Genetic variation in Wnt/ß-catenin and ER signalling pathways in female and male elite dancers and its associations with low bone mineral density: a cross-section and longitudinal study.

The association of genetic polymorphisms with low bone mineral density in elite athletes have not been considered previously. The present study found that bone mass phenotypes in elite and pre-elite dancers are related to genetic variants at the Wnt/ß-catenin and ER pathways. INTRODUCTION: Some athletes (e.g. gymnasts, dancers, swimmers) are at increased risk for low bone mineral density (BMD) which, if untreated, can lead to osteoporosis. To investigate the association of genetic polymorphisms in the oestrogen receptor (ER) and the Wnt/ß-catenin signalling pathways with low BMD in elite and pre-elite dancers (impact sport athletes). METHODS: The study included three phases: (1) 151 elite and pre-elite dancers were screened for the presence of low BMD and traditional osteoporosis risk factors (low body weight, menstrual disturbances, low energy availability); (2) a genetic association study was conducted in 151 elite and pre-elite dancers and age- and sex- controls; (3) serum sclerostin was measured in 101 pre-elite dancers and age- and sex-matched controls within a 3-year period. RESULTS: Eighty dancers revealed low BMD: 56.3% had at least one traditional osteoporosis risk factor, whereas 28.6% did not display any risk factor (37.2% revealed traditional osteoporosis risk factors, but had normal BMD). Body weight, menstrual disturbances and energy availability did not fully predict bone mass acquisition. Instead, genetic polymorphisms in the ER and Wnt/ß-catenin pathways were found to be risk factors for low BMD in elite dancers. Sclerostin was significantly increased in dancers compared to controls during the 3-year follow-up (p < 0.05). CONCLUSIONS: Elite and pre-elite dancers demonstrate high prevalence of low BMD, which is likely related to genetic variants at the Wnt/ß-catenin and ER pathways and not to factors usually associated with BMD in athletes (body weight, menstrual disturbances, energy deficiency).

Bone mineral density in vocational and professional ballet dancers.

According to existing literature, bone health in ballet dancers is controversial. We have verified that, compared to controls, young female and male vocational ballet dancers have lower bone mineral density (BMD) at both impact and non-impact sites, whereas female professional ballet dancers have lower BMD only at non-impact sites. INTRODUCTION: The aims of this study were to (a) assess bone mineral density (BMD) in vocational (VBD) and professional (PBD) ballet dancers and (b) investigate its association with body mass (BM), fat mass (FM), lean mass (LM), maturation and menarche. METHODS: The total of 152 VBD (13 ± 2.3 years; 112 girls, 40 boys) and 96 controls (14 ± 2.1 years; 56 girls, 40 boys) and 184 PBD (28 ± 8.5 years; 129 females, 55 males) and 160 controls (27 ± 9.5 years; 110 female, 50 males) were assessed at the lumbar spine (LS), femoral neck (FN), forearm and total body by dual-energy X-ray absorptiometry. Maturation and menarche were assessed via questionnaires. RESULTS: VBD revealed lower unadjusted BMD at all anatomical sites compared to controls (p < 0.001); following adjustments for Tanner stage and gynaecological age, female VBD showed similar BMD values at impact sites. However, no factors were found to explain the lower adjusted BMD values in VBD (female and male) at the forearm (non-impact site), nor for the lower adjusted BMD values in male VBD at the FN. Compared to controls, female PBD showed higher unadjusted and adjusted BMD for potential associated factors at the FN (impact site) (p < 0.001) and lower adjusted at the forearm (p < 0.001). Male PBD did not reveal lower BMD than controls at any site. CONCLUSIONS: Both females and males VBD have lower BMD at impact and non-impact sites compared to control, whereas this is only the case at non-impact site in female PBD. Maturation seems to explain the lower BMD at impact sites in female VBD.

Consensus recommendations on training and competing in the heat.

Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimise performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimise performance is to heat acclimatise. Heat acclimatisation should comprise repeated exercise-heat exposures over 1-2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimise dehydration during exercise. Following the development of commercial cooling systems (eg, cooling-vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organisers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimising the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events, for hydration and body cooling opportunities, when competitions are held in the heat.

Consensus recommendations on training and competing in the heat.

Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimize performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimize performance is to heat acclimatize. Heat acclimatization should comprise repeated exercise-heat exposures over 1-2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimize dehydration during exercise. Following the development of commercial cooling systems (e.g., cooling vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organizers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimizing the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events for hydration and body cooling opportunities when competitions are held in the heat.

