Phylogeny of the arachnid order Opiliones (Arthropoda) inferred from a combined approach of complete 18S and partial 28S ribosomal DNA sequences and morphology

The phylogenetic relationships among the main evolutionary lines of the arachnid order Opiliones were investigated by means of molecular (complete 18S rDNA and the D3 region of the 28S rDNA genes) and morphological data sets. Equally and differentially weighted parsimony analyses of independent and combined data sets provide evidence for the monophyly of the Opiliones. In all the analyses, the internal relationships of the group coincide in the monophyly of the following main groups: Cyphophthalmi, Eupnoi Palpatores, Dyspnoi Palpatores, and Laniatores. The Cyphophthalmi are monophyletic and sister to a clade that includes all the remaining opilionid taxa (=Phalangida). Within the Phalangida the most supported hypothesis suggests that Palpatores are paraphyletic, as follows: (Eupnoi (Dyspnoi + Laniatores)), but the alternative hypothesis (Laniatores (Eupnoi + Dyspnoi)) is more parsimonious in some molecular data analyses. Relationships within the four main clades are also addressed. Evolution of some morphological characters is discussed, and plesiomorphic states of these characters are evaluated using molecular data outgroup polarization. Finally, Martens' hypothesis of opilionid evolution is assessed in relation to our results.     

2- and 8-alkynyl-9-ethyladenines: Synthesis and biological activity at human and rat adenosine receptors

The synthesis of a series of 9-ethyladenine derivatives bearing alkynyl chains in 2- or 8-position was undertaken, based on the observation that replacement of the sugar moiety in adenosine derivatives with alkyl groups led to adenosine receptor antagonists. All the synthesized compounds were tested for their affinity at human and rat A₁, A_2A, and A₃ adenosine receptors in binding assays; the activity at the human A_2B receptor was determined in adenylyl cyclase experiments. Biological data showed that the 2-alkynyl derivatives possess good affinity and are slightly selective for the human A_2A receptor. The same compounds tested on the rat A₁ and A_2A subtypes showed in general lower affinity for both receptors. On the other hand, the affinity of the 8-alkynyl derivatives at the human A₁, A_2A, and A_2B receptors proved to be lower than that of the corresponding 2-alkynyl derivatives. On the contrary, the affinity of the same compounds for the human A₃ receptor was improved, resulting in A₃ selectivity. As in the case of the 2-alkynyl-substituted compounds, the 8-alkynyl derivatives showed decreased affinity for rat receptors. However, it is worthwhile to note that the 8-phenylethynyl-9-ethyladenine was the most active compound of the two series (K_i in the nanomolar range) at both the human and rat A₃ subtype. Docking experiments of the 2- and 8-phenylethynyl-9-ethyladenines, at a rhodopsin-based homology model, gave a rational explanation of the preference of the human A₃ receptor for the 8-substituted compound.     

Fragmentation of contaminant and endogenous DNA in ancient samples determined by shotgun sequencing; prospects for human palaeogenomics

BACKGROUND: Despite the successful retrieval of genomes from past remains, the prospects for human palaeogenomics remain unclear because of the difficulty of distinguishing contaminant from endogenous DNA sequences. Previous sequence data generated on high-throughput sequencing platforms indicate that fragmentation of ancient DNA sequences is a characteristic trait primarily arising due to depurination processes that create abasic sites leading to DNA breaks. METHODOLOGY/PRINCIPALS FINDINGS: To investigate whether this pattern is present in ancient remains from a temperate environment, we have 454-FLX pyrosequenced different samples dated between 5,500 and 49,000 years ago: a bone from an extinct goat (Myotragus balearicus) that was treated with a depurinating agent (bleach), an Iberian lynx bone not subjected to any treatment, a human Neolithic sample from Barcelona (Spain), and a Neandertal sample from the El Sidrón site (Asturias, Spain). The efficiency of retrieval of endogenous sequences is below 1% in all cases. We have used the non-human samples to identify human sequences (0.35 and 1.4%, respectively), that we positively know are contaminants. CONCLUSIONS: We observed that bleach treatment appears to create a depurination-associated fragmentation pattern in resulting contaminant sequences that is indistinguishable from previously described endogenous sequences. Furthermore, the nucleotide composition pattern observed in 5' and 3' ends of contaminant sequences is much more complex than the flat pattern previously described in some Neandertal contaminants. Although much research on samples with known contaminant histories is needed, our results suggest that endogenous and contaminant sequences cannot be distinguished by the fragmentation pattern alone.     

