Cutoff value for predicting success in triathlon mixed team relay.

Introduction: The Mixed-Team-Relay (MTR) triathlon is an original race format present on the international scene since 2009, which became an Olympic event at the Tokyo 2020 Games. The aim of this study was to define the probabilities of reaching a victory, a podium, or a finalist rank in a relay triathlon, according to the position of any of the four relayers (Women/Men/Women/Men) during each of the four segments (leg) of the race. Methods: All MTR results from the World Series, Continental Championships, World Championships from 2009 to 2021 and Tokyo 2020 Olympics have been collected. We calculated the set of probability frequencies of reaching a given final state, according to any transient state during the race. All results are compared with a V' Cramer method. Results: The frequency of winning is similar at the end of Leg 1 for TOP1 (first position) and TOP2-3 (second and third positions). Then, a difference in the winning-associated frequencies is first observed after the Bike stage of Leg 2, where 47% of TOP1 athletes will win, vs 13% of the TOP2-3. Discussion: This difference continually increases until the end of the race. Legs 2 and 3 are preponderant on the outcome of the race, the position obtained by each triathlete, especially in swimming and cycling, greatly influences the final performance of the team. Leg 1 allows to maintain contact with the head of the race, while Leg 4 sets in stone the position obtained by the rest of the team.

Effects of a 6-Week Period of Polarized or Threshold Training on Performance and Fatigue in Elite Swimmers.

PURPOSE: To quantify the impact of a polarized distribution of training intensity on performance and fatigue in elite swimmers. METHODS: Twenty-two elite junior swimmers (12 males, age = 17 [3] y, and 10 females, age = 17 [3] y) participated in a crossover intervention study over 28 wk involving 2- × 6-wk training periods separated by 6 wk. Swimmers were randomly assigned to a training group for the first period: polarized (81% in zone 1, blood lactate concentration, [La]b ≤ 2 mmol·L-1; 4% in zone 2, 2 mmol·L-1 < [La]b ≤ 4 mmol·L-1; and 15% in zone 3, [La]b > 4 mmol·L-1) or threshold (65%/25%/10%). Before and after each period, they performed a 100-m maximal swimming test to determine performance, maximal [La]b, and oxygen consumption and an incremental swimming test to determine speed corresponding to [La]b = 4 mmol·L-1 (V4 mmol·L-1). Self-reported indices of well-being were collected with a daily questionnaire. RESULTS: Polarized training elicited small to moderately greater improvement than threshold training on 100-m performance (within-group change ± 90% confidence interval: 0.97% ± 1.02% vs 0.09% ± 0.94%, respectively) with less fatigue and better quality of recovery. There was no substantial gender effect. No clear differences were observed in physiological adaptations between groups. CONCLUSIONS: In elite junior swimmers, a 6-wk period of polarized training induced small improvements in 100-m time-trial performance and, in combination with less perceived fatigue, forms a viable option for coaches preparing such cohorts of swimmers for competition.

Short-term Effects of Diet and Activity Changes on Inflammation and Insulin Resistance.

The present study focused on rapid responses of inflammation markers and insulin resistance to dietary restriction and exercise in inactive patients. 13 obese women were included during a 5-day time frame during which decreases in food intake (-1 378±298 kcal) were associated with 2 exercise sessions (80 and 40 min). Circulating inflammatory biomarkers, insulin resistance index and muscle soreness were measured in fasted conditions. Fasting plasma concentrations of CRP and insulin resistance index decreased over the period (respectively, p=0.02 and p=0.01), concentrations of IL-6 and TNF-α appeared unchanged (p>0.05). Changes in IL-6 (enhanced) and TNF-α (reduced) concentrations following the prolonged exercise differed compared to days with 40 min exercise and days without exercise (p<0.05). Muscle soreness appeared higher after the 80 min than after the 40-min exercise (p=0.01), and were related with IL-6 and CRP concentration changes. A 5-day period combining exercise and diet reduced the insulin-resistance index and the CRP fasting concentrations. The 80-min exercise enhanced IL-6 and lowered TNF-α concentration changes while days without exercise unaffected these cytokines. These exercise effects on cytokines may have benefited to the insulin resistance index. The duration and number of the exercise sessions appeared sufficient for inactive subjects to initiate health benefits without inducing negative effects on inflammation and muscle soreness.

