Receptors involved in flare reaction induced by acupuncture and moxibustion / 全日本鍼灸学会雑誌

[Objective]Capsaicin induces flare reaction in the human skin, and repetitive capsaicin applications induce capsaicin desensitization. To investigate the receptors related to flare reaction by acupuncture and moxibustion, we measured pain thresholds and flare reaction in two areas. <BR>[Methods]Thirteen healthy volunteers with informed consent participated in this study. Capsaicin (0.1%) was applied repetitively (6 h/3days) to the forearm skin to desensitize the area. Then, mechanical and heat pain thresholds, flare reactions that induced by acupuncture and moxibustion were measured. <BR>[Results]In the desensitized area, the heat pain threshold was significantly increased but the mechanical pain threshold did not change. Moxibustion induced flare reaction and it was significantly diminished under capsaicin desensitization. On the other hand, acupuncture induced flare reaction and it disappeared completely under capsaicin desensitization. <BR>[Discussion and Conclusion]These results revealed that the flare reaction induced by acupuncture and moxibustion requires TRPV1 activation. For the moxibustion, flare reaction was significantly diminished under capsaicin desensitization but remained significant. Therefore we suggest that TRPV1 mainly mediates the flare reaction but other heat sensitive receptors might be involved in flare reaction. While the mechanical pain threshold was not changed under capsaicin desensitization, flare reaction induced by acupuncture disappeared completely. This suggests that flare reaction is not induced by the mechanical stimuli of acupuncture itself, but other factors such as inflammatory mediators released from damaged cell causing flare reaction by acupuncture.

Electrical Activities Detected from the Experimentally-induced Trigger Points in Human Subjects / 全日本鍼灸学会雑誌

Electrical activities detected from the experimentally-induced trigger points in human subjects.<BR>Objectives : To examine the pathogenic mechanisms of the trigger points, electrical activities were recorded from the experimentally-induced trigger points.<BR>Methods : Nine healthy volunteers who gave informed consent were used. The adjustable loads were set around the third finger and repetitive eccentric contraction was loaded on the extensor digital muscles. The subjects were asked to keep the position as long as possible. The loadings (about 10s) were continued until his all-out effort and were repeated 3 times with 5 min resting periods. The electrical activities in the skin, fascia and muscle of the trigger point and non-tender region of palpable band and 10mm outside the band were recorded on the second day after the eccentric exercise.<BR>Results : Repetitive eccentric exercise produced a trigger point within the palpable band, which developed on the second day after the exercise. Electrical activities were detected only when the electrode tip was located in or near the fascia of the trigger point and there were subjective dull pain sensations. When the radial nerve was blocked by lidocaine, the needle EMG activity could not be recorded.<BR>Conclusions : These results suggest that the EMG activities are the result of nociceptive reflex, and the sensitized nociceptors in the fascia of the palpable band might be a substrate for the trigger point.

Examination of an Eccentric Contraction-induced Trigger Point Model Using Human Subjects / 全日本鍼灸学会雑誌

The nature of an experimental trigger point model produced by eccentric exercise was examined in seven healthy volunteers who gave their informed consent. Adjustable loads were set around the third finger and the subjects were asked to keep the position as long as possible. The loadings (about 10s) were continued until his all-out effort and were carried out 3 times interspersed with 5 min rest periods. Pressure pain thresholds (PPT) and deep pain thresholds (DPT) before exercise, and on the 2nd and 7th day after the exercise, were measured in the skin, fascia and muscles. On the 2nd day after the exercise, the PPT of the restricted area of the taut band was the minimum. A similar reduction of the DPT was observed only in the fascia of the restricted area. These results suggest that the present experimental model is useful for the further investigation of trigger points.

Identification of Trichophyton tonsurans by Random Amplified Polymorphic DNA

BACKGROUND: T. tonsurans is an anthropophilic dermatophyte mostly causing tinea capitis and tinea corporis. In East Asian countries, it has rarely been isolated until now. However, it is necessary for researchers in Asian countries to be more accustomed to T. tonsurans than before because of frequent international sports exchanges nowadays. OBJECTIVES: This study was performed to identify T. tonsurans by random amplified polymorphic DNA (RAPD) analysis. METHODS: Fifteen strains which were tentatively identified as T. tonsurans in Brazil were identified again by several conventional mycological tests and RAPD analysis. RESULTS: Among 15 Brazilian strains, 3 were identified as T. tonsurans, 8 T. mentagrophytes, 3 T. nJmwn and 1 T. raubitschekii by conventional mycological tests. This result was examined again by RAPD analysis. CONCLUSION: RAPD analysis is considered a rapid and reliable method for identification of T. tonsurans if the procedure is carefully standardized with adequate-primers.

