Observaciones sobre las características reproductoras de tres especies de Eunicidae (Polychaeta) asociadas a praderas de la fanerógama marina Posidonia oceanica en el Mar Mediterráneo

Observations on the reproductive features are provided for three species of Eunicidae (Lysidice ninetta Audouin and Milne Edwards, Lysidice collaris Grube and Nematonereis unicornis (Grube)). They all occur in Posidonia oceanica meadows as borers in the sheaths. The material examined was collected during several studies on P. oceanica meadows conducted at various times of the year and in different years along the coasts of Sardinia and the Ischia islands (Tyrrhenian Sea), and Otranto (Southern Adriatic Sea). All individuals of the three species were measured (width 3rd chaetiger, diameter of eyes), and checked for presence of gametes. In each of the females recognized, egg diameter was measured. To integrate the observations, living specimens were collected in March 2003 and reared in the laboratory until August 2003 to check for gamete maturation; mature males were fixed for analysis of the structure of the spermatozoa by transmission electron microscopy (TEM). All three species studied are gonochoric. For both species of Lysidice gametes occurred in individuals with a width greater than 0.8 mm. The overall scarcity of mature males and females observed with respect to the total number of specimens collected is probably due to the dimensional constraint exerted by the sheaths. In Lysidice spp. specimens with small developing oocytes were observed in January-February and reached their maximum diameter between June and August (157 µm). Gametes were located mainly in the posterior part of the body, and an enlargement of the eyes (almost doubled in size) characterized mature specimens close to spawning. N. unicornis is a smaller species, and it is less frequent in Posidonia sheaths than Lysidice spp.; individuals with gametes had a width greater than 0.55 mm. A few mature specimens were observed between March and May with a maximum egg diameter of about 155 µm. In this species maturation of the gametes is coupled with a huge enlargement of the eyes (ten-times larger than in immature individuals), while the posterior part of the body is swollen and full of mature gametes, indicating reproduction by schizogamy. Analysis of mature spermatozoa of the three eunicids revealed a similar morphology, which is that of an “ect-aquasperm” type, typical of many free-spawning species with external fertilization. The nucleus is round and globose (2.5 µm diameter) and the acrosome, slightly different among the three species, has the general shape of a truncate sub-cone.Se discuten algunas caracteristicas generales de la biología de la reproducción de tres especies de poliquetos Eunicidae (Lysidice ninetta Audouin and Milne- Edwards, Lysidice collaris Grube y Nematonereis unicornis (Grube)). Estas especies fueron obtenidas en praderas de Posidonia oceánica, en donde viven asociadas a las escamas de las hojas. El material examinado fue recolectado en diferentes anos y en praderas de P. oceánica distribuidas en la costa de Cerdeña, de la isla de Ischia (Mar Tirreno), y de Otranto (Mar Adriatico Sur). Todos los individuos fueron medidos (anchura del tercer segmento, diámetro de los ojos), y analizados para observar en ellos la presencia de los gametos. En cada hembra se midió el diámetro de los huevos. El desarrollo de otros individuos fue observado en el laboratorio desde Marzo a Agosto 2003 con la finalidad de estudiar la maduración de los gametos. Los machos maduros fueron fijados para el análisis de la ultra-estructura de los espermatozoos al Microscopio Electrónico. Las tres especies estudiadas son gonocóricas (sexos separados). Para las dos especies del genero Lysidice las hembras con huevos siempre se presentaron en individuos superiores en anchura a 0,8 mm. La escasez de hembras y machos maduros en relación al total de individuos está probablemente relacionado con las limitaciones que suponen las dimensiones y espesor de las escamas de Posidonia. Individuos de Lysidice spp. con huevos pequeños en desarrollo se observaron desde Enero-Febrero; los oocitos alcanzaron el máximo diámetro en Junio y Agosto (157 μm). Los gametos se localizaron preferentemente en la parte posterior del cuerpo, y cuando los individuos alcanzaron la madurez, sus ojos se hicieron más anchos (casi el doble en su diámetro). N. unicornis es una especie más pequeña, y menos frecuente en las escamas de Posidonia que Lysidice spp. Los individuos con gametos presentan anchuras superiores a 0,55 mm. Algunos individuos maduros fue observado desde Marzo a Mayo, con diámetros máximos de los huevos de casi 155 μm. En esta especie la madurez se relaciona con un enorme aumento del diámetro de los ojos (diez veces mas anchos que en individuos inmaduros), y en la dilatación de la parte posterior del cuerpo llena de gametos maduros; esta característica indica una reprodución de tipo eschizogámico. La ultra-estructura de los espermatozoos maduros es muy similares en las tres especies de Eunicidae, de tipo”ect-aquasperm”, típicas des especies con fecundación externa. El núcleo (2,5 μm en diámetro) es redondo y globular, y el acrosoma, que es un poco diferente entre las especies, es de forma general en cono truncado. &nbsp

Orthopteran communities (Insecta, Orthoptera) in grasslands of Eastern Humid Chaco, Argentina

