Bovine mammary stem cells: new perspective for dairy science

Mammary stem cells provide for net growth, renewal and turnover of mammary epithelial cells, and are therefore potential targets for strategies to increase production efficiency. Appropriate regulation of mammary stem cells can potentially benefit milk yield, persistency, dry period management and tissue repair. Accordingly, we and others have attempted to characterize and alter the function of bovine mammary stem cells. However, research on mammary stem cells requires tissue biopsies which limit the quantity of samples available. Interestingly, different studies reported recently the identification of putative mammary stem cells in human breast milk and new data are available in ruminants for this issue. In this review we summarized the main achievements in this field for dairy cow science and describe the interesting perspectives open to manipulate milk persistency during lactation and to cope with oxidative stress during the transition period. The exciting possibility that stem cell expansion can influence milk production is currently under investigation. The identification of primitive cell types within cow’s milk may provide a non-invasive source of relevant mammary cells for a wide-range of applications

“Double culturedness”: the “capital” of Inuit nurses

Background. The health and educational systems in Greenland and Nunavut are reflections of those in Denmark and Southern Canada, with the language of instruction and practise being Danish and English. This places specific demands on Inuit studying nursing. Objective. This paper discusses the experiences of Inuit who are educated in nursing programmes and practise in healthcare systems located in the Arctic but dominated by EuroCanadian and Danish culture and language. Design. Research was qualitative and ethnographic. It was conducted through 12 months of fieldwork in 5 Greenlandic and 2 Nunavut communities. Methods. Observation, participant observation, interviews, questionnaires and document review were used. The analytical framework involved Bourdieu’s concepts of capital and habitus. Results. Participants experienced degrees of success and well-being in the educational systems that are afforded to few other Canadian and Greenlandic Inuit. This success appeared to be based on nurses and students possessing, or having acquired, what I call “double culturedness”; this makes them able to communicate in at least 2 languages and cultures, including the ability to understand, negotiate and interact, using at least 2 ways of being in the world and 2 ways of learning and teaching. Conclusion. There continues to be a critical need for Inuit nurses with their special knowledge and abilities in the healthcare systems of the Arctic. Inuit nurses’ experiences will help inform the education and healthcare systems and point to areas in need of support and change in order to increase recruitment and retention of nursing students and practitioners

Subclass distribution of natural salivary IgA antibodies against pneumococcal capsular polysaccharide of type 14 and pneumococcal surface adhesin A (PsaA) in children

A number of studies have shown that the ratio of IgA1 and IgA2 subclasses in secretions can depend upon the nature of the antigen inducing their production. In order to evaluate the effect of the nature of the antigen on the subclass distribution of the naturally occurring salivary IgA antibodies against Streptococcus pneumoniae, we used enzyme immunoassay to measure the levels of natural IgA, IgA1 and IgA2 antibodies to pneumococcal capsular polysaccharide type 14 (PS14) and pneumococcal surface adhesin A (PsaA) in saliva of children during their first 2 years of life. The sum of anti-PS14 and anti-PsaA IgA1 and IgA2 correlated significantly with the antigen-specific total IgA, which showed that IgA1 and IgA2 add up to IgA. IgA1 was the predominant subclass for both antigens. The median of anti-PS14 and anti-PsaA IgA1 was higher than that of IgA2, and the antigen-specific IgA1 was found in a larger proportion of samples than IgA2. The ratio of IgA1 to IgA2 (IgA1/IgA2 ratio) was lower for anti-PS14 than for anti-PsaA, suggesting that the PS antigen induced more IgA2 than the protein antigen. The possible impact of the IgA subclass distribution on protection of mucosal surfaces by natural or vaccine-induced antibodies needs to be determined