Effets d'une restriction hydrique et alimentaire prolongée (ramadan) sur la performance et les réponses cardiovasculaires au cours d'un exercice incrémental en milieu tropical chaud

Backgroung

Previous studies showed that maximal oxygen uptake and maximal heart rate were not different during prolonged fasting (ramadan) compared to normal feeding period. However, the effect of ramadan on the blood pressure response during incremental exercise has not been investigated.

Objective

This study aimed to evaluate the evolution of blood pressure during incremental trial in ramadan period.

Methods

Twelve young trained male aged 24 ± 4 yrs participated as voluntary subjects. Their anthropometric parameters, maximal aerobic power and maximal heart were measured in fasting and in normal feeding periods during incremental trial on cycle ergometer.

Results

No significant difference was observed in any anthropometric parameter. Maximal aerobic power of fasting period was significantly less (P < 0,05) compared to normal feeding. Heart rate at rest, at maximal exercise and during a 15 min period of recovery was not significantly affected. Systolic blood pressure of fasting period at maximal power was significantly lower than during the control period (P < 0,05).

Conclusion

Ramadan negatively influences the capacity of maximal power and cardiovascular response at maximal power.     

Uchi-komi avec charge,une approche physiologique d'un nouveau test spécifique au judo

Objective

The aim of this study was to elaborate and validate a specific test to evaluate the physical condition of judo players.

Subjects and methods

Twenty-three volunteers, males, aged 22 ± 3.62 years old took part in our experiment. They did the progressive test of Leger et al. (1984), vertical Jump test (Sargent test), Australian shuttle run test and a specific judo test.

Results

The observed results showed significant correlations between muscular power and the number of Uchi-komi on the judo test reference scale (R = 0.52, P < 0.01). Furthermore, there were other correlations between the number of Uchi-komi at the two first sets of specific judo test and the anaerobic power represented by the distance covered in 30s at the Australian shuttle test (R = 0.86, P < 0.01), also between the anaerobic capacity represented by the whole distance covered and the total number of Uchi-komi achieved at the judo test (R = 0.88, P < 0.01).

Conclusion

The test reproduces the physiological characteristics of judo fight. It is a good indicator of the judoka's physical fitness and their cardiovascular adaptation in a physical effort.     

Analyse de variables permettant la détermination du niveau d'un cycliste

Aims

We aimed to define a mathematical model allowing to foresee the level of a cyclist.

Methods

One hundred (and) six cyclists were classified according to their level and some of their physiological characteristics were measured with the threshold (4 mmol of lactate) and with the maximum values of their oxygen flow.

Results

To the threshold, power, lactatemy, age and size allow to foresee the level with an error rate of 27% ; to the maximum values, the criteria are development, flow in oxygen, lactatemy and age (error rate of 31%).

Conclusion

These results indicate that our mathematical model allows to envisage the level.     

Effets d'une complémentation nutritionnelle en vitamines et minéraux sur la chute de force et les marqueurs biologiques consécutifs à un exercice excentrique chez des personnes âgées

Purpose

The effects of vitamins and minerals complex supplementation on maximal voluntary contraction decrease (FMV) and biological markers following an eccentric exercise at old people.

Method

Sixteen elderly subjects took either placebo (Pl group) or vitamins and minerals (Isoxan Senior, NHS, Rungis, France) (group S) for 21 d before an eccentric exercise and for 3 d after the exercise. The FMV and surface EMG activity (RMS) of the vastus lateralis (VL), vastus médialis (VM) and rectus fémoris (RF) were recorded before (Pre), immediately after (Post), 24 h (Post 24) and 48 h (Post 48) after the exercise. CCVThe creatine kinase (CK), lactate déshydrogénase, malondialdéhyde, and tumor necrosis Factor (TNFα) levels were analyzed.

