellar lesion and the spinal cord. Pathologically, light micrographs showed rhabdoid cells with large, round, single or double nuclei with one prominent nucleolus and eosinophilic cytoplasmic inclusions. Electron micrographs were made of typical rhabdoid cells displaying bundles of intermediate filaments within the perikaryon. In immunohistochemical studies, EMA, vimentin, cytokeratin and SMA were positive. Pathological findings were consistent with those of MRT. Optimal treatment for this tumor has not been established. Our case may be useful in defining treatment for MRT.

Adult↗
PubMed2000

[Radiation induced glioblastoma: a case report].

We report a surgical case of a 54-year-old woman with a radiation induced glioblastoma. At the age of 34, the patient was diagnosed to have a non-functioning pituitary adenoma. It was partially removed followed by 50 Gy focal irradiation with a 5 x 5 cm lateral opposed field. Twenty years later, she suffered from rapidly increasing symptoms such as aphasia and right hemiparesis. MRI showed a large mass lesion in the left temporal lobe as well as small mass lesions in the brain stem and the right medial temporal lobe. These lesions situated within the irradiated field. Magnetic resonance spectroscopy revealed relatively high lactate signal and decreased N-acetyl aspartate, choline, creatine and phosphocreatine signals. Increased lactate signal meant anaerobic metabolism that suggested the existence of a rapidly growing malignant tumor. Thus, we planned surgical removal of the left temporal lesion with the diagnosis of a radiation induced malignant glioma. The histological examination revealed a glioblastoma with radiation necrosis. MIB-1 staining index was 65%. Postoperatively, her symptoms improved, but she died from pneumonia 1 month after the surgery. An autopsy was obtained. The lesion of the left temporal lobe was found to have continuity to the lesion in the midbrain, the pons and the right temporal lobe as well. High MIB-1 staining index suggested that a radiation induced glioblastoma had high proliferative potential comparing with a de novo and a secondary glioblastoma.

Adenoma↗
PubMed2000

[Hemifacial spasm due to a compression of the facial nerve by a fusiform aneurysm of the vertebral artery: case report].

We report a rare case of symptomatic hemifacial spasm caused by a fusiform vertebral artery aneurysm and by a branch of the anterior inferior cerebellar artery compressing the facial nerve at the root exit zone (REZ). A 71-year-old female had an 11-year history of right hemifacial spasm. MRIs demonstrated an aneurysm compressing the facial nerve at the REZ. Angiography disclosed a fusiform aneurysm of the right vertebral artery at the origin of the posterior inferior cerebellar artery. After the vertebral aneurysm was clipped distal to the origin of the posterior inferior cerebellar artery, a branch of the right anterior inferior cerebellar artery was also observed compressing the facial nerve at the REZ. Both the clipped aneurysm and the branch of the anterior inferior cerebellar artery were mobilized away from the REZ of the facial nerve, and a prosthesis was inserted between the branch of the anterior inferior cerebellar artery and the brain stem to keep the aneurysm away from its original position. The patient's hemifacial spasm immediately disappeared without any neurological deficits just after the surgery. Hemifacial spasm, especially caused by an aneurysm, is quite rare. In a review of the literature, we found only 4 cases of symptomatic hemifacial spasm caused by an aneurysm of the vertebral artery. This case is the first reported case of hemifacial spasm caused by both a fusiform vertebral artery aneurysm and a branch of the anterior inferior cerebellar artery compressing the facial nerve at the REZ.

Aged↗
PubMed2000

[Ependymoma].

Explore the source record for details and available documents.

Brain Neoplasms↗