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Yoichi Katayama

Publications and source records attributed to Yoichi Katayama.

At least 19 recordsLinked to original sources
PubMed2007

Promoter hypermethylation profile of cell cycle regulator genes in pituitary adenomas.

Aberrant hypermethylation of CpG islands in the promoter region plays a causal role in the inactivation of various key genes involved in the cell cycle regulatory cascade, which could result in a loss of cell cycle control. The aim of the present study was to examine in more detail the prevalence and role of the promoter methylation of genes with a proven involvement in the cell cycle regulation of pituitary adenomas, since their tumorigenesis has not yet been clearly defined. We profiled the CpG island methylation status of a series of well-characterized cell cycle regulation genes: the RB1, p14(ARF), p15(INK4b), p16(INK4a), p21(Waf1/Cip1), p27(Kip1), and p73 genes, in 34 pituitary adenomas as determined by a methylation-specific polymerase chain reaction assay. Promoter hypermethylation of the RB1, p14(ARF), p15(INK4b), p16(INK4a), p21(Waf1/Cip1), p27(Kip1), and p73 genes was detected in 12 (35%), 2 (6%), 11 (32%), 20 (59%), 1 (3%), 0 (0%), and 4 (12%) of the adenomas, respectively. In total, 88% (30 of 34) of the adenomas displayed methylation of at least one of such cell cycle regulatory genes, especially methylation of the member genes of the RB1 pathway (29 of 34; 85%). Promoter hypermethylation of p15(INK4b) coincided with RB1 and/or p16(INK4a) methylation, whereas RB1 and p16(INK4a) methylations tended to be mutually exclusive (p = 0.0048). Furthermore, promoter hypermethylations of p14(ARF), p21(Waf1/Cip1), and p73 (not belonging to the member genes of the RB1 pathway) were also coincident with RB1 and/or p16(INK4a) methylation except in one p73 methylated case. In contrast, none of the clinicopathological features, including the cell proliferation index, was significantly correlated with any particular methylation status. Our results suggested that aberrant hypermethylation of the key cell cycle regulatory genes occurs at a relatively high frequency in pituitary adenomas, especially in RB1 pathway genes with promoter hypermethylation of the p16(INK4a) gene being the most common deregulation. We further obtained evidence to indicate that RB1 and p16(INK4a) methylations tended to be mutually exclusive, but did occasionally coincide with other cell cycle regulation gene methylations.

Adenoma↗
PubMed2007

Neurenteric cyst arising in the high convexity parietal lesion: case report.

OBJECTIVE: Supratentorial neurenteric cysts (NC) are rare; only 16 cases were reported previously, the majority of which were located in the anterior fossa or in the deep midline structure. We report a case of NC arising in the high convexity parietal lesion and briefly discuss the histogenesis of NC in such an unusual location. CLINICAL PRESENTATION: A 63-year-old man presented with a 1-month history of progressive headache and dizziness. Computed tomographic and magnetic resonance imaging scans demonstrated a 4 x 5 x 5 cm extra-axial cystic lesion in the right parietal convexity adjacent to the sagittal sinus without contrast enhancement. A translucent thin-walled cyst containing a milky-white fluid was partially excised via a right parietal craniotomy. INTERVENTION: The cyst wall was composed of a thin fibroconnective tissue lined by a single layer of ciliated columnar epithelial cells and pseudostratified columnar epithelium. Mucous-secreting goblet cells of epithelial lining reacted to periodic acid-Shiff staining. The internal epithelial cells were immunoreactive to cytokeratin and epithelial membrane antigen, but not to carcinoembryonic antigen, glial fibrillary acidic protein, or S-100 protein. A follow-up magnetic resonance imaging scan taken 6 months later showed resolution of mass effect without evidence of cyst recurrence. The patient was discharged home in excellent condition. CONCLUSION: A case of NC arising in the high convexity parietal lesion is described. Supratentorial NCs located far from the location of the primitive endoderm suggest the possibility that NCs could arise from ectopic endodermal tissue through an undetermined process of anomalous differentiation. Total surgical excision of the cyst wall and contents is the best treatment for the symptomatic cases. Subtotal or partial resection without injury to important neurovascular structures are reasonable alternatives, but long-term careful follow-up magnetic resonance imaging or computed tomography is necessary to monitor for recurrence of any residual lesion.