Results

The reduced MVC (S: 11,2 ± 4,8%; Pl: 17,8 ± 10,4%, P < 0,01) after exercise was associated with a significant reduction in RMS VL, RMS VM and RMS RF values for both groups. A faster FMV recovery appeared at 48 h for the S group (P < 0.05). CK and TNFα values increased in post-exercise.

Conclusion

A dietary supplementation of a vitamin and mineral complex does not attenuate the loss of contractile function immediately after the running exercise, and it may accelerate the recovery of maximal force capacity after 48 h by limiting the post-exercise pro-inflammatory processes.     

Puissance critique de l’enfant prépubère et de l’adulte

Aim

The aim of the study was to compare aerobic and anerobic abilities of prepubertal children and adults with the critical power concept.

Methods

Sixteen children (10.3 ± 0.9 years) and 15 adults (23.5 ± 3.6 years) performed five tests: a maximal-graded test and four constant load exercises until exhaustion. Critical power (CP) and anaerobic-work capacity (CTA) were determined from the power-1/time (P-t) linear relationship.

Results

Determination coefficients for P-t were 0.94 ± 0.05 in children and 0.96 ± 0.04 in adults. PC values were significantly (p < 0.01) lower in children (2.7 ± 0.4 W/kg) than in adults (3.1 ± 0.3 W/kg). CTA values were significantly (p < 0.001) lower in children (136.4 ± 50.8 J/kg) than in adults (247.1 ± 45.7 J/kg).

Conclusion

Satisfying determination coefficients for CP and CTA were found in children and adults. Children have a lower CP and CTA than adults. This result is in accordance with literature.     

Effet d'un entraînement en endurance sur les concentrations de l'IGF-1 plasmatique chez le rat

Introduction

The aim of this study was to determine the effects of endurance training on IGF-1, corticosterone and insulin levels in male sedentary and trained rats.

Facts

IGF-1 concentrations decrease after training (p < 0.05), those of corticosterone increase (p < 0.01) whereas insulin levels remain stable.

Conclusion

A short period of endurance training leads to catabolic state with a decrease in IGF-1 concentrations and increase in corticosterone levels.     

Factors associated with the impossibility to obtain reliable liver stiffness measurements by means of Acoustic Radiation Force Impulse (ARFI) elastography—Analysis of a cohort of 1031 subjects

Introduction

Acoustic Radiation Force Impulse (ARFI) elastography is a non-invasive technique for liver fibrosis assessment.

Aim

To assess the feasibility of ARFI elastography in a large cohort of subjects and to identify factors associated with impossibility to obtain reliable liver stiffness (LS) measurements by means of this technique.

Methods

Our retrospective study included 1031 adult subjects with or without chronic liver disease. In each subject LS was assessed by means of ARFI elastography. Failure of ARFI measurements was defined if no valid measurement was obtained after at least 10 shots and unreliable in the following situations: fewer than 10 valid shots; or median value of 10 valid measurements with a success rate (SR) < 60% and/or an interquartile range interval (IQR) ≥ 30%.

Results

Failure of LS measurements by means of ARFI was observed in 4 subjects (0.3%), unreliable measurements in 66 subjects (6.4%), so reliable measurements were obtained in 961 subjects (93.3%). In univariant analysis, the following risk factors were associated with failed and unreliable measurements: age over 58 years (OR = 0.49; 95% CI 0.30–0.80, p = 0.005), male gender (OR = 0.58; 95% CI 0.34–0.94, p = 0.04), BMI > 27.7 kg/m² (OR = 0.23, 95% CI 0.13–0.41, p < 0.0001). In multivariate analysis all the factors mentioned above were independently associated with the risk of failed and unreliable measurements.

Conclusions

Reliable LS measurements by means of ARFI elastography were obtained in 93.3% of cases. Older age, higher BMI and male gender were associated with the risk of failed and unreliable measurements, but their influence is limited as compared with Transient Elastography.     