Human behavioral thermoregulation during exercise in the heat.

The human capacity to perform prolonged exercise is impaired in hot environments. To address this issue, a number of studies have investigated behavioral aspects of thermoregulation that are recognized as important factors in determining performance. In this review, we evaluated and interpreted the available knowledge regarding the voluntary control of exercise work rate in hot environments. Our analysis indicated that: (a) Voluntary reductions in exercise work rate in uncompensable heat aid thermoregulation and are, therefore, thermoregulatory behaviors. (b) Unlike thermal behavior during rest, the role of thermal comfort as the ultimate mediator of thermal behavior during exercise in the heat remains uncertain. By contrast, the rating of perceived exertion appears to be the key perceptual controller under such conditions, with thermal perception playing a more modulatory role. (c) Prior to increases in core temperature (when only skin temperature is elevated), reductions in self-selected exercise work rate in the heat are likely mediated by thermal perception (thermal comfort and sensation) and its influence on the rating of perceived exertion. (d) However, when both core and skin temperatures are elevated, factors associated with cardiovascular strain likely dictate the rate of perceived exertion response, thereby mediating such voluntary reductions in exercise work rate.

Effectiveness of cold water immersion for treating exertional heat stress when immediate response is not possible.

Immediate treatment with cold water immersion (CWI) is the gold standard for exertional heatstroke. In the field, however, treatment is often delayed due to delayed paramedic response and/or inaccurate diagnosis. We examined the effect of treatment (reduction of rectal temperature to 37.5 °C) delays of 5, 20, and 40 min on core cooling rates in eight exertionally heat-stressed (40.0 °C rectal temperature) individuals. We found that rectal temperature was elevated above baseline (P < 0.05) at the end of all delay periods (5 min: 40.08 ± 0.32; 20 min: 39.92 ± 0.40; 40 min: 39.57 ± 0.29 °C). Mean arterial pressure was reduced (P < 0.05) below baseline (92 ± 1.8 mm Hg) after all delay periods (5 min: 75 ± 2.6; 20 min: 74 ± 1.7; 40 min: 70 ± 2.1 mm Hg; P > 0.05). Rectal core cooling rates were similar among conditions (5 min: 0.20 ± 0.01; 20 min: 0.17 ± 0.02; 40 min: 0.17 ± 0.01 °C/min; P > 0.05). The rectal temperature afterdrop following CWI was similar across conditions (5 min: 35.95; 20 min: 35.61; 40 min: 35.87 °C; P > 0.05). We conclude that the effectiveness of 2 °C CWI as a treatment for exertional heat stress remains high even when applied with a delay of 40 min. Therefore, our results support that CWI is the most appropriate treatment for exertional heatstroke as it is capable of quickly reversing hyperthermia even when treatment is commenced with a significant delay.

Does type 1 diabetes alter post-exercise thermoregulatory and cardiovascular function in young adults?

Recent data demonstrated that individuals with type 1 diabetes mellitus (T1DM) exhibit impaired sweating and increased rectal temperature (i.e., heat storage) during exercise compared with healthy controls. Our purpose in this study was to investigate the consequences of T1DM on post-exercise thermal homeostasis. Sixteen participants (eight controls matched with eight T1DM) performed 90 min of cycling followed by 60 min of seated recovery. Esophageal and rectal temperatures, sweating (forearm, chest, and upper back), skin blood flow [forearm and upper back, presented as cutaneous vascular conductance (CVC)], and blood pressure [mean arterial pressure (MAP)] were measured at baseline and throughout recovery. Esophageal temperature was similar during baseline and recovery between groups (P = 0.88). However, rectal temperature was elevated in our T1DM group throughout recovery (P = 0.05). Sweating and CVC were similar between groups at all sites from 10-min post-exercise until the end of recovery (P ≥ 0.16). While absolute MAP was similar between groups (P = 0.43), the overall decrease in MAP post-exercise was greater in controls from 20 min (T1DM: - 8 ± 5 vs control: - 13 ± 6 mmHg, P = 0.03) until the end of recovery. We conclude that despite increased heat storage during exercise, individuals with T1DM exhibit a suppression in heat loss similar to their healthy counterparts during recovery.

Comparative evaluation of xenobiotics in human and dietary milk: persistent organic pollutants and mycotoxins.

