Comparación del ordenamiento de predicciones BLUP y la respuesta a la selección en conejos cuando el efecto año-estación se considera fijo o aleatorio / Comparison of the BLUP prediction order and the response to selection in rabbits when the effect yearseason is considered to be either fixed or random

En lineas de conejos reproductivamente cerradas, criadas con generaciones discretas, existe una fuerte asociacion entre el año-estacion (AE) y los niveles de consanguinidad (F). Estudios realizados anteriormente mostraron que, cuando AE y F son considerados como efectos fijos en un modelo, la heredabilidad y la tendencia genetica se sobreestiman. El objetivo del trabajo fue investigar las consecuencias de considerar AE como fijo (M1) o aleatorio (M2) sobre la seleccion de animales. Se utilizaron 15671 registros correspondientes al numero de destetados de la linea A, del Departamento de Ciencia Animal de la Universidad Politecnica de Valencia, España. Los modelos fueron comparados en base a: los ordenamientos de los valores geneticos aditivos estimados en cada generacion y la respuesta esperada a la seleccion. Se plantearon seis escenarios segun intensidades de seleccion. En cada uno se estimo la correlacion de Spearman y se calculo el porcentaje de discordancia (D) entre los animales elegidos por M2 y no por M1. La respuesta a la seleccion para los animales escogidos por M1 o M2, fue estimada como la pendiente de la recta de regresion entre las medias de los valores geneticos predichos por M2 a traves de las generaciones. A medida que disminuyo la presion de seleccion, aumentaron las correlaciones de Spearman, disminuyendo los D. Aunque, a nivel generacion ambos estimadores no mantuvieron siempre la misma relacion. Las respuestas a la seleccion estimadas fueron similares para los animales seleccionados por M1 o M2, con lo cual no se esperan diferencias entre ambos modelos respecto a la seleccion.

In close reproductive lines of rabbits reared in discrete generations, there is a strong association between the year-season (AE) and the levels of consanguinity (F). Previous studies have shown that when AE and F were considered as fixed effects in a model, the heritability and the genetic tendency were overestimated. The objective of this work was to investigate the consequences of considering AE as either a fixed (M1) or random (M2) effect on the selection of animals. A total of 15,671 records corresponding to the number of rabbits weaned in line A, from the Department of Animal Science of the Polytechnic University of Valencia, Spain, were used. The comparison of models was based on the rankings of the estimated additive genetic values in each generation and the expected response to the selection. Six scenarios were proposed, varying in selection intensities. In each one, the Spearman correlation was estimated and the percentage of discordance (D) between the animals chosen for M2 but not for M1 was calculated. The response to selection for the animals chosen by either M1 or M2, was estimated as the slope of the regression line between the means of the genetic values predicted by M2 through generations. As the selection pressure decreased, the Spearman correlations increased, decreasing the D. However, at the generation level, both estimators did not always maintain that relationship. The estimated responses to selection were similar when the selection was based on estimated breeding values obtained by using either M1 or M2. Therefore, no differences are expected between both models with respect to selection.

Caracterización genética de cuatro poblaciones de ovinos criollos de Argentina / Genetic characterization of four populations of Argentinian creole sheep

Los ovinos criollos son los fundadores de la ganadería ovina en la Argentina y han contribuido de manera sostenida al desarrollo económico, social y cultural de algunas regiones del país. A pesar de ello, es un recurso zoogenético escasamente valorizado y por ende poco estudiado. En orden de caracterizar genéticamente a los ovinos criollos argentinos, se tomaron muestras de ADN de cuatro poblaciones representativas localizadas en las provincias de Buenos Aires, Corrientes, Santiago del Estero y Salta. Estas majadas se seleccionaron por ser grupos conservados, que presentan las características fenotípicas de la raza y no registran la introducción de animales de otras razas en el sistema de reproducción. Un total de 30 marcadores microsatélites y la región D-loop del ADN mitocondrial fueron analizados. El análisis de los microsatélites permitió evidenciar una alta diversidad genética intrapoblacional (Ho= 0,676; He= 0,685; PIC= 0,713). Dicha variabilidad es explicada por diferencias entre los patrones moleculares de los individuos estudiados que pueden clasificarse en 3 grupos de poblaciones significativamente diferentes: BA, SA, SE+CO. Dado que dichas poblaciones explican muy poco de la variabilidad total (7,6%), ellas deberían considerarse perteneciente a una misma raza. El análisis del D-loop mitocondrial demostró que los individuos analizados están relacionados con el haplogrupo asiático, el cual está ampliamente distribuido en las razas españolas que son las antecesoras de la raza criolla argentina. Los resultados obtenidos en este trabajo proveerán información para establecer criterios de manejo de este recurso genético de Argentina con el fin de implementar planes de conservación, recuperación y/o mejora de los programas.