Humans↗
PubMed2007

[A case of nasal dermal sinus-cyst (NDSC) with intracranial extension].

Nasal dermal sinus-cyst (NDSC) is a rare abnormality consisting of a dermal sinus opening at the nasal skin and dermoid cyst localized in the frontobasal area. A 2-year-old boy was admitted to our hospital due to swelling of the fronto-nasal regions with pus running from an orifice situated in the nasal skin. Bone-image CT and 3D-CT revealed bone defects within the frontal skull base. MRI demonstrated that a dermoid cyst centered in a bone defect was in contact with the dura of the frontobasal area, and a dermal sinus extending to the frontonasal skin could also be detected. Surgical resection was performed by frontobasal craniotomy. The dermal sinus was followed subcutaneously into the orifice of the nasal skin. A small skin incision was made and the sinus was then totally removed. The authors describe in detail this case of NDSC which extended to the intracranium, and review the literature regarding this abnormality.

Child, Preschool↗
PubMed2006

Effects of cerebral ischemia on evoked cerebral blood oxygenation responses and BOLD contrast functional MRI in stroke patients.

BACKGROUND AND PURPOSE: To evaluate the mechanisms of failure of blood oxygenation level-dependent (BOLD) imaging in stroke, we compared the evoked cerebral blood oxygenation (CBO) responses and activation volumes (AVs) of BOLD functional MRI (fMRI) in chronic stroke patients with moderate and severe cerebral ischemia. METHODS: We measured the evoked CBO responses in the primary sensorimotor cortex (PSMC) by means of near-infrared spectroscopy during contralateral motor tasks. We compared the AV of BOLD-functional MRI in the PSMC on the nonlesion and lesion sides. Single-photon emission computed tomography was used to classify ischemic status as moderate (slight reduction of regional cerebral blood flow and cerebrovascular reserve capacity [CVRC]) or severe (marked reduction of regional cerebral blood flow and CVRC; ie, misery perfusion). RESULTS: In age-matched controls, deoxyhemoglobin concentration decreased with concomitant increases in oxyhemoglobin and total hemoglobin concentrations during activation. The PSMC on the nonlesion side exhibited a normal CBO response pattern. On the lesion side, moderate cerebral ischemia did not affect the CBO response pattern, but severe cerebral ischemia caused an increase of deoxyhemoglobin during the task, associated with increases of oxyhemoglobin and total hemoglobin. Moderate cerebral ischemia induced only a slight reduction of the AV on the lesion side; however, severe cerebral ischemia markedly reduced the AV on the lesion side. The BOLD signal did not change in some areas of the PSMC on the lesion side in severe cerebral ischemia, whereas it tended to decrease in other areas during the tasks. CONCLUSIONS: Misery perfusion caused a marked reduction of the AV on BOLD imaging, associated with an increase of deoxyhemoglobin concentration during activation. BOLD-fMRI investigations of stroke patients should be performed while giving consideration to baseline circulatory status. Functional near-infrared spectroscopy could be an alternative means to assess the CVRC.

Adult↗
PubMed2006

Intraoperative monitoring of cerebral blood oxygenation and hemodynamics during extracranial-intracranial bypass surgery by a newly developed visible light spectroscopy system.

