Size of supernumerary teats in sheep correlates with complexity of the anatomy and microenvironment.

Supernumerary nipples or teats (polythelia) are congenital accessory structures that may develop at any location along the milk line and have been implicated in the pathogenesis of mastitis. We describe the anatomy and histology of 27 spontaneously occurring supernumerary teats from 16 sheep, delineating two groups of teats - simple and anatomically complex - according to the complexity of the anatomy and microenvironment. Anatomically complex supernumerary teats exhibited significantly increased length and barrel diameter compared with simple supernumerary teats. A teat canal and/or teat cistern was present in anatomically complex teats, with smooth muscle fibres forming a variably well-organised encircling teat sphincter. Complex supernumerary teats also exhibited immune cell infiltrates similar to those of normal teats, including lymphoid follicle-like structures at the folds of the teat cistern-teat canal junction, and macrophages that infiltrated the peri-cisternal glandular tissue. One complex supernumerary teat exhibited teat end hyperkeratosis. These anatomical and histological features allow inference that supernumerary teats may be susceptible to bacterial ingress through the teat canal and we hypothesise that this may be more likely in those teats with less well-organised encircling smooth muscle. The teat cistern of anatomically complex teats may also constitute a focus of milk accumulation and thus a possible nidus for bacterial infection, potentially predisposing to mastitis. We suggest that size of the supernumerary teat, and relationship to the main teats, particularly in the case of 'cluster teats', should be considerations if surgical removal is contemplated.British Veterinary Association Animal Welfare Foundation (BVA AWF) Norman Hayward Fun

Developing ovine mammary terminal duct lobular units have a dynamic mucosal and stromal immune microenvironment

Funder: University of Cambridge | Girton College, University of Cambridge (Girton); doi: https://doi.org/10.13039/501100000621Funder: University of Cambridge Herchel-Smith FundFunder: British Veterinary Association Animal Welfare Foundation Norman Hayward Fund ref NHF_2016_03_KHAbstract: The human breast and ovine mammary gland undergo striking levels of postnatal development, leading to formation of terminal duct lobular units (TDLUs). Here we interrogate aspects of sheep TDLU growth as a model of breast development and to increase understanding of ovine mammogenesis. The distributions of epithelial nuclear Ki67 positivity differ significantly between younger and older lambs. Ki67 expression is polarised to the leading edge of the developing TDLUs. Intraepithelial ductal macrophages exhibit periodicity and considerably increased density in lambs approaching puberty. Stromal macrophages are more abundant centrally than peripherally. Intraepithelial T lymphocytes are more numerous in older lambs. Stromal hotspots of Ki67 expression colocalize with immune cell aggregates that exhibit distinct organisation consistent with tertiary lymphoid structures. The lamb mammary gland thus exhibits a dynamic mucosal and stromal immune microenvironment and constitutes a valuable model system that provides new insights into postnatal breast development

The prevalence of leprosy in school-students and evaluation of school-based screening for leprosy: a Systematic Review

Leprosy is a Neglected Tropical Disease (NTD) causing significant physical and functional disabilities around the world. The objective of this systematic review was to evaluate school-based leprosy screening as a means of identifying early leprosy cases. Using a structured search method, 30 suitable publications were identified. Whilst all studies included in this review were found to identify cases of leprosy through school-based screening, sample sizes were high and numbers detected were small, raising concerns about the feasibility and sustainability of school-based screening as a stand-alone intervention for leprosy detection. For school-based screening programmes to become a sustainable intervention, the inclusion of both capacity building and health education components into school-based screening and intervention programmes should be further explored. More research is needed to consider alternate methods which maximise the efficiency of school-based approaches in the early case detection of leprosy. Also, cases found at school may be used to find further active cases via family and friends. School-based screening could be an effective solution for the early identification of leprosy particularly in areas of high endemicity, however to date there is limited data on its effectiveness compared with other interventions

The prevalence of leprosy in school-students and evaluation of school-based screening for leprosy: a Systematic Review

