[Pulmonary lipofibroblasts in adults and alveolar regeneration in emphysema]. / Lipofibroblastes pulmonaires chez l'adulte et régénération alvéolaire au cours de l'emphysème.

Lipofibroblasts form a sub-population of fibroblasts located in the mesenchymal alveolar stem cell niche. They show close proximity with alveolar epithelial type 2 cells and play a key role in alveolar development and lung homeostasis. Their role in various diseases such as acute respiratory distress syndrome, pulmonary fibrosis and emphysema is progressively better understood. Through the activation of signaling pathways such as PPARg lipofibroblasts may help to induce endogenous alveolar regeneration.

The effect of body composition and serum inflammatory markers on the functional muscle-bone unit in premenopausal women.

BACKGROUND/OBJECTIVES: A number of recent studies dealing with the relationship between the effects of high body mass (BM) and fat mass (FM) on bone mass and strength exhibit a range of contrasting variations in their findings. These diverse findings have led to an ongoing controversy as to whether high BM and FM positively or negatively affect bone mass and strength. Excessive FM and the associated low-grade inflammation might overturn the higher mechanical stimulus arising from a higher BM. Therefore, we aimed at quantifying the functional muscle-bone unit in premenopausal women with markedly diverging body composition. SUBJECTS/METHODS: Sixty-four young women with BMs ranging from 50 to 113 kg and body fat percentages between 20.7% and 51.8% underwent jumping mechanography and peripheral quantitative computed tomography measurements. Maximum voluntary ground reaction force during multiple one-legged hopping (Fm1LH), as well as bone characteristics at 4, 14 and 38% of tibia length, were determined. Body composition was assessed by dual-energy X-ray absorptiometry, and serum inflammatory markers were analyzed from blood samples. RESULTS: Fm1LH predicted volumetric bone mineral content at the 14% site by 48.7%. Women with high body fat percentage had significantly higher Fm1LH, significantly lower relative bone mass, relative bone strength and relative bone area, as well as higher serum inflammatory markers in comparison to women with lower body fat percentage. CONCLUSIONS: In conclusion, high body fat percentage was associated with lower relative bone mass and strength despite normal habitual muscle force in premenopausal women, indicating that high body fat percentage compromised the functional muscle-bone unit in these individuals.

Reliability of parameters during stair ascent measured with Leonardo Mechanograph(®) Stair A in healthy subjects.

OBJECTIVES: Stair climbing (SC) as daily activity is assessed with different SC-tests, but none directly measures ground reaction force over several steps. The Leonardo Mechanograph Stair A has five steps and four force sensors. This study aimed at investigating the reliability of the Stair A test for force, power and time to SC. METHODS: 55 healthy participants (age: 48±14 years) were five times tested during SC with self-chosen and fast speed. 30 participants were examined for test-retest-reliability, calculated with the intraclass correlation coefficient (ICC). The variability was examined with the coefficient of variation (CV). To determine potential associations between SC and jumping performance or daily activity, squat and countermovement jumps were additionally performed and the International physical activity questionnaire (IPAQ) was completed. RESULTS: The inter-visit ICCs of self-chosen and fast SC were good to excellent 0.63-0.77. The intra-visit ICCs were excellent after three trials (0.78-0.88). The CVs for SC with self-chosen speed were lower (2.1-6.6%) than those for fast SC (4.9-10.8%). There were no significant correlations between SC and jump parameters and only moderate correlations with the IPAQ. CONCLUSION: The Stair A is a reliable tool for the assessment of SC.

Functional assessment of the muscle-bone unit in the lower leg.

Based on the mechanostat theory and the muscle-bone hypothesis, a methodological assessment of the musculoskeletal status in health and disease should relate maximum muscle force in relation to bone mass and geometry. While useful (i.e. three-dimensional) measures of tibial bone parameters can be obtained by peripheral quantitative computed tomography (pQCT), intrinsic plantarflexor muscle force cannot be directly measured under in vivo condition in humans. Instead, tissue size, torque and ground reaction force have been used as proxy markers of intrinsic muscle force. However, most of these proxy markers are not or insufficiently representative of maximum force. Based on our recent research, we describe a novel approach for the assessment of the lower leg muscle-bone unit in health and disease. It incorporates multiple one-legged hopping (m1LH) to assess maximum voluntary ground reaction force acting on the forefoot (F(m1LH)) and bone mineral content at the 14%-site of tibia length (vBMC(14%)) as assessed by pQCT. Using the quantitative relationship between these two variables in conjunction with F(m1LH) per body weight, we present a two-step quantitative diagnostic algorithm to discriminate between primary and secondary bone disorders in children and adults.