Publications produced over the past 20 years regarding the concentration of xenobiotics in human and dietary milk were evaluated, focusing primarily on persistent organic pollutants (e.g. polychlorinated biphenyls, flame retardants), pesticides (e.g organochlorine) and mycotoxins. In general, countries of low industrialization rate present low levels of dietary milk contamination with dioxins compared to those with high rate of industrialization. According to published data, the most common persistent organic pollutants detected in breast and dietary milk are dichlorodiphenyltrichloroethane compounds, hexachlorocyclohexane, and hexachlorobenzene. Even though the potential risks of persistent organic pollutants in human milk have been acknowledged, the beneficial effect of breastfeeding as the optimal food source for newborn babies should not be disregarded. Especially when sharing information with the general public, it should be made clear that the presence of dioxins and persistent organic pollutants in human milk is not an indication for avoiding breastfeeding. The implications of xenobiotics in human and dietary milk is a matter of growing importance and warrants future work given its important health effects.

Exercise and exposure to heat following bovine colostrum supplementation: a review of gastrointestinal and immune function.

Colostrum is the first milk produced by mammalian mothers and is essential for the health and survival of the newborn. Bovine colostrum (BC) has greater concentrations of the bioactive components (i.e. immune and growth factors) than those found in human colostrum. As a result, BC supplementation has been recently adopted by many sport competitors as a means of enhancing immune function as well as improving performance. Improvements in physical performance associated with BC supplementation may stem from the ability of BC to maintain gastrointestinal (GI) integrity by decreasing GI permeability. During exercise in the heat, blood flow to the GI tract is reduced that leads to endotoxin leakage into circulation. Endotoxins, such as lipopolysaccharide, can trigger an inflammatory cascade leading to physiological strain that, in turn, increases heat storage and decreases time to exhaustion. GI permeability is lessened during passive heat stress following BC supplementation, but the influence of BC supplementation on GI function during exercise heat stress remains to be determined. The implications of endotoxemia during exercise in the heat is a matter of growing importance and warrants further study given the global increase in ambient temperatures during sport competitions.

Does adherence to the Mediterranean diet have a protective effect against active and passive smoking?

OBJECTIVE: To investigate the existing evidence about whether adherence to the Mediterranean diet may have a role as an effect modifier of active and passive smoking on human health. STUDY DESIGN: Review. METHODS: An overview of emerging evidence and published studies that cover the interaction between the Mediterranean diet and smoking. RESULTS: Both epidemiological and laboratory studies have shown that the Mediterranean diet has a protective effect against biochemical and molecular processes that lead to cancer, cardiovascular disease and respiratory illness. Based on the high daily intake of vitamins and antioxidants, the Mediterranean diet is comprised of a number of compounds that could alter certain outcomes related to smoking. Studies have indicated that certain diseases attributable to smoking, such as lung cancer, asthma and cardiovascular disease, are inversely associated with certain antioxidants and lipids. CONCLUSIONS: The literature indicates that the existence of a partial interaction between adherence to the Mediterranean diet and the health effects of smoking is possible. Further research is needed to lead to a conclusive statement on this hypothesis.

Effects of exercise and physical activity on depression.

INTRODUCTION: Depression is a very prevalent mental disorder affecting 340 million people globally and is projected to become the leading cause of disability and the second leading contributor to the global burden of disease by the year 2020. AIM: In this paper, we review the evidence published to date in order to determine whether exercise and physical activity can be used as therapeutic means for acute and chronic depression. Topics covered include the definition, classification criteria and treatment of depression, the link between ß-endorphin and exercise, the efficacy of exercise and physical activity as treatments for depression, properties of exercise stimuli used in intervention programs, as well as the efficacy of exercise and physical activity for treating depression in diseased individuals. CONCLUSIONS: The presented evidence suggests that exercise and physical activity have beneficial effects on depression symptoms that are comparable to those of antidepressant treatments.

Heart rate variability responses to a psychologically challenging scuba dive.

