Introduction: Evaluate the association between the thumb adductor muscle thickness and the patient's nutritional status, and propose cutoff points for muscle mass depletion in elderly patients with chronic kidney disease (CKD) under conservative treatment. Epidemiological and cross-sectional study, including patients with CKD stages 3 to 5, older than 60 years. Socioeconomic, clinical, physical activity and anthropometric data was obtained. TAMT was described and compared according to CKD stage, socioeconomic data, physical activity, nutritional status and correlated with age, glomerular filtration rate and anthropometric variables. Receiver Operating Characteristic (ROC) curves were produced, considering the lean tissue index classification as reference. The cut-off point was defined by the Youden index. Results: We evaluated 137 individuals. The TAMT was lower in malnourished and/or depleted muscle mass individuals; among males it was higher among those who practiced physical activities (p <0.05). This measure was moderately correlated with BMI, calf and brachial circumferences, lean body tissue, lean tissue index and body cell mass (r <0.7); negatively with age (r = -0.34). The ROC curve analysis determined cut points of 15.33 mm for females and 20.33 mm for males, with 72.22% and 62.50% accuracy, respectively. Conclusion: TAMT is used to estimate muscle mass and we suggest the cutoff point is useful to rule out the likelihood of muscle mass depletion. It is recommended that it be used in a complementary way in nutritional assessment.

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Over recent decades, multidrug-resistant pathogens have become a global concern, with WHO even considering it one of the biggest threats to global health, food security, and development today, which led to the search for alternative antibacterial agents. A special class is formed by peptides composed by the diphenylalanine motif whose antibacterial properties result from their supramolecular arrangement into nanotubes. However, several other dipeptides that also form nanotubes have been largely overlooked. Here, we present the antibacterial activity of four dipeptide nanotubes. The results point to diverse mechanisms through which dipeptide nanotubes exert their effect against bacteria. Antibacterial activity was similar for dipeptide nanotubes sufficiently wide to allow water flux while dipeptides displaying smaller channels were inactive. This suggests that two of the tested dipeptides, L-Phe-L-Phe (FF, diphenylalanine) and L-Leu-L-Ser (LS), are pore forming structures able to induce membrane permeation and affect cellular hydration and integrity. Of these two dipeptides, only FF demonstrated potential to inhibit biofilm formation. The amyloid-like nature and hydrophobicity of diphenylalanine assemblies are probably responsible for their adhesion to cell surfaces preventing biofilm formation and bacteria attachment.

The aim of this study was to evaluate the concordance between adductor pollicis muscle thickness (APMT) measured by ultrasonography and adipometer and the applicability of the measurement as an indicator of the nutritional status of patients with chronic kidney disease (CKD). Methods: Epidemiological study with a cross-sectional design (n= 137). The concordance between APMT assessed by both methods were evaluated by intraclass correlation coefficient. Bland-Altman graphics were produced. APMTs were correlated with body mass index (BMI); calf circumference (CC), brachial circumference (BC) and brachial muscle (BMC); lean tissue mass (LTM); LTM index and body cell mass (BCM) via Pearson correlation. The adipometer overestimated APMT by 7 mm when compared to ultrasonography. APMT measured by adipometer was moderately correlated with BMI, CC, BC, BMC, LTM and BCM. APMT by ultrasonography was weakly correlated with CC, BMC, LTM, and LTM index. Conclusion: APMT presented weak or moderate correlation between methods. The measurement was predictive of muscle mass. We suggest that APMT be used in a complementary way in the evaluation of body composition.