A low-cost paper-based platform for fast and reliable screening of cellular interactions with materials.

A paper-based platform was developed and tested for studies on basic cell culture, material biocompatibility, and activity of pharmaceuticals in order to provide a reliable, robust and low-cost cell study platform. It is based upon a paper or paperboard support, with a nanostructured latex coating to provide an enhanced cell growth and sufficient barrier properties. Wetting is limited to regions of interest using a flexographically printed hydrophobic polydimethylsiloxane layer with circular non-print areas. The nanostructured coating can be substituted for another coating of interest, or the regions of interest functionalized with a material to be studied. The platform is fully up-scalable, being produced with roll-to-roll rod coating, flexographic and inkjet printing methods. Results show that the platform efficiency is comparable to multi-well plates in colorimetric assays in three separate studies: a cell culture study, a biocompatibility study, and a drug screening study. The color intensity is quantified by using a common office scanner or an imaging device and the data is analyzed by a custom computer software without the need for expensive screening or analysis equipment.

Isolation on a remote island: genetic and morphological differentiation of a cosmopolitan odonate.

Although low levels of genetic structure are expected in highly widespread species, geographical and/or ecological factors can limit species distributions and promote population structure and morphological differentiation. In order to determine the effects of geographical isolation on population genetic structure and wing morphology, 281 individuals of the cosmopolitan odonate Pantala flavescens were collected from four continental (Central and South America) and five insular sites (Polynesian islands and the Maldives). COI sequences and eight microsatellite loci were used to characterize genetic diversity and genetic structure between and within locations. Linear and geometric morphometry were used to evaluate differences in the size and shape of wings. Genetic analysis showed a global genetic difference between the continental and insular sites. American locations did not show genetic structure, even in locations separated by a distance of 5000 km. Easter Island showed the lowest values of genetic diversity (mainly mitochondrial diversity) and the highest values of genetic differences compared to other insular and continental sites. Individuals from Easter Island showed smaller forewings, a different abdomen length to thorax length ratio, and a different configuration of anal loop in the hindwings. Thus, the greater isolation, smaller area, and young geological age seem to have determined the genetic and morphological differences in P. flavescens of Easter Island, where selection could promote a loss of migratory behavior and may improve other life history traits, such as reproduction. This work provides new insight into how microevolutionary processes operate in isolated populations of cosmopolitan species.

Differential gene expression revealed with RNA-Seq and parallel genotype selection of the ornithine decarboxylase gene in fish inhabiting polluted areas.

How organisms adapt to unfavorable environmental conditions by means of plasticity or selection of favorable genetic variants is a central issue in evolutionary biology. In the Maipo River basin, the fish Basilichthys microlepidotus inhabits polluted and non-polluted areas. Previous studies have suggested that directional selection drives genomic divergence between these areas in 4% of Amplified Fragment Length Polymorphism (AFLP) loci, but the underlying genes and functions remain unknown. We hypothesized that B. microlepidotus in this basin has plastic and/or genetic responses to these conditions. Using RNA-Seq, we identified differentially expressed genes in individuals from two polluted sites compared with fish inhabiting non-polluted sites. In one polluted site, the main upregulated genes were related to cellular proliferation as well as suppression and progression of tumors, while biological processes and molecular functions involved in apoptotic processes were overrepresented in the upregulated genes of the second polluted site. The ornithine decarboxylase gene (related to tumor promotion and progression), which was overexpressed in both polluted sites, was sequenced, and a parallel pattern of a heterozygote deficiency and increase of the same homozygote genotype in both polluted sites compared with fish inhabiting the non-polluted sites was detected. These results suggest the occurrence of both a plastic response in gene expression and an interplay between phenotypic change and genotypic selection in the face of anthropogenic pollution.

Heavy Metal Content in Chilean Fish Related to Habitat Use, Tissue Type and River of Origin.

In this study, we analyze the concentration of ten metals in two freshwater fish-the benthic catfish Trichomycterus areolatus and the limnetic silverside Basilichthys microlepidotus-in order to detect possible accumulation differences related to fish habitat (benthic or pelagic), tissue type (gill, liver and muscle), and the river of origin (four different rivers) in central Chile. The MANOVA performed with all variables and metals, revealed independent effects of fish, tissue and river. In the case of the fish factor, Cu, Cr, Mo and Zn showed statistically higher concentrations in catfish compared with silverside for all tissues and in all rivers (p < 0.05). In the case of the tissue factor, Al, Cr, Fe and Mn had statistically higher concentrations in liver and gills than in muscle (p < 0.05). For the river effect, the analysis showed higher concentrations of Cr, Mn and Pb in the Cogoti river and the lower concentrations in the Recoleta river. These results suggest that not all metals have the same pattern of accumulation; however, some metals tend to accumulate more in readily catfish, probably due to their benthic habit, and in liver and gill tissue, probably as a result of accumulation from food sources and respiration.

