High-precision satellite positioning system as a new tool to study the biomechanics of human locomotion.

New Global Positioning System (GPS) receivers allow now to measure a location on earth at high frequency (5Hz) with a centimetric precision using phase differential positioning method. We studied whether such technique was accurate enough to retrieve basic parameters of human locomotion. Eight subjects walked on an athletics track at four different imposed step frequencies (70-130steps/min) plus a run at free pace. Differential carrier phase localization between a fixed base station and the mobile antenna mounted on the walking person was calculated. In parallel, a triaxial accelerometer, attached to the low back, recorded body accelerations. The different parameters were averaged for 150 consecutive steps of each run for each subject (total of 6000 steps analyzed). We observed a perfect correlation between average step duration measured by accelerometer and by GPS (r=0.9998, N=40). Two important parameters for the calculation of the external work of walking were also analyzed, namely the vertical lift of the trunk and the velocity variation per step. For an average walking speed of 4.0km/h, average vertical lift and velocity variation were, respectively, 4.8cm and 0.60km/h. The average intra-individual step-to-step variability at a constant speed, which includes GPS errors and the biological gait style variation, were found to be 24. 5% (coefficient of variation) for vertical lift and 44.5% for velocity variation. It is concluded that GPS technique can provide useful biomechanical parameters for the analysis of an unlimited number of strides in an unconstrained free-living environment.

Video-assisted thoracoscopic resection of a small pulmonary nodule after computed tomography-guided localization with a hook-wire system. Experience in 45 consecutive patients.

BACKGROUND: This study is a single-institution validation of video-assisted thoracoscopic (VATS) resection of a small solitary pulmonary nodule (SPN) previously localized by a CT-guided hook-wire system in a consecutive series of 45 patients. METHODS: The records of all patients undergoing VATS resection for SPN preoperatively localized by CT-guided a hook-wire system from January 2002 to December 2004 were assessed with respect to failure to localize the lesion by the hook-wire system, conversion thoracotomy rate, duration of operation, postoperative complications, and histology of SPN. RESULTS: Forty-five patients underwent 49 VATS resections, with simultaneous bilateral SPN resection performed in 4. Preoperative CT-guided hook-wire localization failed in two patients (4%). Conversion thoracotomy was necessary in two patients (4%) because it was not possible to resect the lesion by a VATS approach. The average operative time was 50 min. Postoperative complications occurred in 3 patients (6%), one hemothorax and two pneumonia. The mean hospital stay was 5 days (range: 2-18 days). Histological assessment revealed inflammatory disease in 17 patients (38%), metastasis in 17 (38%), non-small-cell lung cancer (NSCLC) in 4 (9%), lymphoma in 3 (6%), interstitial fibrosis in 2 (4%), histiocytoma in one (2%), and hamartoma in one (2%). CONCLUSIONS: Histological analysis of resected SPN revealed unexpected malignant disease in more than 50% of the patients indicating that histological clarification of SPN seems warranted. Video-assisted thoracoscopic resection of SPN previously localized by a CT-guided hook-wire system is related to a low conversion thoracotomy rate, a short operation time, and few postoperative complications, and it is well suited for the clarification of SPN.

Les biothérapies dans le lupus érythémateux disséminé et tes connectivites: nouvelles thérapeutiques [Treatment of connective tissue diseases with biological agents]

As B-cells are crucial for the production of antibodies and also in antigen presentation, they can play an important role in autoimmune connective tissue disease. B-cell surface antigens and receptors which are capable of activating B-cell function have been proposed as targets for therapy in these diseases. Anti-B cell treatments have been used recently in SLE and primary Sjogren's syndrome in a number of open studies, notably anti-CD20 (rituximab), with encouraging results. An anti-BAFF antibody (belimumab) has been tested in patients with SLE and also showed positive results in patients with increased levels of autoantibodies. In contrast, anti-TNF therapy in connective tissue disease and in RA can increase the levels of autoantibodies. Further studies are needed to define the place of these novel treatments in the management of autoimmune connective tissue diseases.