Effects of jumping exercise on maximum ground reaction force and bone in 8- to 12-year-old boys and girls: a 9-month randomized controlled trial.

OBJECTIVES: To assess adaptations of the lower leg muscle-bone unit in 8- to 12-year-old children following a randomized controlled jumping exercise intervention for 9 months. METHODS: Twelve boys and 10 girls (INT) performed a supervised jumping protocol during the first 10 min of their regularly scheduled physical education class twice a week, while 11 boys and 12 girls (CON) completed the regular curriculum. We assessed maximum voluntary ground reaction force during multiple one-legged hopping (F(m1LH)), and tibial bone strength/geometry by peripheral quantitative computed tomography (pQCT) at the 4-, 14-, 38- and 66%-site pre, intermediate, and post intervention. RESULTS: Whether increases in F(m1LH) (+2.1% points, P= 0.752), nor changes in bone strength/geometry (+1 to +3% points, 0.169

Combined effects of whole-body vibration, resistance exercise, and vascular occlusion on skeletal muscle and performance.

The purpose of this study was to evaluate the effects of a new high-intensity training modality comprised of vibration exercise with superimposed resistance exercise and vascular occlusion (vibroX) on skeletal muscle and performance. Young untrained women were randomized to either train in a progressive mode on 3 days per week for 5 weeks ( N=12) or to maintain a sedentary lifestyle ( N=9). VibroX increased peak cycling power (+9%, P=0.001), endurance capacity (+57%, P=0.002), ventilatory threshold (+12%, P<0.001), and end-test torque (+15%, P=0.002) relative to the sedentary group. Training load increased by 84.5% ( P<0.001) after vibroX. The increases were paralleled by increases in myosin heavy chain type 1 vastus lateralis muscle fiber cross-sectional area (+14%, P=0.031) and proportion (+17%, P=0.015), thigh lean mass (+4%, P=0.001), capillary-to-fiber ratio (+14%, P=0.003), and cytochrome c oxidase activity. Conversely, maximal values for oxygen consumption, cardiac output, isokinetic leg extension power and jumping power remained unaffected. Notably, vastus lateralis muscle adaptations were achieved with a very low weekly training volume. We conclude that vibroX quickly increases muscle (fiber) size, capillarization, and oxidative potential, and markedly augments endurance capacity in young women.

Ultrasound detects joint damage and bleeding in haemophilic arthropathy: a proposal of a score.

Haemarthrosis triggers haemophilic arthropathy (HA) because bleeding starts synovitis immediately, damages cartilage and leads to loss of function and disability. The aim of our study was to investigate the capacity of ultrasonography (US) in detecting bleeding and joint damage in HA. The joints of 62 patients (pts) with haemophilia A or haemophilia B were consecutively evaluated and scored (score ranging from 0 to 21) for effusion (E), bone remodelling (BR), cartilage damage (CD), synovial hypertrophy (SH), haemosiderin (H), osteophytes (O), haemarthrosis (Hae), erosion (Er) and fibrotic septa (FS) with US. X-rays [Pettersson Score (PXS)] were performed in 61 patients and clinical evaluation [World Federation Haemophiliac orthopaedic score (WFHO)] was performed in all patients. A total of 20 healthy subjects and 20 patients affected by Rheumatoid Arthritis (RA) were used as controls. Power Doppler US (PDUS) was performed in all patients on the knee, ankle and elbow joints. A total of 83 joints were studied (50 knees; 12 elbows and 21 ankles). US showed effusion in 57 joint, bone remodelling in 62, cartilage damage in 64, synovial hypertrophy in 45, haemosiderin in 39, osteophytes in 30, haemarthrosis in 24, erosion in 5 and fibrotic septa in 3. The X-rays score showed remodelling in 47 joints, narrowing joint space in 44, displacement/angulation in 39, osteoporosis in 42, subchondral irregularity in 44, subchondral cyst formation in 37, osteophytes in 36 and erosions in 25. The US score in healthy subjects was always ≤ 5 (range 0 to 4). In haemophiliacs, 34 of 83 joints showed US score ≤ 5, and 49 US score > 5. Joints with US score ≤ 5 had a low PXS (SRCC = 0.375, P < 0.01) and joints with US score > 5 showed a high PXS (SRCC = 0.440, P < 0.01). A significant correlation between US score and PXS for bone remodelling [Spearman's rho Correlation Coefficient (SRCC) = 0.429, P < 0.01] and for osteophytes (SRCC = 0.308, P < 0.05) was found. The correlation between the US score and number of bleedings in 83 joints was very significant (SRCC = 0.375, P < 0.01). A total of 24 bleeding joints were identified and verified with aspiration of haematic fluid. US may detect bone and cartilage alterations and synovitis. Indeed, PDUS identified bleeding also in asymptomatic joints and was able to show different entity of haemarthrosis. US may be a feasible and reliable tool to evaluate joint modifications in HA.