Effects of Lumbar Acupuncture Stimulation and Sciatic Nerve Electrical Stimulation on Blood Flow to the Sciatic Nerve Trunk / 全日本鍼灸学会雑誌

Effects of acupuncture stimulation on the lumbar area and those of electrical stimulation of the sciatic nerve on blood flow to the sciatic nerve were studied using laser Doppler flowmetry in anesthetized rats. Changes in the nerve blood flow induced by acupuncture stimulation were not similar. Half of the blood flow responses correlated with changes in arterial blood pressure. In the other half, responses did not always agree with changes in arterial blood pressure. Electrical stimulation was administered to the sciatic nerve contralateral or ipsilateral to the blood flow measurement site. Electrical stimulation of the ipsilateral side increased nerve blood flow without increasing arterial pressure. Administraton of atropine slightly diminished the response. Contralateral nerve stimulation, changes in nerve blood flow were not accompanied by arterial pressure changes. These results suggested that nerve blood flow may increase without increment of the arterial pressure in response to certain types of acupuncture stimulation.

Suppressive effects on human flexion reflex induced by different pressure intensities and stimulation sites / 全日本鍼灸学会雑誌

Different intensities of pressure were applied to various tender or non-tender points and the suppressive effects on the flexion reflex were examined in 21 healthy humans (18-26 years), who gave informed consent. The sural nerve was stimulated transcutaneously with trains of 5 pulses at intervals of 13 sec (1.05-1.10x T, T : threshold) and evoked EMGs were recorded from the biceps femoralis muscle. Tender points in the contralateral forearm were detected by careful palpation, and conditioning pressure stimulation was applied at variousintensities by a push-pull gauge for 78 sec. Pressure applied to tender points induced slightly greater suppression of evoked EMGs than that to non-tender points (C statistics : time series analysis), although the difference was not significant (group comparison). Pressure intensities of ten and 50 % of pain tolerance pressure seemed to be adequate for suppression of EMGs in both tender and non-tender points. These results suggest that suppression of flexion reflex by pressure application in humans may be mediated by tactile and pain-related afferent fibers and the importance of adequate stimulus intensity for the induction of analgesic effects.

Effects of thermal stimulation on the flexion reflex in human subjects / 全日本鍼灸学会雑誌

Effect of thermal stimulation on the flexion reflex as a pain index was examined in healthy human subjects who gave informed consent (n=9, male, mean age 26 ± 8 years old). The evoked electromyogram (EMG) of biceps femoral muscle elicited by transcutaneous electrical stimulation of the sural nerve (5 trains of pulses at 100 Hz delivered at intervals of 13 sec) was successively recorded. The subjective pain sensation elicited by nerve stimulation was simultaneously recorded by the visual analogue scale (VAS) method. Significant correlation coefficients between the amplitudes of evoked EMGs and the stimulus intensity (r=0.791, P< 0.01), and the VAS value (r=0.724, P < 0.01) were observed. Conditioning hot water immersion of the hand (47 °C, 156s) tended to reduce the amplitudes of evoked EMGs, although change was not significant (P=0.678, Kruskal-Wallis test). However, C-statistics, a simple time series analysis method, demonstrated significant trends in several trials. These results suggest that the flexion reflex used in the present study is useful for pain research in human subjects and C-statistics are also useful for analyzing the effect on each individual.

Suppressive Effect of Thermal Stimulation on The Jaw-opening Reflex Evaluated by Single Subject Design. Application of C-statistic as a simple time series analysis / 全日本鍼灸学会雑誌

Suppressive effects of thermal stimulation of the tail on the jaw opening reflex were examined by the reversal design of single subject designs (SSD) in an urethane anesthetized rat. The results were evaluated by visual inspections of the graphs of moving averaged data and by C statistic as a simple time series analysis. The digastric evoked EMGs elicited by electrical stimulation of the gingiva (1.5x threshold intensity, 0.2Hz) had stable latency and biphasic wave form. Clear suppression of the JOR during thermal stimulation of 54°C for 30s was found by the visual inspection. The calculated C statistics based of 12 data of that of before and during thermal stimulation showed significant trends (p<0.05).<br>On the other hand, no significant trends were observed in baseline period and the data of 32°C thermal stimulation, and they were in agreement with the results of visual inspections.<br>These results indicate the noxious thermal stimulation activate the endogenous pain inhibitory mechanisms then induces analgesic effects, and the similar mechanisms were suggested to be participated in acupuncture or moxibustion stimulation-induced analgesia. Moreover the fact that evaluations by the C statistics agreed with the visual inspection suggests the validity of C statistic for evaluating the time series data in the SSD.