1.Influence of precontraction of an agonist muscle on CNV and H reflex during the fixed foreperiod of a motor action. Different amount of the precontraction.
MASAKI FUMOTO ; YOSHIAKI NISHIHIRA ; TATSUO MIYA ; ARIHIRO HATTA ; MASAHIRO SHIMODA
Japanese Journal of Physical Fitness and Sports Medicine 1999;48(5):569-581
This study was carried out to investigate the influence of pre-movement tonic contraction on the Contingent Negative Variation (CNV) and Flexor Carpi Radialis (FCR) H reflex between the warning (WS) and response signal (RS) (foreperiod : FP) . Two levels of contraction were designed and the accompanying FCR Electromyography (EMG) was directly returned to the subject to sustain constant contraction. The subjects were 10 normal volunteers. Either small or middle (7.9±5.6% or 16.0±6.3% of the standard FCR EMG) contraction was sustained and the isometric wrist flexion movement was performed as quickly as possible following the RS.
EMG Reaction time (RT) in the small contracting condition was shorter than that in the resting condition (nothing performed during the foreperiod) in almost all subjects, but in the middle contracting condition EMG RT was not similar. The CNV amplitude for the late period of the FP, which was considered to be related to the motor preparation, was larger in the middle contracting condition than in the resting condition, although the small contracting condition was similar to the resting condition. The H reflex amplitude for the late period of the FP tended to be smaller than the control level in the small and middle contracting conditions, but it was not significant. However, in over half of the subjects, whose CNV amplitude for the late period of the FP increased linearly depending on the conditions, the H reflex amplitude was smaller than the control level in both contracting conditions, but it was not linear. These results indicate that the modulation of the EMG RT was not directly associated with the CNV or H reflex amplitudes for the late period of the FP, and a functional difference in the set for the RS between the spinal and the upper level of the central nervous system was present.
2.MORPHOLOGICAL AND STRUCTURAL CHARACTERISTICS OF THE PERITONEAL LYMPHATIC CAPILLARY NETWORKS
Ruicheng JI ; Masahiro MIURA ; Hiroshi SHIMODA ; Seiji KATO ;
Acta Anatomica Sinica 1955;0(03):-
Objective Peritoneal lymphatic features are studied to provide necessary data for understanding transport capabilities of the endothelial and mesothelial cells. Methods Enzyme\|histochemical staining methods were employed to investigate organization of the lymphatic networks and their endothelial ultrastructures in the monkey peritoneum using light,scanning and transmission electron microscopy. Results 5' Nase positive initial lymphatics showed extensive network,obvious valve like structures and numerous blind ends.The calibre of lymphatics with extremely irregular lumen varied greatly from 40 to 120?m.Lymphatic endothelium was usually separated from mesothelium by a small quantity of loose connective tissue,or they directly contacted each other in some areas.No basal lamina occurred between the peritoneum and the lymphatics originating from milky spots in the omentum and mesovarium.Milky spots are oval or round visible bodies aggregated by macrophages and lymphocytes.Both the endothelium of lymphatic lacunae and the mesothelium that forms the peritoneal stomata,represent a strong 5' Nase activity.Abundant microfibrils attached the stomatal edge. Conclusion The distribution and structure of peritoneal initial lymphatics reveal significant regional variations,and lymphatic endothelium has a close morphological and functional relationship with the mesothelium. [
3.Effect of alcohol intake on microvascular and EEG responses to cold water stimulation. .DELTA.DPG and EEG power spectral analysis.
MASAHIRO SHIMODA ; ARIHIRO HATTA ; JUN-ICHI SUZUKI ; JUN-ICHI MAEDA ; YOSHIAKI NISHIHIRA ; TAKASHI TAKEMIYA
Japanese Journal of Physical Fitness and Sports Medicine 1996;45(3):377-386
In this study, we examined changes in the amplitude of differential digital photoplethysmogram (ΔDPG) and the power spectral changes of EEG at rest during cold water immersion of the contralateral fingers (2°C), and after alcohol intake (0.3 g/kg) in 8 male subjects. This experiment showed that the ΔDPG amplitude decreased at rest and finger blood pressure was increased during the cold water stimulation, but there was no signifincant change in heart rate and EEG power spectrum. On chronological measurements for 30 minutes after alcohol intake, ΔDPG amplitude decreased slightly and finger blood pressure increased. Heart rate also tended to increase, and the alpha 1 power (8.0-9.8 Hz) on EEG gradually increased. The ODPG and finger blood pressure responses to cold water stimulation every 10 minutes was decreased after alcohol intake, whereas heart rate was not affected. However, a decrease in the alphal power after stimulation was revealed. From these results, it may be concluded that during 5-10 s of cold water stimulation, increased skin sympathetic nerve activity was one of the factors that raises blood pressure.
4.The change of event-related potentials with choice task.
