Interactions Between Chronic Stress and Chronic Consumption of Caffeine on the Enzymatic Antioxidant System

We studied the effect of chronic caffeine on parameters related to oxidative stress in different brain regions of stressed and non-stressed rats. Wistar rats were divided into three groups: control (receiving water), caffeine 0.3 g/L and caffeine 1.0 g/L (in the drinking water). These groups were subdivided into non-stressed and stressed (repeated restraint stress during 40 days). Lipid peroxide levels and the total radical-trapping potential were assessed, as well as antioxidant enzyme activities superoxide dismutase, gluthatione peroxidase, and catalase in hippocampus, striatum and cerebral cortex. Results showed interactions between stress and caffeine, especially in the cerebral cortex, since caffeine increased the activity of some antioxidant enzymes, but not in stressed animals. We concluded that chronic administration of caffeine led, in some cases, to increased activity of antioxidant enzymes. However, these effects were not observed in the stressed animals.     

A common haplotype of <Emphasis Type="Italic">DRD3</Emphasis> affected by recent positive selection is associated with protection from schizophrenia

The number and frequency of susceptibility alleles at loci associated to most psychiatric disorders is largely unknown, in spite of its relevance for the design of studies aiming to find these alleles. Both, common polymorphisms and rare mutations may contribute to the genetic susceptibility to complex psychiatric disorders, being the relative relevance of each type of variation currently under debate. Here, we confirmed the existence of a common protective haplotype against schizophrenia at the dopamine D₃ receptor (DRD3) gene, by replication and pooled analysis with previous data (Mantel–Haenszel χ² P value = 0.00227; OR = 0.79, 95% CI 0.68–0.92, based on 794 cases and 1,078 controls from three independent populations of European origin). This protective haplotype is at very low frequency in Sub-Saharan Africans (median 0.06) and at intermediate frequencies in other populations (median 0.25). We also revealed, by examining the patterns of linkage disequilibrium around this gene, that the protective haplotype has reached high frequency in non-African populations due to selection acting, most probably, on a linked functional polymorphism, the non-synonymous single nucleotide polymorphism Ser9Gly (rs6280), also at DRD3. Thus, this finding shows that the natural selection may play a role in the existence of common alleles conferring different susceptibility to schizophrenia. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Changes in lipid class and fatty acid composition during development in white seabream (Diplodus sargus) eggs and larvae

To establish the changes which occur during embryogenesis and early larvae development, eggs, yolk-sac larvae (one day old larvae) and absorbed yolk-sac larvae (three day old larvae) of white sea bream were examined for lipid class and fatty acid composition. The development was characterized by a decrease in all lipid classes with the exception of phosphatidylserine (PS) and fatty free acids (FFA) which increased, and sphingomyelin (SM) which remained unchanged. The changes observed in lipid class content and the decrease in fatty acids in total lipid (TL) reflect the utilization and mobilization of lipids during both embryogenesis and early larvae development. Fluctuations in the relative composition of fatty acids in phosphatidylcholine (PC) during development suggest a selective bulk uptake and catabolism of fatty acids in this lipid class. Unlike PC, catabolism of triacylglycerol (TG) fatty acid appears to be non-selective. During development, the decrease in levels of polyunsaturated fatty acids (PUFA) eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic (22:6n-3, DHA) in total lipid denotes their utilization as energy substrate by Diplodus sargus larvae.     

Blood glucose responses in humans mirror lactate responses for individual anaerobic threshold and for lactate minimum in track tests

