Journals
2013 EN
Poortvliet Marloes · Longo Gary C. · Selkoe Kimberly
+6 more
In the past decade, the study of dispersal of marine organisms has shifted from focusing predominantly on the larval stage to a recent interest in adult movement. Antitropical distributions provide a unique system to assess vagility and dispersal. In this study, we have focused on an antitropical wrasse genus, S emicossyphus, which includes the California sheephead, S. pulcher , and Darwin's sheephead, S. darwini . Using a phylogenetic approach based on mitochondrial and nuclear markers, and a population genetic approach based on mitochondrial control region sequences and 10 microsatellite loci, we compared the phylogenetic relationships of these two species, as well as the population genetic characteristics within S. pulcher . While S. pulcher and S. darwini are found in the temperate eastern Pacific regions of the northern and southern hemispheres, respectively, their genetic divergence was very small (estimated to have occurred between 200 and 600 kya). Within S. pulcher, genetic structuring was generally weak, especially along mainland California, but showed weak differentiation between Sea of Cortez and California, and between mainland C alifornia and Channel Islands. We highlight the congruence of weak genetic differentiation both within and between species and discuss possible causes for maintenance of high gene flow. In particular, we argue that deep and cooler water refugia are used as stepping stones to connect distant populations, resulting in low levels of genetic differentiation.
Journals
2013 EN
Gioia Claudio · Ricci Alfredo · Bernardi Luca
+4 more
The catalytic properties of chitosan aerogel for the direct asymmetric aldol reaction in water assisted by various surfactants and acid co‐catalysts have been evaluated by employing a range of donor and acceptor systems. A beneficial effect on both the yields and enantioselectivities was observed, and the combination of surfactants and acid co‐catalysts has proven particularly useful in the case of heterocyclic ketone donors.
Journals
2013 EN
Doknic Daniela · Abramo Morena · Sutkeviciute Ieva
+8 more
Glycomimetic molecules can be used to antagonize the action of carbohydrate‐binding proteins (lectins) involved in biological processes of high relevance for human and plant disease. In this paper we describe the derivatization with appropriate linkers of a previously described glycomimetic containing an α‐fucosyl amide anchor that is known to act as antagonist of the dendritic cell lectin DC‐SIGN. Key steps of the functionalization were the stereoselective epoxidation of an intermediate β‐amino‐cyclohexene‐carboxylic acid derivative, followed by regioselective opening with 2‐chloroethanol. Introduction of the linker does not alter the DC‐SIGN binding properties of the molecule, as shown by Surface Plasmon Resonance and NMR studies. Whereas the fucose‐based anchor allows the mimic to interact efficiently with fucose‐binding lectins, the linker could also be exploited for the synthesis of glycodendrimers, as well as for the study of ligand interactions with commercially available lectins by array technology. In particular, a tetravalent fucosylated dendrimer was obtained that displayed a low‐micromolar range of activity against DC‐SIGN. Additionally, screening of the ligand against lectins with common fucose specificity in an array format allowed the lectin from the bacterium Ralstonia solanacearum (RSL) to be identified as a potential target protein and suggested that even simple glycomimetic structures can attain a significant amount of selectivity among lectins with analogous specificity.
Journals
2013 EN
González Pedro Blas · Chandanshive Jay Zumbar · Fochi Mariafrancesca
+7 more
The reactivity of the ynamide tert ‐butyl N ‐ethynyl‐ N ‐phenylcarbamate ( 1 ) in the 1,3‐dipolar cycloaddition (1,3‐DC) with C ‐carboxymethyl‐ N ‐phenylnitrilimine was investigated. This [3+2] cycloaddition affords the 5‐amino pyrazole as a single regioisomer. The obtained cycloadduct has been activated at the 4‐position of the pyrazole ring through bromination and subsequently coupled with a phenyl group under Pd catalysis. A detailed computational study has been performed to fully explain the complete regioselectivity observed.
