Biomedical subjects

Osamu Tokumaru

Publications and source records attributed to Osamu Tokumaru.

7 recordsLinked to original sources

PubMed2005

Effects of acupressure on gastric myoelectrical activity in healthy humans.

OBJECTIVE: Acupressure at Neiguan point (P6) has been used as an antiemetic in Eastern countries and many studies have reported its effectiveness on gastrointestinal symptoms. The aim of the present study was to investigate the effects of acupressure on gastric myoelectrical activity in healthy humans. MATERIAL AND METHODS: Fifteen healthy volunteers (9 M, 6 F) served as subjects. Acupressure at P6 was applied for 1 min followed by 1 min of rest, and this alternating sequence was continued for a total of 30 min. Electrogastrogram (EGG) was recorded for 30 min before ("baseline"), during ("acupressure") and after ("recovery") the application of acupressure. Heart rate variability (HRV) was also recorded to analyze autonomic nervous activities. RESULTS: The percentage of normal 3 cycles per minute slow wave (%NSW) was changed significantly by the application of acupressure (86.5+/-2.4, 92.3+/-1.2, 92.8+/-1.9% in the baseline, acupressure and recovery periods, respectively, p = 0.0424). The %NSW was significantly larger in the acupressure and the recovery periods than in the baseline period (p <0.03). The changes in %NSW from the baseline to the acupressure (r = -0.8598, p < 0.001) and to the recovery (r = -0.6422, p <0.01) periods were negatively correlated with the baseline %NSW. There was no change in HRV. CONCLUSIONS: Acupressure at P6 increased %NSW of gastric myoelectrical activity. The negative correlation between the baseline value and the change in %NSW may extrapolate a possible normalizing effect of acupressure on impaired gastric myoelectrical activity in symptomatic patients.

Acupressure↗

PubMed2005

Gamma knife surgery of the pituitary: new treatment for thalamic pain syndrome.

OBJECT: Although reports in the literature indicate that thalamic pain syndrome can be controlled with chemical hypophysectomy, this procedure is associated with transient diabetes insipidus. It was considered reasonable to attempt gamma knife surgery (GKS) to the pituitary gland to control thalamic pain. METHODS: Inclusion criteria in this study were poststroke thalamic pain, failure of all other treatments, intolerance to general anesthetic, and the main complaint of pain and not numbness. Seventeen patients met these criteria and were treated with GKS to the pituitary. The target was the pituitary gland together with the border between the pituitary stalk and the gland. The maximum dose was 140 to 180 Gy. All patients were followed for more than 3 months. CONCLUSIONS: An initial significant pain reduction was observed in 13 (76.5%) of 17 patients. Some patients experienced pain reduction within 48 hours of treatment. Persistent pain relief for more than 1 year was observed in five (38.5%) of 13 patients. Rapid recurrence of pain in fewer than 3 months was observed in four (30.8%) of 13 patients. The only complication was transient diabetes insipidus in one patient. It would seem that GKS of the pituitary might have a role to play in thalamic pain arising after a stroke.

Aged↗

PubMed2005

The effect of gamma knife irradiation on functions of striatum in rats.

OBJECT: An animal model has been developed to study the effect of gamma knife surgery(GKS) on cerebral function. METHODS: A rat was fixed in a newly developed Régis-Valliccioni frame that enables the target region to be planned directly on the magnetic resonance images. The left striatum was irradiated with 150 Gy via a 4-mm collimator of the Leksell gamma knife. Apomorphine (dopamine agonist) was administered to elicit a circling behavior (apomorphine test) after the GKS so as to examine the time course of the changes in dopaminergic functions of irradiated striatum. After a series of behavioral analyses, irradiated brains were subjected to histological examination. Necrosis was observed in the irradiated area surrounded by hemorrhage and gliosis. The distance between the histologically estimated and planned centers of the irradiation areas was 1.0 +/- 0.5 mm. The extent of the distance was due to errors along dorsoventral axis. The distribution of the irradiation areas influenced the activity and the circling behaviors in apomorphine test, which was suggestive of involvement of the nigrostriatal pathway. CONCLUSIONS: Targeting by using the Régis-Valliccioni frame was very accurate compared with targeting with coordinates based on brain maps used hitherto. Although targeting improved the accuracy, further effort will still be necessary to reduce errors along dorsoventral axis. The apomorphine test indicated a reduced dopaminergic function of the irradiated area including striatum, which accompanied histological changes after a high dose of irradiation (150 Gy).

Animals↗

PubMed2005

Patients with systemic sclerosis have unique and persistent alterations in gastric myoelectrical activity with acupressure to Neiguan point PC6.

