ABSTRACT
BACKGROUND@#Chemical intolerance (CI) is a chronic condition characterized by recurring and severe symptoms triggered by exposure to low levels of odorous or pungent substances. The etiology of CI has been a controversial subject for a long time. The aim of this review is to summarize findings on the neurological processing of sensory information during and after exposure to low levels of odorous or pungent substances in individuals with CI, focusing on the brain function and networks.@*METHODS@#Scientific studies on CI published between 2000 and 2019 in academic peer-reviewed journals were systematically searched using medical and scientific literature databases. Only peer-reviewed articles reporting original research from experimental human studies directly associated with CI, and involving related neurological responses or brain imaging after exposure to odorous or pungent substances (i.e., in chemical provocation tests), were considered.@*RESULTS@#Forty-seven studies were found to be eligible for a full-text review. Twenty-three studies met the selection criteria and were included in this review. Evidence indicated that differences between subjects with CI and healthy controls were observed by brain imaging during and after exposure to odorous or pungent substances. Differences in brain imaging were also observed between initial exposure and after exposure to these substances. Neurological processing of sensory information after exposure to extrinsic stimuli in the limbic system and related cortices were altered in subjects with CI. A previous documentable exposure event was likely to be involved in this alteration.@*CONCLUSIONS@#This review documents consistent evidence for the altered neurological processing of sensory information in individuals with CI. Further neurophysiological research exploring the processing of extrinsic stimuli and cognition of sensation through the limbic system and related cortices in CI, and the appearance of symptoms in individuals with CI, are required.
ABSTRACT
<p><b>OBJECTIVE</b>The relation between daily maximum temperature and mortality rate has a V-shaped pattern; the mortality rate is lowest at a certain temperature, that is, optimum temperature (OT), and the mortality rate increases when the temperature becomes higher or lower than OT. OT is associated with climate, but the relation between OT and long-term average temperature, which is a frequently used index of climate, had an outlier (Okinawa) even in Japan alone. Our objective is to determine the best climate index for OT estimation.</p><p><b>METHODS</b>We obtained death certificate data, meteorological data and population data for Japan from relevant government ministries. All the data obtained were from 1972 to 1995 except for Okinawa's mortality data (1973 to 1995). Using smoothing spline with the degree of freedom fixed to 6, we computed the OTs for 47 prefectures in Japan. These OTs were exhaustively compared with percentiles of daily maximum, average, and minimum temperatures, along with the long-term average temperature.</p><p><b>RESULTS</b>Among the candidates of the best climate index, 80 and 85 percentiles of daily maximum temperatures (Tmax80 and Tmax85) showed the highest correlation coefficient with OT (R>0.9, much higher than the R for the long-term average temperature, i.e., 0.63), and the regression models using Tmax80 and Tmax85 best regressed the OT, that is, the difference between the observed OT and the expected OT was smallest when Tmax80 or Tmax85 was used. Unlike previously used average of daily mean temperature, Tmax80 and Tmax85 made Okinawa a nonoutlier. This characteristic is desirable because Okinawa's being an outlier is due to its maritime climate and the capacity to accommodate a different type of climate may expand the applicability of OT estimation method to wider regions in the world. A direct comparison of OT with Tmax75 to Tmax90 revealed that the difference is smallest for the percentile between Tmax80 and Tmax85.</p><p><b>CONCLUSION</b>We considered that a daily maximum temperature between Tmax80 and Tmax85 is the best climate index for estimating OT in Japan.</p>
ABSTRACT
