Comparación del nivel de ingreso del jefe de hogar entre aglomerados; income salary comparison of the heads of family between urban areas Leguizamón,María C.; Martinez, Carlos Ismael; Panico, Adriana F. La Encuesta Permanente de Hogares (EPH) constituye un programa de alcance nacional orientado a obtener información que permite caracterizar a la población en términos demográficos, ocupacionales, habitacionales y de ingresos, desarrollando un sistema integrado de indicadores sociales.    Originalmente el objetivo en este trabajo era realizar una comparación del nivel de ingreso de los jefes de hogar entre los aglomerados urbanos San Miguel de Tucumán-Tafí Viejo con los aglomerados urbanos de las otras provincias que constituyen el Noroeste Argentino de acuerdo a las características de los mismo y de los hogares considerados en la muestra. Sin embargo en la EPH fuente no se discriminan los aglomerados urbanos de las provincias de Salta, Jujuy, Catamarca y Santiago del Estero individualmente, sino que se identifican todas juntas con un mismo código como "resto del NOA". De acuerdo a los datos obtenidos de la fuente2, decidimos considerar sólo dos aglomerados urbanos de importancia San Miguel de Tucumán-Tafí Viejo, con menos de 500.000 habitantes y resto del NOA con más de 500.000 habitantes.   La variable a medir es el Ingreso Total del Jefe de Hogar (variable respuesta) y el objetivo es analizar si está influenciada por las variables a nivel Macro: estrategias del hogar3 (definiciones dadas en el anexo) y tamaño del aglomerado y a nivel Micro: estado de actividad, condición de actividad, nivel de educación, edad, sexo, si posee obra social y si tiene un plan jefa-jefe de hogar.4; The multilevel analysis arised in education, sociology and demographic areas, being applied to several situations, where lower level unities or "microunities" interweave with others from the higher level or "macrounities". In economic researches this analysis is known as Panel Data Analysis. Through this methodology, we can study the simultaneous effect of individual and group variables and their interactions over a dependent variable at individual level. The multilevel models are a unique case of the Generalized Linear Models and they can be applied to other analysis systems like, repeated measures analysis, analysis of categorical data, models of structural equations, time series processes and non linear regression. The objective of this paper is to apply the multilevel data analysis methodology to data from Encuesta Permanente de Hogares (EPH). To compare the income level of the heads of family between urban areas in agreement with their characteristics and those of the families from the sample. The analyzed data are from urban areas of Gran Tucumán - Tafí Viejo and from the rest of the Northwest of Argentina (NOA), taken out from the EPH continue, of the first quarter 2005. We consider urban areas and families in the MACRO level and heads of family in the MICRO level

Efficacy of atelocollagen honeycomb scaffold in bone formation using KUSA/A1 cells Rodriguez, Andrea Paola; Missana, Liliana Raquel; Nagatsuka, Hitoshi; Gunduz, Mehmet; Hidetsugu Tsujigiwa,; Rivera, Rosario; Nagai, Noriyuki To induce new bone formation, mesenchymal stem cells were seeded onto atelocollagen honeycomb scaffold. We evaluated the efficacy of this scaffold combined with KUSA/A1 cells in vivo. KUSA/A1 cells alone and with atelocollagen were implanted in the subcutaneous pockets of 4-week-old male SCID mice. The transplants were subjected to radiographical, histological, and immunohistochemical examinations after 2 and 4 weeks of implantation. Radiographically, both KUSA/A1 cells alone and KUSA/ A1-atelocollagen showed some radiopaque areas formation but the latter disclosed a larger amount. Histologically, KUSA/A1 cells alone showed few small islands of new bone formation surrounded by a thin layer of cellular proliferation. On the other hand, KUSA/A1-atelocollagen revealed abundant new bone formation as well as cellular proliferation. We also determined the immunolocalization of type I collagen, CD34, osteocalcin, osteopontin, and PCNA in this newly formed bone. Our results indicated that collagen scaffold plays an important role allowing vessel formation and cell anchorage, especially through the proliferation and differentiation process in a confined space. This study supports tissue engineering as an alternative for treating different target diseases, such as trauma or congenital defects, and enhances existing therapeutic applications

