Single-step multiplex conventional and real-time reverse transcription polymerase chain reaction assays for simultaneous detection and subtype differentiation of Influenza A virus in swine.

Because pigs are considered intermediate hosts for the emergence of novel influenza virus reassortants with associated zoonotic potential, monitoring and characterization of circulating influenza viruses in pigs are important for adequate control of infection. For this, rapid molecular diagnostic methods other than immunoassays are needed. Three novel single-step multiplex reverse transcription polymerase chain reaction (RT-PCR) assays were developed in the current study for simultaneous detection and subtype differentiation of Influenza A virus in pigs. A conventional single-step pentaplex RT-PCR was designed for concomitant detection of the generic matrix (M) gene, hemagglutinin H1 and H3, and neuraminidase N1 and N2 genes of Swine influenza virus (SIV). In the other 2 single-step tetraplex real-time RT-PCR assays, the primers and fluorescent probes were targeted for the simultaneous detection of common M, H1, H3, and N2 SIV genes (first assay), and for M, H1, and H3 SIV genes and the H5 gene of highly pathogenic avian influenza virus of Eurasian lineage (second assay). The real-time RT-PCR assays had detection sensitivity limits ranging from 10(1) to 10(3) copies of respective in vitro RNA transcripts of M, H1, H3, H5, and N2 genes. The multiplex assays were evaluated by using SIV isolates, clinical specimens, and the appropriate synthetic template. The recent H1N1 pandemic strain isolated from pigs also was tested in simplex RT-PCR and real-time RT-PCR assays with the H1 primers and probes. The efficacy of the multiplex RT-PCR and real-time RT-PCR shows the suitability of multiplex RT-PCR and real-time RT-PCR for rapid subtype identification and monitoring in North American pigs of Influenza A virus.

Genetic diversity of porcine Norovirus and Sapovirus: Canada, 2005-2007.

Noroviruses and sapoviruses are members of the family Caliciviridae and emerging enteric pathogens of humans and animals. Since their discovery and characterization in swine, relatively few strains have been described in detail. In order to investigate their genetic diversity, a total of 266 fecal samples collected in the province of Quebec, Canada, between 2005 and 2007 were screened for the presence of caliciviruses by RT-PCR using broadly reactive primers. Genetically heterogeneous caliciviruses were detected on the majority of farms. Typical noroviruses related to known swine genotypes were present on 20% of the farms. Sapoviruses were detected on 75% of the farms and were the most heterogeneous group. Further characterization of selected strains in their 3' end parts was carried out for their classification and unveiled possibly new clusters of sapoviruses. No human-like noroviruses or sapoviruses were detected in the present study.

Estimated kyphosis and lordosis changes at follow-up in patients with idiopathic scoliosis.

The objective of this study was to verify the accuracy of surface measurements to estimate the magnitude of sagittal curvature changes at follow-up. Ninety-seven patients with idiopathic scoliosis were evaluated at two different visits (interval: 15.7 months). Kyphosis and lordosis were measured on the lateral radiograph. Surface measurements rely on localization of spinous process landmarks using a video-based system. Multiple regression analyses were performed to estimate the sagittal curvatures on the second visit. The regression was significant for both kyphosis and lordosis. The mean absolute difference between the estimate and the radiologic measurement was 3.3 degrees for kyphosis and 3.2 degrees for lordosis. The difference between the estimated change and the observed change between visits showed mean absolute differences of 3.4 degrees and 2.7 degrees, respectively. The proposed strategy could be used during follow-up to reduce patient irradiation without loss of sagittal information.

Additive effects of genotype, nutrient availability and type of tissue damage on the compensatory response of Salix planifolia ssp. planifolia to simulated herbivory.

Plant responses to herbivory include tolerance (i.e. compensatory growth) and defense. Several factors influence the tolerance of a plant following herbivory, including plant genetic identity, site nutrient availability, and previous and/or concurrent herbivory. We studied the effects of these factors on the compensatory response of Salix planifolia ssp. planifolia, a shrub species common in the boreal and subarctic regions of North America. We cloned several genets of S. planifolia and submitted them to simulated root and/or leaf herbivory while varying the nutrient availability. Simulated leaf herbivory was more detrimental to the plant than simulated root herbivory, reducing both above- and below-ground tissue production. Leaf demography was unaffected by either simulated herbivory treatment. There was some compensatory growth following simulated leaf and root herbivory, but only the root compartment responded to increased nutrient availability. Simulated leaf herbivory increased leaf transpiration and reduced stomatal resistance, suggesting increased carbon fixation. The unexpected finding of the experiment was the absence of interactions among factors (genotype, nutrient availability and type of tissue damage) on the compensatory response of S. planifolia. These factors thus have additive effects on the species' compensatory ability.