Kinematic features of whole-body reaching movements underwater: Neutral buoyancy effects

Astronauts' training is conventionally performed in a pool to reproduce weightlessness by exploiting buoyancy which is supposed to reduce the impact of gravity on the body. However, this training method has not been scientifically validated yet, and requires first to study the effects of underwater exposure on motor behavior. We examined the influence of neutral buoyancy on kinematic features of whole-body reaching underwater and compared them with those produced on land. Eight professional divers were asked to perform arm reaching movements toward visual targets while standing. Targets were presented either close or far from the subjects (requiring in the latter case an additional whole-body displacement). Reaching movements were performed on land or underwater in two different contexts of buoyancy. The divers either wore a diving suit only with neutral buoyancy applied to their center of mass or were additionally equipped with a submersible simulated space suit with neutral buoyancy applied to their body limbs. Results showed that underwater exposure impacted basic movement features, especially movement speed which was reduced. However, movement kinematics also differed according to the way buoyancy was exerted on the whole-body. When neutral buoyancy was applied to the center of mass only, some focal and postural components of whole-body reaching remained close to land observations, notably when considering the relative deceleration duration of arm elevation and concomitant forward trunk bending when reaching the far target. On the contrary, when neutral buoyancy was exerted on body segments, movement kinematics were close to those reported in weightlessness, as reflected by the arm deceleration phase and the whole-body forward displacement when reaching the far target. These results suggest that astronauts could benefit from the application of neutral buoyancy across the whole-body segments to optimize underwater training and acquire specific motor skills which will be used in space.

Glycidyl alkoxysilane reactivities towards simple nucleophiles in organic media for improved molecular structure definition in hybrid materials

We report the first comprehensive study of the reactivity in organic media of (3-glycidyloxypropyl)trialkoxysilanes towards common nucleophiles. Their reactivity have to be emphasized in order to design and to improve new sol–gel hybrid synthesis.

Vascular imaging with contrast agent in hard and soft tissues using microcomputed-tomography

Vascularization is essential for many tissues and is a main requisite for various tissue-engineering strategies. Different techniques are used for highlighting vasculature, in vivo and ex vivo, in 2-D or 3-D including histological staining, immunohistochemistry, radiography, angiography, microscopy, computed tomography (CT) or micro-CT, both stand-alone and synchrotron system. Vascularization can be studied with or without a contrast agent. This paper presents the results obtained with the latest Skyscan micro-CT (Skyscan 1272, Bruker, Belgium) following barium sulphate injection replacing the bloodstream in comparison with results obtained with a Skyscan In Vivo 1076. Different hard and soft tissues were perfused with contrast agent and were harvested. Samples were analysed using both forms of micro-CT, and improved results were shown using this new micro-CT. This study highlights the vasculature using micro-CT methods. The results obtained with the Skyscan 1272 are clearly defined compared to results obtained with Skyscan 1076. In particular, this instrument highlights the high number of small vessels, which were not seen before at lower resolution. This new micro-CT opens broader possibilities in detection and characterization of the 3-D vascular tree to assess vascular tissue engineering strategies.

[Mental changes in women due to the use of hormonal contraception]

The study investigates physical, mental and sexual changes in women at the beginning of use or after discontinuation of a combined hormonal contraception. Thirty women were interviewed at least 3 months and at most 2 years after the start of use or discontinuation of combined hormonal contraception. Semi-structured interviews were supplemented by 16-symptom rating scale on which women assessed the results of an imaginary study of side effects of hormonal contraception. Both methods identically demonstrated pronounced effect of combined hormonal contraception on decline in sexual desire and painful menstruation. No clear difference was found in psychical symptoms, although qualitative analysis indicated possible changes.

