Background In 2009, we reported a novel form of delayed anaphylaxis to red meat, which is related to serum IgE antibodies to the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal). Most of these patients had tolerated meat for many years previously. The implication is that some exposure in adult life had stimulated the production of these IgE antibodies. Objectives To investigate possible causes of this IgE antibody response, focusing on evidence related to tick bites, which are common in the region where these reactions occur. Methods Serum assays were carried out using biotinylated proteins and extracts bound to a streptavidin ImmunoCAP. Results Prospective studies on IgE antibodies in three subjects following tick bites showed an increase in IgE to alpha-gal of twenty-fold or greater. Other evidence included i) a strong correlation between histories of tick bites and IgE to alpha-gal (χ2=26.8, p<0.001), ii) evidence that these IgE antibodies are common in areas where the tick Amblyomma americanum is common, and iii) a significant correlation between IgE antibodies to alpha-gal and IgE antibodies to proteins derived from A. americanum (rs=0.75, p<0.001). Conclusion The results presented here provide evidence that tick bites are a cause, or possibly the only cause, of IgE specific for alpha-gal in this area of the United States. Both the number of subjects becoming sensitized and the titer of IgE antibodies to alpha-gal are striking. Here we report the first example of a response to an ectoparasite giving rise to an important form of food allergy.

An immortal line of pigmented melanocytes, "melan-a", has been derived from normal epidermal melanoblasts from embryos of inbred C57BL mice. The conditions favouring proliferation of these cells largely resemble those for normal, non-established mouse melanoblasts and melanocytes, and include a low extracellular pH and the presence of a tumour promoter, tetradecanoyl phorbol acetate (TPA) or teleocidin. Melan-a cells have the diploid chromosome number and do not form tumours in syngeneic or nude mice. They are therefore the first known line of non-tumorigenic mouse melanocytes, although an aneuploid melanocyte line of untested tumorigenicity has been reported (Sato et al., 1985). Melan-a cells are syngeneic with the B16 melanoma and its sublines, and provide an excellent parallel non-tumorigenic line for studies of the cellular and molecular basis of melanoma malignancy.

Abstract. Diagnosis of gastrointestinal parasites has traditionally relied on stool microscopy, which has low diagnostic sensitivity and specificity. We have developed a novel, rapid, high-throughput quantitative multi-parallel real-time polymerase chain reaction (qPCR) platform. Species-specific primers/probes were used for eight common gastrointestinal parasite pathogens: Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Giardia lamblia, Cryptosporidium spp., Entamoeba histolytica, Trichuris trichiura, and Strongyloides stercoralis. Stool samples from 400 13-month-old children in rural Ecuador were analyzed and the qPCR was compared with a standard direct wet mount slide for stool microscopy, as were 125 8-14-year-old children before and after anthelmintic treatment. The qPCR showed higher detection rates for all parasites compared with direct microscopy, Ascaris (7.0% versus 5.5%) and for Giardia (31.5% versus 5.8%). Using an enhanced DNA extraction method, we were able to detect T. trichiura DNA. These assays will be useful to refine treatment options for affected populations, ultimately leading to better health outcomes.

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