The role of estrogen in promoting mammary stem cell proliferation remains controversial. It is unclear if estrogen receptor (ER)-expressing cells have stem/progenitor activity themselves or if they act in a paracrine fashion to stimulate stem cell proliferation. We have used flow cytometry to prospectively isolate mouse mammary ER-expressing epithelial cells and shown, using analysis of gene expression patterns and cell type-specific markers, that they form a distinct luminal epithelial cell subpopulation that expresses not only the ER but also the progesterone and prolactin receptors. Furthermore, we have used an in vivo functional transplantation assay to directly demonstrate that the ER-expressing luminal epithelial subpopulation contains little in vivo stem cell activity. Rather, the mammary stem cell activity is found within the basal mammary epithelial cell population. Therefore, ER-expressing cells of the mammary epithelium are distinct from the mammary stem cell population, and the effects of estrogen on mammary stem cells are likely to be mediated indirectly. These results are important for our understanding of cellular responses to hormonal stimulation in the normal breast and in breast cancer.

BACKGROUND: COVID-19 has been causing a high burden of suffering for patients and families. There is limited evidence on the preparedness of Indian palliative care services for the pandemic. AIM: This study aimed to assess the preparedness and capacity of Indian palliative care services in response to the COVID-19 pandemic. METHODS: A cross-sectional online survey was developed based on prior evidence and international health regulations. It was emailed to the Indian Palliative Care Association members and investigators professional networks in India. One participant per palliative care service was requested. Descriptive analysis was used. RESULTS: Representatives of 78 palliative care services completed the survey. Three in four services had COVID-19 case definition and adapted their protocols for infection control (75%). About half of the services (55%) reported concerns about achieving appropriate hand hygiene in the community. More than half of the services (59%) had capacity to train nonspecialists for symptom control and psychological support. About half of the services reported that they had plans to redeploy staff (56%) and resources (53%) in the case of outbreaks. Two-fifths of the services used paper records to store an updated contact list of staff (40%) and did not have designated focal contacts for information update (40%). Staff anxiety related to personal infection risk and family care was relatively high (median score = 7 on a 1-10 scale). CONCLUSION: We recommend the following resource allocation to enable palliative care services to support the Indian health system in delivering essential care in this and future pandemics: (1) infection control, especially in the community; (2) training using existing clinical protocols to strengthen palliative care across the health system; and (3) redeployment plans.