Significant genetic differentiation between Poland and Germany follows present-day political borders, as revealed by Y-chromosome analysis

To test for human population substructure and to investigate human population history we have analysed Y-chromosome diversity using seven microsatellites (Y-STRs) and ten binary markers (Y-SNPs) in samples from eight regionally distributed populations from Poland (n=913) and 11 from Germany (n=1,215). Based on data from both Y-chromosome marker systems, which we found to be highly correlated (r=0.96), and using spatial analysis of the molecular variance (SAMOVA), we revealed statistically significant support for two groups of populations: (1) all Polish populations and (2) all German populations. By means of analysis of the molecular variance (AMOVA) we observed a large and statistically significant proportion of 14% (for Y-SNPs) and 15% (for Y-STRs) of the respective total genetic variation being explained between both countries. The same population differentiation was detected using Monmoniers algorithm, with a resulting genetic border between Poland and Germany that closely resembles the course of the political border between both countries. The observed genetic differentiation was mainly, but not exclusively, due to the frequency distribution of two Y-SNP haplogroups and their associated Y-STR haplotypes: R1a1*, most frequent in Poland, and R1*(xR1a1), most frequent in Germany. We suggest here that the pronounced population differentiation between the two geographically neighbouring countries, Poland and Germany, is the consequence of very recent events in human population history, namely the forced human resettlement of many millions of Germans and Poles during and, especially, shortly after World War II. In addition, our findings have consequences for the forensic application of Y-chromosome markers, strongly supporting the implementation of population substructure into forensic Y chromosome databases, and also for genetic association studies.     

Effects of chronic administration of clenbuterol on function and metabolism of adult rat cardiac muscle

Clenbuterol (Clen), a beta(2)-agonist, is known to produce skeletal and myocardial hypertrophy. This compound has recently been used in combination with left ventricular assist devices for the treatment of end-stage heart failure to reverse or prevent the adverse effects of unloading-induced myocardial atrophy. However, the mechanisms of action of Clen on myocardial cells have not been fully elucidated. In an attempt to clarify this issue, we examined the effects of chronic administration of Clen on Ca(2+) handling and substrate preference in cardiac muscle. Rats were treated with either 2 mg x kg(-1) x day(-1) Clen or saline (Sal) for 4 wk with the use of osmotic minipumps. Ventricular myocytes were enzymatically dissociated. Cells were field stimulated at 0.5, 1, and 2 Hz, and cytoplasmic Ca(2+) transients were monitored with the use of the fluorescent indicator indo-1 acetoxymethyl ester. Two-dimensional surface area and action potentials in current clamp were also measured. We found that in the Clen group there was significant hypertrophy at the organ and cellular levels compared with Sal. In Clen myocytes, the amplitude of the indo-1 ratio transients was significantly increased. Sarcoplasmic reticulum Ca(2+) content, estimated by rapid application of 20 mM caffeine, was significantly increased in the Clen group. The action potential was prolonged in the Clen group compared with Sal. Carbohydrate contribution to the tricarboxylic cycle (Krebs cycle) flux was increased several times in the Clen group. This increase was associated with decreased expression of peroxisome proliferator-activated receptor-alpha. This study shows that chronic administration of Clen induces cellular hypertrophy and increases oxidative carbohydrate utilization together with an increase in sarcoplasmic reticulum Ca(2+) content, which results in increased amplitude of the Ca(2+) transients. These effects could be important when Clen is used in conjunction with left ventricular assist devices treatment.     

Metabolism of phenolic compounds in <Emphasis Type="Italic">Vitis riparia</Emphasis> seeds during stratification and during germination under optimal and low temperature stress conditions

We studied the alterations in phenolic compounds in grape seeds during their stratification and germination under optimal conditions (+25 °C) and at low temperature (+10 °C). Biological materials in the study were seeds of Vitis riparia. Phenolic compounds were extracted from defatted seeds using 80 % methanol or 80 % acetone. The content of total phenolics was determined with the Folin-Ciocalteau reagent, while the content of tannins was determined by vanillin assay and the protein (BSA) precipitation method. The RP-HPLC method was used to determine phenolic compounds (phenolic acids, catechins) in the extracts. High amounts of tannins, catechins, gallic acid and lesser amounts of p-coumaric acid were found in the seeds. The content of total phenolics in acetone extracts was higher than that obtained using methanol. The amounts of phenolic acids and tannins found in V. riparia seeds after stratification were much lower. It may confirm a possible role of these compounds in dormancy of V. riparia seeds. After 72 h of low temperature treatment, inhibition of grape root growth and biochemical changes in seeds were detected. The chilling stimulated increased accumulation of some phenolic compounds (free gallic acid and catechins) in the seeds. These substances can protect plants against some abiotic stressors.     

Predicting protein function from sequence and structural data

When a protein's function cannot be experimentally determined, it can often be inferred from sequence similarity. Should this process fail, analysis of the protein structure can provide functional clues or confirm tentative functional assignments inferred from the sequence. Many structure-based approaches exist (e.g. fold similarity, three-dimensional templates), but as no single method can be expected to be successful in all cases, a more prudent approach involves combining multiple methods. Several automated servers that integrate evidence from multiple sources have been released this year and particular improvements have been seen with methods utilizing the Gene Ontology functional annotation schema.     