Effects of a 12-week intervention period with football and running for habitually active men with mild hypertension.

The present study examined the effect of football (F, n=15) training on the health profile of habitually active 25-45-year-old men with mild hypertension and compared it with running (R, n=15) training and no additional activity (controls, C, n=17). The participants in F and R completed a 1-h training session 2.4 times/week for 12 weeks. Systolic and diastolic blood pressure decreased in all groups but the decrease in diastolic blood pressure in F (-9 +/- 5 (+/- SD) mmHg) was higher than that in C (-4 +/- 6 mmHg). F was as effective as R in decreasing body mass (-1.6 +/- 1.8 vs-1.5 +/- 2.1 kg) and total fat mass (-2.0 +/- 1.5 vs -1.6 +/- 1.5 kg) and in increasing supine heart rate variability, whereas no changes were detected for C. Maximal stroke volume improved in F (+13.1%) as well as in R (+10.1%) compared with C (-4.9%). Total cholesterol decreased in F (5.8 +/- 1.2 to 5.5 +/- 0.9 mmol/L) but was not altered in R and C. We conclude that football training, consisting of high-intensity intermittent exercise, results in positive effects on blood pressure, body composition, stroke volume and supine heart rate variability, and elicits at least the same cardiovascular health benefits as continuous running exercise in habitually active men with mild hypertension.

Reliability of measurements with Innocor during exercise.

Cardiac output represents the primary determinant of cardiovascular function. Therefore, understanding how cardiac output is regulated during exercise is crucial. A recently developed tool for determining cardiac output is the Innocor rebreathing system, which also incorporates an ergospirometry unit. So far, Innocor's test-retest reliability under exercise conditions has not been determined in healthy participants. Therefore, 15 male and 15 female healthy participants [30.6 y (SD 4.5); 68.0 kg (SD 10.5)] performed 2 test sessions, each consisting of 2 graded exercise tests to volitional exhaustion. We determined intra- and inter-session reliability of cardiac output, oxygen consumption, carbon dioxide output, and ventilation at 130 W and at peak exercise. For cardiac output, we found averaged coefficients of variation ranging from 4.3 (intra-session, 130 W) to 10.0% (inter-session, rest). For oxygen consumption, coefficients of variation ranged from 3.4 (intra-session, peak) to 5.7% (inter-session, peak). Coefficients of variation for carbon dioxide output were between 4.4 (intra-session, peak) and 6.6% (inter-session, peak), and for ventilation between 5.1 (intra-session, 130 W) and 7.0% (intra-session, peak). Innocor delivers safe and reliable measurements of cardiac output, gas exchange, and ventilation. Therefore, Innocor can be used to assess these parameters in exercise physiology studies as well as in performance diagnostics.

[Emigration, development, and independence: the Tunisian case]. / Emigrazione, sviluppo e dipendenza: il caso della Tunisia.

"This article studies migration from the poor countries of the South to those of the rich North, with special reference to the case of Tunisia. The study is divided into two parts. The first...outlines a brief history of Tunisian migration and underlines the active role taken by governmental organizations in promoting and controlling migratory flows, seen in their twofold goals of patching up internal inequities and, at the same time, boosting development. Statistical data regarding flows towards the most popular destinations are reported, along with possible developments in the future. The second looks at...whether migration is good for the sending country." (SUMMARY IN ENG AND FRE)