bluuebunny/crossref_metadata_2025 huggingface dataset:
A cascade of preventable complications following a missed femoral neck fracture after antegrade femoral nailing
Authors: McDonald Lucas S , Tepolt Frances , Leonardelli Dominic , Hammerberg E Mark , Stahel Philip F
Published: May 2013

Background

Occult femoral neck fractures associated with femoral shaft fractures are frequently missed and may lead to adverse outcomes.

Case presentation

A 46-year old female presented to our institution with increasing groin pain one month after antegrade intramedullary nailing of a femoral shaft fracture at an outside hospital. Radiographic evaluation revealed a displaced ipsilateral femoral neck fracture, adjacent to the piriformis starting point of the nail. A revision fixation of the femoral shaft and neck fracture was performed. The patient sustained a series of complications requiring multiple revision surgeries, including a total hip arthroplasty. Despite the cascade of complications, the patient had an uneventful long-term recovery, without additional complications noted at one-year follow-up.

Conclusion

This case report illustrates the necessity of increased awareness with a high level of suspicion for the presence of associated femoral shaft and neck fractures in any patient undergoing antegrade femoral nailing. Arguably, the cascade of complications presented in this paper could have been prevented with early recognition and initial stabilization of the occult femoral neck fracture. Standardized diagnostic protocols include “on table” pelvic radiographs to rule out associated femoral neck fractures. The diagnosis must be enforced in case of equivocal radiographic findings, either by computed tomography scan or magnetic resonance imaging.
Assessments of A. C. Pigou’s Fellowship Theses
Authors: McLure Michael
Published: May 2013

This study reports on the light that documents stored in the Archive Centre at King's College, Cambridge, shed on A. C. Pigou's fellowship theses. Particular consideration is given to Walter Alexander Raleigh's and Brooke Foss Westcott's assessments of Pigou's first, and unsuccessful, fellowship thesis titled ``Robert Browning as a Religious Teacher'' and to Alfred Marshall's and Herbert Foxwell's assessments of Pigou's second, and successful, fellowship thesis titled ``The Causes and Effects of Change in the Relative Values of Agricultural Produce in the United Kingdom during the Last Fifty Years.'' The principal findings of the study are as follows: Pigou's first thesis is more important to his subsequent and famous studies on wealth and welfare than is generally appreciated; and the assessors' diverse reactions to his second thesis largely reflect their different views on the scope for applying economic theory to reveal insights into concrete economic events that have taken place over time.
The zebrafish common cardinal veins develop by a novel mechanism: lumen ensheathment
Authors: Helker Christian S. M. , Schuermann Annika , Karpanen Terhi , Zeuschner Dagmar , Belting Heinz-Georg , Affolter Markus , Schulte-Merker Stefan , Herzog Wiebke
Published: May 2013

The formation and lumenization of blood vessels has been studied in some detail, but there is little understanding of the morphogenetic mechanisms by which endothelial cells (ECs) forming large caliber vessels aggregate, align themselves and finally form a lumen that can support blood flow. Here, we focus on the development of the zebrafish common cardinal veins (CCVs), which collect all the blood from the embryo and transport it back to the heart. We show that the angioblasts that eventually form the definitive CCVs become specified as a separate population distinct from the angioblasts that form the lateral dorsal aortae. The subsequent development of the CCVs represents a novel mechanism of vessel formation, during which the ECs delaminate and align along the inner surface of an existing luminal space. Thereby, the CCVs are initially established as open-ended endothelial tubes, which extend as single EC sheets along the flow routes of the circulating blood and eventually enclose the entire lumen in a process that we term ‘lumen ensheathment’. Furthermore, we found that the initial delamination of the ECs as well as the directional migration within the EC sheet depend on Cadherin 5 function. By contrast, EC proliferation within the growing CCV is controlled by Vascular endothelial growth factor C, which is provided by circulating erythrocytes. Our findings not only identify a novel mechanism of vascular lumen formation, but also suggest a new form of developmental crosstalk between hematopoietic and endothelial cell lineages.
Sexual recognition and fertilization in brown algae
Authors: Callow J. A.
Published: May 2013

Fertilization in the brown marine algae known as fucoids, is oogamous. The naked egg cell (80 qm diam.) is fertilized by small biflagellate spermatozoids and both monoecious and dioecious species are found. Fertilization is highly species-specific and this appears to be controlled during plasmogamy. Following fusion of egg and sperm, a rapid (< 1 min) release of polyuronide cell wall material takes place from cytoplasmic vesicles within the egg. This is easily visualized using the fluorescent brightener Calcofluor, which therefore provides the basis of a quantitative fertilization bioassay. It has not proved possible to measure direct sperm binding to eggs.