Creole sheep are the founders of sheep farming in Argentina and have contributed in a sustained way to the economic, social and cultural development of some regions of this country. However, it is a scarcely valorised and poorly studied genetic resource. In order to genetically characterize the Argentinian Creole sheep, DNA samples were taken from four representative populations located in the provinces of Buenos Aires, Corrientes, Santiago del Estero and Salta. These flocks were selected because they are considered to be conserved groups, they have the phenotypic characteristics of the creole breed and there are no records about the introduction of animals of other breeds into those systems. A total of 30 microsatellites and the D-loop region of mitochondrial DNA were analysed. Microsatellite analysis showed high level of genetic diversity within populations (Ho= 0.676; He= 0.685; PIC= 0.713). This variability is explained by differences between molecular patterns of the studied individuals, which can be classified into three significantly different population groups: BA, SA, SE+CO. Since these populations explain very little of the total variability (7.6%), it can be considered that they belong to a same race. The analysis of the mitochondrial D-loop showed that Argentinian Creole sheep have haplotypes belonging to the Asian haplogroup, which is widely distributed in the Spanish breeds, which are considered to be their ancestors. The results obtained in the present study will provide information to develop management criteria for this genetic resource in Argentina, in order to implement their conservation, recovery and/or to develop breeding programs.

Inflammation, complement, ischemia and amoebic survival in acute experimental amoebic liver abscesses in hamsters.

We have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (AEALAH). In hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. Focal liver ischemia, always present in control AEALAH with inflammation and tissue destruction, was reproduced in radiated hamsters by injection of amoebae mixed with Superdex microspheres, but again in the absence of inflammation, amoebae caused no liver damage and disappeared in 24 h. In hamsters made hypocomplementemic by injection of purified cobra venom factor (CVF), amoebae caused AEALA indistinguishable from controls, but in leukopenic + hypocomplementemic hamsters, amoebae were unable to produce lesions and disappeared from the liver in 48 h. We conclude that inflammation and tissue damage are required for the survival of amoebae in AEALAH and for the progression of the experimental disease.

Patagonian Argentine Creole cattle polymorphism: comparison with North-West populations of this breed.

The relict Patagonian Argentine Creole cattle population consist of a small feral population (Los Glaciares population) that is geographically isolated in the South-West of Patagonia. In order to determine the level of genetic variability of this population, the polymorphism of eight structural genes and two microsatellites loci were studied using the polymerase chain reaction (PCR). In addition, genetic characterisation was used to compare Los Glaciares population and the ACc breed of cattle. Results obtained in this study show that the value of average heterozygosity of the studied loci for the Los Glaciares were not significantly different from the ACc. Furthermore, the data of this report were consistent with the hypothesis that Los Glaciares originated from ACc brought to the area by colonialists in the last century. Such data may be useful in formulating management plans for Feral Patagonian Creole cattle populations.

[Effect of tobacco combustion on the immunochemical properties of albumin]. / Efecto de la combustión del tabaco en las propiedades inmunoquímicas de la albúmina.

During tobacco burning smoker to run up substances to contain smoke as far as pulmonary tissue that is damage. In cigarette 600 degrees C are in ignition extreme, but in the other side, in contact with edge of the mouth smoker, the temperature is lower. Smoke could be delivery tobacco products until respiratory tract when temperature gradients occur in cigarette burn. For demonstration of the immunoreactive substances in tobacco smoke condense (TSC) we used a model with two cigarette arrangements: several concentrations of bovine seric albumin (BSA) applied to experimental group of cigarettes and phosphate-saline solution (PBS), 0.15 M pH 7.5 without protein to control cigarettes. Both series, experimental and control, remained at 20 degrees C during 48 h, soon afterward TSC was obtained. Higher protein concentration was observe in the experimental TSC of cigarettes expose to more elevated quantities of BSA, this was identify with polyclonal antibodies toward BSA employing counter-immunoelectrophoresis, immunoelectrophoresis, radial immunodiffusion and hemagglutination inhibition test. In summary: TSC of treat cigarettes had a little quantity of protein (BSA), but immunochemical properties of BSA in TSC were preserve because polyclonal antibodies against BSA bind to this protein. In habitual smoker some compounds present in cigarette smoke could be induce an immune response due to immunogen in tobacco substances.

