Musculoskeletal ultrasound for 3D bone modeling: A preliminary study applied to lumbar vertebra.

BACKGROUND: There is no non-invasive in vivo method to assess intervertebral kinematics. Current kinematics models are based on in vitro bone reconstructions from computed tomography (CT)-scan imaging, fluoroscopy and MRIs, which are either expensive or deleterious for human tissues. Musculoskeletal ultrasound is an accessible, easy to use and cost-effective device that allows high-resolution, real-time imaging of bone structure. OBJECTIVE: The aim of this preliminary study was to compare the concordance of 3D bone modeling of lumbar vertebrae between CT-scan and ultrasound imaging and to study the intra and inter-reliability of distances measured on 3D ultrasound bone models. METHODS: CT-scan, ultrasound, and in situ data of five lumbar vertebrae from the same human specimen were used. All vertebrae were scanned by tomography and a new musculoskeletal ultrasound procedure. Then, 3D bone modeling was created from both CT-scan and ultrasound image data set. Distances between anatomical bones landmarks were measured on the 3D models and compared to in situ measurements.

Multi-microscopy nanoscale characterization of the doping profile in a hybrid Mg/Ge-doped tunnel junction.

A multi-microscopy investigation of a GaN tunnel junction (TJ) grown on an InGaN-based light emitting diode (LED) has been performed. The TJ consists of a heavily Ge-doped n-type GaN layer grown by ammonia-based molecular-beam epitaxy on a heavily Mg-doped p-type GaN thin layer, grown by metalorganic vapor phase epitaxy. A correlation of atom probe tomography, electron holography and secondary ion mass spectrometry has been performed in order to investigate the nm-scale distribution of both Mg and Ge at the TJ. Experimental results reveal that Mg segregates at the TJ interface, and diffuses into the Ge-doped layer. As a result, the dopant concentration and distribution differ significantly from the nominal values. Despite this, electron holography reveals a TJ depletion width of ∼7 nm, in agreement with band diagram simulations using the experimentally determined dopant distribution.

Meanings and feelings of (Im)mobility in later life: Case study insights from a 'New Mobilities' perspective.

Understandings of mobility and immobility shape research and responses to late life. Yet, the underlying assumptions about mobility often remain fixed on ideas of function and physical ability. The 'new mobilities' paradigm shifts this analysis by focusing on the importance and experience of mobility as a thing in itself rather than a means to an end, and to the complex enactments that operate across a range of relationships, settings, sites, and contexts. This paper provides insight from an embedded case study method comprised of fifteen exploratory interviews with older people at three social locations, including 5 individuals considered 'frail', 5 people who are aging with a disability, and 5 older people who self-identify as 'active'. Considered together and in contrast, the findings from these three distinct but related embedded case sites, viewed from a 'new mobilities' perspective, can help to understand (im)mobility as an embodied experience that is situated within and across social and political contexts, and can explicate how relations of power enhance the mobility of some, and the immobility of others. We conclude that the 'new mobilities' approach introduces ideas to overcome limitations of distance, movement, and place, and in doing so, serves to redefine what it means to be mobile while aging.

[Screening for familial hypercholesterolemia from low-density lipoprotein cholesterol levels at admission in the coronary care unit]. / Dépistage de l'hypercholestérolémie familiale à partir du LDL cholestérol à l'admission en unité de soins intensifs cardiologiques.