Direct comparison of current cell-based and cell-free approaches towards the repair of craniofacial bone defects - A preclinical study

For craniofacial bone defect repair, several alternatives to bone graft (BG) exist, including the combination of biphasic calcium phosphate (BCP) biomaterials with total bone marrow (TBM) and bone marrow-derived mesenchymal stromal cells (MSCs), or the use of growth factors like recombinant human bone morphogenic protein-2 (RhBMP-2) and various scaffolds. Therefore, clinicians might be unsure as to which approach will offer their patients the most benefit. Here, we aimed to compare different clinically relevant bone tissue engineering methods in an "all-in-one" study in rat calvarial defects. TBM, and MSCs committed or not, and cultured in two- or three-dimensions were mixed with BCP and implanted in bilateral parietal bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant de novo bone formation was observed in rhBMP-2 and BG groups, and in a lesser amount, when BCP biomaterials were mixed with TBM or committed MSCs cultured in three-dimensions. Due to the efficacy and safety of the TBM/BCP combination approach, we recommend this one-step procedure for further clinical investigation.

STATEMENT OF SIGNIFICANCE

For craniofacial repair, total bone marrow (BM) and BM mesenchymal stem cell (MSC)-based regenerative medicine have shown to be promising in alternative to bone grafting (BG). Therefore, clinicians might be unsure as to which approach will offer the most benefit. Here, BM and MSCs committed or not were mixed with calcium phosphate ceramics (CaP) and implanted in bone defects in rats. RhBMP-2 and BG were used as positive controls. After 7 weeks, significant bone formation was observed in rhBMP-2 and BG groups, and when CaP were mixed with BM or committed MSCs. Since the BM-based procedure does not require bone harvest or cell culture, but provides de novo bone formation, we recommend consideration of this strategy for craniofacial applications.

Production of hyperpolarized H_{2} molecules from H[over →] atoms in gas-storage cells

The preservation of the nuclear polarization of hydrogen atoms during the recombination to molecules was observed on different surface materials in the temperature range from 45 to 100 K and for magnetic fields up to 1 T. On a gold and a fused quartz surface, the expected molecular polarization of about 50% or lower of the atomic polarization was measured, while a surface layer of perfluoropolyether (Fomblin) shows a nearly complete preservation (at least 97%) of the atomic polarization during the recombination process. Further experiments have the possibility of storing polarized deuterium molecules and to use them in nuclear-fusion installations. Another application might be the production of polarized substances for enhanced NMR techniques.

Enriching a cellulose hydrogel with a biologically active marine exopolysaccharide for cell-based cartilage engineering

The development of biologically and mechanically competent hydrogels is a prerequisite in cartilage engineering. We recently demonstrated that a marine exopolysaccharide, GY785, stimulates the in vitro chondrogenesis of adipose stromal cells. In the present study, we thus hypothesized that enriching our silated hydroxypropyl methylcellulose hydrogel (Si-HPMC) with GY785 might offer new prospects in the development of scaffolds for cartilage regeneration. The interaction properties of GY785 with growth factors was tested by surface plasmon resonance (SPR). The biocompatibility of Si-HPMC/GY785 towards rabbit articular chondrocytes (RACs) and its ability to maintain and recover a chondrocytic phenotype were then evaluated in vitro by MTS assay, cell counting and qRT-PCR. Finally, we evaluated the potential of Si-HPMC/GY785 associated with RACs to form cartilaginous tissue in vivo by transplantation into the subcutis of nude mice for 3 weeks. Our SPR data indicated that GY785 was able to physically interact with BMP-2 and TGFβ. Our analyses also showed that three-dimensionally (3D)-cultured RACs into Si-HPMC/GY785 strongly expressed type II collagen (COL2) and aggrecan transcripts when compared to Si-HPMC alone. In addition, RACs also produced large amounts of extracellular matrix (ECM) containing glycosaminoglycans (GAG) and COL2. When dedifferentiated RACs were replaced in 3D in Si-HPMC/GY785, the expressions of COL2 and aggrecan transcripts were recovered and that of type I collagen decreased. Immunohistological analyses of Si-HPMC/GY785 constructs transplanted into nude mice revealed the production of a cartilage-like extracellular matrix (ECM) containing high amounts of GAG and COL2. These results indicate that GY785-enriched Si-HPMC appears to be a promising hydrogel for cartilage tissue engineering. Copyright © 2015 John Wiley & Sons, Ltd.

