[The effect of corifollitropin alfa on in vitro fertilization-ICSI patients with previous failure with an FSH/HMG protocol: Preliminary report in Mexico]. / Efecto de la corifolitropina alfa en pacientes de fertilización in vitro-ICSI con falla previa en un protocolo de FSH/HMG: experiencia preliminar en México.

BACKGROUND: The daily application of drugs, often in high doses, is a factor of stress for the infertile couple. During the last decade corifollitropin alpha has allowed a friendlier scheme comparable to traditional protocols (rFSH-HMG) results. OBJECTIVE: To compare the results of corifollitropin alpha in patients with a previous cycle of IVF-ICSI with traditional scheme ovarian stimulation. MATERIALS AND METHODS: Observational, retrospective cohort study type that infertile couples were included. RESULTS: No significant differences in the dose used HFRS (2023U/ total ± 712 vs 636 U/total ± 307) and serum estradiol day shooting HGCr (1972 pg/dL vs 1107 ± 1152 pg/dL ± 775). A higher pregnancy rate was found corifollitropin alpha perhaps because it was a second attempt at in vitro fertilization. CONCLUSIONS: Reproductive outcomes in a cycle of ovarian stimulation with corifollitropin are comparable with the results of a traditional ovarian stimulation cycle. It is important to broaden the experience of the drug indication in Mexican patients.

Effect of cycling competition type on effort based on heart rate and session rating of perceived exertion.

AIM: The aim of this study was to compare the exercise intensity and competition load during Time Trial (TT), Flat (FL), Medium Mountain (MM) and High Mountain (HM) stages based heart rate (HR) and session rating of perceived exertion (RPE). METHODS: We monitored both HR and RPE of 12 professional cyclists during two consecutive 21-day cycling races (Vuelta a España) in order to analyze the exercise intensity and competition load (TRIMPHR and TRIMPRPE). RESULTS: The highest (P<0.05) mean HR was found in TT (169±2 bpm) versus those observed in FL (135±1 bpm), MM (139±3 bpm), HM (143±1 bpm). However, higher (P<0.05) session RPE were found in HM (7.3±0.2) and MM (7.0±0.3) vs. TT (5.5±0.4) and FL (4.6±0.2). TRIMPHR and TRIMPRPE increased significantly (P<0.05) in the following order: TT, FL, MM and HM. The greatest (P<0.05) TRIMPHR·km-1 and TRIMPRPE·km-1 were obtained in TT (~4 units) and HM (~12 units), respectively. We found significant (p<0.001) correlations between TRIMPHR and TRIMPRPE in TT (r=0.62), FL (r=0.74), MM (r=0.89) and HM (r=0.78). CONCLUSION: In conclusion, professional cycling is a highly demanding sport which exercise intensity and competition load varied according to the type of stages. The session RPE method is a valid estimate of internal load during different cycling stage categories.

Physical and thermal strain of firefighters according to the firefighting tactics used to suppress wildfires.

The aim of this study was to analyse the physiological strain of firefighters, using heart rate (HR) and core temperature, during real wildfire suppression according to the type of attack performed (direct, indirect or mixed). Three intensity zones were established according to the HR corresponding to the ventilatory threshold (VT) and respiratory compensation threshold (RCT): zone 1, RCT. The exercise workload (training impulse (TRIMP)), the physiological strain index (PSI) and the cumulative heat strain index(CHSI) were calculated using the time spent in each zone, and the HR and core temperature, respectively. Significantly higher mean HR, time spent in Z2 and Z3 and TRIMP h(-1) were found in direct and mixed versus indirect attacks. The highest PSI and CHSI were observed in the direct attack. In conclusion, exercise strain and combined thermal strain, but not core temperature during wildfire suppression, are related to the type of attack performed. STATEMENT OF RELEVANCE: Our findings demonstrated that wildfire firefighting is associated with high physiological demands, which vary significantly depending on the tactics chosen for performing the task. These results should be kept in mind when planning programmes to improve wildland firefighters' physical fitness, which will allow improvement in their performance.

Workload demands in professional multi-stage cycling races of varying duration.