BACKGROUND: Familial hypercholesterolemia (FH) is a frequent genetic disorder that leads to premature atherosclerosis and coronary artery disease. However, knowledge of FH by cardiologists is weak, and FH remains underdiagnosed in France. FH should be suspected when low-density lipoprotein cholesterol (LDLc) levels exceed 1.9g/L (4.9mmol/L) without lipid lowering therapy. PURPOSE: This multicenter retro- and prospective observational study aimed at estimating the prevalence of high LDLc levels in patients admitted in coronary care units, and the impact for the personal and familial follow-up for lipid status. METHODS: Retrospective analysis of all plasma lipid measurements performed at admission in coronary care unit of 4 hospitals in 2017. Retrospective analyses of demographic, clinical, and coronary data of consecutive patients with LDLc levels≥1.9g/L. Prospective 1 year follow-up focused on lipid levels, treatments, and personal and familial screening for FH. RESULTS: Lipid measurement has been performed in 2172 consecutive patients, and 108 (5%) had LDLc level≥1.9g/L (mean age 64±14 years, men 51%). The primary cause of the hospitalisation was acute coronary syndrome (78%), and 22% of patients were free off coronary artery disease. Lipid lowering therapy was present in 9% of patients at admission, and 84% at discharge, with high statins regimen. At 1-year follow-up, control of LDLc level was not performed in 20% of patients, and statin dose was decreased (36%) or withdrawn (7%) in 43%. Lipid measurement has been performed in at least one first degree relative in 37% of patients, and genetic exploration has been done for 3 patients. CONCLUSIONS: Screening of FH in CCU should be routinely performed using the Dutch Score when LDLc is above 1.9g/L. Individual and familial management of patients at high risk for FH screened in CCU should be optimized, both for diagnosis and therapeutic purposes.

Interfacial chemistry in a ZnTe/CdSe superlattice studied by atom probe tomography and transmission electron microscopy strain measurements.

The atomic scale analysis of a ZnTe/CdSe superlattice grown by molecular beam epitaxy is reported using atom probe tomography and strain measurements from high-resolution scanning transmission electron microscopy images. CdTe interfaces were grown by atomic layer epitaxy to prevent the spontaneous formation of ZnSe bonds. Both interfaces between ZnTe and CdSe are composed of alloyed layers of ZnSe. Pure CdTe interfaces are not observed and Zn atoms are also visible in the CdSe layers. This information is critical to design superlattices with the expected optoelectronic properties.

3D analysis of advanced nano-devices using electron and atom probe tomography.

The structural and chemical properties of advanced nano-devices with a three-dimensional (3D) architecture have been studied at the nanometre scale. An original method has been used to characterize gate-all-around and tri-gate silicon nanowire transistor by combining electron tomography and atom probe tomography (APT). Results show that electron tomography is a well suited method to determine the morphological structure and the dimension variations of devices provided that the atomic number contrast is sufficient but without an absolute chemical identification. APT can map the 3D chemical distribution of the atoms in devices but suffers from strong distortions in the dimensions of the reconstructed volume. These may be corrected using a simple method based on atomic density correction and electron tomography data. Moreover, this combination is particularly useful in helping to understand the evaporation mechanisms and improve APT reconstructions. This paper demonstrated that a full 3D characterization of nano-devices requires the combination of both tomography techniques.

Specifications for hard condensed matter specimens for three-dimensional high-resolution tomographies.

Tomography is a standard and invaluable technique that covers a large range of length scales. It gives access to the inner morphology of specimens and to the three-dimensional (3D) distribution of physical quantities such as elemental composition, crystalline phases, oxidation state, or strain. These data are necessary to determine the effective properties of investigated heterogeneous media. However, each tomographic technique relies on severe sampling conditions and physical principles that require the sample to be adequately shaped. For that purpose, a wide range of sample preparation techniques is used, including mechanical machining, polishing, sawing, ion milling, or chemical techniques. Here, we focus on the basics of tomography that justify such advanced sample preparation, before reviewing and illustrating the main techniques. Performances and limits are highlighted, and we identify the best preparation technique for a particular tomographic scale and application. The targeted tomography techniques include hard X-ray micro- and nanotomography, electron nanotomography, and atom probe tomography. The article mainly focuses on hard condensed matter, including porous materials, alloys, and microelectronics applications, but also includes, to a lesser extent, biological considerations.

Structural and optical properties of InGaN/GaN nanowire heterostructures grown by PA-MBE.

