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1.
Transpl Int ; 34(6): 1123-1133, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33774875

RESUMEN

Multiple days assessments are frequent for the evaluation of candidates to living kidney donation, combined with an early GFR estimation (eGFR). Living kidney donation is questionable when eGFR is <90 ml/min/1.73 m2 (KDIGO guidelines) or 80 ml/min/1.73 m2 (most US centres). However, age-related GFR decline results in a lower eGFR for older candidates. That may limit the number of older kidney donors. Yet, continuing the screening with a GFR measure increases the number of eligible donors. We hypothesized that in-depth screening should be proposed to all candidates with a normal eGFR for age. We compared the evolution of eGFR after donation between three groups of predonation eGFR: normal for age (Sage ) higher than 90 or 80 ml/min/1.73 m2 (S90 and S80, respectively); across three age groups (<45, 45-55, >55 years) in a population of 1825 French living kidney donors with a median follow-up of 5.9 years. In donors younger than 45, postdonation eGFR, absolute- and relative-eGFR variation were not different between the three groups. For older donors, postdonation eGFR was higher in S90 than in S80 or Sage but other comparators were identical. Postdonation eGFR slope was comparable between all groups. Our results are in favour of in-depth screening for all candidates to donation with a normal eGFR for age.


Asunto(s)
Fallo Renal Crónico , Trasplante de Riñón , Tasa de Filtración Glomerular , Humanos , Riñón , Fallo Renal Crónico/cirugía , Donadores Vivos , Persona de Mediana Edad , Nefrectomía
2.
Clin Infect Dis ; 70(10): 2216-2220, 2020 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-31633150

RESUMEN

The burden of nosocomial Pneumocystis infections in transplantation units in France was evaluated through a retrospective survey. Over 12 years, 16 outbreaks occurred, including 13 among renal transplant recipients (RTRs). We performed Pneumocystis jirovecii genotyping in 5 outbreaks, which suggested that specific strains may have been selected by RTRs.


Asunto(s)
Trasplante de Órganos , Pneumocystis carinii , Neumonía por Pneumocystis , Brotes de Enfermedades , Francia/epidemiología , Genotipo , Humanos , Trasplante de Órganos/efectos adversos , Pneumocystis carinii/genética , Neumonía por Pneumocystis/epidemiología , Estudios Retrospectivos , Encuestas y Cuestionarios
3.
Kidney Int ; 98(6): 1568-1577, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33137341

RESUMEN

End stage kidney disease increase the risk of COVID-19 related death but how the kidney replacement strategy should be adapted during the pandemic is unknown. Chronic hemodialysis makes social distancing difficult to achieve. Alternatively, kidney transplantation could increase the severity of COVID-19 due to therapeutic immunosuppression and contribute to saturation of intensive care units. For these reasons, kidney transplantation was suspended in France during the first epidemic wave. Here, we retrospectively evaluated this strategy by comparing the overall and COVID-19 related mortality in kidney transplant recipients and candidates over the last three years. Cross-interrogation of two national registries for the period 1 March and 1 June 2020, identified 275 deaths among the 42812 kidney transplant recipients and 144 deaths among the 16210 candidates. This represents an excess of deaths for both populations, as compared with the same period the two previous years (mean of two previous years: 253 in recipients and 112 in candidates). This difference was integrally explained by COVID-19, which accounted for 44% (122) and 42% (60) of the deaths in recipients and candidates, respectively. Taking into account the size of the two populations and the geographical heterogeneity of virus circulation, we found that the excess of risk of death due to COVID-19 was similar for recipients and candidates in high viral risk area but four-fold higher for candidates in the low viral risk area. Thus, in case of a second epidemic wave, kidney transplantation should be suspended in high viral risk areas but maintained outside those areas, both to reduce the excess of deaths of candidates and avoid wasting precious resources.


