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Background Body composition (BC) influences respiratory system mechanics, provoking air flow limitation (AFL). The objective of this study was to determine the relationship of AFL in small- and medium-caliber airways with BC in young adults. Methods Eighty-three individuals were recruited (40 men and 43 women). To determine AFL, the following measurements were taken: forced expiratory volume in the first second (FEV1), forced expiratory flow between 25 and 75% (FEF25–75%), airway resistance (Raw), and specific airway resistance (sRaw). The measured BC variables were body mass index (BMI), body fat percentage (%BF), and fat-free mass (FFM). Binary logistical regression analysis was used to estimate the association between the AFL variables and %BF, BMI, and %FFM, adjusting for weight and gender. Results Among men, a relationship was observed between Raw and %BF (r = 0.728; p < 0.0001) and sRaw and BMI (r = 0.617; p < 0.0001). Among women, significant relationships were reported between Raw and BMI (r = 0.615; p < 0.0001) and sRaw and BMI (r = 0.556; p < 0.0001). Among participants with a BMI over 30 kg/m2, higher risks of increased Raw (OR = 26.8; p = 0.009) and sRaw (OR = 9.3; p = 0.002) were observed. Furthermore, higher %BF was associated with greater risks for increased Raw (OR = 14.04; p = 0.030) and sRaw (OR = 4.14; p = 0.028). In contrast, increased %FFM (OR = 0.14; p = 0.025) was a protective factor for lung function. Conclusion Increased %BF is associated with increased AFL in small-caliber airways. Furthermore, increased %FFM is associated with decreased risk for Raw and sRaw in women. Therefore, evidence indicates that increased %FFM is a protective factor for adequate lung function.

Malaria is one of the most devastating infectious diseases of humans. It is problematic clinically and economically as it prevails in poorer countries and regions, strongly hindering socioeconomic development. The causative agents of malaria are unicellular protozoan parasites belonging to the genus Plasmodium. These parasites infect not only humans but also other vertebrates, from reptiles and birds to mammals. To date, over 200 species of Plasmodium have been formally described, and each species infects a certain range of hosts. Plasmodium species that naturally infect humans and cause malaria in large areas of the world are limited to five-P. falciparum, P. vivax, P. malariae, P. ovale and P. knowlesi. The first four are specific for humans, while P. knowlesi is naturally maintained in macaque monkeys and causes zoonotic malaria widely in South East Asia. Transmission of Plasmodium species between vertebrate hosts depends on an insect vector, which is usually the mosquito. The vector is not just a carrier but the definitive host, where sexual reproduction of Plasmodium species occurs, and the parasite's development in the insect is essential for transmission to the next vertebrate host. The range of insect species that can support the critical development of Plasmodium depends on the individual parasite species, but all five Plasmodium species causing malaria in humans are transmitted exclusively by anopheline mosquitoes. Plasmodium species have remarkable genetic flexibility which lets them adapt to alterations in the environment, giving them the potential to quickly develop resistance to therapeutics such as antimalarials and to change host specificity. In this article, selected topics involving the Plasmodium species that cause malaria in humans are reviewed.

Background: Many studies have reported specific adaptations to high altitude, but few studies have focused on physiological variations in high-altitude adaptation in Andean highlanders. This study aimed to investigate the relationships between SpO2 and related factors, including individual variations and sex differences, in Andean highlanders. Methods: The participants were community-dwelling people in La Paz, Bolivia, aged 20 years and over (age range 20-34 years). A total of 50 men and 50 women participated in this study. Height, weight, SpO2, hemoglobin concentration, finger temperature, heart rate, and blood pressure were measured. Information about lifestyle was also obtained by interview. Results: There were individual variations of SpO2 both in men (mean 89.9%, range 84.0-95.0%) and women (mean 91.0%, range 84.0-96.0%). On Student's t test, men had significantly lower heart rate (p = 0.046) and SpO2 (p = 0.030) than women. On the other hand, men had significantly higher SBP (p < 0.001), hemoglobin (p < 0.001), and finger temperature (p = 0.004). In men, multiple stepwise regression analysis showed that a higher SpO2 was correlated with a lower heart rate (β =-0.089, p = 0.007) and a higher finger temperature (β = 0.308, p = 0.030) (r 2 for model = 0.18). In women, a higher SpO2 was significantly correlated with a higher finger temperature (β = 0.391, p = 0.015) (r 2 for model = 0.12). A higher SpO2 was related to a higher finger temperature (β = 0.286, p = 0.014) and a lower heart rate (β =-0.052, p = 0.029) in all participants (r 2 for model = 0.21). Residual analysis showed that individual SpO2 values were randomly plotted.Conclusion: Random plots of SpO2 on residual analysis indicated that these variations were random error, such as biological variation. A higher SpO2 was related to a lower heart rate and finger temperature in men, but a higher SpO2 was related to finger temperature in women. These results suggest that there are individual variations and sex differences in the hemodynamic responses of high-altitude adaptation in Andean highlanders., Journal of Physiological Anthropology, 39(1), art.no.31; 2020