The structural and optical properties of InGaN/GaN nanowire heterostructures grown by plasma-assisted molecular beam epitaxy have been studied using a combination of transmission electron microscopy, electron tomography and photoluminescence spectroscopy. It is found that, depending on In content, the strain relaxation of InGaN may be elastic or plastic. Elastic relaxation results in a pronounced radial In content gradient. Plastic relaxation is associated with the formation of misfit dislocations at the InGaN/GaN interface or with cracks in the InGaN nanowire section. In all cases, a GaN shell was formed around the InGaN core, which is assigned to differences in In and Ga diffusion mean free paths.

[Hopes for future practice of junior orthopedic surgeons in France: a sociological study]. / Aspirations et exercice professionnel futur des jeunes orthopédistes français.

Medical demographics have become a major public health issue in France since the publication of the Berlan report in 2002 which announced an upcoming shortage in the next 20 years. But demographic projections cannot be limited to an accounting of training and retirement figures. Other factors such as demographic distribution, changing societal aspirations (free time), modes and sites of occupational activities, the influence of feminization, and initial training and its effects on professional practice must be taken into consideration. The purpose of this work was to study these parameters in orthopedic and traumatology surgery. This was a sociological study designed to ascertain the aspirations of junior orthopedic surgeons. Forty-seven interns in orthopedic surgery in the Paris area were invited to complete a questionnaire in March 2003. Forty-two responded. The choice of orthopedics was an intellectual choice. The attractiveness of the specialty was particularly important during the final years of medical school. Fewer junior surgeons would rather practice in a university hospital setting, more preferring a mixed setting with a private (fees) and a public (salary) component. The desire for "free time" was particularly important. Fewer juniors wanted to practice in general hospitals. For orthopedic surgeons, private practice and payment by fees are the cornerstones of medical practice.

Assessment by MRI of local porosity in dough during proving. theoretical considerations and experimental validation using a spin-echo sequence.

Proving is a key stage in the development of the final structure of bread, as invasive measurements may provoke dough collapse. Therefore, better understanding and better control of the nucleation and the growth of bubbles require the development of non-invasive methods of measurement. In the present work, a non-invasive method is presented for the measurement of local dough porosity from MR image analysis. For this, a direct relation between the gray level of a voxel and its gas fraction was established in the absence of heat and mass transfer. At whole dough scale for a one-dimensional expansion, the porosity estimated from the gray level was compared with the porosity estimated from total dough volume measurements in a range of [0.10, 0.74 m(3) of gas/m(3) of dough]. For short proving times (<30 min), MR image analysis underestimated porosity by a maximum of 0.03 m(3) of gas/m(3) of dough, but otherwise the difference between the two means of measurement was within the standard error of total dough measurements (+/-0.01 m(3) of gas/m(3) of dough). Maps of local porosity in dough during proving are also presented and discussed.

[1998 Quebec Social and Health Survey: determinants of chronic respiratory diseases]. / Enquête sociale et de santé de 1998 au Québec: divers déterminants des maladies chroniques respiratoires.

In the course of the "1998 Health and Social Survey", questions were included to verify the prevalence of chronic respiratory diseases and also of wheezing. The objectives of this study were 1) to verify the prevalence of wheezing and its validity as an indicator of chronic respiratory diseases in Québec; and 2) to examine the relationship between chronic respiratory diseases and some of their potential determinants. A total of 30,386 individuals participated in the study. For all ages, the prevalence of wheezing was 5.4%. It was associated with asthma, allergies, chronic bronchitis and emphysema. A low familial income and tobacco smoking were associated with wheezing, asthma, chronic bronchitis and emphysema. Passive smoking was associated with wheezing whereas the presence of carpets was associated with wheezing and asthma. Between 32 and 48% of families with an asthmatic or an allergic member modified their dwelling to alleviate respiratory problems. The prevalence of wheezing documented here was lower than in anglosaxon countries. This result could be explained by a cultural factor (the French translation or the perception of wheezing). This study emphasizes the role of reducing tobacco smoking in the prevention of chronic respiratory diseases.

Oncostatin M production by blood and alveolar neutrophils during acute lung injury.

