Anthropogenic pressure explains variations in the biodiversity of pond communities along environmental gradients: a case study in south-eastern Serbia

Hydrobiologia - Identifying the evolutionary and developmental bases of adaptive phenotypes is of central interest in evolutionary biology. Cichlid fishes have been a useful research model due to...     

Genome-wide meta-analysis identifies novel gender specific loci associated with thyroid antibodies level in Croatians

Autoimmune thyroid diseases (AITD) are multifactorial endocrine diseases most frequently accompanied by Tg and TPO autoantibodies. Both antibodies have a higher prevalence in females and act under a strong genetic influence.To identify novel variants underlying thyroid antibody levels, we performed GWAS meta-analysis on the plasma levels of TgAb and TPOAb in three Croatian cohorts, as well as gender specific GWAS and a bivariate analysis.No significant association was detected with the level of TgAb and TPOAb in the meta-analysis of GWAS or bivariate results for all individuals. The bivariate analysis in females only revealed a genome-wide significant association for the locus near GRIN3A (rs4457391, P = 7.76 × 10^?9). The same locus had borderline association with TPOAb levels in females (rs1935377, P = 8.58 × 10^?8).In conclusion, we identified a novel gender specific locus associated with TgAb and TPOAb levels. Our findings provide a novel insight into genetic and gender differences associated with thyroid antibodies.     

Rapid prenatal diagnosis of numerical aberrations of chromosome 21 and 18 by PCR-STR method

In this study we reported the results for the first time of applying Polymerase Chain Reaction-Short Tandem Repeats (PCR-STR) method in the field of detection of aneuploidies for chromosomes 21 and 18 in Croatians. The aims of the study were: (I) validation of the diagnostic informativeness of 6 STR loci (D18S51, D18S858, D18S535, D21S1435, D21S1411, and D21S1414) in sample of 205 unrelated healthy individuals; (II) evaluation of diagnostic power of the PCR-STR method for those 6 microsatellites; (III) establishment protocol for use STRs as routine method for rapid prenatal detection of trisomy 21 and 18. DNA samples were amplified by fluorescence-based PCR reaction, subjected to electrophoresis in automated laser fluorescence DNA sequencer (ALFexpress). Results of our study were: (I) all 6 tested loci are informative (68-85% of heterozygous individuals); (II) comparison between PCR-STR method and conventional cytogenetics did not revealed any false positive or false negative results; (III) in prenatal screening of 105 samples of uncultured amniotic fluid 6 (5.7%) samples with chromosomal abnormalities were identified.     

Rab27a regulates phagosomal pH and NADPH oxidase recruitment to dendritic cell phagosomes

To prevent excessive degradation of internalized antigens, which could destroy the peptides recognized by T lymphocytes, dendritic cells have developed several strategies that limit proteolytic activity in phagosomes. The recruitment of the NADPH oxidase NOX2 prevents acidification of phagosomes, limiting antigen degradation. Here, we show that dendritic cells derived from Rab27a-deficient ashen mice show increased phagosome acidification and antigen degradation, causing a defect in antigen cross-presentation. Enhanced acidification results from a delay in the recruitment to phagosomes of a subset of lysosome-related organelles containing the membrane subunits of NOX2. The Rab27a-dependent recruitment of these "inhibitory lysosome-related organelles" to phagosomes continuously limits acidification and degradation of ingested particles in dendritic cells, thus promoting antigen cross-presentation.     

Different aggregation approaches in the chironomid community and the threshold of acceptable information loss

Due to the problem of identification, Chironomidae larvae, although very abundant, are often avoided or not properly used in bioassessment programs. The aim of this work was to test how different aggregation processes—taxonomic resolution and the random aggregation approach (best practicable aggregation of species—BestAgg) affect the analysis of chironomid communities regarding any information loss. The self-organizing map method, together with classification strength analysis and Spearman’s rank correlation, revealed that the genus-level and BestAgg-abundance matrix most accurately approximated the species-level community pattern. The subfamily-level dataset was ineffective at presenting the chironomid community structure, with a substantially lower concordance with the species-level dataset. The biologic environmental gradients analyses presented the same set of important environmental variables for the species-level, genus-level, and BestAgg-abundance matrix. The indicator values analysis showed that indicator genera provide information very close to that gained from species indicators. According to our results, the numeric relationship between species and higher taxa influences taxonomic scaling, limiting Chironomidae family aggregation, with acceptable information loss only up to genus level. In addition, the BestAgg approach, with the maximum level of aggregation, properly assesses the community structure and consequently describes environmental conditions.     

