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Biomedical subjects

E Asano

Publications and source records attributed to E Asano.

At least 19 recordsLinked to original sources
PubMed2005

Chaos analysis of electro encephalography and control of seizure attack of epilepsy patients.

In order to evaluate the EEG of patients with epilepsy, chaos analysis was performed for the subdural EEG time series data. The chaos attractor was reconstructed in the phase space and the correlation dimension. KS entropy calculated from the Lyapunov exponents was evaluated. Before the seizure attack, the KS entropy showed a lower value when compared with the time series data recorded during healthy condition. The results of our study suggest that it is possible to predict the seizure attack by the chaos analysis of the EEG signal. Further, we aim at developing an automatic control system for predicting a seizure attack by the use of local cooling of the focus with Peltier elements.

Algorithms↗
PubMed2004

Lattice imaging in low-angle and high-angle bright-field scanning transmission electron microscopy.

Atomic resolution low-angle bright-field (LABF) scanning transmission electron-microscope (STEM) images and high-angle bright-field (HABF) STEM images of [011]-orientated Si have been experimentally obtained together with high-angle annular dark-field (HAADF) STEM images. The contrast formation mechanisms of the LABF STEM and HABF STEM images are examined in comparison with HAADF STEM images. The HABF STEM images independent of defocus and thickness have spatial resolution comparable with HAADF STEM images, and are shown to be given as a simple convolution under the non-dispersion approximation of localized Bloch waves.

Journal Article↗
PubMed2004

Symmetries in BF and HAADF STEM image calculations.

Reductions in bright-field (BF) scanning transmission electron microscopy (STEM) and high-angle annular dark-field (HAADF) STEM image calculations with the aid of Bloch wave symmetry are discussed under assumptions that an absorption potential is written by a local potential and a zero-order Laue zone lies parallel to the crystal surface. Translational symmetry allows us to take only partial incident beams in the first Brillouin zone instead of enormous number of partial incident beams in a large convergent disk. Two dimensional point group confines partial incident beams to an irreducible area in addition to factoring a dispersion matrix into noninteracting submatrices on a high symmetry line using the projection operator. The drastic reductions in computing time and memory enable us to readily calculate various BF STEM and HAADF STEM images. The validity and accuracy are demonstrated in comparisons with high resolution experimental BF STEM and HAADF STEM images.

Algorithms↗
PubMed2003

Rasmussen encephalitis associated with Parry-Romberg syndrome.

Parry-Romberg syndrome is a rare disorder associated with unilateral facial atrophy involving skin, subcutaneous tissue, skeletal muscle, and bone. Occasionally, there is CNS involvement with epilepsy being the most common CNS manifestation. The authors report a child with Parry-Romberg syndrome with a course strongly suggestive of Rasmussen encephalitis. The boy underwent hemispherectomy, and pathology showed the typical findings of Rasmussen encephalitis, suggesting that these two conditions may share common etiologic factors.

Child↗
PubMed2003

Alpha-methyl-L-tryptophan PET detects epileptogenic cortex in children with intractable epilepsy.