MMP2 and MMP9 plasma levels as markers of bone remodeling: a study on young male tennis players

Introduction

Our goal is to study the effects of tennis practice in pre-pubescent boys on bone remodeling, by means of enzyme activity involved in balance of matrix remodeling (MMP2 and MMP9).

Results

Mineral bone density has been found higher in the dominant arm (P < 0.0001) as well as MMP2 and MMP9 levels in plasma (P < 0.05).

Conclusion

Tennis practice in children increases bone remodeling, which can be assessed by MMP dosage, in addition of densitometry technique.     

The role of apparent diffusion coefficient (ADC) value in the differentiation between the most common pediatric posterior fossa tumors

Background

Diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) map provide information on MRI about the cellularity of the tumor and have an important role in the pre-operative differentiation of different tumor types.

Aim

Is to evaluate the role of ADC value measurement in the differentiation between the most common pediatric posterior fossa tumors which include juvenile pilocytic astrocytoma, ependymoma and medulloblastoma.

Patients & methods

Thirty patients were retrospectively included in this study. They were referred from the Neurosurgery Department and all of them suspected to have posterior fossa SOL according to the contrast enhanced CT. All patients were subjected to conventional MRI followed by diffusion MR imaging and calculation of the ADC values.

Results

In JPA (group 1, n = 14), ADC values ranged between 2.4 and 1.3 × 10⁻³ mm²/s, ependymoma (group 2, n = 9), ADC values ranged between 1 and 1.3 × 10⁻³ mm²/s and medulloblastoma (group 3, n = 7), ADC values ranged between 0.5 and 0.9 × 10⁻³ mm²/s. Statistically significant difference in ADC value was detected between group1, group 2 and group 3, while no statistically significant difference was detected between group 1 and group 2.

Conclusion

The calculation of ADC value in the solid enhancing portion of a tumor is a simple and reliable technique for preoperative differentiation of the most common posterior fossa.     

Contrast-enhanced dynamic and diffusion-weighted MR imaging at 3.0 T to assess aggressiveness of bladder cancer

Background

Diffusion weighted magnetic resonance imaging (DWI) and dynamic contrast-enhanced (DCE) MRI have been considered useful for pathological staging and histological grading in bladder cancer. To our knowledge, no study has combined the two imaging modalities together to assess aggressiveness of bladder cancer.

Objective

To assess the clinical aggressiveness of bladder cancer with DCE MRI and DWI at 3.0 T.

Materials and methods

A total of 59 patients with 69 pathologically confirmed tumor lesions were included in this study. All patients underwent MR examination at 3.0 T basing on DWI and DCE imaging. Tumor staging and histological grade were evaluated. The aggressiveness of bladder cancer was classified as low-, intermediate-, or high-aggressiveness according to its pathological phenotype. Apparent diffusion coefficient (ADC) value and semi-quantitative parameters (wash-in rate and wash-out rate) were determined. The correlation between clinical aggressiveness and ADC value, wash-in rate and wash-out rate were analyzed. In addition, the diagnostic accuracy of the diffusion and semi-quantitative parameters were estimated using receiver operating characteristic curve (ROC).

Results

Aggressiveness of bladder cancer is negatively correlated with ADC value (r = −0.705, p < 0.0001) and wash-out rate (r = −0.719, p < 0.0001). The tumor ADC value is positively correlated with wash-out rate (r = 0.555, p < 0.0001). The diagnostic specificity and accuracy using tumor ADC value and wash-out for the tumor with size <24 mm were better than that tumors with size ≥24 mm. The sensitivity, specificity and accuracy of ADC and wash-out rate in combination in diagnosis of bladder cancer aggressiveness were 96.7%, 94.9% and 95.7%, respectively. ROC curve revealed the diagnostic performance of aggressiveness of bladder cancer using ADC value and wash-out rate were 0.928 (cut-off value: 0.905 × 10⁻³ mm²/s) and 0.891 (cut-off value: 0.685 min⁻¹), respectively.