Sensitivity of ultracold atoms to quantized flux in a superconducting ring

We report on the magnetic trapping of an ultracold ensemble of (87)Rb atoms close to a superconducting ring prepared in different states of quantized magnetic flux. The niobium ring of 10  μm radius is prepared in a flux state n Φ(0), where Φ(0)=h/2e is the flux quantum and n varying between ±6. An atomic cloud of 250 nK temperature is positioned with a harmonic magnetic trapping potential at ∼18  μm distance below the ring. The inhomogeneous magnetic field of the supercurrent in the ring contributes to the magnetic trapping potential of the cloud. The induced deformation of the magnetic trap impacts the shape of the cloud, the number of trapped atoms, as well as the center-of-mass oscillation frequency of Bose-Einstein condensates. When the field applied during cooldown of the chip is varied, the change of these properties shows discrete steps that quantitatively match flux quantization.

Evaluation of new bone formation in irradiated areas using association of mesenchymal stem cells and total fresh bone marrow mixed with calcium phosphate scaffold

The consequences of the treatment of the squamous cell carcinomas of the upper aerodigestive tract (bone removal and external radiation therapy) are constant. Tissue engineering using biphasic calcium phosphate (BCP) and mesenchymal stem cells (MSC) is considered as a promising alternative. We previously demonstrated the efficacy of BCP and total fresh bone marrow (TBM) in regenerating irradiated bone defect. The aim of this study was to know if adding MSC to BCP + TBM mixture could improve the bone formation in irradiated bone defects. Twenty-four Lewis 1A rats received a single dose of 20 Gy to the hind limbs. MSC were sampled from non-irradiated donors and amplified in proliferative, and a part in osteogenic, medium. 3 weeks after, defects were created on femurs and tibias, which were filled with BCP alone, BCP + TBM, BCP + TBM + uncommitted MSC, or BCP + TBM + committed MSC. 3 weeks after, samples were removed and prepared for qualitative and quantitative analysis. The rate of bone ingrowth was significantly higher after implantation of BCP + TBM mixture. The adding of a high concentration of MSC, committed or not, didn't improve the bone regeneration. The association BCP + TBM remains the most efficient material for bone substitution in irradiated areas.

Contribución al estudio de la Bartonella Muris

1921 E. Mayer del Instituto Tropical de Hamburgo, estudiando la acción del "Bayer 0205" sobre ratas infectadas experimentalmente con tripanosoma Rhodesiense, observó la presencia de elementos en los glóbulos rojos, cuya morfología juzgó bastante semejante a la de la Bartonella bacilliformis agente etiológico de la verruga peruana.

Association between right ventricular dysfunction and restrictive lung disease in childhood cancer survivors as measured by quantitative echocardiography

BACKGROUND

Restrictive lung disease is a complication in childhood cancer survivors who received lung-toxic chemotherapy and/or thoracic radiation. Left ventricular dysfunction is documented in these survivors, but less is known about right ventricular (RV) function. Quantitative echocardiography may help detect subclinical RV dysfunction. The aim of this study was to assess RV function quantitatively in childhood cancer survivors after lung-toxic therapy.

PROCEDURES

We identified records of 33 childhood cancer survivors who (1) were treated with lung-toxic therapy and/or radiation, (2) were cancer-free for ≥ one year after therapy, and (3) had pulmonary function tests and echocardiograms from their most recent follow-up visit.

RESULTS

Participants' mean age was 11.6 ± 4.5 years at cancer diagnosis and 23 ± 8.6 years at evaluation. The most common diagnosis was lymphoma/leukemia (n = 27). Twenty-nine subjects had anthracycline exposure. Eleven of the 33 subjects demonstrated restrictive pulmonary impairment (total lung capacity 3.69 ± 1.5 L [69.3 ± 22.4% predicted]). Among quantitative measures of RV function, isovolumetric acceleration (IVA), a measure of contractility, was significantly lower in the group with restrictive lung disease (2.42 ± 0.56 vs. 1.83 ± 0.78 m/sec(2); P < 0.05). There was a trend towards lower tissue Doppler derived S' and tricuspid annular plane systolic excursion in the group with restrictive lung disease. Subjects with restrictive lung disease were found to have ≥ 2 abnormal parameters (P < 0.01).

