1.CHANGES IN THE MOTOR EVOKED POTENTIALS DURING REPETITIVE MAXIMUM PEDALING WITH DIFFERENT LOADS
MASASHI MITAMURA ; TAKASHI ENDOH ; REI TAKAHASHI ; TOMOYOSHI KOMIYAMA
Japanese Journal of Physical Fitness and Sports Medicine 2003;52(5):555-563
Eleven healthy subjects repetitively performed maximal cycling movement for 10 s with 20 s rest intervals. The load of the cycling was respectively set to 30% (high frequency task, lIF' task) and 80% (high power task, TIP task) of the optimal load for exerting maximum anaerobic power. Each task was finished when the exerted maximal power was decreased to 80% of the initial value. While performing each task, transcranial magnetic stimulation (TMS) was delivered to the motor cortex which was effectively able to evoke motor evoked potential (MEP) from the thigh muscles. Elec-tromyographic (EMG) activity of the left rectos femoris (RF), vastus lateralis (VL) and the MEP was analyzed.
The maximal power exerted was decreased to 80.6±1.58 % in the HF task, and 77.3±0.77 % in the HP task. The number of repeated sets in each task was 10.1 ± 1.45 (HF task) and 4.1±0.25 sets (HP task) . The MEP area of the RF and VL was not changed significantly in the HF task, though it was significantly increased in the latter half of the HP task. A two-way ANOVA showed that the time course of the changes in the MEP area was significant in the VL (p<0.01), but not in the RF. In both tasks, the duration of the MEP was progressively prolonged in each 10 sec pedaling, and the prolongation was evident in the latter half of the tasks. However, the magnitude of the prolongation was significantly larger during the HP task. The ratio of the integrated amplitude of the EMG and the exerted power at the initial 5 bouts of cycling (EMG/Power ratio) was significantly increased in both the RF and VL, suggesting that peripheral muscular fatigue was induced during at the latter half of each task. Furthermore, the EMG/Power ratio in the VL was significantly higher during the HP task than the HF task.
These results suggest that central fatigue plays a significant role in decreasing the maximum power output, and that it takes place in a muscle-dependent fashion. It was also suggested that during low load, but relatively higher cadence frequency, central fatigue other than that involving the motor cortex accounts for the decreased power output.
2.CENTRAL FATIGUE DURING CONSTANT CADENCE PEDALING FOR 60 SECONDS-A TRANSCRANIAL MAGNETIC STIMULATION STUDY
TAKASHI ENDOH ; MASASHI MITAMURA ; REI TAKAHASHI ; TOMOYOSHI KOMIYAMA
Japanese Journal of Physical Fitness and Sports Medicine 2003;52(5):565-574
Changes in the motor evoked potential (MEP) evoked by transcranial magnetic motor cortex stimulation (TMS) of rectos femoris (RF) and vastus lateralis (VL) was examined during constant cadence cycling tasks for 60 sec. Subjects were 11 normal male volunteers aged between 19 and 25 years. Pedaling load was set at 100% and 80% of the estimated optimal value for maximum anaerobic power output. For the low load task (LL task), the pedaling rate was set at half the value of the maximum pedaling rate with the load set at 80% of the optimal for maximum anaerobic power output. For the high load task (HL task), the pedaling rate was set such that the power was equivalent to the LL task.
The route mean square of the electromyographic (EMG) activity amplitude tended to steeply increase during the latter half of the task. The magnitude of the increase in the RMS was significantly larger in the HL task than the LL task. The area of the MEP also tended to increase in both tasks, though the degree of the increase was significantly larger in the LL task than the HL task. The EMG silent period (SP) after the MEP tended to steeply increase just after the task initiation and to decrease in the latter half of the task in the HL task. However, in the LL task the facilitation of MEP was not found, but it showed a gradual decrease while performing the task. The duration of the MEP tended to increase in both tasks, though the degree of the increase in the VL was significantly larger in the LL task than the HL task. The linear regression analysis between the size of the MEP and the background EMG shows a significant positive correlation coefficient during isometric contraction, but not during the two types of cycling tasks.
These results suggest that the neural circuit responsible for the MEP was controlled differentially during isometric contraction and constant cadence pedaling. Also it is likely that the mechanism of central fatigue differed depending on the cadence and or load in a task-dependent fashion irrespective of the same power output.
