Endurance exercise preserves physical function in adult and older male C57BL/6 mice: high intensity interval training (HIIT) versus voluntary wheel running (VWR)

Exercise has been shown to improve physical function, mitigate aspects of chronic disease and to potentially alter the trajectory of age-related onset of frailty and sarcopenia. Reliable and valid preclinical models are necessary to elucidate the underlying mechanisms at the intersection of age, exercise, and functional decline. The purpose of this study was to compare, head to head, the effects of two common pre-clinical models of endurance exercise: high intensity interval training (HIIT) and voluntary wheel running (VWR). The hypothesis was that a prescribed and regimented exercise program, HIIT, would prove to be a superior training method to unregulated voluntary exercise, VWR. To investigate this hypothesis, we evaluated adult (n = 24, designated 10 m, aged 6 months at the beginning of the study, 10 months at its completion) and older adult (n = 18, designated 26 m, aging from 22 months to 26 months over the course of the study) C57BL/6 male mice. These mice were randomly assigned (with selection criteria) to a 13-week program of voluntary wheel running (VWR), high intensity interval training (HIIT), or sedentary control (SED). The functional aptitude of each mouse was determined pre- and post-training using our composite CFAB (comprehensive functional assessment battery) scoring system consisting of voluntary wheel running (volitional exercise and activity rate), treadmill (endurance), rotarod (overall motor function), grip meter (forelimb strength), and inverted cling (whole body strength/endurance). To measure sarcopenia, we tracked body mass, body composition (with EchoMRI), plantar flexor torque (in 10 m), and measured muscle wet mass post-training. Overall, adult CFAB scores decreased while body mass and percent body fat increased as they matured; however, exercise significantly mitigated the changes (p < 0.05) compared to SED. Older adults demonstrated preservation of function (CFAB) and reduced body fat (p < 0.05) compared to SED. To conclude, both types of exercise maintained physical function equally in older mice.

Viscosimetric squeeze flow of suspensions

The rheology of particle suspensions has been extensively explored in the case of a simple shear flow, but less in other flow configurations which are also important in practice. Here we investigate the behavior of a suspension in a squeeze flow, which we revisit using local pressure measurements to deduce the effective viscosity. The flow is generated by approaching a moving disk to a fixed wall at constant velocity in the low Reynolds number limit. We measure the evolution of the pressure field at the wall and deduce the effective viscosity from the radial pressure drop. After validation of our device using a Newtonian fluid, we measure the effective viscosity of a suspension for different squeezing speeds and volume fractions of particles. We find results in agreement with the Maron-Pierce law, an empirical expression for the viscosity of suspensions that was established for simple shear flows. We prove that this method to determine viscosity remains valid in the limit of large gap width. This makes it possible to study the rheology of suspensions within this limit and therefore suspensions composed of large particles, in contrast to Couette flow cells which require small gaps.

Rheology of granular rafts

Rheology of macroscopic particle-laden interfaces, called "granular rafts," has been experimentally studied in the simple shear configuration. The shear-stress relation obtained from a classical rheometer exhibits the same behavior as a Bingham fluid, and the viscosity diverges with the surface fraction according to evolutions similar to 2D suspensions. The velocity field of the particles that constitute the granular raft has been measured in the stationary state. These measurements reveal nonlocal rheology similar to dry granular materials. Close to the walls of the rheometer cell, one can observe regions of large local shear rate while in the middle of the cell a quasistatic zone exists. This flowing region, characteristic of granular matter, is described in the framework of an extended kinetic theory showing the evolution of the velocity profile with the imposed shear stress. Measuring the probability density functions of the instantaneous local shear rate, we provide evidence of a balance between positive and negative instantaneous local shear rate. This behavior is the signature of a quasistatic region inside the granular raft.