CONCLUSION

IVA may detect early RV dysfunction in childhood cancer survivors with restrictive lung disease. Our findings require confirmation in a larger study population and validation by cardiac MRI.

Osteoinduction of biphasic calcium phosphate scaffolds in a nude mouse model

Bioceramics combined with isolated stem cells, or with total bone marrow, constitute the main strategies under consideration in the field of bone tissue engineering. In the present preclinical study, two biphasic calcium phosphate scaffolds currently on the market, MBCP® and MBCP+®, with different hydroxyapatite/β-tricalcium phosphate ratio, were implanted ectopically in a nude mouse model. These scaffolds were supplemented either with human mesenchymal stromal cells, or with human total bone marrow, or rat total bone marrow. Biomaterials alone were found to have potentially low, but non-zero, osteoinductive properties, while biomaterials associated with total bone marrow consistently improved osteoinduction in comparison with high concentrations of isolated human stromal cells.

Effect of vitamin D-binding protein genotype on the development of asthma in children

BACKGROUND

Potential vitamin D-related influences on inflammatory diseases such as asthma are controversial, including the suggestion that vitamin D insufficiency is associated with increased asthma morbidity. Vitamin D-binding protein transports vitamin D metabolites in the circulation. Single nucleotide polymorphisms in the GC gene encoding vitamin D-binding protein are associated with circulating vitamin D metabolite levels in healthy infants and toddlers.

OBJECTIVE

To test the hypothesis that GC single nucleotide polymorphisms encoding the D432E and T436K variants predict subsequent development of asthma in healthy children.

METHODS

A retrospective medical record review was performed to determine the development of asthma in 776 children in whom GC genotype, vitamin D-binding protein concentration, and circulating 25-hydroxyvitamin D had been determined at 6 to 36 months of age. Demographic and detailed current clinical data were collected and criteria for asthma were recorded.

RESULTS

GC genotype was available for 463 subjects. After an initial analysis of all subject data, the analysis was limited to the predominant Hispanic population (72.1%) to minimize potential confounding effects of ethnicity. Asthma was diagnosed in 87 children (26%). Subjects with the GC genotype encoding the ET/ET (Gc1s/Gc1s) variant had lower odds of developing asthma, representing a protective effect compared with subjects with the DT/DT (Gc1f/Gc1f) variant.

CONCLUSION

In the Hispanic population of inner-city New Haven, Connecticut, the ET/ET (Gc1s/Gc1s) genotype of vitamin D-binding protein might confer protection against the development of asthma compared with the wild-type genotype DT/DT (Gc1f/Gc1f).

On variant strategies to solve the magnitude least squares optimization problem in parallel transmission pulse design and under strict SAR and power constraints

Parallel transmission is a very promising candidate technology to mitigate the inevitable radio-frequency (RF) field inhomogeneity in magnetic resonance imaging at ultra-high field. For the first few years, pulse design utilizing this technique was expressed as a least squares problem with crude power regularizations aimed at controlling the specific absorption rate (SAR), hence the patient safety. This approach being suboptimal for many applications sensitive mostly to the magnitude of the spin excitation, and not its phase, the magnitude least squares (MLS) problem then was first formulated in 2007. Despite its importance and the availability of other powerful numerical optimization methods, the MLS problem yet has been faced almost exclusively by the pulse designer with the so-called variable exchange method. In this paper, we investigate various two-stage strategies consisting of different initializations and nonlinear programming approaches, and incorporate directly the strict SAR and hardware constraints. Several schemes such as sequential quadratic programming, interior point methods, semidefinite programming and magnitude squared least squares relaxations are studied both in the small and large tip angle regimes with RF and static field maps obtained in vivo on a human brain at 7T. Convergence and robustness of the different approaches are analyzed, and recommendations to tackle this specific problem are finally given. Small tip angle and inversion pulses are returned in a few seconds and in under a minute respectively while respecting the constraints, allowing the use of the proposed approach in routine.