Leprosy is a Neglected Tropical Disease (NTD) causing significant physical and functional disabilities around the world. The objective of this systematic review was to evaluate school-based leprosy screening as a means of identifying early leprosy cases. Using a structured search method, 30 suitable publications were identified. Whilst all studies included in this review were found to identify cases of leprosy through school-based screening, sample sizes were high and numbers detected were small, raising concerns about the feasibility and sustainability of school-based screening as a stand-alone intervention for leprosy detection. For school-based screening programmes to become a sustainable intervention, the inclusion of both capacity building and health education components into school-based screening and intervention programmes should be further explored. More research is needed to consider alternate methods which maximise the efficiency of school-based approaches in the early case detection of leprosy. Also, cases found at school may be used to find further active cases via family and friends. School-based screening could be an effective solution for the early identification of leprosy particularly in areas of high endemicity, however to date there is limited data on its effectiveness compared with other interventions

An ovine model for investigation of the microenvironment of the male mammary gland

The specific biology of the male breast remains relatively unexplored in spite of the increasing global prevalence of male breast cancer. Delineation of the microenvironment of the male breast is restricted by the low availability of human samples and a lack of characterisation of appropriate animal models. Unlike the mouse, the male ovine gland persists postnatally. We suggest that the male ovine mammary gland constitutes a promising adjunctive model for the male human breast. In this study we evaluate the male ovine mammary gland microenvironment, comparing intact and neutered males. Assessment of the glandular histo-anatomy highlights the resemblance of the male gland to that of the neonatal female sheep and confirms the presence of rudimentary terminal duct lobular units. Irrespective of neutered status, cell proliferation in epithelial and stromal compartments is similarly low in males, and cell proliferation in epithelial cells and in the intralobular stroma is significantly lower than in pubertal female sheep. Between 42% and 72% of the luminal mammary epithelial cells in the male gland express the androgen receptor and expression is significantly reduced by neutering. Luminal epithelial cells within the intact and neutered male gland also express oestrogen receptor alpha, but minimal progesterone receptor expression is observed. The distribution of mammary leukocytes within the ducts and stroma is similar to the mammary gland of female sheep and females of other species. Both macrophages and T lymphocytes are intercalated in the epithelial bilayer and are more abundant in the intralobular stroma than the interlobular stroma, suggesting that they may have a protective immunological function within the vestigial glandular tissue of the male sheep. Mast cells are also observed within the stroma. These cells cluster near the glandular tissue and are frequently located adjacent to blood vessels. The abundance of mast cells is significantly higher in intact males compared to neutered males, suggesting that hormone signalling may impact mast cell recruitment. In this study, we demonstrate the utility of the male ovine mammary gland as a model for furthering our knowledge of postnatal male mammary biology.The Anatomical Societ

An ovine model for investigation of the microenvironment of the male mammary gland

Publication status: PublishedFunder: Anatomical Society PhD Studentship; doi: http://dx.doi.org/10.13039/100012070AbstractThe specific biology of the male breast remains relatively unexplored in spite of the increasing global prevalence of male breast cancer. Delineation of the microenvironment of the male breast is restricted by the low availability of human samples and a lack of characterisation of appropriate animal models. Unlike the mouse, the male ovine gland persists postnatally. We suggest that the male ovine mammary gland constitutes a promising adjunctive model for the male breast. In this study, we evaluate the male ovine mammary gland microenvironment, comparing intact and neutered males. Assessment of the glandular histo‐anatomy highlights the resemblance of the male gland to that of neonatal female sheep and confirms the presence of rudimentary terminal duct lobular units. Irrespective of neutered status, cell proliferation in epithelial and stromal compartments is similarly low in males, and cell proliferation in epithelial cells and in the intralobular stroma is significantly lower than in pubertal female sheep. Between 42% and 72% of the luminal mammary epithelial cells in the male gland express the androgen receptor and expression is significantly reduced by neutering. Luminal epithelial cells within the intact and neutered male gland also express oestrogen receptor alpha, but minimal progesterone receptor expression is observed. The distribution of leukocytes within the ducts and stroma is similar to the mammary gland of female sheep and females of other species. Both macrophages and T lymphocytes are intercalated in the epithelial bilayer and are more abundant in the intralobular stroma than the interlobular stroma, suggesting that they may have a protective immunological function within the vestigial glandular tissue of the male sheep. Mast cells are also observed within the stroma. These cells cluster near the glandular tissue and are frequently located adjacent to blood vessels. The abundance of mast cells is significantly higher in intact males compared to neutered males, suggesting that hormone signalling may impact mast cell recruitment. In this study, we demonstrate the utility of the male ovine mammary gland as a model for furthering our knowledge of postnatal male mammary biology.</jats:p