Immunodeficiency in RFM/(T6xRFM)F1 mouse chimaeras with lethal host-versus-graft syndrome.

Rather than central tolerance, the perinatal inoculation of related F1 hybrid spleen cells into inbred mice may result in host-versus-graft (HVG) reactions manifested as transient autoimmunity, or as a lethal immunodeficiency syndrome. RFM/(T6xRFM)F1 chimaeras with lethal disease die in 30 days with lymphosplenomegaly, immune complexes and impaired immune responses. The present studies used in vitro proliferation assays to show that the HVG reaction caused hyperplasia sufficient to account for the lymphosplenomegaly, while also causing severe impairment of splenic and nodal cell responses to concanavalin A (Con A) and to bacterial lipopolysaccharide (LPS). By 25 days, HVG mice could not distinguish between self and non-self as judged by mixed lymphocyte reactions (MLR) to RFM, (T6xRFM)F1 and third party A/J cells. There were no indications that host cells reactive to F1 donor cells had undergone clonal deletion, anergy or expansion. Flow cytometry revealed that donor T lymphocytes achieved stable engraftment, mostly in the nodes, despite the HVG reaction. Taken together with previous observations, these studies showed that HVG reactions in young parent F1/chimaeras can result in an immunodeficiency state which is characterized by an early appearing, profound and persistent impairment of both host and donor T and B cell functions. The results suggest that HVG reactions can contribute directly to immune deficits seen after clinical allogeneic bone marrow transplantation.     

Identification of Barriers and Facilitators of Healthy Food Choices Among Children Aged 6 to 12 Years: From the Kahnawake Schools Diabetes Prevention Project

This study aimed to identify barriers and facilitators of healthy food choices among children aged 6 to 12 years in Kahnawake, and help orienting Kahnawake School Diabetes Prevention Project (KSDPP) to improve the diet of the children. A series of four focus groups with a total of 15 people was conducted with mothers of children enrolled in one of the two intervention schools. Comments were analyzed verbatim by content analysis.

Results showed that cost, time, taste, season of the year, pressure from family and friends, and health concerns within the family can be both barriers and facilitators of healthy eating for the children. However, KSDPP is a facilitator.