Journals
2013 EN
Bicalho Maria Aparecida Camargos · Pimenta Fausto Aloísio · BastosRodrigues Luciana
+9 more
Objective Alzheimer's disease (AD) has a multifactorial etiology involving an interaction of genetic and environmental factors. The Apolipoprotein E ε4 (ApoE ε4) is the single most important genetic risk factor for sporadic AD. Our aim was to study the association between sociodemographic, clinical data and gene polymorphisms in patients with sporadic AD in a heterogeneous genomic Brazilian population with low educational levels. Methods We selected 169 sporadic AD patients and 97 controls older than 65 years and compared co‐variables between them: age, years of education, vascular risk factors, genomic ancestry, and functional polymorphisms of ApoE , BDNF , COMT , and 5‐HTTLPR . We also determined the genomic ancestry of all individuals. Results The average years of education was significantly smaller in the patient's group ( p = 0.003), and they had a history of depression when compared with controls ( p < 0.001). The carriers of ApoE ε4 have an earlier onset of the disease (76.9 years) ( p = 0.001) than ApoE ε3 (79.5 years) ( p = 0.024). Patients with Met allele of Val66Met have a tendency to later onset of disease ( p = 0.056). There were no differences in the genomic ancestry between groups. Conclusion Low level of education and history of depression were associated with AD. Public policies and intensive observation of old‐age patients with lifetime history of depression, especially APOE ε4 carriers, could improve the well‐being of our population. Copyright © 2012 John Wiley & Sons, Ltd.
Journals
2013 EN
Takata Akemi · Otsuka Motoyuki · Yoshikawa Takeshi
+10 more
MicroRNAs (miRNAs) are small RNAs that regulate the expression of specific target genes. While deregulated miRNA expression levels have been detected in many tumors, whether miRNA functional impairment is also involved in carcinogenesis remains unknown. We investigated whether deregulation of miRNA machinery components and subsequent functional impairment of miRNAs are involved in hepatocarcinogenesis. Among miRNA‐containing ribonucleoprotein complex components, reduced expression of DDX20 was frequently observed in human hepatocellular carcinomas, in which enhanced nuclear factor‐κB (NF‐κB) activity is believed to be closely linked to carcinogenesis. Because DDX20 normally suppresses NF‐κB activity by preferentially regulating the function of the NF‐κB‐suppressing miRNA‐140, we hypothesized that impairment of miRNA‐140 function may be involved in hepatocarcinogenesis. DNA methyltransferase 1 (Dnmt1) was identified as a direct target of miRNA‐140, and increased Dnmt1 expression in DDX20‐deficient cells hypermethylated the promoters of metallothionein genes, resulting in decreased metallothionein expression leading to enhanced NF‐κB activity. MiRNA‐140‐knockout mice were prone to hepatocarcinogenesis and had a phenotype similar to that of DDX20 deficiency, suggesting that miRNA‐140 plays a central role in DDX20 deficiency‐related pathogenesis. Conclusion : These results indicate that miRNA‐140 acts as a liver tumor suppressor, and that impairment of miRNA‐140 function due to a deficiency of DDX20, a miRNA machinery component, could lead to hepatocarcinogenesis. (H EPATOLOGY 2013)
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Journals
2013 EN
GarciaMartinez Rita · Caraceni Paolo · Bernardi Mauro
+3 more
Since the introduction of human serum albumin as a plasma expander in the 1940s, considerable research has allowed a better understanding of its biochemical properties and potential clinical benefits. Albumin has a complex structure, which is responsible for a variety of biological functions. In disease, the albumin molecule is susceptible to modifications that may alter its biological activity. During the last decades, different methods to measure albumin function have been developed. Recent studies have shown that not only albumin concentration but also albumin function is reduced in liver failure. This observation led to the concept of effective albumin concentration , which represents the fact that plasma albumin concentration does not reflect its function. Indeed, in liver disease albumin function is several times less than its concentration. In patients with cirrhosis, albumin infusion reduces mortality in patients with spontaneous bacterial peritonitis and improves outcome following large volume paracentesis. In combination with vasoconstrictors, albumin is useful in the management of patients with hepatorenal syndrome. Its role is being investigated in a large number of indications, which rely on its volume and nonvolume expansion functions such as stroke, severe sepsis, Alzheimer's disease, malaria, burns, and ovarian hyperstimulation syndrome. This review explores the above concepts, reviews the available evidence for the use of albumin in liver diseases, defines therapeutic limitations, and explores the challenges that should be addressed in future research. (H epatology 2013;58:1836–1846)
Lippincott Williams & Wilkins
Journals
2013 EN
Cosset Érika · Petty Tom J. · Dutoit Valérie
+14 more
Glioblastoma is a deadly malignant brain tumor and one of the most incurable forms of cancer in need of new therapeutic targets. As some cancers are known to be caused by a virus, the discovery of viruses could open the possibility to treat, and perhaps prevent, such a disease. Although an association with viruses such as cytomegalovirus or Simian virus 40 has been strongly suggested, involvement of these and other viruses in the initiation and/or propagation of glioblastoma remains vague, controversial and warrants elucidation. To exhaustively address the association of virus and glioblastoma, we developed and validated a robust metagenomic approach to analyze patient biopsies via high‐throughput sequencing, a sensitive tool for virus screening. In addition to traditional clinical diagnostics, glioblastoma biopsies were deep‐sequenced and analyzed with a multistage computational pipeline to identify known or potentially discover unknown viruses. In contrast to the studies reporting the presence of viral signatures in glioblastoma, no common or recurring active viruses were detected, despite finding an antiviral‐like type I interferon response in some specimens. Our findings highlight a discrete and non‐specific viral signature and uncharacterized short RNA sequences in glioblastoma. This study provides new insights into glioblastoma pathogenesis and defines a general methodology that can be used for high‐resolution virus screening and discovery in human cancers.
