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Publications (46)
The analysis of cell motion in an acoustic field is of interest as it can lead to new methods of cell separation, isolation and manipulation for diagnosis and treatment of diseases. Studies of the motion of different species of Leishmania parasites during exposure to ultrasonic standing waves in a microfluidic device allowed identification of acous...
Particles or cells in suspension and exposed to ultrasonic waves experience an acoustic radiation force (FR) which, under certain conditions, drives them toward positions of acoustic equilibrium. In this paper, we present a three-dimensional model of the particle motions within the acoustic field generated by ultrasonic standing waves. This model a...
Outer membrane vesicles (OMV) have been proposed as exogenous antigen carriers. In order to discriminate effects associated with antigen specificity from those derived from OMV alone, the impact of their internalization on the electrical properties of macrophages was determined. The model studied was the murine macrophage-like cell line J774.A1 exp...
CLASSICAL ACTIVATION OF MACROPHAGE LIKE CELL LINE J774A.1 DURING THE
INTERNALIZATION OF OMV FROM E. coli JC8031
Electrophysiological caracgterization of leishmania amazonensis infected macrophages J774.A1
Split-flow fractionation (SPLITT) is a family of techniques that separates in the absence of labeling using very low flow rates and force fields, and is therefore expected to minimize cell damage. Although it has been documented that separation methods cause physiological changes in immune cells that are attributable to mechanical stress and antibo...
La resistencia a antimicrobianos representa un aspecto natural de evolución bacteriana, que puede resultar de mutaciones o por adquisición de genes foráneos. Hay diferentes posturas sobre el origen de ésta resistencia que explican la habilidad de estos microorganismos de adquirir nuevas características. Las teorías de la evolución de Lamarck y Darw...
Despite the significant morbidity and mortality of infectious-contagious diseases nowadays, the
alternatives for treatment and immunization are not satisfactory. For this reason, the search for
new control strategies for this group of pathologies becomes imperative. In this context, controlled
release technologies such as outer membrane vesicles (O...
In order to evaluate the physiological impact of outer membrane vesicles (OMV) obtained from E. coli JC8031, as exogenous antigen carriers, we studied the effect of the internalization of “empty” OMV (without exogenous antigens) on the electrophysiological properties of the macrophage-like cell line J774A.1 Whole cell patch-clamp recordings were us...
Outer membrane vesicles (OMV) have been proposed as exogenous antigen carriers. In order to discriminate effects associated with antigen specificity from those derived from OMV alone, the impact of their internalization on the electrical properties of macrophages was determined. The model studied was the murine macrophage‐like cell line J774.A1 exp...
The uses of ultrasounds in medical applications like ultrasonic surgery, diagnosis, and nowadays in cellular separations and manipulations, has foment the study about physical and biological effects, related to exposure of cells at an acoustic field. The interest in determining these effects could help to optimize the ultrasound uses, and identify...
p>Leishmania es un protozoario patógeno, que transita durante su ciclo de vida desde el intestino de su vector hasta un compartimiento
fagolisosomal al interior de su célula hospedera, el macrófago. Durante este recorrido el parásito está expuesto a ambientes que
cambian en temperatura, pH y presumiblemente osmolaridad. Para su supervivencia, Leish...
Though blood bank processing traditionally employs centrifugation, new separation techniques may be appealing for large scale processes. Split-flow fractionation (SPLITT) is a family of techniques that separates in absence of labelling and uses very low flow rates and force fields, and is therefore expected to minimize cell damage. However, the hyd...
Leishmania is a protozoan pathogen that transits during its lifecycle from the gut of the vector to a phagolysosomal compartment within its host cell, the macrophage. During this journey, the parasite is exposed to environments that change in temperature, pH and osmolarity. For their survival, Leishmania must make adjustments to adapt and expressio...
