Experimental characterization and micromechanical modeling of the elastic response of the human humerus under bending impact.

This paper investigates the characterization and numerical modeling of the elastic behavior of the human humerus bone using a recently developed micromechanical approach coupled to nanoindentation measurements. At first, standard three-point bending experiments were conducted under low static loading, using several humerus diaphysis in order to identify the apparent elastic modulus of the bone in static regime. Then, a drop tower impact experiment was used on the same set of humerus diaphysis specimens, in order to assess the elastic modulus in dynamic regime. These measurements will be used as reference bases for comparison purpose. The originality of this work, lies in the coupling between a two-phase micromechanical approach based on Mori-Tanaka homogenization scheme for cylindrical voids and nanoindentation measurements of the elastic modulus of the bone matrix phase. This model has been implemented using a user defined material subroutine VMAT in ABAQUS© Explicit code. The bone mechanical response prediction using the proposed methodology was validated against previous standard experimental data. Finally, it was shown that the numerical predictions are consistent with the physical measurements obtained on human humerus via the good estimation of the ultimate impact load.

Materialism, Financial Motives and Gambling: Examination of an Unexplored Relationship.

Gambling has an inherent structural monetary component, and financial motive is one of the main motivations for gambling. Despite this, and contrary to other addictive behaviours that involve money such as compulsive buying, gambling has never been studied from a materialism perspective. The objective of the present study was to explore the links between materialism and gambling disorder (GD) and whether this relationship is mediated by financial motives for gambling. We compared 65 pathological gamblers (PGs) seeking treatment to 65 matched non-problem gamblers. The data collection included socio-demographics, gambling characteristics, the Materialism Values Scale, the Gambling Motives Questionnaire-Financial, and the Rosenberg Self-Esteem Scale. The statistical analysis included linear mixed models and Structural Equation Modelling. The level of materialism was significantly higher for the PGs, except for the Centrality dimension. Only one mediated effect was significant, and it concerned an indirect path from Happiness through financial motives. Moreover, Happiness explained most of the variance of the probability of becoming a PG. Contrary to compulsive buying, the PGs seemed to display materialism in a more experiential way that was centred on what possessions can induce secondarily rather than on the possessions themselves. The belief that material possessions are essential to achieving happiness may encourage the PG to gamble, thus contributing to both the development and maintenance of GD. We provided evidence that materialism is a key concept in the comprehension of GD and should be further considered when adapting care strategies.

A three-dimensional geometric quantification of human cortical canals using an innovative method with micro-computed tomographic data.

The complex architecture of bone has been investigated for several decades. Some pioneer works proved an existing link between microstructure and external mechanical loading applied on bone. Due to sinuous network of canals and limitations of experimental acquisition technique, there has been little quantitative analysis of three-dimensional description of cortical network. The aim of this study is to provide an algorithmic process, using Python 3.5, in order to identify 3D geometrical characteristics of voids considered as canals. This script is based on micro-computed tomographic slices of two bone samples harvested from the humerus and femur of male cadaveric subject. Slice images are obtained from 2.94 µm isotropic resolution. This study provides a generic method of image processing which considers beam hardening artefact so as to avoid heuristic choice of global threshold value. The novelty of this work is the quantification of numerous three-dimensional canals features, such as orientation or canal length, but also connectivity features, such as opening angle, and the accurate definition of canals as voids which ranges from connectivity to possibly another intersection. The script was applied to one humeral and one femoral samples in order to analyse the difference in architecture between bearing and non-bearing cortical bones. This preliminary study reveals that the femoral specimen is more porous than the humeral one whereas the canal network is denser and more connected.

First full-length sequences of the S gene of European isolates reveal further diversity among turkey coronaviruses.

