A modelling framework for local thermal comfort assessment related to bicycle helmet use.

Thermal discomfort due to accumulated sweat increasing head skin wettedness may contribute to low wearing rates of bicycle helmets. Using curated data on human head sweating and helmet thermal properties, a modelling framework for the thermal comfort assessment of bicycle helmet use is proposed. Local sweat rates (LSR) at the head were predicted as the ratio to the gross sweat rate (GSR) of the whole body or by sudomotor sensitivity (SUD), the change in LSR per change in body core temperature (Δtre). Combining those local models with Δtre and GSR output from thermoregulation models, we simulated head sweating depending on the characteristics of the thermal environment, clothing, activity, and exposure duration. Local thermal comfort thresholds for head skin wettedness were derived in relation to thermal properties of bicycle helmets. The modelling framework was supplemented by regression equations predicting the wind-related reductions in thermal insulation and evaporative resistance of the headgear and boundary air layer, respectively. Comparing the predictions of local models coupled with different thermoregulation models to LSR measured at the frontal, lateral and medial head under bicycle helmet use revealed a large spread in LSR predictions predominantly determined by the local models and the considered head region. SUD tended to overestimate frontal LSR but performed better for lateral and medial head regions, whereas predictions by LSR/GSR ratios were lower and agreed better with measured frontal LSR. However, even for the best models root mean squared prediction errors exceeded experimental SD by 18-30%. From the high correlation (R > 0.9) of skin wettedness comfort thresholds with local sweating sensitivity reported for different body regions, we derived a threshold value of 0.37 for head skin wettedness. We illustrate the application of the modelling framework using a commuter-cycling scenario, and discuss its potential as well as the needs for further research.

Integrated approaches to testing and assessment for grouping nanomaterials following dermal exposure.

Exposure to different nanoforms (NFs) via the dermal route is expected in occupational and consumer settings and thus it is important to assess their dermal toxicity and the contribution of dermal exposure to systemic bioavailability. We have formulated four grouping hypotheses for dermal toxicity endpoints which allow NFs to be grouped to streamline and facilitate risk assessment. The grouping hypotheses are developed based on insight into how physicochemical properties of NFs (i.e. composition, dissolution kinetics, size, and flexibility) influence their fate and hazard following dermal exposure. Each hypothesis is accompanied by a tailored Integrated Approach to Testing and Assessment (IATA) that is structured as a decision tree and tiered testing strategies (TTS) for each relevant question (at decision nodes) that indicate what information is needed to guide the user to accept or reject the grouping hypothesis. To develop these hypotheses and IATAs, we gathered and analyzed existing information on skin irritation, skin sensitization, and dermal penetration of NFs from the published literature and performed experimental work to generate data on NF dissolution in sweat simulant fluids. We investigated the dissolution of zinc oxide and silicon dioxide NFs in different artificial sweat fluids, demonstrating the importance of using physiologically relevant conditions for dermal exposure. All existing and generated data informed the formulation of the grouping hypotheses, the IATAs, and the design of the TTS. It is expected that the presented IATAs will accelerate the NF risk assessment for dermal toxicity via the application of read-across.

Low-Cost Wearable Fluidic Sweat Collection Patch for Continuous Analyte Monitoring and Offline Analysis.

Sweat sensors allow for new unobtrusive ways to continuously monitor an athlete's performance and health status. Significant advances have been made in the optimization of sensitivity, selectivity, and durability of electrochemical sweat sensors. However, comparing the in situ performance of these sensors in detail remains challenging because standardized sweat measurement methods to validate sweat sensors in a physiological setting do not yet exist. Current collection methods, such as the absorbent patch technique, are prone to contamination and are labor-intensive, which limits the number of samples that can be collected over time for offline reference measurements. We present an easy-to-fabricate sweat collection system that allows for continuous electrochemical monitoring, as well as chronological sampling of sweat for offline analysis. The patch consists of an analysis chamber hosting a conductivity sensor and a sequence of 5 to 10 reservoirs that contain level indicators that monitor the filling speed. After testing the performance of the patch in the laboratory, elaborate physiological validation experiments (3 patch locations, 6 participants) were executed. The continuous sweat conductivity measurements were compared with laboratory [Na+] and [Cl-] measurements of the samples, and a strong linear relationship (R2 = 0.97) was found. Furthermore, sweat rate derived from ventilated capsule measurement at the three locations was compared with patch filling speed and continuous conductivity readings. As expected from the literature, sweat conductivity was linearly related to sweat rate as well. In short, a successfully validated sweat collection patch is presented that enables sensor developers to systematically validate novel sweat sensors in a physiological setting.