BACKGROUND: Cerebrovascular reconstruction procedures run the risk of changing the balance between oxygen supply and consumption during surgery. We assessed the value of visual light spectroscopy for detecting changes in cerebral blood oxygenation (CBO) during superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. METHODS: We developed a VLS monitoring system which permits continuous monitoring of CBO changes during surgery. Using the VLS, we evaluated the CBO changes in the MCA territory on the lesion side in 18 patients who underwent STA-MCA anastomosis. RESULTS: Temporary occlusion of the MCA (M4 portion) did not change the CBO in 17 patients. However, in the patient with dissecting aneurysm, it caused decreases of oxyhemoglobin and cortical oxygen saturation (CoSo(2)) associated with an increase of deoxyhemoglobin, although these CBO changes were normalized by STA blood flow. In 5 patients, STA blood flow increased the oxyhemoglobin and CoSo(2) and decreased the deoxyhemoglobin, indicating that cortical blood flow (CoBF) was increased. The CoSo(2) before anastomosis was significantly low in the patients who showed an increase of CoSo(2) by STA blood flow (63.0% +/- 2.5%) as compared with those who did not (72.0 +/- 6.1%, P = .024). CONCLUSION: Temporary occlusion of a cortical artery during bypass surgery did not affect the CBO in patients who had chronic cerebral ischemia, but caused acute ischemia in the patient who did not. STA blood flow increased the CoBF during surgery more frequently in patients who showed a low perfusion pressure. The VLS monitoring system is considered useful for evaluating bypass function and facilitates safe and accurate bypass surgery.

Adolescent↗
PubMed2006

Impact of stereotactic hematoma evacuation on medical costs during the chronic period in patients with spontaneous putaminal hemorrhage: a randomized study.

OBJECTIVE: Stereotactic hematoma evacuation (SHE) has been reported to reduce mortality and to improve functional outcome in patients with spontaneous putaminal hemorrhage. Stereotactic hematoma evacuation has not been widely accepted, however, as a standard therapy because its effect on functional outcome has been regarded as marginal and insufficient to justify the costs of surgery. We reassessed the value of SHE by analyzing its impact on chronic-period medical costs based on an original randomized study carried out by us. METHODS: In total, 490 patients were entered into the study. The degree of neurologic severity was defined on admission according to the neurologic grades (NGs) ranging from NG1 to NG5, adopted by the Japanese Cooperative Study on Stroke Surgery. The NG2 and 3 patients were randomized into 2 groups with different treatment protocols (group I, SHE; group II, conservative treatment). On the other hand, the NG1, 4, and 5 patients were excluded from the randomization because a large-scale retrospective study in Japan had revealed that surgical treatment in patients assigned to these NG grades does not improve functional outcome. Among the 490 patients, 248 were excluded and 242 were randomized strictly. The latter patients comprised 148 men and 94 women. Their ages ranged from 38 to 80 years (mean, 60.5 years). The medical costs for patient care were analyzed at 1 year after onset. RESULTS: As compared with group II, group I demonstrated a lower mortality and better recovery to functional independence in NG3 patients. As compared with group II, group I revealed lower costs at 1 year after hemorrhage in NG2 patients, probably reflecting reduced neurologic deficits brought about by the SHE, and approximately the same costs in NG3 patients. CONCLUSION: Stereotactic hematoma evacuation is clearly of value from the medicoeconomical point of view in selected patients with spontaneous putuminal hemorrhage, whose eyes are closed but open to weak stimuli (NG2) or strong stimuli (NG3) on admission.

Activities of Daily Living↗
PubMed2006

TrkA expression is associated with an elevated level of apoptosis in classic medulloblastomas.

Medulloblastomas represent the most common central nervous system malignancies in children. Despite intensive modality treatment with craniospinal irradiation and multiple drug chemotherapy, their prognosis remains dismal. In the present study, we examined the potential roles of cellular differentiation, proliferation and apoptosis in 21 pediatric patients with newly diagnosed classic medulloblastomas treated by conventional radiation therapy and adjuvant chemotherapy. The expression of glial fibrillary acidic protein, S-100, synaptophysin, TrkA and TrkC, and the proliferation index of MIB-1 were evaluated by immunohistochemistry and the apoptotic index was determined using terminal deoxytransferase-mediated deoxyuridine-5'-triphosphate nick-end labeling assay. The prognostic value of these biological markers was also assessed. Immunoreactive glial fibrillary acidic protein, S-100, synaptophysin, TrkA and TrkC were observed in seven (33%), four (19%), 12 (57%), 14 (67%) and 11 (52%) of the 21 cases, respectively. TrkA expression was positively correlated with the MIB-1 staining index (P = 0.0228) and the apoptotic index (P = 0.0058). None of the immunohistochemical markers was found to be of value in predicting the prognosis. Although the present small sample size does not provide sufficient power to discount biological variables as prognostic markers, it was the well-established clinical prognostic factors, i.e. tumor stage and extent of surgery, that stood out as the most important predictors of survival. The close association between apoptosis and TrkA expression is consistent with in vitro data demonstrating the capacity of the NGF/TrkA signaling pathway to increase medulloblastoma apoptotic cell death, suggesting that this pathway may yield alternative therapeutic targets for novel therapies.