Successive reintrusions in a granular medium

We measure and analyze the drag force experienced by a rigid rod that penetrates vertically into a granular medium and partially withdraws before sinking again. The drag during the successive reintrusions is observed to be significantly smaller than the force experienced in the first run. Two force regimes are evidenced depending on how the reintrusion depth compares with the withdrawal distance Δ. These two regimes are characterized by a force curve of positive and negative curvature and are separated by an inflection point, which is characterized experimentally. We approach the difference between the first intrusion and the following reintrusions by considering a modification in the stress field of the granular material after the partial extraction of the rod. A theoretical model for the stress modification is proposed and allows to rationalize all the experiments realized for different withdrawal distances Δ. This framework introduces a crossover length λ above which the stress modification in the granular medium is maintained and that is shown to depend linearly on Δ. Finally, the model provides a prediction for the location of the inflection points in reasonable agreement with observations.

Added-mass force in dry granular matter

From two-dimensional (2D) numerical simulations of the motion of a circular intruder into a dry granular packing, we provide evidence for a specific force term in the case of unsteady motion in addition to the force corresponding to a steady motion. We show that this additional term is proportional to the acceleration of the intruder relative to the grains as the added-mass force known for simple fluids. This force term corresponds to a variation in the kinetic energy of the surrounding flow and is characterized by a coefficient C_{AM} which is intrinsically linked to the nature of the granular media. An analytical calculation of the added-mass coefficient C_{AM} is developed based on the specific velocity field known for 2D granular flow around a cylinder. The theoretical value is shown to depend on the grain-cylinder size ratio, in good agreement with the measurements from our unsteady simulations.

Maintenance of Physical Function in Adult and Older Adult Mice Using Aerobic Exercise

As we age, physical and neuromuscular function declines gradually. Exercise is a therapy to improve neuromuscular ability. Pre-clinical models are needed to understand molecular mechanisms contributing to age-associated functional decline and how exercise affects that downward trajectory. Our goal was to compare the differences in effects of two validated mouse models of endurance exercise designed to mimic human training studies: high intensity interval training (HIIT) and voluntary wheel running (VWR). We hypothesized that both adult and older adults (10 and 26 months old at end, respectively: 10m and 26m) would respond to both exercise regimens by improving or maintaining exercise/physical capacity, but that adult mice would benefit more. We randomly assigned male C57BL/6 mice into experimental groups: 10m: (VWR, HIIT, sedentary control, CON, n=8 per group), and 26m (VWR, n=8, HIIT, n=10). We measured functional ability (pre- and post-intervention) using CFAB (comprehensive functional assessment battery), our composite scoring system (grip strength, inverted cling, treadmill endurance, activity rate, rotarod), tracked body composition (EchoMRI), and measured muscle wet mass. We found that significant retention of ability (CFAB difference, repeated measures ANOVA, p<0.05) and fat percentage (ANOVA., %change: 10m: CON +125%, HIIT +101%, VWR +52%; 26m: VWR -42%, HIIT +26%, p<0.05) was promoted by both exercise modalities compared to control, and furthermore HIIT may have better efficacy in the adult versus the older mice. In conclusion, both exercises are valid models with derived benefits as expected in similar human studies. We anticipate future work using these models to undertake mechanistic investigations.

Endurance Exercise Training Modes to Improve Physical Function in Older Mice: HIIT vs. VWR

With age, we experience a progressive loss of physical function. Exercise is a promising therapy to preserve muscle health and functional aptitude. Animal models are needed to examine the underlying molecular mechanisms at the intersection of aging, exercise, and functional decline. In this study, we compare the efficacy of two types of individualized endurance exercise training in older C57BL/6 mice (26-months old at completion): HIIT (high intensity interval training on a treadmill, n=10) and VWR (voluntary wheel running, n=8). We hypothesized that while both exercises would improve function, HIIT would promote more extensive adaptation. For four months the VWR mice ran 4 days/week and the HIIT group ran 3x/week. We determined function pre/post-training by utilizing our composite scoring system, the Comprehensive Functional Assessment Battery (CFAB). CFAB consists of the following: treadmill running (endurance), rotarod (overall motor function), wheel running (volitional exercise rate/activity), grip strength (fore-limb strength), and inverted cling (overall strength/endurance). EchoMRI determined body composition. After training, we found significant CFAB improvement (repeated measures t-test, p&lt;0.05) in both exercise groups, specifically including: rotarod (+37%, HIIT and VWR); treadmill (+61% VWR; +58% HIIT), grip strength (+20% VWR), body mass (-17% VWR, -10% HIIT), and fat percentage (-44% VWR, -20% HIIT). Contrary to our hypothesis, HIIT did not improve function more than VWR, though we suspect increasing training intensity would improve response. Thus, future studies will need to address defining HIIT dose response and optimal training volume for older mice. We conclude that our models will be useful for future mechanistic investigations.

