Preliminary study on the effect of sex on skin cooling response during whole body cryostimulation (-110 °C): Modeling and prediction of exposure durations.

In order to determine the required duration of whole-body exposure to extreme cold (-110 °C) in males and females for achieving the same cold-induced response, a mathematical model of skin cooling kinetics was developed. This modeling is derived from the implementation of a new experimental cryotherapy protocol to obtain continuous skin temperature maps over time. Each 3-min whole-body cryostimulation session was divided into six incremental sessions of 30 s carried out over six consecutive days. Seventeen young, healthy subjects (8 males aged 22.6 ±3.0 years and 9 females aged 23.7 ±4.7 years) agreed to participate in this study. The smallest sex-related difference in temperature was found in the trunk area (2.93 °C after 3 min) while the greatest temperature drop was found in the lower limbs (5.92 °C after 3 min). The largest temperature variation was observed between the trunk and the lower limbs, and peaked at 2.67 °C in males and 6.99 °C in females. For both sexes, skin cooling kinetics showed a strong transient exponential type decrease followed by linear regression behavior. It appeared that for achieving the same cold-induced response, the required duration of cryostimulation is longer for males. For example, a trunk skin cooling of -12 °C could be achieved in 125s for females vs 170s for males (+36% longer); for the lower limbs, the same skin cooling magnitude could be reached after 87s for females vs 140s for males (+62% longer).

Affective response to whole-body cryotherapy: Influence of sex, body mass index, age, time of day, and past experience.

OBJECTIVE: Whole-Body Cryotherapy (WBC) has seen a recent surge in popularity with patients with inflammatory conditions, athletes, and even people seeking to improve general health and quality of life. WBC treatment usually requires participation in a dozen of 3-min long sessions. But compliance is considered difficult due to possible cold-induced unpleasant sensations. Based on hedonic psychology assumptions, ratings of pleasure-displeasure experienced during a taks or activity may be important to understand individual differences in attendance. METHODS: Two hundred fifty nine customers from two French cryocenters took the Feeling Scale immediately after their first WBC session. RESULTS: End affect appeared to be negatively valenced (M = -1.85, SD = 1.38, 95 % confidence interval: -2.02 to -1.68). Additional statistical analyses revealed a moderating influence of past experience, in women only. Similarly, BMI was found to be negatively associated with displeasure in women, but not in men. CONCLUSION: These findings are discussed and further research directions are suggested.

Effects of Whole-Body Cryostimulation (-90°C) on Somnolence and Psychological Well-Being in an Older Patient with Restless Legs Syndrome.

BACKGROUND: We aimed at evaluating the feasibility and effects of intense (i.e. -90°C) whole-body cryostimulation (WBC) on somnolence and psychological well-being in an older-adult patient diagnosed with restless legs syndrome (RLS). METHODS: An interrupted time series approach was used in which the efficacy of cryostimulation was evaluated by measuring self-reported fatigue, wake time sleepiness, and well-being several times prior to, during, and after exposure to treatment (i.e. daily 3-min sessions of intense WBC). RESULTS: No adverse event occurred. Reported levels of sleepiness decreased immediately following the beginning of the treatment phase. In the same time, self-reported well-being significantly increased. Effects sizes were of large magnitude. CONCLUSION: In summary, the present study demonstrated that daily exposure to extremely cold air in an enclosed space for 2 weeks was feasible and effective in promoting physical and psychological states in an older patient with sleep disturbances.

Aerodynamic investigation of the thermo-dependent flow structure in the wake of a cyclist.

The main purpose of this study was to assess the influence of the environmental temperature on both the aerodynamic flow evolving around the bicycle and cycling power output. The CFD method was used to investigate the detailed flow field around the cyclist/bicycle system for a constant speed of 11.1 m/s (40 km/h) without wind. In complement, a mathematical model was used to determine the temperature-dependent power output in the range [-10; 40 °C]. The numerical investigation gives valuable information about the turbulent flow field in the cyclist's wake which evolves accordingly the surrounding temperature. A major result of this study is that the areas of overpressure upstream of the cyclist and of underpressure downstream of him are less extensive for a temperature of 40 °C compared to -10 °C. The results suggest that the aerodynamic braking effect of the bicycle is minimized when the air temperature is high, as a lower air density results in a reduction in drag on the cyclist. This study showed that the power required to maintain a constant speed is reduced when the temperature is high, the reason being a lower aerodynamic resistance.