Slant total electron content for sirio-mortelliccio ray path Cabrera, Miguel Angel; Ezquer, Rodolfo Gerardo; Spalla, Paolo The Total Electron Content (TEC) is used to indicate the ionisation of the ionosphere. TEC is a quantity that concern for predicting space weather effects on telecommunications, improving the accuracy of satellite navigation, fly control vehicles and other systems that use transionospheric signals, because the ionospheric layer affects the mentioned signals. In this work the Slant Total Electron Content (STEC) was calculated with a technique that uses so-called «auxiliaries stations model», and a Chapman layer with scale height equal to atomic oxygen scale height (CHO). The validity was checked with STEC measurements obtained from geosynchronous satellite signals, for SIRIO-Mortelliccio link considering solstices and equinox, in high solar activity period. In general, the deviations between predictions and measurements were lower than 30% for 16 h per day (average). The results suggest that additional studies for other links and solar activity are required in order to improve the model predictions.

Análisis geométrico de localización del modelo elastoplástico parabólico de Drucker-Prager dependiente de gradientes Vrech, Sonia Mariel; Etse, Jose Guillermo En este trabajo se presenta el método geométrico para el análisis de las propiedades de localización del modelo elastoplástico parabólico de Drucker-Prager dependiente de gradientes. El modelo es termodinámicamente consistente. A partir de la solución de la condición de bifurcación discontinua de la elastoplasticidad dependiente de gradientes para pequeñas deformaciones, se formula la elipse de localización en las coordenadas de Mohr. La condición de tangencia entre la elipse de localización y el círculo de Mohr correspondiente al estado de tensiones define el tipo de falla (difusa o localizada) y las direcciones críticas de bifurcación discontinua. Los resultados del análisis geométrico de localización ilustran la capacidad del material elastoplástico parabólico de Drucker-Prager dependiente de gradientes, de suprimir los modos de falla localizada de la formulación clásica o local del modelo, que tiene lugar cuando el módulo de endurec./abland adoptado H iguala al crítico (máximo) de localización Hc. Sin embargo esta propiedad regularizante de la formulación del modelo parabólico de Drucker-Prager basada en gradientes se diluye no solamente en el caso extremo cuando la longitud característica l tiene a cero sino también cuando Hc.

Mating incompatibility among populations of the south american fruit fly Anastrepha fraterculus (Wied.) (Diptera: Tephritidae).; Compatibilidad para el apareamiento entre distintas poblaciones de la mosca sudamericana de la fruta, Anastrepha fraterculus (Wiedemann) Vera, María Teresa; Cáceres, Carlos; Wornayporn, Viwat; Islam, Amirul; Robinson, Alan S.; de la Vega, Marcelo Horacio; Hendrichs, J.; Cayol, J-P Mating compatibility among different populations of the South American fruit fly, Anastrepha fraterculus (Wiedemann) was assessed through mating tests in pairwise combinations. Screened cages, inside a greenhouse, containing Citrus trees were used. Mating compatibility was determined using the Index of Sexual Isolation. Most of the populations were non-compatible with each other and thus sexually isolated. Of these, Tucumán (Argentina) and Piracicaba (Brazil) populations showed a lower degree of isolation, while the other tested combinations were highly isolated. Full mating compatibility was detected only between two Argentinean (Concordia and Tucumán) and two Peruvian populations (La Molina and Piura+La Molina). Flies were sexually active at different times of the day: Tucumán, Concordia and Piracicaba populations presented an early morning peak, La Molina and Piura+La Molina were active around midday and Ibague (Colombia) late in the afternoon. Manipulation of light-phase conditions, to match the times of maximum sexual activity, did not increase the compatibility between La Molina and Tucumán. Based on these behavioral results, which confirm morphometric, genetic and other evidence, the taxonomic revision of this cryptic species complex is warranted. One practical implication is that colonies of this pest to be used in any sterile insect technique approach should be derived from the target population or from a compatible one. Regional efforts should be initiated to determine the distribution of each subgroup and their relationship with each other in terms of compatibility.; Se evaluó la compatibilidad para el apareamiento entre distintas poblaciones de la mosca Sudamericana de la fruta, Anastrepha fraterculus (Wiedemann), mediante pruebas de apareamiento confrontando dos poblaciones por vez. Se utilizaron jaulas con árboles de Citrus limon (L.) en un invernadero. La compatibilidad para el apareamiento se determinó con el ṍndice de aislamiento sexual. La mayorṍa de las poblaciones fueron no compatibles y consecuentemente estuvieron aisladas entre sṍ. Entre estas, las poblaciones de Tucumán (Argentina) y Piracicaba (Brasil) presentaron el menor grado de aislamiento, mientras que las otras presentaron alto aislamiento. Se detectó compatibilidad solamente entre dos poblaciones argentinas (Concordia y Tucumán) y dos poblaciones peruanas (La Molina y Piura ⫹ La Molina). Las poblaciones estuvieron sexualmente activas en distintos momentos del día: Tucumán, Concordia y Piracicaba presentaron un pico de actividad al amanecer, La Molina y Piura ⫹ La Molina al mediodía e Ibague (Colombia) al atardecer. La manipulación de los horarios del ciclo de luz-oscuridad, para coincidir la hora de máxima actividad sexual, no aumentó la compatibilidad entre La Molina y Tucumán. Basándonos en estos resultados comportamentales, que confirman las evidencias genéticas y morfológicas registradas, es necesaria una revisión taxonómica de este complejo de especies. Una consecuencia práctica sería que las colonias a utilizar para la cría masiva de insectos estériles para la implementación de la técnica del insecto estéril para el control de esta plaga deben originarse de la población a controlar o de una población compatible. Se deben iniciar esfuerzos regionales para determinar la distribución de cada subgrupo y su relación en términos de compatibilidad.

