We examined breast milk for rotavirus-specific IgA and neutralizing activity against 3 rotavirus vaccine strains-RV1, RV5 G1,
and 116E using enzyme immunoassays. The inhibitory effect of breast milk on RV1 was further examined by a plaque reduction assay.
Findings: Breast milk from Indian women had the highest IgA and neutralizing titers against all 3 vaccine strains, while lower but comparable median IgA and neutralizing titers were detected in breast milk from Korean and Vietnamese women, and the lowest titers were seen in American women. Neutralizing activity was greatest against the 2 vaccine strains of human origin, RV1 and 116E. This neutralizing learn more activity in one half of the breast milk specimens from Indian women could reduce the effective titer of RV1 by similar to 2 logs, of 116E by 1.5 logs, and RV5 G1 strain by similar to 1 log more than that of breast milk from American women.
Interpretation: The lower immunogenicity and efficacy of rotavirus vaccines in poor developing countries could be explained, in part, by higher titers of IgA and neutralizing activity in breast milk consumed by their
infants at the time of immunization that could effectively reduce the potency of the vaccine. Strategies to overcome this negative effect, such as delaying breast-feeding at the time of immunization, should be evaluated.”
“Self-diffusion was studied in magnetron sputtered nitrogen-rich amorphous compounds of the system Si-C-N by using Selleck Panobinostat nitrogen as a model tracer. As shown by infra-red spectroscopy a transient metastable region exists, where the structure of the
material can be visualized as silicon nitride tetrahedra which are connected by carbo-diimide (-N=C=N-) bonds to a three dimensional amorphous network. In this region diffusion studies are carried out by neutron reflectometry and isotope multilayers as a function of annealing time, temperature and chemical composition. Low diffusivities between 10(-20) and 10(-24) m(2)/s were found. In the metastable selleck products region, diffusion is faster than diffusion in amorphous silicon nitride by 1 to 2 orders of magnitude, while the activation enthalpies of diffusion between 3.1 and 3.4 eV are the same within error limits. This can be explained by the fact that the diffusion mechanism along SiN(4) tetrahedra is identical to that in amorphous silicon nitride, however, the carbo-diimide bonds seem to widen the structure, allowing faster diffusion. A correlation between diffusivities and the number of carbo-diimid bonds present in the material is found, where the highest diffusivities are observed for materials with the highest number of carbo-diimid bonds, close to the composition Si(2)CN(4). (C) 2011 American Institute of Physics. [doi:10.1063/1.