Osteoinduction in the palatal submucosa by injecting BMP-2 on 2 different carriers

In this work, we investigated the ability of injected recombinant human bone morphogenetic protein 2 (rhBMP-2) on brushite cement (a β-tricalcium phosphate-based biomaterial) and collagen gel as carriers to induce osteogenic differentiation in the palatal submucosa of 10-day-old rats. This was part of a broader study aiming to create bone in the palatal submucosa at cleft palate edges in the search for a minimally invasive treatment. Thirteen treated animals, 7 with rhBMP-2/brushite cement and 6 with rhBMP-2/collagen gel, were injected with 5 to 10 μL of each biomaterial in the right palatal submucosa at the level between the second and third rugae. The contralateral site was uninjected and served as the control. Six weeks after injection, both brushite cement and collagen gel were histologically unrecognizable in all treated animals. New bone structures such as ossicles of woven bone were not detected. However, an augmentation in the thickness of the palatal fibromucosa was observed at the injection site of all palates. In addition, immunolabeling for osteopontin, proliferating cell nuclear antigen, and TUNEL revealed intense osteogenic induction at the injection site with both constructs, which was negative in the control site from the same specimens; no differences regarding cell proliferation and death were observed. The present study confirms the feasibility of generating osteogenic cells in the palatal submucosa by injecting low doses of rhBMP-2 in these 2 biomaterials, together with their inability to form bone.     

Immune responses to measles and mumps vaccination of infants at 6, 9, and 12 months

Immunizing infants against measles at the youngest age possible has the potential to reduce morbidity and mortality. The ability of infants at 6, 9, or 12 months to respond to measles and mumps vaccines was evaluated by measuring T cell proliferation, interferon-gamma production, and neutralizing antibody titers before and after vaccination. Infants in all age groups had equivalent cellular immune responses to measles or mumps viruses, with or without passive antibodies when immunized. In contrast, 6-month-old infants without passive antibodies had low geometric mean titers of antibody to measles or mumps viruses and low seroconversion rates. Geometric mean titers of antibody to measles virus increased if infants were revaccinated at 12 months. Six-month-old infants had limited humoral responses to paramyxovirus vaccines, whereas cellular immunity was equivalent to that of older infants. T cell responses can be established by immunization with these live attenuated virus vaccines during the first year, despite the presence of passive antibodies.