Effects of a Dam Reservoir on the Distribution of Heavy Metals in Two Chilean Native Freshwater Fish Species.

In order to determine the effect of a dam on metal concentrations in riverine fish species, we studied fish inhabiting the influent (Cachapoal River) and effluent (Rapel River) of the Rapel Reservoir in central Chile. Heavy metals were quantified in gills, liver and muscle of the catfish Trichomycterus areolatus and the silverside Basilichthys microlepidotus. Also, the bioaccumulation index (BAI) was estimated by considering heavy metal concentrations obtained from water and sediment. Results showed the presence of Al, Cu, Fe, Mn, Pb and Zn in the fish organs. The analysis showed high metal concentrations in catfish inhabiting the influent compared to those collected in the effluent. These results indicate a possible filter effect of the dam for most of the metals identified in the fish organs, because metal concentrations decreased in the effluent. Finally, catfish exhibited a larger BAI for most metals analyzed.

Phylogenetic and phylogeographic analysis of the genus Orestias (Teleostei: Cyprinodontidae) in the southern Chilean Altiplano: the relevance of ancient and recent divergence processes in speciation.

This study presents phylogenetic molecular data of the Chilean species of Orestias to propose an allopatric divergence hypothesis and phylogeographic evidence that suggests the relevance of abiotic factors in promoting population divergence in this complex. The results reveal that diversification is still ongoing, e.g. in the Ascotán salt pan, where populations of Orestias ascotanensis restricted to individual freshwater springs exhibit strong genetic differentiation, reflecting putative independent evolutionary units. Diversification of Orestias in the southern Altiplano may be linked to historical vicariant events and contemporary variation in water level; these processes may have affected the populations from the Plio-Pleistocene until the present.

Association of the estrogen receptor alpha gene polymorphisms with osteoporosis in the Mexican population.

The estrogen receptor gene (ER alpha) has been implicated in the development of osteoporosis. In this study, the association of two ER alpha gene polymorphic markers (a TA dinucleotide repeat and a single nucleotide polymorphism, G2014A) with osteoporosis was tested in 70 osteoporotic women, 70 non-osteoporotic women and 500 subjects from the Mexican population. According to the genetic analysis of the Mexican population using eight unlinked polymorphic markers, we found that our population is structured into three subpopulations; therefore, the allele-phenotype relationship was analyzed with a statistical method that considered population stratification. We found that the G2014A polymorphism is associated with the presence of osteoporosis while the TA dinucleotide repeat is not. The G allele and the GG genotype frequencies of the G2014A marker were significantly higher in osteoporotic than in non-osteoporotic women. Likewise, subjects bearing the G allele in heterozygous or homozygous displayed lower values for lumbar bone mineral density and T score than those who did not present any G allele. The effect of confounders for osteoporosis on the association of G allele-osteoporosis was ruled out. In summary, we conclude that the G2014 polymorphism may become a useful marker for genetic studies of osteoporosis in the Mexican population.

Stable genetic polymorphism in heterogeneous environments: balance between asymmetrical dispersal and selection in the acorn barnacle.

Elucidating the processes responsible for maintaining polymorphism at ecologically relevant genes is intimately related to understanding the interplay between selection imposed by habitat heterogeneity and a species' capacity for dispersal in the face of environmental constraints. In this paper, we used a model-based approach to solve equilibria of balanced polymorphism, given values of fitness and larval dispersal among different habitats in the acorn barnacle Semibalanus balanoides from the Gulf of St Lawrence. Our results showed that allele frequencies observed at both MPI* and GPI* loci represented stable equilibria, given empirical estimates of fitness values, and that considerably more larvae dispersed from one region (north) to the other (south) than vice versa. Dispersal conditions were predicted to be similar for the maintenance of polymorphism at both loci. Moreover, the values of asymmetrical dispersal required by the model to reach stable equilibria were compatible with empirical estimates of larval dispersal and oceanic circulation documented in this system. Overall, this study illustrated the usefulness of a modified and computable version of Bulmer's model (1972) in order to test hypotheses of balanced polymorphism resulting from interactions between spatial selection and asymmetrical dispersal.

