Health-Related Quality of Life in Active Persons with Spinal Cord Injury / 体力科学

This study aims at identifying how sports activity status, level of residual function, and independence in activities of daily living (ADL) affect the health-related quality of life (HRQOL) of persons with spinal cord injury (PSCI) who regularly participate in sports activities. Eighty-one male PSCI (21 persons with tetraplegia and 60 persons with paraplegia) who regularly participated in sports activities (wheelchair basketball or wheelchair twin basketball) were included in the present study. They were evaluated in terms of their characteristics, sports activity status, independence in ADL (Spinal Cord Independence Measure [SCIM]), and HRQOL (Medical Outcomes Study Short Form-36 [SF-36]). The age was a significant explanatory variable for physical functioning, role physical, and physical component summary (P < 0.05). On the other hand, the level of residual function was a significant explanatory variable for general health, vitality, mental health, and mental component summary (P < 0.05). The physical aspects of HRQOL of PSCI who regularly participate in sports activities were mainly affected by age, whereas the mental aspects were affected by the level of residual function.

A BATTERY OF FIELD TESTS FOR PREDICTING THE GENERAL PHYSICAL FITNESS LEVEL OF MALE PARAPLEGICS IN ACTIVE DAILY LIFE / 体力科学

<b>Purpose:</b> To investigate the factorial structure of physical fitness of male paraplegics with thoracic or lumbar spinal cord injury and to develop a battery of field tests for predicting their general physical fitness level.<b>Methods:</b> Fifty-three active male paraplegics with spinal cord injury (PSCI) (age range: 18-54; spinal cord injury level: T4 to L4) were examined. Thirteen feasible variables were selected using physical fitness components based on the International Committee for the Standardization of Physical Fitness Tests and previous PSCI studies. Factor analysis was applied to 14 variables; 13 of these involved physical fitness tests stratified by age to determine the factorial structure of physical fitness variables. Multiple regression analysis was performed to obtain a linear regression equation using a representative variable for each factor in the factorial structure as an independent variable. A first principal component score was obtained by principal component analysis using each variable as a dependent variable.<b>Results:</b> For factorial structure, wheelchair driving ability (3-minute shuttle run), body composition (sebum thickness), respiratory function (vital capacity) and shoulder joint extension force factors were obtained. The results of multiple regression analysis involved 5 variables (the 4 above-mentioned variables plus age); and the first principal component score of each subject from all variables provided a significant linear regression equation (r = 0.934, <i>P</i> ＜0.01) when the body composition factor was excluded.<b>Conclusions:</b> The representative measurement variables obtained from the factorial structure allowed for the development of a battery of field tests for predicting general physical fitness level of PSCI.

THE GENDER DIFFERENCES IN THERMOREGULATORY RESPONSES DURING EXERCISE RECOVERY / 体力科学

The purpose of this study was to investigate the gender differences in thermoregulatory responses during the recovery from prolonged exercise. Fourteen (7 males and 7 females) subjects cycled for 45 minutes at 55%VO₂max and then rested for 105 minutes in the hot and humid environment (30℃, 80% relative humidity) or cool environment (20℃, 60% relative humidity). Both males and females showed same variations in rectal temperature (Tre) during exercise and recovery periods. Total sweat volume and water intake were significantly larger in males than in females during recovery in the both environments. In the heat condition, mean skin temperature (Tsk) decreased immediately after the cessation of exercise in females but not in males (the recovery period (R) 5–15 min : <i>p</i><0.01, R15–20 min : <i>p</i><0.05). These results suggested there are gender-related differences in the mechanisms and also the process maintaining the balance of heat production and heat loss response during recovery from prolonged exercise. Moreover the heat might modify gender differences of heat loss response during recovery as an important factor.

