The purpose of this study is to examine whether ambient temperature affects change in pulmonary diffusing capacity for carbon monoxide caused by hypoxia.Five male young adultswere exposed to the simulated altitude of 0, 2000, and 4000 m.Pulmonary diffusing capacityduring rest and exercise was tested in four different ambient temperatures of 16, 20, 24, and 28°C in each altitude.There was no temperature effect on diffusing capacity at sea level.However, at 2000 and 4000 m, diffusing capacity in a cool environment below 20°C wasincreased significantly compared with that in 28°C during rest and mild exercise(300kgm/min).Diffusing capacity during hypoxia was predicted, which was presumed that pulmonarycapmary blood volume was the same one at sea level.As aresult of comparison betweenmeasured and predicted value at high altitude, there were no differences on every occasions at 2000m, while significant increase in measured diffusing capacity was observed in a coolenvironment during rest and mild exercise at 4000m.It was implied that gas exchange surfacearea was increased during hypoxia in a cool environment caused by increase in capinary bloodvolume in itself and/or change in distribution of capinary blood flow in the lungs.However, these effects were relatively reduced at either ambient temperature above 24°C or work rateabove 300 kgm/min.It was concluded that a degree of hypoxic effects on pulmonary diffusingcapacity were related closely to ambient temperature and energy expenditure and that theseeffects became larger in a cool environment during rest at higher altitude.

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The experiment of 50 hours sleep deprivation for 4 males aged 21 to 22 years was performedfor a week including one adaptation day, two baseiine days, and two recovery days, the loadduring all the awakening times being mah-jong. Physioiogical parameters, performance, andquestionnairs were studied. During the sleep deprivation, the sequence of the occurrence of large change for the parameters was found to be the order of subjective fatigue feelings, theperformance (optical choice reaction time and critical flicker fusion frequency), and heart rateThe influence to the sleep showed that the slow wave sleep and REM sleep played theimportant role in the first and the second recoveryday, respectively.

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The relationship between increase in rectal temperature and body build during submaximalwork was studied in 8 Japanese males.After resting at 28°C with 50% relative humidity for30min, subjects worked on a bicycle ergometer at load of 450kgm/min with pedaling frequency50rpm for 61min at 28°C or 45°C with 50% relative humidity.Rectal temperature, oxygenuptake and heart rate were measured at rest and during work.Relative work loads wereobtained from prediction of maximal oxygen uptake.Body weight, stature, skinfold thicknessand body density were measured.Body surface area, body fat % and mean skinfold thicknesswere caiuculated by prediction equations.The correlation coefficients between increase in rectal temperature and body build at 45°Cwere larger than those at 28°C.In the conditicn of 45°C, body surface area-to-mass ratio wascorrelated significantly with increase in rectal temperature, whereas the relationship was notsignificant at 28°C.In the condition of 28°C, sigmificant relationship between relative work loadand increase in rectal temperature was found.Body suriace area-to-mass ratio, which meansrelative heat exchange between human body and environment, affects the change in rectaltemperature at high ambient temperature.

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The following five categories of measurements were treated for the evaluation of the abilityto sustain standing for one hour.The morphological items, e.g., stature and weight (A) and thephysical fitness, e.g., jumping height and strength of back (B) were measured before the standing.The other measurements obsemed during the standing posture were the physiologicalones like heart rate and respiration rate (C), the spontaneous movements of various body parts(D), and the subjcctive feeiings, e.g., boredom or pain (E). The data of thirty eight items in thefive categories for eighteen female subjects aged twenty one to twenty two years were used forthe principal component analysis.The first, the second, and the third principal componentswere fomd to be important factors related to the ability to maintain the standing posture.An index was defined to represent the prolonged and sustained standing ability syntheticallyby statistical treatment of both (1) the scores of each subject for the above three principalcomponents and (2) the proportions of these principal components.