Asunto(s)
COVID-19/mortalidad , Epidemias/estadística & datos numéricos , Trasplante de Riñón/mortalidad , Complicaciones Posoperatorias/mortalidad , Sistema de Registros , Listas de Espera/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/virología , Estudios Retrospectivos
4.
Br J Sports Med ; 2020 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-33144349

RESUMEN

Elite athletes are particularly susceptible to sleep inadequacies, characterised by habitual short sleep (<7 hours/night) and poor sleep quality (eg, sleep fragmentation). Athletic performance is reduced by a night or more without sleep, but the influence on performance of partial sleep restriction over 1-3 nights, a more real-world scenario, remains unclear. Studies investigating sleep in athletes often suffer from inadequate experimental control, a lack of females and questions concerning the validity of the chosen sleep assessment tools. Research only scratches the surface on how sleep influences athlete health. Studies in the wider population show that habitually sleeping <7 hours/night increases susceptibility to respiratory infection. Fortunately, much is known about the salient risk factors for sleep inadequacy in athletes, enabling targeted interventions. For example, athlete sleep is influenced by sport-specific factors (relating to training, travel and competition) and non-sport factors (eg, female gender, stress and anxiety). This expert consensus culminates with a sleep toolbox for practitioners (eg, covering sleep education and screening) to mitigate these risk factors and optimise athlete sleep. A one-size-fits-all approach to athlete sleep recommendations (eg, 7-9 hours/night) is unlikely ideal for health and performance. We recommend an individualised approach that should consider the athlete's perceived sleep needs. Research is needed into the benefits of napping and sleep extension (eg, banking sleep).

5.
J Strength Cond Res ; 34(12): 3554-3559, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28902109

RESUMEN

Granier, C, Hausswirth, C, Dorel, S, and Le Meur, Y. Validity and reliability of the stages cycling power meter. J Strength Cond Res 34(12): 3554-3559, 2020-This study aimed to determine the validity and the reliability of the Stages power meter crank system (Boulder, United States) during several laboratory cycling tasks. Eleven trained subjects completed laboratory cycling trials on an indoor cycle fitted with SRM Professional and Stages systems. The trials consisted of an incremental test at 100 W, 200 W, 300 W, 400 W, and four 7-s sprints. The level of pedaling asymmetry was determined for each cycling intensity during a similar protocol completed on a Lode Excalibur Sport ergometer. The reliability of Stages and SRM power meters was compared by repeating the incremental test during a test-retest protocol on a Cyclus 2 ergometer. Over power ranges of 100-1,250 W, the Stages system produced trivial to small differences compared with the SRM (standardized typical error values of 0.06, 0.24, and 0.08 for the incremental, sprint, and combined trials, respectively). A large correlation was reported between the difference in power output (PO) between the 2 systems and the level of pedaling asymmetry (r = 0.58, p < 0.001). Recalculating PO of the Stages system according to the level of pedaling asymmetry provided only marginal improvements in PO measures. The reliability of the Stages power meter at the submaximal intensities was similar to the SRM Professional model (coefficient of variation: 2.1 and 1.3% for Stages and SRM, respectively). The Stages system is a suitable device for PO measurements, except when a typical error of measurement <3.0% over power ranges of 100-1,250 W is expected.


Asunto(s)
Prueba de Esfuerzo , Deportes , Ciclismo , Ergometría , Reproducibilidad de los Resultados
6.
Kidney Int ; 95(6): 1471-1485, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30955869

RESUMEN

Human leukocyte antigen (HLA) mismatching and minimization of immunosuppression are two major risk factors for the development of de novo donor-specific antibodies, which are associated with reduced kidney graft survival. Antibodies do not recognize whole HLA antigens but rather individual epitopes, which are short sequences of amino acids in accessible positions. However, compatibility is still assessed by the simple count of mismatched HLA antigens. We hypothesized that the number of mismatched epitopes, or ("epitope load") would identify patients at the highest risk of developing donor specific antibodies following minimization of immunosuppression. We determined epitope load in 89 clinical trial participants who converted from cyclosporine to everolimus 3 months after kidney transplantation. Twenty-nine participants (32.6%) developed de novo donor specific antibodies. Compared to the number of HLA mismatches, epitope load was more strongly associated with the development of donor specific antibodies. Participants with an epitope load greater than 27 had a 12-fold relative risk of developing donor-specific antibodies compared to those with an epitope load below that threshold. Using that threshold, epitope load would have missed only one participant who subsequently developed donor specific antibodies, compared to 8 missed cases based on a 6-antigen mismatch. DQ7 was the most frequent antigenic target of donor specific antibodies in our population, and some DQ7 epitopes appeared to be more frequently involved than others. Assessing epitope load before minimizing immunosuppression may be a more efficient tool to identify patients at the highest risk of allosensitization.