Since 1980, the world has been threatened by different waves of emerging disease epidemics. In the twenty-first century, these diseases have become an increasing global concern because of their health and economic impacts in both developed and resource-constrained countries. It is difficult to stop the occurrence of new pathogens in the future due to the interconnection among humans, animals, and the environment. However, it is possible to face a new disease or to reduce the risk of its spread by implementing better early warning systems and effective disease control and prevention, e.g., effective global surveillance, development of technology for better diagnostics, effective treatments, and vaccines, the global political will to respond to any threats and multidisciplinary collaboration involving all sectors in charge of good health maintenance. In this review, we generally describe some factors related to human activities and show how they can play a role in the transmission and spread of infectious diseases by using some diseases as examples. Additionally, we describe and discuss major factors that are facilitating the spread of the new pandemic known as COVID-19 worldwide.

Background The prevalence of allergic and autoimmune conditions has been steadily increasing in wealthy nations over the past century. One hypothesis put forward to explain this is the Old Friends Hypothesis, which posits that increased hygiene, urbanization, and lifestyle changes have reduced our exposure to parasites and microbes that we co-evolved with, resulting in immune dysregulation. However, research in traditionally living populations, who are exposed to greater parasite and pathogen loads such as those encountered during our evolution, is limited, in part due to a lack of minimally invasive, field-friendly biomarkers of autoimmune disorders. We therefore developed an ELISA to assess positivity for thyroid peroxidase autoantibody (TPO-Ab), an indicator of autoimmune thyroid disease, based on dried blood spot (DBS) samples. Results We used the Accubind anti-thyroid peroxidase test system to screen our validation samples comprising matched fingerprick DBS, venous DBS, and plasma samples from 182 adults. After confirming that we had TPO-Ab-positive individuals in our validation sample (n = 12), we developed an indirect ELISA to measure TPO-Ab levels from one 3-mm DBS punch. The sensitivity and specificity of our assay for DBS samples ranged from 91.7–100% and 98.2–98.8%, respectively, using a cut-off value of ≥ 26 IU/mL. Intra-assay reliability for duplicate quality control DBS punches was 5.2%, while inter-assay reliability ranged from 11.5–24.4% for high, medium, and low DBS controls. Dilutional linearity ranged from 80 to 120%, and spike and recovery experiments indicated that the DBS matrix does not interfere with the detection of TPO-Ab. TPO-Ab levels remained stable in DBS samples stored at − 28 °C or − 80 °C, but decreased over time in DBS samples kept at 22 °C or at 37 °C. Conclusions We developed an in-house, kit-independent indirect ELISA assay to determine individuals’ TPO-Ab positivity based on dried blood spots, representing a cost-effective method with potential applications in a range of research settings.

Background Ground golf is a popular sport among the elderly in Japan. Several types of exercise can reduce the body's mean arterial pressure (MAP), but little is known about how ground golf affects the MAP. We investigated the effects of ground golf on the MAP and the oxygen uptake ($$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$V̇O2) in a healthy elderly population. Participants and methods Thirteen elderly Japanese people (3 males and 10 females, mean age of 66 years) participated. All participants played 8 holes of ground golf 6 times, as game (G)1 to G6. The MAP, heart rate (HR), and $$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$V̇O2 were measured at rest and every 5 min during each game. Results A linear trend analysis revealed that participants’ MAP values progressively decreased as each game proceeded with marginal differences (p = 0.054). There were no significant differences in HR between at rest and any of the games. The $$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$V̇O2 during the games (except for G6) were significantly higher than that at-rest (p < 0.05). The resting MAP values were negatively associated with the ground golf-induced changes in MAP (r = 0.786, p = 0.001). The participants with greater changes in $$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$V̇O2 during the games showed significantly greater reductions in MAP (r = 0.276, p = 0.043). Conclusions Playing ground golf reduced the participants’ MAP and increased their $$ \dot{\mathrm{V}}{\mathrm{O}}_2 $$V̇O2. Participants with higher resting MAP experienced greater reductions in MAP by playing ground golf, which suggests that ground golf can be a useful recreational sport for the elderly.