Nationwide survey on training and device utilization during tracheal intubation in French intensive care units

Background

Intubation is a lifesaving procedure that is often performed in intensive care unit (ICU) patients, but leads to serious adverse events in 20–40% of cases. Recent trials aimed to provide guidance about which medications, devices, and modalities maximize patient safety. Videolaryngoscopes are being offered in an increasing range of options and used in broadening indications (from difficult to unremarkable intubation). The objective of this study was to describe intubation practices and device availability in French ICUs.

Materials and methods

We conducted an online nationwide survey by emailing an anonymous 26-item questionnaire to physicians in French ICUs. A single questionnaire was sent to either the head or the intubation expert at each ICU.

Results

Of 257 ICUs, 180 (70%) returned the completed questionnaire. The results showed that 43% of intubators were not fully proficient in intubation; among them, 18.8% had no intubation training or had received only basic training (lectures and observation at the bedside). Among the participating ICUs, 94.4% had a difficult intubation trolley, 74.5% an intubation protocol, 92.2% a capnography device (used routinely to check tube position in 69.3% of ICUs having the device), 91.6% a laryngeal mask, 97.2% front-of-neck access capabilities, and 76.6% a videolaryngoscope. In case of difficult intubation, 85.6% of ICUs used a bougie (154/180) and 7.8% switched to a videolaryngoscope (14/180). Use of a videolaryngoscope was reserved for difficult intubation in 84% of ICUs (154/180). Having a videolaryngoscope was significantly associated with having an intubation protocol (P = 0.043) and using capnography (P = 0.02). Airtraq^® was the most often used videolaryngoscope (39.3%), followed by McGrath^®Mac (36.9%) then by Glidescope^® (14.5%).

Conclusion

Nearly half the intubators in French ICUs are not fully proficient with OTI. Access to modern training methods such as simulation is inadequate. Most ICUs own a videolaryngoscope, but reserve it for difficult intubations.

Hysteresis of the drag force of an intruder moving into a granular medium

We numerically investigate the force-displacement relation of a moving intruder initially at rest into a granular medium. Our model granular medium is composed of one layer of coplanar polydisperse spheres subjected to a gravity field. The interactions between the grains are modelled by Hertzian contacts to which a viscous damping is applied. Moving it horizontally and with alternating positive and negative velocity, we recover a hysteresis of the force-displacement curve. Considering that the flow is plastic as the yield strength has been reached, we describe the transient part of the flow around the intruder. We show that the drag stress increases as its distance to an ultimate drag stress [Formula: see text] with a typical deformation [Formula: see text]: the drag stress-strains curve appears to exponentially decay as it saturates to this ultimate drag stress. This protocol of deformation highlights that the deformation of the grains is negligible compared to the deformation of the packing, i.e. related to the irreversible displacements of grains allowing the intruder to pass through. Simultaneously, the lift force is constant on average during the displacement of the intruder. We then give the different scaling laws of the yield strength, this ultimate drag stress, the characteristic deformation of the packing and the lift stress. Finally, we recover the complete hysteresis cycle of the drag force around the intruder.

Severe atypical pneumonia in critically ill patients: a retrospective multicenter study

BACKGROUND

Chlamydophila pneumoniae (CP) and Mycoplasma pneumoniae (MP) patients could require intensive care unit (ICU) admission for acute respiratory failure.

METHODS

Adults admitted between 2000 and 2015 to 20 French ICUs with proven atypical pneumonia were retrospectively described. Patients with MP were compared to Streptococcus pneumoniae (SP) pneumonia patients admitted to ICUs.