[Cytotoxicity caused by tobacco]. / Citotoxicidad inducida por el tabaco.

Condensed smoke (CS) at as concentration of 0.40 mg/ml as well as urethane at 5.0 mg/ml reduced cell adherence and proliferation at percentages lower than 30 and 15% respectively. Control cells displayed 100% adherence and proliferation. Tobacco extract (TE) at 16 mg/ml inhibited cell proliferation in 65%, at 0.75 mg/ml or lower doses results were similar to control cultures and 0.1 mg/ml cell proliferation increases by 15 to 40% above controls. Urethane at 0.10 mg/ml to 0.30 mg/ml to 0.30 mg/ml favored cell proliferation by 55% above control. CS at 0.05 to 0.10 mg/ml presented similar adherence and proliferation results as control cells. MDCK cells treated with ethylenemethanesulphonate and subsequently expanded under normal conditions were incubated with CS, TE and urethane at different concentrations. Their behavior was similar to control MDCK cells. Cell cultures incubated for 3 days after their exposure to CS (0.05 mg/ml) or urethane (2.5 mg/ml) showed 50% inhibition of proliferation when compared to controls. Data obtained in this study indicate that high doses of PDCT are cytotoxic which is reflected in the inhibition of cell adherence and proliferation while low doses of PDTC stimulate these cellular phenomena.

[Smoking. Changes produced by urethane on macrophage receptors and the complement system]. / Tabaquismo. Alteraciones producidas por el uretano en los receptores de macrófagos y el sistema del complemento.

The present of communication result of the analysis action urethane, that is yield of burning tobacco, provoked alterations on macrophages, complement system and red blood cells. Our data show that urethane high concentration kill macrophages and red blood cells and severely inhibits complement activity. These findings suggest that urethane high concentrations injury to macrophage's receptors, complement system and red blood cells and these are associated with pathologic process related with passively and actively smoking individuals.

[Immunoglobulin A and tobacco antigens in patients with pneumopathy]. / Inmunoglobulina A y antígenos del tabaco en pacientes neumópatas.

Smoking is an addiction related with several cardiopulmonary diseases. Some compounds derived from tobacco combustion can be induce a response of secretory immune system, because antigen penetration is by respiratory tract epithelium, with IgA antibodies synthesis and immune complex (IC) generation. Seric anti-tobacco antibodies were showed in 44% of healthy smokers and 71% of non-smoker. In 56% of smokers and 38% at non smokers were found IC with 0.19 and 0.15 mg/ml of IgA respectively. Molecular weight of IC constituents were between 12 and 80 Kd. Sera were without free tobacco antigen. Pneumopathic patients had anti-tobacco antibodies in 100% of them and positive IC in 72% of smokers and 65% of non-smokers. IgA concentration in CI was 1.41 and 1.26 mg/ml respectively. Molecular weight of IC compounds were from 14 to 90 Kd. Free tobacco antigen in serum was observed in 44% of smokers and 41% of non-smokers pneumopathic patients. We concluded that patients with lung disease had higher frequency of anti-tobacco antibodies and IC, further IgA concentration in IC was higher and free tobacco antigen present in pneumopathic sera comparing with healthy people. The presence of circulating IC with IgA antibodies and the potential inductive influence of tobacco products in these entities, should provide an energetic stimulus to search the role of tobacco antigens in pulmonary inflammatory diseases.

[Characterization of the desmoglein in renal cells in culture]. / Caracterización de la desmogleína de células renales en cultivo.

Desmosome junctions are found in epithelial tissues. They both link cells externally and anchor cytoplasmic intermediate filaments to the plasma membrane. Quantitative and qualitative abnormalities in intercellular junctions have been described in a broad spectrum of human and animal cancers. Current efforts are aimed at exploring the possibility that some of these defects may account for the hallmarks of malignancy, namely tumour invasion and metastasis. Desmosomes are constituted by several proteins, one of them is desmoglein-1 (DG-1), a transmembrane glycoprotein who glycosylated portion is major component of the adhesion mediating desmoglia. In order to know the similarity between tissue DG-1 and cultured renal cells DG-1 was used antisera raised against DG-1 to identify cross-reacting components. Anti DG-1 antibodies stained cell-cell boundaries in a punctate fashion in epithelial tissue and on densely grown monolayers of renal cells. Radioimmunoprecipitation and immunoelectrotransference show positive reaction with anti DG-1 antibodies with desmosomes obtained from epithelial tissue and renal cells monolayers, but last one was less positive. Results suggest some minor differences between DG-1 extracted from diverse sources but they have a commun immunodominant epitope.