Asunto(s)
Rechazo de Injerto/prevención & control , Antígenos HLA-DQ/sangre , Inmunosupresores/administración & dosificación , Isoantígenos/sangre , Trasplante de Riñón/efectos adversos , Selección de Paciente , Adulto , Ciclosporina/administración & dosificación , Ciclosporina/efectos adversos , Sustitución de Medicamentos , Epítopos/inmunología , Everolimus/administración & dosificación , Everolimus/efectos adversos , Femenino , Estudios de Seguimiento , Rechazo de Injerto/sangre , Rechazo de Injerto/inmunología , Supervivencia de Injerto/inmunología , Antígenos HLA-DQ/inmunología , Prueba de Histocompatibilidad , Humanos , Inmunosupresores/efectos adversos , Isoantígenos/inmunología , Masculino , Persona de Mediana Edad , Trasplante Homólogo/efectos adversos
7.
Transpl Int ; 27(4): 344-52, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24279707

RESUMEN

In this ancillary study of the CONCEPT trial, we studied the role of CsA withdrawal at 3 months (3M) post-transplant on the intensity of epithelial phenotypic changes (EPC, an early marker for kidney fibrogenesis) on the 12 M surveillance biopsy. Although conversion from CsA to sirolimus (SRL) at 3M was reported to have improved mean graft function at 12 M, it did not reduce the score of EPC (1.73 ± 1.15 in the SRL group vs. 1.87 ± 1 in the CsA group, P = 0.61). Acute rejection, which had occurred twice more frequently in SRL-converted patients included here, was associated with 12 M EPC. Interestingly, we observed that the patients durably exposed to CsA and who developed 12 M EPC had a significant progression of blood pulse pressure (pp) from 1 to 6M post-transplantation (Δpp = +12.3 mmHg, P = 0.0035). Pulse pressure at 4, 6, and 9 M and pp progression from 1 to 6M were significantly associated with the development of EPC at 12 M in renal grafts. Logistic regression analysis revealed that a high 6M pp (≥ 60 mmHg) was an independent risk factor for 12 M EPC with an odds ratio of 2.25 per additional 10 mmHg pp (95%CI: 1.14-4.4, P = 0.02) after adjustment with recipient's and donor's age, acute rejection incidence and immunosuppressive regimen. A post hoc analysis of the data collected in the whole population CONCEPT study revealed that pp was significantly higher at 6 months in patients maintained on CsA and that at this time point pp correlated negatively with GFR at 1 year.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Ciclosporina/efectos adversos , Inmunosupresores/efectos adversos , Trasplante de Riñón/efectos adversos , Adulto , Inhibidores de la Calcineurina , Ciclosporina/administración & dosificación , Epitelio/efectos de los fármacos , Epitelio/patología , Femenino , Fibrosis , Tasa de Filtración Glomerular/efectos de los fármacos , Rechazo de Injerto , Humanos , Inmunosupresores/administración & dosificación , Riñón/efectos de los fármacos , Riñón/patología , Riñón/fisiopatología , Masculino , Persona de Mediana Edad , Fenotipo , Factores de Riesgo , Sirolimus/administración & dosificación , Factores de Tiempo
8.
BMC Nephrol ; 15: 138, 2014 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-25163389

RESUMEN

BACKGROUND: Genetic factors are suspected in the pathogenesis of IgA nephropathy, as well as in the course of IgA nephropathy progression towards end stage renal failure. UMOD polymorphism rs12917707 is known to associate with end stage renal failure of mixed aetiologies. METHODS: We tested a large cohort of Caucasian patients for association of rs12917707 with IgA nephropathy showing a benign, stable course and with IgA nephropathy that progressed toward end stage renal failure. RESULTS: No association was observed between either groups, and a non-significant trend was observed for more severe IgA nephropathy with the allele reported to protect against end stage renal failure of mixed aetiologies. CONCLUSION: We conclude that UMOD is unlikely to play a role in IgA nephropathy pathogenesis nor progression to end stage renal failure, and suggest that UMOD effects are restricted to some causes of renal disease, e.g. diabetes or hypertension.