New derivatives of picolinic acid and nicotinic acid with anticonvulsant activity

Previously obtained Pic-BZA is a potent anticonvulsant with low neurotoxicity, but its half-time of action is only about 15 min. In search for equally effective anticonvulsants but with a longer time of action fourteen Pic-BZA analogs were obtained. The compounds were evaluated in the Anticonvulsant Screening Project (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH. Picolinic acid 2-fluorobenzylamide (Pic-2-F-BZA, 7) appeared to be the most effective compound of the series.     

Novel, flexible, and conformationally defined analogs of gepirone: synthesis and 5-HT1A, 5-HT2A, and D2 receptor activity

Novel, flexible arylpiperazine gepirone analogs (1a-3a) with a mixed 5-HT1A/5-HT2A receptor profile, low D2 receptor affinity, and agonistic (2a) or partial agonistic (1a, 3a) activity toward 5-HT1A receptor sites were synthesized. Their conformationally restricted counterparts (1b-3b) were selective 5-HT1A ligands (over 5-HT2A and D2 receptors), which turned out to be agonists (2b, 3b), or partial agonist (1b) of 5-HT1A receptors.     

Role of acidic amino acid residues in chitooligosaccharide-binding to Streptomyces sp. N174 chitosanase

We examined the oligosaccharide binding to Streptomyces sp. N174 chitosanase by fluorescence spectroscopy. By means of the tryptophan fluorescence quenching, the oligosaccharide binding abilities were evaluated using the three mutant enzymes (D57A, E197A, and D201A). The enzymatic activities of the mutant enzymes were 0.5%, 20.0%, and 38.5% of that of the wild type, respectively. Scatchard plot obtained for the wild type enzyme showed a biphasic profile, suggesting that the oligosaccharide binds to the chitosanase with two different binding sites (the high affinity site and the low affinity site). In contrast, Scatchard plot for E197A exhibited a monophasic profile, in which the slope of the line corresponds to that for the low affinity binding of the wild type enzyme. A monophasic profile was also obtained for D201A, but the slope of the line was similar to that of the high affinity binding. Thus, we conclude that Glu197 and Asp201 are responsible for oligosaccharide binding at the high affinity site and the low affinity site, respectively, which correspond to the (-n) subsites and the (+n) subsites (n=1, 2, and 3). The fluorescence quenching was very weak in D57A, suggesting a strong contribution of this residue to the oligosaccharide binding.     

Anticandidal properties of N-acylpeptides containing an inhibitor of glucosamine-6-phosphate synthase

A series of N-acyl peptides 1-9, containing an inhibitor of glucosamine-6-phosphate synthase have been synthesised and tested against Candida strains. N-Acylated peptides inhibit glucosamine-6-phosphate synthase in cell free extracts from Candida albicans. Antifungal activities of the tested compounds correlated with their lipophilic properties. Peptides acylated with decanoic acid were found to be the most potent in the series. N-decanoylpeptides also showed activity against Candida albicans Gu5 resistant mutant with Cdr1 and Cdr2 drug extrusion proteins that causes MDR by an active efflux mechanism.     

Novel dinucleoside 5',5'-triphosphate cap analogues. Synthesis and affinity for murine translation factor eIF4E

Chemical synthesis of a series of novel dinucleoside cap analogues, m7GpppN, where N is formycin A, 3'-O-methylguanosine, 9-beta-D-arabinofuranosyladenine, and isoguanosine, has been performed using our new methodology. The key reactions of pyrophosphate bonds formation were achieved in anhydrous dimethylformamide solutions employing the catalytic properties of zinc salts. Structures of the new cap analogues were confirmed by 1H NMR and 31p NMR spectra. The binding affinity of the new cap analogues for murine eIF4E(28-217) were determined spectroscopically showing the highest association constant for the analogue that contains formycin A.     

Folding thermodynamics and kinetics of YNMG RNA hairpins: specific incorporation of 8-bromoguanosine leads to stabilization by enhancement of the folding rate

Modified nucleotides allow fundamental energetic and kinetic properties of nucleic acids to be probed. Here, we demonstrate that an RNA hairpin containing the nucleotide analogue 8-bromoguanosine (8BrG or G), gcUUCGgc, has enhanced stability relative to the unmodified hairpin, with DeltaDeltaG(37)(degrees)= -0.69 +/- 0.15 kcal mol(-1) and DeltaT(M) = +6.8 +/- 1.4 degrees C. NMR spectroscopic data suggest that the enhanced stability of gcUUCGgc does not arise from the native state; laser temperature-jump experiments support this notion, as gcUUCGgc and gcUUCGgc have similar unfolding rate constants, but the folding rate constant of gcUUCGgc is 4.1-fold faster at 37.5 degrees C and 2.8-fold faster under isoenergetic conditions. On the basis of these findings, we propose that 8BrG reduces the conformational entropy of the denatured state, resulting in an accelerated conformational search for the native state and enhanced stability.