Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways.

Systematic evaluation of matrix effects in hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry.

Reversed phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) is the gold standard technique in bioanalysis. However, hydrophilic interaction chromatography (HILIC) could represent a viable alternative to RPLC for the analysis of polar and/or ionizable compounds, as it often provides higher MS sensitivity and alternative selectivity. Nevertheless, this technique can be also prone to matrix effects (ME). ME are one of the major issues in quantitative LC-MS bioanalysis. To ensure acceptable method performance (i.e., trueness and precision), a careful evaluation and minimization of ME is required. In the present study, the incidence of ME in HILIC-MS/MS and RPLC-MS/MS was compared for plasma and urine samples using two representative sets of 38 pharmaceutical compounds and 40 doping agents, respectively. The optimal generic chromatographic conditions in terms of selectivity with respect to interfering compounds were established in both chromatographic modes by testing three different stationary phases in each mode with different mobile phase pH. A second step involved the assessment of ME in RPLC and HILIC under the best generic conditions, using the post-extraction addition method. Biological samples were prepared using two different sample pre-treatments, i.e., a non-selective sample clean-up procedure (protein precipitation and simple dilution for plasma and urine samples, respectively) and a selective sample preparation, i.e., solid phase extraction for both matrices. The non-selective pretreatments led to significantly less ME in RPLC vs. HILIC conditions regardless of the matrix. On the contrary, HILIC appeared as a valuable alternative to RPLC for plasma and urine samples treated by a selective sample preparation. Indeed, in the case of selective sample preparation, the compounds influenced by ME were different in HILIC and RPLC, and lower and similar ME occurrence was generally observed in RPLC vs. HILIC for urine and plasma samples, respectively. The complementary of both chromatographic modes was also demonstrated, as ME was observed only scarcely for urine and plasma samples when selecting the most appropriate chromatographic mode.

Biological Characterization of Gene Response to Insulin-Induced Hypoglycemia in Mouse Retina.

Glucose is the most important metabolic substrate of the retina and maintenance of normoglycemia is an essential challenge for diabetic patients. Chronic, exaggerated, glycemic excursions could lead to cardiovascular diseases, nephropathy, neuropathy and retinopathy. We recently showed that hypoglycemia induced retinal cell death in mouse via caspase 3 activation and glutathione (GSH) decrease. Ex vivo experiments in 661W photoreceptor cells confirmed the low-glucose induction of death via superoxide production and activation of caspase 3, which was concomitant with a decrease of GSH content. We evaluate herein retinal gene expression 4 h and 48 h after insulin-induced hypoglycemia. Microarray analysis demonstrated clusters of genes whose expression was modified by hypoglycemia and we discuss the potential implication of those genes in retinal cell death. In addition, we identify by gene set enrichment analysis, three important pathways, including lysosomal function, GSH metabolism and apoptotic pathways. Then we tested the effect of recurrent hypoglycemia (three successive 4h periods of hypoglycemia spaced by 48 h recovery) on retinal cell death. Interestingly, exposure to multiple hypoglycemic events prevented GSH decrease and retinal cell death, or adapted the retina to external stress by restoring GSH level comparable to control situation. We hypothesize that scavenger GSH is a key compound in this apoptotic process, and maintaining "normal" GSH level, as well as a strict glycemic control, represents a therapeutic challenge in order to avoid side effects of diabetes, especially diabetic retinopathy.

Dominant-Negative Effects of Adult-Onset Huntingtin Mutations Alter the Division of Human Embryonic Stem Cells-Derived Neural Cells.

Mutations of the huntingtin protein (HTT) gene underlie both adult-onset and juvenile forms of Huntington's disease (HD). HTT modulates mitotic spindle orientation and cell fate in mouse cortical progenitors from the ventricular zone. Using human embryonic stem cells (hESC) characterized as carrying mutations associated with adult-onset disease during pre-implantation genetic diagnosis, we investigated the influence of human HTT and of an adult-onset HD mutation on mitotic spindle orientation in human neural stem cells (NSCs) derived from hESCs. The RNAi-mediated silencing of both HTT alleles in neural stem cells derived from hESCs disrupted spindle orientation and led to the mislocalization of dynein, the p150Glued subunit of dynactin and the large nuclear mitotic apparatus (NuMA) protein. We also investigated the effect of the adult-onset HD mutation on the role of HTT during spindle orientation in NSCs derived from HD-hESCs. By combining SNP-targeting allele-specific silencing and gain-of-function approaches, we showed that a 46-glutamine expansion in human HTT was sufficient for a dominant-negative effect on spindle orientation and changes in the distribution within the spindle pole and the cell cortex of dynein, p150Glued and NuMA in neural cells. Thus, neural derivatives of disease-specific human pluripotent stem cells constitute a relevant biological resource for exploring the impact of adult-onset HD mutations of the HTT gene on the division of neural progenitors, with potential applications in HD drug discovery targeting HTT-dynein-p150Glued complex interactions.

Immediate ecotoxicological effects of short-lived oil spills on marine biota.