An increasing incidence of enteric disorders clinically suggestive of the poult enteritis complex has been observed in turkeys in France since 2003. Using a newly designed real-time reverse transcriptase-polymerase chain reaction assay specific for the nucleocapsid (N) gene of infectious bronchitis virus (IBV) and turkey coronaviruses (TCoV), coronaviruses were identified in 37% of the intestinal samples collected from diseased turkey flocks. The full-length spike (S) gene of these viruses was amplified, cloned and sequenced from three samples. The French S sequences shared 98% identity at both the nucleotide and amino acid levels, whereas they were at most 65% and 60% identical with North American (NA) TCoV and at most 50% and 37% identical with IBV at the nucleotide and amino acid levels, respectively. Higher divergence with NA TCoV was observed in the S1-encoding domain. Phylogenetic analysis based on the S gene revealed that the newly detected viruses form a sublineage genetically related with, but significantly different from, NA TCoV. Additionally, the RNA-dependent RNA polymerase gene and the N gene, located on the 5' and 3' sides of the S gene in the coronavirus genome, were partially sequenced. Phylogenetic analysis revealed that both the NA TCoV and French TCoV (Fr TCoV) lineages included some IBV relatives, which were however different in the two lineages. This suggested that different recombination events could have played a role in the evolution of the NA and Fr TCoV. The present results provide the first S sequence for a European TCoV. They reveal extensive genetic variation in TCoV and suggest different evolutionary pathways in North America and Europe.

Molecular diversity of porcine and human isolates of Pasteurella multocida.

AIMS: To examine the variability among Pasteurella multocida strains isolated from pigs (nasal, tonsil and lung specimens) and humans in France. METHODS AND RESULTS: The genetic diversity of 117 French isolates of P. multocida, obtained from pigs (n = 101) and humans (n = 16) and three reference strains, was evaluated by pulsed-field gel electrophoresis (PFGE) after macrorestriction with ApaI. Sixty-four patterns were detected. The genetic relationships revealed five clusters (Aa1, Aa2, Aa3, Ab and B). The pig isolates obtained from pneumonic lungs and nasal cavities were clustered in groups Ab and Aa1, respectively (P < 0.05). Up to four different PFGE patterns were detected in the same farm. Isolates producing dermonecrotic toxins were clustered only in group Aa1, suggesting that the toxigenic isolates were more genetically homogenous than the others. Conversely, cluster Aa3 was significantly associated with human isolates even if the human isolates are spread over most of the clusters. CONCLUSIONS: Pasteurella multocida strains were genetically diverse, but pig and human isolates were significantly clustered in distinct phylogenetic groups. SIGNIFICANCE AND IMPACT OF THE STUDY: The discrimination index was >0.95 in both populations of human and pig isolates. Therefore, ApaI-PFGE seems to be a useful tool for epidemiological tracing of P. multocida infections.

Aluminium hydroxide-induced granulomas in pigs.

The effect of intramuscular injection of 40 mg/2 ml aluminium hydroxide in the neck of pigs was examined in a number of ways. The investigation followed repeated slaughterhouse reports, according to which 64.8% of pigs from one particular farm were found at slaughter to have one or more nodules in the muscles of the neck (group slaughtered). The pigs had been injected with a vaccine containing 40 mg/2 ml dose of aluminium hydroxide as adjuvant. Research consisted of two phases: first, an epidemiological study was carried out, aimed at determining the risk factors for the granulomas. The results indicated that the vaccine was to be held responsible for the formation of granulomas. A clinical trial was then performed to further substantiate the initial hypothesis, by comparing pigs, which were aseptically inoculated twice with either the original vaccine or the adjuvant alone (groups vaccine and adjuvant) to pigs inoculated twice with apyrogenic bi-distilled water (group water) and to pigs inoculated once with the adjuvant and once with apyrogenic bi-distilled water (group adjuvant/water). Both studies agreed in their conclusions, which indicate that the high amount of aluminium hydroxide was the cause of the granulomas.

Antimicrobial susceptibility of Streptococcus suis isolated from swine in France and from humans in different countries between 1996 and 2000.

The susceptibility of 135 Streptococcus suis strains isolated from pigs (n = 110) and from humans (n = 25) to 13 antimicrobial agents was studied by microdilution and disc diffusion methods using Mueller-Hinton Agar II (MH) supplemented with either defibrinated sheep blood (MHSB) or horse serum (MHHS). Results were similar for both methods used except for penicillin G whose zone diameters were reduced with MHSB compared with MHHS. When MH was supplemented with sheep blood, 39% of S. suis strains classified as penicillin susceptible by MHHS microdilution showed intermediate susceptibility. Nearly all strains were susceptible to penicillin G (except by disc diffusion in MHSB), amoxicillin, ceftiofur, florfenicol, gentamicin and bacitracin. The least active antimicrobial agents were doxycycline and macrolides/lincosamides. High-level resistance (MIC > 500 mg/L or zone diameters < 10 mm) to streptomycin and kanamycin was detected in only a few strains. The virulence of strains did not seem to be related to antimicrobial resistance because no statistical difference was reported between the proportion of resistant strains of S. suis isolated from pigs with meningitis, septicaemia and arthritis, and those from tonsils and nasal cavities. However, significant differences were found in the proportions of macrolide- or doxycycline-resistant strains between S. suis serotype 2 and other serotypes. The results of antibiotic susceptibility testing presented in this study indicate that beta-lactams can be used in empirical treatment of human and pig S. suis infections in France.