Polymorphonuclear neutrophils (PMN) are involved in the pathogenesis of acute lung injury (ALI), secreting numerous mediators such as proteases, reactive oxygen species, and cytokines. Because we had recently observed the ability of normal human PMN to degranulate and synthesize oncostatin M (OSM), an IL-6-family cytokine, we quantified OSM production ex vivo by highly purified blood and alveolar PMN from 24 ventilated patients with ALI, including some patients with severe pneumonia. Most of the patients had no detectable OSM in plasma, and OSM production by cultured blood PMN was similar to that of healthy controls. However, OSM was present in bronchoalveolar lavage (BAL) fluid supernatant, with significantly higher levels during pneumonia. In addition, alveolar OSM levels correlated with the number of PMN obtained by BAL, suggesting that PMN are an important source of OSM within the alveoli. Indeed, purified alveolar PMN from all of the patients, especially those with pneumonia, strongly produced OSM. Interestingly, in the latter patients, alveolar PMN always produced more OSM than autologous blood PMN. These results document the functional duality of PMN in ALI by showing the participation of PMN in the modulation of lung inflammation.

Four intracellular genomes direct weevil biology: nuclear, mitochondrial, principal endosymbiont, and Wolbachia.

Cell physiology in the weevil Sitophilus oryzae is coordinated by three integrated genomes: nuclear, mitochondrial, and the "S. oryzae principal endosymbiont" (SOPE). SOPE, a cytoplasmic bacterium (2 x 10(3) bacteria per specialized bacteriocyte cell and 3 x 10(6) bacteria per weevil) that belongs to the proteobacteria gamma3-subgroup, is present in all weevils studied. We discovered a fourth prokaryotic genome in somatic and germ tissues of 57% of weevil strains of three species, S. oryzae, Sitophilus zeamais, and Sitophilus granarius, distributed worldwide. We assigned this Gram-negative prokaryote to the Wolbachia group (alpha-proteobacteria), on the basis of 16S rDNA sequence and fluorescence in situ DNA-RNA hybridization (FISH). Both bacteria, SOPE and Wolbachia, were selectively eliminated by combined heat and antibiotic treatments. Study of bacteria involvement in this insect's genetics and physiology revealed that SOPE, which induces the specific differentiation of the bacteriocytes, increases mitochondrial oxidative phosphorylation through the supply of pantothenic acid and riboflavin. Elimination of this gamma3-proteobacterium impairs many physiological traits. By contrast, neither the presence nor the absence of Wolbachia significantly affects the weevil's physiology. Wolbachia, disseminated throughout the body cells, is in particularly high density in the germ cells, where it causes nucleocytoplasmic incompatibility. The coexistence of two distinct types of intracellular proteobacteria at different levels of symbiont integration in insects illustrates the genetic complexity of animal tissue. Furthermore, evolutionary timing can be inferred: first nucleocytoplasm, then mitochondria, then SOPE, and finally Wolbachia. Symbiogenesis, the genetic integration of long-term associated members of different species, in the weevil appears to be a mechanism of speciation (with Wolbachia) and provides a means for animals to acquire new genes that permit better adaptation to the environment (with SOPE).

Oncostatin M production and regulation by human polymorphonuclear neutrophils.

Oncostatin M (OSM) is an interleukin-6 (IL-6) family cytokine known in particular to induce the synthesis of acute-phase proteins by hepatocytes. Because human polymorphonuclear neutrophils (PMN) can secrete numerous cytokines, the potential production of OSM by PMN was investigated. Highly purified PMN were found to contain an intracellular stock of preformed OSM that was rapidly mobilized by degranulating agents such as phorbol myristate acetate and granulocyte-macrophage colony-stimulating factor (GM-CSF). Moreover, PMN produced OSM after a few hours of stimulation by various agonists. The most potent effect was observed with the combination of lipopolysaccharide and GM-CSF, which had a concentration- and time-dependent effect at both the protein and mRNA levels. Actinomycin D strongly reduced OSM mRNA induction, suggesting the involvement of gene transcription. Cycloheximide inhibited OSM protein synthesis but did not affect the release of preformed stores. In addition, OSM production was downregulated by dexamethasone, whereas IL-10 had no effect. The OSM produced by PMN was biologically active, as demonstrated by its ability to induce alpha1-acid glycoprotein synthesis by HepG2 cells. OSM secretion thus occurs through a two-step mechanism in PMN, consisting of early release of a preformed stock, followed by de novo protein synthesis. This would allow rapid and sustained OSM release to occur at inflammatory sites, and may contribute to the modulation of local inflammation.

