Contribution of population-level phenotypic plasticity to the invasiveness of Zaprionus indianus (Diptera: Drosophilidae)

Zaprionus indianus is a species of fly native to the Afrotropical biogeographic region, which around twenty years ago invaded the American continent. Several studies have shown that local adaptation and phenotypic plasticity of an invasive species in its native range could favour the colonization of new environments. Zaprionus indianus is a holometabolo us generalist polyphagous species that breeds and feeds on the fruits of several different species, which constitute different environments. In this context, we performed a comparative analysis of the phenotypic plasticity of morphological and life history traits in response to seven different breeding environments (i.e. different breeding fruits). The comparison was of native (Africa) vs. invaded ran ge (South America) wild-derived populatio ns. The population-level phenotypic plasticity values related to heterogeneity in different breeding environments for most traits analysed were higher for one of the native range population. This differentiation was also recorded for the ranking across breeding environments of developmental time and wing length mean phenotypic values. In addition, mean phenotypic values pooled across fruit treatments were larger for individuals from the invaded range, which suggests local adaptation. Results define a scenario in which, although not for all the populations analysed, phenotypic plasticity contributes to the invasiveness and local adaptation in native range population of Z. indianus.Fil: Lavagnino, Nicolas Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Imberti, Marcos Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Flaibani, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Ortiz, Victoria Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Fanara, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

Plastic changes in the spinal cord in motor neuron disease.

In the present paper, we analyze the cell number within lamina X at the end stage of disease in a G93A mouse model of ALS; the effects induced by lithium; the stem-cell like phenotype of lamina X cells during ALS; the differentiation of these cells towards either a glial or neuronal phenotype. In summary we found that G93A mouse model of ALS produces an increase in lamina X cells which is further augmented by lithium administration. In the absence of lithium these nestin positive stem-like cells preferentially differentiate into glia (GFAP positive), while in the presence of lithium these cells differentiate towards a neuronlike phenotype (III-tubulin, NeuN, and calbindin-D28K positive). These effects of lithium are observed concomitantly with attenuation in disease progression and are reminiscent of neurogenetic effects induced by lithiumin the subependymal ventricular zone of the hippocampus

The architectural design of urban space and its influence in the communities of parasites in two areas of Buenos Aires City with different circulation dynamic of companion animals

Las excretas de mascotas constituyen un factor de riesgo para la transmisión urbana de zoonosis parasitarias. La abundancia de excretas depende del número de animales, de la posibilidad de acceso y el uso de distintos espacios urbanos. En plazas y parques públicos los animales deambulan acompañados por personas; en parques y jardines privados, el acceso y circulación está restringido a aquellos animales cuyos dueños habitan en el predio. El objetivo de este trabajo fue determinar si las barreras artificiales antropogénicas, condicionantes del tránsito de animales, limitan la dispersión de enteroparásitos. En áreas con desplazamiento restringido (BPLA) y con circulación libre (PP), fueron colectadas heces (BPLA: n=39; PP: n=50) y suelo (BPLA: n=20; PP: n=20) y procesadas por métodos convencionales. La frecuencia de especies en cada ambiente y para cada tipo de muestra fue comparada por el test de Diferencia de Proporciones. Las diferencias entre el número de especies parasitarias en cada matriz ambiental fueron establecidas con el test de Mann-Whitney (alfa=0,05). La similitud de las comunidades fue determinada con el Índice cualitativo de Sorensen (ICS). La proporción de muestras positivas en BPLA fue mayor que en PP (Tierra: 1,0 vs. 0,70; p<0,05 y Heces 0,56 vs. 0,32; p<0,05). En suelo, no se detectaron helmintos; el número de especies por unidad de muestreo fue mayor en BPLA que en PP (Mann-Whitney: U=300; p<0,01) así como la frecuencia relativa de Cryptosporidium sp. (1,0 vs. 0,56; p=0,0006); la riqueza de especies fue similar (ICS=0,8). El confinamiento de animales domésticos urbanos y la restricción de su desplazamiento al espacio verde cercado de su peridomicilio determinan el grado de contaminación fecal del suelo, agravado por el mal hábito higiénico de los propietarios. En estas situaciones, el suelo concentraría algunas formas infectivas y facilitaría su transmisión, realimentando los ciclos de infección y reinfección parasitaria.The presence of canine and feline faeces is a known risk factor for the transmission of zoonotic parasitoses. Their dispersion is tightly linked to the mobility of its hosts and their capability of contaminating such environments with faecal matter, and the latter will be clearly influenced by the ability of entering and exiting such area. Different uses of the urban space where the hosts inhabit may affect precisely that aptitude. It was hypothesized that certain artificial barriers created by urban settings, such as walls and fences, could limit the dispersion of parasitoses as they would limit the mobility of their hosts. The objective of this study was to determine if there were any differences between the communities of intestinal parasites found in excreta and soil samples within two bordering areas, one with restricted circulation (BPLA) and another one without such restrictions (PP). Faecal (BPLA: n=39; PP: n=50) and soil (BPLA: n=20; PP: n=20) samples were collected, processed according to the Willis and the Bacigalupo–Rivero techniques, and diagnosed by optical microscopy of fresh smears, lugol, Kinyoun and modified Ziehl-Neelsen stain. In order to establish statistical differences between the frequencies for all parasite species found in either environment for each sample type, the two populations‟ Difference in Proportions Test was performed. To assess communities‟ similarity, the Sorensen index was utilized and to determine if there were differences between the number of different species per sample the Mann–Whitney test was applied. Statistical differences were found in the total frequency of faeces and soil samples positive for any parasitic form, being higher in BPLA in both cases (p&lt;0, 05). On the other hand, there were no statistical differences for any particular species in any of the two sample types studied, with the exception of Cryptosporidium sp. that proved to be higher in BPLA soil samples (p&lt;0,01). The Sorensen index to compare the similarity among faecal and soil communities found in each urban environment were both 0,8. However, the Mann-Whitney test showed that there were a statistically major number of species per soil sample in BPLA than in PP. When taking these results into consideration, it could be inferred that urban architectonic barriers restricting pet displacements tend toward a raise of faecal contamination, thus increasing the chance of transmission of the studied pathogens, and accelerating cycles of transmission and reinfection.En "Documentos relacionados" se encuentra el link para acceder a la versión en español del artículo.Asociación Parasitológica Argentin