RESULTS

A total of 104 patients were included, 71 men and 33 women, with a median age of 56 [44-67] years. MP was the causative agent for 76 (73%) patients and CP for 28 (27%) patients. Co-infection was documented for 18 patients (viruses for 8 [47%] patients). Median number of involved quadrants on chest X-ray was 2 [1-4], with alveolar opacities (n = 61, 75%), interstitial opacities (n = 32, 40%). Extra-pulmonary manifestations were present in 34 (33%) patients. Mechanical ventilation was required for 75 (72%) patients and vasopressors for 41 (39%) patients. ICU length of stay was 16.5 [9.5-30.5] days, and 11 (11%) patients died in the ICU. Compared with SP patients, MP patients had more extensive interstitial pneumonia, fewer pleural effusion, and a lower mortality rate [6 (8%) vs. 17 (22%), p = 0.013]. According MCA analysis, some characteristics at admission could discriminate MP and SP. MP was more often associated with hemolytic anemia, abdominal manifestations, and extensive chest radiograph abnormalities. SP-P was associated with shock, confusion, focal crackles, and focal consolidation.

CONCLUSION

In this descriptive study of atypical bacterial pneumonia requiring ICU admission, mortality was 11%. The comparison with SP pneumonia identified clinical, laboratory, and radiographic features that may suggest MP or CP pneumonia.

Buckling of a rod penetrating into granular media

We investigate experimentally the possible buckling of a thin rod when penetrating downwards into a granular packing. When its bottom end reaches a specific depth, the rod may start buckling provided that the embrace is not enough to stop that phenomenon. The critical rod depth z_{c} at buckling is observed to scale with the rod length L either as 1/L or 1/L^{2}. These two scalings are shown to arise from the two resistant force terms that come into play during the rod penetration: a pressure force at the bottom of the rod that increases linearly with depth and a frictional force on the rod side that increases quadratically with depth. At the buckling point, the destabilizing force corresponds to the expected value given from conventional Euler's critical load for a rod bottom end considered as fixed in the granular clutch. Finally, we draw a buckling-nonbuckling phase diagram in a parameter space given by the rod aspect ratio and a rod-to-grain stress ratio.

Drag force in a cold or hot granular medium

We measure experimentally and analyze the resisting force exerted by a bidimensional packing of small disks on a larger intruder disk dragged horizontally at constant velocity V_{0}. Depending on the vibration level of the packing that leads to a granular "cold" or "hot" packing, two force regimes are observed. At low vibration level ("cold" granular medium), the drag force F does not depend on V_{0}, whereas for high vibrations ("hot" granular medium), the drag force increases linearly with V_{0}. Both regimes can be understood by the balance of two "granular temperatures" that can be defined in the system: a bulk temperature T_{b} imposed by the external vibration to the overall packing and a local temperature T_{0} induced by the own motion of the intruder disk in its vicinity. All experimental data obtained for different sizes and velocities of the intruder disk are shown to be governed by the temperature ratio T_{0}/T_{b}. A critical velocity V_{0c}, above which the system switches from "hot" to "cold," can be obtained in this frame. Finally, we discuss how these two "viscous" regimes should be followed by an inertial regime where the drag force F should increase as V_{0}^{2} at high enough velocity values, for V_{0} greater than a critical value V_{0i} corresponding to high enough Reynolds or Froude number.

[A case of mediastinum actinomycosis by Aggregatibacter actinomycetemcomitans]

The actinomycosis is a suppurative infection due to an anaerobic and microaerophillic bacteria called actinomyces. Only few case reports are described for the mediastinal locations of this rare entity. We report a new case of inflammatory pseudotumor in the mediastinum due to Aggregatibacte actinomycetemcomitans revealed by hemoptysis. The mediastinoscopy procedure with biopsy was needed to confirm the definitive bacteriological diagnosis by a positive culture. During the postoperative course, a cutaneous fistula was found which had a favourable evolution after appropriate antibiotherapy. Through this case report, the authors insist upon the importance of considering the diagnosis of mediastinal actinomycosis when facing non-specfic mediastinal mass symptoms and also about the interest of systematic bacterioscopic examination and histopathologic examination on nodes' biopsies to avoid to be lost on pathology of mediastinal tumor or tuberculosis. In practise, we caution the non-expert during biopsies because of this lesion's invasive characteristic especially in the confined space of the mediastinum.