Onset of exercise and diet program in obese women: metabolic and anorexigenic responses related to weight loss and physical capacities.

Perturbations of energy balance induce compensatory processes that may alter expected weight loss. In obese patients, our aim was to investigate the relationships that occurred between fasting plasma concentrations of anorexigenic peptides and metabolic parameters, appetite, physical capacity, and weight loss in the 5 first days of a program associating exercise and caloric reduction. Thirteen obese women were monitored from day 1 to day 5 with 2 exercise sessions in day 2 and day 4. We measured, in a fasted state, changes in body weight, hunger ratings, and plasma concentrations of fatty acids, triglycerides, leptin, insulin, amylin, peptide YY, and insulin-resistance index. Physical performance was assessed by a 6-min walking test. The program resulted in significantly reduced body weight (0.75±0.4 kg; p=0.001), of plasma concentrations of triglycerides, insulin, amylin, peptide YY, and the insulin-resistance index, and also increased fatty acids (p<0.05). Hunger ratings were increased (p<0.05). Program-induced changes in fatty acids, leptin, and insulin concentrations were related to physical performance (r(2)=0.45, 0.59, and 0.52; p<0.05, respectively) and to weight loss (r(2)=0.65, 0.57, 0.55; p<0.05, respectively). Five days of diet and exercise induced weight loss, improved lipid profile, and decreased insulin resistance while hunger ratings increased. Subjects with higher physical capacity lost more weight, presented higher increases in fatty acids and lower changes of leptin and insulin concentrations suggesting a better metabolic flexibility. To reduce the compensatory responses that can occur with energy imbalances, our study supports to account for individual activity level before prescribing weight-loss program associating diet and exercise.

Rugby morphologies: "bigger and taller", reflects an early directional selection.

AIM: The aim of this paper was to investigate the changes over time in anthropometric parameters of young and adult rugby players in France. METHODS: Age, mass and height were collected for 2051 French elite rugby players participating in the championship during the 1988-1989 and the 2008-2009 seasons. The same variables were collected for the best 145 juniors (under 21 years) and 448 U15 (under 15 years) French players for these seasons. Changes in anthropometric parameters were compared according to age, category (back vs. forwards) and season. RESULTS: Over 20 years, adult French rugby backs and forwards have become heavier by 12 kg and 12.3 kg, taller by 5.4 cm and 2.9 cm, respectively. Junior players also became taller and heavier, 6 cm and 9.9 kg for backs and 4.4 cm and 11.1 kg for forwards. U15 backs have gained 5.1 cm and 6.5 kg, and forwards earned 4.7 cm and 4.7 kg. CONCLUSION: Rugby players have become taller and heavier. Their current morphology is the product of a long process of competition and selection. This study demonstrates that this selection of the "large sizes" is already present at a young age.

Similar slow down in running speed progression in species under human pressure.

Running speed in animals depends on both genetic and environmental conditions. Maximal speeds were here analysed in horses, dogs and humans using data sets on the 10 best performers covering more than a century of races. This includes a variety of distances in humans (200-1500 m). Speed has been progressing fast in the three species, and this has been followed by a plateau. Based on a Gompertz model, the current best performances reach 97.4% of maximal velocity in greyhounds to 100.3 in humans. Further analysis based on a subset of individuals and using an 'animal model' shows that running speed is heritable in horses (h(2) = 0.438, P = 0.01) and almost so in dogs (h(2) = 0.183, P = 0.08), suggesting the involvement of genetic factors. Speed progression in humans is more likely due to an enlarged population of runners, associated with improved training practices. The analysis of a data subset (40 last years in 800 and 1500 m) further showed that East Africans have strikingly improved their speed, now reaching the upper part of the human distribution, whereas that of Nordic runners stagnated in the 800 m and even declined in the 1500 m. Although speed progression in dogs and horses on one side and humans on the other has not been affected by the same genetic/environmental balance of forces, it is likely that further progress will be extremely limited.

[High resolution MRI of carotid atherosclerosis: looking beyond the arterial lumen]. / IRM haute résolution de l'athérosclérose carotidienne: au-delà de la lumière artérielle.