BACKGROUND: In children with tuberous sclerosis, the PET tracer alpha[11C]methyl-L-tryptophan (AMT) has been shown to be selectively taken up by epileptogenic tubers, thus allowing differentiation from nonepileptogenic tubers in the interictal state. OBJECTIVE: To determine whether cortical areas showing increased AMT uptake in children without tuberous sclerosis complex with intractable neocortical epilepsy indicate the epileptogenic zone, and to assess the relative contributions of AMT and 2-deoxy-2[18F]fluoro-D-glucose (FDG) PET abnormalities to the localization of epileptogenic cortical regions. METHODS: Areas of increased AMT and decreased FDG uptake were marked objectively as regions with abnormal asymmetry using an in-house written software in 27 children who underwent comprehensive evaluation for resective epilepsy surgery. The marked PET abnormalities were compared to the locations of scalp and subdural EEG epileptiform abnormalities, as well as histology and surgical outcome. RESULTS: Focal cortical increases of AMT uptake were found in 15 patients. The lobar sensitivity (39.0%) of AMT PET for seizure onset was lower, but its specificity (100%) was higher (p < 0.0001) than that of hypometabolism on FDG PET (sensitivity 73.2%, specificity 62.7%). AMT PET abnormalities were smaller than corresponding FDG PET hypometabolic regions (p = 0.002), and increased AMT uptake occurred in two patients with nonlocalizing FDG PET. Histologically verified cortical developmental malformations were associated with increased AMT uptake (p = 0.044). Subdural electrodes adjacent to the area of increased AMT uptake were most often involved in seizure onset. CONCLUSIONS: Focal increase of cortical AMT uptake in children is less sensitive but more specific for the lobe of seizure onset than corresponding FDG PET hypometabolism, and it is often associated with epileptogenic cortical developmental malformations. AMT PET can assist placement of subdural electrodes even when MRI and FDG PET fail to provide adequate localizing information. Cortical areas adjacent to increased AMT uptake should be carefully addressed by intracranial EEG because these regions often show a high degree of epileptogenicity.

Adolescent↗
PubMed2001

Autism in tuberous sclerosis complex is related to both cortical and subcortical dysfunction.

OBJECTIVE: To examine the relationship between autism and epilepsy in relation to structural and functional brain abnormalities in children with tuberous sclerosis complex (TSC). METHODS: Children with TSC and intractable epilepsy underwent MRI as well as PET scans with 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) and alpha-[(11)C]methyl-L-tryptophan (AMT). Based on the results of Autism Diagnostic Interview-Revised, Gilliam Autism Rating Scale, and overall adaptive behavioral composite (OABC) from Vineland Adaptive Behavior Scale, subjects were divided into three groups: autistic (OABC < 70; n = 9), mentally-retarded nonautistic (OABC < 70; n = 9), and relatively normal intelligence (OABC > or = 70; n = 8). RESULTS: PET studies showed that the autistic group had decreased glucose metabolism in the lateral temporal gyri bilaterally, increased glucose metabolism in the deep cerebellar nuclei bilaterally, and increased AMT uptake in the caudate nuclei bilaterally, compared to the mentally-retarded nonautistic group. In addition, a history of infantile spasms and glucose hypometabolism in the lateral temporal gyri were both significantly associated with communication disturbance. Glucose hypermetabolism in the deep cerebellar nuclei and increased AMT uptake in the caudate nuclei were both related to stereotypical behaviors and impaired social interaction, as well as communication disturbance. CONCLUSIONS: These results suggest that generalized epilepsy in early life and functional deficits in the temporal neocortices may be associated with communication delays, and that functional imbalance in subcortical circuits may be associated with stereotypical behaviors and impaired social interaction in children with TSC.

Adolescent↗
PubMed2001

Sturge-Weber syndrome: correlation between clinical course and FDG PET findings.

OBJECTIVE: To determine whether the extent and degree of glucose hypometabolism defined by PET correlate with seizure characteristics, cognitive function, and interictal EEG abnormalities in children with unilateral cerebral involvement of Sturge-Weber syndrome (SWS). METHODS: 2-Deoxy-2[18F]fluoro-D-glucose (FDG) PET was performed in 13 children (age range 0.7 to 15.1 years; five boys, eight girls) with unilateral SWS. Based on asymmetries between homologous cortical areas in FDG PET images, cortical areas of mildly (10% to 20% decrease), and severely (>20% decrease) asymmetric cortical metabolism were defined. These areas were normalized to the size of the ipsilateral hemisphere and correlated with clinical seizure characteristics, full-scale IQ, and interictal EEG abnormalities. RESULTS: Both seizure frequency (p = 0.027) and lifetime number of seizures (p = 0.017) showed a positive correlation with the area (expressed as the percentage of cortical area of ipsilateral hemisphere) of mildly asymmetric cortical metabolism. Patients with higher IQ had a shorter duration of epilepsy (p = 0.044) and a larger area of severely asymmetric cortical metabolism (p = 0.044). Patients with bilateral interictal EEG abnormalities had larger lifetime number of seizures (p = 0.042), lower IQ (p = 0.024), and smaller area of severely asymmetric cortical metabolism (p = 0.019) than those with only ipsilateral EEG abnormalities. CONCLUSIONS: Association of severely asymmetric cortical metabolism with relatively preserved cognitive function in SWS suggests that functional reorganization occurs more readily when cortex is severely rather than mildly damaged. Therefore, the area of mildly asymmetric cortical metabolism may exert a nociferous effect on the remaining of the brain. Thus, the extent and degree of glucose asymmetry detected by PET are sensitive markers of seizure severity and cognitive decline in SWS.