Experimental Evidence of the Gardner Phase in a Granular Glass

Analyzing the dynamics of a vibrated bidimensional packing of bidisperse granular disks below jamming, we provide evidence of a Gardner phase deep into the glass phase. To do so, we perform several compression cycles within a given realization of the same glass and show that the particles select different average vibrational positions at each cycle, while the neighborhood structure remains unchanged. The separation between the cages obtained for different compression cycles plateaus with an increasing packing fraction, while the mean square displacement steadily decreases. This phenomenology is strikingly similar to that reported in recent numerical observations when entering the Gardner phase, for a mean-field model of glass as well as for hard spheres in finite dimension. We also characterize the distribution of the cage order parameters. Here we note several differences from the numerical results, which could be attributed to activated processes and cage heterogeneities.

Clustering and flow around a sphere moving into a grain cloud

A bidimensional simulation of a sphere moving at constant velocity into a cloud of smaller spherical grains far from any boundaries and without gravity is presented with a non-smooth contact dynamics method. A dense granular "cluster" zone builds progressively around the moving sphere until a stationary regime appears with a constant upstream cluster size. The key point is that the upstream cluster size increases with the initial solid fraction [Formula: see text] but the cluster packing fraction takes an about constant value independent of [Formula: see text]. Although the upstream cluster size around the moving sphere diverges when [Formula: see text] approaches a critical value, the drag force exerted by the grains on the sphere does not. The detailed analysis of the local strain rate and local stress fields made in the non-parallel granular flow inside the cluster allows us to extract the local invariants of the two tensors: dilation rate, shear rate, pressure and shear stress. Despite different spatial variations of these invariants, the local friction coefficient μ appears to depend only on the local inertial number I as well as the local solid fraction, which means that a local rheology does exist in the present non-parallel flow. The key point is that the spatial variations of I inside the cluster do not depend on the sphere velocity and explore only a small range around the value one.

Local rheological measurements in the granular flow around an intruder

The rheological properties of granular matter within a two-dimensional flow around a moving disk is investigated experimentally. Using a combination of photoelastic and standard tessellation techniques, the strain and stress tensors are estimated at the grain scale in the time-averaged flow field around a large disk pulled at constant velocity in an assembly of smaller disks. On the one hand, one observes inhomogeneous shear rate and strongly localized shear stress and pressure fields. On the other hand, a significant dilation rate, which has the same magnitude as the shear strain rate, is reported. Significant deviations are observed with local rheology that justify the need of searching for a nonlocal rheology.

Cardiac troponin-I on diagnosis predicts early death and refractoriness in acquired thrombotic thrombocytopenic purpura. Experience of the French Thrombotic Microangiopathies Reference Center

BACKGROUND

Cardiac involvement is a major cause of mortality in patients with thrombotic thrombocytopenic purpura (TTP). However, diagnosis remains underestimated and delayed, owing to subclinical injuries. Cardiac troponin-I measurement (cTnI) on admission could improve the early diagnosis of cardiac involvement and have prognostic value.

OBJECTIVES

To assess the predictive value of cTnI in patients with TTP for death or refractoriness.

PATIENTS/METHODS

The study involved a prospective cohort of adult TTP patients with acquired severe ADAMTS-13 deficiency (< 10%) and included in the registry of the French Reference Center for Thrombotic Microangiopathies. Centralized cTnI measurements were performed on frozen serum on admission.

RESULTS

Between January 2003 and December 2011, 133 patients with TTP (mean age, 48 ± 17 years) had available cTnI measurements on admission. Thirty-two patients (24%) had clinical and/or electrocardiogram features. Nineteen (14.3%) had cardiac symptoms, mainly congestive heart failure and myocardial infarction. Electrocardiogram changes, mainly repolarization disorders, were present in 13 cases. An increased cTnI level (> 0.1 μg L(-1) ) was present in 78 patients (59%), of whom 46 (59%) had no clinical cardiac involvement. The main outcomes were death (25%) and refractoriness (17%). Age (P = 0.02) and cTnI level (P = 0.002) showed the greatest impact on survival. A cTnI level of > 0.25 μg L(-1) was the only independent factor in predicting death (odds ratio [OR] 2.87; 95% confidence interval [CI] 1.13-7.22; P = 0.024) and/or refractoriness (OR 3.03; 95% CI 1.27-7.3; P = 0.01).

