Biomedical subjects

Toshiro Fujimoto

Publications and source records attributed to Toshiro Fujimoto.

5 recordsLinked to original sources

PubMed2006

Abnormal glucose metabolism in the anterior cingulate cortex in patients with schizophrenia.

Changes in glucose metabolism were studied in the brains of schizophrenic patients treated with neuroleptics, using [(18)F]fluoro-deoxy-glucose positron emission tomography (FDG-PET). Fourteen male and eight female patients in their thirties and forties were studied in a resting state. Data from FDG-PET were processed with an anatomic standardization method, three-dimensional stereotactic surface projections (3D-SSP), which provided relative glucose metabolic values that mitigated the contamination of brain atrophy. Z-score maps indicating metabolic differences between the patient and control groups were also acquired. Metabolic values in 19 regions were evaluated in the right and left hemispheres. Patients showed decreased values in the frontal cortex, primary sensory regions and anterior cingulate cortex, more in the rostral affective subdivision than the dorsal cognitive subdivision in both hemispheres, and increased metabolic values in left and right basal ganglia, left temporal and right medial parietal regions. Values were more decreased in both anterior cingulate regions, and more increased in the right thalamus in male than female patients, suggesting gender-related dysfunction in the anterior cingulate and thalamus in schizophrenia. FDG-PET demonstrated that schizophrenia may be a disorder with a dysfunction of fronto-striatal-thalamic circuitry including the cingulate cortex.

Adult↗

PubMed2006

Improving the accuracy of pedometer used by the elderly with the FFT algorithm.

PURPOSE: The aim of this study was to investigate and improve the accuracy of accelerometer-type pedometers used by the elderly with slow walking speeds, with or without gait disorders, who do or do not use a cane. METHODS: Eighteen subjects walked with a cane (5 males, 13 females; age, 80.9 +/- 7.7 yr; height, 148.1 +/- 7.7 cm; weight, 51.8 +/- 8.8 kg (mean +/- SD); nine had impaired gait), and 31 subjects walked without a cane (7 males, 24 females; age, 80.9 +/- 7.7 yr; height, 148.1 +/- 7.7 cm; weight, 51.8 +/- 8.8 kg; 15 had impaired gait). Subjects walked for approximately 20 m (10 m in each direction and a turning arc) at their own speed. We determined the number of steps by pedometer (PM), by visually counting the actual number of steps (RM), and by the triaxial acceleration signals. The power spectrum of the accelerometer in each direction calculated by fast Fourier transform (FFT) for a 4-s temporal window was normalized with the maximum power of each window. It was composited, and the frequency at maximum power was considered as the cadence. The number of steps taken (FM) was determined by summing all the estimated steps in each window. RESULTS: PM was significantly less than the RM (P < 0.05), and the error of PM was 53.2 +/- 34.1% of RM. FM did not differ from the RM, and the average error of FM was -0.7 +/- 7.9% of RM (absolute value: 5.8 +/- 5.3%). CONCLUSION: We suggest that our FFT method is suitable for estimating the number of steps during walking in this population.

Acceleration↗

PubMed2004

Fractal dynamics of body motion in patients with Parkinson's disease.

In this paper, we assess the complexity (fractal measure) of body motion during walking in patients with Parkinson's disease. The body motion of 11 patients with Parkinson's disease and 10 healthy elderly subjects was recorded using a triaxial accelerometry technique. A triaxial accelerometer was attached to the lumbar region. An assessment of the complexity of body motion was made using a maximum-likelihood-estimator-based fractal analysis method. Our data suggest that the fractal measures of the body motion of patients with Parkinson's disease are higher than those of healthy elderly subjects. These results were statistically different in the X (anteroposterior), Y (lateral) and Z (vertical) directions of body motion between patients with Parkinson's disease and the healthy elderly subjects (p < 0.01 in X and Z directions and p < 0.05 in Y direction). The complexity (fractal measure) of body motion can be useful to assess and monitor the output from the motor system during walking in clinical practice.

Acceleration↗

PubMed2002

Imaging saponin-induced structural changes in neural processes with atomic force microscopy.

Temporal changes in the structure of neuronal processes in the presence of saponin were studied by atomic force microscopy in a fluid medium. After saponin treatment, concavities were formed on the surface of some neurites and fibrous structures in other neurites were splayed. The vertical height of these splayed fibrils or fibrillar bundles ranged from 13 to 370 nm, and the horizontal width was less than 500 nm. These findings suggest that formation of concavities and separation of bundled fibrils occurred simultaneously in saponin-treated neurites.

Animals↗

PubMed2002

Discrimination of walking patterns using wavelet-based fractal analysis.

In this paper, we attempted to classify the acceleration signals for walking along a corridor and on stairs by using the wavelet-based fractal analysis method. In addition, the wavelet-based fractal analysis method was used to evaluate the gait of elderly subjects and patients with Parkinson's disease. The triaxial acceleration signals were measured close to the center of gravity of the body while the subject walked along a corridor and up and down stairs continuously. Signal measurements were recorded from 10 healthy young subjects and 11 elderly subjects. For comparison, two patients with Parkinson's disease participated in the level walking. The acceleration signal in each direction was decomposed to seven detailed signals at different wavelet scales by using the discrete wavelet transform. The variances of detailed signals at scales 7 to 1 were calculated. The fractal dimension of the acceleration signal was then estimated from the slope of the variance progression. The fractal dimensions were significantly different among the three types of walking for individual subjects (p < 0.01) and showed a high reproducibility. Our results suggest that the fractal dimensions are effective for classifying the walking types. Moreover, the fractal dimensions were significantly higher for the elderly subjects than for the young subjects (p < 0.01). For the patients with Parkinson's disease, the fractal dimensions tended to be higher than those of healthy subjects. These results suggest that the acceleration signals change into a more complex pattern with aging and with Parkinson's disease, and the fractal dimension can be used to evaluate the gait of elderly subjects and patients with Parkinson's disease.

Acceleration↗