1.Effects of aging on force adaptation during manipulation of a small object using a precision grip.
SATORU KAWAI ; HAYATO TSUDA ; HIROSHI KINOSHITA ; KOMEI IKUTA ; KEN HASHIZUME ; TOMOHIKO MURASE ; TAKASHI YAMAMOTO
Japanese Journal of Physical Fitness and Sports Medicine 1997;46(5):501-512
The effects of aging on adaptive force control of precision grip while manipulating a small object were compared between older (84.2±8.9 yrs, n=33) and young adults (19.1±0.24 yrs, n=18) from the following perspectives: (1) adaptation to an unfamiliar object with uncertain physical properties during 16 consecutive lifts ; (2) adaptation to an object with a non-slippery (sandpaper) surface during 12 consecutive lifts, followed by 12 consecutive lifts with a slippery (silk) surface ; and (3) adaptation to objects with different weights (0.49, 0.98, 1.96 and 2.94 N) during 24 lifts (6 consecutive lifts for each weight) .During each trial, grip and load forces were monitored. Safety margin force and slip force were evaluated from the data obtained.
The majority of older adults employed a considerably greater safety margin for an unfamiliar object in the initial trials than did young adults, while the minority of the older adults were able to adapt their safety margin force with a few trials, like the young adults. The older adults who overestimated the safety margin force, however, successfully adjusted their grip force to more optimal levels with repeated lifts, suggesting that the adaptive capability of grip force remained even at 90 years of age. The adaptation of older adults, however, was found to be slower (i. e., required more trials) than that of young adults. Upon encountering surface friction change, the safety margin forces in older adults were more strongly affected by the previous surface condition than those in the young adults. In addition, adaptation to a non-slippery surface seemed more difficult than that to a slippery surface with aging. Upon encountering weight change, older adults showed more difficulties in scaling their safety margin forces according to object weights.
Slower adaptation and difficulty in adaptation to the friction or weight change in older adults may reflect the agerelated decline of tactile sensitivity which impaired the signaling of frictional conditions and various discrete events in the hand. In addition, the lift repetition for force adaptation may possibly reflect the age-related deficit or slowing of central processing capacities related to grip force production.
2.Electromyographic Changes Induced by Caloric Stimulation of the Semicircular Canals and by Neck Movement. Investigation of the F wave on the evoked electromyograms of the upper extremity and the surface electromyograms of the posterior cervical region.
Nobuyoshi KOIWA ; Kazuki TOKORO ; Masahide MACHIDA ; Taichi TABATA ; Okuto KIMURA ; Tomohiko YAMAMOTO ; Shin TORISAWA ; Takeshi KUSUMI ; Naohiko WATANABE
Journal of the Japan Society of Acupuncture and Moxibustion 2000;50(3):439-449
We assumed that changes in the excitability of motor nerves play some role in the stiffness of the neck, shoulders, and extremities in patients with vertigo. To obtain a better understanding of this phenomenon, we stimulated the receptors involved in body equilibrium with external stimuli, i.e., 1) caloric stimulation of the semicircular canals and 2) neck movements, and investigated changes in the F wave and the surface electromyogram (S-EMG) of the posterior cervical region.
The subjects were 40 healthy adults. Caloric stimulation of the semicircular canals was performed by infusing15°C water, and changes in the F wave examined. In addition, changes in the S-EMG by stimulation at temperatures of 5°C or 44°C were investigated. We examined changes in the F wave by the neck movements in association with theresults of the blindfold ed vertical writing test. The F wave of a patient with vertigo was also examined.
During vertigo induced by caloric stimulation of the semicircular canals, the excitability of the F wave on both the stimulated and non-stimulated sides increased, the S-EMGs showed decreased excitability on both the stimulated and non-stimulated sides during maximum voluntary contraction in the subject who experienced severe vertigo, nystagmus, and nausea. The changes in the F wave induced by the neck movements were small. However, excitability increased more significantly during posterior flexion than during other movements, and the angle of deviation of the letters written blindly tended to deviate most markedly toward the left during posterior flexion. The F wave of the patient with vertigo showed excitability, but it tended to decrease as the vertigo diminished.