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The purpose of this study is to investigate the effects of type and workload of exercise, ambient temperature and season on the prediction equation of maximal oxygen intake(VO₂max). Sixteen adult males were used as the subjects. The subjects were given submaximalworks by a bicycle ergometer exercise and a step exercise under the four kinds of environ-ment(warm in summer, cool in summer, warm in winter, cool in winter). Prediction equationsexamined in this study were those of Astrand and Rykming (1954), Margaria et al.(1965) andSato et at.(1976-b, 1980).As for the type and workload of exercise and ambient temperature, the accuracy of predictedVO₂max from the prediction equations of Astrand and Ryhming, Margaria et al.and Sato etal.(1976-b) was not sufficient compared with that from the prediction equation from Sato et al.(1980).In the prediction equation of Sato et al.(1980).however, seasonal difference in predictedVO₂max was fomd.

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The CO₂ rebreathing method for the determination of cardiac output has been computerized.CO₂ concentration of expired air is analyzed by a infrared CO₂ analyzer.The output voltageof the CO₂ analyzer is sampled by a micro computer through a 12-bit analog-to-digitalconverter.The values of end-tidal CO₂ percentages (FET_CO₂) during nomal respiration and thepeak values of CO₂ percentages in the lung-bag system (Fb_CO₂) during rebreathing are detectedby the computer automatically.The detemination of the partial pressure of CO₂ in mixed venous blood (Pv_CO₂) is perfomedby computer analysis.The rise in the partial pressure of CO₂ in the lung-bag system (Pb_CO₂)with time (T) is expressed by the equation [chemical formula] This equation can be transfomed logerithmically to [chemical formula] At first, Pvco₂ is assumed to be a slightly large value than the last value of Pb_CO₂ and theregression equation of ln (1-Pb_CO₂/Pv_CO₂) on T is calculated by means of the least-squaresanalysis.Then Pv_CO₂ is successively changed positively, and the regression equations arecalculated on each time.The value of Pv_CO₂ which maximize the value of coefficient ofdetermination (r²) is adopted as the very value of Pv_CO₂.The partial pressure of CO₂ in arterialblood (Pa_CO₂) is a ssumed to be the same as in end-tidal air.A comparison was made between the cardiac output determined by this computerized andthe conventional CO₂ rebreathing methods as described by Jernerus et al.(1963).The valuesobtained by the two methods were almost identical, all of 9 paired deteminations of cardiacoutput obtained during exercise were within 10% of one another and 33 of 36 values during restand recovery were within 20% of one another.The correlation coefficient between the valuesobtained by the two methods was 0.992.The computerized method is a more precise and moreconvenient technique for deteming cardiac output.

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There are many experimental studies to investigate sleep-wakefullness in man and othermammals.In the animal experiment cat, as well as rat, is a good experimental subject widlyused in this field of study, because there are little inter-individual neuroanatomical differences.In this report there presented a conventional technigue for successive polygraphical recordingof sleep-wakefunness in chronic cat, which is one of the most basic method to investigate thephenomenon of sleep-wakefullness and its mechanism.The general method is consisted of (a)preperation or thesurgical operation for implantation of pamanent electrodes and (b)recording and data analyzing system.

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Themechanism for generating microvibration(MV) or minor tremor has been proposed by manyinvestigators.Rohracher (1955) postulated thethermoregulatory autonomic nervous system.Sugano and Inanaga (1960) proposed the reflex ofspinal cord by γmotor system, and Ozaki et al.(1962) insisted the ballistocardiogram by heart beat.The contribution of the upper central nenroussystem (CNS) to MV was also reported (Sugano andInanaga, 1960:Itoh, 1967). We have considered thatthe CNS contributs much effect upon three factorsstated above.The unifom-interpretation of themechanism of MV, however, has not been given yet.The aim of this investigation is to give the relation-ship between eyelid MV and electmoencephalogram(EEG) in order to study the contribution of the CNS on MV.

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[in Japanese]

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