Background Early onset of menarche is one of the most important factors for breast cancer and other associated health hazards. The aim of this study was to investigate the early age at menarche and its associated factors in school girls (age, 10–12 years) in Rajshahi District, Bangladesh. Methods Data was collected from Rajshahi District, Bangladesh, using multistage random sampling. Independent sample t test and binary logistic regression model were used in this study. A total number of 386 school girls aged 10–12 years were considered as a sample for this study. Results This study revealed that more than 48% girls already attained menarche within the age of 12 years, among them 25.6%, 41.0%, and 58.3% girls experienced menarche at the age of 10, 11, and 12 years, respectively. It was observed that the menarcheal girls were significantly taller (p < 0.01) and heavier (p < 0.01) than non-menarcheal girls. The menarcheal girls’ mothers were heavier (p < 0.01), shorter (p < 0.01), had more BMI (p < 0.01), reached menarche (p < 0.05) earlier than non-menarcheal girls’ mothers. Menarcheal girls had less number of siblings (p < 0.01) and lower order of birth (p < 0.05) than non-menarcheal girls. After controlling the effect of other factors, multiple logistic regression model demonstrated that obese girls were more likely to attain menarche than under- [AOR = 0.279, CI 95% 0.075–0.986; p < 0.05] and normal [AOR = 0.248, CI 95% 0.082–0.755; p < 0.05] weight girls. Urban school girls had more chance to get menarche than rural school girls at same age (AOR = 0.012, 95% CI 0.003–0.047; p < 0.01). Conclusions Therefore, modern lifestyle changes may have the important factors for early age at menarche of the studied girls in Bangladesh.

Background Recently, attempts have been made to use the pulse rate variability (PRV) as a surrogate for heart rate variability (HRV). PRV, however, may be caused by the fluctuations of left ventricular pre-ejection period and pulse transit time besides HRV. We examined whether PRV differs not only from HRV but also depending on the measurement site. Results In five healthy subjects, pulse waves were measured simultaneously on both wrists and both forearms together with single-lead electrocardiogram (ECG) in the supine and sitting positions. Although average pulse interval showed no significant difference from average R-R interval in either positions, PRV showed greater power for the low-frequency (LF) and high-frequency (HF) components and lower LF/HF than HRV. The deviations of PRV from HRV in the supine and sitting positions were 13.2% and 7.9% for LF power, 24.5% and 18.3% for HF power, and − 15.0% and − 30.2% for LF/HF, respectively. While the average pulse interval showed 0.8% and 0.5% inter-site variations among the four sites in the supine and sitting positions, respectively, the inter-site variations in PRV were 4.0% and 3.6% for LF power, 3.8% and 4.7% for HF power, and 18.0% and 17.5% for LF/HF, respectively. Conclusions These suggest that PRV shows not only systemic differences from HRV but also considerable inter-site variations.

BackgroundThe specific role of the oxytocin receptor (OXTR) gene polymorphisms in emotional support seeking, related to social norms and culturally normative behavior, has been discussed in several studies. Evidence on the association between aggression andOXTRpolymorphisms has also been reported. The goal of the current study was to analyze the effect of theOXTRrs53576 polymorphism, prenatal testosterone effect (second-to-fourth digit ratio, or 2D:4D), and culture on aggression assessed with the Buss-Perry Aggression Questionnaire (BPAQ).MethodsThe data were collected in Russia and Tanzania and included seven ethnic groups of European, Asian, and African origin. The total sample included 1705 adults (837 males, 868 females). All the subjects were evaluated with the BPAQ. As a measure of prenatal androgenization, the second and fourth digits were measured directly from hand, and the digit ratios were calculated. All the participants provided buccal samples, from which genomic DNA was extracted, and theOXTRgene rs53576 polymorphism was genotyped. Statistical analysis was performed using SPSS version 23.0; the alpha level for all analyses was set at 0.05.ResultsThe ethnic group factor was the most significant predictor of ratings on BPAQ (medium effect size for physical aggression, anger and hostility scales, and low for verbal aggression). To study the effect of sex, theOXTRpolymorphism, and prenatal androgenization, we conducted thez-score transformation for BPAQ scales and 2D:4D for each ethnic group and pooled these data into newz-score variables. According to the GLM analysis after leveling the effects of culture (z-transformation), all four scales of BPAQ demonstrated association with sex (main effects), with men scoring higher on physical and verbal aggression and women scoring higher on anger and hostility. Anger and hostility scales were also associated withOXTRpolymorphism and 2D:4D of the right hand. The lowest levels of anger and hostility were observed in individuals with the AA genotype, especially in men.ConclusionsOur data suggest that both oxytocin (OXTRgene polymorphism) and fetal testosterone (2D:4D) may significantly affect emotional (anger) and cognitive (hostility) aggression in humans, given the leveling the role of culture.