Evidence that G-CSF is a fibroblast growth factor that induces granulocytes to increase phagocytosis and to present a mature morphology, and that macrophages secrete 45-kd molecules with these activities as well as with G-CSF-like activity.

Evidence is provided that conditioned medium from a macrophage-like cell line contains molecules of approximately 45 kd molecular weight with granulocyte colony-stimulating factor (G-CSF)-like activity as well as with the property of inducing granulocytes to phagocytose latex particles and to mature morphologically. This type of differentiation was found to be induced on either bone marrow or induced granulocytes, but not on resident or induced macrophages. On the other hand, resident but not induced macrophages are shown to induce these types of activities when challenged by bacterial lipopolysaccharides. Evidence that macrophages produce a factor that is mitogenic for fibroblasts is also provided. This activity was measured by the induction of increased proliferation by either low-density or saturated cultures of fibroblasts. Human recombinant G-CSF was employed and found also to possess these dual capabilities of inducing both the proliferation and differentiation of granulocytes as well as the proliferation of fibroblasts. Finally, a mechanism for the regulation of myeloid cell production and differentiation is described in which G-CSF produced by macrophages not only induces granulocytes to differentiate but induces fibroblasts to proliferate and secrete macrophage colony-stimulating factor (M-CSF), which in turn makes myeloid monocyte precursors proliferate and secrete more G-CSF.

[The mechanism of natural resistance in the rat to Entamoeba histolytica]. / Estudios sobre el mecanismo de la resistencia natural de la rata a Entamoeba histolytica.

The data presented in this paper may be summarized as follows: 1) intraportal injection of a virulent strain (HM-1) of Entamoeba histolytica in Wistar rats, of both sexes, gives way to non-progressive microscopic changes, characterized by a rapid leukocytic reaction surrounding the amebas, disappearance of the parasites within 5 hours, and total lack of hepatic damage; 2) leucopenia only modifies the previous description by the fact that there are no leucocytes around the amebas, although these disappear in the same time, showing, at this moment, an early and prominent vacuolar degeneration; 3) hypocomplementaemia shows the same results as leucopenia; 4) fragments and extracts from various tissues from the rat and hamster show variable degrees of interference with the viability of axenic amebas of Entamoeba histolytica conserved in culture; only a minimal part of the interference to be due to the activity of the complement which is present in the tissue extracts.

Niveles de IgA serica en padecimientos reumaticos asociados a fenomenos autoinmunes. / Level of seric IgA in rheumatic diseases associated with autoimmune phenomenon

En las enfermedades autoinmunes se ha propuesto la existencia de una disfuncion en la regulacion de la respuesta inmune con alteracion en la concentracion de IgA. En este trabajo se analizo el nivel de la IgA serica en individuos con enfermedades reumaticas asociadas a fenomenos autoinmunes y en sujetos con padecimientos cardiovasculares. Ademas se cuantificaron las gammaglobulinas (IgG y las euglobulinas (IgM). En los pacientes con fiebre reumatica, artritis reumatoide y gota, se observo elevacion de IgA serica. Tambien se encontro hipergammaglobulinemia policlonal en varios grupos de reumaticos. Las euglobulinas tuvieron un valor promedio alto en los individuos con artritis reumatoide. Se concluye que en algunos padecimientos reumaticos con fenomenos autoinmunes existe una disfuncion en la respuesta inmune manifestada por hipergrammaglobulinemia policlonal y por incremento de IgA serica

Anticuerpos contra productos extracelulares del estreptococo. (Estudio inmunoelectroforetico en pacientes cardiopatas). / Antibodies against streptococcal extracellular products.(Immunoeletrophoretic study in cardiac patients

Debido a que los productos extracelulares del estreptococo se han implicado en el dano cardiaco que ocurre en la fiebre reumatica se estudio el suero de 126 pacientes cardiopatas y el de 10 personas sanas, para determinar por inmunoeletroforesis la presencia de anticuerpos contra dichos productos estreptococcicos. Los anticuerpos contra estreptoquinasa-estreptodornasa se encontraron en el 61 a 68% de los pacientes cardiopatas y en el 75% de los sujetos sanos; los anticuerpos contra el sobrenadante de cultivo de estreptococos, solo se observaron en el 6 a 7% de los pacientes y en ninguno de los sujetos sanos. Las bandas de precipitacion en inmunoeletroforesis fueron analizadas de acuerdo a sus patrones electroforeticos y de difusion. Cuando se emplearon estreptoquinasa-estreptodornasa como antigenos se reconocio mas frecuentemente a la banda A por los sueros de pacientes con fiebre reumatica activa; otras bandas se encontraron con menor frecuencia. Los sueros de individuos sanos fueron positivos contra la banda E; pero no reconocieron ni la banda B, ni la H