Regional variation in the spatial scale of selection at MPI* and GPI* in the acorn barnacle Semibalanus balanoides (Crustacea).

Elucidating the ecological processes by which adaptive genetic polymorphism is maintained in heterogeneous environments requires knowledge on the spatial scale at which alternate habitats affect genotype-specific fitness. The general objective of this study was to document patterns of temporal and spatial variation of genetic polymorphism in the acorn barnacle (Semibalanus balanoides) at MPI* and GPI* allozyme loci. A total of 7261 barnacles were sampled in the intertidal at various locations north and south of the Miramichi estuary, New Brunswick, Canada. The results of this study supported the hypothesis that both MPI* and GPI* are under the effect of strong directional selection south of the Miramichi, whereas neutrality cannot be ruled out at sampling sites located north of the estuary. Comparisons between this study and previous ones also question the generality of current hypotheses regarding ecological processes that are responsible for maintaining polymorphism at MPI* and GPI* in the acorn barnacle.

Otras alternativas técnicas en el transplante hepático heterotópico experimental / Other technical alternatives in the experimental heterotopic hepatic transplantation

Presentamos nuestra técnica en el transplante hepático heterotópico en perros. Antes de anastomosar las cavas a nivel infrahepático, colocamos un by-pass endocavo multifenestado, para evitar problemas de drenaje venoso del hígado. Este catéter intracavo permite maniobrar dirigidas a obviar los riesgos de sangramiento y alteraciones electrolíticas y cardiovasculares

Modificaciones al modelo experimental de trasplante hepático ortotópico / Modifications to the experimental model of orthotopic liver transplantation

Se presenta nueva técnica en trasplantes hepáticos experimentales en perros. Utilizando, como variantes del modelo clásico de Starzl, dos by-pass, uno portoyugular y otro endocavo, logramos reducir el tiempo total de clampeo y de las cavas, con las consiguientes menores alteraciones cardiovasculares, electrolíticas y riesgo de sangramiento

Epidemiologia del cancer ginecologico Factores de riesgo. / Epideiology of gynecological cancer. Risk factors

Se presenta una investigacion sobre "estudios de grupos de pacientes y grupos de comparacion" relacionados con la epidemiologia del cancer ginecologico para determinar la validez de los factores de riesgo Se estudian 1.497 mujeres - 724 afectas de cancer -, de los hospitales ginecobstetricos sur y norte, clinicoquirurgico y oncologico de Santiago de Cuba, y 800 mujeres sanas, en el periodo comprendido de 1973 a 1978. Los indicadores utilizados fueron: grupos de edades, edad del primer contacto sexual, del primer parto, paridad, lactancia y su duracion, menarquia, menopausia, obesidad, diabetes, hipertension arterial y otros. Se concluye que las primeras relaciones sexuales, el primer parto por debajo de los 20 anos y la multiparidad constituyen factores de riesgo para el cancer de cuello; que la lactancia no resulta protectora del cancer de mama y que la obesidad influye en la aparicion del adenocarcinoma de endometrio. No se hallo relacion entre los factores de riesgo y las restantes localizanciones de la enfermedad. Los metodos estadisticos utilizados para la comparacion fueron las pruebas de chi cuadrado y t de Student

Epidemiologia del cancer ginecologico Factores de riesgo. / Epidemiology of gynecological cancer. Risk factors

Se presenta una investigacion sobre "estudios de grupos de pacientes y grupos de comparacion" relacionados con la epidemiologia del cancer ginecologico para determinar la validez de los factores de riesgo Se estudian 1.497 mujeres - 724 afectas de cancer -, de los hospitales ginecobstetricos sur y norte, clinicoquirurgico y oncologico de Santiago de Cuba, y 800 mujeres sanas, en el periodo comprendido de 1973 a 1978. Los indicadores utilizados fueron: grupos de edades, edad del primer contacto sexual, del primer parto, paridad, lactancia y su duracion, menarquia, menopausia, obesidad, diabetes, hipertension arterial y otros. Se concluye que las primeras relaciones sexuales, el primer parto por debajo de los 20 anos y la multiparidad constituyen factores de riesgo para el cancer de cuello; que la lactancia no resulta protectora del cancer de mama y que la obesidad influye en la aparicion del adenocarcinoma de endometrio. No se hallo relacion entre los factores de riesgo y las restantes localizanciones de la enfermedad. Los metodos estadisticos utilizados para la comparacion fueron las pruebas de chi cuadrado y t de Student