Background Dermatoglyphics has been used widely in fields of medicine as a non-invasive diagnostic tool and an early assessment of risk for certain medical conditions. It reflects disturbances in fetal development during early prenatal weeks 14–22 when fingerprints develop. Dermatoglyphic asymmetry has been used to measure developmental instability during a specific period of human fetal development. Thus, the present study was planned to investigate whether digital and palmar dermatoglyphics of chronic kidney disease of unknown origin (CKDu) patients in Sri Lanka are different from healthy people. Methods A case control study was carried out among CKDu patients (90 males, 90 females) from a CKDu endemic area and gender-matched two control groups; one group from a CKDu endemic region (90 males, 90 females) and another group from a CKDu non-endemic region (90 males, 90 females). Dermatoglyphics were obtained using photographic methods. Both qualitative and quantitative dermatoglyphic variables were defined and analyzed according to standard criteria. Both directional (DA) and fluctuating asymmetry (FA) were assessed. Results Several qualitative dermatoglyphic variables had significant association with CKDu. The triradii a1 variable was less evident in palms of CKDu cases in both genders when compared to both control groups. The FA of pattern discordance (right vs left hands) between CKDu cases and control group were significant in several digits. The FA of the ridge count was found significant in several digits, and also significant for A-B ridge count and total ridge count. Conclusion Based on these results, it is proposed that the mechanisms responsible for the development of CKDu might be associated with those responsible for FA observed in CKDu patients. Accordingly, a diagnostic tool based on FA could be developed for predicting risk prior to the development of CKDu.

Background High-resolution ultrasound is being widely used in carpal tunnel examination to understand morphological and biomechanical characteristics of the median nerve and surrounding anatomy structures. Main body Healthy young and elderly men were recruited. The median nerve at proximal wrist region was examined by ultrasound imaging technique. A total of seven wrist angle was examined. Generally, the median nerve cross-sectional area of the elderly group is significantly larger than the young group. Short conclusion Wrist posture in greater flexion or extension caused a larger decrease in the median nerve cross-sectional area across both groups.

Background Recently, more consideration is being given to the beneficial effects of lighting on the maintenance and promotion of the health and well-being of office occupants in built environments. A new lighting technology using Rayleigh scattering has made it possible to simulate a blue sky. However, to date, no studies have examined the possible beneficial effects of such artificial skylights. The aims of this study were to examine the non-visual effects of artificial skylights and conventional fluorescent lights in a simulated office environment and to clarify the feature effects of the artificial skylights. Methods Participants were 10 healthy male adults. Non-visual effects were evaluated based on brain arousal levels (α-wave ratio and contingent negative variation [CNV]), autonomic nervous activity (heart rate variability [HRV]), work performance, and subjective responses during daytime exposure to either an artificial skylight or fluorescent lights, as well as nocturnal melatonin secretion. Results Subjective evaluations of both room lighting-related “natural” and “attractive” items and the “connected to nature” item were significantly higher with the skylight than with the fluorescent lights. Cortical arousal levels obtained from the early component of the CNV amplitude were significantly lower with the skylight than with the fluorescent lights, whereas α-wave ratio and work performance were similar between the two light sources. The HRV evaluation showed that sympathetic nerve tone was lower and parasympathetic nerve tone was higher, both significantly, for the skylight than for the fluorescent lights during daytime. Nocturnal melatonin secretion was significantly greater before and during light exposure at night under the daytime skylight than under the fluorescent lights. Conclusions Our results suggest that artificial skylights have some advantages over conventional fluorescent lights in maintaining ordinary work performance during daytime with less psychological and physiological stress. The findings also suggest that the artificial skylights would enable built environments to maintain long-term comfort and productivity.