Conclusion

ADC and wash-out rate derived from DWI and DCE-MRI at 3.0 T have good potential to assess the aggressiveness of bladder cancer and the accuracy was greater for ADC than for semi-quantitative parameters.     

Diffusion-weighted magnetic resonance imaging of head and neck squamous cell carcinomas

Objective

To evaluate whether diffusion-weighted imaging (DWI) is a reliable technique to quantify microstructural differences between head and neck squamous cell carcinomas (SCC) and tumour-free soft tissue.

Materials and methods

DWI was obtained from 20 patients with histologically proven, untreated head and neck SCC. DWI was acquired using a diffusion-weighted, navigated echo-planar imaging sequence with a maximum b-value of 800 s/mm². For an objective assessment of image quality, the signal-to-noise ratio (SNR) was calculated. Microstructural differences between vital tumour tissue and tumour-free soft tissue were quantified by calculating the apparent-diffusion-coefficients (ADC) on a pixel by pixel method.

Results

Echo-planar DWI provided good image quality in all patients (mean SNR 18.4). The mean ADC of SCC, (0.64 ± 0.28 × 10⁻³ mm²/s), was significantly (P < 0.0001) lower than that of the tumour-free soft tissue, (2.51 ± 0.82 × 10⁻³ mm²/s).

Conclusion

DWI is a reliable diagnostic tool to quantify the microstructural differences between vital tumour tissue and tumour-free soft tissue in patients with head and neck SCC.     

Contribution of power Doppler and gray-scale ultrasound of the median nerve in evaluation of carpal tunnel syndrome

Aim of the work

To assess the role of gray-scale and power Doppler ultrasound (US) of the median nerve at the wrist in evaluating carpal tunnel syndrome (CTS).

Materials and methods

Seventy-one wrists in 51 patients with CTS in addition to 50 healthy volunteers that served as the control group were enrolled in this study. The following sonographic parameters were evaluated in both patients and controls: cross sectional area of the median nerve just proximal to the tunnel inlet (CSA1), at the pisiform bone level (CSA2), the CSA difference (ΔCSA), flattening ratio of the median nerve and bowing of the flexor retinaculum. The power Doppler US was used to assess the number of nerve vessels with estimation of the vascularity score.

Results

The ΔCSA revealed an excellent discriminative ability (AUC = 0.988) in differentiating patients with CTS at an optimal cut-off value of 3.9 mm². Intraneural hypervascularization was significantly correlated with the ΔCSA of the median nerve (P < 0.001), while not significantly correlated with the age of patients, median nerve flattening ratio and bowing of flexor retinaculum.

Conclusion

The ΔCSA and vascularity score of the median nerve are important and useful sonographic parameters in evaluation of CTS.     

Gadoxetic acid-enhanced 3.0 T MRI for the evaluation of hepatic metastasis from colorectal cancer: Metastasis is not always seen as a “defect” on the hepatobiliary phase

Purpose

To determine specific imaging features of hepatic metastasis from colorectal cancer, focusing on the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI.

Materials and methods

Over a 2-year period, 79 hepatic metastatic lesions were identified from 32 patients (22 men and 10 women) who proven colorectal cancer and underwent gadoxetic acid-enhanced 3.0 T MRI. Hepatic metastases were proven pathologically in 16 patients: by surgical liver resection (n = 14) and by US-guided biopsy (n = 2). The remaining 16 patients were considered to have hepatic metastasis based on imaging studies and clinical information. Two radiologists evaluated the imaging features of each MRI sequence, including high resolution T2WI, dynamic contrast enhancement study with hepatobiliary phase, and diffusion weighted image. We also compared SI of the lesions on T2WI and HBP.