Marqueurs biologiques des statuts vitaminiques B12 et D: aspects analytiques d'importance clinique [Biological markers for the status of vitamins B12 and D: the importance of some analytical aspects in relation to clinical interpretation of results].

Biological markers for the status of vitamins B12 and D: the importance of some analytical aspects in relation to clinical interpretation of results When vitamin B12 deficiency is expressed clinically, the diagnostic performance of total cobalamin is identical to that of holotranscobalamin II. In subclinical B12 deficiency, the two aforementioned markers perform less well. Additional analysis of a second, functional marker (methylmalonate or homocysteine) is recommended. Different analytical approaches for 25-hydroxyvitamin D quantification, the marker of vitamin D deficiency, are not yet standardized. Measurement biases of up to +/- 20% compared with the original method used to establish threshold values are still observed.

Physicochemical and biological characterization of single-walled and double-walled carbon nanotubes in biological media

To study the toxicity of nanoparticles under relevant conditions, it is important to reproducibly disperse nanoparticles in biological media in in vitro and in vivo studies. Here, single-walled nanotubes (SWNTs) and double-walled nanotubes (DWNTs) were physicochemically and biologically characterized when dispersed in phosphate-buffered saline (PBS) and bovine serum albumin (BSA). BSA-SWNT/DWNT interaction resulted in a reduction of aggregation and an increase in particle stabilization. Based on the protein sequence coverage and protein binding results, DWNTs exhibited higher protein binding than SWNTs. SWNT and DWNT suspensions in the presence of BSA increased interleukin-6 (IL-6) levels and reduced tumor necrosis factor-alpha (TNF-α) levels in A549 cells as compared to corresponding samples in the absence of BSA. We next determined the effects of SWNTs and DWNTs on pulmonary protein modification using bronchoalveolar lavage fluid (BALF) as a surrogate collected form BALB/c mice. The BALF proteins bound to SWNTs (13 proteins) and DWNTs (11 proteins), suggesting that these proteins were associated with blood coagulation pathways. Lastly, we demonstrated the importance of physicochemical and biological alterations of SWNTs and DWNTs when dispersed in biological media, since protein binding may result in the misinterpretation of in vitro results and the activation of protein-regulated biological responses.

Chemical and biological properties of phosphorus-fertilized soil under legume and grass cover (Cerrado region, Brazil)

The use of cover crops has been suggested as an effective method to maintain and/or increase the organic matter content, while maintaining and/or enhancing the soil physical, chemical and biological properties. The fertility of Cerrado soils is low and, consequently, phosphorus levels as well. Phosphorus is required at every metabolic stage of the plant, as it plays a role in the processes of protein and energy synthesis and influences the photosynthetic process. This study evaluated the influence of cover crops and phosphorus rates on soil chemical and biological properties after two consecutive years of common bean. The study analyzed an Oxisol in Selvíria (Mato Grosso do Sul, Brazil), in a randomized block, split plot design, in a total of 24 treatments with three replications. The plot treatments consisted of cover crops (millet, pigeon pea, crotalaria, velvet bean, millet + pigeon pea, millet + crotalaria, and millet + velvet bean) and one plot was left fallow. The subplots were represented by phosphorus rates applied as monoammonium phosphate (0, 60 and 90 kg ha-1 P2O5). In August 2011, the soil chemical properties were evaluated (pH, organic matter, phosphorus, potential acidity, cation exchange capacity, and base saturation) as well as biological variables (carbon of released CO2, microbial carbon, metabolic quotient and microbial quotient). After two years of cover crops in rotation with common bean, the cover crop biomass had not altered the soil chemical properties and barely influenced the microbial activity. The biomass production of millet and crotalaria (monoculture or intercropped) was highest. The biological variables were sensitive and responded to increasing phosphorus rates with increases in microbial carbon and reduction of the metabolic quotient.

Chromosome localization of microsatellite markers in the shrews of the Sorex araneus group.

