Biomedical subjects

Masafumi Fukuda

Publications and source records attributed to Masafumi Fukuda.

At least 19 recordsLinked to original sources

PubMed2006

Transcranial imaging of audiogenic epileptic foci in the cortex of DBA/2J mice.

Exposure to intense sound stimuli induces audiogenic seizures in DBA/2J mice. We investigated cortical activities during sound stimulation using flavoprotein fluorescence imaging. Most DBA/2J mice had seizures during intense sound stimulation, with more than half surviving after seizures. Surviving mice were anesthetized with urethane (1.6 g/kg, intraperitoneal), and the skull was exposed and then covered with clear resin. More than 3 days after surgery, the mice were lightly anesthetized with urethane (0.8 g/kg) and cortical activities during intense sound stimulation were visualized. Focal responses appeared near the somatosensory cortex together with spike activities localized in the response area. These findings indicate that epileptic foci of audiogenic seizure are formed in the cortex of DBA/2J mice.

Acoustic Stimulation↗

PubMed2006

[Abnormal muscle response monitoring during microvascular decompression for hemifacial spasm and long term results].

OBJECTIVE: There is some debate over the reliability of intraoperative abnormal muscle response (AMR) monitoring as an indicator of postoperative long-term outcome in patients with hemifacial spasm (HFS). We investigated whether AMR findings obtained during microvascular decompression reflect postoperative long-term outcome. MATERIAS AND METHODS: Subjects were 51 HFS patients who underwent AMR monitoring during surgery. AMR recordings were obtained from the mentalis muscle by electrical stimulation of the temporal branch of the facial nerve and from the orbicularis oculi muscles by stimulation of the marginal mandibular branch. Postoperative follow-up was more than 5 years (range 61-118 months, mean 87 months). RESULTS: In 37 patients, AMR disappeared after vascular decompression. Among those patients, only one presented with spasm at the final follow-up examination. In 6 of 7 patients with AMR that disappeared early before the completion of decompression, hemifacial spasm resolved completely. Five of six patients in whom AMR still remained but with decreased amplitude at the end of surgery experienced complete resolution. CONCLUSIONS: Our findings suggest that intraoperative cessation including prior to decompression or decreased amplitude of AMR at the end of surgery indicates a high likelihood of postoperative long-term relief of HFS. We believe that intraoperative AMR monitoring is useful in MVD surgery for HFS.

Adult↗

PubMed2005

Ictal SPECT analyzed by three-dimensional stereotactic surface projection in frontal lobe epilepsy patients.

We analyzed preoperative ictal SPECT results from 18 frontal lobe epilepsy patients who underwent epilepsy surgery (mean age 22.9 years). Seizure onset at implanted subdural electrodes was defined as the epileptic focus in 16 of 18 patients. In two additional patients, the resected area on postoperative magnetic resonance images was defined as the epileptic focus. The radioisotope 99mTc-ECD was injected in all patients within 5 s after seizure onset. SPECT images were analyzed by three-dimensional stereotactic surface projection (3-D SSP). Areas of hyperperfusion identified by ictal SPECT were concordant with the site of epileptic focus in 11 patients (61.1%, concordant group) and were non-concordant in 7 patients (38.9%, non-concordant group). The non-concordant group had a higher number of patients with a history of acquired brain damages, such as encephalitis or brain surgery (p < 0.05). Only 3 of 11 patients in the concordant group showed areas of localized hyperperfusion within epileptic foci, whereas 8 patients showed areas of hyperperfusion extending to other regions. Ictal SPECT analyzed by 3-D SSP is useful as a mode of presurgical evaluation in frontal lobe epilepsy patients without a history of encephalitis or surgical treatment. We caution that rapid seizure spread may result occasionally in areas of hyperperfusion extending to adjacent or remote regions.

Adolescent↗

PubMed2005

Neurobehavioural profile of low-birthweight infants with cystic periventricular leukomalacia.