OBJECTIVE: To analyse and compare the workload exerted by professional cyclists in 5-day, 8-day and 21-day stage races (5-SR, 8-SR, 21-SR). METHODS: The study subjects were 30 professional cyclists competing in 10 5-SR, 5 8-SR and 5 21-SR. Heart rate (HR) was measured during the races and categorised into three intensity zones: Z1 (below the ventilatory threshold (VT)), Z2 (between VT and the respiratory compensation threshold (RCT)) and Z3 (above RCT). The training impulse (TRIMP) was calculated by multiplying the sum of the time spent in each zone by 1, 2 and 3, respectively. Monotony (average TRIMP/SD) and strain (total TRIMPxmonotony) were also calculated for each race type. RESULTS: The average time spent in Z3 during each stage was significantly (p<0.05) higher for 5-SR ( approximately 31 min) and 8-SR ( approximately 28 min) than for 21-SR ( approximately 14 min). Daily TRIMP values in 5-SR ( approximately 400) and 8-SR ( approximately 395) were also higher than in 21-SR ( approximately 370). Monotony was similar across races ( approximately 3) but strain was about three times higher for 21-SR than for 5-SR and 8-SR. CONCLUSIONS: The cyclists' effort by stage was less for 21-SR than for 5-SR and 8-SR. Competition strain and monotony accumulated during longer races influence the choice of strategies adopted by cyclists. It is likely that the intensity of each stage is modulated by total race duration, with longer races averaging the lowest daily workload.

Changes in the biliary excretion of organic anions following exhaustive exercise in rats.

The effect of exhaustive exercise on the hepatobiliary transport of organic anions was investigated in rats. Animals were run on a rodent treadmill at 24 m/min up a 12% grade (152 +/- 15 min). Exercise resulted in significant hypoglycaemia (-46%) and increased plasma levels of lactate (+12%), together with a marked reduction of glycogen concentration in the liver (-72%). When bromosulphthalein was administered i.v., its maximal biliary excretion (Tm) was significantly reduced (-30%), and plasma and liver concentrations of the dye were increased (+31% and +56%, respectively). The decrease corresponded both to the excretion of the conjugated and unconjugated dye (-30% and -33%, respectively). Cytosolic glutathione S-transferase activity in the liver was not affected by exercise, but there was a significant reduction in the hepatic concentration of glutathione (-50%). The Tm of dibromosulphthalein was also significantly reduced (-36%) and its plasma and liver concentrations increased (+67% and +33%, respectively) in exercised rats. The results suggest that, in addition to the direct effect of liver glutathione depletion, other factors must be involved in the impairment of the biliary excretion of organic anions caused by exercise.

Effects of long-distance running on serum bilirubin.

This study was undertaken to determine the effects of long-distance running on serum bilirubin fractions. Thirteen male ultramarathon runners participating in a 100-km race volunteered for the study. Venous blood samples were obtained shortly before and immediately after the race. Decreased serum haptoglobin levels (-66%) indicated the presence of hemolysis. After accounting for plasma-volume loss, significant post-race increases were found for creatine kinase (+20-fold), creatine kinase-MB (+252%), alanine aminotransferase (+42%), aspartate aminotransferase (+193%), gammaglutamyl transpeptidase (+56%), and glutamate dehydrogenase (+58%) serum activities, suggesting that running causes alterations of both muscle and liver tissues. Serum concentration of total bilirubin was significantly elevated (+106%) following the race, with changes corresponding to both unconjugated (+96%) and conjugated esters (+283%) of the pigment and significant increases in the ratio of esterified to total bilirubin. Our data show that long-distance running causes increases in the different serum bilirubin fractions which can be accounted for both hemolysis and hepatic disturbances.

Effects of oral contraceptives on fibrinolytic response to exercise.

In this study the influence of low-dose oral contraceptives (OC) on the different components of the fibrinolytic system before and immediately after maximal exercise was examined in a group of 18 moderately active women. Nine women using OC and nine control women performed a maximal effort treadmill protocol. Comparison of the resting parameters revealed higher plasma FbDP, plasminogen, alpha 2-antiplasmin and protein C concentrations, and lower PAI activity in the OC group. No differences were observed in plasma concentrations of t-PA antigen, t-PA activity, PAI antigen, antithrombin III, and protein S. Acute maximal exercise resulted in significant increases in t-PA antigen, t-PA activity, t-PA/PAI complexes, and FbDP in both groups of subjects, while PAI activity was reduced. No significant differences were found for the change in those parameters between control and OC users. Exercise induced no variation in any of the groups for PAI antigen, alpha 2-antiplasmin, plasminogen, protein C, or protein S. Our data suggest that changes in the fibrinolytic system induced by physical exercise are not affected by oral contraceptives.