ARIHIRO HATTA ; YOSHIAKI NISHIHIRA ; MASAHIRO SHIMODA ; MASAKI FUMOTO ; HITOSHI IKEDA ; TAKASHI TAKEMIYA
Japanese Journal of Physical Fitness and Sports Medicine 1997;46(4):405-413
Event-related potentials (ERPs) were recorded from 9 normal subjects engaged in a somatosensory target discrimination task. Subjects were instructed (1) to keep a mental count of each target or (2) to rotate a grip in the direction of abduction after each target stimulus using the right hand. Target stimuli were electrical pulses delivered randomly through ring electrodes to the left second digit with probabilities of 0.2, and nontarget stimuli were delivered to the left fifth digit with probabilities of 0.8.
P 100 was prominent in somatosensory tasks, and had a widespread distribution on the scalp without having any relation to kinds of tasks, therefore, P 100 reflects the sensation of somatosensory stimulation. N 140 was largest at Fz in both counting and movement tasks, so our result supported the hypothesis that N 140 is generated in the frontal lobes regions. Moreover, N 140 latency was shorter during movement than during counting. These results indicate that N 140 is related to carrying out movement. P 300 was largest at Cz during counting, and largest at Pz and C4' during movement. These results also indicate that P 300 may have multiple intracerebral generators since P300 origin differs based on the kind of tasks or stimuli. In addition, the appearance of P300 after nontarget stimuli indicates that P 300 reflects a non-selective postdecision closure of cognitive activity. In conclusion, each component of ERPs may have a specific origin and specific characteristics.
5.Effects of 24-hours sleep deprivation on central information processing. Examination using event-related potentials (P300).
TAKESHI KANEDA ; YOSHIAKI NISHIHIRA ; ARIHIRO HATTA ; MASAHIRO SHIMODA ; MASAKI FUMOTO ; TAKASHI TAKEMIYA
Japanese Journal of Physical Fitness and Sports Medicine 1999;48(4):477-483
The purpose of this study was to investigate the effect of the sleep deprivation for central information processing. Therefore we examined the changes in the amplitude and the latency of P300 event-related potentials (ERPs) before and after sleep deprivation in eight subjects. In addition to P300, we examined the power spectral changes of the EEG and the R-R intervals at rest before ERP measurements. The subjects performed an auditory target discrimination task and were instructed to keep mental count of each target stimulus. Then 2000 Hz tones (target) and 1000 Hz tones (nontarget) were randomly presented with probabilities of 0.2 and 0.8.
P300 latency at Fz, Cz, C3 and C4 was significantly prolonged after sleep deprivation (p<0.05) . P300 amplitude at Cz after sleep deprivation was significantly smaller than before sleep deprivation (p<0.05) . Alpha 1 power (8-10 Hz) at Cz on EEG was significantly decreased after sleep deprivation, but no other bands changed on EEG. The R-R interval was also significantly extended after sleep deprivation. We concluded that both central information processing and the autonomic nervous system may be influenced by sleep deprivation.
6.Feature of event-related potentials in developing children.
TAKESHI KANEDA ; YOSHIAKI NISHIHIRA ; ARIHIRO HATTA ; MASAKI FUMOTO ; MASAHIRO SHIMODA ; SIN-ICHIRO TOKITOH ; SACHIYO AKIYAMA
Japanese Journal of Physical Fitness and Sports Medicine 2000;49(2):307-314
We examined here, changes in event-related potentials (ERPs) in eighteen children from 7 to 12 years and twelve adults. In addition to ERPs, we examined changes of EMG-RT. Subjects performed an auditory target discrimination task, in which 1000 Hz tones (target) and 2000 Hz tones (standard) were randomly presented with probabilities of 0.2 and 0.8.
We found P300 as most consistent component of ERPs since childhood. P300 latency and EMG-RT in children was significantly prolonged than in adults (p<0.01) . P300 amplitude in children was significantly larger than in adults (p<0.05) . We concluded that both stimulus evaluation time and response selection time in children are more prolonged than that in adults, although ERPs is confirmed in children.
7.EVENT-RELATED POTENTIALS (ERPs) AND LONG-TERM PHYSICAL EXERCISE
SACHIYO AKIYAMA ; YOSHIAKI NISHIHIRA ; ARIHIRO HATTA ; MASAKI FUMOTO ; TAKESHI KANEDA ; SHINICHIROU TOKITOU ; MASAHIRO SHIMODA
Japanese Journal of Physical Fitness and Sports Medicine 2000;49(2):267-276
Electrophysiologic effects of physical exercise were investigated by comparing a training group and non-training group. ERPs were recorded by oddball paradigm using auditory stimuli as well as count and reaction tasks. EMG-RT was recorded during the reaction task. No reliable exercise effects on N100 amplitudes or latencies were observed. Concerning P300 amplitudes, no significant difference between the training group and non-training group was seen although P300 latencies of the training group were significantly shorter than those of the non-training group in the count task. Moreover, EMG-RT of the training group was significantly shorter than that of the non-training group.
