Parásitos gastrointestinales como indicadores en vizcacha

Los parásitos son importantes indicadores de distintos aspectos bioecológicos de sus poblaciones hospedadores. Los helmintos son uno de los marcadores biológicos más reconocidos. Se caracterizaron las comunidades de helmintos gastrointestinales en poblaciones continentales e insulares de vizcacha. El objetivo de este trabajo es analizar las comunidades de parásitos gastrointestinales asociadas a poblaciones continentales e insulares de vizcacha en el sudoeste bonaerense y utilizar esta información como indicador del estado de las poblaciones y de su de su posible conexión a través de la migración de individuos.Área: Ciencias Biológicas, Ambiente y Salu

Relación entre la carga parasitaria total y algunos parámetros hematológicos de <i>Rhamdia sapo</i> val. (Pisces) en condiciones naturales

The purpose of the present research is to evaluate the degree of the statistical association between the total burden of parasites in the South American Catfish, Rhamdia sapo, and hematological variables studied under natural conditions. The following 12 parasite species were identified: 2 ciliate protozoans, 1 flagellate, 1 monogenean, 3 digeneans, 1 cestode, 2 nematodes, and 2 crustaceans. Of the parasite species collected from the tegument, branchias, body cavity, and digestive tube, some of them (namely, Argulus violaceus, Urocleidoides mastigatus, Hysterothylacium rhamdiae, Acanthostomun gnerii, Proteocephalus jamdiae, Trichodina sp. and Cucullanus sp.) have been previously cited. However, Ichthyophthirius multifiliis, Spironucleus sp., Lernaea cyprinacea, and Thometrema sp. are cited for the first time in Argentina as a parasite of this fish. The non-parametrical Spearman’s rank correlation test indicated that the total burden of parasites in the South American Catfish, Rhamdia sapo, exerts no significant action under the hematological variables studied in this research, namely, red blood cell count, white blood cell count, thrombocyte count, hemoglobin concentration, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Relación entre la carga parasitaria total y algunos parámetros hematológicos de <i>Rhamdia sapo</i> val. (Pisces) en condiciones naturales

The purpose of the present research is to evaluate the degree of the statistical association between the total burden of parasites in the South American Catfish, Rhamdia sapo, and hematological variables studied under natural conditions. The following 12 parasite species were identified: 2 ciliate protozoans, 1 flagellate, 1 monogenean, 3 digeneans, 1 cestode, 2 nematodes, and 2 crustaceans. Of the parasite species collected from the tegument, branchias, body cavity, and digestive tube, some of them (namely, Argulus violaceus, Urocleidoides mastigatus, Hysterothylacium rhamdiae, Acanthostomun gnerii, Proteocephalus jamdiae, Trichodina sp. and Cucullanus sp.) have been previously cited. However, Ichthyophthirius multifiliis, Spironucleus sp., Lernaea cyprinacea, and Thometrema sp. are cited for the first time in Argentina as a parasite of this fish. The non-parametrical Spearman’s rank correlation test indicated that the total burden of parasites in the South American Catfish, Rhamdia sapo, exerts no significant action under the hematological variables studied in this research, namely, red blood cell count, white blood cell count, thrombocyte count, hemoglobin concentration, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

The RhoA transcriptional program in pre-T cells

The GTPase RhoA is essential for the development of pre-T cells in the thymus. To investigate the mechanisms used by RhoA to control thymocyte development we have used Affymetrix gene profiling to identify RhoA regulated genes in T cell progenitors. The data show that RhoA plays a specific and essential role in pre-T cells because it is required for the expression of transcription factors of the Egr-1 and AP-1 families that have critical functions in thymocyte development. Loss of RhoA function in T cell progenitors causes a developmental block that pheno-copies the consequence of losing pre-TCR expression in Recombinase gene 2 (Rag2) null mice. Transcriptional profiling reveals both common and unique gene targets for RhoA and the pre-TCR indicating that RhoA participates in the pre-TCR induced transcriptional program but also mediates pre-TCR independent gene transcription

The Molecular Signature Underlying the Thymic Migration and Maturation of TCRαβ+CD4+CD8- Thymocytes

BACKGROUND: After positive selection, the newly generated single positive (SP) thymocytes migrate to the thymic medulla, where they undergo negative selection to eliminate autoreactive T cells and functional maturation to acquire immune competence and egress capability. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate the genetic program underlying this process, we analyzed changes in gene expression in four subsets of mouse TCRαβ(+)CD4(+)CD8(-) thymocytes (SP1 to SP4) representative of sequential stages in a previously defined differentiation program. A genetic signature of the migration of thymocytes was thus revealed. CCR7 and PlexinD1 are believed to be important for the medullary positioning of SP thymocytes. Intriguingly, their expression remains at low levels in the newly generated thymocytes, suggesting that the cortex-medulla migration may not occur until the SP2 stage. SP2 and SP3 cells gradually up-regulate transcripts involved in T cell functions and the Foxo1-KLF2-S1P(1) axis, but a number of immune function-associated genes are not highly expressed until cells reach the SP4 stage. Consistent with their critical role in thymic emigration, the expression of S1P(1) and CD62L are much enhanced in SP4 cells. CONCLUSIONS: These results support at the molecular level that single positive thymocytes undergo a differentiation program and further demonstrate that SP4 is the stage at which thymocytes acquire the immunocompetence and the capability of emigration from the thymus

The naïve airway hyperresponsiveness of the A/J mouse is Kit-mediated

There is a wide variation among humans and mice in airway hyperresponsiveness (AHR) in the absence of allergen sensitization, i.e., naïve AHR. Because mast cell (MC) activation is thought to mediate AHR in atopic asthmatic subjects, we asked whether MCs mediate naïve AHR in A/J mice. We generated an A/J congenic strain lacking c-Kit by introgression of the Wv mutation, which resulted in the elimination of MCs and the abrogation of naïve AHR. Imatinib, which disrupts Kit signaling, also abrogated AHR in A/J mice. Remarkably, introduction of the Vga9 Mitf mutation into the A/J background resulted in the ablation of MCs but did not ameliorate AHR. These results indicate that c-Kit is required for development of AHR in an MC-independent fashion