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Volume 20 (1983)
- Issue 3 Pages 9-
- Issue 2 Pages 47-
- Issue 1 Pages 1-
Volume 20, Issue 1
Displaying 1-5 of 5 articles from this issue
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Shintaro YOKOYAMA, Hiroyuki OGINO1983 Volume 20 Issue 1 Pages 1-7
Published: April 15, 1983
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSRespiratory heat loss, Qres [kcal/h], is calculated according to thermodynamic theory,
Qres = Veie - Vaia [kcal/h] (1)
where V = air rate [kg dry air/h], i = enthalpy [kcal/kg dry air] and subscript e and a represent expired and inspired gas respectively.
ia = 0.240Ta + Xa (597.3 + 0.441Ta) [kcal/kg dry air] (3)
ie = (0.200Feo2 + 0.204FeCO2 + 0.249FeN2) Te+ Xe (597.3 + 0.441Te) [kcal/kg dry air] (4)
where F = ratio of each gas weight to total gas weight [-], T = temperature [°C] and X = humidity ratio [kg/kg dry air] .
Fanger (1970) presented a formula to estimate Qres consisted of the following equation.
Qrea = Ve [575 (Xe-Xa) + 0.240 (Te - Ta) ] [kcal/h] (5)
Using equation (6) for Ve with total metabolic rate, M [kcal/h], he proposed equation (7) .
Ve = 0.0060M [kg dry air/h] (6)
Qres = 0.0023M (44 - Pa) + 0.0014M (34 - Ta) [kcal/h] (7)
where Pa - the partial pressure of water vapour in inspired gas [mmHg] . We measured Ve, Feo2, FeCO2, FeN2 and M with 33 Japanese males during resting and daily working activities. We derived a new equation (8) for Ve with M.
Ve = 0.01020M - 0.15992 [kg dry air/h] (8)
In such activities equation (6) underestimated Ve [mean relative error (MRE) = 25.88%] . Using present 387 data we compared equation (1) with equation (5) . Each value from equation (5) was lower than that of equation (1) (MRE=5.45%) . It was concluded that under relatively low metabolic level equation (6) caused considerable errors. Equation (7) which is based on equation (6) can never estimate an accurate value of Qres. If equation (5) would be adopted to calculate Qres, the value of Ve should be predicted from equation (8) instead of equation (6) .View full abstractDownload PDF (682K) -
K. SHIRAKI, S. SAGAWA, N. KONDA, H. NAKAYAMA1983 Volume 20 Issue 1 Pages 8-15
Published: April 15, 1983
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSThe basic pattern of body water exchange was studied in four Japanese male divers during exposure to a thermoneutral 31 ATA (He-O2) environment for 3 days (Seadragon V) . The hyperbaric chamber temperature was raised from 25±0.5°C at 1 ATA (air) pre-dive to 31.5 f 0.3°C at 31 ATA. Both rectal and mean skin temperatures were measured every hour (including during sleep) and were maintained at the same level at both pressures. The exposure to 31 ATA induced an increase in the daily urine flow, and a corresponding reduction in the insensible (and evaporative) water loss without changing the total daily water output. However, the daily fluid intake decreased by 600 ml at 31 ATA, and hence the divers developed a state of negative fluid balance, as reflected by a reduction in body weight and an increase in hematocrit. All changes in the pattern of body water exchange observed at 31 ATA were gradually reversed during subsequent decompression. As observed in a previous dive to 31 ATA (Seadragon IV) in which there was a subtle cold stress (as indicated by the 1°C reduction in mean skin temperature at 31 ATA), the increase in daily urine flow at pressure was almost entirely due to the increase in overnight urine flow. However, the hyperbaric nocturia observed in the present dive was a water diuresis in nature what in the previous dive was an osmotic diuresis. These results indicate that the hyperbaric diuresis at 31 ATA is due to an increase in overnight urine flow, and that the hyperbaric nocturia is not in any way related to the subtle cold stress attendant to many hyperbaric environments.View full abstractDownload PDF (1868K) -
Shobu SATO, Takanobu AZUMA, Shinsuke TAKASHIMA, Takeshi YOSHIDA1983 Volume 20 Issue 1 Pages 16-22
Published: April 15, 1983
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSIn order to investigate the characteristics of the cold induced vasodilation (CIVD) in the workers using the vibratory tool, the finger skin temperature of 45 subjects exposed to vibration (group V) and 27 healthy subjects (group H) in thirties and fourties was measured by one hand immersion in water bath of 5°C for 10 minutes in winter.