Asunto(s)
Estudios de Asociación Genética/métodos , Glomerulonefritis por IGA/genética , Polimorfismo Genético/genética , Índice de Severidad de la Enfermedad , Uromodulina/genética , Población Blanca/genética , Adulto , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Glomerulonefritis por IGA/diagnóstico , Glomerulonefritis por IGA/epidemiología , Humanos , Masculino , Persona de Mediana Edad
9.
Med Mycol ; 51(8): 851-62, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23964829

RESUMEN

Pneumocystis jirovecii, a transmissible fungus, is the causative agent of pulmonary infections. Its genomic diversity has appeared in reports from around the world but data on P. jirovecii genotypes in France are still limited. This study describes the typing of P. jirovecii isolates from 81 HIV-negative patients monitored at Brest University Hospital, Brittany, France, 40 of whom developed Pneumocystis pneumonia (PcP), and remaining 41 patients were colonized by the fungus. The isolates were assayed at the internal transcribed spacer (ITS)1 and ITS2 under improved amplification conditions to avoid in vitro ITS recombination. P. jirovecii ITS haplotypes were identified in 56/81 patients (31 PcP patients and 25 patients who were colonized) which revealed a high diversity in that 27 different haplotypes were identified. Eg was the most frequent haplotype (31/56, 55.3%), followed by Ec and Ai (5/56, 8.9% each). In contrast, Ne, usually the second most frequent haplotype in Europe and the USA, was observed in only 2/56 patients (3.6%). Mixed infections were detected in 18/56 patients (32.1%; 12 PcP patients and six who were colonized). No significant differences were observed in haplotype diversity, frequency of peculiar haplotypes, and mixed infection occurrence, between the two patient populations. The study, conducted with the largest HIV-negative patient population investigated so far, shows that ITS typing remains an efficient method for characterizing P. jirovecii among human populations, whatever their clinical presentation of Pneumocystis infections.


Asunto(s)
ADN Espaciador Ribosómico/genética , Variación Genética , Haplotipos , Infecciones por Pneumocystis/microbiología , Pneumocystis carinii/clasificación , Pneumocystis carinii/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Infecciones por Pneumocystis/epidemiología , Pneumocystis carinii/aislamiento & purificación , Adulto Joven
10.
Hum Mutat ; 33(8): 1239-50, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22508176

RESUMEN

Autosomal dominant polycystic kidney disease (ADPKD), the most common inherited kidney disorder, is caused by mutations in PKD1 or PKD2. The molecular diagnosis of ADPKD is complicated by extensive allelic heterogeneity and particularly by the presence of six highly homologous sequences of PKD1 exons 1-33. Here, we screened PKD1 and PKD2 for both conventional mutations and gross genomic rearrangements in up to 700 unrelated ADPKD patients--the largest patient cohort to date--by means of direct sequencing, followed by quantitative fluorescent multiplex polymerase chain reaction or array-comparative genomic hybridization. This resulted in the identification of the largest number of new pathogenic mutations (n = 351) in a single publication, expanded the spectrum of known ADPKD pathogenic mutations by 41.8% for PKD1 and by 23.8% for PKD2, and provided new insights into several issues, such as the population-dependent distribution of recurrent mutations compared with founder mutations and the relative paucity of pathogenic missense mutations in the PKD2 gene. Our study, together with others, highlights the importance of developing novel approaches for both mutation detection and functional validation of nondefinite pathogenic mutations to increase the diagnostic value of molecular testing for ADPKD.


Asunto(s)
Análisis Mutacional de ADN/métodos , Riñón Poliquístico Autosómico Dominante/genética , Canales Catiónicos TRPP/genética , Hibridación Genómica Comparativa , Femenino , Humanos , Reacción en Cadena de la Polimerasa Multiplex , Mutación/genética , Mutación Missense/genética
11.
Clin Infect Dis ; 54(7): e62-71, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22337822

RESUMEN

BACKGROUND: Eighteen renal transplant recipients (RTRs) developed Pneumocystis jirovecii infections at the renal transplantation unit of Brest University Hospital (Brest, Brittany, France) from May 2008 through April 2010, whereas no cases of P. jirovecii infection had been diagnosed in this unit since 2002. This outbreak was investigated by identifying P. jirovecii types and analyzing patient encounters. METHODS: The identification of P. jirovecii internal transcribed spacer (ITS) types was performed on P. jirovecii isolates from the 18 RTRs (12 patients with Pneumocystis pneumonia [PCP], 6 colonized patients), 22 unlinked control patients (18 patients with PCP, 4 colonized patients), and 69 patients (34 patients with PCP, 35 colonized patients) with contemporaneously diagnosed P. jirovecii infections in the Brest geographic area. A transmission map was drawn up. Its analysis was combined with the results of P. jirovecii typing. RESULTS: P. jirovecii ITS type identification was successful in 14 of 18 RTRs, 15 of 22 control patients, and 48 of the 69 patients. Type Eg was the most frequent type in the 3 patient groups. However, its frequency was significantly higher in the first patient group than in the 2 other groups (P < .05 and P < .01, respectively). Fourteen encounters between RTRs who harbored an identical type were observed. Ten patients were considered as possible index patients, of whom 3 were colonized by the fungus, and 7 presented PCP. CONCLUSIONS: The results provide to our knowledge the first data on the role of colonized patients as potential sources of P. jirovecii in a context of nosocomial acquisition of the fungus.