These findings suggest that vertigo is accompanied by changes in the excitability of motor nerves. These changes are somehow related to the muscle stiffening that results from vertigo.
3.Upregulation of macrophage migration inhibitory factor and calgizzarin by androgen in TM4 mouse Sertoli cells.
Hiroyuki KASUMI ; Shinji KOMORI ; Kazuko SAKATA ; Naoko YAMAMOTO ; Tomohiko YAMASAKI ; Yonehiro KANEMURA ; Koji KOYAMA
Asian Journal of Andrology 2006;8(5):549-554
AIMTo identify proteins induced by androgen in Sertoli cells during spermatogenesis.
METHODSWe analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone (DHT) using surface enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS).
RESULTSWe found increases in the expression of a 5.0-kDa protein at 15 min, an 11.3-kDa protein at 24 h and 4.3 kDa, 5.7 kDa, 5.8 kDa, 9.95 kDa and 9.98 kDa proteins at 48 h after the treatment. In contrast, the expression of 6.3 kDa and 8.6 kDa proteins decreased at 30 min, and 4.9 kDa, 5.0 kDa, 12.4 kDa and 19.8 kDa proteins at 48 h after the treatment. The 11.3-kDa protein was identified as macrophage migration inhibitory factor (MIF) known to having various functions. The 9.98-kDa protein was identified as calgizzarin related to calcium channels. The timing of their expression suggests that MIF and calgizzarin are involved in late regulation of spermatogenesis in Sertoli cells by androgen.
CONCLUSIONMIF and calgizzarin are two important androgen-responsive proteins produced by Sertoli cells and they might play a role in regulating spermatogenesis.
Androgens ; pharmacology ; Animals ; Cell Line ; Dihydrotestosterone ; pharmacology ; Gene Expression Regulation ; drug effects ; Kinetics ; Macrophage Migration-Inhibitory Factors ; genetics ; Male ; Mice ; Protein Array Analysis ; S100 Proteins ; genetics ; Sertoli Cells ; drug effects ; physiology ; Spermatogenesis
4.The isolation and identification of apolipoprotein C-I in hormone-refractory prostate cancer using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry.
Kaori YAMAMOTO-ISHIKAWA ; Hiroyoshi SUZUKI ; Masahiko NEZU ; Naoto KAMIYA ; Takashi IMAMOTO ; Akira KOMIYA ; Kazuyuki SOGAWA ; Takeshi TOMONAGA ; Fumio NOMURA ; Tomohiko ICHIKAWA
Asian Journal of Andrology 2009;11(3):299-307
Androgens play a central role in prostate cancer pathogenesis, and hence most of the patients respond to androgen deprivation therapies. However, patients tend to relapse with aggressive prostate cancer, which has been termed as hormone refractory. To identify the proteins that mediate progression to the hormone-refractory state, we used protein-chip technology for mass profiling of patients' sera. This study included 16 patients with metastatic hormone-refractory prostate cancer who were initially treated with androgen deprivation therapy. Serum samples were collected from each patient at five time points: point A, pre-treatment; point B, at the nadir of the prostate-specific antigen (PSA) level; point C, PSA failure; point D, the early hormone-refractory phase; and point E, the late hormone-refractory phase. Using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry, we performed protein mass profiling of the patients' sera and identified a 6 640-Da peak that increased with disease progression. Target proteins were partially purified, and by amino acid sequencing the peak was identified as a fragment of apolipoprotein C-I (ApoC-I). Serum ApoC-I protein levels increased with disease progression. On immunohistochemical analysis, the ApoC-I protein was found localized to the cytoplasm of the hormone-refractory cancer cells. In this study, we showed an increase in serum ApoC-I protein levels in prostate cancer patients during their progression to the hormone-refractory state, which suggests that ApoC-I protein is related to progression of prostate cancer. However, as the exact role of ApoC-I in prostate cancer pathogenesis is unclear, further research is required.
