Современные представления о НСV−инфекции

Рассмотрены достижения в изучении этиологии, патогенеза и клиники НСV−инфекции. Описаны современные возможности лабораторной и инструментальной диагностики заболевания, основные принципы лечения в зависимости от тяжести течения и активности патологического процесса в печени.The achievements in the study of the etiology, pathogenesis and clinical manifestations of HCV infection are discussed. Contemporary capabilities of laboratory and instrumental diagnosis of the disease as well as main principles of treatment depending on the severity of the course and activity of the pathological process in the liver are described

Aerobic power and flight capacity in birds: a phylogenetic test of heart-size hypothesis

Flight capacity is one of the most important innovations in animal evolution; it only evolved in insects, birds, mammals and the extinct pterodactyls. Given that powered flight represents a demanding aerobic activity, an efficient cardiovascular system is essential for the continuous delivery of oxygen to the pectoral muscles during flight. It is well known that the limiting step in the circulation is stroke volume (the volume of blood pumped from the ventricle to the body during each beat), which is determined by the size of the ventricle. Thus, the fresh mass of the heart represents a simple and repeatable anatomical measure of the aerobic power of an animal. Although several authors have compared heart masses across bird species, a phylogenetic comparative analysis is still lacking. By compiling heart sizes for 915 species and applying several statistical procedures controlling for body size and/or testing for adaptive trends in the dataset (e.g. model selection approaches, phylogenetic generalized linear models), we found that (residuals of) heart size is consistently associated with four categories of flight capacity. In general, our results indicate that species exhibiting continuous hovering flight (i.e. hummingbirds) have substantially larger hearts than other groups, species that use flapping flight and gliding show intermediate values, and that species categorized as poor flyers show the smallest values. Our study reveals that on a broad scale, routine flight modes seem to have shaped the energetic requirements of birds sufficiently to be anatomically detected at the comparative level

Potential links between Baltic Sea submarine terraces and groundwater seeping

Submarine groundwater discharge (SGD) influences ocean chemistry, circulation, and the spreading of nutrients and pollutants; it also shapes sea floor morphology. In the Baltic Sea, SGD was linked to the development of terraces and semicircular depressions mapped in an area of the southern Stockholm archipelago, Sweden, in the 1990s. We mapped additional parts of the Stockholm archipelago, areas in Blekinge, southern Sweden, and southern Finland using high-resolution multibeam sonars and sub-bottom profilers to investigate if the sea floor morphological features discovered in the 1990s are widespread and to further address the hypothesis linking their formation to SGD. Sediment coring and sea floor photography conducted with a remotely operated vehicle (ROV) and divers add additional information to the geophysical mapping results. We find that terraces, with general bathymetric expressions of about 1 m and lateral extents of sometimes > 100 m, are widespread in the surveyed areas of the Baltic Sea and are consistently formed in glacial clay. Semicircular depressions, however, are only found in a limited part of a surveyed area east of the island of Asko, southern Stockholm archipelago. While submarine terraces can be produced by several processes, we interpret our results to be in support of the basic hypothesis of terrace formation initially proposed in the 1990s; i.e. groundwater flows through siltier, more permeable layers in glacial clay to discharge at the sea floor, leading to the formation of a sharp terrace when the clay layers above seepage zones are undermined enough to collapse. By linking the terraces to a specific geologic setting, our study further refines the formation hypothesis and thereby forms the foundation for a future assessment of SGD in the Baltic Sea that may use marine geological mapping as a starting point. We propose that SGD through the submarine sea floor terraces is plausible and could be intermittent and linked to periods of higher groundwater levels, implying that to quantify the contribution of freshwater to the Baltic Sea through this potential mechanism, more complex hydrogeological studies are required.Peer reviewe

The Strong Selective Sweep Candidate Gene ADRA2C Does Not Explain Domestication Related Changes In The Stress Response Of Chickens