The accurate prediction of sweat rate from energy expenditure and air temperature: a proof-of-concept study.

This proof-of-concept study used a web application to predict runner sweat losses using only energy expenditure and air temperature. A field study (FS) of n = 37 runners was completed with n = 40 sweat loss observations measured over 1 h (sweat rate, SR). Predictions were also compared with 10 open literature (OL) studies in which individual runner SR was reported (n = 82; 109 observations). Three prediction accuracy metrics were used: for FS, the mean absolute error (MAE) and concordance correlation coefficient (CCC) were calculated to include a 95% confidence interval [CI]; for OL, the percentage concordance (PC) was examined against calculation of accumulated under- and over-drinking potential. The MAE for FS runners was 0.141 kg [0.105, 0.177], which was less than estimated scale weighing error on 85% of occasions. The CCC was 0.88 [0.82, 0.93]. The PC for OL was 96% for avoidance of both under- and over-drinking and 93% overall. All accuracy metrics and their CIs were below acceptable error tolerance. Input errors of ±10% and ±1 °C for energy expenditure and air temperature dropped the PC to between 84% and 90%. This study demonstrates the feasibility of accurately predicting SR from energy expenditure and air temperature alone. Novelty Results demonstrate that accurate runner SR prediction is possible with knowledge of only energy expenditure and air temperature. SR prediction error was smaller than scale weighing error in 85% of observations. Accurate runner SR prediction could help mitigate the common risks of over- and under-drinking.

Assessment of cutaneous axon-reflex responses to evaluate functional integrity of autonomic small nerve fibers.

Cutaneous autonomic small nerve fibers encompass unmyelinated C-fibers and thinly myelinated Aδ-fibers, which innervate dermal vessels (vasomotor fibers), sweat glands (sudomotor fibers), and hair follicles (pilomotor fibers). Analysis of their integrity can capture early pathology in autonomic neuropathies such as diabetic autonomic neuropathy or peripheral nerve inflammation due to infectious and autoimmune diseases. Furthermore, intraneural deposition of alpha-synuclein in synucleinopathies such as Parkinson's disease can lead to small fiber damage. Research indicated that detection and quantitative analysis of small fiber pathology might facilitate early diagnosis and initiation of treatment. While autonomic neuropathies show substantial etiopathogenetic heterogeneity, they have in common impaired functional integrity of small nerve fibers. This impairment can be evaluated by quantitative analysis of axonal responses to iontophoretic application of adrenergic or cholinergic agonists to the skin. The axon-reflex can be elicited in cholinergic sudomotor fibers to induce sweating and in cholinergic vasomotor fibers to induce vasodilation. Currently, only few techniques are available to quantify axon-reflex responses, the majority of which is limited by technical demands or lack of validated analysis protocols. Function of vasomotor small fibers can be analyzed using laser Doppler flowmetry, laser Doppler imaging, and laser speckle contrast imaging. Sudomotor function can be assessed using quantitative sudomotor axon-reflex test, silicone imprints, and quantitative direct and indirect testing of sudomotor function. More recent advancements include analysis of piloerection (goose bumps) following stimulation of adrenergic small fibers using pilomotor axon-reflex test. We provide a review of the current literature on axon-reflex tests in cutaneous autonomic small fibers.

Evaluation of Quality of Life: Functional Assessment of Chronic Illness Therapy after Thoracic Sympathectomy for Palmar Hyperhidrosis.

