Acute stress reduces intraparenchymal lung natural killer cells via beta-adrenergic stimulation

There are lines of evidence that natural killer (NK) cells are sensitive to physical and psychological stress. Alterations in the immune system including NK cells are known to differ among tissues and organs. The effect of stress on the lung immune system, however, has not been well documented in spite of the fact that the lungs always confront viral or bacterial attacks as well as tumour cell metastasis. In this study, we intended to investigate the effect of restraint stress on lung lymphocytes including NK cells. C57BL/6 mice were exposed to 2 h restraint stress. The concentration of plasma epinephrine significantly rose immediately after the release from restraint as compared to home-cage control mice. Flow cytometric analysis revealed that the numbers of most lymphocyte subsets including NK cells were decreased in the lungs and blood but not in the spleen, immediately after restraint stress. Immunohistochemical examination revealed that the number of NK cells was decreased in the intraparenchymal region of the lungs, while the number of alveolar macrophages did not change. The decrease in the number of NK cells in the lungs and blood was reversed by the administration of propranolol, a nonselective beta adrenergic antagonist. Taken together, our findings suggest that acute stress reduces the number of intraparenchymal lung NK cells via activation of beta adrenergic receptors.     

The use of multistate life-table models for improving population health

We demonstrate how incidence, prevalence, remission, mortality(IPRM) models may be constructed on population life-tables,how the incidence of a condition may be calculated, and howthe consequences of demographic changes and public health interventionsmay be predicted. We illustrate the methodology by applyingit to the epidemiology of diabetes, physical inactivity andobesity in New Zealand.     

Loads applied tangential to a fingertip during an object restraint task can trigger short-latency as well as long-latency EMG responses in hand muscles

Electrical stimulation of the digital nerves can cause short- and long-latency increases in electromyographic activity (EMG) of the hand muscles, but mechanical stimulation of primarily tactile afferents in the digits generally evokes only a long-latency increase in EMG. To examine whether such stimuli can elicit short-latency reflex responses, we recorded EMG over the first dorsal interosseous muscle when subjects (n=13) used the tip of the right index finger to restrain a horizontally oriented plate from moving when very brisk tangential forces were applied in the distal direction. The plate was subjected to ramp-and-hold pulling loads at two intensities (a 1-N load applied at 32 N/s or a 2-N load applied at 64 N/s) at times unpredictable to the subjects (mean interval 2 s; trial duration 500 ms). The contact surface of the manipulandum was covered with rayon—a slippery material. For each load, EMG was averaged for 128 consecutive trials with reference to the ramp onset. In all subjects, an automatic increase in grip force was triggered by the loads applied at 32 N/s; the mean onset latency of the EMG response was 59.8±0.9 (mean ± SE) ms. In seven subjects (54%) this long-latency response was preceded by a weak short-latency excitation at 34.6±2.9 ms. With the loads applied at 64 N/s, the long-latency response occurred slightly earlier (58.9±1.7 ms) and, with one exception, all subjects generated a short-latency EMG response (34.9±1.3 ms). Despite the higher background grip force that subjects adopted during the stronger loads (4.9±0.3 N vs 2.5±0.2 N), the incidence of slips was higher—the manipulandum escaped from the grasp in 37±5% of trials with the 64 N/s ramps, but in only 18±4% with the 32-N/s ramps. The deformation of the fingertip caused by the tangential load, rather than incipient or overt slips, triggered the short-latency responses because such responses occurred even when the finger pad was fixed to the manipulandum with double-sided adhesive tape so that no slips occurred.     

透皮给药研究的新进展

透皮给药安全可控，是无创给药的新途径，有着广阔的市场前景。现有的透皮药物限于小分子和低浓度，角质层屏障使大多数药物难以通过或难以达到有效浓度和有效速率。透皮给药的关键在于促进药物渗透，使药物透皮吸收进毛细血管。促渗手段有：使用化学促渗剂；对药物进行化学修饰制成前体药物；使用物理方法；将药物载入载体。这些方法的原理大致分为三种：改变角质层结构；外力驱动药物；将药物进行修饰或包裹。简要地介绍了增强药物透皮的物理方法和载体方法研究的新进展。     

NEAT – non‐exercise activity thermogenesis – egocentric & geocentric environmental factors vs. biological regulation

Non‐exercise activity thermogenesis (NEAT) is the energy expenditure of all physical activities other than volitional sporting‐like exercise. NEAT includes all those activities that render us vibrant, unique and independent beings such as going to work, playing guitar, toe‐tapping and dancing. The factors that account for the 2000 kcal day^?1 variability of NEAT can be categorized as environmental or biological. The environmental determinants of NEAT can be view using one of two models. In the egocentric model we consider a single person as the focus, e.g. ‘my job’. In the geocentric model we consider the ‘environment’ as the focus, e.g. well‐lit and safe walk ways. These models provide us with a theoretical framework to understand NEAT and how best to intervene to promote NEAT. As well as environmental effectors of NEAT, there are also biological regulatory mechanisms that enable us to account for three‐quarters of the biological variance in susceptibility and resistance to fat gain with human over‐feeding. NEAT is likely to be regulated through a central mechanism that integrates NEAT with energy intake and energy stores so that NEAT is activated with over‐feeding and suppressed with under‐feeding. In conclusion, NEAT is likely to serve as a crucial thermoregulatory switch between energy storage and dissipation that is biologically regulated and influenced, and perhaps over‐ridden, by environment. Deciphering the role of NEAT may lead to a better understanding of the pathogenesis, prevention and treatment of obesity.     