Suppressive effect of culture supernatant of erythrocytes and serum from dogs infected with Babesia gibsoni on the morphological maturation of canine reticulocytes in vitro

The present study evaluated the effects of infected culture supernatant of erythrocytes, fractionation of culture supernatant and serum from dogs infected with Babesia gibsoni (B. gibsoni) on the maturation of canine reticulocytes in vitro. The SDS-PAGE demonstrated that significantly broader bands were generated by both the infected culture supernatant of erythrocytes and the serum from dogs chronically infected with B. gibsoni. The culture supernatant of erythrocytes infected with B. gibsoni strongly suppressed the maturation of reticulocytes. Prior studies showed that chronically infected serum had inhibitory effects on both the maturation of reticulocytes and the canine pyrimidine 5'-nucleotidase subclass I and purine-specific 5'-nucleotidase activity. In addition, serum free infected culture supernatant of erythrocytes had an inhibitory effect on the morphological maturation of reticulocytes. These results suggest that infected serum and culture supernatant of erythrocytes might accumulate excess proteins and/or metabolites as a result of the inhibited maturation of reticulocytes and decreased activity of erythrocyte 5'-nucleotidase. Furthermore, the fractions observed at >150 kDa- and 150-70 kDa- in the infected culture supernatant and serum retarded the maturation of canine reticulocytes in vitro. The results obtained from the in vitro examinations, in the present study, suggested that B. gibsoni itself and/or its metabolites might release certain proteins in the infected culture supernatant and serum from infected dogs and as a result delay morphological maturation of canine reticulocytes.

Effects of Water Ingestion Interval on Thermoregulatory Responses During Exercise in a Hot, Humid Environment / 体力科学

During exercise at high temperatures, body temperature increases impairing exercise performance and resulting in heat illnesses. Water ingestion during exercise is a simple and practical strategy to prevent hyperthermia. In the present study, we examined the effects of water ingestion interval on thermoregulatory responses during exercise in a hot, humid environment (32t, 80% relative humidity) . Eight male university students performed a 60-min cycling exercise (60% of the maximal O<SUB>2</SUB> uptake) under four separate conditions; no drinking (ND), water ingestion (mineral water) at 5 (D5), 15 (D15), and 30 (D30) min intervals. The total volume of water ingestion (TWI) was identical during D5, D15, and D30, and equal to the amount of fluid lost in sweat during ND. TWI was divided equally by the number of drinking times in each experiment. During exercise, both rectal and mean skin temperature were lower in D5 than those in the other conditions (p<0.05) . There was no significant difference in total sweat loss between the four conditions, however, evaporative sweat loss and sweat efficiency (evaporative sweat loss total sweat loss) were significantly (p<0.05) higher in D5 than those in the other conditions. These results suggest that the shorter water ingestion interval increases evaporative sweating and attenuates higher body temperature during exercise in a hot, humid environment.

Tympanic temperature and skin temperatures during upper limb exercise in patients with spinal cord injury / 体力科学

To clarify changes in body temperature during endurance exercise in patients with spinal cord injury (SCI), we measured tympanic temperature (Tty) and skin temperature in the head, arm, chest, thigh, shin and calf in 5 patients with SCI (T6-T 12) and 7 normal controls during 30 minutes arm cranking exercise (20 watts) from 10 minutes before the initiation of exercise until 10 minutes after the termination of exercise in an artificial climate room at a temperature of about 25°C with a relative humidity of about 50%. The Tty in the SCI group was lower than that in the control group from 10 minutes before the initiation of exercise to 10 minutes after the termination of exercise with a significant difference only at the initiation of exercise. The difference in Tty slightly decreased with continuation of exercise. The Tty in the SCI group at rest was 36.05-37.15°C. Four patients in this group showed a decrease of 0.04-0.12°C in the early stage and an increase of 0.66°C±0.19 (mean±SD) at the end of exercise over the value at the initiation of exercise.<BR>The skin temperature was lower in the SCI group than in the control group in all sites excluding the arm. Significant differences were observed in the head in the early stage of exercise and after exercise, in the chest from 10 minutes before the initiation of exercise to 5 minutes after the termination of exercise, in the thigh from 10 minutes before the initiation of exercise to 10 minutes after the termination of exercise, in the shin 10 minutes and 5 minutes before the initiation of exercise, and in the calf from before to 15 minutes after the initiation of exercise. In the SCI group, marked individual differences were observed in the skin temperatures in the thigh, shin, and calf, suggesting specificity of the skin temperature response in and near the paralysis area.<BR>Results in Tty in this study suggested no heat retention in the SCI patients. Therefore, the risk for heat disorders seems to be low during moderate or mild exercise under moderate temperature environment at a temperature of about 25°C with a relative humidity of about 50% even when the skin temperature is low, and thermolysis is not marked.