Comunidades de ortópteros (Insecta, Orthoptera) en pastizales del Chaco Oriental Húmedo, Argentina.— La diversidad específica y abundancia de las comunidades de Orthoptera fueron estimadas en dos pastizales del Chaco Oriental Húmedo durante el período 2006–2007. El pastizal con pastoreo intenso de ganado bovino y predominancia de especies vegetales nativas se caracterizó por presentar la mayor diversidad específica y el pastizal libre de pastoreo, con predominancia de especies vegetales introducidas, se caracterizó por una mayor abundancia. En total, se registraron 25 especies de ortópteros, siendo la familia Acrididae (Caelifera) la más numerosa y diversa. Staurorhectus longicornis, Dichromorpha australis y Orphulella punctata fueron las especies más abundantes; registrándose las dos últimas durante todo el periodo de muestreo. La mayor abundancia se detectó en el mes de diciembre de 2006. La abundancia de individuos no estuvo correlacionada con ninguna de las variables climáticas consideradas. Palabras clave: Acridoidea, Diversidad específica, Abundancia, Variación temporal y espacial.Comunidades de ortópteros (Insecta, Orthoptera) en pastizales del Chaco Oriental Húmedo, Argentina.— La diversidad específica y abundancia de las comunidades de Orthoptera fueron estimadas en dos pastizales del Chaco Oriental Húmedo durante el período 2006–2007. El pastizal con pastoreo intenso de ganado bovino y predominancia de especies vegetales nativas se caracterizó por presentar la mayor diversidad específica y el pastizal libre de pastoreo, con predominancia de especies vegetales introducidas, se caracterizó por una mayor abundancia. En total, se registraron 25 especies de ortópteros, siendo la familia Acrididae (Caelifera) la más numerosa y diversa. Staurorhectus longicornis, Dichromorpha australis y Orphulella punctata fueron las especies más abundantes; registrándose las dos últimas durante todo el periodo de muestreo. La mayor abundancia se detectó en el mes de diciembre de 2006. La abundancia de individuos no estuvo correlacionada con ninguna de las variables climáticas consideradas. Palabras clave: Acridoidea, Diversidad específica, Abundancia, Variación temporal y espacial.Species diversity and abundance of Orthoptera communities were estimated in two grasslands of Eastern Humid Chaco from 2006 to 2007. The greatest species diversity was recorded in the grassland with intensive livestock grazing and predominance of native plant species, whereas the abundance values were higher in the grassland without grazing and characterized by introduced plant species. In total, 25 Orthoptera species were collected during the study. Acrididae (Caelifera) was the most abundant and diverse family recorded. Staurorhectus longicornis, Dichromorpha australis and Orphulella punctata were the most abundant species; the last two species being recorded during the entire sampling period. The greatest abundance was recorded in December 2006. Abundance did not show any correlation with climatic variables. Key words: Acridoidea, Species diversity, Abundance, Spatial and temporal variation

Un hallazgo en "Barranca Larga" : el yacimiento arqueológico del mojón 747 de la ruta Tinogasta-Belén (provincia de Catamarca)

Fil: Cigliano, Eduardo M.. Universidad Nacional de La Plat

Fructose removal from the diet reverses inflammation, mitochondrial dysfunction, and oxidative stress in hippocampus

Young age is often characterized by high consumption of processed foods and fruit juices rich in fructose, which, besides inducing a tendency to become overweight, can promote alterations in brain function. The aim of this study was therefore to (a) clarify brain effects resulting from fructose consumption in juvenile age, a critical phase for brain development, and (b) verify whether these alterations can be rescued after removing fructose from the diet. Young rats were fed a fructose-rich or control diet for 3 weeks. Fructose-fed rats were then fed a control diet for a further 3 weeks. We evaluated mitochondrial bioenergetics by high-resolution respirometry in the hippocampus, a brain area that is critically involved in learning and memory. Glucose transporter-5, fructose and uric acid levels, oxidative status, and inflammatory and synaptic markers were investigated by Western blotting and spectrophotometric or enzyme-linked immunosorbent assays. A short-term fructose-rich diet induced mitochondrial dysfunction and oxidative stress, associated with an increased concentration of inflammatory markers and decreased Neurofilament-M and post-synaptic density protein 95. These alterations, except for increases in haptoglobin and nitrotyrosine, were recovered by returning to a control diet. Overall, our results point to the dangerous effects of excessive consumption of fructose in young age but also highlight the effect of partial recovery by switching back to a control diet

