1,720,960 research outputs found
Back to the water: Tongue morphology associated to contrasting lifestyles in two Andean frogs of the genus Telmatobius
No full textThe evolution of the tongue in tetrapods is associated with feeding in the terrestrial environment. This study analyzes the tongue morphology of two closely related frog species, Telmatobius oxycephalus and T. rubigo, which exhibit contrasting feeding mechanisms. Telmatobius oxycephalus, a semi-aquatic species, relies on its tongue to capture terrestrial prey whereas T. rubigo, a secondarily aquatic species, uses suction feeding not involving the tongue. Through anatomical, histological and scanning electron microscopy analyses, we revealed remarkable differences in tongue morphology between these species. Telmatobius oxycephalus exhibits a well-developed tongue whose dorsal epithelium has numerous and slender filiform papillae. The epithelial cells of the papillae are protruded and have a complex array of microridges. In contrast, T. rubigo possesses a reduced tongue with flat and less numerous filiform papillae. The epithelial cells are completely flat and lack microridges. These findings highlight the remarkable adaptability of lingual morphology in Telmatobius to respond to the contrasting ecological niches and prey capture mechanisms. This study sheds light on the relationship between tongue shape and the different functional demands, contributing to our understanding of the evolution of prey capture mechanisms in amphibians.Fil: Barrionuevo, Jose Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Fundación Miguel Lillo; ArgentinaFil: Pucci Alcaide, Franco Jose. Fundación Miguel Lillo. Dirección de Zoología; Argentin
Testicular histology of Anurans that deposit eggs out of the water
Full text linkAnuran amphibians show the largest diversity of amphibian reproductive modes,many of which imply egg deposition out of the water. This kind of egg depositionrequires specialisations to avoid egg desiccation. Physiological, anatomical and ethological traits integrate to define these modes. In particular, morphological featuresof the urogenital system correlate with these reproductive modes and the environmental conditions where egg-laying occurs. In this study, we describe the testicularhistology and spermatogenesis of the nest-building frog Leptodactylus latinasus, andwe compare it with other species that breed out of water. We found variations in testis size, the thickness of interstitial tissue, tunica albuginea, and peritubular tunics,flagellum length, and in the shape and size of the spermatozoal nucleus. Certainspecifics? characters differed at the species level, but not between families. Suchvariation could be an indicator of spermatozoal performance and environmentalconstraints under which fertilisation takes place.Fil: Pucci Alcaide, Ana. Instituto de Morfología Animalfundación Miguel Lillotucumán; ArgentinaFil: Pucci Alcaide, Franco Jose. Instituto de Morfología Animalfundación Miguel Lillotucumán; ArgentinaFil: Michel, Adriana Azucena. Instituto de Morfología Animalfundación Miguel Lillotucumán; ArgentinaFil: Ponssa, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin
The Vesicles of Phyllomedusa sauvagii (Anura: Hylidae) Nest
Full text linkPhyllomedusa sauvagii lays its eggs surrounded by peculiar vesicles in nests made with tree leaves and, until now, the function of these vesicles was thought to be for maintaining moisture. The histomorphological and histochemical analysis of the oviduct of individuals in ovulatory period, and the study of the vesicles in the oviduct, ovisac and in the nest, showed unexpected results. Vesicles originate from glycoconjugates, proteins and lipids secreted in the PCP and PC and organized in the oviductal lumen and, according to their content, it is possible to recognize at last four types. Furthermore, both in the ovisac and in the nest, vesicles show peculiar relationships with oocites/eggs/embryos through specific communication channels, showing the existence of more complex interactions than previously thought.Fil: Pucci Alcaide, Ana. Fundación Miguel Lillo; ArgentinaFil: Alcaide, María Fernanda. Fundación Miguel Lillo; ArgentinaFil: Pucci Alcaide, Franco. Fundación Miguel Lillo; ArgentinaFil: Lavilla, Esteban Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Fundación Miguel Lillo; Argentin
Morphometric Variations in the Skin Layers of Frogs: An Exploration Into Their Relation With Ecological Parameters in Leptodactylus (Anura, Leptodactylidae), With an Emphasis on the Eberth-Kastschenko Layer
Full text linkLeptodactylus is a genus of frogs known to live in diverse habitats and to show both aquatic and terrestrial breeding habits. We studied 21 species of Leptodactylus to explore whether skin structure specialization relates to habitats and habit variation. Morphometric analyses of the skin thickness revealed that phylogeny has a strong influence on variations in the thickness of the epidermis, stratum spongiosum, Eberth-Kastschenko layer, and stratum compactum, while habitat and habits display no significant correlation. The optimization of the phylogenetic hypothesis suggested that a pattern of intermediate values for skin layer thickness are plesiomorphic for this group. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1895–1909, 2017.Fil: Ponssa, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Barrionuevo, Jose Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Pucci Alcaide, Franco. Fundación Miguel Lillo; ArgentinaFil: Pucci Alcaide, Ana. Fundación Miguel Lillo; Argentin
