Analysis of caecal mucosal inflammation and immune modulation during Anoplocephala perfoliata infection of horses.

Anoplocephala perfoliata is the commonest equine tapeworm, the adult parasites are attached in groups close to the ileocaecal valve causing marked inflammatory pathology. This work aimed to characterize the nature of the in vivo mucosal immune response to A perfoliata, and to investigate the role of A perfoliata excretory-secretory components in modulating in vitro immune responses. Real-time PCR detected elevation of IL13 and TGFß transcription in early-stage A perfoliata infection. In late-stage infection, IL-13, IL4 and Ifn transcripts were reduced while the regulatory cytokines, TGFß, IL10 and the transcription factor FOXP3 were increased in tissue close to the site of A perfoliata attachment; indicating downregulation of T-cell responses to A perfoliata. In vitro, A perfoliata excretory-secretory products induced apoptosis of the Jurkat T-cell line and premature cell death of ConA stimulated equine peripheral blood leucocytes. Analysis of cytokine transcription patterns in the leucocyte cultures showed a marked inhibition of IL-1 and IL-2 suggesting that a lack of T-cell growth factor transcription underlies the mechanism of the induced equine T-cell death. These preliminary findings suggest A perfoliata may have the ability to down-regulate host T-cell responses.

Equine nutrition in the post-operative colic: Survey of Diplomates of the American Colleges of Veterinary Internal Medicine and Veterinary Surgeons, and European Colleges of Equine Internal Medicine and Veterinary Surgeons.

BACKGROUND: Evidence is lacking concerning re-introduction of feed and water following colic surgery. OBJECTIVES: To describe current approaches of European and American specialists to re-introduction of feed and water in adult horses following surgical treatment of common intestinal lesions, assuming an uncomplicated recovery. STUDY DESIGN: Cross-sectional survey. METHODS: Electronic invitations, with a link to the online survey, were sent to 1,430 large animal specialists, including Diplomates of the ECVS, ACVS, ECEIM and ACVIM colleges. RESULTS: The response rate was 12.6% including partial respondent data. Responses for each multiple-choice question were between 123 and 178. Results are expressed as the percentage of the total number of responses and as a range where specific lesions are grouped together. Respondents reported that horses with large intestinal displacements were offered free choice water (63%-65%) within 3 hours (55%-63%), whereas horses with a small intestinal strangulating lesion were offered < 2 L water (64%-74%) 12-24 hours (28%-34%) post-operatively. Horses with a large colon displacement were offered feed within 3 hours of surgery (16%) with the majority offered feed 6-12 hours (35%-36%) post-operatively. Horses with small intestinal strangulating lesions and small colon lesions were offered feed 24-48 hours (34%-42%) after surgery. Following small intestinal, small colon or caecal lesions, horses were re-introduced feed in handfuls (79%-93%) and initially with grass (41%-54%). Horses with large colon displacements were mostly fed handfuls (49%-50%) of forage initially, but a number of respondents would offer larger quantities such as a small bucket (35%-37%) and predominantly of hay (50%-51%). MAIN LIMITATIONS: Low response rate. This study did not take into account common post-operative complications that may alter the clinical approach. CONCLUSIONS: This post-operative colic nutrition survey is the first to describe current clinical practice. Further research is required to investigate nutritional strategies in post-operative colic cases.

Adolescent drug dealing and race/ethnicity: a population-based study of the differential impact of substance use on involvement in drug trade.

BACKGROUND: Among adolescents, peers are an important source of drug procurement. However, little is known about factors associated with youths' involvement in drug trade. OBJECTIVES: The aim of the study is to identify substance use behaviors and contextual factors related to drug dealing among Black and White adolescents. METHODS: The sample consisted of 13,706 White and Black youths who completed the National Survey on Drug Use and Health. Separate backward logistic regression was used to identify substance use behaviors and contextual factors associated with drug dealing among Black and White youths. RESULTS: Among White youths, drug dealing was associated with use of marijuana, hallucinogens, cocaine, prescription drug misuse, availability of cocaine, and socioeconomic status (SES). Among Black youths, marijuana use and availability of crack and marijuana were associated with drug dealing. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: For White youths, substance use seems to be more relevant to drug dealing. Consequently, preventing and treating substance abuse may reduce involvement in the illegal distribution of drugs among White youths. More research is needed to identify risk and protective factors for drug dealing among Black adolescents.

Systemic and mucosal IgE antibody responses of horses to infection with Anoplocephala perfoliata.

Infection of horses with Anoplocephala perfoliata induces a severe inflammatory reaction of the caecal mucosa around the site of parasite attachment adjacent to the ileocecal valve. Lesions show epithelial erosion or ulceration of the mucosa with infiltration by eosinophils, lymphocytes and mast cells leading to oedema, gross thickening and fibrosis of the caecal wall. Despite this evidence of an inflammatory reaction to A. perfoliata within the mucosa of the caecum there is little information about the nature of the local immune response to A. perfoliata. An ELISA which assays serum IgG(T) antibodies to A. perfoliata excretory/secretory antigens has been developed as a diagnostic test. However, the specificity of the ELISA remains sub-optimal and the role of other isotypes in the immune response to A. perfoliata has not been reported. This study measured IgA, IgE and IgG(T) antibody responses to A. perfoliata excretory/secretory antigens in sera of 75 horses presented for slaughter. The prevalence of A. perfoliata infection, as confirmed by the presence of parasites in the terminal ileum, caecum or proximal colon, was 55%. A. perfoliata-specific IgG(T) and IgE antibodies were significantly elevated in infected horses compared to controls; IgA antibodies were also detected but did not differ between infected and control horses. Diagnosis by serum IgG(T) ELISA had a sensitivity of 78% and a specificity of 80%, by comparison the serum IgE ELISA had a sensitivity of just 44% with a specificity of 82% and therefore did not provide an improved diagnostic test. Western blots with sera from infected horses demonstrated IgE-binding to at least 10 separate components of excretory/secretory (E/S) antigens. A similar pattern was also found with IgG(T). Around 30% of horses had high levels of serum IgE which bound fucose-containing carbohydrate antigens on the parasite surface but this was unrelated to the presence of A. perfoliata infection. Immunoperoxidase staining detected numerous IgE-positive cells within lymphoid follicles in the caecal mucosa close to the site of A. perfoliata attachment and quantitative RT-PCR detected high levels of IgE transcription in the caecal mucosa of all horses. Mucosal synthesis of antibodies was confirmed by the demonstration of A. perfoliata-specific IgG(T) and IgE in the supernatant of lamina propria explant cultures that discriminated clearly between infected and uninfected horses. We conclude that there is an active immune response to A. perfoliata within the caecal mucosa involving local production of both IgG(T) and IgE antibody isotypes; but it remains unclear whether this immune response can reduce or eliminate parasite burden.