Recently, various laser Doppler flowmeter (LDF) systems have been used for evaluation of tissue microcirculation. However, indifference has often been shown by doctors and researchers regarding their sampling volume, stability and accuracy, which differ with various optical arrangements. In this study we evaluated the characteristics of three LDF systems with different optical arrangements. The sampling depths in both blood and tissue were found to differ with the different optical arrangements, although the laser power emitted from the probes is nearly equivalent. Each depth significantly changed at haematocrits between 5.0 and 36.5%. The stability and the accuracy of the measurements also differed. In the practical case of tissue microcirculation it is important to measure blood flow with an understanding of the material differences in the characteristics of the LDF systems.

Animals↗

PubMedDate not supplied

A needle type therapeutic system incorporating laser light and lumin for immunotherapy of cancer growing in deep organs.

Lumin is a potent cell-activating agent and a photosensitizer characterized by absorption peaks at 670 nm and 770 nm. It has already been demonstrated that macrophase activity is enhanced greatly by lumin administration with laser light irradiation and that this method is useful in cancer immunotherapy. In this study, a new needle type therapeutic system was developed for the immunotherapy of cancer growing in deep human organs. A human lung cancer grafted onto nude mice was strongly cicatrized by collagen fibres about four weeks after the first treatment. The collagen fibres seemed to seal-off the tumor and prevent its growth with intense cicatrization. In addition, a high T/B cell ratio of lymphocytes was observed in the peripheral blood of the treated mice, although the thymus is congenitally absent from nude mice. These results demonstrated that the system is a reliable method for cancer treatment in deep organs without side effects and/or major surgical intervention.

Adenocarcinoma↗

PubMedDate not supplied

Muscle fiber conduction velocity during isometric contraction and the recovery period.

Changes of muscle fiber conduction velocity (MFCV) detected by surface array electrodes during an isometric contraction and the recovery period were evaluated. The location on skin measured for action potentials of muscle fiber in m. biceps brachii was a distance of 5 mm and 30 mm from the end-plate to the distal tendon. The MFCV was evaluated by averaging raw EMG waves. The MFCVs at both locations declined gradually during the loads of sustained isometric contractions of 30, 50, and 70% of the maximum voluntary contraction (MVC). The degree of the decrease of the MFCV was extremely intense during a sustained contraction of 70% MVC. The values of the MFCV at the location of 5 mm from the end-plate in the period close to the exhaustion state showed a significant decrease compared with the values in the initial period during the contractions for the above three kinds of loads, while the decrease of the MFCV at the location of 30 mm from the end-plate was not found to be so significant during the contractions. In the recovery period, the contraction of 5% MVC was maintained, and the resultant MFCVs restored gradually to the value of the initial period. At the location of 5 mm from the end-plate, the MFCVs at 15 minutes after the end of the load were significantly higher than those just after the end of the load. At the location of 30 mm from the end-plate, the increases of the MFCVs during the recovery period did not show significant changes. Changes of the MFCV during the isometric contraction and the recovery period depend greatly on the location of the electrodes measured for the action potentials of the muscle fibers.

Adult↗

PubMedDate not supplied

Distribution of muscle fiber conduction velocity of m. masseter during voluntary isometric contraction.

Muscle fiber conduction velocity (MFCV) is the velocity of an interference wave due to muscle fiber action potentials. In general, it has been reported that the value of MFCV in m. masseter is larger than that in limb and trunk muscles. But the values of MFCV in the reports were measured in part of the muscle, and the distribution of MFCV in the whole muscle including the end-plate and the tendon has not been measured. In this study, surface myoelectric signals are recorded in m. masseter during voluntary isometric contractions of 20, 30, and 40% MVC (maximum voluntary contraction) in eleven healthy male subjects with the use of array electrodes. The value of MFCV is found directly using an averaging method. The end-plate zone is concentrated in the lower quarter of the muscle. The distribution of MFCV depends on the location of the measured electrode. The largest value of MFCV of more than 20.0 m/s is obtained in the locations of the end-plate and the tendon. The minimum value of MFCV is obtained at the location of 10 mm measured from the end-plate along the direction of the muscle fiber to the tendon of the upper side. The mean values with the standard deviations during 20, 30, and 40% MVC are 10.3 +/- 0.7, 11.6 +/- 0.7, and 12.2 +/- 0.8 m/s, respectively. The MFCVs between the different neighboring locations are compared and found to be significant by a level of 1% for each contraction level. The MFCVs increase depending on the contraction levels for various electrode locations on the muscle.

