Browsing by Autor "Ana Lugo de Yarbuh"

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Alteraciones en la microvasculatura y unión neuromuscular del músculo esquelético Gastrocnemius de ratones con infección experimental de Chagas agudo
(2006) Ana Lugo de Yarbuh; Cesare Colasante; Maritza Alarcón; Elio Moreno
A light and transmission electron microscopy study was performed in skeletal muscles (SM) Gastrocnemius (G) from mice experimentally infected with Trypanosoma cruzi to determine changes on microvessels (MV) and neuromuscular junction (NMJ) of G. In this study 10 male (mus musculus) (20 g) were infected subcutaneally with 1.10􀀀 bloodstream trypomastigotes M/DID/Ve/02/DSM strain. Five mice were kept as uninfected controls. The parasites induced a complete paralysis of the rear limbs and death while still in the acute Chagas´disease. The histopathology of SM showed inflammatory cell infiltration by mononuclear and polymorphonuclear leukocytes associated with marked parasitism in the muscle fibers of G. Indirect immunofluorescence revealed interstitial IgG deposit as bands regularly spaced along the nerve terminals at 40 days postinfection (pi). At this time T. cruzi antigens and intracellular amastigotes nests were also observed. The marked inflammatory response and morphological changes in the SM were confirmed by transmission electron microscopy. Capillary ultrastructure was seen to be altered, with points of cell cytoplasm discontinuity that appear to represent holes in the microvessel walls. This finding coincided with amastigote nests in myofibers, close contacts between trypomastigotes and endothelial cells and marked thickening of the basement membrane of the muscle vessels. Loss of capillary lumen and a process of ischemia also were observed in the SM of infected mice. The neuromuscular junction showed degeneration of intramuscular nerve fibers, reduction in the axon caliber, swollen mitochondrial, increase in the actin filaments and microtubules in the axoplasm, and swelling of the Schwann cells. Increase in the nerve terminal perimeter and most of the synaptic vesicles were localized near the presynaptic active zones and scarces in the axoplasm. At this stage of infection the changes findings in MV and NMJ of G infected with T. cruzi, as well as ischemia and alterations in the presynaptic membrane densities in the active zones, shows that the abnormal mice NMJ is associated with an activity dependent modulation of the neurotransmission, producing abnormal motor activity and paralysis of the rear limbs mice while still in the acute Chagas´disease.
Atomic Force Microscopy of host cell-amastigote interaction in cutaneous leishmaniasis
(2004) Ana Lugo de Yarbuh; Cesare Colasante; Marcos Eduardo Valdés Alarcón; Antonio Moreno Hernández
Abstract: Natural infection produced by the entry of promastigotes into the skin cells induces cutaneous leishmaniasis disease and the Interaction between phagocytic cells and different strains of Leishmania determine the course of disease in the mammalian host. In this study the cutaneous lesions from hamsters infected with the L. garnhami were pressed on a microscope slide, allowed to dry and methanol-fixed in order to be ultrastructurally analyzed using atomic force microscopy (AFM). Free amastigotes showed their nucleus, kinetoplast and a depression of 5 microns, corresponding to the refractil organelle characteristic of this Leishmania. Parasites inside macrophages and lymphocytes and the topographical relationship with the host cytoplasm was also observed. Parasite-host-cell interaction revealed different membrane contact. The amastigote-macrophage contact is established by small macrophage filopodio associated with its cytoplasmic reduction near the contact site of 800 nm. The amastigote-lymphocyte contact shows fusion-like behavior between the two membranes without any cell specialization. The cutaneous lesion studied with AFM allowed observation with high resolution the close contact established between the parasite and its host cells as well as details of the fine structure of the amastigotes, applying a simple and rapid tissue preparation. Resumen: La infección natural producida por la entrada de promastigotes en la piel produce leishmaniasis cutánea y la interacción entre las células fagocíticas y las diferentes cepas de Leishmania determina el curso de la enfermedad en el hospedador vertebrado. En este estudio las lesiones cutáneas de hamsteres infectados con L. garnhami fueron frotadas sobre un portaobjeto, secadas a temperatura ambiente y fijadas con metanol para analizarlas ultraestructuralmente usando un microscopio de fuerza atómica (AFM). Los amastigotes mostraron el núcleo, kinetoplasto y una depresión de 5µ, correspondiente a la organela refráctil característica de esta especie. Los parásitos dentro de los macrófagos y de linfocitos y las relaciones topográficas con el citoplasma de la célula hospedadora, revelaron diferentes tipos de contacto entre las membranas celulares. El contacto amastigote-macrófago se establece por un pequeño filopodio del macrófago asociado con reducción citoplasmática cerca del sitio de contacto de 800 nm. El conctato amastigote-linfocito mostró estrecha fusión entre las dos membranas sin ninguna especialización celular. Concluimos que las lesiones cutánes estudiadas con AFM permite la observación con alta resolución, del estrecho contacto que se establece entre los parasites y sus células hospedadoras así como, los detalles de la ultraestructura de los amastigotes aplicando una simple y rápida preparación de las muestras de tejido.