Identidad local. Estrategias de ampliación de “la ruta del adobe”. Catamarca, Argentina. Chaila, Josefina del Huerto; Carrizo, Maria Fernanda La búsqueda de lo propio se contrapone al actual paradigma cultural global. Lacoexistencia de tiempos y formas de vida interrelacionados en un medioconvulsionado nos lleva a valorar lo autóctono como una reliquia y recuerdo de lo quenos identifica. El proceso de globalización en el que estamos inmersos tiende a lahomogeneización, esto provoca reacciones adversas tendientes a la búsqueda de lolocal. Las herramientas que nos brinda el turismo para tomar contacto y dar a conocerlo autóctono, nos lleva a buscar estrategias que posibiliten el conocimiento y lavaloración de los pueblos, sus costumbres, su organización social, la configuración ydisposición de la arquitectura civil y doméstica. La “ruta del adobe”, es un recorridoturístico conformado por viviendas vernáculas construidas con materiales y técnicastradicionales. La propuesta de ampliación parte de los siete iconos de arquitecturareligioso-civil y se expande tomando elementos de la arquitectura doméstica queconfigura el territorio. A lo largo del recorrido se evidencia la estrecha relación de laarquitectura vernácula con el entorno. Las construcciones tradicionales a lo largo delcamino, son el testimonio de la historia local y de las costumbres populares. El trabajopresenta estrategias para mantener los rasgos que caracterizan la identidad local a lolargo del camino del adobe en la provincia de Catamarca, ampliando el recorrido ypotencializando los beneficios turísticos derivados de esta acción. Conservar,preservar y fortalecer los elementos que lo conforman y sus características, tienden ala sustentabilidad de la identidad local.

The fumigant and repellent activity of aliphatic lactones against Pediculus human us capitis (Anoplura: Pediculidae) Toloza, Ariel Ceferino; Zygadlo, Julio Alberto; Mougabure Cueto, Gastón Adolfo; Zerba, Eduardo Nicolás; Faillaci, Silvina Mabel; Picollo, Maria Ines New alternative insecticides are necessary for the chemical control of head lice. In this study the fumigant knockdown time 50% (KT50) and repellency index (RI) of three aliphatic lactones was compared with two essential oils and DDVP, against permethrin-resistance Pediculus humanus capitis from Argentina. In the fumigant assay, none of the lactones were effective compared to the highest activity of eucalyptus (KT50 15.53 m). In the repellency test, the three lactones were equally or more effective (RI ranging from 60.50 to 76.68) than the positive control (piperonal). These lactones are promising as head lice repellents.

Familia, comercio y redes sociales : Dos familias a fines del período colonial Quiñonez, Maria Mercedes En este artículo nos centramos a fines del período colonial para analizar las trayectorias de Domingo Antonio Patrón y Francisco Manuel Costas, comerciantes que desde su llegada a la ciudad de Salta, en el último tercio del siglo XVIII, se insertan en la sociedad local y conforman redes de relaciones y vínculos en distintos circuitos económicos. Este estudio de caso nos permite recuperar, desde otra escala de análisis, la estructuración del grupo de los comerciantes, que constituyen a fines de la colonia una elite periférica o secundaria, y sus múltiples relaciones con la elite local tradicional, en una sociedad en transición. Además, nos permite ver los distintos caminos del ascenso social y económico en la sociedad tardocolonial; la permanencia de valores como el linaje y la propiedad de la tierra para la elite más tradicional, como los comerciantes que arriban en el período borbónico logran insertarse en ese entramado social y el papel que la riqueza– derivada del comercio– adquiere en esta sociedad. Las dos trayectorias analizadas presentan patrones diferentes de comportamiento de los comerciantes salteños, a fines del período colonial.

