Transitional reef-to-basin facies of Lower Frasnian limestones determined by microfacies analysis (Wietrznia,Holy Cross Mts,Poland)

Wietrznia section is situated between the shallow-water carbonate platform in the Kielce region and the Łysogóry basin. The transitional facies of the Wietrznia Frasnian includes two overlapping types of deposits: (1) thin-bedded dark-coloured limestone-marl alternations similar to the basin facies and (2) coarse-grained detrital limestones. Three lithotypes of limestones were identified: laminated or graded micritic, nodular, and detrital. The petrographic study makes it possible for the recognition of six major microfacies (MF 1 to MF 6). These lithotypes were formed by redeposition in a low- to high-energy environment. Their source material was the stromatoporoid-coral Dyminy reef in the central part of the Kielce region. Storms are considered to be the main agent, which causes in erosion and transport; micritic limestones and distal tempestites occur together, whereas detrital limestones are associated with proximal tempestites. Most probably, part of the detrital beds was formed as a result of grain-flow initiated under storm conditions.     

The crystal structure and mutational binding analysis of the extracellular domain of the platelet-activating receptor CLEC-2

The human C-type lectin-like molecule CLEC-2 is expressed on the surface of platelets and signaling through CLEC-2 causes platelet activation and aggregation. CLEC-2 is a receptor for the platelet-aggregating snake venom protein rhodocytin. It is also a newly identified co-receptor for human immunodeficiency virus type 1 (HIV-1). An endogenous ligand has not yet been identified. We have solved the crystal structure of the extracellular domain of CLEC-2 to 1.6-A resolution, and identified the key structural features involved in ligand binding. A semi-helical loop region and flanking residues dominate the surface that is available for ligand binding. The precise distribution of hydrophobic and electrostatic features in this loop will determine the nature of any endogenous ligand with which it can interact. Major ligand-induced conformational change in CLEC-2 is unlikely as its overall fold is compact and robust. However, ligand binding could induce a tilt of a 3-10 helical portion of the long loop region. Mutational analysis and surface plasmon resonance binding studies support these observations. This study provides a framework for understanding the effects of rhodocytin venom binding on CLEC-2 and for understanding the nature of likely endogenous ligands and will provide a basis for rational design of drugs to block ligand binding.     

Beta-endorphin levels in longtailed and pigtailed macaques vary by abnormal behavior rating and sex

Frequent or severe abnormal behavior may be associated with the release of endorphins that positively reinforce the behavior with an opiate euphoria or analgesia. One line of research exploring this association involves the superhormone, proopiomelanocortin (POMC). The products of POMC appear to be dysregulated in some human subjects who exhibit self-injurious behavior (SIB). Macaque monkeys have POMC very similar to humans, and some laboratory macaques display SIB or frequent stereotypies. We investigated associations between plasma levels of three immunoreactive POMC fragments with possible opioid action and abnormal behavior ratings in macaques. In 58 adult male and female macaques (24 Macaca fascicularis and 34 Macaca nemestrina), plasma levels of intact beta-endorphin (betaE) and the N-terminal fragment (BEN) were significantly higher in animals with higher levels of abnormal behavior. The C-terminal fragment (BEC) was significantly higher in males but unrelated to ratings of abnormal behavior. Levels of ACTH, cortisol, and (betaE-ACTH)/betaE dysregulation index were unrelated to abnormal behavior. None of the POMC products differed significantly by subjects' species, age, or weight. The finding that intact beta-endorphin is positively related to abnormal behavior in two species of macaque is consistent with some previous research on human subjects and nonprimates. The positive relation of the N-terminal fragment of betaE to abnormal behavior is a new finding.     

The interleukin-1 receptor antagonist gene and the inhibitor of kappa B-like protein gene polymorphisms are not associated with myocardial infarction in Slovene population with type 2 diabetes

In this study we investigated the association of the interleukin-1 receptor antagonist gene variable number tandem repeat (IL1RN VNTR) polymorphism and of the inhibitor of kappa B-like protein (IKBL) gene polymorphism with myocardial infarction (MI) in a group of patients with type 2 diabetes. The IL1RN VNTR and the IKBL+ 738T > C gene polymorphisms were tested in 374 Caucasians: 151 cases with MI and 223 subjects with no history of coronary artery disease. The IL1RN VNTR polymorphism was not a risk factor for MI in Caucasians with type 2 diabetes (genotype 22 vs. the rest: odds ratio (OR) 1.6; 95% confidence interval (CI) = 0.8-3.5; p = 0.2). We also failed to demonstrate that IKBL+ 738T > C gene polymorphism was associated with MI in patients with type 2 diabetes (OR = 0.9; 95% CI = 0.3-2.6; p = 0.9). We provide evidence that the IL1RN VNTR and the IKBL + 738T > C gene polymorphisms are not risk factors for MI in Caucasians with type 2 diabetes.     