In experiments to investigate the molecular basis of egg-sperm recognition, the effect of exogenous agents on the initial rate of fertilization was examined. Predigestion of eggs with low concentrations of two glycosidases, a-fucosidase and a-mannosidase, caused inhibition of fertilization. The lectins concanavalin A and RCAuo bound strongly to egg surfaces, as detected using fluorescent labels, but not to sperm. The binding to eggs inhibited fertilization. On the other hand, Fucose Binding Protein bound only weakly to eggs but strongly to sperm, again causing inhibition of fertilization. It has not proved possible to quantitate lectin binding since high levels of lectin-nonspecific binding were detected using iodinated lectins. These inhibition experiments suggest that specific sugar residues may be involved in egg-sperm recognition, but the effects of lectins must be treated with caution since a large amount of variability in the sensitivity of gametes was detected.

Attempts to isolate receptor fractions from egg cells have been partially successful. Egg membrane preparations bind sperm and sodium dodecyl sulphate-solubilized fractions, purified by concanavalin A affinity chromatography, have yielded low levels of a soluble receptor-like fraction that has not yet been fully characterized.

Antisera raised against surface antigens of Fucus serratus sperm flagella, cause inhibition of fertilization in a species-specific manner, possibly by binding directly to the sperm fertilization receptor. A number of flagellar antigens were detected and future attempts to pinpoint the sperm receptor will make use of monoclonal antibodies.
Molecular basis of cell recognition during fertilization in higher plants
Authors: Clarke Adrienne E. , Anderson Marilyn A. , Bacic Tony , Harris Philip J. , Mau Shaio-Lim
Published: May 2013

The molecular basis of recognition between plant cells is incompletely understood. Some principles established for recognition between animal cells may well apply to plant cell recognition, although, in contrast to animal cells, plant cells are encased by cell walls that play an active role in plant cell-cell recognition.

The interaction that controls fertilization in flowering plants involves recognition between pollen or pollen tubes and the female sexual tissues. In many flowering plant families, self-incompatibility (S) genes operate to prevent inbreeding. In plants that have gametophytically controlled selfincompatibility, recognition of common S alleles in pollen tube and style results in arrest of pollen tube growth within the style. Self-incompatibility therefore provides a model cell-cell recognition system that is genetically defined.

We have taken two approaches to defining cell recognition involved in gametophytic selfincompatibility in Nicotiana alata. Firstly, we have established the major features of the pollen tube wall and the matrix of the style transmitting tissue that are in contact with the growing pollen tube. Secondly, we have established the nature of style glycoproteins that are associated with the S genotype and have initiated a program to clone the genes coding for the protein component of these glycoproteins.

Analyses of the pollen tube are consistent with the major polymers being a (1→3)-β-D-glucan (callose) and a (1→5)-α -L-arabinan. The pollen tube has two distinct layers: gold immunocytochemistry using a monoclonal antibody directed to terminal a-L-arabinosyl residues shows the binding is confined to the outer layers. The major component of the extracellular matrix of the style transmitting tissue is a family of proteoglycans, the arabinogalactan-proteins.

A major glycoprotein that segregates with the Si allele is present in extracts of mature styles. This component has a high pI (> 9’5) and an apparent molecular weight of 32 × 103. It is not present in extracts of immature styles of N. alata genotypes bearing the Si allele, or in extracts from other organs of N. alata or styles of other members of the Solanaceae. The isolated glycoprotein is an effective inhibitor of in vitro pollen tube growth. This evidence suggests that the Sz-associated glycoprotein is either the product of the Si allele, or a gene closely associated with the S gene. We have prepared a cDNA library from styles of one genotype and are screening this library with mRNA from mature and immature styles. We have also prepared synthetic oligonucleotide probes to N-terminal sequences obtained from the isolated Sz-associated glycoprotein for use in screening the library.