Conscious Brain-to-Brain Communication in Humans Using Non-Invasive Technologies

Human sensory and motor systems provide the natural means for the exchange of information between individuals, and, hence, the basis for human civilization. The recent development of brain-computer interfaces (BCI) has provided an important element for the creation of brain-to-brain communication systems, and precise brain stimulation techniques are now available for the realization of non-invasive computer-brain interfaces (CBI). These technologies, BCI and CBI, can be combined to realize the vision of non-invasive, computer-mediated brain-to-brain (B2B) communication between subjects (hyperinteraction). Here we demonstrate the conscious transmission of information between human brains through the intact scalp and without intervention of motor or peripheral sensory systems. Pseudo-random binary streams encoding words were transmitted between the minds of emitter and receiver subjects separated by great distances, representing the realization of the first human brain-to-brain interface. In a series of experiments, we established internet-mediated B2B communication by combining a BCI based on voluntary motor imagery-controlled electroencephalographic (EEG) changes with a CBI inducing the conscious perception of phosphenes (light flashes) through neuronavigated, robotized transcranial magnetic stimulation (TMS), with special care taken to block sensory (tactile, visual or auditory) cues. Our results provide a critical proof-of-principle demonstration for the development of conscious B2B communication technologies. More fully developed, related implementations will open new research venues in cognitive, social and clinical neuroscience and the scientific study of consciousness. We envision that hyperinteraction technologies will eventually have a profound impact on the social structure of our civilization and raise important ethical issues.     

Spatial mapping of phosphorus influx in bean root systems using digital autoradiography

A novel technique was developed to spatially map the phosphorus net influx capacity in intact root systems. The method is based on digital autoradiography and permits the quantification of phosphorus influx at high spatial resolution (2 mm). Roots of 18-d-old common bean plants were exposed to (32)P-labelled orthophosphate, quickly frozen, excised, lyophilized, scanned, and exposed to a storage phosphor screen. Plots of (32)P content versus root length (distance from the root tip or from the base of the root) were obtained for three different root classes: basal, basal laterals, and taproot laterals. Radioactivity detected by filmless autoradiography correlated well (r(2)=0.99) with measurements made by scintillation counting. Basal roots absorbed 2.5 times and 1.9 times more phosphorus than the taproot lateral and basal lateral root classes, respectively, in the first 20 mm from the root apex. External phosphorus markedly affected influx: roots averaged 5, 16, and 34 pmol P min(-1) in the apical 20 mm when exposed to 1, 5, and 10 microM P solutions, respectively. The spatial pattern of phosphorus influx along the root axes of the different root classes was rather homogeneous when measured on a root surface area basis. Phosphorus influx in the older segments of basal roots (those next to the hypocotyl) did not differ from the newer segments close to the root apex. However, a heterogeneous pattern was detected for basal roots when measured on a length basis, indicating that both root class and diameter constitute main factors controlling the spatial pattern of net influx.     

Palmitoylethanolamide Treatment Reduces Blood Pressure in Spontaneously Hypertensive Rats: Involvement of Cytochrome P450-Derived Eicosanoids and Renin Angiotensin System

Palmitoylethanolamide (PEA), a peroxisome proliferator-activated receptor-α agonist, has been demonstrated to reduce blood pressure and kidney damage secondary to hypertension in spontaneously hypertensive rat (SHR). Currently, no information is available concerning the putative effect of PEA on modulating vascular tone. Here, we investigate the mechanisms underpinning PEA blood pressure lowering effect, exploring the contribution of epoxyeicosatrienoic acids, CYP-dependent arachidonic acid metabolites, as endothelium-derived hyperpolarizing factors (EDHF), and renin angiotensin system (RAS) modulation. To achieve this aim SHR and Wistar-Kyoto rats were treated with PEA (30 mg/kg/day) for five weeks. Functional evaluations on mesenteric bed were performed to analyze EDHF-mediated vasodilation. Moreover, mesenteric bed and carotid were harvested to measure CYP2C23 and CYP2J2, the key isoenzymes in the formation of epoxyeicosatrienoic acids, and the soluble epoxide hydrolase, which is responsible for their degradation in the corresponding diols. Effect of PEA on RAS modulation was investigated by analyzing angiotensin converting enzyme and angiotensin receptor 1 expression. Here, we showed that EDHF-mediated dilation in response to acetylcholine was increased in mesenteric beds of PEA-treated SHR. Western blot analysis revealed that the increase in CYP2C23 and CYP2J2 observed in SHR was significantly attenuated in mesenteric beds of PEA-treated SHR, but unchanged in the carotids. Interestingly, in both vascular tissues, PEA significantly decreased the soluble epoxide hydrolase protein level, accompanied by a reduced serum concentration of its metabolite 14-15 dihydroxyeicosatrienoic acid, implying a reduction in epoxyeicosatrienoic acid hydrolisis. Moreover, PEA treatment down-regulated angiotensin receptor 1 and angiotensin converting enzyme expression, indicating a reduction in angiotensin II-mediated effects. Consistently, a damping of the activation of angiotensin receptor 1 underlying pathways in mesenteric beds was shown in basal conditions in PEA-treated SHR. In conclusion, our data demonstrate the involvement of epoxyeicosatrienoic acids and renin angiotensin system in the blood pressure lowering effect of PEA.     