Lamina X of the spinal cord in motor neuron disease

A number of plastic events were described in the spinal cord in the course of amyotrophic lateral sclerosis (ALS). These consist of various morphological effects, involving neurons, glia, and inflammatory cells, as well. Among plastic changes, an increase in neuronal progenitor cells (NPC) occurs within ependymal cells layer of lamina X. This stem cell-like activity is known to be weak in baseline conditions but it is known to increase significantly during spinal cord disorders, when it preferentially generates glial cells, due to the strong gliogenic effect of the spinal cord “milieu”. In the present work, we used immunohistochemistry and electron microscopy to analyze cell number within lamina X at the end stage of disease in the G93A mouse model of ALS in baseline conditions and following chronic lithium administration. These cells were identified by using GFAP, bIII-tubulin, NeuN, and calbindin- D28K immunostaining. In the absence of lithium we observed an increase of lamina X cells in ALS mice with a glial phenotype, while in G93A mice treated with lithium these cells differentiate towards neuronal-like phenotype. These effects of lithium are concomitant with slowed disease progression and are reminiscent of the neurogenetic effects described in the sub-ependymal ventricular zone of the hippocampus. The present data confirm the scarce NPC activity in the intact spinal cord which is enhanced by disease conditions; in the presence of chronic lithium, such increased NPCs differentiate towards a neuron-like rather than a glial phenotype