Betancourt, A., Maldonado, A., Maldonado, R., Camargo, A., Guzmán, A., Annicchiarico, I.,
Arroyave, J., Malagón, N., Pardo, L., Pérez, H., Ruiz, A., Eljach, L. & Camacho, M. (2002). Efectos de la inversión de la imagen en el reconocimiento de rostros [Image inversion effect on face recognition]. Acta Biológica Colombiana, 7, 53-57.
http://www.ascb.org/wp-content/uploads/2015/11/AllPosterPresentations2014.pdf
Leishmaniasis is a re-emerging tropical disease caused by parasitic protozoa of the genus Leishmania. The life cycle of this pathogen includes a mosquito vector and a vertebrate. After entry into its mammalian host, the parasite is taken up by cells of the immune system, macrophages, and confined into a low pH intra-cellular compartment known as th...
Some intracellular parasites inhabit intracellular compartments known as parasitophorous vacuoles. To maintain and amplify infection, infective forms of the parasite must exit from the host cell to infect new cells. During parasite egress, two main mechanisms have been proposed: lysis of the membranes of the parasitophorus vacuole and the plasma me...
Algunos parásitos intracelulares durante la infección en hospederos vertebrados se localizan al interior de sus células hospederas en un compartimiento intracelular rodeado por membrana denominado vacuola parasitófora. Para el sostenimiento e incremento de las infecciones causadas por estos parásitos es necesario que se dé un evento de liberación/s...
Understanding the impact of intracellular pathogens on the behavior of their host cells is key to designing new interventions. We are interested in how Leishmania alters the electrical function of the plasma membrane of the macrophage it infects. The specific question addressed here is the impact of Leishmania infection on macrophage membrane prope...
After a primary infection protocol of macrophages with Leishmania amazonensis, the percentage of infection drops as infection progresses and the uninfected population of macrophages mask the effects of infection for electrophysiological studies. In order to increase or maintain the infection percentage, we introduce an enrichment process after prim...
We studied macroscopic ion currents from macrophages and compared their patterns of behavior using classical and fractal analysis. Peak and steady state currents were measured respectively at the beginning and end of a voltage-clamp pulse. Hurst coefficients H and fractional dimensions were calculated for the current fluctuations (I
H
) during the...
Understanding the impact of intracellular pathogens on the behaviour of their host cells is key to designing new interventions. We are interested in how Leishmania alters the electrical functioning of the plasma membrane of the macrophage it infects. The specific question addressed here is whether Leishmania amazonensis infection alters the macroph...
Transport mechanisms involved in pH homeostasis are relevant for the survival of Leishmania parasites. The presence of chloride conductive pathways in Leishmania has been anticipated since anion channel inhibitors limit the proton extrusion mediated by the H+ATPase, which is the major regulator of intracellular pH in amastigotes. In this study, we...
Leishmania are intracellular parasites of macrophages, confined into compartments known as parasitophorous vacuoles. The permeability of this compartment depends on its interaction with the endocytic pathway and transport proteins present on its membrane.
The membrane permeability of the parasitophorous vacuole was studied in J774.A1-macrophage lik...
Introducción. Leishmania son parásitos intracelulares de macrófagos, confinados encompartimentos denominados vacuolas parasitóforas. La permeabilidad de este compartimentodepende de su interacción con el tráfico vesicular y transportadores presentes en su membrana.
Objetivo. En este trabajo se estudió la permeabilidad de la membrana de la vacuola...
We compared the in vitro growth of promastigotes from two Leishmania species in TC-100 and Schneider media. Leishmania (Leishmania) amazonensis replication rates were similar in both tissue culture media and reached maximum rates by 48 h. In contrast Leishmania (Viannia) braziliensis growth was significantly greater in TC-100 but maximum rates were...
La expresión heteróloga de canales iónicos en la membrana de los ovocitos de anfibio es una herramienta muy útil para la caracterización de dichos canales.
Oocytes from Xenopus laevis are commonly used as an expression system for ion channel proteins. The aim of this study was to determine whether oocytes from the Colombian native toad, Bufo marinus, could be used as an alternative expression system for ion channel protein expression and functional characterization using the two-microelectrode voltage...
