Quantitative Analysis of the Thermal Image of the Hand Dorsum in the Assessment of Peripheral Circulatory Impariment in Workers Exposed to Hand-Arm Vibration / 日本温泉気候物理医学会雑誌

Infrared thermography was performed on 38 forestry workers. The thermograms were analyzed separately for the left and right hands of each subject. Of 75 hands evaluated, vibration-induced white finger was noted in 18 (VWF group), and no symptoms were noted in 57 (non-VWF group). In addition to the above two groups, 42 subjects (84 hands) who had no symptoms of vibration exposure were used as a control group. Based of the thermograms taken after a local warming of the hands for 5min, the temperature distributions of the dorsal aspect of subject's hands were evaluated, and the thermal images of the hand with VWF were categorized into three main patterns. To establish a quantitative evaluation index that incorporates the characteristic thermal image observed in the VWF group, we constructed the representative parameters for each of the three thermogram patterns, and a linear discriminant analysis was performed using the presence or absence of VWF symptoms as the dependent variable and the constructed parameters as the independent variables. A discriminant score derived from this model expression was used as the evaluation index. The accuracy of the index was estimated according to a receiver operating characteristic (ROC) curve, and the area under the curve of 0.942 was obtained (p<0.001). When the cutoff point was set at the maximum point in the Youden index, the sensitivity of the VWF group was 94.4%, and the specificity of the non-VWF group and control group was 84.2% and 89.3%, respectively. These findings suggest that this newly proposed quantitative analysis method, which uses the thermal distributions of the dorsal side of the hand as indicators, may be useful for evaluating peripheral circulatory impairment of HAVS.

Development of new instrument for evaluating leg motions using acceleration sensors

The purpose of this study is to develop a new system for measuring leg motions using a portable three-dimensional accelerometer. The measuring system is composed of acceleration sensors (Micro Stone, MA3-10Ac), a data logger, a data reader, and a personal computer. The personal computer draws a graph of the acceleration of movements (i.e., accelerogram) from the output signals of the acceleration sensors. We then calculated the average acceleration to evaluate leg motions. We drew the accelerograms from 19 young subjects and 36 elderly subjects during the performance of physical fitness activities and walking. Different accelerograms were obtained from two subjects for different walking styles. The average accelerations at the lumbar, ankle and toe points were higher at all axes during movements from the physical fitness activities in the elderly subjects. The accelerations of leg motion at the knee point were, however, lower in the up and down axis in the elderly subjects than in the young subjects, although they were higher in the back and forth and the right and left axes. The new instrument has enabled us to evaluate leg motions by measuring three-dimensional acceleration during the performance of physical fitness activities and walking. The average accelerations of leg motions showed age-related changes. Thus, the average acceleration of leg motions may be used as a new index for evaluating leg motions at the dynamic state.

Development of New Instrument for Evaluating Leg Motions Using Acceleration Sensors

The purpose of this study is to develop a new system for measuring leg motions using a portable three-dimensional accelerometer. The measuring system is composed of acceleration sensors (MicroStone, MA3-10Ac), a data logger, a data reader, and a personal computer. The personal computer draws a graph of the acceleration of movements (i.e., accelerogram) from the output signals of the acceleration sensors. We then calculated the average acceleration to evaluate leg motions. We drew the accelerograms from 19 young subjects and 36 elderly subjects during the performance of physical fitness activities and walking. Different accelerograms were obtained from two subjects for different walking styles. The average accelerations at the lumbar, ankle and toe points were higher at all axes during movements from the physical fitness activities in the elderly subjects. The accelerations of leg motion at the knee point were, however, lower in the up and down axis in the elderly subjects than in the young subjects, although they were higher in the back and forth and the right and left axes. The new instrument has enabled us to evaluate leg motions by measuring three-dimensional acceleration during the performance of physical fitness activities and walking. The average accelerations of leg motions showed age-related changes. Thus, the average acceleration of leg motions may be used as a new index for evaluating leg motions at the dynamic state.