The extremely high rate of karyotypic evolution that characterizes the shrews of the Sorex araneus group makes this group an exceptionally interesting model for population genetics and evolutionary studies. Here, we attempted to map 46 microsatellite markers at the chromosome arm level using flow-sorted chromosomes from three karyotypically different taxa of the Sorex araneus group (S. granarius and the chromosome races Cordon and Novosibirsk of S. araneus). The most likely localizations were provided for 35 markers, among which 25 were each unambiguously mapped to a single locus on the corresponding chromosomes in the three taxa, covering the three sexual chromosomes (XY1Y2) and nine of the 18 autosomal arms of the S. araneus group. The results provide further evidence for a high degree of conservation in genome organization in the S. araneus group despite the presence of numerous Robertsonian rearrangements. These markers can therefore be used to compare the genetic structure among taxa of the S. araneus group at the chromosome level and to study the role of chromosomal rearrangements in the genetic diversification and speciation process of this group.

Genetic removal of tri-unsaturated fatty acids suppresses developmental and molecular phenotypes of an Arabidopsis tocopherol-deficient mutant. Whole-body mapping of malondialdehyde pools in a complex eukaryote.

Malondialdehyde (MDA) is a small, ubiquitous, and potentially toxic aldehyde that is produced in vivo by lipid oxidation and that is able to affect gene expression. Tocopherol deficiency in the vitamin E2 mutant vte2-1 of Arabidopsis thaliana leads to massive lipid oxidation and MDA accumulation shortly after germination. MDA accumulation correlates with a strong visual phenotype (growth reduction, cotyledon bleaching) and aberrant GST1 (glutathione S-transferase 1) expression. We suppressed MDA accumulation in the vte2-1 background by genetically removing tri-unsaturated fatty acids. The resulting quadruple mutant, fad3-2 fad7-2 fad8 vte2-1, did not display the visual phenotype or the aberrant GST1 expression observed in vte2-1. Moreover, cotyledon bleaching in vte2-1 was chemically phenocopied by treatment of wild-type plants with MDA. These data suggest that products of tri-unsaturated fatty acid oxidation underlie the vte2-1 seedling phenotype, including cellular toxicity and gene regulation properties. Generation of the quadruple mutant facilitated the development of an in situ fluorescence assay based on the formation of adducts of MDA with 2-thiobarbituric acid at 37 degrees C. Specificity was verified by measuring pentafluorophenylhydrazine derivatives of MDA and by liquid chromatography analysis of MDA-2-thiobarbituric acid adducts. Potentially applicable to other organisms, this method allowed the localization of MDA pools throughout the body of Arabidopsis and revealed an undiscovered pool of the compound unlikely to be derived from trienoic fatty acids in the vicinity of the root tip quiescent center.

Biological, clinical and population relevance of 95 loci for blood lipids.

Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD.

Localization of HLA-A2.1-restricted T cell epitopes in the circumsporozoite protein of Plasmodium falciparum.

Localization of human MHC class I-restricted T cell epitopes in the circumsporozoite (CS) protein of the human parasite Plasmodium falciparum is an important objective in the development of antimalarial vaccines. To this purpose, we synthesized a series of overlapping synthetic 20-mer peptides, spanning the entire sequence of the 7G8 CS molecule except for the central repeat B cell domain. The P.f.CS peptides were first tested for their ability to bind to the human MHC class I HLA-A2.1 molecule on T2, a human cell line. Subsequently, the use of a series of shorter peptide analogues allowed us to determine the optimal A2.1 binding sequence present in several of the 20-mers. Binding P.f.CS peptides were further tested for their capacity to activate PBL from HLA-A2.1+ immune donors living in a malaria-endemic area. Specific IFN-gamma production was detected in the supernatant of cultures of PBL from exposed individuals. Cytotoxic T cell lines and clones were derived from the PBL of one responder, and their activity was shown to be HLA-A2.1-restricted and specific for the peptide 334-342 of the CS protein. In addition, double transgenic HLA-A2.1 x human beta 2-microglobulin mice were immunized with peptide 1-10 of the CS protein. T cells derived from immune lymph nodes displayed a peptide-specific HLA-A2.1-restricted cytolytic activity after one in vitro stimulation.