Analysis of the effect of swimmer's head position on swimming performance using computational fluid dynamics.

The aim of this numerical work is to analyze the effect of the position of the swimmer's head on the hydrodynamic performances in swimming. In this initial study, the problem was modeled as 2D and in steady hydrodynamic state. The geometry is generated by the CAD software CATIA and the numerical simulation is carried out by the use of the CFD Fluent code. The standard k-epsilon turbulence model is used with a specific wall law. Three positions of the head were studied, for a range of Reynolds numbers about 10(6). The obtained numerical results revealed that the position of the head had a noticeable effect on the hydrodynamic performances, strongly modifying the wake around the swimmer. The analysis of these results made it possible to propose an optimal position of the head of a swimmer in underwater swimming.

Aerodynamic study of time-trial helmets in cycling racing using CFD analysis.

The aerodynamic drag of three different time-trial cycling helmets was analyzed numerically for two different cyclist head positions. Computational Fluid Dynamics (CFD) methods were used to investigate the detailed airflow patterns around the cyclist for a constant velocity of 15 m/s without wind. The CFD simulations have focused on the aerodynamic drag effects in terms of wall shear stress maps and pressure coefficient distributions on the cyclist/helmet system. For a given head position, the helmet shape, by itself, obtained a weak effect on a cyclist's aerodynamic performance (<1.5%). However, by varying head position, a cyclist significantly influences aerodynamic performance; the maximum difference between both positions being about 6.4%. CFD results have also shown that both helmet shape and head position significantly influence drag forces, pressure and wall shear stress distributions on the whole cyclist's body due to the change in the near-wake behavior and in location of corresponding separation and attachment areas around the cyclist.

Should whole body cryotherapy sessions be differentiated between women and men? A preliminary study on the role of the body thermal resistance.

The aim of this study was to investigate how body thermal resistance between sexes evolves over time in the recovery period after a WBC session and to show how this parameter should be considered as a key parameter in WBC protocols. Eighteen healthy participants volunteered for the study (10 males and 8 females). Temperature (core and skin) were recorded pre- and post (immediately and every 5 min until 35 min post) exposure to a single bout of WBC (30 s at -60 °C, 150 s at -110 °C). From both core and skin temperatures a bio-heat transfer model was applied which led to the analytical formulation of the body thermal resistance. An unsteady behavior presenting a similar time-evolution trend in the body insulative response is shown for both females and males, possibly due to the vasodilatation process following an intense peripheral vasoconstriction during the extreme cold. Females present a 37% higher inner thermal resistance than males when reaching an asymptotical thermal state at rest due to a higher concentration of body fat percentage. Adiposity of tissues inherent in fat mass percentage appears to be a key parameter in the body thermal resistance to be taken into account in the definition of appropriate protocols for males and females. The conclusions of this preliminary study suggest that in order to achieve the same skin effects on temperature and consequently to cool efficiency tissues in the same way, the duration of cryotherapy protocols should be shorter when considering female compared to male.

Effect of whole body cryotherapy interventions on health-related quality of life in fibromyalgia patients: A randomized controlled trial.

INTRODUCTION: Although fibromyalgia syndrome (SFM) affects 2-4 percent of adults, research has not identified a preferred therapeutic option for patients worldwide yet. Based on recent findings, it can be expected that whole body cryotherapy can improve health-reported quality of life by alleviating the symptoms of musculoskeletal pain and fatigue. OBJECTIVE: Our aim was to determine whether whole body cryotherapy only can result in improved perceived health and quality of life in fibromyalgia patients. METHODS: 24 patients with fibromyalgia diagnosis were randomized into 2 groups (n=11 in the whole body cryotherapy group, n=13 in the control group). In the whole body cryotherapy group, 10 sessions of whole body cryotherapy were performed (in addition to usual care) in a standard cryotherapy room over a duration of 8days. Subjects in the control group did not change anything in their everyday activities. Quality of life was assessed just before and one month after treatment. RESULTS: Compared with the control group, patients in the whole body cryotherapy group reported significantly improved for health-reported quality of life. These effects lasted for at least one month following intervention. CONCLUSION: Based on these findings, whole body cryotherapy can be recommended as an effective clinically adjuvant approach in the improvement of health-related quality of life in fibromyalgia patients.