Asunto(s)
Brotes de Enfermedades , Trasplante de Riñón/efectos adversos , Tipificación Molecular , Técnicas de Tipificación Micológica , Infecciones por Pneumocystis/epidemiología , Pneumocystis carinii/clasificación , Pneumocystis carinii/aislamiento & purificación , Adulto , Anciano , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Femenino , Francia/epidemiología , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Infecciones por Pneumocystis/microbiología , Pneumocystis carinii/genética , Trasplante
12.
Eur J Appl Physiol ; 112(7): 2583-93, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22081048

RESUMEN

To evaluate the physiological demands and effects of different pacing strategies on performance during the new combined event (CE) of the modern pentathlon (consisting of three pistol shooting sessions interspersed by three 1-km running legs). Nine elite pentathletes realised five tests: a free-paced CE during an international competition; an incremental running test to determine [Formula: see text] and its related velocity ([Formula: see text]) and three experimental time-trial CE, where the pacing strategy was manipulated (CE(ref), CE(100%), CE(105%)). CE(ref) reproduced the international competition strategy with a 170-m fast running start within the first 2 km. CE(100%) and CE(105%) imposed a constant strategy over km-1 and km-2 with a velocity of 100 and 105% of the mean speed adopted over the same sections during the international competition, respectively. Km-3 was always self-paced. The subjects ran CE(ref) at 99 ± 4% of [Formula: see text] and reached 100 ± 5, 100 ± 7, 99 ± 8% of [Formula: see text] at the end of kilometres 1, 2 and 3, respectively ([Formula: see text]: 72 ± 6 mL O(2) min(-1) kg(-1)), with a peak blood lactate concentration of 13.6 ± 1.5 mmol L(-1). No significant differences in overall performance were found between the pacing conditions (753 ± 30, 770 ± 39, 768 ± 27 s for CE(ref), CE(100%) and CE(105%), respectively, p = 0.63), but all of the shooting performance parameters were only stable in CE(ref). Completion of CE by elite pentathletes elicits a maximal aerobic contribution coupled with a high glycolytic supply. Manipulating the mean running speed over km-1 and km-2 had strong influence on the overall pacing strategy and induced minor differences in shooting performance, but it did not affect overall performance.


Asunto(s)
Rendimiento Atlético/fisiología , Ácido Láctico/sangre , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Esfuerzo Físico/fisiología , Carrera/fisiología , Femenino , Humanos , Masculino , Adulto Joven
13.
Br J Clin Pharmacol ; 69(6): 675-83, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20565459

RESUMEN

AIM: In renal transplant patients given mycophenolate mofetil (MMF), we investigated the relationship between the digestive adverse events and polymorphisms in the UGT genes involved in mycophenolic acid (MPA) intestinal metabolism and biliary excretion of its phase II metabolites. METHODS: Clinical data and DNA from 256 patients transplanted between 1996 and 2006 and given MMF with cyclosporin (CsA, n = 185), tacrolimus (TAC, n = 49) or sirolimus (SIR, n = 22), were retrospectively analysed. The relationships between diarrhoea and polymorphisms in UGT1A8 (2; 518C>G, 3; 830G>A), UGT1A7 (622C>T), UGT1A9 (-275T>A), UGT2B7 (-840G>A) and ABCC2 (-24C>T, 3972C>T) or the co-administered immunosuppressant were investigated using the Cox proportional hazard model. RESULTS: Multivariate analysis showed that patients on TAC or SIR had a 2.8 higher risk of diarrhoea than patients on CsA (HR = 2.809; 95%CI (1.730, 4.545); P < 0.0001) and that non-carriers of the UGT1A8 2 allele (CC518 genotype) had a higher risk of diarrhoea than carriers (C518G and 518GG genotypes) (HR = 1.876; 95%CI (1.109, 3.175); P = 0.0192). When patients were divided according to the immunosuppressive co-treatment, a significant effect of UGT1A8 2 was found in those co-treated with CsA (HR = 2.414; 95%CI (1.089, 5.354); P = 0.0301) but not TAC or SIR (P = 0.4331). CONCLUSION: These results suggest that a possible inhibition of biliary excretion of MPA metabolites by CsA and a decreased intestinal production of these metabolites in UGT1A8 2 carriers may be protective factors against MMF-induced diarrhoea.