Association of Genetic Variation in Adaptor Protein APPL1/APPL2 Loci with Non-Alcoholic Fatty Liver Disease

The importance of genetics and epigenetic changes in the pathogenesis of non alcoholic fatty liver disease (NAFLD) has been increasingly recognized. Adiponectin has a central role in regulating glucose and lipid metabolism and controlling inflammation in insulin-sensitive tissues and low adiponectin levels have been linked to NAFLD. APPL1 and APPL2 are adaptor proteins that interact with the intracellular region of adiponectin receptors and mediate adiponectin signaling and its effects on metabolism. The aim of our study was the evaluation of a potential association between variants at APPL1 and APPL2 loci and NAFLD occurrence. The impact on liver damage and hepatic steatosis severity has been also evaluated. To this aim allele frequency and genotype distribution of APPL1- rs3806622 and -rs4640525 and APPL2-rs 11112412 variants were evaluated in 223 subjects with clinical diagnosis of NAFLD and compared with 231 healthy subjects. The impact of APPL1 and APPL2 SNPs on liver damage and hepatic steatosis severity has been also evaluated. The minor-allele combination APPL1-C/APPL2-A was associated with an increased risk of NAFLD (OR = 2.50 95% CI 1.45–4.32; p<0.001) even after adjustment for age, sex, body mass index, insulin resistance (HOMA-IR), triglycerides and adiponectin levels. This allele combination carrier had higher plasma alanine aminotransferase levels (Diff = 15.08 [7.60–22.57] p = 0.001) and an increased frequency of severe steatosis compared to the reference allele combination (OR = 3.88; 95% CI 1.582–9.531; p<0.001). In conclusion, C-APPL1/A-APPL2 allele combination is associated with NAFLD occurrence, with a more severe hepatic steatosis grade and with a reduced adiponectin cytoprotective effect on liver.     

Molecular ecology of nifH genes and transcripts in the eastern Mediterranean Sea

The eastern Mediterranean Sea is one of the most extreme oligotrophic oceanic regions on earth in terms of nutrient concentrations and primary productivity. Nitrogen fixation has been suggested to contribute to the high N : P molar ratios of approximately 28:1 found in this region. Surprisingly, no molecular biological work has been performed in situ to assess whether N(2) fixation genes actually occur in the eastern Mediterranean Sea, or to determine which organisms are responsible for this process. In this study, we examined the presence and expression of nitrogenase genes (nifH) in the upper water layer of the eastern Mediterranean. Clone libraries constructed from both DNA and reverse-transcribed PCR-amplified mRNA were examined and compared. We observed different nifH genes from diverse microbial groups, such as Cyanobacteria, Proteobacteria and methanogenic Archaea. Interestingly, numerous phylotypes were observed in coastal stations at the DNA level but none were active. However, in far offshore stations, the phylotypes observed at the DNA level were the ones that were actually active. Our preliminary study revealed diverse diazotrophs that possess and express nifH genes, which may support N(2) fixation in the eastern Mediterranean Sea.     

Concentrative uptake of cyclic ADP-ribose generated by BST-1+ stroma stimulates proliferation of human hematopoietic progenitors

Cyclic ADP-ribose (cADPR) is an intracellular calcium mobilizer generated from NAD(+) by the ADP-ribosyl cyclases CD38 and BST-1. cADPR, both exogenously added and paracrinally produced by a CD38(+) feeder layer, has recently been demonstrated to stimulate the in vitro proliferation of human hemopoietic progenitors (HP) and also the in vivo expansion of hemopoietic stem cells. The low density of BST-1 expression on bone marrow (BM) stromal cells and the low specific activity of the enzyme made it unclear whether cADPR generation by a BST-1(+) stroma could stimulate HP proliferation in the BM microenvironment. We developed and characterized two BST-1(+) stromal cell lines, expressing an ectocellular cyclase activity similar to that of BST-1(+) human mesenchymal stem cells, the precursors of BM stromal cells. Long term co-culture of cord blood-derived HP over these BST-1(+) feeders determined their expansion. Influx of paracrinally generated cADPR into clonogenic HP was mediated by a concentrative, nitrobenzylthioinosine- and dipyridamole-inhibitable nucleoside transporter, this providing a possible explanation to the effectiveness of the hormone-like concentrations of the cyclic nucleotide measured in the medium conditioned by BST-1(+) feeders. These results suggest that the BST-1-catalyzed generation of extracellular cADPR, followed by the concentrative uptake of the cyclic nucleotide by HP, may be physiologically relevant in normal hemopoiesis.