CONCLUSIONS

A CTnI level of > 0.25 μg L(-1) at presentation in patients with TTP appears to be an independent factor associated with a three-fold increase in the risk of death or refractoriness. Therefore, cTnI level should be considered as a prognostic indicator in patients diagnosed with TTP.

Shear modulus and dilatancy softening in granular packings above jamming

We investigate experimentally the mechanical response to shear of a monolayer of bidisperse frictional grains across the jamming transition. We inflate an intruder inside the packing and use photoelasticity and tracking techniques to measure the induced shear strain and stresses at the grain scale. We quantify experimentally the constitutive relations for strain amplitudes as low as 10(-3) and for a range of packing fractions within 2% variation around the jamming transition. At the transition strong nonlinear effects set in: both the shear modulus and the dilatancy shear soften at small strain until a critical strain is reached where effective linearity is recovered. The scaling of the critical strain and the associated critical stresses on the distance to jamming are extracted. We check that the constitutive laws, together with mechanical equilibrium, correctly predict to the observed stress and strain profiles. These profiles exhibit a spatial crossover between an effective linear regime close to the inflater and the truly nonlinear regime away from it. The crossover length diverges at the jamming transition.

Diagnostic contribution from pulmonary biopsies in hematology patients with acute respiratory failure from undetermined etiology

BACKGROUND

In about 20% of patients with malignancies with acute respiratory failure (ARF), no etiology can be determined, whatever the diagnostic strategy used. Lung biopsy could then be a precious diagnostic tool leading to therapeutic adaptations and increasing chances for cure. The aim of this study was to assess the diagnostic contribution of lung biopsy in patients for whom a complete diagnosis strategy failed to identify ARF etiology.

METHODS

All hematology patients admitted for ARF to our ICU between 1995 and 2011, and for whom lung biopsy was performed were included in the study. Lung biopsies were surgical, CT guided, or post-mortem. Histological findings were compared to prebiopsy diagnosis and classified into specific or non-specific diagnosis. Therapeutic impact (or Goldman-class in post-mortem biopsies) was also recorded.

RESULTS

Among the 1440 hematology patients with ARF managed during the study period, 21 (1%) biopsies were performed, including 10 post-mortem biopsies. Histological diagnoses were specific in 10 biopsies, non specific in 8 biopsies and lung parenchyma was normal in three patients. In 8/11 (72.7%) alive patients, lung biopsy had lead to therapeutic modifications, including treatment implementation in 5 patients and treatment withdrawal in 3 patients. One out of 10 (10%) patients had minor complications. For the 10 dead patients, only one Goldman-type 1 error was found.

CONCLUSION

Diagnostic lung biopsy is rarely needed in hematology patients with ARF. But, it has a 73% therapeutic impact and has overall no major complications. Contribution from post-mortem biopsies seems less relevant.

Experimental velocity fields and forces for a cylinder penetrating into a granular medium

We present here a detailed granular flow characterization together with force measurements for the quasi-bidimensional situation of a horizontal cylinder penetrating vertically at a constant velocity in dry granular matter between two parallel glass walls. In the velocity range studied here, the drag force on the cylinder does not depend on the velocity V(0) and is mainly proportional to the cylinder diameter d. While the force on the cylinder increases with its penetration depth, the granular velocity profile around the cylinder is found to be stationary with fluctuations around a mean value leading to the granular temperature profile. Both mean velocity profile and temperature profile exhibit strong localization near the cylinder. The mean flow perturbation induced by the cylinder decreases exponentially away from the cylinder on a characteristic length λ that is mainly governed by the cylinder diameter for a large enough cylinder/grain size ratio d/d(g): λ~d/4+2d(g). The granular temperature exhibits a constant plateau value T(0) in a thin layer close to the cylinder of extension δ(T(0))~λ/2 and decays exponentially far away with a characteristic length λ(T) of a few grain diameters (λ(T)~3d(g)). The granular temperature plateau T(0) that scales as V(0)(2)d(g)/d is created by the flow itself from the balance between the "granular heat" production by the shear rate V(0)/λ over δ(T(0)) close to the cylinder and the granular dissipation far away.