3.CENTRAL AND PERIPHERAL FATIGUE DURING SUSTAINED MAXIMAL VOLUNTARY CONTRACTIONS IN TRAINED AND UNTRAINED HUMAN SUBJECTS
TAKASHI ENDOH ; MASASHI MITAMURA ; TSUYOSHI NAKAJIMA ; REI TAKAHASHI ; TOMOYOSHI KOMIYAMA
Japanese Journal of Physical Fitness and Sports Medicine 2004;53(2):211-220
The present study investigated how resistance training affects behaviors related to central and peripheral fatigue during a sustained maximal voluntary contraction (MVC) . The subjects were well-trained (TR, n=8) and sedentary untrained (UT, n=6) males. The subjects were asked to repetitively perform 3 sets of MVC (elbow flexion) for 1 min with a rest interval of 1 min. Transcranial magnetic stimulation (TMS) was delivered to the contralateral motor cortex to evoke the motor evoked potential (MEP) and electromyographic (EMG) silent period (SP) after the MEP. Ratio of root mean square (RMS) of the EMG and elbow flexion force (RMS/F) was also calculated.
The time course of the decrease in elbow flexion force that was standardized with respect to the maximal value obtained at the beginning of the first MVC was almost identical in both TR and UT. At the end of the task, the elbow flexion force decreased to around 30 % of the initial value in both groups. Decrease in voluntary activation (VA) estimated by the increment of the force after TMS was significantly larger in UT (77.3%) than in TR (88.2%) at the end of the task. Although the increase in MEP during the first set was significantly greater in UT than in TR, elongation of SP was significantly larger in UT than in TR. Increase in RMS/F, which is a manifestation of peripheral fatigue, was significantly larger in TR than in UT.
These results suggest that decrease in MVC in UT and in TR is respectively more attributable to central and peripheral fatigue, and that inhibitory inputs to motor cortex were larger in UT than in TR. It is concluded that expression of central and peripheral fatigue is affected by resistance training.
4.Lymphadenectomy can be omitted for low-risk endometrial cancer based on preoperative assessments.
Takashi MITAMURA ; Hidemichi WATARI ; Yukiharu TODO ; Tatsuya KATO ; Yosuke KONNO ; Masayoshi HOSAKA ; Noriaki SAKURAGI
Journal of Gynecologic Oncology 2014;25(4):301-305
OBJECTIVE: According to the International Federation of Gynecology and Obstetrics staging, some surgeons perform lymphadenectomy in all patients with early stage endometrial cancer to enable the accurate staging. However, there are some risks to lymphadenectomy such as lower limb lymphedema. The aim of this study was to investigate whether preoperative assessment is useful to select the patients in whom lymphadenectomy can be safely omitted. METHODS: We evaluated the risk of lymph node metastasis (LNM) using LNM score (histological grade, tumor volume measured in magnetic resonance imaging [MRI], and serum CA-125), myometrial invasion and extrautrerine spread assessed by MRI. Fifty-six patients of which LNM score was 0 and myometrial invasion was less than 50% were consecutively enrolled in the study in which a lymphadenectomy was initially intended not to perform. We analyzed several histological findings and investigated the recurrence rate and overall survival. RESULTS: Fifty-one patients underwent surgery without lymphadenectomy. Five (8.9%) who had obvious myometrial invasion intraoperatively underwent systematic lymphadenectomy. One (1.8%) with endometrial cancer which was considered to arise from adenomyosis had para-aortic LNM. Negative predictive value of deep myometrial invasion was 96.4% (54/56). During the mean follow-up period of 55 months, one patient with deep myometrial invasion who refused an adjuvant therapy had tumor recurrence. The overall survival rate was 100% during the study period. CONCLUSION: This preoperative assessment is useful to select the early stage endometrial cancer patients without risk of LNM and to safely omit lymphadenectomy.
Adult
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Aged
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CA-125 Antigen/blood
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Endometrial Neoplasms/pathology/*surgery
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Female
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Humans
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*Lymph Node Excision
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Lymphatic Metastasis
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Magnetic Resonance Imaging/methods
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Middle Aged
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Neoplasm Invasiveness
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Neoplasm Recurrence, Local
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Neoplasm Staging
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Postoperative Care/methods
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Preoperative Care/methods
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Prognosis
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Survival Analysis
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Unnecessary Procedures
5.Multivariate survival analysis of the patients with recurrent endometrial cancer.