Adolescent↗
PubMed2006

Direct effect of subthalamic nucleus stimulation on levodopa-induced peak-dose dyskinesia in patients with Parkinson's disease.

We examined the direct effect of deep brain stimulation of the subthalamic nucleus (STN-DBS) on levodopa-induced peak-dose dyskinesia in 45 patients with Parkinson's disease (PD) without reducing the levodopa dosage during the early period after surgery. In 8 patients (18%), the dyskinesia was quickly attenuated by bipolar stimulation in an experimental trial (5 min) with the contacts placed within the area above the STN. In contrast, bipolar stimulation using contacts placed within the STN itself tended to provoke or exacerbate the dyskinesia, indicating that dyskinesia could be inhibited by stimulation of the areas above the STN rather than the STN itself. In an attempt to control the cardinal symptoms of PD and dyskinesia at the same time, we employed bipolar stimulation with a longer interpolar distance as a therapeutic procedure (2 weeks), using contacts within the STN as a cathode and contacts within the area above the STN as an anode. Bilateral STN-DBS significantly attenuated the dyskinesia as evaluated by the dyskinesia severity rating scale (p < 0.05). In 24 patients (53%), almost complete control of the dyskinesia was observed. The contacts used as an anode in these patients were located more dorsally compared to those of the remaining patients, suggesting again that the dyskinesia was inhibited by stimulation of the areas above the STN rather than the STN itself. In the area above the STN, pallidothalamic, pallidosubthalamic and subthalamopallidal fibers are densely distributed. It appears that stimulation of these fibers may cause effects similar to thalamic or pallidal DBS and therefore inhibit peak-dose dyskinesia. Bipolar STN-DBS with contacts placed within the area above the STN as an anode appears to represent a useful option for controlling both the cardinal symptoms of PD and peak-dose dyskinesia at the same time.

Antiparkinson Agents↗
PubMed2006

Thalamic sensory relay nucleus stimulation for the treatment of peripheral deafferentation pain.

We applied chronic deep brain stimulation (DBS) of the thalamic nucleus ventralis caudalis (Vc) for the treatment of peripheral deafferentation pain. The subjects included 11 cases of phantom limb pain and 7 of root or nerve injury pain without phantom sensation. In the phantom limb pain patients, the spike density markedly increased in the same area of the Vc where microstimulation induced paresthesia in the part with phantom sensation. Reorganization of the receptive field representation within the Vc was also demonstrated by microrecording and microstimulation. In the root or nerve injury pain patients with severe allodynia and without phantom sensation, oscillating neural hyperactivity appeared when the allodynia was induced during single-cell recording in the Vc. In both groups stimulation of these areas with the DBS electrode was useful for achieving pain reduction. Inhibition of spinothalamic tract neurons, restoration of the original receptive field representation and modulation of thalamocortical rhythmic oscillations are proposed to play important roles in a possible mechanism of Vc-DBS for the treatment of deafferentation pain.

Causalgia↗
PubMed2006

Preliminary individualized chemotherapy for malignant astrocytomas based on O6-methylguanine-deoxyribonucleic acid methyltransferase methylation analysis.