Mutations in the hereditary haemochromatosis gene HFE in professional endurance athletes.

BACKGROUND: Hereditary haemochromatosis, a disease that affects iron metabolism, progresses with a greater or lesser tendency to induce iron overload, possibly leading to severe organ dysfunction. Most elite endurance athletes take iron supplements during their active sporting life, which could aggravate this condition. OBJECTIVE: To determine the prevalence and discuss potential clinical implications of mutations of HFE (the gene responsible for hereditary haemochromatosis) in endurance athletes. METHODS: Basal concentrations of iron, ferritin, and transferrin and transferrin saturation were determined in the period before competition in 65 highly trained athletes. Possible mutations in the HFE gene were evaluated in each subject by extracting genomic DNA from peripheral blood. The restriction enzymes SnaBI and BclI were used to detect the mutations 845G-->A (C282Y) and 187C-->G (H63D). RESULTS: Our findings indicate a high prevalence of HFE gene mutations in this population (49.2%) compared with sedentary controls (33.5%). No association was detected in the athletes between mutations and blood iron markers. CONCLUSIONS: The findings support the need to assess regularly iron stores in elite endurance athletes.

Changes in metabolism and urinary excretion of antipyrine induced by aerobic conditioning.

BACKGROUND: Physical conditioning has been reported to increase liver oxidative metabolism determined by antipyrine clearance. The purpose of this investigation was to study effects of aerobic conditioning on the different metabolic pathways of antipyrine by comparing the production clearances of antipyrine metabolites. PARTICIPANT: volunteers not engaged in the systematic practice of any sport (n = 14) were compared with aerobically-conditioned subjects (n = 14) (long distance runners, defined as men running > 80 km/week). INTERVENTIONS: antipyrine was administered orally. Saliva samples were collected under basal conditions and at 8, 16, 24, 32 and 40 hrs following antipyrine administration. Urine was collected for 24 hrs after antipyrine ingestion. MEASURES: endurance performance was expressed by the maximal oxygen uptake (VO2max), the ventilatory threshold and the 4 mM.l-1 lactate threshold (OBLA). Antipyrine pharmacokinetic parameters (antipyrine clearance and half-live) were obtained from saliva samples by the standard multiple-sample method. RESULTS: VO2max, ventilatory threshold and OBLA were higher in trained than in control subjects (+32%, +16% and +74%, respectively). Salivary antipyrine clearance was higher, whether or not this variable was corrected for weight (+26% and +38%, respectively), and antipyrine half-life was significantly reduced (-31%) in runners. There was no significant change with training in the renal clearance of antipyrine or in the norantipyrine (NORA) formation clearance but significant increases were observed in hydroxymethylantipyrine (HMA) and 4-hydroxyantipyrine (OHA) formation clearances (+42 and +37%, respectively). CONCLUSIONS: The findings indicate that aerobic conditioning leads to increased disposition of antipyrine and that the main metabolic pathways of the compound are changed differently.

Effects of aerobic and anaerobic physical conditioning on fibrinolysis.

The effects of aerobic and anaerobic physical conditioning on fibrinolysis were studied before and immediately after physical exercise. Moderately active controls (group A) were compared with aerobically- (group B) or anaerobically-conditioned (group C) subjects. Comparison of the resting parameters revealed that FgDP were significantly higher in group B as a compared to groups A and C. FbDP did not significantly differ between groups B and C and were significantly lower in group A. t-PA antigen and PAI antigen did not significantly differ between the three groups, but t-PA activity was elevated and PAI activity and t-PA/PAI complexes were reduced in group B. Following a maximal exercise test on the treadmill both FbDP and FgDP were significantly increased in all groups, although values for FbDP in group B and values for FgDP in group C reached a higher level than in group A. t-PA antigen and t-PA activity were also increased in the three groups. PAI activity was significantly reduced in groups A and C. t-PA/PAI complexes were significantly enhanced in all cases, but increased to a lower degree in group B. These results indicate that both aerobic and anaerobic physical conditioning induce activation of the fibrinolytic system.