Despite advances in diagnosis and treatment, atherosclerosis remains the second cause of death in the world. Due to technical advances, high resolution MRI (HR-MRI) allows depiction of the wall of cervical arteries, especially carotid atherosclerosis. HR-MRI allows visualization of the different components of atherosclerosis: necrotic lipid core, intraplaque hemorrhage, calcifications and fibrous cap. Global plaque volume as well as the volumes of individual plaque components can be calculated. Atherosclerotic plaque structure analysis, along with stenosis measurement, contribute to the stratification of the stroke risk. HR-MRI may also be used to assess treatment efficacy aimed at stabilizing or reducing plaque progression. Beyond the arterial lumen, direct evaluation of vessel wall should modify the management of atherosclerosis in the years to come.

Bluetongue virus detection by two real-time RT-qPCRs targeting two different genomic segments.

The detection of the bluetongue virus (BTV) by conventional methods is especially difficult and labour-intensive. Molecular diagnosis is also complex because of the high genetic diversity between and within the 24 serotypes of BTV. In the present study, two laboratories joined forces to develop and validate two new RT-qPCRs detecting and amplifying BTV segments 1 and 5. The 2 assays detect strains from all 24 serotypes. They both have a detection limit of 0.01 ECE50 and all 114 samples from BTV-free goats, sheep and cattle were negative. The two assays resulted in similar C(t) values when testing biological samples collected in sheep infected experimentally with a field strain of BTV from the Mediterranean basin. On average, the C(t) values obtained with the 2 methods applied to the 24 serotypes were not significantly different from each other, but some moderate to high differences were seen with a few strains. Therefore these two methods are complementary and could be used in parallel to confirm the diagnosis of a possible new introduction of BTV. An RT-qPCR amplifying a fragment of the beta-actin mRNA was also developed and validated as internal control for the bluetongue specific assays. The three assays described allow a reliable and rapid detection of BTV.

Delivery of DNA vaccines by agarose hydrogel implants facilitates genetic immunization in cattle.

The present study demonstrates the interest of two slow-release systems as vaccination tools in cattle. Two experiments show that a first intradermal administration of one DNA vaccine dose combined with the slow-release of a second dose conduct to a priming of the bovine herpesvirus 1-specific immune response similar to the one generated by two discrete administrations 4 weeks apart. The first experiment demonstrates the efficacy of the slow-release system with well-characterized Alzet osmotic pumps, whereas the second experiment extends the same concept with innovative agarose hydrogel implants. These latter implants are cheaper and more convenient than the osmotic pumps or repeated intradermal administrations since they contribute to an efficient priming of the immune response in a single manipulation of the animals.

Uncertainty of measurement for competitive and indirect ELISAs.

A method for the estimation of the uncertainty of measurements for Gaussian outcomes of enzyme-linked immunosorbent assay (ELISA) is described using competitive and indirect foot and mouth disease (FMD) ELISAs. Assay repeatability was determined by random effects analysis of variance, and the normality of the residuals was checked. The standard errors of the individual predicted values were transformed into confidence intervals around the corresponding observed values and further transformed into probabilities of being above/below a cut-off. Logistic regression models were subsequently used to interpolate probability values for the whole range of possible assay values. The uncertainty of measurement of a test result was finally defined as the probability of not observing the same qualitative test result when retesting the same sample. For the competitive ELISA any sample with a percent inhibition 4% above the cut-off value had an uncertainty level (probability of a negative result in the case of retest) below 5%. In the indirect ELISA with a cut-off OD of 0.1, the uncertainty was below 5% for any sample with a normalised OD value above 0.22.

Prime-boost strategies combining DNA and inactivated vaccines confer high immunity and protection in cattle against bovine herpesvirus-1.