Hidrogeología de Argentina; Hydrogeology of Argentina Auge, Miguel Pedro; Wetten, Cristian; Baudino, Guillermo; Bonorino, Alfredo Guillermo; Gianni, R.; González, N.; Grizinik, M.; Hernandez, Mario Alberto; Rodríguez, J.; Sisul, Ana Clara; Tineo, Alfredo; Torres, C. Se mencionan las características hidrogeológicas de la República Argentina, en su ámbito continental que ocupa 2.800.000 km2 y otro que contiene a la Antártida Argentina, Islas Malvinas, Georgias, Sandwich, Orcadas y Shetland, del Sur, en 1.000.000 de km2 adicionales. Para la caracterización se subdividió al territorio en 18 regiones hidrogeológicas, sobre la base de la incidencia que ejercen en el agua subterránea, los componentes geológico, climático, geomórfico y biótico. Además, se citan los usos actuales del agua y los previstos en el futuro, como así también los conflictos derivados de su empleo. Finalmente se sintetiza el ordenamiento institucional y legal, referidos a los recursos hídricos.; The hydrogeologic behavior of the Argentine Republic is mentioned, in their continental environment that occupies 2,800,000 km2 and another that contains the Argentine Antartic and the islands of Malvinas, Georgias, Sandwich, Orcadas and Shetland, of the South (1,000,000 additional km2). For the characterization the territory was subdivided in 18 hydrogeologic regions, on the base of the incidence that exert in the groundwater, the geologic, climatic, geomorphic, and biotic components. The current uses of the water are mentioned and it forseen in the future, how so also the conflicts derived of their employment. Finally the institutional and legal arrangement referred to the water resources is synthesized.

Pressure sensitivity of the ferromagnetic transition in perovskite manganites revisited Garbarino, Gaston Leonel; Acha, Carlos Enrique; Polla, Gabriela Maria; Leyva, Adelma Graciela It was already shown that a qualitative understanding of the pressure effects on the ferromagnetic transition temperature (Tc) of the perovskite manganites (AMnO3) results from the variation of the geometric factors that control the bandwidth, the Mn-O-Mn bond angle and the Mn-O bond length and also from the reduction of the effective mass related to the polaronic nature of the carriers. But, up to now, a quantitative agreement was not really obtained, particularly for the hole-doped manganites. Here, we present results on the pressure effects in the Tc of La 0.8(Ca,Sr)0.2MnO3 ceramic samples. Our results are described within a phenomenological approach based on the well known dependence of Tc on the mean A ionic radius, that gives a good quantitative agreement of the pressure sensitivity of Tc for several hole-doped manganites. © 2006 American Institute of Physics.

CDW and CDW-EIS calculations for FDCSs in highly charged ion impact ionization of helium Ciappina, Marcelo Fabián; Cravero, Walter Ruben In this work we present fully differential cross sections (FDCS) calculations using CDW and CDW-EIS theories for helium single ionization by 100 MeV/amu and 2 MeV/amu C6+ and 3.6 MeV/amu Au24+ and Au53+ ions. We performed our calculations for different momentum transfers and ejected electron energies. We study the influence of the internuclear potential on the ejected electron spectra. We discuss different regimes where the internuclear interaction can or cannot be neglected. We compare our calculations with experimental data available. It is shown that for high impact energy and small momentum transfer, internuclear potential effects can be neglected in FDCSs.

Classification of dispersion equations for homogeneous, dielectric-magnetic, uniaxial materials Depine, Ricardo Angel; Inchaussandague, Marina Elizabeth; Lakhtakia, Akhlesh The geometric representation at a fixed frequency of the wave vector (or dispersion) surface ω(k) for lossless, homogeneous, dielectric-magnetic uniaxial materials is explored for the case when the elements of the relative permittivity and permeability tensors of the material can have any sign. Electromagnetic plane waves propagating inside the material can exhibit dispersion surfaces in the form of ellipsoids of revolution, hyperboloids of one sheet, or hyperboloids of two sheets. Furthermore, depending on the relative orientation of the optic axis, the intersections of these surfaces with fixed planes of propagation can be circles, ellipses, hyperbolas, or straight lines. The understanding obtained is used to study the reflection and refraction of electromagnetic plane waves due to a planar interface with an isotropic medium. © 2006 Optical Society of America.