La expresión en sistemas heterólogos ha sido una herramienta ampliamente utilizada enlos últimos años para el estudio funcional y estructural de proteínas. Para la carac-terización de las propiedades biofísicas de canales, bombas y transportadores engeneral su expresión en ovocitos de Xenopus laevis, ha sido fundamental. Este estudioreporta la expr...
Whole cell patch-clamp recordings were used to study the electrical properties of the macrophage-like cell line J774.1, after infection with Leishmania amazonensis. Infection induced a significant increase in cell size and membrane capacitance, suggesting that parasite invasion leads to the addition of plasma membrane to the host cell. By 24 hr aft...
The Na/K-pump or Na+/K(+)-ATPase (EC 3.6.1.37), couples the hydrolysis of ATP to the active transport of Na+ and K+ ions across the plasma membrane of virtually all animal cells. The relationship between activity of the Na+/K(+)-ATPase and the sensitivity of Schistosoma mansoni to immunological attack has been investigated. It has been observed tha...
Acetylcholinesterase (AChE) is present in the muscle and on the tegument of schistosomes. Molecular forms of schistosome AChE were examined because particular AChEs are found in tissues of distinct function elsewhere. The dimeric globular form (G2) is the only form evident in adult Schistosoma haematobium: 32% of the muscle AChE is hydrophilic and...
The blood dwelling stages of schistosomes have acetylcholinesterase (AChE) and nicotinic-like acetylcholine receptors (nAChR) on their teguments. Both AChE and nAChR are concentrated on the dorsal surface of the adult male, a major surface for nutrient uptake for the worm pair. Exposure of tegumental AChE and nAChR to acetylcholine (ACh), the natur...
A simple flow culture apparatus was designed for the short-term in vitro culture of adult schistosomes. The use of this system allowed sensitive estimation of relative rates of glucose uptake by different species of schistosome. These data suggest that in parasites maintained carefully in conditions within the physiological range of glucose concent...
Blood dwelling stages of schistosomes have acetylcholinesterase (AChE) on their teguments. As an initial step towards understanding the function of tegumental AChE, we have used specific ligand-binding assays to identify nicotinic acetylcholine receptors (nAChR) on the schistosome surface. AChR could not be detected on migratory stages using fluoro...
Acetylcholinesterase (AChE) is present in all stages of the life-cycle of schistosomes and is located in muscle and on the surface of the parasite. Metrifonate is a drug that inhibits AChE. We compared the AChEs from three schistosome species (Schistosoma mansoni, Schistosoma haematobium and Schistosoma bovis) that have different susceptibilities t...
Recibido 22 de Oct. 2007; Aceptado 16 de Jun. 2008; Publicado en línea 25 de Jul. 2008 Resumen El canal Gramicidina A es el más estudiado tanto teórica como experimentalmente. En la literatura hay abundantes trabajos sobre el potencial de fuerza media (P F M) que un catión experimenta cuando pasa a través del canal. A pesar dé esto, no ha sido posi...
Projects
Projects (3)
Charaterization of the electrophysiological properties oof potassium channels of macrophages J774.A1 during apoptotic proces
Electrophysiological characterization of leishmania amazonensis infected macrophages J744.A1
En este estudio proponemos caracterizar la permeabilidad iónica (actividad de los canales iónicos) de la membrana plasmática de macrófagos murinos (Línea celular J774.A1) y la expresión de marcadores moleculares de activación celular, durante la internalización de OMV (OMV "vacías" y OMV cargadas con antígenos de Leishmania sp.) de una cepa no-patógena de E. coli JC8031 [6]. La aproximación metodológica para el estudio funcional de la interacción macrófago-OMV de E. coli JC8031 que aquí se propone, comprende el uso de técnicas de bioquímica, inmunología, ingeniería genética y electrofisiología. Nuestra propuesta de estudio permitirá generar nuevo conocimiento para aplicarlo al desarrollo de estrategias terapéuticas (vacunas) con OMV.