A 1-Mb resolution radiation hybrid map of the canine genome

The purebred dog population consists of >300 partially inbred genetic isolates or breeds. Restriction of gene flow between breeds, together with strong selection for traits, has led to the establishment of a unique resource for dissecting the genetic basis of simple and complex mammalian traits. Toward this end, we present a comprehensive radiation hybrid map of the canine genome composed of 3,270 markers including 1,596 microsatellite-based markers, 900 cloned gene sequences and ESTs, 668 canine-specific bacterial artificial chromosome (BAC) ends, and 106 sequence-tagged sites. The map was constructed by using the RHDF5000-2 whole-genome radiation hybrid panel and computed by using MULTIMAP and TSP/CONCORDE. The 3,270 markers map to 3,021 unique positions and define an average intermarker distance corresponding to 1 Mb. We also define a minimal screening set of 325 highly informative well spaced markers, to be used in the initiation of genome-wide scans. The well defined synteny between the dog and human genomes, established in part as a function of this work by the identification of 85 conserved fragments, will allow follow-up of initial findings of linkage by selection of candidate genes from the human genome sequence. This work continues to define the canine system as the method of choice in the pursuit of the genes causing mammalian variation and disease.     

Activation of the ubiquitin proteolytic pathway in human septic heart and diaphragm

ObjectiveMechanisms of sepsis-induced myocardial and diaphragmatic alteration are multiple and remain largely unknown, particularly in humans. In the present study, we compared the inducible nitric oxide synthase (NOS-2) expression, the peroxynitrite production and the expression and activation of the ubiquitin proteolytic pathway in the wall of the 4 cardiac chambers, in the diaphragm, and in the rectus abdominis.PatientsSeven patients who died from septic shock associated with a myocardial depression and 5 nonseptic (control) patients.Measurements and resultsWe evaluated protein expression by Western blot. Nitrotyrosin and ubiquitin residues were localized by immunofluorescence. NOS-2, nitrated proteins, free ubiquitin, and ubiquitinated proteins are overexpressed in the wall of the four cardiac cavities, in the diaphragm and in the rectus abdominis of septic patients at a similar level. Ubiquitinated proteins with a molecular mass of 50, 35, 30, and 25 kD were consistently detected in heart, diaphragm, and rectus abdominis of septic shock patients but lacking in nonseptic patients. In situ immunolabelling of ubiquitin showed a colocalisation with nitrotyrosine residues at the sarcomeric level of cardiac myocytes in septic patients.ConclusionsThis study showed the first evidence for the activation of the proteolytic ubiquitin–proteasome pathway in human heart and diaphragm in septic shock.     

Macrophages and dendritic cells express tight junction proteins and exchange particles in an in vitro model of the human airway wall

The human airway epithelium serves as structural and functional barrier against inhaled particulate antigen. Previously, we demonstrated in an in vitro epithelial barrier model that monocyte derived dendritic cells (MDDC) and monocyte derived macrophages (MDM) take up particulate antigen by building a trans-epithelial interacting network. Although the epithelial tight junction (TJ) belt was penetrated by processes of MDDC and MDM, the integrity of the epithelium was not affected. These results brought up two main questions: (1) Do MDM and MDDC exchange particles? (2) Are those cells expressing TJ proteins, which are believed to interact with the TJ belt of the epithelium to preserve the epithelial integrity?The expression of TJ and adherens junction (AJ) mRNA and proteins in MDM and MDDC monocultures was determined by RT-PCR, and immunofluorescence, respectively. Particle uptake and exchange was quantified by flow cytometry and laser scanning microscopy in co-cultures of MDM and MDDC exposed to polystyrene particles (1 μm in diameter).MDM and MDDC constantly expressed TJ and AJ mRNA and proteins. Flow cytometry analysis of MDM and MDDC co-cultures showed increased particle uptake in MDDC while MDM lost particles over time. Quantitative analysis revealed significantly higher particle uptake by MDDC in co-cultures of epithelial cells with MDM and MDDC present, compared to co-cultures containing only epithelial cells and MDDC.We conclude from these findings that MDM and MDDC express TJ and AJ proteins which could help to preserve the epithelial integrity during particle uptake and exchange across the lung epithelium.     

Hidden administration of 5-APB in a dancing club of New Caledonia documented by urine analysis: about 3 cases

1-Benzofuran-5-ylpropan-2-amine or 5-APB is a new psychoactive substance (NPS) with empathic effects close to ecstasy (MDMA). Although 5-APB has been observed in fatality cases, the drug has not yet been reported in the context of hidden administration for behaviour impairment, also known as drug-facilitated crime. Such a situation was recently observed on 3 separate occasions in the same dancing club of New Caledonia. It involves 3 women, aged 27, 29, and 33 years who presented, after having drunk a cocktail, anxiety, abnormal movements of the inferior jaw, and aggressiveness. No memory loss was noticed. About 12 h after the event, a urine specimen was collected in the 3 cases. Comprehensive toxicology was requested and only 5-APB was identified, at 6, 8, and 14 ng/mL. Urine ethanol tested negative, which is consistent with the limited intake before the event occurred. These results have demonstrated that NPS are circulating in New Caledonia, which was not previously reported, and that 5-APB, like ecstasy, can be used to modify the behaviour of a subject, as it can be done by a chemical weapon.