In silico segmentations of lentivirus envelope sequences

BACKGROUND: The gene encoding the envelope of lentiviruses exhibits a considerable plasticity, particularly the region which encodes the surface (SU) glycoprotein. Interestingly, mutations do not appear uniformly along the sequence of SU, but they are clustered in restricted areas, called variable (V) regions, which are interspersed with relatively more stable regions, called constant (C) regions. We look for specific signatures of C/V regions, using hidden Markov models constructed with SU sequences of the equine, human, small ruminant and simian lentiviruses. RESULTS: Our models yield clear and accurate delimitations of the C/V regions, when the test set and the training set were made up of sequences of the same lentivirus, but also when they were made up of sequences of different lentiviruses. Interestingly, the models predicted the different regions of lentiviruses such as the bovine and feline lentiviruses, not used in the training set. Models based on composite training sets produce accurate segmentations of sequences of all these lentiviruses. CONCLUSION: Our results suggest that each C/V region has a specific statistical oligonucleotide composition, and that the C (respectively V) regions of one of these lentiviruses are statistically more similar to the C (respectively V) regions of the other lentiviruses, than to the V (respectively C) regions of the same lentivirus

Réflexion sur les rôles d’une conseillère pédagogique relativement aux dimensions du développement professionnel de l’enseignant dans un contexte d’implantation d’une communauté d’apprentissage professionnelle

Cet essai professionnel se divise en quatre chapitres. Le premier fait état des changements survenus en éducation au cours des dernières années. Ces transformations influencent le développement professionnel des enseignants ainsi que les rôles des CP et leur complexité. Avec l’implantation des CAP, qui constituent à elles seules un changement de taille, tous les intervenants scolaires, dont les CP, doivent s’adapter. Ce chapitre se termine par la description du problème, la question de recherche et les objectifs qui motivent la réalisation de cet essai

Neutropenia as an adverse event following vaccination : results from randomized clinical trials in healthy adults and systematic review

Background : In the context of early vaccine trials aimed at evaluating the safety profile of novel vaccines, abnormal haematological values, such as neutropenia, are often reported. It is therefore important to evaluate how these trials should be planned not to miss potentially important safety signals, but also to understand the implications and the clinical relevance. Methodology : We report and discuss the results from five clinical trials (two with a new Shigella vaccine in the early stage of clinical development and three with licensed vaccines) where the absolute neutrophil counts (ANC) were evaluated before and after vaccination. Additionally, we have performed a systematic review of the literature on cases of neutropenia reported during vaccine trials to discuss our results in a more general context. Principal Findings : Both in our clinical trials and in the literature review, several cases of neutropenia have been reported, in the first two weeks after vaccination. However, neutropenia was generally transient and had a benign clinical outcome, after vaccination with either multiple novel candidates or well-known licensed vaccines. Additionally, the vaccine recipients with neutropenia frequently had lower baseline ANC than non-neutropenic vaccinees. In many instances neutropenia occurred in subjects of African descent, known to have lower ANC compared to western populations. Conclusions : It is important to include ANC and other haematological tests in early vaccine trials to identify potential safety signals. Post-vaccination neutropenia is not uncommon, generally transient and clinically benign, but many vaccine trials do not have a sampling schedule that allows its detection. Given ethnic variability in the level of circulating neutrophils, normal ranges taking into account ethnicity should be used for determination of trial inclusion/exclusion criteria and classification of neutropenia related adverse events

Synthesis of 4-Amino-1-Hydroxy-Butane-1,1-Diphosphonate (AHBDP) - Stannous Complexes for the Preparation of Ahbdp-Sn(II)-Tc and its Biodistribution in Rats