Plane-Wave Diffraction at a Periodically Corrugated Interface Between an Isotropic Medium and a Gyroelectromagnetic Uniaxial Medium Gigli, Miriam Laura; Inchaussandague, Marina Elizabeth; Depine, Ricardo Angel A formulation of the Rayleigh method for modeling unidimensional periodically corrugated gyroelectromagnetic uniaxial gratings with shallow grooves is presented. The orientation of the preferred axis of the anisotropic medium is arbitrary and incidences from both media are considered. We show that the present method gives reliable results for groove height to period ratio up to 0.3. Numerical examples for sinusoidal gratings in classical and conical mountings are provided. © 2006, The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.

Modeling broadband electromagnetic induction responses of 2-D multilayered structures Martinelli, Hilda Patricia; Osella, Ana Maria; Lascano, Eugenia Dual-coil frequency-domain electromagnetic induction (EMI) systems are commonly used as detectors of buried metallic objects, but they are also increasingly used for environmental purposes such as detection of contaminant plumes and archaeological prospection. Usually, data are analyzed directly by visualizing the in-phase and quadrature components, and also by applying one-dimensional inversion methods. Besides, there exist three-dimensional (3-D) forward and inverse modeling codes based on finite-difference techniques, but these methods are not routinely applied because their computation cost for real geophysical situations is still too high. The computation cost is significantly lower for two-dimensional (2-D) structures since this problem is not 3-D but 2.5-D. Few 2.5-D methods have been published in the last years, based on finite-element techniques, but for the case of electric dipole sources. In this paper, the authors present a 2.5-D forward-modeling algorithm, based on Rayleigh-Fourier expansions, for calculating the response of 2-D multilayered earth with irregular boundaries to the magnetic-dipole sources. Using this code, the authors numerically simulated the dual-coil frequency-domain EMI response of a soil model that could be found in environmental research. They considered a buried nonmetallic object, conductive with respect to the host media, and calculated its response for different orientations of the transmitter and receiver coils. The best resolution for detecting and characterizing this object corresponded to the configuration in which the axes of the transmitter and receiver dipoles were parallel to the ground surface and perpendicular to the symmetry axis of the buried objects, and the axis of the instrument was parallel to that symmetry axis. Finally, the authors interpreted the field data from a profile exhibiting resistive anomalies, corresponding to underground contamination, by using their forward code and a trial-and-error procedure. This profile had been previously characterized through the inversion of dipole-dipole electrical data. They considered that result to select their starting multilayered model. They obtained a good correlation between the EMI data and the synthetic response of the final multilayered model. Besides, this model is consistent with the image of the electrical inversion. During the modeling process, the method showed to be practical and versatile and to have a good convergence. © 2006 IEEE.

Endogenous or exogenous coagulation factor level and the response to activated protein C Gennari, Laura C.; Blanco, Alicia Noemi; Dominguez, Maria Paula; Grosso, Silvia H.; Lazzari, María Ángela The abnormal response to activated protein C could be the mechanism to explain the prothrombotic role of elevated coagulation factor levels. We evaluated the effect of factor VIII, II, or X (FVIII, FII, or FX) levels on activated protein C resistance technique and its association with the resistant phenotype.

The biological sense of cancer: a hypothesis Ruggiero, Raul Alejandro; Bustuoabad, Oscar David Most theories about cancer proposed during the last century share a common denominator: cancer is believed to be a biological nonsense for the organism in which it originates, since cancer cells are believed to be ones evading the rules that control normal cell proliferation and differentiation. In this essay, we have challenged this interpretation on the basis that, throughout the animal kingdom, cancer seems to arise only in injured organs and tissues that display lost or diminished regenerative ability.

