231 research outputs found

    Signalling Pathways Implicated in Early Mammary Gland Morphogenesis and Breast Cancer

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    Specification of mammary epithelial cell fate occurs during embryogenesis as cells aggregate to form the mammary anlage. Within the embryonic mammary bud, a population of epithelial cells exists that will subsequently proliferate to form a ductal tree filling the stromal compartment, and which can produce milk upon terminal differentiation after birth. Subsequently, these structures can be remodelled and returned to a basal state after weaning before regenerating in future pregnancies. The plasticity of the mammary epithelial cell, and its responsiveness to hormone receptors, facilitates this amazing biological feat, but aberrant signalling may also result in unintended consequences in the form of frequent malignancies. Reflecting this intimate connection, a considerable number of signalling pathways have been implicated in both mammary gland morphogenesis and carcinogenesis

    Wetting morphologies on randomly oriented fibers

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    We characterize the different morphologies adopted by a drop of liquid placed on two randomly oriented fibers, which is a first step toward understanding the wetting of fibrous networks. The present work reviews previous modeling for parallel and touching crossed fibers and extends it to an arbitrary orientation of the fibers characterized by the tilting angle and the minimum spacing distance. Depending on the volume of liquid, the spacing distance between fibers and the angle between the fibers, we highlight that the liquid can adopt three different equilibrium morphologies: (1) a column morphology in which the liquid spreads between the fibers, (2) a mixed morphology where a drop grows at one end of the column or (3) a single drop located at the node. We capture the different morphologies observed using an analytical model that predicts the equilibrium configuration of the liquid based on the geometry of the fibers and the volume of liquid

    Neuregulin3 alters cell fate in the epidermis and mammary gland

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    <p>Abstract</p> <p>Background</p> <p>The Neuregulin family of ligands and their receptors, the Erbb tyrosine kinases, have important roles in epidermal and mammary gland development as well as during carcinogenesis. Previously, we demonstrated that Neuregulin3 (Nrg3) is a specification signal for mammary placode formation in mice. Nrg3 is a growth factor, which binds and activates Erbb4, a receptor tyrosine kinase that regulates cell proliferation and differentiation. To understand the role of Neuregulin3 in epidermal morphogenesis, we have developed a transgenic mouse model that expresses Nrg3 throughout the basal layer (progenitor/stem cell compartment) of mouse epidermis and the outer root sheath of developing hair follicles.</p> <p>Results</p> <p>Transgenic females formed supernumerary nipples and mammary glands along and adjacent to the mammary line providing strong evidence that Nrg3 has a role in the initiation of mammary placodes along the body axis. In addition, alterations in morphogenesis and differentiation of other epidermal appendages were observed, including the hair follicles. The transgenic epidermis is hyperplastic with excessive sebaceous differentiation and shows striking similarities to mouse models in which c-Myc is activated in the basal layer including decreased expression levels of the adhesion receptors, α6-integrin and ÎČ1-integrin.</p> <p>Conclusion</p> <p>These results indicate that the epidermis is sensitive to Nrg3 signaling, and that this growth factor can regulate cell fate of pluripotent epidermal cell populations including that of the mammary gland. Nrg3 appears to act, in part, by inducing c-Myc, altering the proliferation and adhesion properties of the basal epidermis, and may promote exit from the stem cell compartment. The results we describe provide significant insight into how growth factors, such as Nrg3, regulate epidermal homeostasis by influencing the balance between stem cell renewal, lineage selection and differentiation.</p

    Late Relapse and Follow-up Protocols in Testicular Germ Cell Tumours: The Edinburgh Cancer Centre Experience and Review of the Literature