The new potential tracer of bone imaging, AHBDP-Sn(II)-TcO.3H2O was synthesized by reducing the TcO4− to TcO2+ in the presence of AHBDP and Sn(ll)’s reducing agent. We found that tin rapidly forms a stable complex with AHBDP, giving AHBDP-Sn(II).3H2O. In the excess of AHBDP-Sn(ll).3H2O, the AHBDP-Sn(II).3H2O coordinates with TcO2+ to give AHBDP-Sn(II)-TcO.3H2O which could polymerise or oligomerise to give hydrophobic species. The overall process appears as a first-order reaction (K= 0.67 ± 0.005s−1). In rats, the fixation of AHBDP-Sn(II)-99mTcO. 3H2O on bone is homogeneous and the scintigraphic images have the same quality as those of 1-hydroxymethane-1,1-diphosphonate-Technetium (HMDP-99mTc). The activity in non-target organs was neglible

Polycyclic aromatic hydrocarbon components contribute to the mitochondria-antiapoptotic effect of fine particulate matter on human bronchial epithelial cells via the aryl hydrocarbon receptor

<p>Abstract</p> <p>Background</p> <p>Nowadays, effects of fine particulate matter (PM_2.5) are well-documented and related to oxidative stress and pro-inflammatory response. Nevertheless, epidemiological studies show that PM_2.5exposure is correlated with an increase of pulmonary cancers and the remodeling of the airway epithelium involving the regulation of cell death processes. Here, we investigated the components of Parisian PM_2.5involved in either the induction or the inhibition of cell death quantified by different parameters of apoptosis and delineated the mechanism underlying this effect.</p> <p>Results</p> <p>In this study, we showed that low levels of Parisian PM_2.5are not cytotoxic for three different cell lines and primary cultures of human bronchial epithelial cells. Conversely, a 4 hour-pretreatment with PM_2.5prevent mitochondria-driven apoptosis triggered by broad spectrum inducers (A23187, staurosporine and oligomycin) by reducing the mitochondrial transmembrane potential loss, the subsequent ROS production, phosphatidylserine externalization, plasma membrane permeabilization and typical morphological outcomes (cell size decrease, massive chromatin and nuclear condensation, formation of apoptotic bodies). The use of recombinant EGF and specific inhibitor led us to rule out the involvement of the classical EGFR signaling pathway as well as the proinflammatory cytokines secretion. Experiments performed with different compounds of PM_2.5suggest that endotoxins as well as carbon black do not participate to the antiapoptotic effect of PM_2.5. Instead, the water-soluble fraction, washed particles and organic compounds such as polycyclic aromatic hydrocarbons (PAH) could mimic this antiapoptotic activity. Finally, the activation or silencing of the aryl hydrocarbon receptor (AhR) showed that it is involved into the molecular mechanism of the antiapoptotic effect of PM_2.5at the mitochondrial checkpoint of apoptosis.</p> <p>Conclusions</p> <p>The PM_2.5-antiapoptotic effect in addition to the well-documented inflammatory response might explain the maintenance of a prolonged inflammation state induced after pollution exposure and might delay repair processes of injured tissues.</p

Retroviruses and comparative pathology

Retroviruses are RNAviruses that infect and can induce disease in humans and animals. Retroviral infections in small ruminants and horses share common features: when serology is available, infected animals can be seronegative; infected animals inconstantely develop disease; infection and disease can be experimentaly induced. Animal retroviruses are a cause of spontaneous diseases, transmissible among animals and model systems of human diseases.Les rétrovirus sont des virus à ARN qui infectent et sont susceptibles de rendre malade l'homme et l'animal. Les infections rétrovirales des petits ruminants et des équidés ont des caractéristiques communes: lorsqu'il existe un diagnostic sérologique, des animaux infectés peuvent être séronégatifs; les animaux infectés ne sont pas toujours malades; l'infection et la maladie peuvent être reproduits expérimentalement. Au total, les rétrovirus animaux, en particulier des petits ruminants et des équidés, sont une cause de maladies spontanées, transmissibles chez ces animaux et peuvent être utilisés comme modèle de plusieurs maladies humaines

Lung progenitors from lambs can differentiate into specialized alveolar or bronchiolar epithelial cells.