Twenty-three low-birthweight infants (17 males, six females) diagnosed with cystic periventricular leukomalacia (PVL; median gestational age 30 wks, postmenstrual age range 25 to 36 wks; median birthweight 1365 g, range 680 to 2010 g) were evaluated and compared with 209 comparison infants (117 males, 92 females; median gestational age 33 wks, postmenstrual age range 25 to 39 wks; birthweight 1771 g, range 670 to 2460 g). There were three assessment times: 36 to 38 weeks (preterm), 40 to 42 weeks (term), and 44 to 46 weeks (post-term); the Neonatal Behavioral Assessment Scale (NBAS) was used for assessment. Outcome at 2 years was assessed on the basis of a neurological examination, magnetic resonance imaging, computerized tomography, electroencephalography, and the Mental and Psychomotor Development Indices of the Bayley Scales of Infant Development. All infants in the PVL group were found to have evidence of cerebral palsy, whereas all infants in the comparison group were normally developing. Infants with PVL performed more poorly on all elements of the NBAS examination at all three assessment times compared with the comparison group. They demonstrated poorer motor control, less responsiveness to environmental stimuli, less regulatory capacity, and more abnormal reflexes compared with the comparison group. These results suggest that LBW infants with PVL show dysfunction and/or disorganization in their neurobehavioural systems in the neonatal period. Assessment of neonatal neurobehavioural characteristics using the NBAS may assist clinicians in identifying LBW infants with PVL, and in formulating plans for the developmental care of these infants.

Age Factors↗

PubMed2004

Cortical activation in area 3b related to finger movement: an MEG study.

To evaluate cortical activation reflecting sensory feedback after finger movement, we recorded movement-related cerebral fields (MRCFs) following voluntary finger movement and somatosensory evoked fields for mixed (median) and pure cutaneous (radial) nerve stimulations (mSEFs and rSEFs) in six normal subjects. Equivalent current dipoles for movement-evoked field 1 (MEF1) in MRCFs and the component (70m) obtained in mSEFs, not clearly in rSEFs, were similarly distributed in each subject. They were located in area 3b, but both mean locations were significantly (p < 0.01) medial to N20m in mSEFs. MEF1 and 70m reflect similar cortical activities related to finger movement and have the same neuronal generator in area 3b, which is different from that of N20m.

Adult↗

PubMed2004

Bilateral medial medullary infarction due to bilateral vertebral artery dissection.

We describe a 52-year-old woman who experienced transient motor weakness and numbness of the left extremities and presented 2 days later with severe hemiparesis and sensory impairment of the right extremities and right lingual palsy. Magnetic resonance imaging (MRI) revealed bilateral upper medial medullary infarction, primarily in the left ventral portion. The findings of both three-dimensional (3D) computed tomographic and conventional angiography suggested dissection of both intracranial vertebral arteries (VAs). Medial medullary infarction is generally caused by atherosclerosis within a VA or anterior spinal artery. This is the first report of bilateral medial medullary infarction due to dissection of both intracranial VAs.

Brain Stem Infarctions↗

PubMed2004

Thalamic stimulation for parkinsonian tremor: correlation between regional cerebral blood flow and physiological tremor characteristics.

We used (15)O-labeled water (H(2)(15)O) positron emission tomography (PET) to study eight Parkinson's disease (PD) patients with unilateral ventral intermediate (Vim) thalamic nucleus deep brain stimulation (DBS) for severe tremor. Triaxial accelerometry (TRIAX) was used during imaging to obtain on-line measures of tremor characteristics. Regional cerebral blood flow (rCBF) scans together with TRIAX recordings were collected in three stimulation conditions (OFF, MID, and ON, corresponding, respectively, to 0%, 50%, and 100% reductions in mean accelerometry signal). Statistical Parametric Mapping (SPM99) revealed significant rCBF reductions during stimulation in the ipsilateral sensorimotor cortex (SMC) and the contralateral cerebellum, as well as concurrent increases in the ipsilateral ventral thalamus (P < 0.05, corrected). Covariate analysis of rCBF with physiological tremor characteristics revealed that tremor acceleration correlated positively with changes in the SMC and supplementary motor cortex ipsilaterally (P < 0.05, uncorrected), and negatively with changes in the ipsilateral cuneus (P < 0.05, corrected). After removing tremor acceleration effects, changes in tremor frequency correlated negatively with changes in the contralateral dentate nucleus and pons (P < 0.05, uncorrected). Our results suggest that Vim DBS for PD tremor modulates the activity of cerebello-thalamo-cortical pathways. Specific tremor characteristics relate to activity in different nodes of this system.

Aged↗

PubMed2004

Monitoring of the lateral spread response in the endovascular treatment of a hemifacial spasm caused by an unruptured vertebral artery aneurysm. Case report.

