1.Development of a simple and convenient feeding device to infect Aedes aegypti mosquitoes with Brugia pahangi microfilariae derived from the peritoneal cavity of Mongolian jirds
Yoshinori Mitsui ; Mitsumasa Miura
Tropical Medicine and Health 2010;38(3):97-101
It has become difficult in recent years to conduct the direct feeding of mosquitoes on animals because of ethical considerations related to animal experimentation. Thus, the artificial feeding of mosquitoes on blood meals is an important technique in studies on the oral infection of mosquitoes to agents. Since Rutledge et al. (1964) devised the artificial membrane-feeding technique, several artificial membrane-feeding methods have been developed to increase the feeding rates of mosquitoes on blood meals. The purpose of the present study is to develop a simple and convenient device for the artificial feeding of mosquitoes. We designed a device using Kimwipe®, a coverglass, the lid of a plastic dish and a 50 ml Erlenmeyer flask. The efficacy was assessed by the infection rate of mosquitoes to Brugia pahangi microfilariae (MF) derived from the peritoneal cavity of Mongolian jirds. Immediately after the feeding of mosquitoes on MF by the new device, the MF infection rate of mosquitoes was 50 - 81%. On day 14 post-feeding, 51 - 94% of mosquitoes harbored third-stage infective larvae. The components needed to construct the device for artificial feeding of mosquitoes are generally available in laboratories. Furthermore, no elaborate modification of materials is necessary in making the feeding device. Therefore, this simple and convenient artificial feeding device promises to be applicable for experimental infection of mosquitoes not only with B. pahangi MF but also with other agents such as malaria and viruses.
2.A STUDY ON HEART RATE AND SWIMMING SPEED IN THE VARIOUS INTERVAL TRAININGS OF SWIMMING
Mitsumasa Miyashita ; Hideji Matsui ; Mochiyoshi Miura ; Tamotsu Hoshikawa ; Sadaji Kamei
Japanese Journal of Physical Fitness and Sports Medicine 1969;18(1):1-8
The purpose of this study is to conduct the examination of heart rate and speed variations with respect to the various interval trainings of swimming. One trained, one post-trained and one untrained swimmers were employed for this study. The experiment was conducted during the summer of 1968. The temperature of atomosphere varied from 30°C to 33°C and that of water from 27°C to 29°C.
The data of heart rate were obtained from the record of ECG. Two electrodes or ECG consisting of silver cups of 10mm in diameter were attached to the skin over sternum. In order to avoid mechanical and electrical disturbances, the electrodes were tightly fixed through the following procedures;
1) The electrodes were pasted on cleaned skin with ECG jelly.
2) The adhesive plaster was placed over the electrodes.
3) The adhesive plaster was coated with wax.
The wire of 20 meters was used to connect the electrodes and the recorder. On trial of interval training was consisted of two phases; 1) The active phaseTo swim 50 meters according to his swimming ability. 2) The rest phase.To take a 0, 5, 10, 20, 30, 45 or 60 seconds interval between each 50 meters swimming. Each trial of training was repeated ten times.
Results are as follows;
1) The longer the rest period is, the higher the swimming speed is.
2) All swimmers swim 50 meters at 60-80% of their maximum speed and the percent of the trained is higher than that of the untrained.
3) Maximum heart rates of the trained, the post-trained and the untrained during tenth swimming are 188, 180 and 173 respectively, which are the same in every trial.
4) Decreasing rates of heart rate during the rest period are 10 under in 5-10 seconds interval, 15-25 in 20-30 seconds interval and 20-50 in 45-60 seconds interval,
3.MAXIMUM OXYGEN INTAKE AND ITS RELATION TO BODY WEIGHT —JAPANESE ATHLETES—
MOCHIYOSHI MIURA ; HIDEJI MATSUI ; MITSUMASA MIYASHITA ; KANDO KOBAYASHI ; MICHIO KIKUCHI ; HIROSHI SODEYAMA
Japanese Journal of Physical Fitness and Sports Medicine 1972;21(3):143-148
The present study was intended to determine max. Vo2 and its relation to body weight of Japanese athletes. The subjects in this study were 151 male and female athletes who were Japanese excellent or good runners and swimmers.
Max. Vo22 was determined during the maximum running on the treadmill. Treadmill test was made with a constant slope of 8.6%. During the first 2 minutes, the treadmill was set in motion at a certain speed (180 or 200 m/min for male and 160 m/ min for female), and then the speed was increased by 10 m/min every succeeding minute until exhaustion. Expired air during running was collected in Douglas bag every 1 minute upto exhaustion. The sampling gas was analyzed by means of a Beckman oxygen and carbon dioxide analyzer.
The results obtained in this study were as follows ;
1) The regression equations were calculated between max. Vo2 and body weight in relation to sex and sports (Table 1) .
2) Max. Vo2 per body weight of the male swimmers ranges from 50 to 70 and that of the male runners is 70 ml/kg/min. For the female swimmers max. Vo2 is between 40 and 60 and the female runners approximately 60 ml/kg/min.
3) The regression equation was calculated between the mean speed of 5000 m running as performance (Y) and max. Vo2 per body weight as physical resources (X) for the runners.
Y=0. 0431X+2.50±0.232