These findings suggest that the long-term physical exercise improved the efficiency of informa-tion processing and superior cognitive function in the brain.
8.A Case of Sigmoid Colon Cancer Detected in Process of Virchow Lymph Node Metastasis
Momotaro MUTO ; Mizue SHIMODA ; Chisato ISHIKAWA ; Mitsutaka INOUE ; Hiroyuki TAKAHASHI ; Masahiro HAGIWARA ; Takanori AOKI ; Michinori HASHIMOTO ; Satoshi INABA ; Hidehiko YABUKI
Journal of the Japanese Association of Rural Medicine 2013;62(2):140-145
This report takes up a 65-year-old woman. Suspecting a tumorous superior fovea in the left clavicle, she consulted with our hospital’s Department of Otolaryngology. As a result of the lymph node biopsy performed at the department, she was diagnosed as having moderately differentiated tubular carcinoma. CT scanning revealed a number of swollen lymph nodes and parietal tylosis in the sigmoid colon. Endoscopy produced no abnormalities in the upper digestive tract, but an endoscopic check of the lower digestive tract revealed an all-around Type II tumor. The ailment was pathohistologically identified as tubular carcinoma. That said, the patient was diagnosed as suffering from sigmoid colon accompanying Virchow lymph node metastasis. Then, sigmoidostomy and the dissection of the D3 lymph node were performed. Pathohistological diagnosis revealed moderately differentiated tubular carcinoma, SE, N3, HO, PO, M1 (Virchow lymph node metastasis), Stage IV. Chemotherapy was postoperatively initiated with mFOLFOX6.
9.Torsion of the Gallbladder:A Case Report
Momotaro MUTO ; Masayo YAMAMOTO ; Mizue SHIMODA ; Akihiro HAYASHI ; Senri ISHIKAWA ; Mitsutaka INOUE ; Hiroyuki TAKAHASHI ; Masahiro HAGIWARA ; Takanori AOKI ; Michinori HASHIMOTO ; Satoshi INABA ; Hidehiko YABUKI
Journal of the Japanese Association of Rural Medicine 2012;61(2):124-129
A 86-year-old woman visited us, complaining about sharp abdominal pain she had very morning when she got up. Ultrasound and computer tomography scans of the abdomen revealed notable parietal hypertrophy and swelling of the gallbladder. The old woman was diagnosed with acute cholecystitis and immediately admitted to the hospital. Her condition did not improve on conservative management. Percutaneous transhepatic gallbladder drainage (PTGBD) was performed. The bile thus aspirated was bloody, which led us to suspect necrotizing cholecystitis. Emergency cholecystectomy was done. The abdominal operation found the gallbladder wandering with a torsion of 360 degrees around the gallbladder neck as the axis and the leakage of bile in the abdominal cavity from what could be presumed to be the area where the PTGBD was placed. After the torsion was corrected, the gallbladder was surgically removed. Neither gallstones nor tumors were found in it. There were signs of hemorrhagic necrosis in the mucus membrane. The patient made good progress after the operation and was discharged on the 15th hospital day. Torsion of the gallbladder is a comparatively rare entity and its symptoms are not always specific. Therefore, it defies preoperative diagnosis. In this paper, we report our experience with a case of this disease which presented characteristic radiographic images and discuss the treatment strategies including PTGBD.
10.The Attempt to Develop a "Model Program" on the Basis of the Objectives Established by the Ministry of Health, Labour and Welfare in the New Postgraduate Clinical Training System
Kazuhiko KIKAWA ; Masahiro TANABE ; Kiyoshi KITAMURA ; Hayato KUSAKA ; Masamune SHIMO ; Katsusada TAKAHASHI ; Yujiro TANAKA ; Tadashi MATSUMURA ; Takao MORITA ; Kunihiko MATSUI ; Takashi OHBA ; Hirotsugu KOHROGI ; Osamu SHIMODA ; Taichi TAKEDA ; Junichi TANIGUCHI ; Tatsuya TSUJI ; Hiroyuki HATA
Medical Education 2006;37(6):367-375
Clinical training programs play an extremely important role in the new postgraduate clinical training system introduced in 2004 because facilities for clinical training now include various health-related institutions in addition to the university hospitals and special hospitals for clinical training used in the previous system. Although educational goals have been established by the Ministry of Health, Labour and Welfare, trainees may have difficulty achieving these goals, even under the guidance of staff at the various facilities. There are differences in the function and quality of health-related institutions in the community. For the practical and convenient application of educational goals, we have attempted develop a “model program” to supplement the objectives indicated by the learning goals with more specific objectives. These supplementary objectives can be modified by individual institutions. We hope that this “model program” contributes to the development of objectives for each institution and helps improve the quality of the postgraduate training system in Japan.