Are there benefits of sports participation in the prevention of pressure sores in spinal cord injured persons? / 体力科学

The purpose of this study was to investigate the benefits of sports participation in the prevention of pressure sores. A questionnaire was mailed to 668 men and woman with spinal cord injury. The questionnaire was designed to clarify the effects of physical activity and lifestyle on the development of pressure sores. Usable questionnaires were received from 466 persons, representing a response rate of 70%. Thirty-eight percent were quadriplegic and 62% paraplegic, with incomplete injuries accounting for 26% of the combined group. About half of the 466 subjects reported the development of pressure sores in their wheelchair life. Only 34% of the active subjects, participated in sports regularly, reported the development of pressure sores in their wheelchair life. On the other hand, 49% of the inactive subjects who did not participate in wheelchair sports reported the development of pressure sores. When the development of pressure sores before sports participation was compared with that after commencement of sports participation, there was no significant difference in the development of pressure sores between these periods. It was concluded that although quadriplegics and paraplegics without pressure sores had a greater tendency to participate in sports activity, there were no clear positive benefits of sports involvement on the prevention of pressure sores.

THERMOREGULATORY RESPONSES OF THE INITIAL STAGE OF BICYCLING IN A HEAT ENVIRONMENT / 体力科学

The purpose of this study is to determine the progress of whole body sweating rate (SR) in the initial stage of moderate work in two hot environments, and to relate the SR to the body temperature attained.<BR>Four healthy males, 28 to 31 years of age, performed leg exercise of 40% VO<SUB>2</SUB>max with a Monark bicycle ergometer set up on a platform scale (Potter bed balance) . All the experiments were carried out in a climatic chamber at ambient temperature (<I>T</I>a) of 30°C or 40°C (relative humidity, 45%) in winter season following body heating for 30 min at a room temperature of 30°C. Skin sweating was monitored by the bed balance with automatic weight change indicator throughout the experimental period. Rectal (<I>T</I>re) and 7 skin temperatures were measured every minute by a thermistor and thermocouples, respectively. Oxygen consumption was determined before and during the work by the Douglas bag method. Heart rate was recorded by electrocardiography throughout the experiment.<BR>At <I>T</I>a 40°C, the SR increased as soon as the work started, whereas at <I>T</I>a 30°C it took a few minutes. The mean SR during the work at <I>T</I>a 40°C was significantly higher than that at <I>T</I>a 30°C. The level of mean skin temperature (<I>T</I>sk) was higher at <I>T</I>a 40°C (35°C) than <I>T</I>a 30°C (33°C), and <I>T</I>re was approximately 37.3°C at <I>T</I>a 30°C and 40°C. The changes in the <I>T</I>re and <I>T</I>sk were similar in two different conditions. The negative correlations were found between the SR and the <I>T</I>sk during the work. The regression line was significantly different at <I>T</I>a 30°C and 40°C. The <I>T</I>sk decreased in proportion to increase of the SR. Moreover, there was a good correlation between the SR and heart rate during the work in both environments. Heat production stood at the same level in two different thermal conditions.<BR>The present study suggests that the body core temperature in working men is maintained at least constant level, since the evaporation in the initial stage of the work is largely stimulated, and the reduction of skin temperature may be caused by other factors than the evaporation.