BACKGROUND: Primary hyperhidrosis is a condition that significantly decreases the quality of life (QOL). Thoracic sympathectomy is safe and efficient method of treatment in palmar hyperhidrosis. OBJECTIVE: The aim of the study was to evaluate the change in QOL in patients with palmar hyperhidrosis who underwent thoracic sympathectomy. METHODS: The study includes 149 patients (37 men and 112 women) who were treated with bilateral thoracoscopic sympathectomy for primary palmar hyperhidrosis. Subjective and objective evaluation of hyperhidrosis were performed prior to the surgery, 3 and 12 months after the treatment. Control group consists of 305 healthy volunteers (118 men and 187 women). The QOL was measured using Functional Assessment of Chronic Illness Therapy (FACIT) scale. RESULTS: The average level of palmar hyperhidrosis in the study group prior to surgery was 224.69 ± 179.20 mg/min/m2. General QOL (FACIT total) before the surgery was significantly lower in the study group when compared with the control group (66.57 ± 16.33 vs. 91.29 ± 11.13; p < 0.05). Three months after surgery level of hyperhidrosis decreased significantly and remained at similar level 12 months after the procedure (13.55 ± 15.41 mg/min/m2 p < 0.05 and 14.41 ± 18.19 mg/min/m2 p < 0.05, respectively). After thoracoscopic sympathectomy, the QOL increased and did not differ when compared with the control group 3 and 12 months after the surgery (90.28 ± 11.13 vs. 91.29 ± 11.13; p = 0.55 and 89.59 ± 11.34 vs. 91.29 ± 11.13; p = 0.84, respectively). The highest increase was observed in functional well-being domain (32.25%); however, it was also noticeable in other domains. CONCLUSION: Thoracic sympathectomy is an efficient method of treatment in palmar hyperhidrosis which significantly increases patients' QOL especially in a functional domain.

Assessment of sudomotor function.

PURPOSE: To review the currently available literature on clinical autonomic tests of sudomotor function. METHODS: We searched PubMED/MEDLINE for articles on technical principles and clinical applications of sudomotor tests with a focus on their drawbacks and perspectives in order to provide a narrative review. RESULTS: The quantitative sudomotor axon reflex sweat test (QSART) is the most widely used test of sudomotor function. The technique captures pathology with low intra- and inter-subject variability but is limited by technical demands. The thermoregulatory sweat test comprises topographic sweat pattern analysis of the ventral skin surface and allows differentiating preganglionic from postganglionic sudomotor damage when combined with a small fiber test such as QSART. The sympathetic skin response also belongs to the more established techniques and is used in lie detection systems due to its high sensitivity for sudomotor responses to emotional stimuli. However, its clinical utility is limited by high variability of measurements, both within and between subjects. Newer and, therefore, less widely established techniques include silicone impressions, quantitative direct and indirect axon reflex testing, sensitive sweat test, and measurement of electrochemical skin conductance. The spoon test does not allow a quantitative assessment of the sweat response but can be used as bedside-screening tool of sudomotor dysfunction. CONCLUSION: While new autonomic sudomotor function testings have been developed and studied over the past decades, the most were well-studied and established techniques QSART and TST remain the gold standard of sudomotor assessment. Combining these techniques allows for sophisticated analysis of neurally mediated sudomotor impairment. However, newer techniques display potential to complement gold standard techniques to further improve their precision and diagnostic value.

Thermoregulation and markers of muscle breakdown in malignant hyperthermia susceptible volunteers during an acute heat tolerance test.

OBJECTIVES: The study was undertaken to compare the thermal and biochemical responses to a heat tolerance test (HTT) of malignant hyperthermia (MH) susceptible individuals, volunteers who have suffered heat illness (HI) and control volunteers. METHODS: Three groups of male volunteers (n=6 in each group) were recruited to the study: MHS - civilian volunteers previously diagnosed as MH susceptible; EHI - military volunteers with a history of exertional HI; CON - military volunteers with no history of HI or MH. For the HTT, volunteers walked on a treadmill at 60% maximal oxygen uptake in a hot environment. Measurements were made of core and skin temperatures, heat flow, whole body sweat rate and serum lactate, creatine kinase and myoglobin concentrations. RESULTS: There were no differences in deep body temperature, oxygen uptake or serum lactate and creatine kinase concentrations between the three groups. One MHS volunteer and two EHI volunteers failed to achieve thermal balance with rectal temperature continuing to rise throughout the test and reaching 39.5°C, the rectal temperatures of the other volunteers plateaued at a mean (SD) of 38.7 (0.4)°C demonstrating thermal tolerance on this test. Serum myoglobin concentration and the increase in serum myoglobin was higher in MHS than EHI and CON Post HHT (P<0.05). CONCLUSION: MH susceptibility does not always predispose an individual to heat intolerance during an acute HTT, but does appear to increase muscle breakdown. The inclusion of serum myoglobin measurements to a HTT may help to distinguish patients that are potentially MHS, and who otherwise demonstrate thermal tolerance.

Characteristics of patients with acute myocardial infarction contacting primary healthcare before hospitalisation: a cross-sectional study.