Background Adult height can serve as a disease marker. While taller stature has been reported to be linked to a decreased risk of cardiovascular disease (CVD), an influence of the height on CVD is not fully understood in specific populations of Asia, which has a lower incidence of CVD and lower stature than Western populations. Methods We conducted a systematic review using original articles of prospective cohort studies published in English, via the PubMed database, on the relationship between the height and mortality of CVD, including cerebrovascular disease, in Asian people. Results We selected four studies on heart/coronary disease and five studies on cerebrovascular disease. Regarding heart/coronary disease, two studies showed that taller stature was associated with a decreased mortality of heart disease in men or cardiovascular disease in women. The hazard ratios of other studies had not shown a clear significance but a decreased direction of taller stature to the mortality. Regarding cerebrovascular disease, most studies showed that taller stature was associated with a decreased mortality of total cerebrovascular diseases or stroke. In two studies, taller stature showed a decreased mortality of ischemic or hemorrhagic stroke. Conclusions Overall, adult height may be inversely predictive to the mortality of CVD, in particular cerebrovascular disease, in Asian people. While this seems to be a similar trend to that of Westerns, further studies are warranted.

Background It is known that the activities of the mirror system are related to imitation and understanding of the intention of an action. It has been reported that the activity of the mirror system is higher for observations for imitating and understanding the intention of an action than for simple observations. However, observations that facilitate the mirror system’s activities, if they are observations intending to imitate an action or observations for understanding the intention of an action, have not been clarified to date. Methods The types of observations of actions that highly facilitate mirror system activities were investigated. Participants were right-handed university students (N = 23). They observed videos showing hand actions following three types of instructions: (1) to observe the videos intending to understand the intention of the action (action understanding, AU), to observe the videos intending to imitate the hand action (imaginarily imitation, II), and to observe the videos without any intention (observation, OB). Brain waves during observation were measured, and the suppression rate of 8–10 Hz (lower mu/α) and 10–12 Hz (upper mu/α) in the central and occipital regions of the brain was calculated. The rate of suppression was compared among the conditions using a repeated measures analysis of variance for each region. Results There was a main effect of the condition in the central region in 10–12 Hz. The degree of suppression in the AU condition was significantly larger than SO condition (p

Background Bed baths are a daily nursing activity to maintain patients’ hygiene. Those may provide not only comfort but also relaxation. Notably, applying a hot towel to the skin for 10 s (AHT10s) during bed baths helped to reduce the risk of skin tears and provided comfort and warmth in previous studies. However, it is still unclear whether autonomic nervous system is affected by bed baths. Thus, this study investigated the effect on the autonomic nervous activity of applying hot towels for 10 s to the back during bed baths. Methods This crossover study had 50 participants (25 men and women each; average age 22.2 ± 1.6 years; average body mass index 21.4 ± 2.2 kg/m2) who took bed baths with and without (control condition: CON) AHT10s on their back. Skin temperature, heart rate variability (HRV), and blood pressure (BP) were measured. Subjective evaluations and the State-Trait Anxiety Inventory in Japanese were also performed. Results A significant interaction of time and bed bath type on skin surface temperature was observed (p < .001). Regarding the means of skin surface temperature at each measurement time point, those for AHT10s were significantly higher than those for CON. Although the total state-anxiety score significantly decreased in both the bed bath types after intervention, the mean values of comfort and warmth were higher for bed baths with AHT10s than for CON (p < .05) during bed baths; AHT10s was significantly higher in warmth than CON after 15 min (p = .032). The interaction and main effects of time on HRV and BP and that of bed bath type were not significant. Conclusion Bed baths that involved AHT10s caused participants to maintain a higher skin temperature and warmer feeling than under the wiping-only condition; they also provided comfort during the interventions. However, the bed baths with AHT10s did not allow participants to reach a relaxed state; moreover, there was no change in autonomic nerve activity. This may be due to participants’ increased anxiety from skin exposure and the intervention being limited to one part of the body.