Objective: The relation between daily maximum temperature and mortality rate has a V-shaped pattern; the mortality rate is lowest at a certain temperature, that is, optimum temperature (OT), and the mortality rate increases when the temperature becomes higher or lower than OT. OT is associated with climate, but the relation between OT and long-term average temperature, which is a frequently used index of climate, had an outlier (Okinawa) even in Japan alone. Our objective is to determine the best climate index for OT estimation. Methods: We obtained death certificate data, meteorological data and population data for Japan from relevant government ministries. All the data obtained were from 1972 to 1995 except for Okinawa’s mortality data (1973 to 1995). Using smoothing spline with the degree of freedom fixed to 6, we computed the OTs for 47 prefectures in Japan. These OTs were exhaustively compared with percentiles of daily maximum, average, and minimum temperatures, along with the long-term average temperature. Results: Among the candidates of the best climate index, 80 and 85 percentiles of daily maximum temperatures (Tmax80 and Tmax85) showed the highest correlation coefficient with OT (R>0.9, much higher than the R for the long-term average temperature, i.e., 0.63), and the regression models using Tmax80 and Tmax85 best regressed the OT, that is, the difference between the observed OT and the expected OT was smallest when Tmax80 or Tmax85 was used. Unlike previously used average of daily mean temperature, Tmax80 and Tmax85 made Okinawa a nonoutlier. This characteristic is desirable because Okinawa’s being an outlier is due to its maritime climate and the capacity to accommodate a different type of climate may expand the applicability of OT estimation method to wider regions in the world. A direct comparison of OT with Tmax75 to Tmax90 revealed that the difference is smallest for the percentile between Tmax80 and Tmax85. Conclusion: We considered that a daily maximum temperature between Tmax80 and Tmax85 is the best climate index for estimating OT in Japan.
Subject(s)
Oxytocin , Temperature , Climate , JapanABSTRACT
Objectives : The present study investigates the effects of body iron stores upon indices of biosynthesis and destruction of red blood cells (RBC) induced by a single session of cycling exercise.<BR>Design : Eight sedentary female students were divided into groups depending on their body iron stores : normal (C group, n=5) and iron deficient (D group, n=3) . Blood samples were collected at five time points of before (pre), immediately after (0 hours), then 1, 3 and 6 hours after exercise (248±31 kcal, 70% V0<SUB>2</SUB> peak level) . Osmotic fragility and serum haptoglobin (hp) concentration served as of for degradation, and δ-aminolevulinate dehydratase (ALAD) activity, erythropoietin concentration and number of reticulocytes served as indices of RBC biosynthesis.<BR>Results : A single session of cycling exercise did not affect the level of RBC, hemoglobin, hematocrit, serum iron, ferritin, transferrin saturation, hp and osmotic fragility in either groups. The δ-ALAD activity increased at 3 (p<0.05) and 6 hours (p<0.01) after exercise compared with that at 0 hours in the C group. In contrast, δ -ALAD activity in the D group was significantly lower at 3 hours after exercise than that of C group (p<0.001) . Reticulocytes and erythropoietin concentration increased gradually in the C group after exercise, but not in the D group.<BR>Conclusions : A single session of cycling exercise under our experimental conditions enhanced RBC biosynthesis indicated by δ -ALAD activity, whereas exercise-induced hemolysis was not evident. Body iron stores affect the δ -ALAD activity induced by a single bout of cycling exercise.
ABSTRACT
Phagocytic cells, polymorphonuclear leucocytes and macrophages, play an important role in non-specific cellular immunity, which is the first line of defense against infectious diseases. The purposes of this study were to clarify the combined effects of forced exercise and sleep disturbance on non-specific cellular immunity in mature rats, and to compare the effects between forced and voluntary exercise. Non-specific cellular immunity represented by the yield of cells from bronchoalveolar lavage and the superoxide-generating capacity of alveolar macrophages was investigated using mature rats.<BR>Male Wistar rats (11 weeks old) were divided into 5 groups:<BR>1) Training group ; exercised on a treadmill at a belt speed of 35 m/min for 15 min/day, <BR>2) Jet Lag group ; disturbance of the sleep cycle by day/night time shifts at 2-week intervals, <BR>3) Training+ Jet Lag (T + J) group ; exercised on a treadmill with sleep disturbance, a model identified by our research group to simulate chronic fatigue, 4) Voluntary group ; housed with running wheels, and 5) Control group ; housed under sedentary conditions.<BR>Body weight and food consumption measured during the experimental period showed coincidental changes. After 6 weeks of the experiment, the rats were sacrificed at the age of 17 weeks. Negative effects on non-specific cellular immunity were observed in the training group, and the rats were also slightly affected by sleep disturbance (Jet Lag group) . These negative effects seemed to be cumulative in the T+J group. In contrast, significant positive effects were observed in the voluntary group.<BR>These results suggest that stress, forced exercise and sleep disturbance negatively affect non-specific cellular immunity, and that voluntary exercise is able to enhance immunity even if it is started after maturation.