Analysis of selective sweeps to pinpoint causative genomic regions involved in chicken domestication has revealed a strongselective sweep on chromosome 4 in layer chickens. The autoregulatory a-adrenergic receptor 2C (ADRA2C) gene is theclosest to the selective sweep and was proposed as an important gene in the domestication of layer chickens. The ADRA2Cpromoter region was also hypermethylated in comparison to the non-selected ancestor of all domesticated chicken breeds,the Red Junglefowl, further supporting its relevance. In mice the receptor is involved in the fight-or-flight response as itmodulates epinephrine release from the adrenals. To investigate the involvement of ADRA2C in chicken domestication, wemeasured gene expression in the adrenals and radiolabeled receptor ligand in three brain regions comparing the domesticWhite Leghorn strain with the wild ancestor Red Junglefowl. In adrenals ADRA2C was twofold greater expressed than therelated receptor gene ADRA2A, indicating that ADRA2C is the predominant modulator of epinephrine release but no straindifferences were measured. In hypothalamus and amygdala, regions associated with the stress response, and in striatum,receptor binding pIC50 values ranged between 8.1–8.4, and the level was not influenced by the genotyped allele. Becausechicken strains differ in morphology, physiology and behavior, differences attributed to a single gene may be lost in thenoise caused by the heterogeneous genetic background. Therefore an F10 advanced intercross strain between WhiteLeghorn and Red Junglefowl was used to investigate effects of ADRA2C alleles on fear related behaviors and fecundity. Wedid not find compelling genotype effects in open field, tonic immobility, aerial predator, associative learning or fecundity.Therefore we conclude that ADRA2C is probably not involved in the domestication of the stress response in chicken, and thestrong selective sweep is probably caused by selection of some unknown genetic element in the vicinity of the gene

Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis)

Coronary circulation of the heart evolved early within ectothermic vertebrates and became of vital importance to cardiac performance in some teleost fish, mammals and birds. In contrast, the role and function of the coronary circulation in ectothermic reptiles remains largely unknown. Here, we investigated the systemic and coronary arterial responses of five anesthetized juvenile American alligators (Alligator mississippiensis) to hypoxia, acetylcholine, adenosine, sodium nitroprusside, isoproterenol, and phenylephrine. We recorded electrocardiograms, monitored systemic blood pressure, blood flows in both aortae, and blood flow in a major coronary artery supplying most of the right ventricle. Coronary arterial blood flow was generally forward, but there was a brief retrograde flow during a ventricular contraction. Blood pressure was significantly changed in all conditions. Acetylcholine decreased coronary forward flow, but this response was confounded by the concomitant lowered work of the ventricles due to decreased heart rate and blood pressure. Coronary forward flow was poorly correlated with heart rate and mean arterial pressure across treatments. Overall changes in coronary forward flow, significant and not significant, were generally in the same direction as mean arterial pressure and ventricular power, approximated as the product of systemic cardiac output and mean arterial pressur

Fecundity results from the different genotypes of the F₁₀ intercross strain.

<p>A) total egg count during the 2 week collecting period and B) total egg mass as a percent of body mass. A⁺/A⁺ is wild type, A⁺/A^D is heterozygote and A^D/A^D is domestic genotype. The horizontal line shows the mean value and the dots are the individual data points.</p

ADRA2C abundance from receptor binding assays.

<p>A) Receptor abundance in 3 brain regions with all animals pooled. Abundance in amygdala (B), hypothalamus (C) and striatum (D). The line indicate the mean value and dots indicate individual data points.</p

Adrenergic receptor gene expression in adrenal glands.

<p>A) <i>ADRA2C</i> and B) <i>ADRA2A</i> where the line indicates average value relative to housekeeping genes and the dots are the individual data points.</p

Behavioural variables from Tonic Immobility (TI) and Aerial Predator tests.

<p>A) TI induction attempts and B) TI duration (s). C) and D) Relaxed behavior pre and post exposure to the aerial predator in males (C) and in females (D). Data shown as mean and standard deviation. Star indicates a significant difference between genotypes (p<0.05).</p

Positional information on the location of ADRA2C in relation to a neighboring selective sweep and methylated regions from previous studies.

<p>A) Location of the <i>ADRA2C</i> in chromosome 4 in relation to the selective sweep region reported by Rubin et al. (2010). All coordinates are expressed as kb. The position of the 1229 bp long gene starting at 84590769 is represented by a blue box and the SNP in position 84590997 used for genotyping is shown as a yellow star within the gene. The direction of transcription is indicated with an arrow. The methylation pattern bp long gene starting at 84590769 is represented by a blue box and the SNP in position 84590997 used for genotyping is shown as a yellow star within the gene. The direction of transcription is indicated with an arrow. The methylation pattern (in Log2 fold change) comparing RJF and WL, shown with a resolution of 50–75 bp regions is shown in the bar graph, and the hypermethylated region is highlighted with a red bar at position 84593087. Methylation data from N bp regions is shown in the bar graph, and the hypermethylated region is highlighted with a red bar at position 84593087. Methylation data from Nätt et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103218#pone.0103218-Natt1" target="_blank">[16]</a>. B) Peptide sequence homology phylogeny of the annotated sequences of α₂ adrenergic receptor subtypes cluster the chicken <i>ADRA2C</i> gene to better characterized mammalian ADRA2C genes.</p