Adolescent↗
PubMed2001

Surgical treatment of West syndrome.

The discovery of focal or multifocal cortical lesions using magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning in the majority of infants with West syndrome has led to a surgical approach in the treatment of some patients with intractable infantile spasms. The locations of these lesions should be concordant with localization of focal ictal and/or interictal electroencephalographic (EEG) abnormalities prior to proceeding with cortical resection. When a single lesion is present on the MRI or PET, and there is good correlation with EEG localization, surgical treatment is generally quite favorable in terms of both seizure control and cognitive development. Interictal glucose metabolism PET scans in children with intractable cryptogenic infantile spasms show unifocal cortical hypometabolism in about 20% of cases. In the majority, however, multifocal asymmetric hypometabolism is suggestive of multifocal underlying lesions, possibly multifocal cortical dysplasia. When the pattern of glucose hypometabolism is symmetric, a lesional etiology is less likely, thus neurometabolic or neurogenetic disorders should be considered. Therefore, the pattern of glucose hypometabolism on PET in infants with intractable cryptogenic spasms is a useful guide to decide whether a medical or surgical approach should be undertaken. In order to achieve the best cognitive outcome with surgery, it is important to resect the entire 'nociferous' area rather than just the seizure focus. Our research with new PET imaging probes has attempted to provide a comprehensive evaluation of the epileptogenic zone including the 'nociferous' cortex. We have used [(11)C]flumazenil (FMZ), which labels gamma aminobutyric acid(A) (GABA(A)) receptors, and have found this to be particularly useful in showing: (i) decreased receptor binding with medial temporal involvement thus indicating resection of medial temporal structures, (ii) the peri-lesional epileptogenic zone surrounding MRI lesions, (iii) the seizure onset zone in MRI-negative cases, and (iv) potential secondary epileptic foci. Another recently developed PET probe, alpha[(11)C]methyl-L-tryptophan (AMT) which is a precursor for the serotonin and the kynurenine metabolism pathways, is capable of differentiating between epileptogenic and non-epileptogenic tubers in patients with tuberous sclerosis complex and intractable epilepsy (including infantile spasms). Subsequently, we have applied AMT PET in patients with multifocal cortical dysplasia to determine the predominant seizure focus, and the results have been promising with regard to seizure control but not cognitive development. Thus, the introduction of newer more specific PET probes for epilepsy has led to improved and more accurate localization of seizure foci that should ultimately improve outcome of epilepsy surgery in West syndrome.

Electroencephalography↗
PubMed2001

A study of novel polymorphisms in the upstream region of vasoactive intestinal peptide receptor type 2 gene in autism.

We investigated the vasoactive intestinal peptide receptor type 2 (VIPR2) gene as a candidate gene for autism. We searched for mutations in the VIPR2 gene in autistic individuals, and 10 novel polymorphisms were identified. Three polymorphisms in the upstream region were studied in detail, and there was no significant difference in the frequencies between the autistic group (n = 14) and unrelated controls (n = 52). The distribution of the genotypes in two of the three polymorphisms differed somewhat between autistic subjects with gastrointestinal problems and those without. Moreover, there was a trend showing a correlation between the genotypes for the third polymorphism and the severity of stereotypical behavior as ranked by the Gilliam Autism Rating Scale. These preliminary results suggest that VIPR2 may have a role in gastrointestinal symptoms and stereotypical behaviors in autism, although a larger collection of samples suitable for transmission disequilibrium tests is necessary to validate the results.