Medical Infrared Thermography assistance in the surgical treatment of axillary Hidradenitis Suppurativa: A case report.

BACKGROUND: The purpose of this case report is to highlight for the first time the way Medical Infrared Thermography can be a helpful tool to assist the surgeon in the surgical treatment of Hidradenitis Suppurativa inflammatory disease. METHODS: A 36-year-old man with a 7-year history of Hidradenitis Suppurativa presented inflammatory nodules in the left axilla area corresponding to Hurley stage II. Choice is made to surgically treat this patient using a wide excision protocol combined with a postoperative second intention healing. For the study purpose, an IR FLIR SC620 camera (FLIR Systems, Wilsonville, OR), having a high resolution pixel detector of 640×480 pixels for greater accuracy and higher resolution, has been used. RESULTS: For the first time in the literature, this case report on HS disease supports the idea that real-time medical infrared thermography may be helpful in establishing the true extent of disease preoperatively in the surgical room and in a similar manner, that this technique allows the surgeon to ensure all diseased lesions are removed during surgery. CONCLUSIONS: At least, medical infrared thermography seems to be a powerful tool to control the final wide surgical wound, in order to minimize recurrence risk of such a disease.

Numerical investigation of the early flight phase in ski-jumping.

The purpose of this study is to develop a numerical methodology based on real data from wind tunnel experiments to investigate the effect of the ski jumper's posture and speed on aerodynamic forces in a wide range of angles of attack. To improve our knowledge of the aerodynamic behavior of the ski jumper and his equipment during the early flight phase of the ski jump, we applied CFD methodology to evaluate the influence of angle of attack (α=14°, 21.5°, 29°, 36.5° and 44°) and speed (u=23, 26 and 29m/s) on aerodynamic forces in the situation of stable attitude of the ski jumper's body and skis. The standard k-ω turbulence model was used to investigate both the influence of the ski jumper's posture and speed on aerodynamic performance during the early flight phase. Numerical results show that the ski jumper's speed has very little impact on the lift and drag coefficients. Conversely, the lift and drag forces acting on the ski jumper's body during the early flight phase of the jump are strongly influenced by the variations of the angle of attack. The present results suggest that the greater the ski jumper's angle of inclination, with respect to the relative flow, the greater the pressure difference between the lower and upper parts of the skier. Further studies will focus on the dependency of the parameters with both the angle of attack α and the body-ski angle ß as control variables. It will be possible to test and optimize different ski jumping styles in different ski jumping hills and investigate different environmental conditions such as temperature, altitude or crosswinds.

Cardiac angiotensin II formation in the clinical course of heart failure and its relationship with left ventricular function.

In 76 patients with heart failure (HF) (New York Heart Association [NYHA] classes I through IV) and in 15 control subjects, cardiac angiotensin II (Ang II) generation and its relationship with left ventricular function were investigated by measuring aorta-coronary sinus concentration gradients of endogenous angiotensins and in a part of patients by studying (125)I-labeled Ang I kinetics. Gene expression and cellular localization of the cardiac renin-angiotensin system components, the density of AT(1) and AT(2) on membranes and isolated myocytes, and the capacity of isolated myocytes for synthesizing the hypertrophying growth factors insulin-like growth factor-I (IGF-I) and endothelin (ET)-1 were also investigated on 22 HF explanted hearts (NYHA classes III and IV) and 7 nonfailing (NF) donor hearts. Ang II generation increased with progression of HF, and end-systolic wall stress was the only independent predictor of Ang II formation. Angiotensinogen and angiotensin-converting enzyme mRNA levels were elevated in HF hearts, whereas chymase levels were not, and mRNAs were almost exclusively expressed on nonmyocyte cells. Ang II was immunohistochemically detectable both on myocytes and interstitial cells. Binding studies showed that AT(1) density on failing myocytes did not differ from that of NF myocytes, with preserved AT(1)/AT(2) ratio. Conversely, AT(1) density was lower in failing membranes than in NF ones. Ang II induced IGF-I and ET-1 synthesis by isolated NF myocytes, whereas failing myocytes were unable to respond to Ang II stimulation. This study demonstrates that (1) the clinical course of HF is associated with progressive increase in cardiac Ang II formation, (2) AT(1) density does not change on failing myocytes, and (3) failing myocytes are unable to synthesize IGF-I and ET-1 in response to Ang II stimulation.