BACKGROUND: The characteristics of patients with on-going myocardial infarction (MI) contacting the primary healthcare (PHC) centre before hospitalisation are not well known. Prompt diagnosis is crucial in patients with MI, but many patients delay seeking medical care. The aims of this study was to 1) describe background characteristics, symptoms, actions and delay times in patients contacting the PHC before hospitalisation when falling ill with an acute MI, 2) compare those patients with acute MI patients not contacting the PHC, and 3) explore factors associated with a PHC contact in acute MI patients. METHODS: This was a cross-sectional multicentre study, enrolling consecutive patients with MI within 24 hours of admission to hospital from Nov 2012 until Feb 2014. RESULTS: A total of 688 patients with MI, 519 men and 169 women, were included; the mean age was 66±11 years. One in five people contacted PHC instead of the recommended emergency medical services (EMS), and 94% of these patients experienced cardinal symptoms of an acute MI; i.e., chest pain, and/or radiating pain in the arms, and/or cold sweat. Median delay time from symptom-onset-to-decision-to-seek-care was 2:15 hours in PHC patients and 0:40 hours in non-PHC patients (p<0.01). The probability of utilising the PHC before hospitalisation was associated with fluctuating symptoms (OR 1.74), pain intensity (OR 0.90) symptoms during off-hours (OR 0.42), study hospital (OR 3.49 and 2.52, respectively, for two of the county hospitals) and a final STEMI diagnosis (OR 0.58). CONCLUSIONS: Ambulance services are still underutilized in acute MI patients. A substantial part of the patients contacts their primary healthcare centre before they are diagnosed with MI, although experiencing cardinal symptoms such as chest pain. There is need for better knowledge in the population about symptoms of MI and adequate pathways to qualified care. Knowledge and awareness amongst primary healthcare professionals on the occurrence of MI patients is imperative.

MENOS4 trial: a multicentre randomised controlled trial (RCT) of a breast care nurse delivered cognitive behavioural therapy (CBT) intervention to reduce the impact of hot flushes in women with breast cancer: Study Protocol.

BACKGROUND: Women who have been treated for breast cancer may identify vasomotor symptoms, such as hot flushes and night sweats (HFNS), as a serious problem. HFNS are unpleasant to experience and can have a significant impact on daily life, potentially leading to reduced adherence to life saving adjuvant hormonal therapy. It is known that Cognitive Behavioural Therapy (CBT) is effective for the alleviation of hot flushes in both well women and women who have had breast cancer. Most women with breast cancer will see a breast care nurse and there is evidence that nurses can be trained to deliver psychological treatments to a satisfactory level, whilst also maintaining treatment fidelity. The research team will assess whether breast care nurses can effectively deliver a CBT intervention to alleviate hot flushes in women with breast cancer. METHODS: This study is a multi-centre phase III individually randomised controlled trial of group CBT versus usual care to reduce the impact of hot flushes in women with breast cancer. 120-160 women with primary breast cancer experiencing seven or more problematic HFNS a week will be randomised to receive either treatment as usual (TAU) or participation in the group CBT intervention plus TAU (CBT Group). A process evaluation using May's Normalisation Process Theory will be conducted, as well as practical and organisational issues relating to the implementation of the intervention. Fidelity of implementation of the intervention will be conducted by expert assessment. The cost effectiveness of the intervention will also be assessed. DISCUSSION: There is a need for studies that enable effective interventions to be implemented in practice. There is good evidence that CBT is helpful for women with breast cancer who experience HFNS, yet it is not widely available. It is not yet known whether the intervention can be effectively delivered by breast care nurses or implemented in practice. This study will provide information on both whether the intervention can effectively help women with hot flushes and whether and how it can be translated into routine clinical practice. TRIAL REGISTRATION: ISRCTN 12824632 . Registered 25-01-2017.

Measured and perceived indices of fluid balance in professional athletes. The use and impact of hydration assessment strategies.