Autistic Disorder↗
PubMed2000

Multimodality imaging for improved detection of epileptogenic foci in tuberous sclerosis complex.

OBJECTIVE: Using interictal alpha-[11C]methyl-l-tryptophan ([11C]AMT) PET scan, the authors have undertaken a quantitative analysis of all tubers visible on MRI or 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) PET, to determine the relationship between [11C]AMT uptake and epileptic activity on EEG. BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder, often associated with cortical tubers and intractable epilepsy. The authors have shown previously that [11C]AMT PET scans show high tracer uptake in some epileptogenic tubers and low uptake in the remaining tubers. METHODS: Eighteen children, age 7 months to 16 years, were studied. Patients underwent video-EEG monitoring, PET scans of [11C]AMT and [18F]FDG, and T2-weighted or fluid-attenuated inversion recovery (FLAIR) MRI. [11C]AMT uptake values were measured in 258 cortical tubers delineated with coregistered MRI or [18F]FDG scans. Uptake ratios were calculated between the [11C]AMT uptake in tubers and those for normal cortex (tuber/normal cortex). Using the region of epileptiform activity, the authors performed receiver operator characteristics (ROC) analysis and determined the optimal uptake ratio for detecting presumed epileptogenic tubers. RESULTS: Tuber uptake ratios ranged from 0.6 to 2.0. Tuber uptake ratios in the epileptic lobes were higher than those in the nonepileptic lobes (p < 0.0001). All 15 patients with focal seizure activity showed one or more lesions with uptake ratio above 0.98 in the epileptic lobe. ROC analysis showed that a tuber uptake ratio of 0.98 resulted in a specificity of 0.91. CONCLUSIONS: Cortical tubers with [11C]AMT uptake greater than or equal to normal cortex are significantly related to epileptiform activity in that lobe. Together, interictal [11C]AMT PET and FLAIR MRI improve the detection of potentially epileptogenic tubers in patients with TSC being evaluated for epilepsy surgery.

Adolescent↗
PubMed1999

Surgical treatment of intractable epilepsy originating from the primary sensory area of the hand--case report.

A 14-year-old right-handed girl presented with intractable epilepsy originating from the primary sensory area of the hand, manifesting as sensory partial seizures in the left hand with secondary generalization. Neurological examination showed no abnormal findings. Magnetic resonance imaging, magnetoencephalography, and cortical stimulation using chronic subdural electrodes demonstrated a lesion located in the primary sensory cortex of the hand, in which the ictal onset zone was identified by 24-hour intracranial electroencephalographic recording. Surgical resection of the lesion and multiple subpial transections of the adjacent cortices were performed. The histological diagnosis was dysembryoplastic neuroepithelial tumor (DNT). She was completely free of seizures without permanent sensory deficits postoperatively. DNT located in the primary sensory hand area may be resectable without causing postoperative sensory deficits, if accurate functional mapping and surgical resection are performed.

Adolescent↗
PubMed1999

[Pathological features of dysembryoplastic neuroepithelial tumor (DNT): study of five surgical cases with intractable epilepsies].