DNA vaccines have frequently been associated with poor efficacy in large animals. In the present study, one administration of an inactivated marker vaccine to cattle considerably boosted both humoral and cellular arms of the immune response primed with Bovine herpesvirus-1 (BoHV-1) DNA vaccines encoding glycoprotein D (gD) or gC+gD. Calves vaccinated according to the DNA prime-inactivated boost also showed significantly enhanced virological protection as compared to controls. The 4-logarithms reduction of virus shedding observed in primed-boosted animals was comparable to the one previously reported in calves immunized twice with marker vaccines. Intradermal immunization of cattle with DNA vaccines promoted a Th2-biased immune response but also primed a cellular component that was further boosted by the inactivated vaccine. Individual IgG2 titers of vaccinated calves were significantly correlated to IFN-gamma production. The immunization protocol described in the present study demonstrates the complementarity between DNA and conventional marker vaccines.

Positron emission and computed tomographies in cardiology.

Predicting acute vascular events in vulnerable patients requires new strategies: biomarkers and imaging are among the major options. Adding perfusion and viability data to anatomical informations with MRI, isotopes or MSCT, will dramatically impact on our decisions to diagnose atherosclerotic patients. The present combination of MSCT scanners with PET or conventional scintigraphy enlarges capabilities of calcium scoring and coronary angiography to perfusion imaging. But MSCT alone, easy, accurate and conspicuous, already changed the face of daily practice in cardiology. Screening of very high risk populations and plaque imaging now are under clinical investigations.

Effects of hypervaccination with bovine herpesvirus type 1 gE-deleted marker vaccines on the serological response and virological status of calves challenged with wild-type virus.

Twenty-four calves were immunised four times with gE-deleted infectious bovine rhinotracheitis marker vaccines before being challenged with small doses of wild-type bovine herpesvirus type 1 (BHV-1). The repeated vaccinations induced strong immunity that prevented detectable virus replication and gE-seroconversion after the challenge infection in most of the calves. The hypervaccinated calves that shed virus after the challenge infection showed no delay in gE-seroconversion compared with unvaccinated control calves. Using a sensitive nested PCR, BHV-1 gE sequences could be detected in the trigeminal ganglia of several of the gE-seronegative, challenge-infected calves, possibly indicating the presence of wild-type BHV-1 DNA.

Enhancement of the immune response and virological protection of calves against bovine herpesvirus type 1 with an inactivated gE-deleted vaccine.

Four immunisation protocols based on inactivated and attenuated commercially available marker vaccines for bovine herpesvirus type 1 (BHV-1) were compared. The first group of calves were vaccinated with an attenuated vaccine administered intranasally and an inactivated vaccine injected subcutaneously, four weeks apart; the second group were vaccinated twice with the attenuated vaccine, first intranasally and then intramuscularly; the third group were vaccinated twice subcutaneously with the inactivated vaccine; and the fourth group were vaccinated twice intramuscularly with the attenuated vaccine. A control group of calves were not vaccinated. The cellular and humoral immune responses were highest in the two groups which received at least one injection of the inactivated vaccine. Virological protection was observed in all the vaccinated groups after a challenge infection and reactivation by treatment with dexamethasone, but the calves which received one dose of the inactivated vaccine as a booster or two doses of the inactivated vaccine excreted significantly less of the challenge virus than the calves which were vaccinated only with the attenuated preparation.

Molecular imaging for the diagnosis of high-risk plaque.

Despite advances in our understanding of the pathogenesis of atherosclerosis and new therapeutic modalities, the absence of an adequate method for early detection limits the prevention and treatment of the disease. High-resolution magnetic resonance has recently emerged as one of the most promising techniques for the non-invasive study of atherothrombotic disease, as it can characterize plaque composition and monitor progression. This review of plaque imaging focuses on the most recent technique: "molecular imaging", which uses specific contrast agents targeted to plaque components, and may allow for better stratification of "high-risk" plaque and "high-risk" patients.

Reproducibility of the ventricular synchronization parameters assessed by multiharmonic phase analysis of radionuclide angiography in the normal heart.