Background It is well known that light containing the blue component stimulates the intrinsically photosensitive retinal ganglion cells (ipRGCs) and plays a role in melatonin suppression and pupillary constriction. In our previous studies, we verified that simultaneous exposure to blue and green light resulted in less pupillary constriction than blue light exposure. Hence, we hypothesized that the nonvisual effects of polychromatic white light might be increased by blocking the green component. Therefore, we conducted an experiment using optical filters that blocked blue or green component and examined the nonvisual effects of these lights on pupillary constriction and electroencephalogram power spectra. Methods Ten healthy young males participated in this study. The participant sat on a chair with his eyes facing an integrating sphere. After 10 min of light adaptation, the participant’s left eye was exposed to white pulsed light (1000 lx; pulse width 2.5 ms) every 10 s with a blue-blocking glasses, a green-blocking glasses, or control glasses (no lens), and pupillary constriction was measured. Then, after rest for 10 min, the participant was exposed a continuous white light of 1000 lx with a blue- or green-blocking glasses or control glasses and electroencephalogram was measured. Results Pupillary constriction with the blue-blocking glasses was significantly less than that observed with the green-blocking glasses. Furthermore, pupillary constriction under the green-blocking glasses was significantly greater than that observed with the control glasses. Conclusions A reduction in the green component of light facilitated pupillary constriction. Thus, the effects of polychromatic white light containing blue and green components on ipRGCs are apparently increased by removing the green component.

Background Bright light (BL) has been shown to be effective in enhancing both cognitive and physical performances. Alterations in nighttime melatonin levels have also been observed. However, evaluations of light-induced changes in the preceding biochemical processes are absent. Therefore, the impact of a single morning BL exposure on sensorimotor and visuomotor performance, as well as tryptophan (trp) and trp metabolites, was evaluated in this study. Methods In a crossover design, 33 healthy volunteers were randomly exposed to 30 min of

Background: Thermal sensation is a fundamental variable used to determine thermal comfort and is most frequently evaluated through the use of subjective reports in the field of environmental physiology. However, there has been little study of the relationship between the semantics of the words used to describe thermal sensation and the climatic background. The present study investigates the linguistic differences in thermal reports from native speakers of Bangla and Japanese. Methods: A total of 1141 university students (932 in Bangladesh and 209 in Japan) responded to a questionnaire survey consisting of 20 questions. Group differences between Bangladeshi and Japanese respondents were then tested with a chi-square test in a crosstab analysis using SPSS (version 21). Results: For the Bangla-speaking respondents, the closest feeling of thermal comfort was “neutral” (66.6%) followed by “slightly cool” (10.2%), “slightly cold” (6.0%), “slightly hot” (4.1%), and “cold” (3.8%). For the Japanese respondents, the closest feeling of thermal comfort was “cool” (38.3%) followed by “slightly cool” (20.4%), “neutral” (14.6%), “slightly warm” (13.1%), and “warm” (10.7%). Of the Bangladeshi respondents, 37.7% reported that they were sensitive to cold weather and 18.1% reported that they were sensitive to hot weather. Of the Japanese respondents, 20.6% reported that they were sensitive to cold weather and 29.2% reported that they were sensitive to hot weather. Of the Bangladeshi respondents, 51.4% chose “higher than 29 °C” as hot weather and 38.7% of the Japanese respondents chose “higher than 32 °C” as hot weather. In the case of cold weather, 43.1% of the Bangladeshi respondents selected “lower than 15 °C” as cold weather and 53.4% of the Japanese respondents selected “lower than 10 °C” as cold weather. Conclusions: Most of the Bangla-speaking respondents chose “neutral” as the most comfortable temperature, and most of the Japanese respondents chose “cool.” Most of the Bangladeshi respondents reported that they were sensitive to “cold temperatures,” but most of the Japanese respondents reported that they were sensitive to “hot temperatures.”, Journal of Physiological Anthropology, 36, 23; 2017

Background: Although high-density lipoprotein-cholesterol (HDL) level is inversely correlated with cardiovascular events, HDL is also reported to be positively associated with hypertension, which is a known endothelial impairment factor. Since HDL mediates important protective actions on the vascular endothelium by increasing the number of circulating endothelial progenitor cells (CD34-positive cells), the level of circulating CD34-positive cells should influence the association between HDL and hypertension. Methods: To investigate the association between HDL and hypertension in relation to the level of circulating CD34-positive cells, we conducted a cross-sectional study of 477 elderly men aged 60?69 years who participated in general health checkup. Results: HDL was found to be significantly positively associated with hypertension in subjects with a high level of circulating CD34-positive cells, while no significant association was observed for subjects with low circulating CD34-positive cells. Known cardiovascular risk factors adjusted odds (ORs) and 95% confidence intervals (CIs) of hypertension for increments of one standard deviation (SD) in HDL (13.8 mg/dL) were 1.44 (1.06, 1.96) for subjects with a high level of circulating CD34-positive cells and 0.87 (0.63, 1.19) for subjects with low circulating CD34-positive cells. We also revealed a significant association between HDL level and CD34-positive cell level on hypertension, with fully adjusted p values for the effect of this interaction on hypertension at 0.022. Conclusions: Independent of known cardiovascular risk factors, HDL was found to be positively associated with hypertension in subjects with a high level of circulating CD34-positive cells but not for subjects with low circulating CD34-positive cells., Journal of Physiological Anthropology, 36, 26; 2017