O(6)-methylguanine-deoxyribonucleic acid methyltransferase gene (MGMT) methylation is apparently correlated with responsiveness to nitrosourea chemotherapy, suggesting this alkylating agent should be effective against MGMT-methylated tumors. MGMT appears not to be linked to platinum resistance, so platinum chemotherapy should be used for MGMT-unmethylated tumors. This study was a preliminary trial of individualized chemotherapy based on MGMT methylation status in a total of 20 patients with newly diagnosed malignant astrocytomas (9 anaplastic astrocytomas and 11 glioblastomas multiforme). The procarbazine, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-2(2-chloroethyl)-3-nitrosourea, and vincristine (PAV) regimen was administered to seven patients with MGMT-methylated tumors, and the carboplatin and etoposide (CE) regimen was administered to 13 patients with MGMT-unmethylated tumors. Objective response to the PAV therapy was noted in all three patients with measurable residual tumor (2 complete responses and 1 partial response). Five of the seven patients continued to be disease-free after initiation of the PAV therapy. Objective response to the CE therapy was seen in only one of seven patients with measurable residual tumor (1 partial response). Three of the 13 patients were free from progression, whereas the remaining 10 patients showed early progression. The PAV regimen is effective against MGMT-methylated malignant astrocytomas, but the CE regimen is not useful at the given dose and schedule in MGMT-unmethylated tumors.

Adult↗
PubMed2006

[Hyperkalemia caused by intravenous administration of mannitol in a patient with arteriovenous malformation: case report].

We experienced a case in which hyperkalemia was induced by mannitol administration. The medication with mannitol was given to a 15-year-old male patient who underwent a removal operation for arteriovenous malformation under general anesthesia. Following the mannitol infusion, his arterial blood gas and electrolyte analysis revealed severe metabolic acidosis and an increase in serum potassium. Furthermore, a change in his electrocardiogram was observed. The hyperkalemia was quickly normalized by medication with calcium gluconate and sodium bicarbonate. We stopped the removal operation with the aim of giving priority to the patient's safety. It is speculated that the hyperkalemia was caused by the administration of mannitol. Checks of electrolyte levels, arterial blood gas analysis and electrocardiogram monitoring should therefore be carried out when using mannitol, especially in an emergency situation such as intracranial hemorrhage.

Acidosis↗
PubMed2006

[Spinal cord evoked potential].

Spinal cord evoked potentials (SCEPs) used as a technique for intraoperative neurophysiological monitoring can be divided into several groups depending on the stimulation method. SCEP evoked by direct motor cortex stimulation enables the recording of the descending volley passing through the corticospinal tract. Such potentials are termed D (direct)- and I (indirect)-waves. D-wave reflects the function of the corticospinal tract directly and is regarded as an appropriate parameter for the intraoperative monitoring of motor function. On the other hand, the corticospinal tract may be activated by transcranial stimulation and a potential similar to D-wave can be recorded from the spinal epidural space. Previous studies, however, indicated that the site of transcranial stimulation is around the lower level of the brainstem and the response includes the potentials coming from other neural tracts. In addition, the responses of SCEPs evoked by spinal cord and peripheral nerve stimulations are generally considered to reflect mainly the function of the deep sensory pathway. Therefore, SCEPs evoked by transcranial, spinal cord and peripheral nerve stimulations cannot be used as a parameter to monitor motor function directly. It is particularly important to know the characteristics of each SCEP and apply each potential to the most appropriate situation.

Evoked Potentials↗
PubMed2006

[A case of cerebral arteriovenous malformation revealing repeated intranidal hemorrhage accompanying neovascularization after stereotactic radiosurgery].

We report a patient with cerebral arteriovenous malformation (AVM) revealing growing mass lesion after stereotactic radiosurgery. This 12-year-old female presented headache. CT scan showed hematoma at the head of the right caudate nucleus and angiography showed AVM at the site. LINAC-based stereotactic radiosurgery was performed with the patient. Twenty-three months after the radiosurgery the patient complained headache and CT scan showed hematoma again at the same site, although angiography did not show AVM. Thirty-five months after the radiosurgery mass lesion with enhancement effect was observed at the site and the mass lesion grew gradually thereafter. Thirty-nine months after the radiosurgery the mass lesion was evacuated. Histological examination revealed fibrotic core and surrounding neovascularized area with hemorrhage. The histology shows a new etiology of growing mass lesion after radiosurgery for AVM.

Basal Ganglia↗
PubMed2006

[Superior sagittal sinus thrombosis suffered as a complication of ulcerative colitis: case report].