Aged
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Amino Acid Sequence
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Antineoplastic Agents, Hormonal
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therapeutic use
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Apolipoprotein C-I
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analysis
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blood
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isolation & purification
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Blotting, Western
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Cell Line
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Disease Progression
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Drug Resistance, Neoplasm
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Humans
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Immunohistochemistry
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Male
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Middle Aged
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Molecular Sequence Data
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Prognosis
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Prostatic Neoplasms
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drug therapy
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metabolism
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Protein Array Analysis
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Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
5.Endoscopic features of gastrointestinal stromal tumor in the small intestine
Yutaro IHARA ; Takehiro TORISU ; Tomohiko MORIYAMA ; Junji UMENO ; Atsushi HIRANO ; Yasuharu OKAMOTO ; Yoshifumi HORI ; Hidetaka YAMAMOTO ; Takanari KITAZONO ; Motohiro ESAKI
Intestinal Research 2019;17(3):398-403
BACKGROUND/AIMS: Gastrointestinal stromal tumor (GIST) is one of the most common types of submucosal tumors (SMTs). Because of GIST's malignant potential, it is crucial to differentiate it from other SMTs. The present study aimed to identify characteristic endoscopic findings of GISTs in the small intestine. METHODS: We reviewed the clinicopathological and endoscopic findings of 38 patients with endoscopically or surgically resected SMTs in the small intestine. SMTs were classified into GIST and non-GIST groups, and clinicopathological and endoscopic findings were compared between the 2 groups. RESULTS: Fifteen patients had GIST and 23 patients had other types of SMTs in the small intestine. Comparison of the endoscopic findings between the 2 groups revealed that dilated vessels in the surrounding mucosa were significantly more in number in the GIST group than in the non-GIST group (P<0.05). However, there were no other differences in endoscopic findings between the 2 groups. Among patients with GISTs, the presence of dilated vessels in the surrounding mucosa was not associated with bleeding risk, tumor size, or metastasis rate at diagnosis. CONCLUSIONS: Dilated vessels in the surrounding mucosa, identified during balloon-assisted endoscopy, may be a diagnostic indicator for GIST in the small intestine. However, its clinical significance should be further analyzed.
Diagnosis
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Endoscopy
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Gastrointestinal Stromal Tumors
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Hemorrhage
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Humans
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Intestine, Small
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Mucous Membrane
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Neoplasm Metastasis
6.Hybrid Aortic Repair for Visceral Aortic Patch Aneurysm after Thoracoabdominal Aortic Aneurysm Repair
Ryuki YAMADA ; Hideki UEDA ; Hiroki KONO ; Kaoru MATSUURA ; Michiko WATANABE ; Tomohiko INUI ; Yasunori YAKITA ; Yusuke SHIBATA ; Hiroaki YAMAMOTO ; Goro MATSUMIYA
Japanese Journal of Cardiovascular Surgery 2020;49(6):385-389
We report a 48-year-old man who underwent hybrid aortic repair for visceral aortic patch (VAP) aneurysm. He had undergone descending thoracic aortic repair for post-dissection aneurysm at the age of 25, ascending aorta and proximal aortic arch aneurysm repair at the age of 27, and residual thoracoabdominal dissecting aortic aneurysm repair with VAP reconstruction at the age of 28. During 20 years of follow-up, the VAP gradually enlarged and eventually reached 70×61 mm in diameter. Considering a possible severe adhesion after 2 previous left thoracotomies, we planned a 2-staged hybrid aortic repair. First, we performed reno-visceral debranching and as a second stage operation, endovascular aortic repair was performed successfully 39 days after the first-stage operation.