The dysembryoplastic neuroepithelial tumor (DNT), characterized by its favorable prognosis, must be precisely differentiated from other gliomas to prevent overtreatment by radio/chemotherapy. We studied, here, pathological features of five surgical cases of DNT with intractable epilepsies. There were two males and three females with a median age of 20.4 years (range 12-41). We evaluated lesional topography, gross appearances and microscopic findings including immunohistochemical data. One tumor was located in the temporal lobe, another two in the parietal lobe, another in the occipital lobe, and the other one in the occipito-parietal junction. The lesions were predominantly intracortical in all cases. Macroscopically, two tumors were grayish-soft, another two were yellowish-elastic, and the other one was resected as soft-mucinous fragments. Microscopically, the main glial components were oligodendrocyte-like cells (OLCs) in all cases, except for one case in which atypical glial cells were also prominent. Histopathological characteristics of the DNTs included the specific glioneuronal elements (the mixture of OLCs and neurons) in four cases, alveolar pattern (all cases), microcystic degeneration (all cases), multinodular architecture (four cases), and adjacent cortical dysplasia (all cases). Immunohistochemically, Ki-67 labelling indices ranged from 0 to 0.8%. OLCs were positive for glial fibrillary acidic protein in two cases, for S-100 protein in all cases, for synaptophysin in two cases, and for class III beta tubulin in all cases. Pathological features of our cases were characterized by its heterogeneous histological appearances and divergent cellular differentiation.

Adolescent↗
PubMed1997

Hepatic arterial infusion chemotherapy combined with hyperthermia for metastatic liver tumors of colorectal cancer.

The efficacy of combined hepatic arterial infusion chemotherapy and hyperthermia for unresectable hepatic tumors of colorectal cancer was retrospectively compared with hepatic arterial infusion chemotherapy alone. Nine cases were treated with combination therapy and eight cases were treated with hepatic arterial infusion alone. The response rate in the combined hepatic arterial infusion/hyperthermia group was higher (44% v 25%) and the survival period longer (2-year survival, 35% v 12%) than in the group treated with hepatic arterial infusion alone. The toxicity was not severe, with the exception of gastrointestinal symptoms, suggesting that this combination of modalities is useful in the treatment of metastatic liver tumors.

Aged↗
PubMed1985

[Effective postoperative chemotherapy of gastric cancer associated with disseminated carcinomatosis of the bone marrow].

A 35-year-old woman tuffering from gastric cancer associated with disseminated carcinomatosis of the bone marrow is reported. Total gastrectomy combined with splenectomy and distal pancreatectomy was performed. The patient was treated with mitomycin C, FT-207, OK-432, and PSK. But serum ALP (alkaline phosphatase) and CEA (carcinoembryonic antigen) values showed gradual elevations followed by deterioration of the patient's general condition. Consequently, chemotherapy program consisting of 5-fluorouracil, Adriamycin (intra-arterially), and cisplatin (intravenously) was initiated. Serum CEA and ALP values were considerably improved, and patient was restored to a better condition. She survived 17 months and died of disseminated intravascular coagulation.

Adenocarcinoma↗
PubMed1983

[Clinical experience with T-1982 (cefbuperazone) in the pediatric field].

T-1982 (cefbuperazone) was given intravenously to 21 children with the following acute bacterial infections; 13 cases of bronchopneumonia, 2 cases of urinary tract infection, 1 case of subcutaneous abscess, 1 case of cervical purulent lymphadenitis and acute tonsillitis, and 4 cases of acute bronchitis. Clinical effectiveness was obtained in 20 cases out of 21 cases and bacteriological effectiveness in 7 cases out of 8 cases. As for the side effects, 1 patient had asymptomatic eosinophilia, but no other laboratory abnormalities were observed. Above results suggest that T-1982 is a useful antibiotic for treating pediatric patients with various kinds of bacterial infections.

Anti-Bacterial Agents↗
PubMed1983

[Clinical experience with an ampicillin suppository (KS-R1) in pediatrics].

Ampicillin suppository (KS-R1) was given to 16 children with the following acute bacterial infection; 4 cases of acute pharyngitis, 2 cases of acute tonsillitis, 5 cases of acute bronchitis, 4 cases of bronchopneumonia, 1 case of group A beta-streptococcal infection. Out of 16 patients, good clinical responses were obtained in 16 patients, and bacteriological effectiveness was seen in all 3 cases. Side effects with KS-R1 were observed in 4 cases: 3 cases were perianal redness, and 4 cases were soft stool. From the above clinical results, KS-R1 is useful antibiotic suppository for treating the pediatric patients with various kinds of bacterial infections.

Age Factors↗