Variation in European harbour seal immune response genes and susceptibility to phocine distemper virus (PDV)

Phocine distemper virus (PDV) has caused two mass mortalities of European harbour seals (Phoca vitulina) in recent decades. Levels of mortality varied considerably among European populations in both the 1988 and 2002 epidemics, with higher mortality in continental European populations in comparison to UK populations. High levels of genetic differentiation at neutral makers among seal populations allow for the possibility that there could be potential genetic differences at functional loci that may account for some of the variation in mortality. Recent genome sequencing of carnivore species and development of genomic tools have now made it possible to explore the possible contribution of variation in candidate genes from harbour seals in relation to the differential mortality patterns. We assessed variation in eight genes (CD46, IFNG, IL4, IL8, IL10, RARa, SLAM and TLR2) encoding key proteins involved in host cellular interactions with Morbilliviruses and the relationship of variants to disease status. This work constitutes the first genetic association study for Morbillivirus disease susceptibility in a non-model organism, and for a natural mortality event. We found no variation in harbour seals from across Europe in the protein coding domains of the viral receptors SLAM and CD46, but SNPs were present in SLAM intron 2. SNPs were also present in IL8 p2 and RARa exon 1. There was no significant association of SLAM or RARa polymorphisms with disease status implying no role of these genes in determining resistance to PDV induced mortality, that could be detected with the available samples and the small number of polymorphisms indentified. However there was significant differentiation of allele frequencies among populations. PDV and other morbilliviruses are important models for wildlife epidemiology, host switches and viral evolution. Despite a negative result in this case, full sequencing of pinniped and other ‘non-model’ carnivore genomes will help in refining understanding the role of host genetics in disease susceptibility for these viruses.     

Priming of polymorphonuclear neutrophils by tumor necrosis factor alpha in whole blood: identification of two polymorphonuclear neutrophil subpopulations in response to formyl-peptides

We have used a cytofluorometric method to study the effect of tumor necrosis factor alpha (TNF) priming on the oxidative burst, FMLP- receptor expression and actin polymerization of whole blood polymorphonuclear neutrophils (PMN). This technique permits the study of single cells and, thus, allowed us to examine the responsiveness of PMN to TNF in whole blood. We found that TNF in whole blood strongly primed a subpopulation of PMN to produce H2O2 in response to FMLP stimulation, whereas TNF and FMLP alone did not have a significant effect. Furthermore, adding TNF to whole blood increased the capacity of a subpopulation of PMN to bind N-formyl peptides at 4 degrees C, a phenomenon that could account, at least in part, for the strong H2O2 production in response to FMLP after TNF priming. Dual-color cytometric analysis showed that TNF primed actin polymerization on the same subpopulation in response to FMLP. Because the PMN subpopulation, which strongly bound N-formyl peptides at 4 degrees C, was no longer detectable after 1 minute of incubation at 37 degrees C, our data suggest that TNF treatment of PMN in whole blood primes a subpopulation that actively cycles FMLP receptors. These results suggest that PMN in the circulation may respond weakly to bacterial peptides and that TNF may play a critical role in the induction of the oxidative burst in vivo.     

Impairment of death-inducing signalling complex formation in CD95-resistant human primary lymphoma B cells

Multiple mechanisms exist by which tumour cells can escape CD95-mediated apoptosis. Previous studies by our laboratory have shown that primary B cells from non-Hodgkin's Lymphoma (B-NHL) were resistant to CD95-induced cell death. In the current study, we have analysed the mechanisms underlying CD95 resistance in primary human lymphoma B cells. We report that FADD (FAS-associated death domain protein) and caspase-8 were constitutively expressed in lymphoma B cells and that the CD95 pathway was blocked upstream to caspase-8 activation. However, caspase-8 was processed and functional after treatment with staurosporine (STS). We found that the expression levels of FLICE (FADD-like interleukin-1 beta-converting enzyme)-Inhibitory Protein (c-FLIP) and Bcl-2-related proteins were heterogeneous in B-NHL cells and were not related to CD95 resistance. Finally, we report the absence of a CD95-induced signalling complex [death-inducing signalling complex (DISC)] in lymphoma B cells, with no FADD and caspase-8 recruitment to CD95 receptor. In contrast, DISC formation was observed in CD95-resistant non-tumoural (NT) B cells. Therefore, we propose that the absence of DISC formation in primary lymphoma B cells may contribute to protect these cells from CD95-induced apoptosis.     

Adrenoceptors and Colocolonic Inhibitory Reflex

The colocolonic inhibitory reflex ischaracterized by inhibition of proximal colonic motilityinduced by distal colonic distension. The aim of thisstudy was to investigate the underlying neuralmechanisms of this reflex, in vivo , using an isolatedloop of canine colon. In five beagle dogs, motility wasrecorded from an exteriorized colonic loop via a serosalstrain gauge connected to a digital data logger and chart recorder. Inflation of a balloon inthe distal colon resulted in inhibition of motility inthe isolated loop. Inhibition of motor activitypersisted following injection of propranolol (100g/kg intravenously), a -adrenoceptorantagonist, but was abolished following administrationof the ₂-adrenoceptor antagonistyohimbine (200 g/kg intravenously). This studyconfirms that the colocolonic inhibitory reflex is mediatedvia the extrinsic nerves to the colon. As the reflex wasabolished by ₂-, but not-adrenoceptor blockade, this indicates that thereflex pathway involves₂-adrenoceptors.     

Option Grids: Shared decision making made easier

Objective

To describe the exploratory use of short decision support tools for patients, called Option Grids. Option Grids are summary tables, using one side of paper to enable rapid comparisons of options, using questions that patients frequently ask (FAQs) and designed for face-to-face clinical encounters. To date, most evidence about ‘patient decision aids’ has been based on tools with high content levels, designed for patients to use independently, either before or after visits.

Methods

We studied the use of Option Grids in a quality improvement project, collecting field notes and conducting interviews with clinical teams.

Results

In the ‘Making Good Decisions in Collaboration’ (MAGIC) program, clinicians found that using Option Grids made it easier to explain the existence of options and reported a ‘handover’ effect, where patient involvement in decision making was enhanced.

Conclusion

Option Grids made options more visible and clinicians found it easier to undertake shared decision making when these tools were available. Used in a collaborative way, they enhance patients’ confidence and voice, increasing their involvement in collaborative dialogs.

Practice implications

Further work to confirm these preliminary findings is required, to measure processes and to assess whether these tools have similar impact in other clinical settings.