The effects of zolpidem treatment on GABA(A) receptors in cultured cerebellar granule cells: changes in functional coupling

AimsHypnotic zolpidem is a positive allosteric modulator of γ-aminobutyric acid (GABA) action, with preferential although not exclusive binding for α1 subunit-containing GABA_A receptors. The pharmacological profile of this drug is different from that of classical benzodiazepines, although it acts through benzodiazepine binding sites at GABA_A receptors. The aim of this study was to further explore the molecular mechanisms of GABA_A receptor induction by zolpidem.Main methodsIn the present study, we explored the effects of two-day zolpidem (10 μM) treatment on GABA_A receptors on the membranes of rat cerebellar granule cells (CGCs) using [³H]flunitrazepam binding and semi-quantitative PCR analysis.Key findingsTwo-day zolpidem treatment of CGCs did not significantly affect the maximum number (B_max) of [³H]flunitrazepam binding sites or the expression of α1 subunit mRNA. However, as shown by decreased GABA [³H]flunitrazepam binding, two-day exposure of CGCs to zolpidem caused functional uncoupling of GABA and benzodiazepine binding sites at GABA_A receptor complexes.SignificanceIf functional uncoupling of GABA and benzodiazepine binding sites at GABA_A receptors is the mechanism responsible for the development of tolerance following long-term administration of classical benzodiazepines, chronic zolpidem treatment may induce tolerance.     

Maternal genetic legacy of the eastern Adriatic island of Krk--an interplay of evolutionary forces and island's historical events in shaping the genetic structure of contemporary island population

This study presents genetic diversity and structure of contemporary Krk islanders revealed by high-resolution mitochondrial DNA analysis on a sample of 132 unrelated autochthonous adults from seven different settlements and regions of the island. Relatively high level of haplogroup and haplotype diversity in the overall island sample is an indicator of numerous migrations and gene flows throughout the history. Expectedly, the results show the highest frequency of haplogroup H (33.3%), yet this value is much lower compared to different Croatian and other European mainland populations. An interesting finding refers to highly elevated frequencies of some haplogroups, otherwise rare in Croatia and most of the Europe, such as I (11.3%) and W (7.6%) in Krk population, especially pronounced in some settlements. At the level of settlements, many of the major European haplogroups were found to be absent from their mtDNA gene pools, whereas several others show a pronounced deviation from an average. Overall, our results suggest a tangled interplay of different evolutionary forces, such as founder effects and a few strong bottlenecks, presumably due to epidemics, which have occurred in various periods of the island's history. Cultural customs, such as frequent endogamy in some regions of the island during past centuries, have additionally shaped its genetic structure into the observed present-day diversity patterns.     

Patients in cardiac rehabilitation programme--where we were in 1999 and where 10 years later

The aim of this study was to find out and compare characteristics of cardiac patients who, after hospital treatment, participated in cardiac rehabilitation programmes at the Polyclinic for Cardiovascular Prevention and Rehabilitation in Zagreb during 1999 and 2009. The results show an increase in mean patients' age (men: 55.5 to 61.53; p = 0.000 and women: 58.95 to 62.66; p = 0.01), an increase of the proportion of those +/- 65 years by 23% in both genders (men: 17% to 40%; women: 27% to 50%), an increase in the proportion of women (21.16% to 28.22%), a marked increase in the proportion of post - PCI patients with stenting (men: 15.58% to 61.92%; women: 9.68% to 62.20%), reduction of patients with BMI < 25.00 kg/m2 (men: 47.19% to 13.93%; women: 54.84% to 24.41%) and a constantly high proportion of patients with hypercholesterolemia (above 85%). It is obvious that systematic action is required to improve awareness of risk factors and desirable health behaviour.