Background Exposure to pulsed light results in non-visual physiological responses in humans. The present study aims to investigate whether such non-visual effects are influenced to a greater extent by the intensity of lighting or by the power (quantity) of lighting. Methods >Twelve healthy young male participants (23 ± 0.3 years, 21–24 age range) were recruited for the present study. Participants were exposed to light of varying levels of intensity and quantity whose frequency was held constant across the conditions, which consisted of exposure to blue (different intensity, constant quantity) and white (constant intensity, different quantity) LEDs. Pupillary constriction, electroencephalogram (EEG) alpha band ratio, subjective sleepiness, concentration and perception of blueness were measured. Results Pupillary constriction and subjective concentration were significantly greater under the high-intensity and short pulse width (HS) condition than under the low-intensity and long pulse width (LL) conditions at three time points during exposure to high-intensity light. However, no significant differences were observed among the results at the three time points during exposure to different quantities of pulsed light. Conclusions The results of the present study indicate that non-visual influences of pulsed light on physiological function are mainly determined not by the quantity but by the intensity of the emitted light, with relatively higher levels of intensity producing more significant physiological changes, suggesting potent excitation of intrinsically photosensitive retinal ganglion cells. Electronic supplementary material The online version of this article (doi:10.1186/s40101-017-0137-7) contains supplementary material, which is available to authorized users.

Background: Human adaptability to cold environment has been focused on in the physiological anthropology and related research area. Concerning the human acclimatization process in the natural climate, it is necessary to conduct a research assessing comprehensive effect of cold environment and physical activities in cold. This study investigated the effect of cold water immersion on the exercise performance and neuromuscular function during maximal and submaximal isometric knee extension. Methods: Nine healthy males participated in this study. They performed maximal and submaximal (20, 40, and 60% maximal load) isometric knee extension pre-and post-immersion in 23, 26, and 34 degrees C water. The muscle activity of the rectus femoris (RF) and vastus lateralis (VL) was measured using surface electromyography (EMG). The percentages of the maximum voluntary contraction (% MVC) and mean power frequency (MPF) of EMG data were analyzed. Results: The post-immersion maximal force was significantly lower in 23 degrees C than in 26 and 34 degrees C conditions (P < 0.05). The post-immersion % MVC of RF was significantly higher than pre-immersion during 60% maximal exercise in 23 and 26 degrees C conditions (P < 0.05). In the VL, the post-immersion % MVC was significantly higher than pre-immersion in 23 and 26 degrees C conditions during 20% maximal exercise and in 26 degrees C at 40 and 60% maximal intensities (P < 0.05). The postimmersion % MVC of VL was significantly higher in 26 degrees C than in 34 degrees C at 20 and 60% maximal load (P < 0.05). The postimmersion MPF of RF during 20% maximal intensity was significantly lower in 23 degrees C than in 26 and 34 degrees C conditions (P < 0.05), and significantly different between three water temperature conditions at 40 and 60% maximal intensities (P < 0.05). The post-immersion MPF of VL during three submaximal trials were significantly lower in 23 and 26 degrees C than in 34 degrees C conditions (P < 0.05). Conclusions: The lower shift of EMG frequency would be connected with the decrease in the nerve and muscle fibers conduction velocity. To compensate for the impairment of each muscle fibers function, more muscle fibers might be recruited to maintain the working load. This might result in the greater amplitude of EMG after the cold immersion.