Deteccion de titulos de anticuerpos , proteinas totales , albumina y globulinas en casos de leishmaniosis cutanea tratados con glucantime
(1996) N Anez; M Valera; E Moreno; Ana Lugo de Yarbuh
Gastrocnemius skeletal muscle microvasculature and neuromuscular junction alterations in mice with experimental acute chagas infection
(2006) Ana Lugo de Yarbuh; Cesare Colasante; Maritza Alarcón; Elio Moreno
A light and transmission electron microscopy study was performed in skeletal muscles (SM) Gastrocnemius (G) from mice experimentally infected with Trypanosoma cruzi to determine changes on microvessels (MV) and neuromuscular junction (NMJ) of G. In this study 10 male (mus musculus) (20 g) were infected subcutaneally with 1.104 bloodstream trypomastigotes M/DID/Ve/02/DSM strain. Five mice were kept as uninfected controls. The parasites induced a complete paralysis of the rear limbs and death while still in the acute ChagasÂ´disease. The histopathology of SM showed inflammatory cell infiltration by mononuclear and polymorphonuclear leukocytes associated with marked parasitism in the muscle fibers of G. Indirect immunofluorescence revealed interstitial IgG deposit as bands regularly spaced along the nerve terminals at 40 days postinfection (pi). At this time T. cruzi antigens and intracellular amastigotes nests were also observed. The marked inflammatory response and morphological changes in the SM were confirmed by transmission electron microscopy. Capillary ultrastructure was seen to be altered, with points of cell cytoplasm discontinuity that appear to represent holes in the microvessel walls. This finding coincided with amastigote nests in myofibers, close contacts between trypomastigotes and endothelial cells and marked thickening of the basement membrane of the muscle vessels. Loss of capillary lumen and a process of ischemia also were observed in the SM of infected mice. The neuromuscular junction showed degeneration of intramuscular nerve fibers, reduction in the axon caliber, swollen mitochondrial, increase in the actin filaments and microtubules in the axoplasm, and swelling of the Schwann cells. Increase in the nerve terminal perimeter and most of the synaptic vesicles were localized near the presynaptic active zones and scarces in the axoplasm. At this stage of infection the changes findings in MV and NMJ of G infected with T. cruzi, as well as ischemia and alterations in the presynaptic membrane densities in the active zones, shows that the abnormal mice NMJ is associated with an activity dependent modulation of the neurotransmission, producing abnormal motor activity and paralysis of the rear limbs mice while still in the acute ChagasÂ´disease. Â
Reactivación de la infección chagásica en ratas Wistar gestantes
(2005) Elio Moreno B; M. Palma Mendez; Maritza Alarcón M; Sonia Araujo A; Ana Lugo de Yarbuh
En este trabajo investigamos en ratas Wistar crónicamente infectadas con Trypanosoma cruzi, la reactivación de la infección durante la gestación y después del parto, mediante un estudio parasitológico, inmunológico, histopatológico e inmunohistoquímico. Los resultados mostraron un control de las parasitemias patentes y/o subpatentes; títulos elevados de anticuerpos específicos anti-T. cruzi, detectándose en las ratas gestantes una disminución en los niveles de IgG y un incremento significativo de la IgM (P
The Effects of Ingesting a High-fat Diet on Wistar Rats Chronically Infected with Trypanosoma cruzi
(2009) José Leonardo Paredes; Antonio Moreno Hernández; Gloria Premoli; Maritza Alarcón; Ana Lugo de Yarbuh; J Moreno Villarreal; Sónia Araújo; Rafael J. Borges