The lateral spread response (LSR) is used in the electrophysiological diagnosis of a hemifacial spasm or for monitoring during microvascular decompression. The authors used LSRs for intraoperative monitoring during endovascular surgery in a rare case of vertebral artery (VA) aneurysm that caused intractable hemifacial spasm. A 49-year-old woman presented with a right hemifacial spasm that had persisted for 9 months. No other clinical symptom was observed. Vertebral artery angiography revealed a saccular aneurysm of the right VA. Magnetic resonance (MR) imaging demonstrated that the aneurysm was compressing the root exit zone of the right facial nerve. Endovascular treatment of the VA aneurysm was performed while monitoring the patient's LSRs. During occlusion of the VA at sites distal and proximal to the aneurysm, the LSRs temporarily disappeared and then reappeared with a higher amplitude than those measured preceding their disappearance. The hemifacial spasm alleviated gradually and disappeared completely 6 months after treatment. The LSRs changed in parallel with the improvement in the patient's hemifacial spasms and eventually disappeared. No recurrence of symptoms has been noticed as of 18 months postoperatively. This is the first report of the use of LSR monitoring during endovascular surgery for an intracranial aneurysm that causes hemifacial spasm. Intraoperative and postoperative changes in the LSRs provided useful information regarding the pathophysiology of hemifacial spasm.

Electric Stimulation↗

PubMed2003

Assessing matrix assisted laser desorption/ ionization-time of flight-mass spectrometry as a means of rapid embryo protein identification in rice.

Rice embryo proteins were separated by two-dimensional gel electrophoresis (2-DE). A total of 105 spots were digested with trypsin and the resultant peptides were analyzed by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Raw mass spectra were fully-automatically processed and searched with selected monoisotopic masses against SWISS-PROT/TrEMBL and NCBInr databases. High quality mass spectra were obtained from 53 spots, of which 36 spots were identified including 29 not registered in databases. Fifty percent of the rice embryo proteins resolved in 2-DE could not be identified, indicating more efficient sample preparation techniques need to be developed in the future. At least four to five matching peptides were found to be essential for unambiguous identification of rice embryo proteins; peptide matching of less than four lead to ambiguous results. The suitability of peptide mass fingerprinting method as a means of rapid embryo protein identification in rice was discussed.

Databases, Protein↗

PubMed2003

Learning networks in health and Parkinson's disease: reproducibility and treatment effects.

In a previous H(2) (15)O/PET study of motor sequence learning, we used principal components analysis (PCA) of region of interest (ROI) data to identify performance-related activation patterns in normal subjects and patients with Parkinson's disease (PD). In the present study, we determined whether these patterns predicted learning performance in subsequent normal and untreated PD cohorts. Using a voxel-based PCA approach, we correlated the changes in network activity that occurred during antiparkinsonian treatment and their relationship to learning performance. We found that the previously identified ROI-based patterns correlated with learning performance in the prospective normal (P < 0.01) and untreated PD (P < 0.05) cohorts. Voxel analysis revealed that target retrieval was related to a network characterized by bilateral activation of the dorsolateral prefrontal, premotor and anterior cingulate cortex, the precuneus, and the occipital association areas as well as the right ventral prefrontal and inferior parietal regions. Target acquisition was associated with a different network involving activation of the caudate, putamen, and right dentate nucleus, as well as the left ventral prefrontal and inferior parietal areas. Antiparkinsonian therapy gave rise to changes in retrieval performance that correlated with network modulation (P < 0.01). Increases in network activation and learning performance occurred with internal pallidal deep brain stimulation (GPi DBS); decrements in these measures were present with levodopa. Our findings suggest that network analysis of activation data can provide stable descriptors of learning performance. Network quantification can provide an objective means of assessing the effects of therapy on cognitive functioning in neurodegenerative disorders.

Adult↗

PubMed2003

Unilateral oculomotor nerve paresis associated with anterior communicating artery aneurysm rupture--two case reports.

Two cases of complete unilateral oculomotor nerve palsy occurred after subarachnoid hemorrhage (SAH) due to a ruptured anterior communicating artery aneurysm. A 61-year-old female suffered left oculomotor nerve paresis after mild SAH. This paresis was probably related to pre-existing oculomotor nerve stretching caused by abnormal positioning of the posterior cerebral and superior cerebellar arteries in the premesencephalic cistern. A 70-year-old female suffered right oculomotor nerve paresis after severe SAH. Elevated intracranial pressure might have caused this paresis, but the reason for the unilateral occurrence was undetermined. Both patients were treated by clipping of the aneurysm, and the signs of oculomotor nerve paresis gradually resolved. A pattern of pupil-sparing paresis was observed during the early recovery stage in both patients.