[Effect of streptolysin O on the Purkinje fibers of the heart in dogs]. / Efectos de la estreptolisina "O" sobre las fibras de Purkinje del corazón de perro.

Streptolysin "O", an exotoxin of the beta-hemolytic streptococcus, has been shown to have very marked cardiotoxic effects. The data found in the literature suggest that ventricular conducting tissues are severely damaged by this toxin. The purpose of this paper is to study the effects that several concentration of the toxin have on the transmembrane potentials, input resistance and ultrastructure of canine isolate Purkinje fibers. When the preparations were exposed to the toxin, they showed important changes in most of the parameters of the transmembrane potentials. The most important were: a depolarization, a reduction of the amplitude of the action potentials and their upstroke velocities, and a marked shortening of their duration. Input resistance was also markedly decreased. These actions were progressive, until unexcitability was reached. All of the changes observed were irreversible. The ultrastructure of the cells also showed important alterations, mainly at the sarcolemma and mitochondriae. From the results described in this paper, both in terms of the electrophysiological and the morphological effects of streptolysin "O", we can conclude that the cardiotoxic effects of the toxin are due to an effect on the ventricular conducting tissues.

[Ontogeny of cardiac antigens in chickens]. / Ontogenia de los antígenos del corazón de pollo.

The embryonic development of the heart is a complex process in which molecular events take place during the cellular recognition, growth regulation and morphogenesis. In this work, the stage in which cardiac antigens are produced in the chick embryo was established by the use of sera directed against cockerel's heart antigens. Chick embryos were studied in different stages of development, classified according to the Hamburger and Hamilton system. Soluble and insoluble fraction of the cockerel's heart were obtained and used to immunize rabbits; the presence of anti-heart antibodies was tested by double microimmunodiffusion. Antisera to yolk and albumin envelopment, serum and cockerel erythocytes were also produced in order to recognize other molecules in the embryos. Anticockerel red cells antibodies were determined by direct hemaglutination. It was shown that heart antigens appear since the second stage of embryonic development and remain during the whole development, although in some stages it seems that the concentration of some antigens decreases. It is possible that the molecular changes in the heart tissue are manifested as variations in concentration of the cardiac substances.

Immunological and ultrastructural study of the surface of isolated rat testis germinal cells.

In the present study, cross absorption tests and indirect immunofluorescence detected antigenic differences between isolated testicular cell populations from 21 and 38 day old rats, respectively. Qualitatively, spermatids were the only cell type difference between these populations. Spermatozoa from adult rats were also studied. Our findings suggest that spermatocytes, spermatids and spermatozoa shared on or more antigens; spermatids and spermatozoa seemed to share one or more antigens not observed in spermatocytes by indirect immunofluorescence. Various patterns of immunofluorescence were encountered, suggesting differences in amount and distribution of antigens among the cells studied. The supramolecular appearance of the surface of spermatocyte enriched populations and of spermatid enriched populations were compared by scanning electron microscopy (SEM) and no striking difference was observed between both cell populations.

Estudio inmunologico y ultraestructural de la superficie de celulas testiculares aisladas de rata. / Immunological and ultrastructural study of the surface of isolated rat testis germinal cells

En este estudio se informan diferencias antigenicas, evaluadas por absorcion cruzada e inmunofluorescencia indirecta, entre dos poblaciones de celulas testiculares aisladas de ratas inmaduras: una enriquecida en espermatocitos (71 por ciento). Nuestros hallazgos sugieren que los espermatozoides comparten uno o mas antigenos. Ademas, las espermatides y los espermatozoides tienen uno o mas antigenos que no se observaron por inmunofluorescencia en los espermatocitos. Se encontraron diferencias en la inmunofluorescencia que sugieren modificaciones en la cantidad y distribucion de los antigenos entre las celulas estudiadas. Por medio del microscopio electronico de barrido se estudio la apariencia supramolecular de la superficie de espermatides y de espermatocitos. No mostraron diferencias significativas entre si