Biomedical subjects

T Nakamuro

Publications and source records attributed to T Nakamuro.

21 records · Page 2Linked to original sources

PubMed1989

[The kinesiological, chemical and pathological analysis in pulsed magnetic stimulation to the brain].

Pulsed magnetic stimulation of the human brain and spinal region has been reported recently. Unlike electrical stimulation, magnetic stimulation excites the motor cortex without discomfort to the subject. This method will be used as a new clinical test to study the central motor pathway. Although no deleterious effects have been observed thus far, the safety of this technique is regarded as unproven. We have investigated kinesiological, neurochemical and pathological analysis. Our pulsed magnetic discharge system consists of a high voltage capacitor bank and flat circular coil of insulated copper wire. The high voltage capacitor bank has a maximum voltage of 900 V, a maximum current flow of 8,000 amp and 1,637 uF in condenser capacitance. Sixty four normal wistar rats each weighing 200 g were used in this study. The rats were separated into two groups. Rats in one group received pulsed magnetic stimulation 50 times in 0.5 Hz by a flat circular coil which surrounded the head of rat at 1 cm in front of the interauricular line. The rats were housed in a long circular chamber. Rats in the other group did not receive the pulsed magnetic stimulation in the long circular chamber. The details of kinesiological analysis by Animex II measurement were described in an other paper (Act Neurologica Scandinavica 73; 352-358, 1986). The measurement of monoamines, dopamine (DA), homovalinic acid (HVA), noradrenaline (NA), and 5-hydroxytryptamine (5-HT), were made according to the Mefford's method 1 hour and 4 days after the magnetic stimulation. The analysis of the pathological state was also studied 1 hour and 4 days after the magnetic stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

[Electrophysiological studies in siblings of De Sanctis-Cacchione syndrome].

Multi-modality evoked potentials in two cases, who were siblings, of De Sanctis-Cacchione syndrome were reported. The case 1, who was elder sister of the case 2, was a 25-year-old female. And the case 2 was a 23-year-old female. They have the history of consanguinity. They were first noted to have skin erythema on exposure to sunlight, and a diagnosis of xeroderma pigmentosum was made. At the childhood neurological manifestation, such as mental retardation, deafness and muscular weakness developed gradually. The case 2, who was a elder sister, was operated on for squamous cell carcinoma of the eyelid at the age of 20 and 21 years old. Motor conduction velocity obtained from lower limbs were severely reduced and that from upper limbs were moderately delayed. Sensory conduction velocity of median nerve were severely diminished. Auditory brainstem responses (ABR) of the case 1 showed the prolongation in interpeak latency of I-V. ABR of the case 2 could not be obtained. N19 and N13 of short-latency somatosensory evoked potentials (SSEP) to median nerve stimulation with case 2 could not be obtained too. N13-N19 latency of case 1 was remarkably prolonged compared to the normal subjects. Central motor conduction time (CMCT) was studied in case 2 by using the magnetic stimulator. CMCT of case 2 was within the upper limit of normal control. Interpeak latency of I-V in ABR represents the brainstem dysfunction in auditory pathway, and interpeak latency of N13-N19 in SSEP was recognized as central conduction time from medial lemniscus to primary sensory area of cortex. So the prolongation of these interpeak latency in this cases may mean the dysfunction in the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

[A case of juvenile-type distal and segmental muscular atrophy of upper extremities (Hirayama disease) with the isolated cervical fusion at the C3-C4 levels].

The case, 29-year-old male, had suffered from muscular weakness and atrophy of the bilateral forearms and hands with tremor of the bilateral fingers for about 13 years. A neurological examination showed normal muscle-stretch reflexes and no sensory disturbances. A cervical spinogram revealed a fusion at the C3-C4 levels and mild spondylotic changes. We clinically diagnosed him as juvenile-type distal and segmental muscular atrophy of upper extremities (Hirayama disease) with the isolated congenital cervical fusion. Magnetic resonance imaging demonstrated an enlargement of the anterior epidural space from the C4-C5 levels to the Th 1-Th 2 levels. This abnormal epidural space showed relatively high signal intensity partially with low signal intensity on the T2 weighted spin-echo image and decreased in signal on the T1 weighted spin-echo image. And the dural sac was shifted backward and narrowed. And the soft discs was slightly protruded at the level of C4-5, C5-6 and C6-7. These findings suggest the over swelling and the delayed blood flow of the internal vertebral venous plexus. In this case, the degeneration of the cervical spine and soft disc derived from the congenital cervical fusion seems to have caused the internal vertebral venous plexus congestion and then have damaged the anterior horn cells.

Adult↗