Phylogenetic relationships and biogeographical patterns in Circum-Mediterranean subfamily Leuciscinae (Teleostei,Cyprinidae) inferred from both mitochondrial and nuclear data

Background  

Leuciscinae is a subfamily belonging to the Cyprinidae fish family that is widely distributed in Circum-Mediterranean region. Many efforts have been carried out to deciphering the evolutionary history of this group. Thus, different biogeographical scenarios have tried to explain the colonization of Europe and Mediterranean area by cyprinids, such as the "north dispersal" or the "Lago Mare dispersal" models. Most recently, Pleistocene glaciations influenced the distribution of leuciscins, especially in North and Central Europe. Weighing up these biogeographical scenarios, this paper constitutes not only the first attempt at deciphering the mitochondrial and nuclear relationships of Mediterranean leuciscins but also a test of biogeographical hypotheses that could have determined the current distribution of Circum-Mediterranean leuciscins.     

Mapping of unfolding states of integral helical membrane proteins by GPS-NMR and scattering techniques: TFE-induced unfolding of KcsA in DDM surfactant

Membrane proteins are vital for biological function, and their action is governed by structural properties critically depending on their interactions with the membranes. This has motivated considerable interest in studies of membrane protein folding and unfolding. Here the structural changes induced by unfolding of an integral membrane protein, namely TFE-induced unfolding of KcsA solubilized by the n-dodecyl β-d-maltoside (DDM) surfactant is investigated by the recently introduced GPS-NMR (Global Protein folding State mapping by multivariate NMR) (Malmendal et al., PlosONE 5, e10262 (2010)) along with dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). GPS-NMR is used as a tool for fast analysis of the protein unfolding processes upon external perturbation, and DLS and SAXS are used for further structural characterization of the unfolding states. The combination allows addressing detergent properties and protein conformations at the same time. The mapping of the states reveals that KcsA undergoes a series of rearrangements which include expansion of the tetramer in several steps followed by dissociation into monomers at 29% TFE. Supplementary studies of DDM and TFE in the absence of KcsA suggest that the disintegration of the tetramer at 29% TFE is caused by TFE dissolving the surrounding DDM rim. Above 34% TFE, KcsA collapses to a new structure that is fully formed at 44% TFE.     

Biomechanical and clinical alterations of the hip joint following femoral neck fracture and implantation of bipolar hip endoprosthesis

The implantation of a bipolar partial hip endoprosthesis is a treatment of choice for displaced medial femoral neck fracture. We present an experimental study which asses and compare biomechanical and clinical status through period before and after hip fracture and implantation of bipolar partial hip endoprosthesis. This study encompassed 75 patients who suffered from an acute medial femoral neck fracture and were treated with the implantation of a bipolar partial hip endoprosthesis. Their biomechanical status (stress distribution on the hip joint weight bearing area) and clinical status (Harris Hip Score) were estimated for the time prior to the injury and assessed at the follow-up examination that was, on average, carried out 40 months after the operation. Despite ageing, the observed Harris Hip Score at the follow-up examination was higher than that estimated prior to the injury (77.9 > 69.6; p = 0.006). Similarly, the hip stress distribution was reduced (2.7 MPa < 2.3 MPa; p = 0.001). While this reduction can be attributed to a loss of weight due to late ageing, the principal improvement came from the operative treatment and corresponding restoration of the biomechanical properties of the hip joint. The implantation of a bipolar partial hip endoprosthesis for patients with displaced medial femoral neck fractures improves the biomechanical and clinical features of the hip, what should have on mind during making decision about treatment.     

To whom do national days matter? A comparison of national belonging across generations and ethnic groups in the Netherlands

This paper studies to what extent participating in days for national commemoration and celebration is associated with feelings of national belonging, and to what extent this is comparable across generations and ethnic groups. Utilizing data from a national survey (N = 4,505), three major national days in the Netherlands are examined. We find that whereas participation in Queen's Day is associated with national belonging for all generations, for Remembrance Day this holds only for the generation born between 1945 and 1955, and for Liberation Day for the generations born after 1955. Moreover, for citizens with a non-Western origin, participating in national days is associated with national belonging more strongly than for citizens with a native Dutch or other Western background. These findings highlight the importance of paying attention to potential group differences in the association between participation in national days and feelings of national belonging.     