AIM: Given the controversy regarding cardiovascular responses and heart rate variability (HRV) in underwater conditions, the authors assessed the combined effect of psychological stress and scuba diving on cardiac autonomic modulation measured through HRV during and following a diving mission. METHODS: Ten healthy adults (three females; seven males; Body Mass Index [BMI] 23.7 + or - 2.1; age 26.4 + or - 2.9) performed a 20-minute dive in a neutral buoyancy water tank (27 degrees C) at a depth of five meters. The dive scenario involved repairing components of a scientific instrument using a high fidelity task mock-up. Data for HRV (three from the time domain and three from the frequency domain) were obtained for 20 minutes prior to (PRE), during (DIVE), and for 20 minutes following (POST) the dive sortie. RESULTS: Heart rate in DIVE was increased when compared to PRE and POST (74 + or - 10 vs. 108 + or - 16 vs. 72 + or - 8 beats x min(-1), respectively). The time domain measure pNN50 (37.3 + or - 16.9 vs. 14.1 + or - 10.1 vs. 22.0 + or - 12.2%, respectively), and the R-R interval (0.72 + or - 0.26 vs. 0.59 + or - 0.11, vs. 0.86 + or - 0.24, respectively) showed a significant decrease in DIVE compared to PRE and POST, while no changes were detected in the frequency domain indices between measurements. During POST, the square root of the mean of squared differences between successive intervals returned to PRE levels, but pNN50 values remained decreased at DIVE levels. CONCLUSIONS: These findings suggest a decrease in parasympathetic indices during a psychologically challenging scuba dive and a delay in vagal reactivation during the 20-minute period following the dive.

Human conscious response to thermal input is adjusted to changes in mean body temperature.

OBJECTIVE AND DESIGN: To detect the dependable criteria of behavioural thermoregulation through modelling temperature fluctuations of individuals allowed to freely manipulate inlet water temperature of a liquid conditioning garment (LCG) during 130 min of passive exposure to -20 degrees C interspersed with a 10 min period of moderate exercise at the 65th minute using a double-blind experiment. PARTICIPANTS: Eleven volunteers (5 women; 23.40 (SD 2.09) years; BMI: 23.24 (SD 2.19)) who lacked previous experience with LCG and cold exposure experiments. RESULTS: Despite variations in core and skin temperatures, thermal comfort, thermal sensation, and mean body temperature did not fluctuate significantly over time. Participants were able to find a desired level of LCG inlet temperature within 25 minutes which was maintained at similar levels until the 65th minute of the cold exposure. During exercise, LCG inlet water temperature decreased significantly. Regression models demonstrated that mean skin temperature and change in mean body temperature were significantly associated with thermal comfort and thermal sensation. Subsequent models revealed that, although all temperature variables were associated with LCG inlet water temperature, the coefficient of determination mainly depended on mean skin temperature and change in mean body temperature. The involvement of skin temperature was anticipated as the liquid conditioning garment was in contact with the skin. CONCLUSIONS: Humans generate conscious thermoregulatory responses in resting and exercise conditions during exposures to cold environments that are aimed towards maintaining a threshold mean body temperature, rather than temperature changes in individual body regions.

Longitudinal preventive-screening cutoffs for metabolic syndrome in adolescents.

OBJECTIVE: To detect metabolic risk factor cutoff points in adolescence for the diagnosis of metabolic syndrome that develops at the age of 17 years (MS17). DESIGN: This study adopted a 6-year design incorporating four data collection time points (TPs). Volunteers were assessed prospectively at the ages of 12, 13, 14 and 17. PARTICIPANTS: A total of 210, 204, 198 and 187 schoolchildren volunteered at the first (TP(1)=12 years old), second (TP2=13 years old), third (TP3=14 years old) and fourth (TP4=17 years old) data collection TP, respectively. MEASUREMENTS: At each data collection TP, anthropometrical, biological and lifestyle data were obtained. Identical protocols were used for each assessment conducted by the same trained investigators. RESULTS: A total of 12% of the participants were diagnosed with MS17, the majority of them being boys (P<0.05). The prevalence of the syndrome increased directly with the degree of obesity. Using body mass index (BMI), adiposity and/or aerobic fitness levels in both genders, MS17 could be correctly diagnosed as early as TP1. No such cutoff points were found for high-density lipoprotein cholesterol, triglycerides, blood pressure and fasting plasma glucose levels. CONCLUSION: With respect to the data presented, it has been established that the calculated longitudinal preventive-screening cutoffs allow successful diagnosis of metabolic syndrome in adolescents using BMI, adiposity or aerobic fitness levels in both sexes. Adoption of such pediatric guidelines may help mitigate future increase in the prevalence of metabolic syndrome.

Contribution of muscular strength in cardiorespiratory fitness tests.

