Identifying and characterising PPE7 (Rv0354c) high activity binding peptides and their role in inhibiting cell invasion.

This study was aimed at characterising the PPE7 protein from the PE/PPE protein family. The presence and transcription of the rv0354c gene in the Mycobacterium tuberculosis complex was determined and the subcellular localisation of the PPE7 protein on mycobacterial membrane was confirmed by immunoelectron microscope. Two peptides were identified as having high binding activity (HABPs) and were tested in vitro regarding the invasion of Mycobacterium tuberculosis H37Rv. HABP 39224 inhibited invasion in A549 epithelial cells and U937 macrophages by more than 50%, whilst HABP 39225 inhibited invasion by 40% in U937 cells. HABP 39224, located in the protein's C-terminal region, has a completely conserved amino acid sequence in M. tuberculosis complex species and could be selected as a base peptide when designing a subunit-based, anti-tuberculosis vaccine.

Mycobacterium tuberculosis PE9 protein has high activity binding peptides which inhibit target cell invasion.

PE/PPE proteins are involved in several processes during Mycobacterium tuberculosis (Mtb) infection of target cells; studying them is extremely interesting as they are the only ones from the Mycobacterium genus, they abound in pathogenic species such as Mtb and their function remains yet unknown. The PE9 protein (Rv1088) was characterised, the rv1088 gene was identified by PCR in Mtb complex strains and its expression and localisation on mycobacterial surface was confirmed by Western blot and immunoelectron microscopy. Bioinformatics tools were used for predicting PE9 protein structural aspects and experimental study involved the circular dichroism of synthetic peptides. The peptides were tested in binding assays involving U937 and A549 cells; two high activity binding peptides (HABPs) were found for both cell lines (39226-(1)MSYMIATPAALTAAATDIDGI(21) and 39232-(125)YQRHFGTGGQPEFRQHSEHRR(144)), one for U937 (39231-(104)YAGAGRRQRRRRSGDGQWRLRQ(124)) and one for A549 (39230-(83)YGTGVFRRRRGRQTVTAAEHRA(103)). HABP 39232 inhibited mycobacterial entry to A549 cells (∼70%) and U937 cells (∼50%), peptides 39226 and 39231 inhibited entry to U937 cells (∼60% and 80%, respectively) and peptide 39230 inhibited entry to A549 cells (∼60%). This emphasised HABPs' functional importance in recognition between Mtb H37Rv and target cell receptors. These peptide sequences could be involved in invasion and were recognised by the host's immune system, thereby highlighting their use when designing an efficient anti-tuberculosis multiantigenic vaccine.

Cambios en algunas variables hematológicas, en un grupo de mujeres mayores de 55 años, luego de un programa de entrenamiento aeróbico / Changes in some hematologic variables in a group of women older Than 55 years, after a program of aerobic training

Esta investigación fue realizada con el auspicio del Comité para el desarrollo de la investigación de la Universidad de Antioquia (CODI) e Indeportes Antioquia.Objetivo: determinar los cambios en algunas variables hematológicas luego de un programa de actividad física aeróbica, por un período de cuatro meses, en un grupo de mujeres sedentarias sanas mayores de 55 años.Método: se estudiaron 14 mujeres mayores de 55 años, sedentarias, sanas, a quienes se les realizó un programa de actividad física aeróbica tres días a la semana, durante cuatro meses consecutivos, con una intensidad entre el 60 y el 85 por ciento de la FCmax y una duración de 60 minutos. Antes y después del programa de actividad física se obtuvieron muestras de sangre para evaluar el comportamiento de la hemoglobina (Hb), el hematocrito (Hct), el recuento de glóbulos rojos, el volumen corpuscular medio (VCM), la hemoglobina corpuscular media (HCM) y la concentración de hemoglobina corpuscular media (CHCM); mediante una prueba máxima, se realizó la medición del consumo máximo de oxígeno. Resultados: se observó un incremento estadísticamente significativo de la Hb (p<0.01),el Hct (p<0.01), el VCM (p<0.001), la HCM (p<0.001) y el VO2max (p<0.05). No hubo cambio en el recuento de glóbulos rojos ni en la CHCM. Conclusión: un programa de actividad física regular, a intensidades entre el 60 y el 85 por ciento de la frecuencia cardíaca máxima, en la población estudiada, incrementó los valores de la hemoglobina y del hematocrito, lo que sugiere que el entrenamiento aeróbico mejora el aporte de oxígeno hacia los tejidos.

Objective: to evaluate changes in some hematologic variables after a four-month program of aerobic physical activity, in a group of healthy women, older than 55 years. Methods: 14 healthy sedentary women, older than 55 years were studied; they participated in a program of aerobic physical activity, three times per week, during four months, with an intensity between 60-85% of the maximal heart rate and with 60 minutes of duration per session. Before and after the program blood specimens were obtained to evaluate changes of hemoglobin, hematocrite, red blood cells count, average corpuscular volume, average corpuscular hemoglobin, and average concentration of corpuscular hemoglobin; by means of a maximal test in treadmill the maximal oxygen uptake (VO2max) was determined. Results: significant increase was found in hemoglobin (p<0.01), hematocrite (p<0.001), average corpuscular volume (p<0.001), average corpuscular hemoglobin (p<0.01) and VO2max (p<0.05). There were no changes in red blood cell count and average concentration of corpuscular hemoglobin. Conclusion: in the studied group, a program of regular physical activity, with an intensity between 60-85% of the maximal heart rate, increased hemoglobin and hematocrite. This results suggest that aerobic training increases the transport of oxygen to tissues.

Segundos mensajeros / Second messengers

En esta revision se describen, de manera esquematica, los mecanismos de accion empleados por los Segundos Mensajeros comenzando por el estimulo del receptor y continuando con las reacciones en cadena que conducen finalmente a una respuesta celular.

This review schematically describes the different mechanisms of action that Second Messengers employ to stimulate receptors and then Initiate a chain of reactions that finally lead to appropriate cellular responses.