Aged↗

PubMed2003

[Ruptured frontopolar artery aneurysm: two cases].

We report two very rare cases of subarachnoid hemorrhage due to a ruptured frontopolar artery aneurysm in the cingulate sulcus. Only two surgically treated cases have been reported. Case 1: A 69-year-old woman suffered headache and was admitted to our hospital the next day. Computed tomography (CT) revealed focal subarachnoid hemorrhage (SAH) in the interhemispheric fissure. Cerebral angiography on admission failed to show an aneurysm, but follow-up study on day 14 revealed a small aneurysm in the cingulate sulcus at the origin of the frontopolar artery arising from the callosomarginal trunk. The aneurysm was successfully clipped on day 15 and the post-operative course was uneventful. Case 2: A 43-year-old man was transferred to our hospital complaining of severe headache. CT revealed diffuse SAH in the basal and interhemispheric cistern. Cerebral angiography showed an aneurysm at the origin of the callosomarginal trunk arising from the anterior communicating artery complex and another at the callosomarginal-frontopolar bifurcation in the cingulate sulcus. Both aneurysms were successfully clipped on the day of admission, and the frontopolar artery aneurysm was shown to be the cause of the SAH.

Adult↗

PubMed2002

Efficient peptide mapping and its application to identify embryo proteins in rice proteome analysis.

Using direct N-terminal analysis, only 31 N-terminally unblocked proteins out of 100 rice embryo proteins could be identified. To obtain protein sequence information for the remaining 69 blocked proteins, we developed a simple, efficient and rapid method. Using this method, we determined the peptide maps of 20 proteins per day in 10 pmol amounts. Applying this method to rice proteome analysis, we determined the internal sequences of all 69 blocked proteins. A total of 28 proteins out of 100 analyzed showed sequence similarity to the proteins with known functions in the SWISS-PROT and NCBI databases. Alternatively, we also used peptide mass fingerprinting determined by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) to identify the rice proteins separated by two-dimensional electrophoresis (2-DE). Although peptide-mass fingerprinting is a high-throughput method, we could not easily identify all the rice proteins or genes by this method, because the complete database information on rice, is not yet available and many proteins are post-translationally modified. Therefore, at present, the improved peptide mapping method as we report here is considered to be very useful in rice proteome analysis, especially for blocked proteins.

Databases, Protein↗

PubMed2002

Pallidal stimulation for parkinsonism: improved brain activation during sequence learning.

We used (15)O-labeled water and positron emission tomography to assess the effect of deep brain stimulation of the internal globus pallidus on motor sequence learning in Parkinson's disease. Seven right-handed patients were scanned on and off stimulation while they were performing a motor sequence learning task and a kinematically matched motor execution reference task. The scans were performed after a 12-hour medication washout. Stimulation parameters were adjusted for maximal motor improvement; experimental task parameters were held constant across stimulation conditions. Internal globus pallidus stimulation improved motor ratings by 37% (p < 0.01). During the sequence learning task, stimulation improved performance as measured by several correct anticipatory movements (p < 0.01) and by verbal report (p < 0.001). Concurrent positron emission tomography imaging during learning demonstrated significant (p < 0.01) increases in brain activation with stimulation in the left dorsolateral prefrontal cortex, bilaterally in premotor cortex, and in posterior parietal and occipital association areas. Stimulation did not affect the activity of these regions during the performance of the motor execution reference task. These findings suggest that internal globus pallidus deep brain stimulation can enhance the activity of prefrontal cortico-striato-pallidothalamic loops and related transcortical pathways. Improved sequence learning with stimulation may be directly related to these functional changes.

Adult↗

PubMed2002

Dyskinesia after fetal cell transplantation for parkinsonism: a PET study.