OBJECTIVE: To assess the effect of acupressure on gastric myoelectrical activity (GMA) in patients with systemic sclerosis (SSc) and its possible influence on SSc-associated gastrointestinal (GI) dysmotility disorders. METHODS: Acupressure to Neiguan point PC6 (GI, antiemetic point) was applied while SSc patients and healthy control subjects were monitored by 4-channel surface electrogastrography (EGG) during 30-minute baseline, acupressure, and recovery intervals. Frequency of GI symptoms and modified Rodnan skin scores (mRSS) of SSc patients were recorded. Acupressure to PC10 (non-GI, sham) was also performed on SSc patients to assess the validity of PC6 as a modulator of GI gastric rhythms. RESULTS: In the SSc patients, PC6 acupressure resulted in significant, persistent percentage mean normal wave decreases with concomitant percentage mean bradygastria and tachygastria increases during the recovery interval. Increases in percentage mean coupling seen in controls were blunted in SSc patients. In SSc patients, PC6 acupressure resulted in significant percentage normal wave and percentage bradygastria changes in the recovery interval that were not obtained with PC10 acupressure. In SSc patients, mRSS were significantly correlated to baseline GMA percentage mean normal waves and bradygastria and frequency of abdominal bloating. The frequency of symptoms for heartburn were significantly correlated with changes in GMA (deltaGMA, baseline vs recovery). CONCLUSION: In SSc patients, PC6 acupressure revealed significant, persistent, and possibly unique alterations in GMA during the recovery interval. deltaGMA was significantly correlated with the frequency of heartburn symptoms. Further studies will assess if acupressure to PC6 can provide a therapeutic or prognostic utility with GMA or GI symptoms in SSc patients.

Acupressure↗

PubMed2003

EEG activity of aviators during imagery flight training.

OBJECTIVE: Imagery flight training (IFT) is widely used in aviation without neurophysiological evaluation. Electroencephalogram (EEG) during IFT was compared between experienced fighter pilots (FP) and novice pilots (NP). METHODS: Six FP and 9 NP performed imagery right bank, left bank, right roll, and left roll maneuvers. Each task was repeated 5 times in a random order. Instantaneous EEG power was calculated by the intertrial variance method. RESULTS: In FP, 3 waves of event-related desynchronization (ERD) were observed. The third ERD (ERD3) was observed at all the electrode positions except Fp1 which began 0.25 s before the beginning of IFT and reached its peak 0.25 s after the beginning of IFT. In NP, ERD was not related to the start of IFT. The difference in event-related EEG at the peak of ERD3 was not significant between FP and NP. However, the negative change to the peak of ERD3 was significantly larger in FP than in NP. CONCLUSIONS: It is speculated that ERD3 in FP may indicate the activation of cortical areas including visual- and motor-related areas involved in IFT. SIGNIFICANCE: It is speculated that the representation of IFT was programmed in visual- and motor-related cortical areas as an aviator's career advances.

Adult↗

PubMed2003

Vector analysis of electrogastrography during motion sickness.

Although the dominant frequency at 3 cpm of electrogastrography (EGG) is reported to shift to a higher frequency during motion sickness (MS), it is unclear whether the normal slow wave (NSW) disappears or not. The authors investigated changes in NSW using vector analysis of EGG. Fourteen subjects were exposed to a Coriolis stimulation to evoke MS. EGG was recorded from two sets of bipolar leads, placed perpendicular to each other representing x and y axes. Trajectories for each frequency were drawn on the x-y plane. The amplitude and phase difference at NSW were compared before, during, and after the stimulus for each subject. In those with a change in phase difference, changes in NSW and tachygastria were negatively correlated (P = -0.048), whereas in those without a change, they were not correlated. This indicated two different kinds of tachygastria due to MS: tachygastria with and without a change in NSW.

Adult↗

PubMedDate not supplied

Incidence of cancer among female flight attendants: a meta-analysis.

BACKGROUND: Airline flight personnel work in a unique environment with exposure to known or suspected carcinogens and mutagens including ionizing cosmic radiation. A meta-analysis was conducted to study whether the occupational exposure of female flight attendants (FA) increased their relative risk of cancer incidence. METHODS: A bibliographical computer search from 1966 to 2005 of cancer incidence cohort studies of female FA was performed. Combined relative risks (RRc) in cancer incidence were calculated by means of meta-analysis. RESULTS: RRc and 95% confidence interval (CI) for malignant melanoma and breast cancer in female FA were 2.13 (95% CI: 1.58-2.88) and 1.41 (1.22-1.62) (p < 0.0001). Excess risk was not significant for all-site cancer with RRc of 1.10 (0.99-1.21). CONCLUSIONS: The meta-analysis confirmed the significantly increased risks for malignant melanoma and breast cancer in female FA. Increased exposure to cosmic radiation during flight has been suggested as a potential occupational risk factor. Ultraviolet radiation exposure on board seems an unlikely occupational risk, but nonoccupational leisure time sun exposure is a possible risk factor. The etiology of the observed increase in incidence of some cancers remains controversial because assessment of possible confounders, especially nonoccupational exposure factors, has thus far been limited.

Air Pollutants, Radioactive↗