The equilibrium point between blood lactate production and removal (La-(min)) and the individual anaerobic threshold (IAT) protocols have been used to evaluate exercise. During progressive exercise, blood lactate [La-]b, catecholamine and cortisol concentrations, show exponential increases at upper anaerobic threshold intensities. Since these hormones enhance blood glucose concentrations [Glc]b, this study investigated the [Glc] and [La-]b responses during incremental tests and the possibility of considering the individual glucose threshold (IGT) and glucose minimum (Glc(min)) in addition to IAT and La-(min) in evaluating exercise. A group of 15 male endurance runners ran in four tests on the track 3000 m run (v3km); IAT and IGT - 8 x 800 m runs at velocities between 84% and 102% of v3km; La-(min) and Glc(min) - after lactic acidosis induced by a 500-m sprint, the subjects ran 6 x 800 m at intensities between 87% and 97% of v3km; endurance test (ET) - 30 min at the velocity of IAT. Capillary blood (25 microl) was collected for [La-]b and [Glc]b measurements. The IAT and IGT were determined by [La-]b and [Glc]b kinetics during the second test. The La-(min) and Glc(min) were determined considering the lowest [La-] and [Glc]b during the third test. No differences were observed (P < 0.05) and high correlations were obtained between the velocities at IAT [283 (SD 19) and IGT 281 (SD 21) m. x min(-1); r = 0.096; P < 0.001] and between La-(min) [285 (SD 21)] and Glc(min) [287 (SD 20) m. x min(-1) r = 0.77; P < 0.05]. During ET, the [La-]b reached 5.0 (SD 1.1) and 5.3 (SD 1.0) mmol x l(-1) at 20 and 30 min, respectively (P > 0.05). We concluded that for these subjects it was possible to evaluate the aerobic capacity by IGT and Glc(min) as well as by IAT and La-(min).     

Polychaete diversity in the Scotia Arc benthic realm: Are polychaetes tracers for faunal exchange?

The Scotia Arc is the only shallow-water and island bridge linking nowadays Patagonia and the Antarctic. The Antarctic Circumpolar Current as an oceanographic peculiarity makes this region an interesting biogeographic transition zone, because this frontal system traditionally is said to isolate the Antarctic fauna from that of the adjacent northern ecosystems. Based on benthos samples from three expeditions onboard R/V Polarstern, we studied distribution patterns of 200 polychaete species and 34 major benthic taxa in order to evaluate the role of polychaetes in the benthic realm of this part of the Southern Ocean. ANOSIM test distinguished three station groups: the central eastern Scotia Sea, the continental shelf off South America and stations at the tip of the Antarctic Peninsula. These station groups differed in organism densities and diversities with stations at the tip of the Antarctic Peninsula hosting the most diverse and dense community. The polychaete diversity patterns in the three assemblages evidenced closer connectivity between the tip of the Antarctic Peninsula and the central eastern Scotia Sea than between the continental shelf off South America with either the stations off the tip of the Peninsula or the central eastern Scotia Sea. This is probably supported by the Polar Front, which divides the island chain into two branches. Species distribution and community patterns of polychaetes appear to be associated with oceanographic and sediment conditions in this region. Most of the shared species showed the capability to tolerate differences in hydrostatic pressure. We suggest that the islands of the Scotia Sea may constitute a bridge for exchange of benthic species, particularly for polychaetes with eurybathic distribution and high dispersal capabilities.     

Simultaneous Saccharification and Fermentation of Hydrothermal Pretreated Lignocellulosic Biomass: Evaluation of Process Performance Under Multiple Stress Conditions

Industrial lignocellulosic bioethanol processes are exposed to different environmental stresses (such as inhibitor compounds, high temperature, and high solid loadings). In this study, a systematic approach was followed where the liquid and solid fractions were mixed to evaluate the influence of varied solid loadings, and different percentages of liquor were used as liquid fraction to determine inhibitor effect. Ethanol production by simultaneous saccharification and fermentation (SSF) of hydrothermally pretreated Eucalyptus globulus wood (EGW) was studied under combined diverse stress operating conditions (30–38 °C, 60–80 g of liquor from hydrothermal treatment or autohydrolysis (containing inhibitor compounds)/100 g of liquid and liquid to solid ratio between 4 and 6.4 g liquid in SSF/g unwashed pretreated EGW) using an industrial Saccharomyces cerevisiae strain supplemented with low-cost byproducts derived from agro-food industry. Evaluation of these variables revealed that the combination of temperature and higher solid loadings was the most significant variable affecting final ethanol concentration and cellulose to ethanol conversion, whereas solid and autohydrolysis liquor loadings had the most significant impact on ethanol productivity. After optimization, an ethanol concentration of 54 g/L (corresponding to 85 % of conversion and 0.51 g/Lh of productivity at 96 h) was obtained at 37 °C using 60 % of autohydrolysis liquor and 16 % solid loading (liquid to solid ratio of 6.4 g/g). The selection of a suitable strain along with nutritional supplementation enabled to produce noticeable ethanol titers in quite restrictive SSF operating conditions, which can reduce operating cost and boost the economic feasibility of lignocellulose-to-ethanol processes.     