An experimental model for post-weaning multisystemic wasting syndrome (PMWS) in growing piglets.

Post-weaning multisystemic wasting syndrome (PMWS) is a comparatively new disease of swine, and known to occur in France since 1996. A porcine circovirus type 2 (PCV2) is found in the lesions of affected piglets. Six piglets aged 10-13 weeks were obtained from a French PMWS-affected farm. Two showing characteristic signs of PMWS (palor, weakness and emaciation) remained in poor condition and were finally killed 6 and 9 days after their arrival in the experimental unit. Tissue homogenates from these two piglets were used to reproduce mild PMWS in specific pathogen-free (SPF) piglets. This mild PMWS consisted of pyrexia (up to 41.7 degrees C) and growth retardation (up to 30% of weight reduction compared with controls) commencing 1 week after infection and lasting 3 weeks. In seven additional trials, pyrexia, growth retardation and lesions characteristic of PMWS were consistently produced in SPF and conventional piglets. However, only four of 55 inoculated SPF piglets (7.2%) showed severe wasting disease. One died and the others had to be killed 3 to 4 weeks after inoculation. None of the inoculated animals developed antibodies to any common swine viruses or bacteria, but clear evidence of PCV2 seroconversion was obtained. Our results therefore strongly suggest that PCV2 is the primary aetiological agent of PMWS.

Production of muraminidase-released protein (MRP), extracellular factor (EF) and suilysin by field isolates of Streptococcus suis capsular types 2, 1/2, 9, 7 and 3 isolated from swine in France.

A total of 323 isolates of Streptococcus suis recovered from diseased or healthy pigs in France were serotyped. The presence of virulence-related proteins, Muraminidase-Released Protein (MRP), Extracellular Factor (EF) and Suilysin was also studied in 122 isolates of capsular types 2, 1/2, 9, 7 and 3 to evaluate their implication in virulence of S. suis. Capsular types 2, 1/2, 9, 7 and 3 were the most frequently detected (93%), with 69% for the capsular type 2 alone. Capsular types 2, 1/2, 9, 7, 3, 1, 4, 8, 18, 10 and 12 were isolated from diseased pigs, whereas types 2, 7, 9, 1/2, and 3 originated from the nasal cavities or tonsils of healthy animals. Most of the S. suis type 2 isolates recovered from diseased pigs carried MRP+ EF- Suilysin- (46%) or MRP+ EF+ Suilysin+ (28%) phenotypes. The MRP+ EF- Suilysin- phenotype was also detected in 67% of S. suis type 2 strains isolated from healthy pigs. The production of the virulence-related proteins was less frequently found in S. suis types 1/2, 9, 7 and 3 recovered either from diseased or healthy pigs. In this study, all the capsular type 1/2 strains were MRP+ EF- Suilysin- and all the S. suis type 7 harboured an MRP- EF- Suilysin- phenotype. The MRP- EF- Suilysin- phenotype was found in S. suis types 2, 3, 7 and 9 isolated from septicaemia, meningitis, pneumonia, and pleurisy. These results suggest that the presence of these proteins should not be used as a single condition for classifying the virulence of a field isolate in France.

A PCR assay used to study aerosol transmission of Actinobacillus pleuropneumoniae from samples of live pigs under experimental conditions.

