[Autopercepción del peso a través de figuras corporales en niños en edad escolar de Piedras Negras, Coahuila, México]

Background

The prevalence of overweight and obesity has increased worldwide. In this context, the lack of awareness of excess weight among overweight and obese children is a public health concern that needs to be explored in the Northern border of Mexico.

Methods

Body mass index (BMI) was calculated from children from third to sixth grades of basic education. The Children's Body Image Scale was applied to evaluate perceived and ideal BMI comparing against calculated BMI. We also analyzed the frequency of accurate perceivers of actual weight and discrepancy of ideal weight against calculated BMI.

Results

We studied 155 children (43.8% were female) with a mean age of 10.2 years. Accuracy prevalence of BMI perceived respect to calculated BMI was 59.4%. Discrepancy prevalence of ideal BMI respect to calculated BMI was 44.4%. Comparison of perceived BMI respect to calculated BMI showed an overestimation on low weight category (33%) and subestimations in categories of normal weight (12.4%), overweight (85%) and obesity (81.6%). Comparison of ideal BMI respect to calculated BMI showed an absolute overestimation of low weight and underestimations in categories of normal weight, overweight and obesity of 5.6%, 100%, and 97.4%, respectively.

Conclusions

The results of this work showed a consistent underestimation of children's body weight, particularly among those classified in categories of overweight and obesity in a demographic context in which the prevalence of both categories was of 38% in this study.

In vitro and in vivo antimicrobial activity of a synthetic peptide derived from the C-terminal region of human chemokine CCL13 against Pseudomonas aeruginosa

Chemokines are important mediators of immunological responses during inflammation and under steady-state conditions. In addition to regulating cell migration, some chemotactic cytokines have direct effects on bacteria. Here, we characterized the antibacterial ability of the synthetic oligopeptide CCL13_57-75, which corresponds to the carboxyl-terminal region of the human chemokine CCL13. In vitro measurements indicated that CCL13_57-75 disrupts the cell membrane of Pseudomonas aeruginosa through a mechanism coupled to an unordered-helicoidal conformational transition. In a murine pneumonic model, CCL13_57-75 improved mouse survival and bacterial clearance and decreased neutrophil recruitment, proinflammatory cytokines and lung pathology compared with that observed in untreated infected animals. Overall, our study supports the ability of chemokines and/or chemokine-derived oligopeptides to act as direct defense agents against pathogenic bacteria and suggests their potential use as alternative antibiotics.

Structural and thermodynamic folding characterization of triosephosphate isomerases from Trichomonas vaginalis reveals the role of destabilizing mutations following gene duplication

We report the structures and thermodynamic analysis of the unfolding of two triosephosphate isomerases (TvTIM1 and TvTIM2) from Trichomonas vaginalis. Both isoforms differ by the character of four amino acids: E/Q 18, I/V 24, I/V 45, and P/A 239. Despite the high sequence and structural similarities between both isoforms, they display substantial differences in their stabilities. TvTIM1 (E18, I24, I45, and P239) is more stable and less dissociable than TvTIM2 (Q18, V24, V45, and A239). We postulate that the identities of residues 24 and 45 are responsible for the differences in monomer stability and dimer dissociability, respectively. The structural difference between both amino acids is one methyl group. In TvTIMs, residue 24 is involved in packing α-helix 1 against α-helix 2 of each monomer and residue 45 is located at the center of the dimer interface forming a "ball and socket" interplay with a hydrophobic cavity. The mutation of valine at position 45 for an alanine in TvTIM2 produces a protein that migrates as a monomer by gel filtration. A comparison with known TIM structures indicates that this kind of interplay is a conserved feature that stabilizes dimeric TIM structures. In addition, TvTIMs are located in the cytoplasm and in the membrane. As TvTIM2 is an easily dissociable dimer, the dual localization of TvTIMs may be related to the acquisition of a moonlighting activity of monomeric TvTIM2. To our knowledge, this is the simplest example of how a single amino acid substitution can provide alternative function to a TIM barrel protein.