Adult↗

PubMedDate not supplied

Influence of hyperbaric environment on physiological tremor.

The effect of pressured environment from 1 to 24 ATA (Atmosphere Absolute) on total power spectrum (TP) of physiological tremor, whose value was the sum of power spectra for frequency range in 0.5-50 Hz, was investigated. The main effects obtained were as follows. (1) In the case of 3 ATA, TP during the pressure holding period denoted a similar value as the value in 1 ATA. In the latter half of the period, the TP increased. When the pressured environment is 4 ATA, in which the partial pressure of the nitrogen gas was 3.6 ATA, the TP decreased during the pressure holding period compared with the value in 1 ATA. Nitrogen narcosis was recognized at the partial pressure of 3.6 ATA, thus the effect denoted a decrease of TP. (2) In the cases of 16 and 19 ATA using heliox gas, during the pressure holding period, TP decreased compared with the value in 1 ATA, but in the case of 24 ATA the value increased. The partial pressure of helium gas of 23.6 ATA indicated a high pressure nervous syndrome, therefore, the influence of high pressure on TP was recognized as one of the causes of the increase of TP. (3) The influence of inhibitors of the autonomic nervous system on TP during the pressure holding period of 3 ATA was recognized. After intake of the inhibitor for the parasympathetic nerve (atropine) during the pressure period, TP increased, while for the intake of the inhibitor for the sympathetic nerve (propanol), TP decreased.

Atmospheric Pressure↗

PubMedDate not supplied

On the evaluation of muscle fiber conduction velocity considering waveform properties of an electromyogram in M. biceps brachii during voluntary isometric contraction.

The surface myoelectric signal during 20% maximum voluntary contraction was measured in m. biceps brachii using array electrodes for ten subjects in order to evaluate the distribution of muscle fiber conduction velocity (MFCV) in a whole muscle. MFCV was estimated by two calculating methods of the peak maximum method and the cross-correlation method from the myoelectric signals which were processed by techniques of the averaging and the non-averaging. It was found that the values of MFCV depended on the location irrespective of the kind of calculating method used and the kind of processing technique of myoelectric signal. In both the motor end-plate zone and the tendon zone, the values of MFCV showed more than 7.0 m/s. In the regions other than the motor end-plate zone and the tendon zone, the values of MFCV showed about 3.90 m/s which were almost constant. The statistical differences of the values of MFCV were in the same locations measured not recognized between the two calculating methods nor between the two processing techniques. In the cross-correlation method, the relation between MFCV and the electrode location was evaluated by both the maximum correlation coefficient and the amplitude ratio between the different neighboring channels to evaluate the conductive waveform properties of action potentials. The changes of parameters (i.e., MFCV, maximum correlation coefficient and amplitude ratio) depended on the electrode location. The values of MFCV significantly increased in the regions of the motor end-plate zone and the tendon zone, where the maximum correlation coefficient and amplitude ratio significantly decreased. The values of the coefficient of variance (CV) of three parameters in those regions were larger than those in other regions, i.e., the regions other than the motor end-plate zone and the tendon zone. A high maximum correlation coefficient and a high amplitude ratio were necessary for a reliable measurement of the MFCV.

Adult↗

PubMedDate not supplied

Influence of location of acceleration sensor on physiological tremor of upper limb.

The physiological tremor of the upper limb in three positions of pronation, neutrality, and supination due to the movement of forearm was measured on four locations at the tip of the finger, the root of the finger in the hand, the wrist, and the elbow with use of an accelerated sensor. The evaluation of the total power, which was the summation of the power spectrum in the frequency range from 1 to 50 Hz, showed no significant difference in any of the positions. The maintenance of the upper limb at the horizontal level showed the coordination of the central nervous system due to the body parts of the upper arm, forearm, hand, and finger connected by the joint. The coherence spectra showed clear activation of the joint of the wrist in the main peak frequency of around 2.5 and 12.5 Hz in their respective positions. The value of the correlation coefficient in the location between the hand and finger was the largest at over 0.8, and those of the locations which connected the joint of the wrist between the forearm and hand and between the forearm and finger were significantly large with a value from 0.6 to 0.8. The mean time (i.e., arrival time) of the transmission from the proximal side (i.e., upper arm and forearm) to the distal side (i.e., hand and finger) in the upper limb was evaluated quantitatively to be 20 ms for pronation and supination, but the value was small for neutrality.

Acceleration↗