Environmental complexity positively impacts affective states of broiler chickens

Affective state can bias an animal's judgement. Animals in positive affective states can interpret ambiguous cues more positively ("optimistically") than animals in negative affective states. Thus, judgement bias tests can determine an animal's affective state through their responses to ambiguous cues. We tested the effects of environmental complexity and stocking density on affective states of broiler chickens through a multimodal judgement bias test. Broilers were trained to approach reinforced locations signaled by one color and not to approach unreinforced locations signaled by a different color. Trained birds were tested for latencies to approach three ambiguous cues of intermediate color and location. Broilers discriminated between cues, with shorter latencies to approach ambiguous cues closest to the reinforced cue than cues closest to the unreinforced cue, validating the use of the test in this context. Broilers housed in high-complexity pens approached ambiguous cues faster than birds in low-complexity pens-an optimistic judgement bias, suggesting the former were in a more positive affective state. Broilers from high-density pens tended to approach all cues faster than birds from low-density pens, possibly because resource competition in their home pen increased food motivation. Overall, our study suggests that environmental complexity improves broilers' affective states, implying animal welfare benefits of environmental enrichment.

Implications of Observer Variation in Gleason Scoring of Prostate Cancer on Clinical Management: A Collaborative Audit

BACKGROUND

Prostate cancer is the most frequently diagnosed cancer in men. Histological tumour grade is a strong predictor of outcome and helps determine what treatment options are offered. There are numerous studies on Inter-observer agreement/variability on prostate cancer grading. In this study, we were looking to establish if disconcordance between pathologists when grading prostate cancer, could affect treatment options offered to men.

METHODS

In Greater Manchester West Cancer Sector, all prostate cancer biopsies undergo a central review by three pathologists with a special interest in urological pathology prior to referral for treatment at specialist centres. 96 prostate biopsies (from 48 patients) from a District General Hospital were reviewed during a 6-month period (March 2014-September 2014). The original Gleason Score assigned was compared with the uropathologists consensus diagnosis established at the central review meeting. Any changes in patient risk and treatment plans were subsequently reviewed.

RESULTS

Of the 96 biopsies discussed at central review meeting, 24 (25%) biopsies from 19 patients underwent a change in Gleason grade and a subsequent change in risk for 13 (68%). Of the 19 patients, management plans could be affected for 9 patients (47%) and treatment options could potentially be affected for 5 (26%).

CONCLUSION

This study shows that where disconcordance between pathologists is present, there is the potential to affect patient management. A central review process can help to minimize the effect over or undergrading can have on the patient and should be considered a necessary step in the management of prostate cancer.

Equine T lymphocytes express MHC class II antigens

Six anti-HLA class II mouse monoclonal antibodies (mAbs) were used in conjunction with a rat monoclonal antibody raised against horse lymphocytes to define class II major histocompatibility complex (MHC) molecules in the horse. By utilizing an ELISA assay and complement dependent lymphocytotoxicity assay, five out of the six anti-HLA class II antibodies and the rat anti-horse monoclonal antibody were found to react with a high percentage of peripheral blood lymphocytes. Flow cytometry demonstrated a variable antigen density on peripheral blood lymphocytes and clear evidence for expression by lymphocytes that carried no detectable surface immunoglobulin. None of the antibodies reacted with equine platelets. The mAbs immunoprecipitated an antigenic complex of Mr 29,000-33,000 from horse lymphocytes. It appears that the distribution of MHC class II antigens in the horse is different from that in man but is similar to that in the dog, since MHC class II antigens are expressed on resting peripheral blood lymphocytes which lack membrane-bound immunoglobulins. Correlations between the distribution of MHC class II antigens on lymphocyte subpopulations and their role in immunological phenomena may contribute to our understanding of the functional properties of these molecules.