PubMed Health⌕ Search

Biomedical subjects

I Hamada

Publications and source records attributed to I Hamada.

At least 37 records · Page 2Linked to original sources
PubMed1983

Familial clustering of situs inversus totalis, and asplenia and polysplenia syndromes.

We report on a family in which a male infant had the asplenia syndrome, a younger brother had the polysplenia syndrome, and their father had situs inversus totalis. The occurrence of the asplenia and the polysplenia syndromes in a sibship of the present family and in two other previously reported sibships indicates that the two syndromes are causally and pathogenetically related to each other. If it is assumed that the father had an incomplete form of the polysplenia complex, then the condition in this family either is an autosomal dominant trait or is multifactorially determined.

Adult↗
PubMed1983

Activities of single precentral neurons of the monkey during different tasks of forelimb movements.

The neuronal activity in the motor cortex of the rhesus monkey was investigated in three different tasks performed with finger, wrist, and arm movements. A total of 125 neuronal activities were analysed. They were classified into five groups in terms of muscular contractions provoked by intracortical stimulation; neurons related to contractions of finger, wrist, elbow, shoulder, or trunk muscles. The neuronal activities in three tasks performed with finger, wrist, or arm movements were investigated for each group. Most of the neurons related to the contractions of elbow, shoulder, or trunk muscles were associated solely with arm movement. Smaller numbers of neuronal activities changed their firing frequencies in association with two or three tasks. Neurons related to the contractions of finger and wrist muscles showed various firing patterns in the three tasks; some responded to a single task with wrist or arm movement, while others changed their activities in association with more than one task. The presence of multi-task related neurons is discussed with respect to the multisegmental termination of corticospinal axons in the spinal cord.

Animals↗
PubMed1981

Characteristics of the ipsilateral movement-related neuron in the motor cortex of the monkey.

The characteristics of the precentral neuron activity related to ipsilateral movements were studied while the monkey was performing finger, wrist and arm movements on either side. Out of 197 task-related neurons, 134 discharged in association with contralateral movements, but not with any one of 3 ipsilateral movements. Fifty neurons discharged with bilateral movements. Thirteen neurons discharged in association with ipsilateral movements (ipsi-neurons). Ten were recorded from the trunk or shoulder area of the motor cortex and were accompanied by contraction of those muscles by intracortical stimulation (ICS). The remaining 3 were related to elbow or wrist, but no ipsi-neurons were related to finger muscle contractions. In ipsilateral task performance, 7 ipsi-neurons discharged in association with finger and/or wrist movements in addition to arm movement. Five others were associated with arm movement. The last one discharged with wrist movement. Most of the units showed similar response to contralateral movement. Ipsi-neurons were classified into two groups. One group was recorded around the sulcus precentralis superior, had the lower threshold current and was mostly associated with finger, wrist and arm movements. The other was recorded in the rostral motor cortex, and had the higher threshold current and was related to arm movement. Among 185 neurons to which pyramidal tract stimulation was delivered, 2 out of the 80 PTNs and 11 out of the 105 non-PTNs were ipsi-neurons. EMGs were recorded from various muscles involved in the forelimb movements. Arm and finger muscles showed no activity when the monkey used the ipsilateral hand, while most of the shoulder and trunk muscles showed tonic or moderate transient changes in the activity during the ipsilateral tasks. The ipsi-neuron activity was discussed in consideration with EMGs.

Animals↗
PubMed1981

Intracellular activity and morphology of the prefrontal neurons related to visual attention task in behaving monkeys.

Neurons of the prefrontal-premotor cortex, which had been studied electorophysiologically during a modified reaction time task, were identified by intracellular pressure micro-injection of horseradish peroxidase (HRP). The cells were classified into those showing a sustained vs. transient change in activity during performance of the task. Cells showing a sustained response were found to have their somata in layers III and VI and cells showing transient responses were found to have their somata in layers II and III. All cells were pyramidal cells with spiny dendrites.

Afferent Pathways↗
PubMed1980

Antidromic latency of the monkey pyramidal tract neuron related to ipsilateral hand movements.