ABSTRACT
The principal objective of this paper is basic research on the development of an easy and rapid method to estimate physical fatigue levels. The focus of the research is to determine chronically fatigued conditions at an early stage for the prevention of chronic fatigue. Special attention was given to overtraining as one form of chronic fatigue in this paper. Long-distance runners representatives of a university in Tokyo nominated for Hakone-Ekiden were recruited as subjects. Examinations with informed consent were carried out on a once a month basis during 8 months and included the following; 1) physical characteristics ; body weight and body fat weight, 2) serum-biochemical test ; 6 parameters by the dry-chemistry method and the traditional method, 3) subjective fatigue levels ; the questionnaire of subjective symptom authorized by the Japan association of industrial health and the profile of mood state (POMS) . In this paper, data obtained from 19 male runners attending all 8 examinations were statistically analyzed.<BR>Serum parameters obtained by the dry-chemistry method, an easy and rapid method which provides clinical values on site, showed significant correlations with the traditional method.<BR>No correlation was observed between subjective fatigue scores and serum enzyme activity levels which were used as markers for estimation of physical fatigue levels in this study, however, monthly changes of enzyme levels and fatigue scores from July to August seemed to correlate in almost subjects. In contrast, using data obtained in the entire exprimental period, there was no relationship between the monthly changes of enzyme levels and fatigue scores. The results may indicate that some subjects exhibit gaps between physical fatigue and feelings of fatigue.<BR>The above mentioned results suggest that measurements of serum enzyme activity levels using the dry-chemistry method are a useful indicator for the prevention of overtraining.
ABSTRACT
Phagocytic cells, polymorphonuclear leucocytes and macrophage, play an important role in a non-specific cellular immunity which is first defense line for infectious disease. The purpose of this paper is to clarify combined effects of stressful exercise and sleep disturbance on rat non-specific cellular immunity represented by yields of cells from bronchoalveolar lavage and superoxide generating capacity of alveolar macrophage.<BR>Male Wistar rats ( 5 weeks old) were divided into following 4 groups. 1) Training group; exercised on a treadmill at a belt speed of 35 m/min for 45 min/day, 2) Jet Lag group; noninvasive sleep disturbance by the shifted day/night time every 2 week interval, 3) Training + Jet Lag (T+ J) group ; exercised on a treadmill with sleep disturbance, that we assumed one of chronic fatigue model in this paper, and 4) Control group ; set sedentary condition.<BR>After 6 weeks of the experiment, 2 groups were newly selected from T + J group for the examination of rest effects on the chronic fatigue model rats. And to examine the combined effects of stressful exercise and sleep disturbance on matured rats (11 weeks old), Acute Training + Jet Lag (AT+J) group was selected from the Control group.<BR>Rats were sacrificed at 11 and 17 weeks old. T + J group seemed to be able to adapt first 6 weeks but negative effects were found out at 17 weeks old. Same phenomena were also recognized in AT + J group. These results suggest that the chronic fatigue model rats may easily catch the infectious disease and there are possibility that both stress, stressful exercise and sleep disturbance, negatively affects the non-specific cellular immunity, especially after maturation.