Physical parameters in Japanese newborns

Summary A total of 19 physical parameters of the head, face, chest, and the fingers were examined in Japanese 50 male and 50 female newborns, measured 8 to 64 hr after birth. Exceptional values were excluded referring to the estimated mean and standard deviations. Normal values are presented as mean ±2 S.D. for each sex. As compared with Caucasian newborns, the Japanese newborns showed longer inner canthal and shorter outer canthal distances, shorter ear lengths, and longer palm and middle finger lengths.     

Causal dimensions of college students' perceptions of physical symptoms

According to attribution theory, controllability, locus, and stability are important dimensions underlying causal explanations. The extent to which these theoretical dimensions underlie lay explanations for physical symptoms is unclear. Accordingly, in this study, attributes relevant to the lay public were empirically derived using a multidimensional scaling (MDS) procedure. Undergraduates (N=194) provided similarity judgments for 18 potential causes of physical discomfort. The MDS analysis yielded a three-dimensional solution. The first dimension captured the distinction between physical and nonphysical causes. The second dimension distinguished either variable versus stable causes or those that are controllable versus uncontrollable by health care professionals. The third dimension differentiated causes under low versus high personal control. These findings empirically confirm the theoretically proposed dimensions of personal control and stability and suggest the utility of considering the physical/nonphysical and controllability by health care professional distinctions in future work on attributions in the health domain.     

Increase in the proportion of fast-twitch muscle fibres by sprint training in males

Fifteen male physical education students were studied. The subjects trained for 4–6 weeks, 2–3 days per week, on a mechanically braked bicycle ergometer. A training session consisted of repeated 30-s ‘all-out’ sprints on a Wingate bicycle ergometer, on which the brake band of the flywheel was loaded with 75 g kg^-1 body wt, with rest periods of 15–20 min between consecutive sprints. Thigh muscle biopsies were taken before and after the training period and were analysed for fibre types using a myofibrillar ATPase stain. The proportion of type I fibres decreased from 57 to 48% (P < 0.05) and type IIA fibres increased from 32 to 38% (P < 0.05). This study indicates that it is possible to achieve a fibre type transformation with high-intensity training. The effect of two-legged ‘sprint’ training on muscle fibre type composition may be related to a changed pattern of muscle fibre activation (e.g. an increased stimulation frequency). A change in fibre activation frequency may induce an increased synthesis of type II fibre myosin (fast myosin). Hormonal influences such as enhanced adrenergic stimulation of the muscle fibres cannot be excluded as a contributing factor, however.     

环境物理因子的最佳条件的选择

目的：利用黄金数比例规律找出环境物理因子对人体的最佳条件：方法：人体的相当一部分内容与黄金数有着密切的联系，为此把复杂的人体可以简化为比例加破缺的比例实体；环境物理因子：如环境温度、湿度、环境光波和声波以及环境气压和氧分压，当它们处在黄金数比例附近时，会在人体产生和谐合柏作用。结果：环境物理因子选择在黄金数比例附近时，在心理上产生美和舒适感。已经发现，当精神愉快时，人脑电波频率下限(8Hz)和上限(12．9Hz)之比恰为黄金数。结论：环境物理因子的最佳条件是可以选择的。     

Energy Balance,Eating Disorder Risk,and Pathogenic Behaviors Among Athletic Trainers

ContextResearch exists on energy balances (EBs) and eating disorder (ED) risks in physically active populations and occupations by settings, but the EB and ED risk in athletic trainers (ATs) have not been investigated.ObjectiveTo assess ATs'' energy needs, including the macronutrient profile, and examine ED risk and pathogenic behavioral differences between sexes (men, women) and job statuses (part time or full time) and among settings (college or university, high school, nontraditional).DesignCross-sectional study.SettingFree living in job settings.Patients or Other ParticipantsAthletic trainers (n = 46; male part-time graduate assistant ATs = 12, male full-time ATs = 11, female part-time graduate assistant ATs = 11, female full-time ATs = 12) in the southeastern United States.Main Outcome Measure(s)Anthropometric measures (sex, age, height, weight, body composition), demographic characteristics (job status [full- or part-time AT], job setting [college/university, high school, nontraditional], years of AT experience, exercise background, alcohol use), resting metabolic rate, energy intake (EI), total daily energy expenditure (TDEE), EB, exercise energy expenditure, macronutrients (carbohydrates, protein, fats), the Eating Disorder Inventory-3, and the Eating Disorder Inventory-3 Symptom Checklist.ResultsThe majority of participants (84.8%, n = 39) had an ED risk, with 26.1% (n = 12) engaging in at least 1 pathogenic behavior, 50% (n = 23) in 2 pathogenic behaviors, and 10.8% (n = 5) in >2 pathogenic behaviors. Also, 82.6% of ATs (n = 38) presented in negative EB (EI < TDEE). Differences were found in resting metabolic rate for sex and job status (F_1,45 = 16.48, P = .001), EI (F_1,45 = 12.01, P = .001), TDEE (F_1,45 = 40.36, P < .001), and exercise energy expenditure (F_1,38 = 5.353, P = .026). No differences were present in EB for sex and job status (F_1,45 = 1.751, P = .193); χ² analysis revealed no significant relationship between ATs'' sex and EB (= 0.0, P = 1.00) and job status and EB ( = 2.42, P = .120). No significant relationship existed between Daily Reference Intakes recommendations for all macronutrients and sex or job status.ConclusionsThese athletic trainers experienced negative EB, similar to other professionals in high-demand occupations. Regardless of sex or job status, ATs had a high ED risk and participated in unhealthy pathogenic behaviors. The physical and mental concerns associated with these findings indicate a need for interventions targeted at ATs'' health behaviors.