St. Columba, Silnán, and the 'Male Bovine' (VC 2.17)

At Vita Columbae VC 2.17, Adomnán has severely misunderstood a written source which originally described how Columba ordered one party to a dispute, an alleged maleficus ‘evil-doer’ called Silnán, to milk a sick cow in order to settle the dispute by demonstrating that its contaminated milk was the real, hidden cause of the harm which had occasioned the dispute. Adomnán misread a description of a bos maculosus ‘pock-marked bovine’ to refer to a bos masculus ‘male bovine’, and proceeded to misunderstand the story as the description of some form of contest between Columba and a maleficus ‘sorcerer’.

Tryptophan degradation in irritable bowel syndrome: evidence of indoleamine 2,3-dioxygenase activation in a male cohort

Background: Irritable bowel syndrome (IBS) is a common disorder that affects 10–15% of the population. Although characterised by a lack of reliable biological markers, the disease state is increasingly viewed as a disorder of the brain-gut axis. In particular, accumulating evidence points to the involvement of both the central and peripheral serotonergic systems in disease symptomatology. Furthermore, altered tryptophan metabolism and indoleamine 2,3-dioxygenase (IDO) activity are hallmarks of many stress-related disorders. The kynurenine pathway of tryptophan degradation may serve to link these findings to the low level immune activation recently described in IBS. In this study, we investigated tryptophan degradation in a male IBS cohort (n = 10) and control subjects (n = 26). Methods: Plasma samples were obtained from patients and healthy controls. Tryptophan and its metabolites were measured by high performance liquid chromatography (HPLC) and neopterin, a sensitive marker of immune activation, was measured using a commercially available ELISA assay. Results: Both kynurenine levels and the kynurenine:tryptophan ratio were significantly increased in the IBS cohort compared with healthy controls. Neopterin was also increased in the IBS subjects and the concentration of the neuroprotective metabolite kynurenic acid was decreased, as was the kynurenic acid:kynurenine ratio. Conclusion: These findings suggest that the activity of IDO, the immunoresponsive enzyme which is responsible for the degradation of tryptophan along this pathway, is enhanced in IBS patients relative to controls. This study provides novel evidence for an immune-mediated degradation of tryptophan in a male IBS population and identifies the kynurenine pathway as a potential source of biomarkers in this debilitating condition.

Grooming and hygienic behaviours of the honey bee (Apis mellifera) toward the parasitic mite Varroa destructor

Despite a multitude of environmental stressors, the Varroa mite is still regarded as the greatest cause of honey bee mortality in its invaded range. Breeding honey bees that are resistant to the mite is an important area of research. This thesis aimed to gain a better understanding of the grooming and hygienic behaviours of Russian honey bees (RHB). The effect of a break in the synchrony of a mite’s life cycle on reproductive success was tested through brood inoculation experiments. Mites released by hygienic behaviour and forced to enter a new cell are less likely to lay male offspring. Through laboratory cage assays it was found that daughter mites are more susceptible to grooming behaviour. A new method of marking Varroa mites was developed which would enable a single cohort of mites to be followed after inoculation. A strong brood removal trait was noticed in RHB colonies, therefore they were tested for Varroa sensitive hygienic (VSH) behaviour. RHB demonstrated levels of VSH as high as the USDA line bred specifically for this behaviour. In addition the same QTL found to be responsible for the trait in VSH bees, was associated with VSH in RHB stock. Previous work showed that the ratio of older mites to total trapped mites (O/T) in the debris of honey bee colonies demonstrated the strongest association with colony infestation. This research showed that O/T is associated with VSH and brood removal behaviour. In addition, bees that displayed high levels of VSH in this study were also more likely to spend a longer amount of time grooming in laboratory assays. This indicates that both grooming and hygienic behaviours play important roles in the resistance of RHB stock. Their likelihood to be expressed by other stocks is discussed and recommendations for further research are provided.