Maternal sociodemographic characteristics and the use of the Iowa Infant Attitude Feeding Scale to describe breastfeeding initiation and duration in a population of urban,Latina mothers: a prospective cohort study

Background

The World Health Organization recommends exclusive breastfeeding until 6 months of age. Maternal attitudes toward infant feeding are correlated with chosen feeding method and breastfeeding duration. The Iowa Infant Feeding Attitude Scale (IIFAS) has been used to assess attitudes towards breastfeeding prenatally and is predictive of breastfeeding decisions in certain population groups.

Methods

In a cohort of pregnant Latina women recruited from two hospitals in the San Francisco Bay Area (n=185), we administered the IIFAS prior to delivery. Information regarding feeding choice, maternal sociodemographic information, and anthropometrics were collected at 6 months and 1 year postpartum. Analysis of predictors for breastfeeding initiation, breastfeeding at 6 and 12 months and exclusive breastfeeding at 6 months were evaluated using multivariate logistic regression adjusting for potential confounders.

Results

In our cohort of Latina mothers, breastfeeding a previous infant was associated with breastfeeding initiation (OR 8.29 [95% CI 1.00, 68.40] p = 0.05) and breastfeeding at 6 months (OR 18.34 [95% CI 2.01, 167.24] p = 0.01). College education was associated with increased exclusive breastfeeding at 6 months (OR 58.67 [95% CI 4.97, 692.08] p = 0.001) and having other children was associated with reduced breastfeeding at six months (OR 0.08 [95% CI 0.01, 0.70] p = 0.02). A higher IIFAS score was not associated with breastfeeding initiation, breastfeeding at 6 or 12 months or exclusive breastfeeding at 6 months of age.

Conclusions

Initial choices about breastfeeding will likely influence future breastfeeding decisions, so breastfeeding interventions should specifically target new mothers. Mothers with other children also need additional encouragement to maintain breastfeeding until 6 months of age. The IIFAS, while predictive of breastfeeding decisions in other population groups, was not associated with feeding decisions in our population of Latina mothers.

     

Antigenic and Immunogenic Characteristics of Nuclear and Membrane-Associated Simian Virus 40 Tumor Antigen

Antisera were prepared in syngeneic hosts against subcellular fractions of simian virus 40 (SV40)-transformed cells (MoalphaPM, MoalphaNuc), glutaraldehydefixed SV40-transformed cells (HaalphaH-50-G, MoalphaVLM-G), and electrophoretically purified denatured SV40 tumor antigen (T-ag) (RaalphaT). Immune sera were also collected from animals bearing tumors induced by SV40-transformed cells (HaalphaT, MoalphaT, HAF) and from SV40-immunized animals that had rejected a transplant of SV40-transformed cells (HaalphaS, MoalphaS). Immunological reagents prepared against cell surface (MoalphaPM, HaalphaS, MoalphaS, HaalphaH-50-G, MoalphaVLM-G) reacted exclusively with the surface of SV40-transformed cells by indirect immunofluorescence or protein A surface antigen radioimmunoassay. Immunological reagents prepared against the nuclear fraction (MoalphaNuc) or whole-cell determinants (HaalphaT, MoalphaT, HAF, RaalphaT) reacted with both the nuclei and surface of SV40-transformed or -infected cells. All reagents were capable of immunoprecipitating 96,000-molecular weight large T-ag from solubilized whole cell extracts of SV40-transformed cells. The exclusive surface reactivity of HaalphaS exhibited in immunofluorescence tests was abolished by solubilization of subcellular fractions, which then allowed immunoprecipitation of T-ag by HaalphaS from both nuclear and plasma membrane preparations. Specificity was established by the fact that all T-reactive reagents failed to react in serological tests against chemically transformed mouse cells, and sera from mice bearing transplants chemically transformed mouse cells (MoalphaDMBA-2) failed to react with SV40-transformed mouse or hamster cells. Reagents demonstrating positive surface immunofluorescence and protein A radioimmunoassay reactions against SV40-transformed cells were capable of blocking the surface binding of RaalphaT to SV40-transformed cells in a double-antibody surface antigen radioimmunoassay. This blocking ability demonstrated directly that a component specificity of each surface-reactive reagent is directed against SV40 T-ag. A model is presented which postulates that the differential detection of T-ag by the various serological reagents is a reflection of immunogenic and antigenic differences between T-ag polypeptides localized in nuclei and plasma membranes.     

Retargeting of coronavirus by substitution of the spike glycoprotein ectodomain: crossing the host cell species barrier

Coronaviruses generally have a narrow host range, infecting one or just a few species. Using targeted RNA recombination, we constructed a mutant of the coronavirus mouse hepatitis virus (MHV) in which the ectodomain of the spike glycoprotein (S) was replaced with the highly divergent ectodomain of the S protein of feline infectious peritonitis virus. The resulting chimeric virus, designated fMHV, acquired the ability to infect feline cells and simultaneously lost the ability to infect murine cells in tissue culture. This reciprocal switch of species specificity strongly supports the notion that coronavirus host cell range is determined primarily at the level of interactions between the S protein and the virus receptor. The isolation of fMHV allowed the localization of the region responsible for S protein incorporation into virions to the carboxy-terminal 64 of the 1,324 residues of this protein. This establishes a basis for further definition of elements involved in virion assembly. In addition, fMHV is potentially the ideal recipient virus for carrying out reverse genetics of MHV by targeted RNA recombination, since it presents the possibility of selecting recombinants, no matter how defective, that have regained the ability to replicate in murine cells.     

Antioxidant protein 2 prevents methemoglobin formation in erythrocyte hemolysates.

Antioxidant protein 2 (AOP2) is a member of a family of thiol-specific antioxidants, recently renamed peroxiredoxins, that evolved as part of an elaborate system to counteract and control detrimental effects of oxygen radicals. AOP2 is found in endothelial cells, erythrocytes, monocytes, T and B cells, but not in granulocytes. AOP2 was found solely in the cytoplasm and was not associated with the nuclear or membrane fractions; neither was it detectable in plasma. Further experiments focused on the function of AOP2 in erythrocytes where it is closely associated with the hemoglobin complex, particularly with the heme. An investigation of the mechanism of this interaction demonstrated that the conserved cysteine-47 in AOP2 seems to play a role in AOP2-heme interactions. Recombinant AOP2 prevented induced as well as noninduced methemoglobin formation in erythrocyte hemolysates, indicating its antioxidant properties. We conclude that AOP2 is part of a sophisticated system developed to protect and support erythrocytes in their many physiological functions.