Biological activity of coumarins against Spodoptera frugiperda (Lepidoptera: Noctuidae)
No full textIn this work, we evaluated the activity of coumarins against larvae Spodoptera frugiperda in a group of compounds (1-7) purchased from SIGMA-ALDRICH (96% purity, as informed by the anufacturer) and a group of coumarin derivatives (compounds 8-15) synthesized according to uitable chemistry procedures. Coumarins were synthesized by the Pechmann method under olvent-free conditions sing a bulk Keggin heteropolyacid. The compounds represent a valuable resource for future studies of plant chemical defense. Results indicate that coumarins: (12) 7-methyl-3,4-dimethyl-2H-chromen-2-one, (14) 7-hydroxy-3,4 dimethyl-2H-chromen-2-one, and (15) 4-methyl-2H-benzo[h]-chromen-2- ne have highly significant insect growth regulatory activity. Furthermore, sublethal effects were bserved such as pupal mortality and adult deformities. Compounds (13) 4,6,7-trimethyl-2H-hromen-2-one and (14) 7-hydroxy-3,4 dimethyl-2H-chromen-2-one caused pupal mortality higher than 40%. The quantitative structure-activity relationships were determined using the available data with the urpose of predicting the toxicity activity of a number of structurally related coumarins. A molecular structure and biological activity relationship is suggested. The observed effects were in part produced by severe alterations of the epithelial cells of the midgut.Fil: Corzo, Fernando Livio. Universidad Nacional de Chilecito; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruiz, D. M.. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Centro de Investigación de Sanidad Vegetal; ArgentinaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Pucci Alcaide, Franco Jose. Instituto de Morfologia Vegetal ; Direccion de Botanica ; Fundacion Miguel Lillo;Fil: Gilabert Valero, José Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentin
Preliminary assessment of in vivo safety of potentially probiotic lactic acid bacteria for American bullfrog culture
Full text linkThe effect of the administration of beneficial lactic acid bacteria (LAB): Lactococcus lactis CRL 1584, L. lactis CRL 1827, Enterococcus gallinarum CRL 1826 and combined CRL 1584+ CRL 1826 on the development of bullfrog embryos from the hatching stage until 31 days (tadpole) was evaluated. In vitro assays indicated that 103, 106 and 109 CFU mL−1 single LAB strains remained viable until 24 h in 10% Ringer. Around 109 CFU mL−1 LAB (individually and combined) were used in an experimental design built to evaluate their effect when administrated at different intervals (three 7-day cycles with 5-day rest periods in between) to embryos until day 31. The highest potentially beneficial population (LAB) numbers were detected in the LAB-treated groups. All the LAB-treatments increased it and were significantly higher than the controls. Although the highest, potentially pathogenic, population (Red-Leg Syndrome-RLS-related pathogens) numbers were detected in the control and the lowest in the CRL 1584+ CRL 1826-treated group, they did not differ significantly. Stereoscopic studies showed no malformations in any LAB-treated group and all the specimens reached the same stage of their biological cycle with a survival >94%. The histological structure of target organs for RLS-associated pathogens (intestine and skin) and stomach was not affected and the spleen was developed. Only the LAB-treated groups showed microorganisms associated with the intestinal mucus, without inflammatory reaction in the lamina propria. This is the first report on the evaluation of the absence of adverse effects after LAB administration to bullfrog embryos using indigenous microorganisms.Fil: Pasteris, Sergio Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Montel Mendoza, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Llanos, Ricardo J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Pucci Alcaide, Franco J.. Fundación Miguel Lillo; ArgentinaFil: Nader, Maria Elena Fatima. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentin
HISTOLOGíA DEL OVARIO Y OVIDUCTO DE LA RANA DE DESARROLLO DIRECTO Oreobates discoidalis (ANURA: STRABOMANTIDAE)