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    Aims To identify clinicopathological features and outcomes in patients with late relapse (LR) of testicular germ cell tumours (GCTs) in order to guide follow-up policy. Materials and Methods The Edinburgh Cancer Centre (ECC) database identified all patients diagnosed with testicular GCT between 1988 and 2002. Of 703 patients, six relapsed more than 24 months after their initial treatment. A retrospective casenote review was performed to extract clinical, pathological, treatment and outcome data. Results Six patients (0.85%) underwent late relapse. All patients presented initially with stage I disease and five were classified as good risk (International Germ Cell Consensus Classification, IGCCC). Median time to LR was 31 months. Two patients had previously relapsed less than 24 months from initial diagnosis. Markers at the time of relapse were normal in all patients. In all cases of late relapse disease was confined to axial lymphadenopathy. Three patients were treated with chemotherapy alone, two patients underwent surgical resection and one patient received combined treatment. All patients obtained a complete response and all remain disease free with a median follow-up of 52 months. Conclusions The incidence of late relapse in this series is low. Chemo-naive patients with LR were successfully salvaged with chemotherapy alone and patients previously exposed to cisplatin-based chemotherapy were salvaged with complete surgical excision. The optimal length of follow-up in patients with testicular germ cell tumours is not known and practice varies widely. In this cohort of 703 patients, only one patient who relapsed was picked up by additional clinic follow-up between 5 and 10 years. Thus, on the basis of this small series, the authors suggest that follow-up after five years may not be justified

    Dynamic Expression of Erbb Pathway Members during Early Mammary Gland Morphogenesis

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    Similar to other epithelial appendages, mammary anlagen progress from stratified epithelium through placode and bud stages. Embryonic mammary morphogenesis is elicited by a combination of local cell migration, adhesion changes and proliferation, and these same developmental processes impact breast cancer etiology. The Erbb signaling network plays important roles in postnatal mammary gland morphogenesis and carcinogenesis. Neuregulin3 (Nrg3), an Erbb family ligand, has recently been shown to be involved in the specification of mammary glands in mice. To further examine the possible involvement of other Erbb family members and their ligands in early mammary morphogenesis, we have characterized their expression patterns during this process. We used whole mount in situ hybridization to analyze the expression patterns of these genes at stages prior to and during mammary placode formation. Immunohistochemistry was used to examine expression patterns at later bud stages. The Neuregulin ligands, Nrg1, Nrg2, Nrg3, Nrg4 and the receptors, Erbb1, Erbb2, Erbb3, Erbb4, were expressed either at stages prior to morphological appearance of the mammary placode or from the time that the placode is first morphologically distinct through to later bud stages. The expression patterns presented here suggest that multiple members of this signaling network are potential mediators of early mammary morphogenesis

    Functional decline after incident wrist fractures—Study of Osteoporotic Fractures: prospective cohort study

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    Objective To study the effect of an incident wrist fracture on functional status in women enrolled in the Study of Osteoporotic Fractures

    European Network of Breast Development and Cancer turned 10 years: a growing family of mammary gland researchers

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    The European Network for Breast Development and Cancer (ENBDC), a worldwide network (http://www.enbdc.org/), celebrated its tenth anniversary with a fantastic meeting last March 15-17, 2018 in Weggis with 76 attendees

    Cost of post-deployment screening for mental illness in the UK military: findings from a cluster randomised controlled trial

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    Background: Little is known about the economic impact of military mental health screening. Aims: To investigate (1) whether post-deployment screening of military personnel affects use and cost of services and (2) the impact of psychiatric morbidity on costs. Methods: Participants were recruited from UK Royal Marine and Army platoons and randomised to an intervention group (which received tailored advice predicated upon mental health status) or a control group (which received general advice following assessment of mental health status). The intervention costs were calculated while service use and associated costs were assessed at 12 month follow-up. Results: Data were available for 6,323 participants. Mean screening cost was ÂŁ34. Service costs were slightly higher in the control group compared to the intervention group (ÂŁ1,197 vs. ÂŁ1,147) which was not statistically significant (bootstrapped 95% CI, -ÂŁ363 to ÂŁ434. In both groups, screening and control, costs were significantly higher for those who screened positive for mental health problems. Conclusion: Costs were not affected by screening. In countries which have already implemented post-deployment screening, the political cost of disinvestment needs careful consideration. Those who develop psychiatric morbidity have substantially higher care costs than those who do not
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