Group V showed significantly lower mean value of skin temperature before cold exposure (BT) than that of group H. The frequency of the appearance of the CIVD in group V (53.3%) was lower than that of group H (88.9%) . In average, group V showed significantly lower mean skin temperature (MST), lower temperature of the first temperature rise (TFR) and smaller amplitude of temperature reaction (AT) than that of group H, whereas the time for the first temperature rise (TTR) was significantly longer in group V than in group H. The value of TFR and MST in the subjects in group V tended to be lower and the value of TTR in the subjects in the same group tended to be longer than the respective value in the subjects in group H, when they are compared at a given value of BT. The ratio of TFR to TTR, as well as that of MST to TTR, was smaller in group V than in group H. The difference in these relations between group V and H could be used to differentiate the characteristics of the CIVD in those groups.View full abstractDownload PDF (1031K) -
Eikazu SAKAGUCHI1983 Volume 20 Issue 1 Pages 23-35
Published: April 15, 1983
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSTo investigate the changes of body fluid balance during the course of adaptation and acclimatization to high altitude, rats and rabbits were exposed to a simulated altitude of 5, 500 m for 14 days. The changes in total body weight, visceral weight, circulating blood and plasma volume, radio-sodium space, and water content and specific gravity of plasma were measured prior to, during and after the exposure. In addition, a restricted feeding experiment corresponding to reduced consumption of food and water at altitude was also performed at sea level environment.
These animals lost their weight at the early stage of the exposure. Main parts of weight changes were broadly muscular and dermal tissue portions. Radio-sodium space was decreased in parallel with body weight until the 4th day of exposure. Plasma volume was decreased in similar pattern to sodium space. Water contents of plasma was clearly decreased at exposure and maintained the low level thereafter during exposure period. On the contrary, plasma specific gravity rose. At the experiment of restricted feeding, plasma water content rose at the 1st day and returned to the initial level at the 3rd day of experiment.
From these results, it seems likely that body water, particularly extracellular water, might be reduced first at the early stage of exposure, followed by partially accompanied reduction of boody fat and another compartments.
Extracellular fluid retained somewhat dehydrated level durnig exposure period. This dehydration was thought to be attribuded to at least 2 causes. The one is apparently reduced intake of food and water and the other cause is not clear yet. However, the experimental evidence that the water content of red cell has gradually risen is of much interest in conjunction with the second factors.View full abstractDownload PDF (1598K) -
Hiroshi OSADA, Eikazu SAKAGUCHI, Teruko SAKAGUCHI, Yoichi KONDO, Ryohe ...1983 Volume 20 Issue 1 Pages 36-41
Published: April 15, 1983
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSThere are several reports in the literature of adaptive changes in tissue lactic dehydrogenase (LDH) in response to environmental alteration. Serum LDH has also been reported to be elevated by hypoxia, however, mechanismus and implications of the enzyme elevation are not well defined. In this experiment, effects of chronic hypoxia on serum LDH and isoenzyme pattern in monkeys were examined.
Japanese monkeys weighing 7.5-12.0 kg were exposed to a simulated altitude of 18, 000 f t for 30 days in an air ventilated hypobaric chamber at 24 ±1°C. Ascent from sea level to altitude was accomplished at a rate of approximately 3, 000 ft/min. Blood samples were taken from cepharic vein under light anesthesia with ketamine hydrochloride (20 mg/kg) . The blood was allowed to clot, and the serum removed immediately. Serum LDH activity was determined according to the method of Wrbblewski, and LDH isoenzymes were separated by electrophoresis using the cellulose acetate membrane (TAITAN III) . Quantitative measurements of each isoenzyme were made by densitometric scanning of the stained isozymes.
Total LDH activity was increased gradually, and reached its maximum at 14th day of hypoxic exposure, which remained elevated for the rest of exposure period. The maximum enzyme activity was three times higher than the original pre-exposure level. After the decent from altitude to sea level, the enzyme activity was gradually recovered to the original level in 7 days. The percentages of LDH-1 and -2 in the total LDH sample were decreased after two weeks of hypoxic exposure. On the contrary, those of LDH-3, -4 and -5 were increased. LDH isoenzyme pattern shifted to anaerobic form in 2 weeks exposure, which probably corresponded to the period of altitude acclimatization, since monkeys recovered their appetite and physical activities at 14th day of hypoxic exposure.
From these results, it was suggested that changes in LDH activity and isoenzyme pattern might reflect the degree of adaptive changes in chronic hypoxia.View full abstractDownload PDF (878K)
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