Skin-friction drag analysis from the forced convection modeling in simplified underwater swimming.

This study deals with skin-friction drag analysis in underwater swimming. Although lower than profile drag, skin-friction drag remains significant and is the second and only other contribution to total drag in the case of underwater swimming. The question arises whether varying the thermal gradient between the underwater swimmer and the pool water may modify the surface shear stress distribution and the resulting skin-friction drag acting on a swimmer's body. As far as the authors are aware, such a question has not previously been addressed. Therefore, the purpose of this study was to quantify the effect of this thermal gradient by using the integral formalism applied to the forced convection theory. From a simplified model in a range of pool temperatures (20-30 degrees C) it was demonstrated that, whatever the swimming speeds, a 5.3% reduction in the skin-friction drag would occur with increasing average boundary-layer temperature provided that the flow remained laminar. However, as the majority of the flow is actually turbulent, a turbulent flow analysis leads to the major conclusion that friction drag is a function of underwater speed, leading to a possible 1.5% reduction for fast swimming speeds above 1m/s. Furthermore, simple correlations between the surface shear stress and resulting skin-friction drag are derived in terms of the boundary-layer temperature, which may be readily used in underwater swimming situations.

Analysis and excision of ring-opened phosphoramide mustard-deoxyguanine adducts in DNA.

The reaction products formed by reacting deoxyguanosine with phosphoramide mustard at pH 7.4 have been analyzed by high-performance liquid chromatography and Schiff's reaction. The adducts consisted of five fractions of phosphoramide mustard-imidazole ring-opened deoxyguanosine complexes and one fraction of each of intact phosphoramide mustard-deoxyguanosine and phosphoramide mustard-dideoxyguanosine complexes. Thus, contrary to views held previously, the imidazole ring of alkylated guanine can undergo fission at physiological pH. Schiff's reaction suggests that some fractions of phosphoramide mustard-ring-opened deoxyguanosine adducts contain formyl groups, while others do not. When DNA containing phosphoramide mustard-ring-opened guanine adducts was treated with formamidopyrimidine-DNA glycosylase, there was enzymatic removal of formylated ring-opened guanine adducts. The quantification of the full amount of ring-opened guanine released by formamidopyrimidine-DNA glycosylase was precluded by the limitations of our assay system, which requires that any two ring-opened guanines cross-linked by phosphoramide mustard be both excised in order to be detected.

Theoretical modeling of time-dependent skin temperature and heat losses during whole-body cryotherapy: A pilot study.

This article establishes the basics of a theoretical model for the constitutive law that describes the skin temperature and thermolysis heat losses undergone by a subject during a session of whole-body cryotherapy (WBC). This study focuses on the few minutes during which the human body is subjected to a thermal shock. The relationship between skin temperature and thermolysis heat losses during this period is still unknown and have not yet been studied in the context of the whole human body. The analytical approach here is based on the hypothesis that the skin thermal shock during a WBC session can be thermally modelled by the sum of both radiative and free convective heat transfer functions. The validation of this scientific approach and the derivation of temporal evolution thermal laws, both on skin temperature and dissipated thermal power during the thermal shock open many avenues of large scale studies with the aim of proposing individualized cryotherapy protocols as well as protocols intended for target populations. Furthermore, this study shows quantitatively the substantial imbalance between human metabolism and thermolysis during WBC, the explanation of which remains an open question.

A comparison of nimesulide and paracetamol in the treatment of fever due to inflammatory diseases of the upper respiratory tract in children.

The efficacy and tolerability of nimesulide were compared with those of paracetamol in a nonblind randomised study that recruited 110 children (64 males, 46 females; aged 3 to 6 years) with inflammation of the upper respiratory tract and fever. Nimesulide suspension (1.5 mg/kg 3 times daily) or paracetamol syrup (10 mg/kg 4 times daily) were administered orally until fever resolved. Body temperature was recorded and local pain and general discomfort assessed. Three patients treated with nimesulide and 6 patients treated with paracetamol withdrew from the study as a result of adverse events, and 1 paracetamol-treated patient discontinued because of a requirement for therapy with steroids. Nimesulide was as effective as paracetamol in reducing fever, local pain, and general discomfort. Nimesulide therefore appears to be at least as effective as paracetamol in terms of antipyretic and anti-inflammatory activity in children with inflammation of the upper respiratory tract and fever.