Background Recently, mist saunas have been used in the home as a new bathing style in Japan. However, there are still few reports on the effects of bathing methods on recovery from muscle fatigue. Furthermore, the effect of mist sauna bathing on human physiological function has not yet been revealed. Therefore, we measured the physiological effects of bathing methods including the mist sauna on recovery from muscle fatigue. Methods The bathing methods studied included four conditions: full immersion bath, shower, mist sauna, and no bathing as a control. Ten men participated in this study. The participants completed four consecutive sessions: a 30-min rest period, a 10-min all out elbow flexion task period, a 10-min bathing period, and a 10-min recovery period. We evaluated the mean power frequency (MNF) of the electromyogram (EMG), rectal temperature (Tre), skin temperature (Tsk), skin blood flow (SBF), concentration of oxygenated hemoglobin (O2Hb), and subjective evaluation. Results We found that the MNF under the full immersion bath condition was significantly higher than those under the other conditions. Furthermore, Tre, SBF, and O2Hb under the full immersion bath condition were significantly higher than under the other conditions. Conclusions Following the results for the full immersion bath condition, the SBF and O2Hb of the mist sauna condition were significantly higher than those for the shower and no bathing conditions. These results suggest that full immersion bath and mist sauna are effective in facilitating recovery from muscle fatigue.

Perinatal depression is an important public health problem affecting 10% to 20% of childbearing women. Perinatal depression is associated with significant morbidity, and has enormous consequences for the wellbeing of the mother and child. During the perinatal period, treatment of depression, which could affect the mother and child during pregnancy and lactation, poses a complex problem for both mother and clinician. Bright light therapy may be an attractive treatment for perinatal depression because it is low cost, home-based, and has a much lower side effect profile than pharmacotherapy. The antidepressant effects of bright light are well established, and there are several rationales for expecting that bright light might also be efficacious for perinatal depression. This review describes these rationales, summarizes the available evidence on the efficacy of bright light therapy for perinatal depression, and discusses future directions for investigation of bright light therapy as a treatment for perinatal depression.

Background This study aimed to present normative reference values of heart rate variability and salivary alpha-amylase in a healthy young male population with a particular focus on their distribution and reproducibility. Methods The short-term heart rate variability of 417 young healthy Japanese men was studied. Furthermore, salivary alpha-amylase was measured in 430 men. The average age of the subjects were 21.9 years with standard deviation of 1.6 years. Interindividual variations in heart rate variability indices and salivary alpha-amylase levels were plotted as histograms. Data are presented as the mean, median, standard deviation, coefficient of variation, skewness, kurtosis, and fifth and 95th percentiles of each physiological index. Results Mean recorded values were heart period 945.85 ms, log-transformed high frequency component 9.84 ln-ms2, log-transformed low frequency component 10.42 ln-ms2, log-transformed low frequency to high frequency ratio 0.58 ln-ratio, standard deviation of beat-to-beat interval 27.17 ms and root mean square of successive difference 37.49 ms. The mean value of raw salivary alpha-amylase was 17.48 U/mL, square root salivary alpha-amylase 3.96 sqrt[U/mL] and log-transformed salivary alpha-amylase 2.65 ln[U/mL]. Log-transformed heart rate variability indices exhibited almost symmetrical distributions; however, time-domain indices of heart rate variability (standard deviation of beat-to-beat interval and root mean square of successive difference) exhibited right-skewed (positive skewness) distributions. A considerable right-skewed distribution was observed for raw salivary alpha-amylase. Logarithmic transformation improved the distribution of salivary alpha-amylase, although square root transformation was insufficient. The day-to-day reproducibility of these indices was assessed using intraclass correlation coefficients. Intraclass correlation coefficients of most heart rate variability and salivary indices were approximately 0.5 to 0.6. Intraclass correlation coefficients of raw salivary markers were approximately 0.6, which was similar to those of heart rate variability; however, log transformation of the salivary markers did not considerably improve their reproducibility. Correlations between sympathetic indicators of heart rate variability and salivary alpha-amylase were not observed. Conclusion Because the sample population examined in this study involved limited age and gender variations, the present results were independent of these factors and were indicative of pure interindividual variation.

The use of herbs as ergogenic aids in exercise and sport is not novel. Ginseng, caffeine, ma huang (also called 'Chinese ephedra'), ephedrine and a combination of both caffeine and ephedrine are the most popular herbs used in exercise and sports. It is believed that these herbs have an ergogenic effect and thus help to improve physical performance. Numerous studies have been conducted to investigate the effects of these herbs on exercise performance. Recently, researchers have also investigated the effects of Eurycoma longifolia Jack on endurance cycling and running performance. These investigators have reported no significant improvement in either cycling or running endurance after supplementation with this herb. As the number of studies in this area is still small, more studies should be conducted to evaluate and substantiate the effects of this herb on sports and exercise performance. For instance, future research on any herbs should take the following factors into consideration: dosage, supplementation period and a larger sample size.