BACKGROUND: To determine athletes perceived and measured indices of fluid balance during training and the influence of hydration strategy use on these parameters. METHODS: Thirty-three professional rugby union players completed a 120 minute training session in hot conditions (35°C, 40% relative humidity). Pre-training hydration status, sweat loss, fluid intake and changes in body mass (BM) were obtained. The use of hydration assessment techniques and players perceptions of fluid intake and sweat loss were obtained via a questionnaire. RESULTS: The majority of players (78%) used urine colour to determine pre-training hydration status but the use of hydration assessment techniques did not influence pre-training hydration status (1.025 ± 0.005 vs. 1.023 ± 0.013 g.ml-1, P = .811). Players underestimated sweat loss (73 ± 17%) to a greater extent than fluid intake (37 ± 28%) which resulted in players perceiving they were in positive fluid balance (0.5 ± 0.8% BM) rather than the measured negative fluid balance (-1.0 ± 0.7% BM). Forty-eight percent of players used hydration monitoring strategies during exercise but no player used changes in BM to help guide fluid replacement. CONCLUSION: Players have difficulty perceiving fluid intake and sweat loss during training. However, the use of hydration monitoring techniques did not affect fluid balance before or during training.

Cholinergic urticaria: epidemiology, physiopathology, new categorization, and management.

PURPOSE: The aim of this study was to review the evidence on the epidemiology, physiopathology, categorization, and management of cholinergic urticaria. We specifically focused on several subtypes of cholinergic urticaria and investigated the relationship between cholinergic urticaria and idiopathic anhidrosis. METHODS: Using an integrative approach, we reviewed publications addressing the epidemiology, clinical features, diagnostic approach, physiopathology, subtype classification, and therapeutic approach to cholinergic urticaria. RESULTS: Multiple mechanisms were found to contribute to the development of cholinergic urticaria. This disorder should be classified based on the pathogenesis and clinical characteristics of each subtype. Such a classification system would lead to better management of this resistant condition. In particular, sweating function should be given more attention when examining patients with cholinergic urticaria. CONCLUSIONS: Because cholinergic urticaria is not a homogeneous disease, its subtype classification is essential for selection of the most suitable therapeutic method.

Assessment of the effectiveness of modular clothing protecting against the cold based on physiological tests.

At many workstations in a cold environment, protective clothing provided for the workers is characterized by inadequate thermal insulation, which results in an adverse impact of the cold environment on the worker's body. The purpose of this article is to present developed new ergonomic modular cold protective clothing, which allows for easy adaptation of the thermal insulation of clothing to a worker's individual needs. This clothing was compared in a laboratory study with the clothing having so far been used by workers in a cold environment using physiological and physical measurements, subjective ratings of the thermal state as well as a questionnaire for subjective assessment of the used clothing. These measurements and ratings confirmed that the modular cold protective clothing is more effective in the process of ensuring thermal comfort to the wearer during work in a cold environment than the clothing having so far been used.

Heat stress assessment in artistic glass units.

Heat stress in glass industry is mainly studied in large and highly mechanized manufacturing Units. To the contrary, few studies were carried out in small factories specialized in hand-made products. To stress the need of combined objective and medical surveys in these environments, this paper deals with a simultaneous climatic and physiological investigation of working conditions in artistic crystal glass factories in Tuscany (Italy). The microclimatic monitoring, through a continuous survey has been carried out in early spring. The main physiological parameters (metabolic rate, heart rate, tympanic temperature and water loss) were measured over the whole shifts. The results show that, despite the arduousness of the working conditions, the heat stress levels are physiologically tolerable. The predictions made using the PHS model at the Analysis level described in ISO 15265 agree closely to the observed values, validating the use of PHS model in these conditions. This model was then used to analyse what is likely to be the situation during the summer. It is concluded that the heat constraint will be very high and that some steps must be taken from the spring to monitor closely the exposed workers in the summer and take measures to prevent any heat accident.

Mine rescuers' heat load during the expenditure of physical effort in a hot environment, using ventilated underwear and selected breathing apparatus.

Mine rescuers' heat load under the same physical effort load (25% of the maximal oxygen uptake), using three types of breathing apparatus, in newly developed heat-removing underwear and outerwear was assessed for typical work conditions of mine rescuers, under milder and harsher ambient conditions of 32 and 38 °C, respectively, both at relative humidity of 85% and air velocity of 1.0 m/s. Expending physical effort at the same load while using different kinds of breathing apparatus resulted in a similar heat load. Under both milder and harsher ambient conditions, heat storage and sweating intensity were greater than the average limit value recommended by hygienic standards, which indicates that the use of breathing apparatus significantly hinders heat exchange with the environment. The developed clothing for mine rescuers was highly rated, and was considered by most people to be better than that used currently.

Iodine-Starch test for assessment of hyperhidrosis in amputees, evaluation of different methods of application.