Full text linkOreobates discoidalis es un anuro que se reproduce en entornos húmedos y protegidos, depositando sus huevos relativamente grandes directamente en tierra y exhibiendo desarrollo directo. En este estudio, se describe la histología de los órganos sexuales de hembras maduras durante el periodo reproductivo de esta especie. Las hembras de O. discoidalis presentan ovarios compuestos por un solo lóbulo, así como folículos ováricos tipo 3 con sectorización citoplasmática debido a la acumulación de plaquetas vitelinas. En algunos de estos folículos, el epitelio es de tipo cuboidal, y la teca está formada por dos capas en los folículos ováricos tipo 3. En cuanto al oviducto, se observa una predominancia de glicoconjugados ácidos con una distribución laberíntica, organizados de manera fibrilar y granular. Este estudio ha permitido identificar características particulares en la arquitectura de los compuestos glucídicos y en el seguimiento de los compuestos oviductales en hembras de O. discoidalis, las cuales serían adecuadas para un modo de puesta fuera del agua.Oreobates discoidalis is an anuran that reproduces in moist and sheltered habitats, laying relatively large eggs directly on land, and undergoing direct development. In this study, we describe the histology of the sexual organs of mature females during the reproductive period. Our observations reveal ovaries consisting of a single lobe, type 3 ovarian follicles exhibiting sectorization of the cytoplasm due to the accumulation of vitelline platelets, with some of these follicles exhibiting cubic epithelium, and theca formed by two layers in type 3 and 4 ovarian follicles. The oviduct is dominated by acid-type glycoconjugates exhibiting a labyrinthine distribution, organized in a fibrillar and granular manner. This study has revealed distinctive features in the architecture of glucid compounds and the monitoring of oviductal compounds in females of O. discoidalis. These characteristics would be suitable for a water-independent mode of reproduction.Fil: Pucci Alcaide, Ana. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Pucci Alcaide, Franco Jose. Fundación Miguel Lillo; ArgentinaFil: Ponssa, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Michel, Adriana A.. Fundación Miguel Lillo; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
High fat diet induces microvesicular steatosis in an experimental model of metabolic syndrome without dislipidemia
Full text linkLa enfermedad del hígado graso no alcohólico (NAFLD) inducida por dietas ricas
en grasas es considerada actualmente el componente hepático del síndrome
metabólico, sin embargo su fisiopatología es actualmente objeto de controversia. El
objetivo del presente estudio fue evaluar los cambios morfológicos hepáticos y su
relación con componentes del síndrome metabólico en un modelo de conejo alimentado con una dieta rica en grasas. Los animales (n=24) fueron separados en dos grupos: uno recibió una dieta control (DC, n=12) y el otro una DC enriquecida con grasa al 10 % (DG, n=12) durante 12 semanas. Al final del periodo de alimentación se realizaron test de tolerancia a la glucosa y determinaciones de presión arterial media (PAM), frecuencia cardiaca (FC), insulina, colesterol total, HDL-C, LDL-C, triglicéridos, sustancias reactivas del ácido tiobarbitúrico (TBARS) y relación glutatión reducido/oxidado (GSH/GSSH). Se extrajeron grasas de la zona visceral abdominal y el hígado y se pesaron. Se realizó análisis histológico de cortes de hígado. Los conejos alimentados con DG presentaron aumento de peso corporal, de grasa visceral abdominal, de PAM, FC, insulina plasmática. No se observaron diferencias en los lípidos, TBARS ni GSH/GSSH con respecto a los DC. El análisis histológico mostró la presencia de esteatosis microvesicular. En conclusión, una DG generó un modelo de síndrome metabólico caracterizado por una alteración temprana hepática compatible con esteatosis microvesicular. Considerando que en este modelo los niveles de lípidos plasmáticos y los parámetros de estrés oxidativo fueron normales, la resistencia a la insulina sería el biomarcador temprano de NAFLD en el síndrome metabólico.High fat diet induces non-alcoholic fatty liver disease that is now considered to be
the hepatic component of the metabolic syndrome. However, its physiophatology
remains a controversial subject. The present study was carried out to evaluate
morphological changes in the liver and its association with known components of
metabolic syndrome in a rabbit model. Animals (n=24) were fed either on regular chow (CD; n=12) or high fat diet 10 % (HFD, n=12). After 12 weeks, body weight, visceral abdominal fat, glucose tolerance test, mean arterial blood pressure and heart rate were significantly increased in rabbits fed on HFD. Plasma levels of total cholesterol, LDLcholesterol, HDL-cholesterol, triglycerides, glutathione reduced/glutathione oxidized ratio and thiobarbituric acid reactive substances were similar in both diet groups. Insulin from plasma and HOMA index were higher in rabbis fed on HFD. Histological analysis showed hepatic microvesicular steatosis in this obesity model. In conclusion, HFD induced together with metabolic alterations characterizing the metabolic syndrome early liver injury compatible with microvesicular steatosis. Considering that in such conditions triglycerides levels and oxidative parameters were similar to controls, insulin resistance may be the earlier biomarker of liver injury in the metabolic syndrome.Fil: Scacchic, Fabricio. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Karbiner, María Sofía. Universidad Nacional de Tucumán. Facultad de Medicina; ArgentinaFil: Pucci Alcaide, Franco Jose. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Peral, Maria de Los Angeles. Universidad Nacional de Tucumán. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Jerez, Susana Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin
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