Asunto(s)
Diarrea/inducido químicamente , Diarrea/genética , Glucuronosiltransferasa/genética , Inmunosupresores/efectos adversos , Trasplante de Riñón , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/metabolismo , Polimorfismo de Nucleótido Simple/fisiología , Adulto , Estudios de Cohortes , Ciclosporina/administración & dosificación , Combinación de Medicamentos , Interacciones Farmacológicas , Femenino , Genotipo , Humanos , Inmunosupresores/uso terapéutico , Trasplante de Riñón/mortalidad , Masculino , Proteína 2 Asociada a Resistencia a Múltiples Medicamentos , Análisis Multivariante , Ácido Micofenólico/efectos adversos , Ácido Micofenólico/uso terapéutico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Riesgo , Sirolimus/administración & dosificación , Análisis de Supervivencia , Tacrolimus/administración & dosificación
14.
Eur J Appl Physiol ; 108(6): 1115-23, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20024576

RESUMEN

The aim of the present study was to determine the best pacing strategy to adopt during the initial phase of a short distance triathlon run for highly trained triathletes. Ten highly trained male triathletes completed an incremental running test to determine maximal oxygen uptake, a 10-km control run at free pace and three individual time-trial triathlons (1.5-km swimming, 40-km cycling, 10-km running) in a randomised order. Swimming and cycling speeds were imposed as identical to the first triathlon performed and the first run kilometre was done alternatively 5% faster (Tri-Run(+5%)), 5% slower (Tri-Run(-5%)) and 10% slower (Tri-Run(-10%)) than the control run (C-Run). The subjects were instructed to finish the 9 remaining kilometres as quickly as possible at a free self-pace. Tri-Run(-5%) resulted in a significantly faster overall 10-km performance than Tri-Run(+5%) and Tri-Run(-10%) (p < 0.05) but no significant difference was observed with C-Run (p > 0.05) (2,028 +/- 78 s vs. 2,000 +/- 72 s, 2,178 +/- 121 s and 2,087 +/- 88 s, for Tri-Run(-5%), C-Run, Tri-Run(+5%) and Tri-Run(-10%), respectively). Tri-Run(+5%) strategy elicited higher values for oxygen uptake, ventilation, heart rate and blood lactate at the end of the first kilometre than the three other conditions. After 5 and 9.5 km, these values were higher for Tri-Run(-5%) (p < 0.05). The present results showed that the running speed achieved during the cycle-to-run transition is crucial for the improvement of the running phase as a whole. Triathletes would benefit to automate a pace 5% slower than their 10-km control running speed as both 5% faster and 10% slower running speeds over the first kilometre involved weaker overall performances.


Asunto(s)
Esfuerzo Físico/fisiología , Carrera/fisiología , Análisis y Desempeño de Tareas , Adulto , Humanos , Masculino
15.
J Sports Sci ; 28(10): 1111-6, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20686991

RESUMEN

The aims of this study were to determine (1) the individual tactics employed by elite modern pentathletes within each discipline of the new combined running-shooting event, and (2) the consequences of these strategies on overall performance. For 36 male pentathletes competing in a World Cup event, we measured running velocity, transition time, shooting time, shooting accuracy, and delay per shot. Performances of the top third of athletes, middle third of athletes, and the bottom third of athletes in the combined event were compared. The difference in overall performance between the top third and middle/bottom thirds was predominately associated with better shooting accuracy (79 +/- 13%, 68 +/- 12%, and 64 +/- 10% success rate for top, middle, and bottom third, respectively) and faster shooting time (86 +/- 16 s, 109 +/- 19 s, and 117 +/- 23 s for top, middle, and bottom third, respectively). No significant differences in running velocity, transition time or delay per shot were observed among the three groups. All the competitors started significantly faster over the first 200 m of each of the three 1-km running stages. The last third of the approximately 3-km race was completed significantly faster by all athletes (P < 0.05). The main finding was that the best performers of the combined event distinguished themselves due to their greater shooting accuracy.