Radionuclide angiography (RNA) permits analysis of contractility and conduction abnormalities. We determined the parameters of normal ventricular synchronization, assessed the reproducibility of the technique, and compared first harmonic (1H) and third harmonic (3H) analysis. Forty-four normal subjects (28 men and 16 women) were studied. RNA was performed in left anterior oblique (LAO) and left lateral (LL) projections. The onset (To), mean time (Tm), total contraction time (Tt) for right ventricle (RV) and left ventricle (LV), interventricular time (T(RV-LV) = Tm(LV - Tm(RV)) in LAO, and the apex-to-base time (T(a-b)) in LL were measured on the histograms of the time-activity curve. Reproducibility (R) was tested by studying 26 consecutive patients with two successive RNAs. RV starts contracting 25 ms before LV (To(RV) = 29 +/- 37 ms; To(LV) = 54 +/- 39 ms; mean +/- SD) with a 37 ms longer total contraction time. T(RV-LV) is 3 +/- 16 ms. In LL projection, apex and base contract synchronously: T(a-b) = 2 +/- 16 ms. 3H analysis enlarges all duration parameters (To, Tm and Tt), but does not alter synchronization (deltaT(a-b) and deltaT(RV-LV) between 1H and 3H <1%, p = NS). Reproducibility of the duration (T(tLV) and T(tRv)) and synchronization parameters (T(a-b) and T(RV-LV)) is high (R < or = 2.2%). In conclusion, the simultaneous contraction of right and left ventricles and of apex and base can be quantified by RNA phase analysis with high reproducibility. These results, consistent with published electrophysiological data, provide the basis for further non-invasive investigations of ventricular resynchronization in patients with basal electrical or mechanical asynchrony.

[MRI characterization of atherosclerotic arteries: diagnosis of plaque rupture]. / Caractérisation IRM de la paroi artérielle athéroscléreuse: diagnostic de rupture de plaque.

Plaque stability and its counterpart, vulnerability, depend on the relative amount and morphology of its principal components: lipid core and fibrous cap. Lipids are mainly made of cholesterol esters and cholesterol monohydrates, but phospholipids and triglycerides are also present. Major chemokines, cytokines, enzymes and markers of inflammation are locally produced, which interact and degrade the arterial matrix, but also stimulate smooth muscle cells and osteopontine production. Due to these differences in composition, the lipid cores have various chemical and biophysical properties (with solid, liquid or liquid-crystalline phases), and so has the collagenous cap, which influence imaging parameters. MRI has improved its capacity to characterize arterial tissue. This technique can now discriminate the different components of normal and pathological arterial walls through various endogenous or exogenous contrast: intima, media, adventitia, perivascular fat, lipid core, collagenous cap and calcifications of atheromatous plaques, but also precise the elements of plaque resistance to radial stress, or the various factors of inflammation. In the next years, improvement of resolution, new contrast sequences (diffusion or magnetization transfer) or spectroscopy, will compete to allow for the best discrimination of these usual suspects: "the unstable plaques".

Saline spa water or combined water and UV-B for psoriasis vs conventional UV-B: lessons from the Salies de Béarn randomized study.

OBJECTIVE: To study the effects of UV-B therapy and saline spa water given alone or in combination for the treatment of psoriasis. DESIGN: Randomized, controlled, comparative study with blinded observers. SETTING: Salies de Béarn, saline spa water center located in the southwest of France. PARTICIPANTS: Seventy-one adult patients with psoriasis with a Psoriasis Area and Severity Index (PASI) score greater than 10. INTERVENTION: Patients were randomly assigned to 1 of 3 treatments: spa water alone (group A); UV-B 311-nm phototherapy alone (group B); and a combination of the 2 therapies (group C). The 3 groups were treated on a daily basis 5 days a week for a total of 21 days. MAIN OUTCOME MEASURES: Change in PASI score from baseline as determined by an investigator blinded to randomization; variation in quality of life, adverse effects, and long-term effects (1 year after treatment). RESULTS: Four patients dropped out because of secondary effects. Efficacy was similar in groups B and C, with changes in PASI of -64% and -55%, respectively at 3 weeks. For group A, change in PASI was -29%, thus showing a minor therapeutic effect of saline spa water alone and poor efficacy compared with groups B and C (P<.001). More adverse effects were reported in groups A and C but did not reach significance. Combined saline spa water and UV-B therapy had no sparing effect on UV-B dosages. One year after treatment, no long-term benefit could be attributed specifically to a given regimen, but the patients had overall significantly better PASI scores than at baseline. CONCLUSIONS: Saline spa water alone had a minor therapeutic effect in psoriasis, and the beneficial effect of bathing to enhance phototherapy was not demonstrated.