AIM: Reports from laboratory-based studies have revealed a relationship between resistance training and endurance performance in both trained and untrained individuals. The purpose of the present study was to investigate the contribution of lower extremity muscular strength levels in performing cardiorespiratory fitness tests in laboratory, as well as field-based settings. METHODS: Within 2 weeks 38 healthy males (age 21.6+/-2.5 years, body mass index--BMI--24.4+/-2.2) performed three maximal oxygen uptake (VO(2max)) assessments using the 20 m multistage shuttle run test (MSR), the 20 m square shuttle run test (SSR), and a maximal treadmill test (MT) to exhaustion. Data were also obtained from knee flexion and extension isokinetic dynamometry at 60 degrees xs(-1). RESULTS: MSR performance correlated with the peak torque generated from both legs at r=0.63 (P<0.001). The equivalent for SSR was significant at r=0.44 (P<0.05), while MT demonstrated a non-significant positive correlation coefficient (r=0.34, P>0.05). Stepwise regression analyses revealed that the inclusion of leg strength parameters increased the coefficient of determination by 9% (P<0.001) and 4% (P<0.05) in the MSR and SSR, respectively. The MT model was not significantly associated with any of the isokinetic indices studied. CONCLUSIONS: Although moderately significant, the present coefficients suggest that performance in the present field-based cardiorespiratory fitness tasks is affected to a certain extent by lower extremity muscular strength. The latter also demonstrates a positive relationship with laboratory-based performance.

Influence of body heat content on hand function during prolonged cold exposures.

We examined the influence of 1) prior increase [preheating (PHT)], 2) increase throughout [heating (HT)], and 3) no increase [control (Con)] of body heat content (H(b)) on neuromuscular function and manual dexterity of the hands during a 130-min exposure to -20 degrees C (coldEx). Ten volunteers randomly underwent three passive coldEx, incorporating a 10-min moderate-exercise period at the 65th min while wearing a liquid conditioning garment (LCG) and military arctic clothing. In PHT, 50 degrees C water was circulated in the LCG before coldEx until core temperature was increased by 0.5 degrees C. In HT, participants regulated the inlet LCG water temperature throughout coldEx to subjective comfort, while the LCG was not operating in Con. Thermal comfort, rectal temperature, mean skin temperature, mean finger temperature (T(fing)), change in H(b) (DeltaH(b)), rate of body heat storage, Purdue pegboard test, finger tapping, handgrip, maximum voluntary contraction, and evoked twitch force of the first dorsal interosseus muscle were recorded. Results demonstrated that, unlike in HT and PHT, thermal comfort, rectal temperature, mean skin temperature, twitch force, maximum voluntary contraction, and finger tapping declined significantly in Con. In contrast, T(fing) and Purdue pegboard test remained constant only in HT. Generalized estimating equations demonstrated that DeltaH(b) and T(fing) were associated over time with hand function, whereas no significant association was detected for rate of body heat storage. It is concluded that increasing H(b) not only throughout but also before a coldEx is effective in maintaining hand function. In addition, we found that the best indicator of hand function is DeltaH(b) followed by T(fing).

The effect of performance feedback on cardiorespiratory fitness field tests.

We investigated the effects of performance feedback (PF) on predicting maximal oxygen uptake (VO2 max) using the 20 m Multistage Shuttle Run Test (MST) and 20 m Square Shuttle Test (SST). The agreement between these two field tests in relation to laboratory VO2 max was also examined. Forty healthy males (age: 21.5+/-2.3; BMI: 23.7+/-2.0) randomly performed four indirect VO2 max tests; that is the MST and SST, as well as a modified version of MST (MSTMD) and SST (SSTMD). During MST and SST subjects received PF with respect to both test stage and running pace. In contrast, MSTMD and SSTMD incorporated auditory feedback which solely emitted signals regulating the running pace. Participants also performed a laboratory VO2 max treadmill test (TT). ANOVA demonstrated significant mean predicted VO2 max decrements in both MSTMD (p<0.001) and SSTMD (p<0.05) compared to MST and SST, respectively. In predicting TTVO2 max, the '95% limits of agreement' analysis indicated errors equal to 3.6+/-9.6 and 1.4+/-10.3 ml kg-1 min-1 with coefficients of variation of +/-10.0% and +/-10.9%, for MST and MSTMD, respectively. The corresponding '95% limits of agreement' values for SST and SSTMD were 0.1+/-5.0 and -1.1+/-6.1 ml kg-1 min-1 with coefficients of variation of +/-5.4% and +/-6.7%, respectively. It is concluded that the application of PF leads to superior field testing performances.