Asunto(s)
Atletas , Rendimiento Atlético/fisiología , Carrera/fisiología , Armas de Fuego , Humanos , Masculino , Análisis y Desempeño de Tareas
16.
Eur J Appl Physiol ; 106(4): 535-45, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19340453

RESUMEN

The aim of this study was to compare the pacing strategies adopted by women and men during a World Cup ITU triathlon. Twelve elite triathletes (6 females, 6 males) competed in a World Cup Olympic distance competition where speed and heart rate (HR) were measured in the three events. The power output (PO) was recorded in cycling to determine the time spent in five intensity zones ([0-10% VT1]; [10% VT1-VT1]; [VT1-VT2]; [VT2-MAP] and > or =MAP) [ventilatory threshold (VT); maximal aerobic power (MAP)]. Swimming and running speeds decreased similarly for both genders (P < 0.05) and HR values were similar through the whole race (92 +/- 2 and 92 +/- 3% of maximal HR for women and men, respectively). The distribution of time spent in the five zones during the cycling leg was the same for both genders. The men's speed and PO decreased after the first bike lap (P < 0.05) and the women spent relatively more time above MAP in the hilly sections (45 +/- 4 vs. 32 +/- 4%). The men's running speed decreased significantly over the whole circuit, whereas the women slowed only over the uphill and downhill sections (P < 0.05). This study indicates that both female and male elite triathletes adopted similar positive pacing strategies during swimming and running legs. Men pushed the pace harder during the swim-to-cycle transition contrary to the women and female triathletes were more affected by changes in slope during the cycling and running phases.


Asunto(s)
Ciclismo/fisiología , Esfuerzo Físico/fisiología , Carrera/fisiología , Natación/fisiología , Análisis y Desempeño de Tareas , Adulto , Femenino , Humanos , Masculino , Factores Sexuales
17.
Curr Biol ; 29(19): 3289-3297.e4, 2019 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-31564497

RESUMEN

Overtraining syndrome is a form of burnout, defined in endurance athletes by unexplained performance drop associated with intense fatigue sensation. Our working hypothesis is that the form of fatigue resulting from physical training overload might share some neural underpinnings with the form of fatigue observed after prolonged intellectual work, which was previously shown to affect the cognitive control brain system. Indeed, cognitive control may be required to prevent any impulsive behavior, including stopping physical effort when it hurts, despite the long-term goal of improving performance through intense training. To test this hypothesis, we induced a mild form of overtraining in a group of endurance athletes, which we compared to a group of normally trained athletes on behavioral tasks performed during fMRI scanning. At the behavioral level, training overload enhanced impulsivity in economic choice, which was captured by a bias favoring immediate over delayed rewards in our computational model. At the neural level, training overload resulted in diminished activation of the lateral prefrontal cortex, a key region of the cognitive control system, during economic choice. Our results therefore provide causal evidence for a functional link between enduring physical exercise and exerting cognitive control. Besides, the concept of cognitive control fatigue bridges the functional consequences of excessive physical training and intellectual work into a single neuro-computational mechanism, which might contribute to other clinical forms of burnout syndromes.


Asunto(s)
Atletas/psicología , Cognición , Análisis Costo-Beneficio , Toma de Decisiones , Fatiga/psicología , Conducta Impulsiva , Acondicionamiento Físico Humano/efectos adversos , Adulto , Humanos , Masculino , Acondicionamiento Físico Humano/psicología
18.
Ann Transplant ; 24: 517-526, 2019 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-31477681

RESUMEN

BACKGROUND Potential benefits of once-daily, prolonged-release tacrolimus over the immediate-release formulation include improved adherence to immunosuppressives post transplantation. An observational study was performed to characterize real-world practice surrounding conversion from immediate- to prolonged-release tacrolimus in kidney transplant recipients. MATERIAL AND METHODS We performed a prospective, observational study of renal transplant recipients converted from immediate- to prolonged-release tacrolimus capsules. Conversion took place at the baseline visit, within the first 6 months of transplantation (early conversion group) or between 6 and 12 months of transplantation (late conversion group). Data collection was performed at routine follow-up at 6 and 12 months. Endpoints included conversion ratio from immediate- to prolonged-release tacrolimus, reasons for conversion, additional visits due to conversion, safety, and tolerability. RESULTS The analysis population comprised 591 patients. Baseline characteristics were similar between the 2 groups. The mean conversion ratio of the daily dose of tacrolimus was 0.98±0.17 in the early group and 0.99±0.09 in the late group. Time from conversion (mean ±SD) to first measurement of trough tacrolimus blood concentration was 12.1±11.6 and 27.6±26.7 days in the early and late groups, respectively. The highest number of additional visits required was 6 in the early conversion group, in 3 patients (0.7%), and 3 in the late conversion group, in 2 patients (1.6%). Conversion from immediate- to prolonged-release tacrolimus was associated with a very low rate of graft rejection. CONCLUSIONS Favorable clinical outcomes and safety profiles were observed with conversion from immediate- to prolonged-release tacrolimus over 1 year following renal transplantation, with no marked differences between the early and late conversion groups.