Tetsuji ODAGIRI ; Hidemichi WATARI ; Masayoshi HOSAKA ; Takashi MITAMURA ; Yousuke KONNO ; Tatsuya KATO ; Noriko KOBAYASHI ; Satoko SUDO ; Mahito TAKEDA ; Masanori KANEUCHI ; Noriaki SAKURAGI
Journal of Gynecologic Oncology 2011;22(1):3-8
OBJECTIVE: Few studies on the prognosticators of the patients with recurrent endometrial cancer after relapse have been reported in the literature. The aim of this study was to determine the prognosticators after relapse in patients with recurrent endometrial cancer who underwent primary complete cytoreductive surgery and adjuvant chemotherapy. METHODS: Thirty-five patients with recurrent endometrial cancer were included in this retrospective analysis. The prognostic significance of several clinicopathological factors including histologic type, risk for recurrence, time to relapse after primary surgery, number of relapse sites, site of relapse, treatment modality, and complete resection of recurrent tumors were evaluated. Survival analyses were performed by Kaplan-Meier curves and the log-rank test. Independent prognostic factors were determined by multivariate Cox regression analysis. RESULTS: Among the clinicopathological factors analyzed, histologic type (p=0.04), time to relapse after primary surgery (p=0.03), and the number of relapse sites (p=0.03) were significantly related to survival after relapse. Multivariate analysis revealed that time to relapse after primary surgery (hazard ratio, 6.8; p=0.004) and the number of relapse sites (hazard ratio, 11.1; p=0.002) were independent prognostic factors for survival after relapse. Survival after relapse could be stratified into three groups by the combination of two independent prognostic factors. CONCLUSION: We conclude that time to relapse after primary surgery, and the number of relapse sites were independent prognostic factors for survival after relapse in patients with recurrent endometrial cancer.
Endometrial Neoplasms
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Female
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Humans
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Multivariate Analysis
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Recurrence
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Retrospective Studies
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Survival Analysis*
6.Multivariate prognostic analysis of adenocarcinoma of the uterine cervix treated with radical hysterectomy and systematic lymphadenectomy.
Tatsuya KATO ; Hidemichi WATARI ; Mahito TAKEDA ; Masayoshi HOSAKA ; Takashi MITAMURA ; Noriko KOBAYASHI ; Satoko SUDO ; Masanori KANEUCHI ; Masataka KUDO ; Noriaki SAKURAGI
Journal of Gynecologic Oncology 2013;24(3):222-228
OBJECTIVE: The aim of this study was to investigate the prognostic factors and treatment outcome of patients with adenocarcinoma of the uterine cervix who underwent radical hysterectomy with systematic lymphadenectomy. METHODS: A total of 130 patients with stage IB to IIB cervical adenocarcinoma treated with hysterectomy and systematic lymphadenectomy from 1982 to 2005 were retrospectively analyzed. Clinicopathological data including age, stage, tumor size, the number of positive node sites, lymphovascular space invasion, parametrial invasion, deep stromal invasion (>2/3 thickness), corpus invasion, vaginal infiltration, and ovarian metastasis, adjuvant therapy, and survival were collected and Cox regression analysis was used to determine independent prognostic factors. RESULTS: An estimated five-year survival rate of stage IB1 was 96.6%, 75.0% in stage IB2, 100% in stage IIA, and 52.8% in stage IIB. Prognosis of patients with one positive-node site is similar to that of those with negative-node. Prognosis of patients with multiple positive-node sites was significantly poorer than that of negative and one positive-node site. Multivariate analysis revealed that lymph node metastasis, lymphovascular space invasion, and parametrial invasion were independent prognostic factors for cervical adenocarcinoma. Survival of patients with cervical adenocarcinoma was stratified into three groups by the combination of three independent prognostic factors. CONCLUSION: Lymph node metastasis, lymphovascular space invasion, and parametrial invasion were shown to be independent prognostic factors for cervical adenocarcinoma treated with hysterectomy and systematic lymphadenectomy.
Adenocarcinoma
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Cervix Uteri
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Female
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Humans
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Hysterectomy
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Lymph Node Excision
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Lymph Nodes
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Multivariate Analysis
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Neoplasm Metastasis
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Prognosis
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Retrospective Studies
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Survival Rate
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Treatment Outcome
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Uterine Cervical Neoplasms
7.99mTc-HSA-DTPA Scintigraphy of Protein-Losing Gastroenteropathy Associated with Mixed Connective Tissue Disease Before and After Immunosuppressive Therapy
Katsuya MITAMURA ; Takashi NORIKANE ; Yuka YAMAMOTO ; Kengo FUJIMOTO ; Yasukage TAKAMI ; Mikiya KATO ; Tomohiro KAMEDA ; Hiroaki DOBASHI ; Yoshihiro NISHIYAMA
Nuclear Medicine and Molecular Imaging 2021;55(1):46-47
We present a female in her sixties with mixed connective tissue disease who underwent 99mTc-human serum albumin diethylenetriaminepentaacetic acid ( 99mTc-HSA-DTPA) scintigraphy to clarify the cause of generalized edema. Scintigraphy findings directed the diagnosis to protein-losing gastroenteropathy. Various disorders are known to be associated with proteinlosing gastroenteropathy; however, mixed connective tissue disease is a rare cause. 99mTc-HSA-DTPA scintigraphy is helpful in the diagnosis and following the response to therapy of protein-losing gastroenteropathy.