Results

T2WI showed homogeneous high SI (n = 25; 31.7%), target appearance (n = 3; 3.8%), reversed target appearance (n = 2; 2.6%), and heterogeneously high SI (n = 49; 62%). On HBP, homogeneous defect were seen in 22 lesions (27.9%), target appearance in five lesions (6.4%), reversed target appearance in two lesions (2.5%), and heterogeneous defect in 50 lesions (63.3%); including reticular (70%), partially globular (26%), and diffuse GGO-like (4%) patterns. According to the imaging features on HBP, the homogeneous defect and heterogeneous defect groups had a mean ADC value of 0.99 × 10⁻³ and 1.07 × 10⁻³ mm²/s, respectively, without statistically significant difference.

Conclusion

Hepatic metastasis from colorectal cancer usually showed as a heterogeneous defect on HBP and a heterogeneous high SI on T2WI. The generally accepted “true defect” was not a common finding in hepatic metastasis from colorectal cancer.     

Can diffusion tensor imaging predict motor power affection after moderate traumatic brain injury?

Objective

To determine whether commissural and projection fibers fractional anisotropy (FA) abnormalities can help in the prediction of long-term outcome of motor power affection after moderately severe traumatic brain injury (TBI).

Methods

MRI protocol included diffusion tensor imaging (DTI) and was performed for 32 patients with moderate TBI and 32 matched control subjects. Regions of interests were applied in the FA maps in the corpus callosum, internal capsules posterior limb, and cerebral peduncles. Results were compared in patients with motor power affection and patients without motor power affection to the control group.

Results

All patients had FA values lower than the control group with significance differences in the corpus callosum. Patient group with weakness had FA values lower than the control groups with significance differences in the posterior limb of the left internal capsules (p = 0.001) and left cerebral peduncles (p < 0.001). Significant differences were found when comparing the posterior limb of the left internal capsule (p = 0.002) and left cerebral peduncle (p = 0.022) to the right side in the weakness group.

Conclusion

FA values measured in the acute stage provided information about associated and projectional fibers disruptions, which have a prognostic value about motor power affection.     

Impact of thrombocytopenia on radiofrequency ablation therapy of hepatocellular carcinoma in patients with liver cirrhosis

Objective

The objective of our study was to assess the impact of thrombocytopenia on percutaneous radiofrequency ablation (RFA) therapy of Hepatocellular carcinoma (HCC) in patients with liver cirrhosis.

Material and methods

We analyzed retrospectively 64 patients with liver cirrhosis and thrombocytopenia, defined as a platelet count of less than 100 × 10³/mm³ that had undergone percutaneous RFA to treat 86 HCCs. The Kaplan–Meier and Cox regression methods were used to predict hemorrhage, and time to the first decompensation event, defined as the development of ascites, hepatic encephalopathy, variceal hemorrhage, and deterioration of liver function to Child-Pugh class B/C.

Results

There were no significant risk factors of hemorrhage. Univariate and multivariate analyses revealed that liver decompensation was clearly linked to prothrombin activity (p = 0.010 and p = 0.006, respectively) and a ? 63% of prothrombin activity was found as significant threshold for the occurrence of liver decompensation (p = 0.003) confirmed by the Cox model (p = 0.05).

Conclusion

Percutaneous RFA for HCC can be performed safely without the need for support, in patients with liver cirrhosis and thrombocytopenia up to 37 × 10³/mm³.     

The detection of coronary stiffness in cardiac allografts using MR imaging

Objective

To test the hypothesis that biomechanical changes are quantitatively related to morphological features of coronary arteries in heart transplant (HTx) recipients.

Materials and methods

With IRB approval, three-dimensional (3D) magnetic resonance (MR) angiography and two-dimensional (2D) black-blood stead-state free precession (SSFP) MR imaging were performed to image coronary arteries of 36 HTx patients. Contours of coronary wall were manually drawn. For each coronary segment, coronary wall thickness, wall area, lumen area (in systole and diastole) were acquired. Coronary distensibility index (CDI) and the percent of the coronary wall occupying the vessel area (PWOV) were calculated.