PURPOSE: Hyperhidrosis is a common problem for amputees. The iodine-starch test is frequently used to assess hyperhidrosis, but a method for its application has not been described for amputees. METHODS: We performed an unblinded comparison of the iodine-starch test using various methods to protect the prosthesis in 10 prosthetic limb users with hyperhidrosis. RESULTS: Plastic wrap produced a diffuse pattern of sweating in 70% of subjects. Forty percent had complaints about this method, and 50% experienced leakage of iodine stain onto prosthetic liners. The prosthetic sheath produced a focal or multifocal reaction in 100% of subjects after 10 min of ambulation. Eighty percent had minor leakage onto the liner, and complaints were noted in 10%. The proportion that experienced diffuse sweating was significantly higher in the plastic wrap condition (p = 0.016; difference in proportions = 70%; 95% confidence interval = 32-100%). The prosthetic sock was tested in four subjects and all had at least mild complaints; three had minor leakage onto the liner. Repeated complaints and lack of stain prevention led to discontinuation with this method. CONCLUSIONS: Of the three methods, the sheath produces a focal or multifocal reaction after 10 min of ambulation and tends to cause less subject complaints. It should be the preferred method to apply the iodine-starch test to amputees. Implications for rehabilitation Hyperhidrosis is a common problem in amputees which negatively affects quality of life. The iodine-starch test is commonly used to guide treatment decisions for hyperhidrosis, but a preferred method for applying it in amputees has not been described. This study describes different methods for applying the iodine-starch test. A prosthetic sheath covering should be the preferred method for the iodine-starch test in amputees.

Retroperitoneoscopic lumbar sympathectomy for plantar hyperhidrosis.

OBJECTIVE: The objective of this study was to assess the reduction in quality of life (QoL) caused by the persistence of primary plantar hyperhidrosis (PPH) symptoms and the level of satisfaction in PPH patients after retroperitoneoscopic lumbar sympathectomy (RLS). The efficacy, safety, and procedure of bilateral RLS in both sexes are also described in this study. METHODS: This is a longitudinal study of consecutive patients who sought specific treatment from a private practitioner for severe PPH as classified on the Hyperhidrosis Disease Severity Scale (HDSS) from October 2005 to October 2014. The patients were asked to report the symptoms of PPH experienced in the immediate preoperative period and to complete a standardized QoL questionnaire developed by de Campos at least 12 months after RLS. Disease outcomes, recurrence of symptoms, and any adverse effects of surgery were evaluated after 30 days and at least 12 months after RLS. RESULTS: Lumbar sympathectomy was performed 116 times in 58 patients; 30 days after surgery, PPH was resolved in all patients. Three patients (5.2%) reported transient thigh neuralgia, and 19 (32.7%) reported transient paresthesia in the lower limbs. There were no reports of retrograde ejaculation. At a minimum of 12 months after RLS, 49 of the 58 patients had fully and correctly answered the follow-up questionnaire and noted a mild (HDSS 2) to moderate (HDSS 3) increase in pre-existing compensatory sweating. One patient had a PPH relapse within 6 months. Improvement in QoL due to the resolution of PPH was reported in 98% of the 49 patients. None of the operations necessitated a change in the laparotomy approach, and none of the patients died. CONCLUSIONS: RLS is safe and effective for the treatment of severe PPH in both sexes. There were no reports of retrograde ejaculation after resection of L3 and L4 ganglia. There was a mild to moderate increase in compensatory sweating in about half of the patients, but without any regret or dissatisfaction for having undergone the surgery because of a significant improvement in QoL.

High temperatures and nephrology: The climate change problem. / Altas temperaturas y nefrología: a propósito del cambio climático.

It is well known that climate change greatly affects human health, even though there are few studies on renal outcomes. Heat waves have been found to increase cardiovascular and respiratory morbidity and mortality, as well as the risk of acute renal failure and hospitalisation due to renal diseases, with related mortality. Recurrent dehydration in people regularly exposed to high temperatures seems to be resulting in an unrecognised cause of proteinuric chronic kidney disease, the underlying pathophysiological mechanism of which is becoming better understood. However, beyond heat waves and extreme temperatures, there is a seasonal variation in glomerular filtration rate that may contribute to the onset of renal failure and electrolyte disorders during extremely hot periods. Although there are few references in the literature, serum sodium disorders seem to increase. The most vulnerable population to heat-related disease are the elderly, children, chronic patients, bedridden people, disabled people, people living alone or with little social contact, and socioeconomically disadvantaged people.