Marine environments are frequently exposed to oil spills as a result of transportation, oil drilling or fuel usage. Whereas large oil spills and their effects have been widely documented, more common and recurrent small spills typically escape attention. To fill this important gap in the assessment of oil-spill effects, we performed two independent supervised full sea releases of 5 m(3) of crude oil, complemented by on-board mesocosm studies and sampling of accidentally encountered slicks. Using rapid on-board biological assays, we detect high bioavailability and toxicity of dissolved and dispersed oil within 24 h after the spills, occurring fairly deep (8 m) below the slicks. Selective decline of marine plankton is observed, equally relevant for early stages of larger spills. Our results demonstrate that, contrary to common thinking, even small spills have immediate adverse biological effects and their recurrent nature is likely to affect marine ecosystem functioning.

Erratum: Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6–4-fold following a before–after control–impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2–77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9–48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure

Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6–4-fold following a before–after control–impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2–77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9–48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure

Experimental assessment of the effects of a Neotropical nocturnal piscivore on juvenile native and invasive fishes

We experimentally examined the predator-prey relationships between juvenile spotted sorubim Pseudoplastystoma corruscans and young-of-the-year invasive and native fish species of the Paraná River basin, Brazil. Three invasive (peacock bass Cichla piquiti, Nile tilapia Oreochromis niloticus, and channel catfish Ictalurus punctatus) and two native (yellowtail tetra Astyanax altiparanae and streaked prochilod Prochilodus lineatus) fish species were offered as prey to P. corruscans in 300 L aquaria with three habitat complexity treatments (0%, 50% and 100% structure-covered). Prey survival was variable through time and among species (C. piquiti < O. niloticus < A. altiparanae < P. lineatus < I. punctatus), depending largely on species-specific prey behavior but also on prey size and morphological defenses. Habitat complexity did not directly affect P. corruscans piscivory but some prey species changed their microhabitat use and shoaling behavior among habitat treatments in predator’s presence. Pseudoplatystoma corruscans preyed preferentially on smaller individuals of those invasive species with weak morphological defensive features that persisted in a non-shoaling behavior. Overall, our results contrast with those in a companion experiment using a diurnal predator, suggesting that nocturnal piscivores preferentially prey on different (rather diurnal) fish species and are less affected by habitat complexity. Our findings suggest that recovering the native populations of P. corruscans might help controling some fish species introduced to the Paraná River basin, particularly C. piquiti and O. niloticus, whose parental care is expected to be weak or null at night

Hydrology, light and the use of organic and inorganic materials as structuring factors of biological communities in Mediterranean streams

Hydrological disturbances, light availability and nutrients are the most relevant factors determining the structure of the biological communities in Mediterranean rivers. While some hydrological disturbances are able to induce catastrophic effects, which may cause a complete reset in physical and biological conditions, continued enrichment or changes in light availability are factors leading to the progressive shift in the communities of autotrophs and heterotrophs in the systems. Primary production in Mediterranean streams shows relevant seasonal changes which mainly follows the variations in light availability. In most forested streams, the algal community is shade-adapted. Nutrient enrichment (especially phosphorus) leads to marked increases in primary production, but this increase is not lineal and there is a saturation of algal biomass even in the most enriched systems. The heterotrophs (bacteria, fungi) are related to the pattern of DOC availability (which most depends on the seasonal discharge and leaf fall dynamics) and to the available substrata in the stream. It has been repeatedly observed that shorttime increases of extracellular enzyme activities are related to the accumulation of autochthonous (algal) and/or allochthonous (leaves) organic matter on the streambed during spring and summer, this being more remarkable in dry than in wetter years. Flow reduction favours detritus concentration in pools, and the subsequent increase in the density and biomass of the macroinvertebrate community. In Mediterranean streams collectors are accounting for the highest density and biomass, this being more remarkable in the least permanent systems, in accordance with the effect of floods on the organic matter availability. Nutrients, through the effect on the primary producers, also affect the trophic food web in the streams by favouring the predominance of grazers

Effects of artisanal fisheries on the scorpaenids (Scorpaena spp.) reproduction in the marine protected area of Cap de Creus (NW Mediterranean)

Rockfish species are considered important to the ecology of rocky-reef communities which constitute a key habitat in many coastal marine protected areas (MPAs). These species, which are commercially valuable for artisanal fisheries in the Mediterranean, display particular biological traits that could render them vulnerable to fishing. In this study we monitored the artisanal fisheries of scorpaenids (Scorpaena spp.) in the MPA of Cap de Creus (northwestern Mediterranean) in order to estimate the status of their populations, to link captures with the reproduction of these species, and to evaluate the potential impact that artisanal fishing may have on them. Data from onboard sampling with artisanal fishermen and from fisheries statistics (total landings) were used. Total landings and catch per unit of effort (CPUE) follow a clearly seasonal cycle, with a prominent peak during the summer months coinciding with their spawning season, which may be due to mating behavior prior to fertilization. Although maximum sizes are bigger inside the MPA than in non-protected areas situated close by, a significant percentage of individuals caught inside the MPA are below their size at sexual maturity. Although rockfish seem to be favored by the partial protection of the MPA, the allowed artisanal fisheries are probably impacting the reproduction of these species