Journals
2013 EN
Pellegrini Camilla · Zulian Alessandra · Gualandi Francesca
+9 more
Dystrophin is a subsarcolemmal protein that, by linking the actin cytoskeleton to the extracellular matrix via dystroglycans, is critical for the integrity of muscle fibers. Here, we report that epidermal melanocytes, obtained from conventional skin biopsy, express dystrophin with a restricted localization to the plasma membrane facing the dermal–epidermal junction. In addition the full‐length muscle isoform mDp427 was clearly detectable in melanocyte cultures as assessed by immunohistochemistry, RNA, and Western blot analysis. Melanocytes of Duchenne muscular dystrophy (DMD) patients did not express dystrophin, and the ultrastructural analysis revealed typical mitochondrial alterations similar to those occurring in myoblasts from the same patients. Mitochondria of melanocytes from DMD patients readily accumulated tetramethylrhodamine methyl ester, indicating that they are energized irrespective of the presence of dystrophin but, at variance from mitochondria of control donors, depolarized upon the addition of oligomycin, suggesting that they are affected by a latent dysfunction unmasked by inhibition of the ATP synthase. Pure melanocyte cultures can be readily obtained by conventional skin biopsies and may be a feasible and reliable tool alternative to muscle biopsy for functional studies in dystrophinopathies. The mitochondrial dysfunction occurring in DMD melanocytes could represent a promising cellular biomarker for monitoring dystrophinopathies also in response to pharmacological treatments. J. Cell. Physiol. 228: 1323–1331, 2013. © 2012 Wiley Periodicals, Inc.
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Journals
2013 EN
Pummer Bernhard G. · Bauer Heidi · Bernardi Johannes
+5 more
Pollen grains are covered with lots of different biochemical compounds, like proteins, saccharides and lipids, which are only loosely attached to the pollen. Therefore, they can be separated from the pollen by suspending them in water. Since these compounds play a key role in many atmospheric processes (e.g. cloud condensation nucleation, ice nucleation, aerial allergen exposure), their separation and analyzing are of interest. The chemical composition of whole pollen grains is compared by both Raman and infrared spectroscopy with material that could be extracted from pollen with water. The dominant signals in the pollen grain Raman spectra are those from sporopollenin and carotenoids. These bands decrease in the washing water spectra, since sporopollenin is high molecular and thus is not extractable. The released material shows in turn a chemical composition that differs significantly between species, what is quite expected, since they differ even in the optical properties of their aqueous suspensions. The FTIR spectra show some additional bands to appear in comparison to the Raman spectra. Furthermore, we investigated the pollen rupturing and material release in the aqueous suspensions by drying them up and picturing the residues with a scanning electron microscope. We saw that corn pollen ejected loads of micrometer‐sized organelles, which are most likely starch granules. The more the pollen disrupted, the more the measured samples were covered with an amorphous film, which consists of the extracted pollen material, like lipids, sugars, and proteins – the same substances we detected by spectroscopy. Copyright © 2013 John Wiley & Sons, Ltd.