Assignment of the binding site for Haptoglobin on Apolipoprotein A-I

Haptoglobin (Hpt) was previously found binding the high-density lipoprotein (HDL) Apolipoprotein A-I (ApoA-I) and able to inhibit the ApoA-I-dependent activity of the enzyme Lecithin:Cholesterol Acyl-Transferase (LCAT), which plays a major role in the reverse cholesterol transport. The ApoA-I structure was analyzed for detecting the site bound by Hpt. ApoA-I was treated by cyanogen bromide or hydroxylamine and the resulting fragments, separated by electrophoresis or gel filtration, were tested by Western blotting or ELISA for their ability to bind Hpt. The ApoA-I sequence from Glu113 to Asn184 harbored the binding site for Hpt. Biotinylated peptides were synthesized overlapping such a sequence, and their Hpt binding activity was determined by avidin-linked peroxidase. The highest activity was exhibited by the peptide P2a, containing the ApoA-I sequence from Leu141 to Ala164. Such a sequence contains an ApoA-I domain required for binding cells, promoting cholesterol efflux, and stimulating LCAT. The peptide P2a effectively prevented both binding of Hpt to HDL-coated plastic wells and Hpt-dependent inhibition of LCAT, measured by anti-Hpt antibodies and cholesterol esterification activity respectively. The enzyme activity was not influenced, in the absence of Hpt, by P2a. Differently from ApoA-I or HDL, the peptide did not compete with Hemoglobin for Hpt binding in ELISA experiments. The results suggest that Hpt might mask the ApoA-I domain required for LCAT stimulation, thus impairing the HDL function. Synthetic peptides, able to displace Hpt from ApoA-I without altering its property of binding Hemoglobin, might be used for treatment of diseases associated with defective LCAT function

Inhibition of MELK Protooncogene as an Innovative Treatment for Intrahepatic Cholangiocarcinoma

Background and Objectives: Intrahepatic cholangiocarcinoma (iCCA) is a pernicious tumor characterized by a dismal outcome and scarce therapeutic options. To substantially improve the prognosis of iCCA patients, a better understanding of the molecular mechanisms responsible for development and progression of this disease is imperative. In the present study, we aimed at elucidating the role of the maternal embryonic leucine zipper kinase (MELK) protooncogene in iCCA. Materials and Methods: We analyzed the expression of MELK and two putative targets, Forkhead Box M1 (FOXM1) and Enhancer of Zeste Homolog 2 (EZH2), in a collection of human iCCA by real-time RT-PCR and immunohistochemistry (IHC). The effects on iCCA growth of both the multi-kinase inhibitor OTSSP167 and specific small-interfering RNA (siRNA) against MELK were investigated in iCCA cell lines. Results: Expression of MELK was significantly higher in tumors than in corresponding non-neoplastic liver counterparts, with highest levels of MELK being associated with patients' shorter survival length. In vitro, OTSSP167 suppressed the growth of iCCA cell lines in a dose-dependent manner by reducing proliferation and inducing apoptosis. These effects were amplified when OTSSP167 administration was coupled to the DNA-damaging agent doxorubicin. Similar results, but less remarkable, were obtained when MELK was silenced by specific siRNA in the same cells. At the molecular level, siRNA against MELK triggered downregulation of MELK and its targets. Finally, we found that MELK is a downstream target of the E2F1 transcription factor. Conclusion: Our results indicate that MELK is ubiquitously overexpressed in iCCA, where it may represent a prognostic indicator and a therapeutic target. In particular, the combination of OTSSP167 (or other, more specific MELK inhibitors) with DNA-damaging agents might be a potentially effective therapy for human iCCA

Hallazgos arqueológicos en la Quebrada de Zapagua : (Departamento de Humahuaca, provincia de Jujuy)

Fil: Cigliano, Eduardo M.. Universidad Nacional de La PlataFil: Calandra, Horacio A.. Universidad Nacional de La Plat

LCAT cholesterol esterification is associated with the increase of ApoE/ApoA-I ratio during atherosclerosis progression in rabbit

Apolipoprotein A-I and Apolipoprotein E promote different steps of reverse cholesterol transport, including lecithin-cholesterol acyltransferase stimulation. Our aim was to study the changes in the levels of Apolipoprotein A-I, Apolipoprotein E, and lecithin-cholesterol acyltransferase activity during atherosclerosis progression in rabbits. Quantitative echocardiographic parameters were analyzed in order to evaluate, for the first time, whether atherosclerosis progression in rabbit is associated to apolipoproteins changes and alteration of indices of cardiac function, such as systolic strain and strain rate of the left ventricle. Atherosclerosis was induced by feeding rabbits for 8 weeks with 2 % cholesterol diet. The HDL levels of cholesterol and cholesteryl esters were measured by HPLC. The lecithin-cholesterol acyltransferase activity was evaluated both ex vivo, as cholesteryl esters/cholesterol molar ratio, and in vitro. Apolipoproteins levels were analyzed by ELISA. The HDL levels of cholesterol and cholesteryl esters increased, during treatment, up to 3.7- and 2.5-fold, respectively, compared to control animals. The lecithin-cholesterol acyltransferase activity in vitro was halved after 4 weeks. During cholesterol treatment, Apolipoprotein A-I level significantly decreased, whereas Apolipoprotein E concentration markedly increased. The molar ratio Apolipoprotein E/Apolipoprotein A-I was negatively correlated with the enzyme activity, and positively correlated with both increases in the intima-media thickness of common carotid wall and cardiac dysfunction signs, such as systolic strain and strain rate of the left ventricle. © 2012 University of Navarra