Serum Leptin Levels in Healthy Adolescents: Effects of Gender and Growth

Objectives: The purposes of this paper were to evaluate the serum leptin levels in healthy adolescents and to establish standard age variation curves. Methods: Nine hundred six (414 boys and 492 girls) healthy adolescents were investigated. The maximum increment age in height (MIA) was identified in 124 boys and 130 girls. The menarcheal age (MA) was obtained for 130 girls. Fasting leptin levels were measured by enzyme immunoassay. The MIA was calculated by proportional allotment of yearly height increments. Results: Serum leptin levels did not change in boys and girls from the ages of 9 to 11. They decreased after the age of 11 in boys, while they increased in girls. Stepwise multiple regression analysis revealed that serum leptin levels were closely related to pubertal stage. The levels decreased remarkably after MIA in boys and increased remarkably after MA in girls. We drew standard age variation curves of serum leptin levels by calculating the 25th, 50th and 75th percentiles for each age in both boys and girls. The percentile curves for boys were divided into pre-MIA and post-MIA curves. Those for girls were divided into pre-MA and post-MA curves. Conclusion: We have devised a potentially useful method for evaluating serum leptin levels in adolescents considering the effects of gender and growth.

Serum leptin levels in healthy adolescents: Effects of gender and growth

<p><b>OBJECTIVES</b>The purposes of this paper were to evaluate the serum leptin levels in healthy adolescents and to establish standard age variation curves.</p><p><b>METHODS</b>Nine hundred six (414 boys and 492 girls) healthy adolescents were investigated. The maximum increment age in height (MIA) was identified in 124 boys and 130 girls. The menarcheal age (MA) was obtained for 130 girls. Fasting leptin levels were measured by enzyme immunoassay. The MIA was calculated by proportional allotment of yearly height increments.</p><p><b>RESULTS</b>Serum leptin levels did not change in boys and girls from the ages of 9 to 11. They decreased after the age of 11 in boys, while they increased in girls. Stepwise multiple regression analysis revealed that serum leptin levels were closely related to pubertal stage. The levels decreased remarkably after MIA in boys and increased remarkably after MA in girls. We drew standard age variation curves of serum leptin levels by calculating the 25th, 50th and 75th percentiles for each age in both boys and girls. The percentile curves for boys were divided into pre-MIA and post-MIA curves. Those for girls were divided into pre-MA and post-MA curves.</p><p><b>CONCLUSION</b>We have devised a potentially useful method for evaluating serum leptin levels in adolescents considering the effects of gender and growth.</p>

Influence of Silver Spike Point Therapy on Autonomic Nervous Function Among Workers Exposed to Hand-Arm Vibration / 日本温泉気候物理医学会雑誌

To clarify the effects of Silver Spike Point (SSP) therapy on the autonomic nervous function, we evaluated changes in the peripheral circulatory function by second derivative photoplethysmogram (SDPTG) on 22 workers exposed to hand-arm vibration. We also examined the responses of the autonomic nervous function using the coefficient of variation of R-R interval (CV_R-R), total number of white blood cells (WBC), and the ratio of granulocyte (GC) and lymphocyte (LC) as indexes.<br>As a result, we observed improved peripheral circulation due to the SSP therapy, in which the average pulse rare (PR) tended to decrease, CV_R-R was not significantly changed by the therapy, and WBC and LC were significantly decreased by the therapy.<br>The 22 subjects were divided into two groups (low-value group, 8 subjects; high-value group, 14 subjects) according to the data of CV_R-R revised using Fujimoto's method. In the low-value group, PR tended to decrease, and SDPTG-index and c/a tended to increase. In the high-value group, on the other hand, CVR-R and LC tended to decrease and WBC significantly increased.<br>In conclusion, SSP therapy enhanced the parasympathetic nervous function and improved the peripheral circulatory function in the parasympathetic-nervous-function-impaired the group (low-value group). Furthermore, it suppressed the parasympathetic nervous function without affecting the peripheral circulatory function in the parasympathetic-nervous-function-enhanced group (high-value group).