Effects of Salbutamol on non-NMDA glutamateinduced motor neuron loss

Recent data suggests that catecholamine systems might have a trophic role in the spinal cord. These data are based on the clinical evidence that beta-2 agonists produce a relief in spinal motor neuron disorders. Therefore, in the present study we isolated ventral spinal cord cell cultures and we administered either the beta-2 agonist salbutamol alone or in combination with the beta-2 antagonist butoxamine. These experiments were carried out both in baseline conditions and in the presence of a non-NMDA glutamate shock. In fact, increased extracellular glutamate concentration can be toxic for neuronal cells. Glutamate- mediated excitotoxicity relies on the stimulation of both NMDA and non- NMDA receptors although naturally occurring motor neuron loss is thought to depend on an excess of stimulation of non-NMDA receptors. Therefore, primary cell cultures obtained from the ventral spinal cord of 14-days-old mice embryos were preadministered MK-801, a non-competitive antagonist of NMDA receptors, immediately before the non-NMDA (both kainate and AMPA) receptor agonist kainic acid (KA, 50 and 100 μM for 15 min) either in baseline conditions or in combination with salbutamol (10 μM) and butoxamine (50 μM) administered 30 min before KA. We found that the beta-2 antagonist butoxamine did not produce any effect either alone or in combination with kainate. Although butoxamine prevented the effects induced by the beta-2 agonist salbutamol. In particular, salbutamol prevented non-NMDA-induced motor neuron loss and this effect was abolished by the concomitant administration of butoxamine. When salbutamol was administered alone we detected morphological changes at motor neuron level. We also analysed whether salbutamol administration increased the expression of survival motor neuron protein (SMN, an endogenous molecule which provides protective effect for motor neurons) as a possible mechanism of neuroprotection. Unexpectedly, the protective effects induced by salbutamol were accompanied by a reduction of the SMN, while KA induced an increase in SMN levels. These results lend substance that catecholamine receptors subtype beta-2 protect motor neurons in the short term following glutamate excitotoxicity. It is likely that the paradoxical effects observed for SMN level might be due to the need of a compensatory mechanism (following NMDA) or the reduced level of neuronal stress (following salbutamol). Further studies are in progress to unravel the mechanisms responsible for neuroprotection induced at motor neuron level by catecholamine and beta-2 receptors

Realdo Colombo in the fifth centenary of his birth

The date of birth of Realdo Colombo is still uncertain. However, 1516 is conventionally credited as the year where he was born in Cremona. Colombo’s life can be divided into three periods, according to the cities where he worked: Padua, Pisa and Rome. A talented anatomist, in Padua Colombo became assistant of Andreas Vesalius in 1541. In 1545 he moved to Pisa at the behest of the Grand Duke Cosimo I de’ Medici. Finally, he was invited in Rome by Pope Paul III and became the physician of many important patients, including Michelangelo Buonarroti. He also performed the autopsy on the body of Saint Ignatius of Loyola. In his unique masterpiece, De re anatomica, consisting of 15 books, Colombo reported original observations. He hoped to have a text illustrated by Michelangelo that would have competed with the fabrica of Vesalius, but that purpose did not realize. Indeed, the unique engraving of the volume, published posthumously in 1559, is the frontispiece. The most important anatomical discovery attributed to Colombo is the original description of the pulmonary circulation, based on hundreds of dissections and vivisections. The Galen’s long-standing doctrine of the blood circulation from the right ventricle to the left ventricle through invisible pores of the interventricular septum was definitively rejected. Although two other figures had already described the pulmonary circulation – the thirteenth century Arabic physician Ibn al-Nafis, in the Commentary on Anatomy in Avicenna’s Canon, and the Spanish philosopher Michael Servetus, in the theological book Christianismi restitutio – Colombo seems to have arrived at his conclusions independently. He also understood the function of the cardiac valves. Colombo’s book had a profound effect on William Harvey, when he prepared his lectures on anatomy for the College of Physicians of London, and was determinant for the publication of his description of the blood circulation in De motu cordis (1628). Other anatomical observations are attributed to Colombo. He corrected previous misconceptions, demonstrating that the right kidney is lower than the left, and showing that the lens is in the anterior chamber of the eye. He recognized anatomical variants, such as the presence of palmaris longus muscle, and described congenital malformations, such as the horseshoe kidney. He also seems to have coined the term “placenta” and claimed to have been the first to describe the clitoris and its function

Computational Modelling of Tissue-Engineered Cartilage Constructs

Cartilage is a fundamental tissue to ensure proper motion between bones and damping of mechanical loads. This tissue often suffers damage and has limited healing capacity due to its avascularity. In order to replace surgery and replacement of joints by metal implants, tissue engineered cartilage is seen as an attractive alternative. These tissues are obtained by seeding chondrocytes or mesenchymal stem cells in scaffolds and are given certain stimuli to improve establishment of mechanical properties similar to the native cartilage. However, tissues with ideal mechanical properties were not obtained yet. Computational models of tissue engineered cartilage growth and remodelling are invaluable to interpret and predict the effects of experimental designs. The current model contribution in the field will be presented in this chapter, with a focus on the response to mechanical stimulation, and the development of fully coupled modelling approaches incorporating simultaneously solute transport and uptake, cell growth, production of extracellular matrix and remodelling of mechanical properties.publishe