A case of superior sagittal sinus thrombosis which was complicated with ulcerative colitis is reported. A 16-year-old male patient had a 2-year history of ulcerative colitis. He was admitted to our hospital complaining of abdominal pain, bloody bowel discharge and appetite loss, and was then treated conservatively. Two days after admission, he demonstrated generalized convulsions which were followed by right hemiplegia. MRI showed a low intensity lesion on T1 and an irregular high intensity in the subcortical area of the left frontal lobe on T2 and T2 FLAIR-weighted images. The MRI findings resembled either invasive brain tumor or local inflammation. Cerebral angiography appeared to demonstrate complete obstruction of the superior sagittal sinus with congestion of venous flow in the cortical veins. Ulcerative colitis has been reported to show hypercoagulation, leading to deep vein thrombosis within the body which sometimes causes pulmonary infarction; however, occurrence of venous thrombosis in the intracranial veins and sinus is rare. This report underscores the fact that cerebral venous thrombosis should be suspected in the case of patients with ulceritive colitis who suffer sudden onset of neurological deficits.

Adolescent↗
PubMed2006

Aberrant promoter hypermethylation profile of cell cycle regulatory genes in malignant astrocytomas.

Aberrant hypermethylation of the CpG islands in the promoter region plays a casual role in the inactivation of various key genes involved in the cell cycle regulatory cascade, which could result in loss of cell cycle control. The aim of the present study was to investigate the role of promoter methylation of genes with a proven involvement in the cell cycle regulation of malignant astrocytomas. We profiled the CpG island methylation status of the RB1, p14ARF, p15INK4b, p16INK4a, p21Waf1/Cip1, p27Kip1, and p73 genes by methylation-specific polymerase chain reaction assay in a homogeneous cohort of patients with malignant astrocytomas, and assessed their relationships with clinical behavior. Promoter hypermethylation of the RB1, p14ARF, p15INK4b, p16INK4a, p21Waf1/Cip1, p27Kip1, and p73 genes was detected in 3 (6%), 7 (13%), 4 (7%), 2 (4%), 1 (2%), 3 (6%), and 12 samples (22%) among 54 newly diagnosed malignant astrocytomas, respectively. A total of 50% of the cases carried methylation of at least one gene, and only 9% of the cases displayed concordant hypermethylation of two genes. None of the tumors disclosed three or more methylated loci. The presence of methylation of these genes or a group of genes was not associated with any distinct clinicopathological characteristics including tumor grade, proliferation activity, responsiveness to adjuvant therapy, or patient survival. p73 protein accumulation was demonstrated by immunohistochemical staining in 6 (15%) of the 40 samples examined, with no significant association with the methylation status of p73 and any of the clinicopathological parameters tested. Our results demonstrated that a significant fraction of malignant astrocytomas displayed at least one methylated locus of the key cell cycle-related genes, although the genes were rarely hypermethylated, independent of the clinicopathological parameters. Thus, this epigenetic change is unlikely to play an important role in the evolution and development of malignant astrocytomas.

Adult↗
PubMed2005

Changes of cerebral blood oxygenation and optical pathlength during activation and deactivation in the prefrontal cortex measured by time-resolved near infrared spectroscopy.

To determine the alterations in optical characteristics and cerebral blood oxygenation (CBO) during activation and deactivation, we evaluated the changes in mean optical pathlength (MOP) and CBO induced by a verbal fluency task (VFT) and driving simulation in the right and left prefrontal cortex (PFC), employing a newly developed time-resolved near infrared spectroscopy, which allows quantitative measurements of the evoked-CBO changes by determining the MOP with a sampling time of 1 s. The results demonstrated differences in MOP in the foreheads with the subjects and wavelength; however, there was no significant difference between the right and left foreheads (p > 0.05). Also, both the VFT and driving simulation task did not affect the MOP significantly as compared to that before the tasks (p > 0.05). In the bilateral PFCs, the VFT caused increases of oxyhemoglobin and total hemoglobin associated with a decrease of deoxyhemoglobin, while the driving simulation task caused decreases of oxyhemoglobin and total hemoglobin associated with an increase of deoxyhemoglobin; there were no significant differences in evoked-CBO changes between the right and left PFC. The present results will be useful for quantitative measurement of hemodynamic changes during activation and deactivation in the adults by near infrared spectroscopy.

Adult↗