During three different motor tasks of finger, wrist and arm movements on either side, 80 pyramidal tract neuron (PTN) activities were recorded in the monkey motor cortex. They were divided into three groups; PTNs related to contralateral movement (contra-PTNs), those related to ipsilateral and contralateral movement (bilateral-PTNs) and those related to ipsilateral movement (ipsi-PTNs). The latency histogram of the antidromic activation was similar for contra-PTNs as well as ipsi- and bilateral-PTNs in the fast PTN group, but most of slow PTNs appeared among contra-PTNs. Intracortical microstimulation (ICMS) was delivered to correlate muscular contraction with PTN activity. Most of slow PTNs were related to proximal muscular contraction and PTNs related to proximal muscles appeared more in ipsi- and bilateral-PTNs than in contra-PTNs.

Animals↗
PubMed1980

Topographical projections from the prefrontal cortex to the post-arcuate area in the rhesus monkey, studied by retrograde axonal transport of horseradish peroxidase.

The cells of origin of ipsilateral, prefrontal cortical projections to the post-arcuate area were studied in rhesus monkeys with the horseradish peroxidase (HRP) method. Following injections of HRP into the dorsal portion of the post-arcuate area, retrogradely labeled cells appeared in the arcuate area dorsal to the principal sulcus, while, following injections into its ventral portion, labeled cells appeared in the arcuate area ventral to the principal sulcus. They were pyramidal cells and lay mainly in the III layer, but small numbers of them were also found in the IV and V layers. In addition, HRP labeled cells were seen ipsilaterally in the banks of the cingulate sulcus.

Animals↗
PubMed1979

[Clinical study of CS-1170 in children (author's transl)].

CS-1170 was administered to 9 cases of the pediatric field. The clinical effect was good in 6 cases, fair in 2, and poor in one. The doses ranged from 80 mg/kg to 100 mg/kg, and an intravenous injection of 300 mg/kg was given in only one case. In the poor case, continuous instillation of 100 mg/kg was given. In the 2 fair cases, the patients with septicemia received 80 mg/kg and 300 mg/kg, respectively. There was no improvement in clinical findings, but the bacteria alone disappeared. As side effects, vasalgia due to intravenous injection was observed in 2 cases, but it disappared by the intravenous injection of 500 mg dissolved in 10 ml. No case showed eruption, diarrhea, or acidophilia. GOT or GPT increased in no case either.

Age Factors↗
PubMed1978

Visual tracking and neuron activity in the post-arcuate area in monkeys.

1. A visual tracking task from a predetermined zone to another predetermined zone with use of a hand was trained in 3 macaque monkeys. They rotated the handle at the wrist joint by flexing or extending. A total of 88 neurons in the posterior bank of the arcuate sulcus, contralateral to the hand used, was related to the task. These neurons were designated as (post-arcuate-) FB neurons, following von Bonin and Bailey's terminology. 2. The FB neurons were classified into 4 types according to their discharge patterns during the task; (1) non-reciprocally, visually coupled neurons (6 neurons); (2) non-reciprocally movement-coupled neurons (41 neurons); (3) reciprocally movement-coupled neurons (17 flexion type and 8 extension type); and (4) finally, non reciprocally movement-coupled depression type neurons (15 neurons). These activations started before the movement onset, as detected in the displacement trace, and were not correlated to the EOG. 3. A possible functional significance of these neurons was discussed. A suggestion was made that in the FB area, after receiving the visual cue information, a function for the later movement direction and tis initiation are produced and sent to the motor apparatus within the brain so that effective tracking task can be performed.

Animals↗
PubMed1978

Precentral neuron activity associated with ipsilateral forelimb movements in monkeys.

Unit activity was recorded in motor cortex on one side, while monkeys were moving left or right fingers, wrists, or arms. On hundred and eighty five movement-related neurons were obtained from two monkeys. Of these, 122 were related to contralateral movements, 50 were to movements of both sides, and the remaining 13 to ipsilateral movements. It was found that ipsilateral-movement-related neurons tended to appear in groups of neurons that were related more to arm movements than to finger and/or wrist movements.

Action Potentials↗