Amyloid-β peptide remnants in AN-1792-immunized Alzheimer's disease patients: A biochemical analysis Patton, R. Lyle; Kalback, Walter M.; Esh, Chera L.; Kokjohn, Tyler A.; Van Vickle, Gregory D.; Luehrs, Dean C.; Kuo, Yu-Min; Lopez, John; Brune, Daniel; Ferrer, Isidro; Masliah, Eliezer; Newel, Amanda J.; Beach, Thomas G.; Castaño, Eduardo Miguel; Roher, Alex E. Experiments with amyloid-β (Aβ)-42-immunized transgenic mouse models of Alzheimer's disease have revealed amyloid plaque disruption and apparent cognitive function recovery. Neuropathological examination of patients vaccinated against purified Aβ-42 (AN-1792) has demonstrated that senile plaque disruption occurred in immunized humans as well. Here, we examined tissue histology and quantified and biochemically characterized the remnant amyloid peptides in the gray and white matter and leptomeningeal/cortical vessels of two AN-1792-vaccinated patients, one of whom developed meningoencephalitis. Compact core and diffuse amyloid deposits in both vaccinated individuals were focally absent in some regions. Although parenchymal amyloid was focally disaggregated, vascular deposits were relatively preserved or even increased. Immunoassay revealed that total soluble amyloid levels were sharply elevated in vaccinated patient gray and white matter compared with Alzheimer's disease cases. Our experiments suggest that although immunization disrupted amyloid deposits, vascular capture prevented large-scale egress of Aβ peptides. Trapped, solubilized amyloid peptides may ultimately have cascading toxic effects on cerebrovascular, gray and white matter tissues. Anti-amyloid immunization may be most effective not as therapeutic or mitigating measures but as a prophylactic measure when Aβ deposition is still minimal. This may allow Aβ mobilization under conditions in which drainage and degradation of these toxic peptides is efficient.

Differential involvement of ERK1-2 and p38MAPK activation on Swiss 3T3 cell proliferation induced by prostaglandin F2alpha Dekanty, Andres; Giulianelli, Sebastian Jesus; Coso, Omar Adrian; Rudland, Phillip S.; Jimenez de Asua, Luis Adan Felipe Prostaglandin F2alpha (PGF2alpha) induces cyclin D1 expression and DNA synthesis in Swiss 3T3 cells. In order to assess which signaling mechanisms are implicated in these processes, we have used both a pharmacological approach and interfering mutants. We demonstrate that PGF2alpha induces extracellular-signal-regulated kinase (ERK1-2) and p38MAPK activation, and inhibition of any of these signaling pathways completely blocks PGF2alpha-stimulated DNA synthesis. We also show that ERK1-2, but not p38MAPK activation is required to induce cyclin D1 expression, strongly suggesting that the concerted action of cyclin D1 gene expression and other events are required to induce complete phosphorylation of retinoblastoma protein and S-phase entry in response to PGF2alpha.

Retinal dysfunction in patients with chronic Chagas’disease is associated to anti-Trypanosoma cruzi antibodies that crossreact with rhodopsin Matsumoto, Silvia C.; Labovsky, Vivian; Roncoroni, Marcela; Guida, Maria Catalina; Gimenez, Luisa; Mitelman, Jorge; Gori, Horacio; Jurgelevicius, Renata; Grillo, Alejandro; Manfredi, Pablo; Levìn, Mariano J.; Paveto, Cristina To investigate retinal involvement in chronic Chagas' disease, we performed electroretinography and retinal fluorescein angiography studies in chagasic patients. Our results demonstrated a dissociated electrophysiological response characterized by both an abnormal reduction of the electroretinographic b-wave amplitude and a delayed latency, under the dark-adaptated condition. These alterations are compatible with a selective dysfunction of the rods. Antibodies raised against Trypanosoma cruzi that also interact with beta1-adrenergic receptor blocked light stimulation of cGMP-phosphodiesterase in bovine rod membranes. The specificity from the antibody-rhodopsin interaction was confirmed by Western blot analysis and antigenic competition experiments. Our results suggest an immunomediated rhodopsin blockade. T. cruzi infection probably induces an autoimmune response against rhodopsin in the chronic phase of Chagas' disease through a molecular mimicry mechanism similar to that described previously on cardiac human beta1-adrenergic and M2-cholinergic receptors, all related to the same subfamily of G-protein-coupled receptors.

Alfa-enolasa: a novel autoantigen in patients with premature ovarian failure Sundblad, Victoria; Bussmann, Leonardo Edmundo; Chiauzzi, Violeta Alicia; Pancholy, Vijay; Charreau, Eduardo Hernan Although controversial, the presence of circulating antiovarian antibodies (AOA) may be considered a marker of autoimmune premature ovarian failure (POF). The purpose of the present work was to evaluate the presence of AOA in POF patients, and to identify a possible autoantigen in order to develop a reliable diagnostic tool that might help to determine the real prevalence of autoimmune POF.