Basically, adverse event report after vaccination is collected by free descriptive comments and sometime it is difficult to evaluate the reliability of diagnosis. Based on these actual situations, in abroad, standardized criteria was implemented for the collection and/or evaluation of spontaneous reports. In this article, we discussed regarding the measures to implement Brighton criteria, which is expanded as global standardized criteria, in Japan.

[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.
[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.
[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.
[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.

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).
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.
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.

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.

Electrical activities detected from the experimentally-induced trigger points in human subjects.
Objectives : To examine the pathogenic mechanisms of the trigger points, electrical activities were recorded from the experimentally-induced trigger points.
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.
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.
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.

The purpose of this study was to noninvasively extract information about the size and muscle fiber density of muscular units through the inverse analysis of surface electromyograms. Surface motor unit action potentials (MUAPs) were recorded with a multi-channel electrode array arranged along the circumference direction of the biceps brachii. The depth and intensity of equivalent current dipoles were estimated through the inverse analysis of surface MUAPs. The simulation of inverse analysis of surface potentials generated by the muscular unit models showed that the relationship between the depth and the intensity depends on the muscular unit size and muscle fiber density.
In the simulation, we systematically varied the model parameters including distance from the skin, radius, and fiber density and used the inverse analysis to estimate the depth and intensity of current dipoles. And, our method to estimate the radius and fiber density of muscular units using estimated depth and intensity is demonstrated. Mean values (± SD) estimated from the surface MUAPs were 3.0±1.8mm for depth and 13.8±32.0nAm for intensity. The estimated distance ranged from slightly less than 1 mm to slightly more than 2 mm. The estimated radius ranged from 1.8 to 4.6 mm and fiber density from 0.7 to 5.4 fibers/mm².

We have developed a method for estimating the depth and intensity of muscular unit represented as equivalent current dipoles by the inverse analysis of surface electromyograms (EMGs) . In this study, the validity of the locations of current dipoles estimated through the inverse analysis was verified by animal experiments. Surface motor unit action potentials (MUAPs) were recorded from the gastrocnemius muscle activated by electrical stimulation at the ventral root of lumbar spinal cord (L4 or L5) of rats. After recording the surface MUAPs for the inverse analysis and glycogen depletion of active muscle fibers by repeated electrical stimulation, periodic acid-Schiff (PAS) staining was used to determine the position of muscle fibers belonging to an active single motor unit. In the results of the inverse analysis, the values of ‘goodness of fit’ between measured and calculated MUAP were 71%, 79% and 85%. Estimated depths of current dipoles ranged from 1.8 mm to 5.9 mm. The locations estimated through the inverse analysis were more medial and shallower than the actual distribution of active muscle fibers determined by PAS staining. These errors were probably caused by the effects of the boundary in the model, the relationship between the measurement area and the location of an active motor unit, and the artifacts such as deformation of the muscle during dissection and freezing.