Different behaviour of mouse-human chimeric antibody F(ab')2 fragments of IgG1, IgG2 and IgG4 sub-class in vivo.

Mouse-human chimeric monoclonal antibodies (MAbs) of 3 different human IgG sub-classes directed against carcinoembryonic antigen (CEA) have been produced in SP-0 cells transfected with genomic chimeric DNA. F(ab')2 fragments were obtained by pepsin digestion of the purified chimeric MAbs of human IgG1, IgG2 and IgG4 sub-class and of parental mouse MAb IgG1. The 4 F(ab')2 fragments exhibit similar molecular weight by SDS-PAGE. They were labelled with 125I or 131I and high binding (80 to 87%) to purified unsolubilized CEA was observed. In vivo, double labelling experiments indicate that the longest biological half-life and the highest tumour-localization capacity is obtained with F(ab')2 from chimeric MAb of human IgG2 sub-class, whereas F(ab')2 from chimeric MAb IgG4 give very low values for these 2 parameters. F(ab')2 from chimeric MAb IgG1 and from parental mouse MAb yield intermediate results in vivo. Our findings should help to select the appropriate human IgG sub-class to produce chimeric or reshaped MAb F(ab')2 to be used for tumour detection by immunoscintigraphy and for radioimmunotherapy.

Role of biological agents in auto-inflammatory disease in children

BACKGROUND: Biological agents (BA) have recently completed the treatment options in auto-inflammatory diseases (AID) in children with the aim to improve the outcome. TNF-α blocking agents have been the first BA successfully used in children. However, other biological agents targeting cytokines including IL-1 and IL-6 have been shown to be effective (anti-IL-1/6), especially in AID like systemiconset juvenile arthritis (SoJIA) or cryopyrine-associated periodic syndrome (CAPS). In Switzerland, Etanercept has been approved for the treatment of JIA since 2000 and Canakinumab for the treatment of paediatric CAPS since 2009.OBJECTIVES: Evaluation of the use of biological agents in AID in Western Switzerland.METHODS: We selected all patients with AID seen in the Réseau Romand de Rhumatologie Pédiatrique (Lausanne, Geneva, Aigle, Sion, and Neuchâtel) who were treated with the following BA: anti-TNF-α (Etanercept, Infliximab, Adalimumab) and Abatacept, and anti-IL-1/6 (Anakinra, Canakinumab, Tocilizumab). We looked at minor and major adverse events and the activity of the disease before and after treatment with BA and with special regards on anti-IL-1/6.RESULTS: Among 921 children and adolescents followed between 2004 and 2010, we selected 85 patients with AID (PFAPA: 40, FMF: 6, HyperIgD: 1, CAPS: 3, SoJIA: 34). Only patients with CAPS and SoJIA were treated with BA. They had a mean age of 9 years (3-22) and F: M ratio of 1.6:1. 7 patients were treated with one BA, 6 patients with 2 different BAs and 3 with 3 BAs. 3 patients with CAPS were treated with anti-IL-1 and responded very well. 13 SoJIA patients were treated with BA (anti-TNF-α: 8, Abatacept: 1, anti-IL-1/6: 8). 4 patients treated by anti-TNF-α were switched to anti-IL-1/6 because of lack of response to treatment (cf Table 1). We did not have any serious adverse events and no serious infections.CONCLUSIONS: Patients with SoJIA and CAPS clearly benefit from treatment with BA. General tolerance was good. In the CAPS group the response to IL-1 was excellent. In SoJIA, 3/4 patients, switched from anti-TNF-α to anti-IL-1/6 for lack of therapeutic response, did not respond well to the second medication. These patientsseem to represent a population relatively resistant to treatment with BA. Due to the low number of patients in our cohort, the response to BA in SoJIA patients non-responder to anti- TNF-α agents should be further studied.