Modelling atmospheric pollution during the games of the XXVIII Olympiad: effects on elite competitors.

UNLABELLED: The present study investigated the specific atmospheric conditions expected in Athens during the summer of 2004 in relation to the performance of elite athletes. DESIGN: Atmospheric pollution and weather data for the period April 16th to September 30th covering the entire greater Athens area and collected from 1984 to 2003 were used for descriptive statistics and model fitting. The analysis was focused on carbon monoxide (CO), ozone (O3), sulfur dioxide (SO2), nitrogen oxide (NO), nitrogen dioxide (NO2), and particulate matter with a diameter of < 10 microm (PM10). Factor and cluster analysis were used to describe atmospheric pollution in the northern, central, and southern sector of Athens. Generalized estimated equations (GEE) analysis was used to predict mean August 2004 pollutant concentration. Increased concentrations of O3 and PM10 (mean 2003 values: 134.3 +/- 9.3, 44 +/- 1.9 microg/m3, respectively) may generate adverse health and performance effects. The highest O3 values were recorded in the northern Athenian sector during the period June 12th to July 23rd, peaking around mid-day (12:00-18:00) (p < 0.05). The highest PM10 concentrations were recorded in the central Athenian sector during the period August 20th to September 9th, peaking at late afternoon (14:00-22:00) (p < 0.05). Similar concentrations were observed during all days of the week (p > 0.05). GEE approximated mean August 2004 pollutant concentrations similar to: CO: 2.8 (mg/m3), O3: 136, SO2: 24, NO: 134, and NO2: 106 (microg/m3). Concentrations of O3 and PM10 during the XXVIII Olympiad may generate adverse health and performance effects on the cardiovascular function of the elite competitors. (The present manuscript was submitted shortly before the start of the Games and became published after their completion. In this light, the actual pollution rates in Athens during August 2004 are presented in the Note Added in Proof as credence to the statistics used).

Design and control optimization of microclimate liquid cooling systems underneath protective clothing.

The use of protective clothing, whether in space suits, hazardous waste disposal, or sporting equipment, generally increases the risk of heat stress and hyperthermia by impairing the capacity for evaporative heat exchange from the body to the environment. To date the most efficient method of microclimate cooling underneath protective clothing has been via conductive heat exchange from circulating cooling fluid next to the skin. In order to make the use of liquid microclimate cooling systems ((LQ)MCSs) as portable and practical as possible, the physiological and biomedical engineering design goals should be towards maximizing the efficiency of cooling to maintain thermal comfort/neutrality with the least cooling possible to minimize coolant and power requirements. Meeting these conditions is an extremely complex task that requires designing for a plethora of different factors. The optimal fitting of the (LQ)MCSs, along with placement and design of tubing and control of cooling, appear to be key avenues towards maximizing efficiency of heat exchange. We review the history and major design constraints of (LQ)MCSs, the basic principles of human thermoregulation underneath protective clothing, and explore potential areas of research into tubing/fabric technology, coolant distribution, and control optimization that may enhance the efficiency of (LQ)MCSs.

Educational outcomes of a workplace screening program for genetic susceptibility to hemochromatosis.

Education is an essential component of a genetic screening program. Knowledge outcomes were measured after large-scale workplace education and screening for genetic susceptibility to hereditary hemochromatosis. The aim was to assess knowledge of concepts presented, impact of mode of delivery, and knowledge retention. Education in a group setting was delivered via oral or video presentation and knowledge assessed using self-administered questionnaires at baseline, 1 month, and 12 months. Over 60% of 11 679 participants correctly answered all questions at baseline, scoring higher with clinical concepts (disease etiology and treatment) than genetic concepts (penetrance and genetic heterogeneity). Revising the education program significantly increased correct responses for etiology (p < 0.002), whilst modifying the knowledge assessment tool significantly increased correct responses for etiology (p < 0.001) and gene penetrance (p < 0.001). For three of the four concepts assessed, use of video was as effective as oral presentation for knowledge outcomes. A significantly higher proportion of those at increased risk of disease (n = 44) responded correctly at 12 months than did controls (n = 82; p = 0.011 for etiology, p = 0.002 for treatment and p = 0.003 for penetrance). Hence, genetic screening can be successfully offered in a group workplace setting, with participants remembering clinical concepts better than genetic concepts up to 1 year later.