Persistent dyskinesias in the absence of or with only minimal amounts of dopaminergic medication have been reported after dopamine cell implantation for Parkinson's disease. In this study, we used [(18)F]fluorodopa (FDOPA) and positron emission tomography to determine whether this complication resulted from specific alterations in dopamine function after transplantation. Caudate and putamen FDOPA uptake values in these patients (DYS+, n = 5) were compared with those obtained in a cohort of age- and disease duration-matched transplant recipients who did not develop this complication (DYS-, n = 12). PET signal for both groups was compared at baseline and at 12 and 24 months after transplantation. We found that putamen FDOPA uptake was significantly increased (p < 0.005) in DYS+ transplant recipients. These increases were predominantly localized to two zones within the left putamen. In addition to the posterodorsal zone in which a prominent reduction in FDOPA uptake was present at baseline, the DYS+ group also displayed a relative increase ventrally, in which preoperative dopaminergic input was relatively preserved. Postoperative FDOPA uptake did not reach supranormal values over the 24-month follow-up period. These findings suggest that unbalanced increases in dopaminergic function can complicate the outcome of neuronal transplantation for parkinsonism.

Adult↗

PubMed2002

Tc-99m ethylene cysteinate dimer SPECT in the differential diagnosis of parkinsonism.

Positron emission tomography (PET) and network analysis have been used to identify a reproducible pattern of regional metabolic covariation that is associated with idiopathic Parkinson's disease (PD). The activity of this PD-related pattern can be quantified in individual subjects and used to discriminate PD patients from atypical parkinsonians. Because PET is not commonly available, we sought to determine whether similar discrimination could be achieved using more routine single photon emission computed tomography (SPECT) perfusion methods. Twenty-three subjects with PD (age, 63 +/- 9 years), 22 subjects with multiple system atrophy (MSA; age, 64 +/- 7 years), and 20 age-matched healthy controls (age, 62 +/- 13 years) underwent SPECT imaging of regional cerebral perfusion with Tc-99m ethylene cysteinate dimer (ECD). Using network analysis, we determined whether a PD-related pattern existed in the SPECT data, and whether its expression discriminated PD from MSA patients. Additionally, we compared the accuracy of group discrimination achieved by this pattern with that of the PET-derived PD-related pattern applied to the SPECT data. Network analysis of the SPECT data identified a significant pattern characterized by relative increases in cerebellar, lentiform, and thalamic perfusion covarying with decrements in the frontal operculum and in the medial temporal cortex. Subject scores for this pattern discriminated PD patients from controls (P < 0.01) and from MSA patients (P < 0.03). Subject scores for the PET-derived PD-related pattern computed in the individual SPECT scans more accurately distinguished PD patients from controls (P < 0.005) and from MSA patients (P = 0.0002). A significant PD-related covariance pattern can be identified in SPECT perfusion data. Moreover, the disease related pattern identified previously with PET can be applied to individual SPECT perfusion scans to provide group discrimination between PD patients, healthy controls, and individuals with MSA. Because of significant individual subject overlap between groups, however, the clinical utility of this method in the differential diagnosis of Parkinsonism remains uncertain.

Aged↗

PubMed2002

Lateral spread response elicited by double stimulation in patients with hemifacial spasm.

In patients with hemifacial spasm (HFS), a lateral spread response (or abnormal muscle response) is recorded from facial muscles after facial nerve stimulation. The origin of this response is not completely understood. We studied the lateral spread responses elicited by double stimulation in 12 patients with HFS during microvascular decompression. The response was recorded from the mentalis muscle by electrical stimulation of the temporal branch of the facial nerve or from the orbicularis oculi muscles by stimulation of the marginal mandibular branch. The interstimulus intervals (ISIs) of double stimulation ranged from 0.5 to 7.0 ms. R1 was defined as the response elicited by the first stimulus, and R2 as the response elicited by the second stimulus. R1 had a constant latency and amplitude regardless of the ISI, whereas R2 appeared after a fixed refractory period without facilitation or depression in a recovery curve of latency and amplitude. From these findings, we consider that the lateral spread response is due to cross-transmission of facial nerve fibers at the site of vascular compression rather than arising from facial nerve motor neurons.

Adult↗

PubMed2002

Changes in nuclear matrix proteins during the senescence-like phenomenon induced by 5-chlorodeoxyuridine in HeLa cells.

5-Chlorodeoxyuridine (CldU) immediately induces a senescence-like phenomenon in any type of mammalian cells probably due to a change in nuclear matrix structure. We thus examined nuclear matrix proteins in HeLa cells cultured with CldU by high-resolution two-dimensional gel electrophoresis and peptide mass spectrometry. Three proteins were found to be down-regulated and one protein up-regulated by addition of CldU. In addition, one acidic protein accumulated in the nuclear matrix, although not quantitatively changed in the nuclei. Since these alterations were observed within 24h after addition of CldU, these proteins may be involved in an early step of the senescence-like phenomenon.

Antigens, Nuclear↗