Investigations on synthesis and structure elucidation of novel [1,2,4]triazolo[1,2-a]pyridazine-1-thiones and their inhibitory activity against inducible nitric oxide synthase

The inducible nitric oxide synthase (iNOS) is a target of great research interest due to its importance in a number of diseases, for example, septic shock and inflammatory lung diseases. A variety of 3-substituted [1,2,4]triazolo[1,2-a]pyridazine derivatives was synthesized by ring closure with hexahydropyridazine-1-carbothioamide by using aliphatic and aromatic aldehydes. The activity of the new substances was tested on the insulin-secreting rat insulinoma cell line RINm5F. iNOS was expressed through exposure to interleukin-1β (IL-1β) and interferon-γ (IFN-γ). A number of the investigated compounds were more active than the reference inhibitor aminoguanidine (AG). Structure–activity relationships showed that a phenyl substituent in position 3 is apparently essential for inhibition.     

Activation of the zymogen to urokinase-type plasminogen activator is associated with increased interdomain flexibility

A key regulatory step for serine proteases of the trypsin clan is activation of the initially secreted zymogens, leading to an increase in activity by orders of magnitude. Zymogen activation occurs by cleavage of a single peptide bond near the N-terminus of the catalytic domain. Besides the catalytic domain, most serine proteases have N-terminal A-chains with independently folded domains. Little is known about how zymogen activation affects the interplay between domains. This question is investigated with urokinase-type plasminogen activator (uPA), which has an epidermal growth factor domain and a kringle domain, connected to the catalytic domain by a 15-residue linker. uPA has been implicated under several pathological conditions, and one possibility for pharmacological control is targeting the conversion of the zymogen pro-uPA to active uPA. Therefore, a small-angle X-ray scattering study of the conformations of pro-uPA and uPA in solution was performed. Structural models for the proteins were derived using available atomic-resolution structures for the various domains. Active uPA was found to be flexible with a random conformation of the amino-terminal fragment domain with respect to the serine protease domain. In contrast, pro-uPA was observed to be rigid, with the amino-terminal fragment domain in a fixed position with respect to the serine protease domain. Analytical ultracentrifugation analysis supported the observed difference between pro-uPA and uPA in overall shape and size seen with small-angle X-ray scattering. Upon association of either of two monoclonal Fab (fragment antigen-binding) fragments that are directed against the catalytic domain of, respectively, pro-uPA and uPA, rigid structures were formed.     

Expression and localization of four uroplakins in urothelial preneoplastic lesions

In superficial umbrella cells of normal urothelium, uroplakins (UPs) are assembled into urothelial plaques, which form fusiform vesicles (FVs) and microridges of the apical cell surface. Altered urothelial differentiation causes changes in the cell surface structure. Here, we investigated ultrastructural localization of UPIa, UPIb, UPII and UPIIIa in normal and cyclophosphamide-induced preneoplastic mouse urothelium. In normal urothelium, terminally differentiated umbrella cells expressed all four UPs, which were localized to the large urothelial plaques covering mature FVs and the apical plasma membrane. The preneoplastic urothelium contained two types of superficial cells with altered differentiation: (1) poorly differentiated cells with microvilli and small, round vesicles that were uroplakin-negative; no urothelial plaques were observed in these cells; (2) partially differentiated cells with ropy ridges contained uroplakin-positive immature fusiform vesicles and the apical plasma membrane. Freeze-fracturing showed small urothelial plaques in these cells. We concluded that in normal urothelium, all four UPs colocalize in urothelial plaques. However, in preneoplastic urothelium, the growth of the uroplakin plaques was hindered in the partially differentiated cells, leading to the formation of immature FVs and ropy ridges instead of mature FVs and microridges. Our study demonstrates that despite a lower level of expression, UPIa, UPIb, UPII and UPIIIa maintain their plaque association in urothelial preneoplastic lesions.