Aptamers as a promising approach for the control of parasitic diseases

ABSTRACT Aptamers are short single-stranded RNA or DNA oligonucleotides that are capable of binding various biological targets with high affinity and specificity. Their identification initially relies on a molecular process named SELEX (Systematic Evolution of Ligands by EXponential enrichment) that has been later modified in order to improve aptamer sensitivity, minimize duration and cost of the assay, as well as increase target types. Several biochemical modifications can help to enhance aptamer stability without affecting significantly target interaction. As a result, aptamers have generated a large interest as promising tools to compete with monoclonal antibodies for detection and inhibition of specific markers of human diseases. One aptamer-based drug is currently authorized and several others are being clinically evaluated. Despite advances in the knowledge of parasite biology and host-parasite interactions from "omics" data, protozoan parasites still affect millions of people around the world and there is an urgent need for drug target discovery and novel therapeutic concepts. In this context, aptamers represent promising tools for pathogen identification and control. Recent studies have reported the identification of "aptasensors" for parasite diagnosis, and "intramers" targeting intracellular proteins. Here we discuss various strategies that have been employed for intracellular expression of aptamers and expansion of their possible application, and propose that they may be suitable for the clinical use of aptamers in parasitic infections.

Effect of ultrasound on survival and growth of Escherichia coli in cactus pear juice during storage

Abstract The aim of this study was to investigate the effectiveness of ultrasound as a conservation method for the inactivation of Escherichia coli inoculated into cactus pear juices (green and purple). Total soluble solids, pH, titratable acidity, and the kinetics of E. coli in cactus pear juices treated by ultrasound (60%, 70%, 80% and 90% amplitude levels for 1, 3 and 5 min) were evaluated over 5 days. Total inactivation was observed in both fruit juices after 5 min of ultrasound treatment at most amplitude levels (with the exception of 60% and 80%). After one and two days of storage, the recovery of bacteria counts was observed in all cactus pear juices. Ultrasound treatment at 90% amplitude for 5 min resulted in non-detectable levels of E. coli in cactus pear juice for 2 days. The parameters of pH, titratable acidity and soluble solids were unaffected.

Obesidad infantil y su relación con indicadores cardiopulmonares en escolares mexicanos / Childhood Obesity and its Relation to Cardiopulmonary Indicators in Mexican School Children / Obesidade infantil e sua relação com indicadores cardiopulmonares em estudantes mexicanos

Objetivo: determinar la relación entre obesidad y anormalidades de parámetros cardiopulmonares en escolares. Materiales y métodos: participaron 78 escolares entre 5 a 11 años de edad, 47 hombres (60,3%) y 31 mujeres (39,7%), pertenecientes a una escuela primaria particular de la ciudad de Pachuca (México). Se evaluó: índice de masa corporal (IMC), circunferencia de cintura (CC), grasa corporal (GC), frecuencia cardiaca (FC), presión arterial (PA), frecuencia respiratoria (FR) y espirometría. Se emplearon las pruebas estadísticas chi-cuadrado (x2), odds ratio y correlación de Spearman (rs). Resultados: 23,1% de los escolares evaluados presentaron sobrepeso y 29,5%, obesidad. El 38,5 y 11,5% presentaron FC y PA superiores a los parámetros normales, respectivamente; 3,8% de la población presentó FR arriba del promedio y 11,5% mostró valores espirométricos anormales. Se encontraron relaciones entre IMC con GC y CC, GC y CC, CC y FC, GC y PA, y FC y FR. Conclusiones: las prevalencias de sobrepeso y obesidad obtenidas en este estudio fueron altas. Los niños con sobrepeso u obesidad podrían tener mayor riesgo de presentar anormalidades cardiopulmonares en comparación con niños de peso normal. Se sugiere continuar con estudios en el tema en una muestra más amplia.

Objective: Determine the relationship between obesity and abnormal cardiopulmonary parameters in school children. Materials and Methods: The sample involved 78 children between five and 11 years of age: 47 males (60.3%) and 31 females (39.7%). All were enrolled in a specific elementary school in the city of Pachuca (Mexico). Body mass (BMI), waist circumference (WC), body fat (GC), heart rate (HR), blood pressure (BP), respiratory rate (RR) and spirometry were evaluated. A chi-square (x2) statistical test, the odds ratio and Spearman's rank-order correlation (rs) were used. Results: In all, 23.1% of the students who were evaluated were overweight and 29.5% were obese; 38.5% and 11.5% had a HR and BP above the normal parameters, in that order; 3.8% of the population in question had a HR above average and 11.5% showed abnormal spirometric values. A relationship was found between BMI and BF and WC, BF and WC, WC and HR, BF and BP, and HR and RF. Conclusions: The prevalence of overweight and obesity found in this study was high. Children who are overweight or obese might be at increased risk of experiencing cardiopulmonary abnormalities compared to children of normal weight. It is suggested that studies on this subject be continued with a broader sample.

Objetivo: determinar a relação entre obesidade e anormalidades de parâmetros cardiopulmonares em estudantes do ensino fundamental. Materiais e métodos: participaram do estudo 78 estudantes entre 5 a 11 anos de idade, 47 do gênero masculino (60,3%) e 31 do feminino (39,7%), pertencentes a uma escola primária particular da cidade de Pachuca (México). Avaliaram-se o índice de massa corporal (IMC), a circunferência de cintura (CC), a gordura corporal (GC), a frequência cardíaca (FC), a pressão arterial (PA), a frequência respiratória (FR) e a espirometria. Utilizaram-se os testes estatísticos qui-quadrado (x2), odds ratio e correlação de Spearman (rs). Resultados: 23,1%o dos estudantes avaliados apresentaram excesso de peso e 29,5% obesidade. 38,5 e 11,5% apresentaram FC e PA superiores aos parâmetros normais, respectivamente; 3,8% da população apresentou FR acima da média e 11,5% mostraram parâmetros espirométricos anormais. Constataram-se relações entre IMC com GC e CC, GC e CC, CC e FC, GC e PA, e FC e FR. Conclusões: as prevalências de excesso de peso e obesidade obtidas neste estudo foram altas. As crianças com excesso de peso ou obesidade poderiam ter maior risco de apresentar anormalidades cardiopulmonares em comparação às de peso normal. Sugere-se continuar com estudos sobre o tema com uma amostra mais ampla.