Asunto(s)
Preparaciones de Acción Retardada/administración & dosificación , Inmunosupresores/administración & dosificación , Trasplante de Riñón , Tacrolimus/administración & dosificación , Adulto , Anciano , Preparaciones de Acción Retardada/uso terapéutico , Esquema de Medicación , Femenino , Francia , Humanos , Inmunosupresores/uso terapéutico , Masculino , Cumplimiento de la Medicación , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Tacrolimus/uso terapéutico , Receptores de Trasplantes , Resultado del Tratamiento
19.
Artículo en Inglés | MEDLINE | ID: mdl-33344995

RESUMEN

The objective of this manuscript was to examine the periodization strategy of an international Rugby-7s team during an Olympic season. Training load data were collected in 14 elite male players over a 48-week period during the 2015-2016 Olympic season. The season consisted of 3 macrocycles including: preseason (12-weak duration), in-season (25-weak) fragmented into four 4-7 weeks mesocycles (In-1-4) and the final preparation for the Rio 2016 Olympic Games (Olympic preparation, 11-weak). External training load (TL) such as the total distance (TD), the high-intensity distance (HID) and the number of accelerations performed, was monitored in training and competition over the entire duration of the season using a global positioning system (GPS) devices. The rating of perceived exertion (RPE) was multiplied by the session duration (min) to provide an internal TL (session-RPE) value for all training sessions and competitions. The Olympic preparation may enable planning of higher external TL compared to the preseason (TD, 21 ± 13%, moderate; total accelerations, 27 ± 4%, moderate) whereas no difference was observed for internal TL values between these two periods. High-intensity distance (HID) and internal TL (session-RPE) were lower (-11.0 ± 7.8%, small and -38 ± 3%, moderate, respectively) during the in-season compared to preseason. Internal TL, TD as well as HID were lower in the third in-season mesocycle (In-3) compared with the first in-season mesocycle (In-1) (-25 ± 12%, moderate; -32 ± 4%, moderate; -49 ± 8%, moderate, respectively). The staff managed the workload considering the in-season as the main part of the "Road to Rio." The strategy to reduce the workload at the middle of the season and to induce weeks of regeneration at the end of the in-season was highlighted by the training availability of 100% of the squad at the beginning of the Olympic preparation. The workload periodization strategy of an Olympic season differs from the strategy previously described during a non-Olympic season.

20.
Int J Sports Physiol Perform ; 14(1): 113-121, 2019 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-29952634

RESUMEN

PURPOSE: To describe the training periodization in rugby sevens players competing in the World Rugby Sevens Series during a non-Olympic season. METHODS: Workload data were collected over a 33-wk period in 12 male players participating in a full competitive season. Workload was quantified using session rating of perceived exertion and global positioning system-derived data during training and competition. Self-reported well-being was assessed using a questionnaire. Each variable was analyzed weekly and through 5 mesocycles (preseason, in-season 1-4), each of which ended with competition blocks. RESULTS: The perceived load decreased throughout the season for the full squad (-68% [26%] between preseason and final competitive block, large effect) and when unavailable players were removed from the analysis (-38% [42%], moderate). Weekly perceived load was highly variable, with a typical periodization in 4 phases during each mesocycle (regeneration, training overload, taper, and competition). During the preseason, the workload was higher during the overload training phase than during the competitive period (range: +23% to +59%, large to very large, for the distance covered above individual maximal aerobic speed and the number of accelerations). This observation no longer persisted during the season. The well-being score decreased almost certainly from in-season 3 (moderate). CONCLUSIONS: These results highlighted the apparent difficulty in maintaining high-load training periods throughout the season in players engaged on the World Rugby Sevens Series despite ∼4-7 training weeks separating each competitive block. This observation was likely explained by the difficulties inherent to the World Rugby Sevens Series (risk of contact injury, calendar, and multiple long-haul travel episodes) and potentially by limited squad-rotation policies.

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