Computer-aided discovery of biological activity spectra for anti-aging and anti-cancer olive oil oleuropeins

Aging is associated with common conditions, including cancer, diabetes, cardiovascular disease, and Alzheimer"s disease. The type of multi‐targeted pharmacological approach necessary to address a complex multifaceted disease such as aging might take advantage of pleiotropic natural polyphenols affecting a wide variety of biological processes. We have recently postulated that the secoiridoids oleuropein aglycone (OA) and decarboxymethyl oleuropein aglycone (DOA), two complex polyphenols present in health‐promoting extra virgin olive oil (EVOO), might constitute a new family of plant‐produced gerosuppressant agents. This paper describes an analysis of the biological activity spectra (BAS) of OA and DOA using PASS (Prediction of Activity Spectra for Substances) software. PASS can predict thousands of biological activities, as the BAS of a compound is an intrinsic property that is largely dependent on the compound"s structure and reflects pharmacological effects, physiological and biochemical mechanisms of action, and specific toxicities. Using Pharmaexpert, a tool that analyzes the PASS‐predicted BAS of substances based on thousands of"mechanism‐ effect" and"effect‐mechanism" relationships, we illuminate hypothesis‐generating pharmacological effects, mechanisms of action, and targets that might underlie the anti‐aging/anti‐cancer activities of the gerosuppressant EVOO oleuropeins.

Effects of Surface Properties and Wood Modification into Direct Printing on Wood

Building industry is a high volume branch which could provide prominent markets for wood based interior decoration solutions. Competition in interior decoration markets requires versatility in appearance. Versatility in wood appearance and added value could be achieved by printing grain patterns of different species or images directly onto wood. The problem when planning wood printing’s implementing into durable applications is basically how to transfer a high quality image or print sustainably onto wood, which is porous, heterogeneous, dimensionally unstable, non-white and rough. Wood preservation or treating, and modification can provide durability against degradation but also effect to the surface properties of wood which will effect on printability. Optimal adhesion is essential into print quality, as too high ink absorbance can cause spreading and too low ink absorbance cause pale prints. Different printing techniques have different requirements on materials and production. The direct printing on wood means, that intermedias are not used. Printing techniques with flexible printing plates or in fact non-impact techniques provide the best basis for wood printing. Inkjet printing of wood with different mechanical or chemical surface treatments, and wood plastic composite material gave good results that encourage further studies of the subject. Sanding the wood surface anti-parallel to the grain gave the best overall printing quality. Spreading parallel to the grain could not be avoided totally, except in cases where wood was treated hydrophobic so adhesion of the ink was not sufficient. Grain pattern of the underlying wood stays clearly visible in the printed images. Further studies should be made to fine tune the methods that already gave good results. Also effects of moisture content of wood, different inks, and long-term exposure to UV-radiation should be tested.

Chemical constituents of methanolic extracts of Jatropha curcas L and effects on Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

The biological activity of seven extracts from leaves of different Jatropha curcas L (Euphorbiaceae) accessions was evaluated on Spodoptera frugiperda. Methanol extracts were incorporated into an artificial diet and offered to the larval stage of S. frugiperda. The parameters evaluated were length of larval and pupal stages, mortality of larval and total cycle stage, and weight of pupae. The extracts of the EMB accessions showed the best result for larval mortality at 60.00 and 56.67%, compared with the control, respectively. Hexane partition of the methanol extract of the leaves of PM-14 accessions allowed the identification of phytosterols, phytol and n-alkanols.

Synthesis, characterization, and biological activity of a new class of dialkylphosphorylhydrazone derivatives of isatin

Sixteen dialkylphosphorylhydrazones were synthesized by condensation of phosphorylhydrazines with substituted isatins. Products were characterized by FTIR, ¹H-NMR, 13C-NMR, and 31P-NMR. Fungicidal activities of these compounds against Rhizoctonia solani and Fusarium oxysporum were also evaluated. Some compounds inhibited the growth of Rhizoctonia solani and Fusarium oxysporum by 43% and 51%, respectively. These compounds exhibited no effects on germination of lettuce seeds (Lactuca sativa L).

Biheterocyclic ligands: synthesis, characterization and coordinating properties of bis(4-amino-5-mercapto-1,2,4-triazol-3-yl) alkanes with transition metal ions and their thermokinetic and biological studies

The Co(II), Ni(II) and Cu(II) metal ions complexes of Bis(4-amino-5-mercapto-1,2,4-triazol-3-yl) alkanes (BATs) have been prepared and characterized by elemental analysis, conductivity measurements infrared, magnetic susceptibility, the electronic spectral data and thermal studies. Based on spectral and magnetic results, the ligands are tetradentate coordinating through the N and S-atoms of BATs; six-coordinated octahedral or distorted octahedral and some times four-coordinated square planar were proposed for these complexes. Activation energies computed for the thermal decomposition steps were compared. The ligands and their metal complexes were tested in vitro for their biological effects. Their activities against two gram-positive, two gram-negative bacteria and two fungal species were found to vary from moderate to very strong.