The European Study of the Epidemiology of Mental Disorders (ESEMeD/MHEDEA 2000) project: rationale and methods.

The European Study of the Epidemiology of Mental Disorders (ESEMeD/MHEDEA 2000) is a new cross-sectional study investigating the prevalence and the associated factors of mental disorders, as well as their effect on health-related quality of life and the use of services in six European countries. This paper describes the rationale, methods and the plan for the analysis of the project. A total of 22,000 individuals representative of the non-institutionalized population aged 18 and over from Belgium, France, Germany, Italy, the Netherlands and Spain are being interviewed in their homes. Trained interviewers use a computer-assisted personal interview (CAPI) including the most recent version of the Composite International Diagnostic Interview (CIDI, 2000), a well-established epidemiological survey for assessing mental disorders. This is the first international study using the standardized up-to-date methodology for epidemiological assessment. Sizeable differences in prevalence, impact and level of need that is met by the health services are expected. The analysis of these differences should facilitate the monitoring of ongoing mental health reform initiatives in Europe and provide new research hypotheses.

Comparison of bronchial responses to ultrasonically nebulized distilled water, exercise, and methacholine in asthma.

We compared the responses to inhaled methacholine, ultrasonically nebulized distilled water, and exercise in 25 subjects with atopic asthma. The methacholine inhalation test and challenges with distilled water and exercise were performed on three separate days 48 hours apart. Bronchial responsiveness to methacholine and ultrasonically nebulized distilled water was measured as the concentration of methacholine (PC20M) and the volume output of the ultrasonic nebulizer (PO20 UNDW) producing a 20 percent fall in the forced expiratory volume in one second (FEV1). The response to exercise was expressed as the percentage of fall in FEV1 from the value before exercise. Seventeen subjects showed a fall in FEV1 of more than 20 percent after exercise. Eight subjects had a stimulus-response curve to distilled water that was flat up to the maximal volume output from the nebulizer, but only four of them also showed no significant response to exercise. The response to exercise correlated better with PO20 UNDW (r = -0.66; p less than 0.01) than with PC20M (r = -0.19; p greater than 0.5) in those responding to distilled water. In all of the tested subjects, exercise-induced bronchoconstriction correlated with PC20M (r = -0.61; p less than 0.01). The mean PC20M was significantly lower in the subjects with a significant response to distilled water and exercise (p less than 0.001 and p less than 0.0001, respectively). We concluded that ultrasonically nebulized distilled water and exercise provoke significant bronchoconstriction in the subjects with more severe nonspecific bronchial hyperresponsiveness. The correlation found between the two stimuli supports the hypothesis that they act by similar mechanisms.

Intraventricular streptokinase infusion in acute post-haemorrhagic hydrocephalus.

Neonatal post-haemorrhagic hydrocephalus is a clinical condition with a high mortality and long-term morbidity. Its clinical management is difficult and not well standardized. We describe the case of a term baby suffering from acute intracranial hypertension caused by an intraventricular and thalamic haemorrhage. In this case, the external ventricular drain inserted to control intracranial pressure was ineffective because of repeated obstructions due to blood clots. Continuous intraventricular infusion of streptokinase of 20,000 U/day allowed quick lysis of the clots, drainage of the cerebrospinal fluid and relief from the coma. Although it did not prevent a permanent ventriculoperitoneal shunt, we obtained reabsorption of the intraventricular haemorrhage without rebleeding complications. We suggest the use of low-dose fibrinolytic infusion through an external drain for the treatment of acute intracranial hypertension following intraventricular haemorrhage in term infants.

Interaction of adenosine 5'-triphosphate with metal ions X-ray structure of ternary complexes containing Mg(II), Ca(II), Mn(II), Co(II), ATP and 2,2'-dipyridylamine.

The X-ray structures of the isomorphous Mg2+, Ca2+, Mn2+ and Co2+ complexes of ATP have been determined. The metal ions are wrapped in hexa-coordination by the alpha, beta and gamma phosphate groups of two ATP molecules thus blocking the interaction of the metal ions with the adenine base. A second metal ion which is fully hydrated, M(H2O)2+(6), is engaged in a strong hydrogen bond with the gamma phosphate group of ATP and suggests a possible step in facilitating the cleavage between the beta and gamma phosphates in phosphoryl transfer reactions.