Paracoccidioides brasiliensis antigen batches from the same isolate show immunological and biochemical differences

We investigated the occurrence of antigenic and biochemical variability among Paracoccidioides brasiliensis antigen batches prepared according to the same protocol. Initially (experiment #1), we analyzed two antigen lots of two human isolates (Bt1 & Bt2), cultured in two media (PYG: bactopeptone, yeast extract, glucose; MMM: McVeigh & Morton medium) in SDS-PAGE and in two immunological tests (imunodiffusion-ID and footpad swelling test-FPT). Afterwards (experiment #2), we compared the antigenic profile of three antigen batches from three human isolates (Bt1, Bt2 & Bt3) by two-dimensional immunoelectrophoresis (2 D-IEP) against a reference system for P. brasiliensis antigens. In experiment #1, there were important intra- and inter-strain antigenic differences between batches of the fungal isolates cultured on both media. The block titration of the antigen batches for the immunological tests revealed correlation between protein concentration and biological activity in ID and no correlation in FPT. In experiment #2, the reference system for P. brasiliensis showed 26 antigen peaks. There were important differences between batches prepared from the same isolate and between batches from different isolates. Our data suggested the occurrence of instability in the synthesis of antigenic components by a same P. brasiliensis isolate, under controlled incubation conditions.     

What Do Pneumocystis Organisms Tell Us about the Phylogeography of Their Hosts? The Case of the Woodmouse Apodemus sylvaticus in Continental Europe and Western Mediterranean Islands

Pneumocystis fungi represent a highly diversified biological group with numerous species, which display a strong host-specificity suggesting a long co-speciation process. In the present study, the presence and genetic diversity of Pneumocystis organisms was investigated in 203 lung samples from woodmice (Apodemus sylvaticus) collected on western continental Europe and Mediterranean islands. The presence of Pneumocystis DNA was assessed by nested PCR at both large and small mitochondrial subunit (mtLSU and mtSSU) rRNA loci. Direct sequencing of nested PCR products demonstrated a very high variability among woodmouse-derived Pneumocystis organisms with a total number of 30 distinct combined mtLSU and mtSSU sequence types. However, the genetic divergence among these sequence types was very low (up to 3.87%) and the presence of several Pneumocystis species within Apodemus sylvaticus was considered unlikely. The analysis of the genetic structure of woodmouse-derived Pneumocystis revealed two distinct groups. The first one comprised Pneumocystis from woodmice collected in continental Spain, France and Balearic islands. The second one included Pneumocystis from woodmice collected in continental Italy, Corsica and Sicily. These two genetic groups were in accordance with the two lineages currently described within the host species Apodemus sylvaticus. Pneumocystis organisms are emerging as powerful tools for phylogeographic studies in mammals.     

A re-evaluation of management units based on gene flow of a rare waterbird in the Americas

The maintenance of gene flow in species that have experienced population contractions and are geographically fragmented is important to the maintenance of genetic variation and evolutionary potential; thus, gene flow is also important to conservation and management of these species. For example, the Reddish Egret (Egretta rufescens) has recovered after severe population reductions during the 19th and 20th centuries, but population numbers remain below historical levels. In this study, we characterized gene flow among management units of the Reddish Egret by using ten nuclear microsatellite markers and part of the mitochondrial (mtDNA) control region from 176 nestlings captured at eight localities in Mexico (Baja California, Chiapas, Tamaulipas, and Yucatan), the USA (Texas, Louisiana, and Florida), and the Bahamas. We found evidence of population structure and that males disperse more often and across longer distances compared with females, which is congruent with previous banding and telemetry data. The maternally inherited mtDNA and biparentally inherited microsatellite data supported slightly different MU models; however, when interpreted together, a four MU model that considered population structure and geographic proximity was most optimal. Namely, MU 1 (Baja California); MU 2 (Chiapas); MU 3 (Yucatan, Tamaulipas, Texas, and Louisiana); and MU 4 (Florida and the Bahamas). Regions outside our sampled localities (e.g., the Greater Antilles and South America) require additional sampling to fully understand gene flow and movement of individuals across the species’ entire range. However, the four MUs we have defined group nesting localities into genetically similar subpopulations, which can guide future management plans.