Intimal thickenings in the inferior epigastric artery and coronary bypass

OBJECTIVE: To investigate the relationship between the inferior epigastric artery and the development of pathological intimal thickenings. MATERIAL AND METHODS: The inferior epigastric artery structure was studied with conventional histology techniques, histochemistry, immunohistochemistry and morphometry. RESULTS: The inferior epigastric artery develops 2 types of intimal thickenings: physiological and pathological. In our study, the pathological or atherosclerotic thickenings in this artery were not very common: they were present in 28% of the analysed cases. Vessel flow was not affected as shown by the intimal thickness index (I.T.I.) and the lumen reduction index (L.R.I.). The alpha-actin technique confirmed the role of the smooth muscle cells in the genesis of the thickening. Furthermore, histochemistry demonstrated that the extracellular matrix is rich in highly sulphated acid mucopolysaccharides. CONCLUSION: The inferior epigastric artery seems to be a good candidate for grafting in coronary revascularization because of the low susceptibility to thickening of its intima and the minimal repercussion on its blood flow.     

Alternative splicing regulates the nuclear or cytoplasmic localization of dystrophin Dp71

The subcellular distribution of Dp71 isoforms alternatively spliced for exon 71 and/or 78 was examined. The cDNA sequence of each variant was fused to the C-terminus of the green fluorescent protein and the constructs were transfected transiently in the cell lines HeLa, C2C12 and N1E-115. The subcellular distribution of the fused proteins was determined by confocal microscope analysis. The Dp71 isoform lacking the amino acids encoded by exons 71 and 78 was found exclusively in the cytoplasm whereas the variants containing the amino acids encoded by exon 71 and/or exon 78 show a predominant nuclear localization. The nuclear localization of Dp71 provides a new clue towards the establishment of its cellular function.     

A Bayesian generalized random regression model for estimating heritability using overdispersed count data

Background

Faecal egg counts are a common indicator of nematode infection and since it is a heritable trait, it provides a marker for selective breeding. However, since resistance to disease changes as the adaptive immune system develops, quantifying temporal changes in heritability could help improve selective breeding programs. Faecal egg counts can be extremely skewed and difficult to handle statistically. Therefore, previous heritability analyses have log transformed faecal egg counts to estimate heritability on a latent scale. However, such transformations may not always be appropriate. In addition, analyses of faecal egg counts have typically used univariate rather than multivariate analyses such as random regression that are appropriate when traits are correlated. We present a method for estimating the heritability of untransformed faecal egg counts over the grazing season using random regression.

Results

Replicating standard univariate analyses, we showed the dependence of heritability estimates on choice of transformation. Then, using a multitrait model, we exposed temporal correlations, highlighting the need for a random regression approach. Since random regression can sometimes involve the estimation of more parameters than observations or result in computationally intractable problems, we chose to investigate reduced rank random regression. Using standard software (WOMBAT), we discuss the estimation of variance components for log transformed data using both full and reduced rank analyses. Then, we modelled the untransformed data assuming it to be negative binomially distributed and used Metropolis Hastings to fit a generalized reduced rank random regression model with an additive genetic, permanent environmental and maternal effect. These three variance components explained more than 80 % of the total phenotypic variation, whereas the variance components for the log transformed data accounted for considerably less. The heritability, on a link scale, increased from around 0.25 at the beginning of the grazing season to around 0.4 at the end.

Conclusions

Random regressions are a useful tool for quantifying sources of variation across time. Our MCMC (Markov chain Monte Carlo) algorithm provides a flexible approach to fitting random regression models to non-normal data. Here we applied the algorithm to negative binomially distributed faecal egg count data, but this method is readily applicable to other types of overdispersed data.     

1H‐NMR Based Metabolomics Profiling of Citrus Juices Produced in Veracruz,México

This study describes the ¹H‐NMR‐based metabolomics profiling of juices from citrus fruits harvested in the state of Veracruz, México. The hydrophilic profile of commercial lemons (Agrio and Persian), tangerines (Fremont and Mónica), oranges (Valencia and Washington Navel), and grapefruits (Red Ruby and Rio Red) was determined. According to our results, 35 metabolites were identified in the ¹H‐NMR profiling. The statistical differences obtained by PCA and OPLS‐DA revealed that specific amino acids, sugars, and organic acids were differential metabolites in the species and cultivars studied. High endogenous levels of sucrose (10–190 mM), α‐glucose, β‐glucose (α‐ and β‐isomers, 40–205 mm ), and fructose (36–170 mm ) were detected in the juices of grapefruits, oranges, and tangerines, whereas citric acid (40–530 mm ) was the principal organic acid in the juices of lemons. To calculate the specific amounts of metabolites from these species and their cultivars, the results were finely analyzed using the qNMR method. According to these calculations, Valencia oranges had the highest concentration of ascorbic acid (>2 mm ). The described ¹H‐NMR method is highly reproducible, inexpensive, and highly robust in comparison to other analytical methods used to determine the hydrophilic profile of citrus juices.     

Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells

Background

Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils.

Purpose

In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells.

Methods

We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells.

Results

Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered.

Conclusion

Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells.     

Planning adaptation to climate change in fast-warming marine regions with seafood-dependent coastal communities

Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and co-developing adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.     

Distribution of life cycle stages in a lithophytic and epiphytic orchid

Density-dependent processes may have multiple effects on populations, which among other things include the regulation of population abundance and of the relative distribution of life-cycle stages within populations. The epiphytic habitat is often characterized as highly ephemeral and therefore epiphytic orchid populations may never achieve density-dependent regulation. In this study, we investigated the potential for density-dependent regulation in epiphytic and lithophytic orchids by examining the association between seedlings, juvenile and adult life-history stages in the Caribbean endemic orchid,Lepanthes rupestris in a cross-sectional study of 179 populations surveyed in the Luquillo National Forest along a riparian area where it is locally abundant. Under density-dependent regulation we expected a negative association between the ratio of seedling/adults and juveniles/adults and total population density. Population density was in the range of 140 individuals per m², however patch sizes were small and mostly limited to less than 0.5 m² with a maximum of 3 m². We found no evidence of reduction of the ratio of seedlings or juveniles to adults as population size increased in either tree or boulder populations suggesting negative density dependence for population regulation inL. rupestris is either rare or occurs at even higher densities than those measured here. Moreover, we found positive (although weak) relationship between the ratio of seedlings and juveniles to adults and population size, suggesting that facilitation may be occurring.     

The balance between cell division and endoreplication depends on E2FC-DPB, transcription factors regulated by the ubiquitin-SCFSKP2A pathway in Arabidopsis

The balance between cell proliferation, cell cycle arrest, and differentiation needed to maintain the organogenetic program depends on the coordination of gene expression, posttranslational modification, and specific proteolysis of cell cycle regulators. The G1/S and G2/M transitions are critical checkpoints controlled, in part, by cyclin-dependent kinases in the retinoblastoma (RBR)/E2F/DP pathway. Arabidopsis thaliana DPB is regulated by phosphorylation and targeted to proteasome-mediated proteolysis by the SCF(SKP2A) complex. In addition, DPB interacts in vivo with E2FC, because ectopic coexpression of E2FC and DPB produces severe developmental defects. To understand E2FC/DPB heterodimer function, we analyzed the effect of reducing E2FC mRNA levels with RNA interference. The e2fc-R plants developed organs with more but smaller cells and showed increased cell cycle marker gene expression and increased proliferative activity in developing leaves, meristems, and pericycle cells. This last feature produces plants with more lateral roots, consistent with an E2FC role in restricting lateral root initiation. The e2fc-R plants also show marked reductions in ploidy levels of mature leaves. These results indicate that the transition from cell division to the endocycle is sensitive to different pathways, E2FC/DPB being one of them. Our results show that E2FC/DPB is a key factor in controlling the balance between cell proliferation and the switch to the endocycle program.     

Neuronal differentiation modulates the dystrophin Dp71d binding to the nuclear matrix

The function of dystrophin Dp71 in neuronal cells remains unknown. To approach this issue, we have selected the PC12 neuronal cell line. These cells express both a Dp71f cytoplasmic variant and a Dp71d nuclear isoform. In this study, we demonstrated by electron and confocal microscopy analyses of in situ nuclear matrices and Western blotting evaluation of cell extracts that Dp71d associates with the nuclear matrix. Interestingly, this binding is modulated during NGF-induced neuronal differentiation of PC12 cells with a twofold increment in the differentiated cells, compared to control cells. Also, distribution of Dp71d along the periphery of the nuclear matrix observed in the undifferentiated cells is replaced by intense fluorescent foci localized in the center of the nucleoskeletal structure. In summary, we revealed that Dp71d is a dynamic component of nuclear matrix that might participate in the nuclear modeling occurring during neuronal differentiation.