Cremated human and animal remains of the Roman period--microscopic method of analysis (Sepkovcica, Croatia)

Human and animal cremated osteological remains from twelve graves of Roman Period from archaeological site Sepkovcica near Velika Gorica (Turopolje region, NW Croatia) were analysed. Beside the content of urns and grave pits, fillings of grave vessels like bowls, pots and amphoras from twentytwo grave samples were included in this study. The preservation of osteological and dental remains of human and animal origin was very poor, majority of fragments hardly reach lengths of 10 mm. Weight of each specimen barely exceeds 100 g per person. Apart from traditional macroscopic methods of analysing cremated remains, microscopic method for determination of age at death was also tested. Fragments of femoral bone diaphysis of eighteen persons whose remains had been found on the site were analysed. Person's age at death was presented in the range of five or ten years, and the long bone fragments of a child (infants) were detected. Taxonomic position for each analysed specimen was determined by microscopic analysis of animal cremated bones. Analysis results confirm validity of microscopic method in determination of age at death for human remains and taxonomic qualification of cremated animal remains from archaeological sites.     

Ligands and signaling of the G-protein-coupled receptor GPR14, expressed in human kidney cells.

Activation of the urotensin II (U-II) receptor, GPR14, leads to an increase in Ca(2+), activation of phospholipase A(2) (PLA(2)) and an increase in arachidonic acid. The signaling pathway for guanylin peptides in the kidney involves an unknown G-protein coupled receptor which activates PLA(2) and increases arachidonic acid as well. To test if guanylin peptides could be, as U-II, agonists for the GPR14 receptor in the kidney, we used HEK293 and CHO cells transfected with hGPR14 (HEK293+hGPR14, CHO+hGPR14, respectively). Effects of guanylin peptides and U-II were studied by slow-whole-cell patch-clamp analysis and microfluorimetric measurements of intracellular Ca(2+). Guanylin peptides and U-II depolarized HEK293+hGPR14 significantly more than wild type cells. These effects were inhibited in the presence of Ba(2+) or PLA(2) inhibition (AACOCF(3)), suggesting that guanylin peptides and U-II increase arachidonic acid and inhibit ROMK channels in these cells. However, only U-II was capable to increase the cellular Ca(2+), suggesting different mechanism of GPR14 activation by guanylin peptides and U-II. This signaling pathway of U-II involves PKC, because U-II effects in HEK293+hGPR14 cells were inhibited by calphostin C. Guanylin peptides activate PLA(2) and inhibit ROMK channels in HEK293 cells transfected with the human GPR14 receptor. Since GPR14 is present in mouse and human CCD it is a candidate for the guanylate cyclase independent receptor for guanylin peptides.     

Reptilian transferrins: evolution of disulphide bridges and conservation of iron-binding center

Transferrins, found in invertebrates and vertebrates, form a physiologically important family of proteins playing a major role in iron acquisition and transport, defense against microbial pathogens, growth and differentiation. These proteins are bilobal in structure and each lobe is composed of two domains divided by a cleft harboring an iron atom. Vertebrate transferrins comprise of serotransferrins, lactoferrins and ovotransferrins. In mammals serotransferrins transport iron in physiological fluids and deliver it to cells, while lactoferrins scavenge iron, limiting its availability to invading microbes. In oviparous vertebrates there is only one transferrin gene, expressed either in the liver to be delivered to physiological fluids as serotransferrin, or in the oviduct with a final localization in egg white as ovotransferrin. Being products of one gene sero- and ovotransferrin are identical at the amino-acid sequence level but with different, cell specific glycosylation patterns. Our knowledge of the mechanisms of transferrin iron binding and release is based on sequence and structural data obtained for human serotransferrin and hen and duck ovotransferrins. No sequence information about other ovotransferrins was available until our recent publication of turkey, ostrich, and red-eared turtle (TtrF) ovotransferrin mRNA sequences [Ciuraszkiewicz, J., Olczak, M., Watorek, W., 2006. Isolation, cloning and sequencing of transferrins from red-eared turtle, African ostrich and turkey. Comp. Biochem. Physiol. 143 B, 301-310]. In the present paper, ten new reptilian mRNA transferrin sequences obtained from the Nile crocodile (NtrF), bearded dragon (BtrF), Cuban brown anole (AtrF), veiled and Mediterranean chameleons (VtrF and KtrF), sand lizard (StrF), leopard gecko (LtrF), Burmese python (PtrF), African house snake (HtrF), and grass snake (GtrF) are presented and analyzed. Nile crocodile and red-eared turtle transferrins have a disulphide bridge pattern identical to known bird homologues. A partially different disulphide bridge pattern was found in the Squamata (snakes and lizards). The possibility of a unique interdomain disulphide bridge was predicted for LtrF. Differences were found in iron-binding centers from those of previously known transferrins. Substitutions were found in the iron-chelating residues of StrF and TtrF and in the synergistic anion-binding residues of NtrF. In snakes, the transferrin (PtrF, HtrF and GtrF) N-lobe "dilysine trigger" occurring in all other known transferrins was not found, which indicates a different mechanism of iron release.