The effects of ingesting a high fat diet on albino rats (R. norvegicus) chronically infected with Trypanosome cruzi “Planalto” were researched using serological and parasitological diagnostic tests, body mass index (BMI) quantification, detection of C-Protein Reactive (CPR), evaluation of the plasmatic lipid levels (total cholesterol, high density lipoproteins HDL and triglycerides) and the presence of lipidic deposits in the aorta artery. During the course of the chagasic infection, patent parasitemias were detected between the ages of 10 and 35 days post-infection (pi) with a maximum average of 36.68 ± 2 tryps/mm³ of blood at 25 days. At 90 days pi, the absence of parasitemias and the presence of IgG anti T. cruzi antibodies were in evidence. The chagasic rats in chronic phase (A) and the healthy controls (C) submitted to a high fat diet showed: 1. Significant variations (p0.05) in the BMI, in comparison with the rat groups receiving a normal diet (B: infected and D: healthy rats); 2. A discrete CRP reaction in the serum of infected rats B; 3. A significant increase was shown in the total cholesterol levels, HDL cholesterol and triglycerides for groups A and C in comparison with control groups B and D (p0.05). The histological study of rat arteries in group A revealed important lipid deposits located in the muscular layer near the intimal and adventitial layer. These results suggest that the increase in plasmatic lipid levels stimulated by the infectious process are the main mechanisms through which T. cruzi could be influencing the initiation or the progression of atheromatous plaque.
The Resistance of Chagasic Wistar Rat Offspring to Reinfections by Trypanosoma cruzi
(2012) Nora Mogollón; Antonio Moreno Hernández; Maritza Alarcón; Ana Lugo de Yarbuh; Martha Gloribet Ceballos Ramírez; Rafael Borges
The resistance to reinfection by Trypanosome cruzi in chagasic rat offspring was evaluated. Thirty male offspring () from infected mothers and 30 offspring from healthy mothers were used, divided into groups of 10 offspring each (I, II, III) and (IV, V, VI). The groups (I, IV) and (II, V) were inoculated and reinoculated by intradermal route with 5 × 104 metacyclic trypomastigotes of homologous (pL) and heterologous (Y) strains of T. cruzi, from laboratory infected Rhodnius prolixus, at one-month intervals. The control groups (III, VI) received saline injections. The parasitological and serological testing performed on both groups of infected offspring at 10, 20 and 30 days post-reinoculation (pr) showed significantly higher parasitemia levels in offspring from healthy mothers during the acute phase of the primary infection, the absence of bloodstream trypomastigotes after the 1st and 2nd reinoculation, and a significant increase in anti-T. cruzi antibody levels after initial inoculation and reinoculations. The histopathological and immunohistochemical analysis of heart and skeletal muscle sections from the offspring sacrificed at 45, 75 and 105 days pi, revealed the gradual establishment of myocarditis and acute myositis of variable intensity accompanied by few nests of amastigotes, a worsening of the pathologic picture produced by the initial inoculation, and the presence of abundant antigenic deposits that intensified with the reinoculations. In conclusion, the resistance of offspring born from chm to homologous and heterologous reinfection by T. cruzi strains, is produced, first, by vertical transmission of the parasites and/or humoral antibodies from infected mothers to their progeny, and second, by a sensibilization process in the host from continuous antigenic downloads produced when the inoculated parasites are destroyed.