Avaliação da autoeficácia materna em amamentar no puerpério imediato / Assessment of maternal self-efficacy in breastfeeding in the immediate puerperium

Objetivo: avaliar a autoeficácia materna em amamentar no puerpério imediato. Métodos: estudo transversal que envolveu 132 puérperas. No alojamento conjunto, foi aplicado formulário com dados sociodemográficos e obstétricos e a Breastfeeding Self-Efficacy Scale ­ Short Form. Resultados: a maioria das mulheres entrevistadas apresentou elevada (90,9%) e média (9,1%) autoeficácia em amamentar. Não houve associação entre os escores da Breastfeeding Self-Efficacy Scale ­ Short Form e as variáveis sociodemográficas e obstétricas. Conclusão: as mulheres apresentaram elevada autoeficácia em amamentar, o que remete à expectativa favorável ao aleitamento materno, sendo necessário acompanhamento do profissional enfermeiro para garantir assistência mais efetiva no apoio à amamentação (AU).

Computational protein design: the Proteus software and selected applications.

We describe an automated procedure for protein design, implemented in a flexible software package, called Proteus. System setup and calculation of an energy matrix are done with the XPLOR modeling program and its sophisticated command language, supporting several force fields and solvent models. A second program provides algorithms to search sequence space. It allows a decomposition of the system into groups, which can be combined in different ways in the energy function, for both positive and negative design. The whole procedure can be controlled by editing 2-4 scripts. Two applications consider the tyrosyl-tRNA synthetase enzyme and its successful redesign to bind both O-methyl-tyrosine and D-tyrosine. For the latter, we present Monte Carlo simulations where the D-tyrosine concentration is gradually increased, displacing L-tyrosine from the binding pocket and yielding the binding free energy difference, in good agreement with experiment. Complete redesign of the Crk SH3 domain is presented. The top 10000 sequences are all assigned to the correct fold by the SUPERFAMILY library of Hidden Markov Models. Finally, we report the acid/base behavior of the SNase protein. Sidechain protonation is treated as a form of mutation; it is then straightforward to perform constant-pH Monte Carlo simulations, which yield good agreement with experiment. Overall, the software can be used for a wide range of application, producing not only native-like sequences but also thermodynamic properties with errors that appear comparable to other current software packages.

Universal positions in globular proteins.

The description of globular protein structures as an ensemble of contiguous 'closed loops' or 'tightened end fragments' reveals fold elements crucial for the formation of stable structures and for navigating the very process of protein folding. These are the ends of the loops, which are spatially close to each other but are situated apart in the polypeptide chain by 25-30 residues. They also correlate with the locations of highly conserved hydrophobic residues (referred to as topohydrophobic), in a structural alignment of the members of a protein family. This study analysed these positions in 111 representatives of different protein folds, and then carried out dynamic Monte Carlo simulations of the first steps of the folding process, aimed at predicting the origins of the assembling folds. The simulations demonstrated that there is an obvious trend for certain sets of residues, named 'mostly interacting residues', to be buried at the early stages of the folding process. Location of these residues at the loop ends and correlation with topohydrophobic positions are demonstrated, thereby giving a route to simulations of the protein folding process.