26International audienceBACKGROUND: Airways progenitors may be involved in embryogenesis and lung repair. The characterization of these important populations may enable development of new therapeutics to treat acute or chronic lung disease. In this study, we aimed to establish the presence of bronchioloalveolar progenitors in ovine lungs and to characterize their potential to differentiate into specialized cells. RESULTS: Lung cells were studied using immunohistochemistry on frozen sections of the lung. Immunocytochemistry and flow cytometry were conducted on ex-vivo derived pulmonary cells. The bronchioloalveolar progenitors were identified by their co-expression of CCSP, SP-C and CD34. A minor population of CD34pos/SP-Cpos/CCSPpos cells (0.33% +/- 0.31) was present ex vivo in cell suspensions from dissociated lungs. Using CD34 magnetic positive-cell sorting, undifferentiated SP-Cpos/CCSPpos cells were purified (>80%) and maintained in culture. Using synthetic media and various extracellular matrices, SP-Cpos/CCSPpos cells differentiated into either club cells (formerly named Clara cells) or alveolar epithelial type-II cells. Furthermore, these ex vivo and in vitro derived bronchioloalveolar progenitors expressed NANOG, OCT4 and BMI1, specifically described in progenitors or stem cells, and during lung development. CONCLUSIONS: We report for the first time in a large animal the existence of bronchioloalveolar progenitors with dual differentiation potential and the expression of specialized genes. These newly described cell population in sheep could be implicated in regeneration of the lung following lesions or in development of diseases such as cancers

First observation of a chimpanzee with albinism in the wild : social interactions and subsequent infanticide

Maël Leroux was funded via the Swiss National Science Foundation grant awarded to Simon W. Townsend (31003A_153065). Pawel Fedurek was funded via the European Research Council project grant awarded to Catherine Crockford (grant agreement number: 679787).Albinism- the congenital absence of pigmentation- is a very rare phenomenon in animals due to the significant costs to fitness of this condition. Both humans and non-human individuals with albinism face a number of challenges, such as reduced vision, increased exposure to ultraviolet radiation, or compromised crypticity resulting in an elevated vulnerability to predation. However, while observations of social interactions involving individuals with albinism have been observed in wild non-primate animals, such interactions have not been described in detail in non-human primates (hereafter, primates). Here, we report, to our knowledge, the first sighting of an infant with albinism in wild chimpanzees (Pan troglodytes schweinfurthii), including social interactions between the infant, its mother, and group members. We also describe the subsequent killing of the infant by conspecifics as well as their behavior towards the corpse following the infanticide. Finally, we discuss our observations in relation to our understanding of chimpanzee behavior or attitudes towards individuals with very conspicuous appearances.Publisher PDFPeer reviewe

Adaptive optics telemetry standard: Design and specification of a novel data exchange format

Context. The amount of adaptive optics (AO) telemetry generated by visible/near-infrared ground-based observatories is ever greater, leading to a growing need for a standardised data exchange format to support performance analysis, AO research, and development activities that involve large-scale telemetry mining, processing, and curation.Aims. This paper introduces the Adaptive Optics Telemetry (AOT) data exchange format as a standard for sharing AO telemetry from visible/infrared ground-based observatories. AOT is based on the flexible image transport system (FITS) and aims to provide unambiguous and consistent data access across various systems and configurations, including natural and single- or multiple-laser guide-star AO systems.Methods. We designed AOT with a focus on two key use cases: atmospheric turbulence parameter estimation and point-spread function reconstruction. We prototyped and tested the design using existing AO telemetry datasets from multiple systems: single conjugate with natural and laser guide stars, tomographic systems with multi-channel wavefront sensors, and single- and multi-wavefront correctors in systems featuring either a Shack-Hartmann or Pyramid as the main wavefront sensor.Results. The AOT file structure has been thoroughly defined, with specified data fields, descriptions, data types, units, and expected dimensions. To support this format, we have developed a Python package that enables the data conversion, reading, writing, and exploration of AOT files; it has been made publicly available and is compatible with a general-purpose Python package manager. We have demonstrated the flexibility of the AOT format by packaging data from five different instruments, installed on different telescopes