Results

There are totally 98 coronary segments eligible for quantitative analysis from 27 HTx patients. The CDI is 4.90 ± 2.44 mmHg⁻¹. The mean wall thickness is 1.49 ± 0.24 mm and the PWOV is 74.6% ± 7.5%. CDI has moderate correlations with wall thickness (r = −0.531, P < 0.001) and with PWOV (R = −0.435, P < 0.001).

Conclusions

Detected with coronary MR imaging, CDI is quantitatively correlated with the morphological features of the coronary artery in HTx patients. Coronary stiffness has the potential to become an alternative imaging biomarker for the quantitative assessment of the status of cardiac allografts.     

30-15 Intermittent Fitness Test et répétition de sprints

Introduction

The maximal running velocity (V_IFT) reached at the end of the 30-15 Intermittent Fitness Tests (30-15_IFT) is very well related to most physiologic determinants of team-sport performance: explosive power of lower limbs, speed, maximal aerobic power and the ability to recover between exercise bouts. Nevertheless, its relationship with repeated sprint ability (RSA) was unknown.

Synthesis of the facts

Present results in 84 team-sport athletes show that V_IFT is very well related to mean sprint time during a RSA test (p > 0.001).

Conclusion

We conclude that V_IFT is highly representative of most physiologic determinants of performance in team-sports, and could thus been used to monitor athletic performance of team-sport players.     

The role of MR diffusion in differentiation of malignant and benign hepatic focal lesions

Aim

To determine if focal liver masses could be differentiated as benign or malignant by DWI and ADC maps.

Methods and materials

Sixty focal liver lesions were scanned using 1.5 T MRI. DWI was performed with b 0, b 500 and b 1000 gradients with ADC measurements. Comparison of mean ADC values between each benign and malignant lesion was done. Reference standard of diagnosis was obtained by correlating DWI with histopathologic findings and imaging follow-up. The accuracies of DWI and ADC values were assessed with the Student’s t test, and cut-off values were determined with receiver operating characteristic curve analysis.

Results

When ADC value of 1.0 × 10⁻³ mm²/s was used as a threshold value for differentiation of malignant tumors from benign lesions, sensitivity was 90.3%, specificity 78.57% and accuracy 86.7%. The best result was obtained with the use of ADC cut off value (at b 500) of 1.5 × 10⁻³ mm²/s and ADC cut off value (at b 1000) of 1.0 × 10⁻³ mm²/s, with 90.3% sensitivity, 92.86% specificity, 91.1% accuracy, 96.6% positive predictive value and 81.3% negative predictive value.

Conclusion

DWI and ADC map is a useful tool in differential diagnosis of malignant from benign liver lesions.     

Diffusion-weighted MRI for evaluating perianal fistula activity: Feasibility study

Purpose

To assess the feasibility of using diffusion-weighted magnetic resonance (MR) imaging (DWI) for evaluating perianal fistula activity.

Materials and methods

This study retrospectively assessed 24 patients with clinically suspected perianal fistula who underwent a total of 28 MR examinations after conservative treatment with antibiotics. DWI was performed at 1.5 T, using b-values of 0 and 1000s/mm². Apparent diffusion coefficient (ADC) maps were created and ADCs of the lesions were measured. Lesions were classified into two groups based on the need for surgery and surgical findings: positive inflammation activity (PIA) and negative inflammation activity (NIA). ADCs of both groups were compared using an unpaired t-test, and Receiver Operating Characteristic (ROC) analysis was performed.

Results

The ADC (in 10⁻³ mm²/s) of the PIA group (0.908 ± 0.171) was significantly lower (P = 0.0019) than that of the NIA group (1.124 ± 0.244). The area under the ROC curve was 0.749. An optimal cut-off ADC of 1.109 yielded a sensitivity of 95.7%, a specificity of 50%, a positive predictive value of 71%, and a negative predictive value of 90%.

Conclusion

DWI is a feasible method for evaluating perianal fistula activity. The diagnostic performance of this technique should be established in future, larger prospective studies.