Simple epithelium keratins are required for maintenance of hepatocyte integrity.

Keratin 8 (K8)-deficient adult mice develop a severe disease of the gastrointestinal tract characterized mainly by colorectal hyperplasia and inflammation. Given that hepatocytes contain K8/K18 heteropolymers only, this animal model was used to assess the contribution of these simple epithelium keratins to hepatocyte structural and functional integrity. Homozygous mutant (HMZ), heterozygous, and wild-type (WT) mice were examined for hepatocyte structural and metabolic features and their survival to partial hepatectomy. Except for the presence of few necrotic foci, no other tissular or cellular alterations were observed in nonhepatectomized HMZ mouse livers; glycogen and lipid peroxidation levels were essentially normal, but a small reduction in bile flow was observed. In response to a single pentobarbital injection, HMZ mice had longer sleeping times than heterozygous and WT mice. After a two-thirds partial hepatectomy under pentobarbital anesthesia, all HMZ mice died within a few hours, whereas those anesthetized with ether survived for 1 to 2 days. One hour after hepatectomy after pentobarbital anesthesia, many hepatocytes contained erythrocytes and large vacuoles in the cytoplasm, which suggests damage at the plasma membrane level in response to a sudden increase in portal blood flow. In line with these findings, an uptake of trypan blue by HMZ but not WT mouse hepatocytes was observed during a 10 ml/minute perfusion via the portal vein with a dye-supplemented buffer. Subsequent cellular dispersion led to viable WT mouse hepatocytes but largely nonviable HMZ mouse hepatocytes. Better viability was obtained at lower perfusion rates. Partially hepatectomized heterozygous mice developed liver steatosis, a condition that was not associated with a change in K8 content but perhaps linked to the presence of the neo gene. Transgenic HMZ mouse rescue experiments with a full-length K8 gene confirmed that the phenotypic alterations observed in partially hepatectomized HMZ mice were caused by the disruption of the K8 gene. Taken together, these findings demonstrate that simple epithelium keratins are essential for the maintenance of hepatocyte structural and functional integrity.

A case of tyrosinaemia type I with normal level of succinylacetone in the amniotic fluid.

Prenatal diagnosis of tyrosinaemia type I can be achieved in cultured amniotic cells and in chorionic villus material by testing the activity of fumarylacetoacetate hydrolase and by DNA analysis, and in amniotic fluid by succinylacetone measurement. This specific metabolite can be measured either by gas chromatography-mass spectrometry or by delta-aminolevulinate dehydratase inhibition assay. In a series of 65 at-risk cases tested with the enzyme inhibition assay, one case out of the 18 with the disease had a normal level of succinylacetone. This case is presented.

[Complementary neuromotor examination of infants at risk for sequelae.Why? How?]. / Examen neuromoteur complémentaire des nourrissons à risque de séquelles. Pourquoi? Comment?

In many cases the traditional neurological examination of high risk newborns for neurological problems secondary to perinatal difficulties does not identify easily the absence or the presence of cerebral palsy before walking. To help the neuromoteur follow up in these children, the authors suggest a complementary neuromotor examination that is successful only in normal infants. This examination is done in front of a mirror in the presence of the parents in order to increase the attention of the child, whose participation is necessary for a successful examination. Two motor responses are evaluated: the lateral support on, alternately, right and left superior limbs, and the lateral abduction reaction of the hip of each limb. When normal these two motor responses allow an early affirmation of integrity of motor paths if the examination is performed under carefully controlled conditions.