Cows exposed to heat stress during fetal life exhibit improved thermal tolerance.

Maternal heat stress during late gestation affects calf function during postnatal life. The objective of the present study was to evaluate whether calves that experience heat stress in utero have altered thermoregulatory responses to acute heat stress later in life. Specifically, the hypothesis was that heat stress in utero would improve the response to acute heat stress at maturity. Females were born to dams exposed to heat stress or cooled during late gestation preceding their birth. All animals were raised postnatally under identical management. Twelve lactating Holstein cows that were exposed to in utero heat stress (HT) and 12 that were exposed to in utero control (CON) were used. A heat stress challenge was conducted in 3 blocks using 4 HT and 4 CON cows matched according to milk yield, stage of lactation, and parity. Each challenge consisted of transfer from a barn with shade and evaporative cooling to one with shade but no additional cooling for 48 h. The challenge was replicated twice for each block. Sweating rate, respiration rate, rectal temperature (RT), and skin temperature were measured on each cow at 0900, 1100, 1300, 1500, and 1700 h for 2 consecutive days. Mean ambient temperature across 6 challenge days was 26.15 ± 4.75°C. Tendencies for differences at 1700 h were observed between treatments for RT (HT: 39.5 ± 0.1; CON: 39.6 ± 0.1°C; = 0.065), however, there was no difference in respiration rate (HT: 77.6 ± 1.6; CON: 79.5 ± 1.6 bpm; = 0.85). Sweating rate for shaved skin (HT: 29.4 ± 2.0; CON: 36.0 ± 2.0 g/mh; = 0.057) and for non-shaved skin (HT: 22.5 ± 1.5; CON: 29.2 ± 1.2 g/mh; = 0.01) differed between groups. However, there was no effect on skin temperature at the shaved location (HT: 36.2 ± 0.2; CON: 36.0 ± 0.2°C; = 0.81), but there was a tendency for differences for the non-shaved area (HT: 35.4 ± 0.2; CON: 34.9 ± 0.2°C; = 0.097). Cows that underwent in utero heat stress had greater skin temperature at 1700 h vs. in utero control cows, which may be because HT cows increased skin perfusion, and consequently greater cooling via conduction. In utero HT cows would then have higher heat loss and reduced core body temperature, which results in lower rectal temperature and lower sweating rate when exposed to heat stress. These results support the hypothesis that heat stress in utero in late gestation increases heat tolerance at maturity by increasing capacity to dissipate heat to maintain core body temperature.

Factors associated with different symptom domains among postmenopausal Saudi women in Riyadh, Saudi Arabia.

OBJECTIVE: To determine factors associated with different symptom domains among postmenopausal Saudi women in Riyadh, Saudi Arabia. METHODS: In a cross-sectional study, interviews were conducted with 542 postmenopausal Saudi women, comprising sociodemographic history, social support, and the Menopause-specific Quality of Life questionnaire. RESULTS: The mean age of participants was 58 (±7.0) years, and the mean age at menopause was 49 (±4.7) years. We found that 41% (n = 224), 14.4% (n = 78), 57% (n = 307), and 12.7% (n = 69) of women reported severe/moderate impact of vasomotor, psychosocial, physical, and sexual symptoms, respectively. Multivariate logistic regression revealed that lacking emotional support was associated with severe/moderate vasomotor (adjusted odds ratio [aOR] 1.5, 95% confidence interval [CI] 1.1, 2.3), psychosocial (aOR 2.0, 95% CI 1.2, 3.4), and physical (aOR 1.7, 95% CI 1.2, 2.6) symptoms. Lack of tangible social support was associated with severe/moderate sexual symptoms (aOR 1.9, 95% CI 1.0, 3.4). In addition, women who worked (aOR 1.8, 95% CI 1.1, 3.2), were obese (aOR 2.0, 95% CI 1.0, 4.1), lived in rented accommodations (aOR 3.9, 95% CI 1.2, 13.1), or had a retired spouse (aOR 1.6, 95% CI 1.0, 2.4) had higher odds for moderate/severe menopausal symptoms. CONCLUSIONS: Establishing educational and counseling programs for postmenopausal women, their spouses, and other family members could improve social support and hence quality of life of postmenopausal women. Effective preventive strategies to deal with modifiable risk factors, such as obesity and work stress, should also be implemented.