[Surgical lung biopsy: Indications and therapeutic implications]

Surgical biopsy of lung parenchyma can be used to establish a diagnosis in interstitial lung disease both of acute and chronic presentation. The present article summarizes the current indications, the therapeutic implications, the different surgical techniques and postoperative complications of the procedure. Common controversies and problems related to surgical lung biopsy are also presented.

Dexamethasone in patients with acute lung injury from acute monocytic leukaemia

The use of steroids is not required in myeloid malignancies and remains controversial in patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). We sought to evaluate dexamethasone in patients with ALI/ARDS caused by acute monocytic leukaemia (AML FAB-M5) via either leukostasis or leukaemic infiltration. Dexamethasone (10 mg every 6 h until neutropenia) was added to chemotherapy and intensive care unit (ICU) management in 20 consecutive patients between 2005 and 2008, whose data were compared with those from 20 historical controls (1994-2002). ICU mortality was the primary criterion. We also compared respiratory deterioration rates, need for ventilation and nosocomial infections. 17 (85%) patients had hyperleukocytosis, 19 (95%) had leukaemic masses, and all 20 had severe pancytopenia. All patients presented with respiratory symptoms and pulmonary infiltrates prior to AML FAB-M5 diagnosis. Compared with historical controls, dexamethasone-treated patients had a significantly lower ICU mortality rate (20% versus 50%; p = 0.04) and a trend for less respiratory deterioration (50% versus 80%; p = 0.07). There were no significant increases in the rates of infections with dexamethasone. In conclusion, in patients with ALI/ARDS related to AML FAB-M5, adding dexamethasone to conventional chemotherapy seemed effective and safe. These results warrant a controlled trial of dexamethasone versus placebo in AML FAB-M5 patients with noninfectious pulmonary infiltrates.

Dense granular flow around a penetrating object: experiment and hydrodynamic model

We present in this Letter experimental results on the bidimensional flow field around a cylinder penetrating into dense granular matter, together with drag force measurements. A hydrodynamic model based on extended kinetic theory for dense granular flow reproduces well the flow localization close to the cylinder and the corresponding scalings of the drag force, which is found to not depend on velocity, but linearly on the pressure and on the cylinder diameter and weakly on the grain size. Such a regime is found to be valid at a low enough "granular" Reynolds number.

[Old Monteggia lesions in children. Apropos of 14 cases]

Fourteen patients between the ages of 3.5 years and 11 years, with an old Monteggia lesion were managed in the Orthopaedics department between 1968 and 1997. Dislocation of the radial head was not diagnosed at the time of the initial trauma in 9 out of 14 cases and the diagnosis was made an average of 14 months after the trauma (range: 5 weeks to 84 months). Twelve of the 14 patients underwent surgical reduction of chronic dislocation of the radial head, mostly associated with proximal ulnar osteotomy and/or a procedure on the extensor retinaculum. The mean follow-up is 4 years 9 months. There were 66% excellent and good results, 25% of moderate results and 9% of poor results. Due to the difficulty of surgery of neglected lesions, the authors report their experience and emphasize the importance of the initial diagnosis.

The theatre: an effective tool for health promotion

In Africa and in North America, in both rural and urban settings, theatre can be an effective means of health promotion. Projects on women's health, care for patients with mental disorders, and AIDS prevention show the usefulness of this medium for community action programmes.

[The territorial dimension of Quebec's international immigration]

"This paper is devoted to the spatial distribution of Quebec's international immigrants, and to the main territorial stakes related to this type of migration. After analysing international immigration as a flow (distribution of the cohorts of immigrants who entered Quebec during a given period) as well as a stock (distribution of all immigrants surviving in Quebec and their redistribution through internal migration), a critical analysis of the territorial stakes as defined by various agents (active at different levels) is proposed." (SUMMARY IN ENG)