The study describes a polymerase chain reaction (PCR) assay for the detection of Actinobacillus pleuropneumoniae. The test is based on the amplification of the omlA gene coding for an outer membrane protein of A. pleuropneumoniae. To test the specificity of the reaction, 19 other bacterial species related to A. pleuropneumoniae or isolated from pigs were assayed. They were all found negative in the PCR assay. The detection threshold of the test was 10(2) A. pleuropneumoniae CFU/assay. The test was then applied to the detection of A. pleuropneumoniae from tonsillar biopsies and tracheobronchial lavage fluids of pigs without a culture step. The detection of A. pleuropneumoniae in these samples was performed by PCR, by conventional culture and by bacteriology with immunomagnetic beads. The number of samples that were found positive by PCR was almost three times higher than the number of samples from which A. pleuropneumoniae was isolated by both bacteriological techniques. The detection of A. pleuropneumoniae in these samples allowed us to demonstrate its aerosol transmission to pigs under experimental conditions. The trial involved 18 specific pathogen free pigs. Six pigs, infected with A. pleuropneumoniae, were located in a unit A, together with four non-infected animals (contact pigs). Eight non-infected pigs (reporter pigs) were located in a unit B, adjacent to A. We detected A. pleuropneumoniae in samples from infected animals but also from 'contact' (unit A) and 'reporter' (unit B) pigs. The results of this study show that the simple preparation of the samples followed by the PCR assay may be a useful tool for epidemiological studies.

Capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus. Structural study of an undecasaccharide obtained by lithium degradation.

The capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus has been subjected to a specific degradation with lithium in ethylenediamine. The released undecasaccharide attached to one unit of tetrahydroxycyclopentanecarboxylic acid has been characterized by a combination of 2D nuclear magnetic resonance spectroscopy, mass spectrometry, monosaccharidic composition and linkage analyses. From the overlap of the structure of this oligosaccharide with previously identified di-, tri- and pentasaccharides released by mild acid hydrolysis, the capsular polysaccharide was deduced to have a pentadecasaccharide repeating unit with the following structure:

Efficacy of doxycycline in feed for the control of pneumonia caused by Pasteurella multocida and Mycoplasma hyopneumoniae in fattening pigs.

A multicentre, controlled, randomised and blinded study was carried out in three French pig herds to assess the efficacy of doxycycline administered in the feed for the control of pneumonia. About 20 per cent of 363 pigs from the three fattening units were diseased at the start of the study. Pneumonic lesions were found on pigs examined postmortem and Pasteurella multocida was isolated from the lungs of pigs in all the herds. Mycoplasma hyopneumoniae infection was confirmed either by detection in pneumonic lungs or by seroconversion in pigs sampled three weeks apart. P multocida, Bordetella bronchiseptica and Actinobacillus pleuropneumoniae were isolated from 64 per cent, 50 per cent and 2 per cent, respectively, of 148 nasal swabs. The following variables were significantly different between the treated and untreated groups (P < or = 0.001): the incidence of diseased pigs during the three weeks from the start of treatment (8.1 per cent in treated group v 35.4 per cent in control group), mean daily weight gain over the same period (934 g/day in the treated group v 834 g/day in the control group) and the cure rate of pigs which were diseased at the start of treatment (73.5 per cent in treated group v 35.3 per cent in control group). These data demonstrate that an average dose of 11 mg doxycycline/kg bodyweight per day in feed for eight days was effective in controlling pneumonia due to P multocida and M hyopneumoniae in these fattening pigs.

Structural characterization of three aldobiuronic acids derived from the capsular polysaccharide produced by the thermophilic cyanobacterium Mastigocladus laminosus.

This study deals with the chemical characterization of a capsular polysaccharide (CPS) produced by a thermal biomass formed by the cyanobacterium Mastigocladus laminosus. Acid hydrolysis performed on the purified polysaccharide has led to the isolation of several acid-resistant oligosaccharides. Two of them have already been reported and assigned as: alpha - GlcA - (1 --> 2) - alpha - GalA - (1 --> 2) - Man. and alpha - GlcA - (1 --> 2) - alpha - GalA - (1 --> 2) - beta - Man - (1 --> 4) - beta - Gal(1 --> 2) - Rha. In this report, results on the isolation and partial purification of three supplementary oligosaccharidic units are presented. Gas chromatography-mass spectrometry (GC-MS) and H-nuclear magnetic resonance (NMR) spectroscopy investigations allowed them to be assigned as three aldobiuronic acids with the following structures: alpha - GlcA - (1 --> 3) - Gal alpha - GlcA - (1 --> 3) - Fuc alpha - GalA - (1 --> 3) - Fuc.