Effect of water velocity on hydroponic phytoremediation of metals

The influence of flow velocity on the uptake of cadmium, copper, lead, and zinc by hydroponically grown soft stem bulrush (Scirpus validus) was investigated. The roots of the plants were exposed to a continually recycled, nutrient enriched, synthetic stormwater. Plants were divided into groups and the roots of each group exposed to different but constant water velocities. The metal concentrations in the roots and stems were compared after three weeks. Metal accumulation in roots was increased for water velocities between 1.3 and 4.0 cm s(-1). In a second experiment, the roots of all plants were exposed to a single velocity and the root and stem metal concentrations were determined as a function of time. Metal concentrations in the roots approached a constant value after three weeks. After this time, accumulation of metals depends upon root growth. The results suggest that long-term accumulation by the roots of hydroponic Scirpus validus can be increased by increasing water velocity, which implies that floating islands with movement will retain more metals from the water column.

Exercise-induced bronchoconstriction and vocal cord dysfunction: two sides of the same coin?

Patients are referred often because of self-reported symptoms of dyspnea and wheeze during exercise. The two common causes of exercise-induced dyspnea are exercise-induced bronchoconstriction (EIB) and vocal cord dysfunction (VCD). It can be extraordinarily difficult to differentiate between the two, especially because they may coexist in the same patient. EIB is caused by bronchial smooth muscle constriction in the lower airways due to the inhalation of dry air or allergens during exercise; it is associated with the release of bronchoconstricting mediators from airway cells. EIB can occur in patients with or without persistent asthma. In contrast, VCD is associated with the paradoxical adduction of the vocal cords, especially during inhalation, which may produce inspiratory stridor. VCD can be solitary or comorbid with asthma and/or EIB. EIB classically is most severe after the cessation of exercise, while VCD typically occurs during exercise and resolves quickly upon exercise cessation. However, history is not adequate to differentiate between EIB and VCD, and appropriate challenge tests and flexible laryngoscopy during exercise are often necessary for diagnosis. This article examines our current understanding of these entities and discusses the mechanism, prevalence, diagnosis, and treatment.

[First manifestation of a leucocytoclastic vasculitis in the colon: case report and differential diagnostic aspects]

This report presents a female patient suffering from chronic diarrhea, who developed palpable purpura on the lower extremities 8 weeks after onset of the gastrointestinal symptoms. Biopsies obtained from the colon and skin showed leukocytoclastic vasculitis. Possible triggers or underlying diseases could not be found, and the patient recovered without specific treatment for vasculitis. Possible differential diagnoses and the difficulties in classifying vasculitides are discussed in the present report.

Parkinsonian arm movements as altered by task difficulty

A discrete elbow movement to targets with different indexes of difficulty (ID) was used to determine the kinematic organization of arm movements in a young, an elderly and a Parkinson's disease (PD) group (n = 14). Target size and movement amplitude changes led to expected modifications of the kinematics in all three groups according to Fitts' law. Increased task demands by changing target size produced not only differences between the age-groups, but affected the modulation of velocity and acceleration in the parkinsonian patients differentially. For large amplitude movements, the PD patients were less able to increase velocity and acceleration magnitudes when target accuracy constraints were reduced. These findings, when taken together with the observation that speed scaling was preserved for small movement amplitudes, suggest that a reduced capability to initiate and regulate force is the cause for the observed slowness in PD.

[Pneumatosis intestinalis in anorexia nervosa: a case report]

Pneumatosis intestinalis (PI) is identified as the accumulation of gas within the wall of the small or large intestine. It was first described by Du Vernoi in 1783. The pathogenesis is supposed to be multifactorial. It is assumed that there are 3 paths of disease development: mechanical, bacterial and biochemical. Adult patients are mostly asymptomatic and PI is diagnosed frequently by different radiological methods. The treatment of patients depends on their clinical picture. Most patients can be treated only with antibiotics and elemental diet. In a small number of cases, surgical intervention is essential. We report about a 35-year-old female patient with anorexia nervosa who developed PI after an excessive use of chewing gum for 3 years.