This dual approach for establishing the detailed structures of the interacting components and the genetic basis of the interaction will give us a better understanding of the recognition events involved in self-incompatibility.
Surfaces and secretions in the pollen-stigma interaction: a brief review
Authors: Heslop-Harrison J. , Heslop-Harrison Y.
Published: May 2013

Interactions between pollen and pistil are key events in angiosperm reproduction, and for this reason they have been the target of an increasing volume of research in recent years. The regulation of fertilization has proved to be remarkably complex, involving controls of various kinds imposed at several different levels. Pollen hydration, governance of germination and stigma penetration, guidance and nutrition of the pollen tube in the style -as well as various, still enigmatic, direct interactions between male and female gametophytes -may all be concerned, individually or in combination, in determining whether fertilization will or will not be effected. The controls differ in degree of efficiency and specificity. Depending largely on the taxonomic remoteness of the parents, interspecific incompatibility may result simply from lack of physiological co-adaptation between the partners, or from rejection mechanisms of a more specific kind. Intraspecific incompatibility, although generally having a deceptively simple genetic basis, has proved to be surprisingly diverse in its physiological manifestations. The paper will present a brief conspectus of the present status of research in the field, and review some recent interpretations of the nature of the specific recognition events that may be involved in some of the interactions.
Rhizobium leguminosarum genes involved in early stages of nodulation
Authors: Downie J. A. , Rossen L. , Knight C. D. , Robertson J. G. , Wells B. , Johnston A. W. B.
Published: May 2013

Nodulation genes from Rhizobium leguminosarum have been subcloned and transferred to a strain of R. phaseoli with its symbiotic plasmid deleted (and therefore its nodulation and nitrogen fixation genes). Normal infection and nodule development occurred when these strains were added to the roots of Pisum sativum (peas) and Vicia hirsuta. The pea nodules were examined by electron microscopy; bacteroid forms were seen surrounded by peribacteroid membranes and using immuno-gold labelling it was shown that the nodule cells contained leghaemoglobin within the cytoplasm. By subcloning and analysing the nodulation region it was found that a small (3-2 × 103 bases) fragment of DNA contained three genes involved in root hair curling, the first observed step in the interaction between R. leguminosarum and the root hair cells of these legumes.
Callose biosynthesis as a ca2+-regulated process and possible relations to the induction of other metabolic changes
Authors: Kauss Heinrich
Published: May 2013

Chitosan and poly-L-lysine induce electrolyte leakage in suspension-cultured soy bean cells due to their polycationic nature. Similar effects are caused by Polymyxin B at certain concentrations. After any of these treatments electrolyte leakage is followed by a rapid onset of callose synthesis, as studied quantitatively by its fluorescence with Aniline Blue. In addition to membrane perturbations resulting in membrane leakage callose synthesis requires the presence of external Ca2+ at μM concentrations. It is suggested that concomitant with electrolyte leakage a Ca2+ influx occurs, which leads to a local increase in Ca2+ at the cytoplasmic side of the membrane, resulting in activation of the (1→3)-β-glucan synthase.

The activity of this enzyme in microsomal preparations depends directly and reversibly on Ca2+, with half-saturation at about 5 μM. Inhibitor studies suggest that activation of the (l→3)-β-glucan synthase by Ca2+ is not mediated by calmodulin but possibly by phospholipids. The enzyme can also be activated in vitro by limited proteolysis. However, this type of activation does not appear to be involved in chitosan-elicited callose formation.

It appears of interest in regard to the function of callose in cell and tissue repair mechanisms that its formation is inhibited by unsaturated fatty acids and lysophosphatidylcholine, substances that presumably can result during membrane damage.

Callose synthesis may be regarded as an indicator of chitosan-induced increase in cytoplasmic Ca2+ concentration. It is speculated that this may also be part of the signal chain for initiation of de novo synthesis of enzymes reported to regulate phytoalexin production.
The human interleukin-2 receptor
Authors: Greene Warner C. , Depper Joel M. , KrÖnke Martin , Leonard Warren J.
Published: May 2013

Complementary DNAs corresponding to the human receptor for interleukin-2 (IL-2) have been molecularly cloned, sequenced, and expressed in both COS-1 and L cells. The human genome appears to contain a single structural gene for this receptor located on the short arm of chromosome 10 (band 14-15). However, when transcribed, at least two families of mRNAs are produced, which vary in length due to the use of at least three different polyadenylation signals. Sequence analysis of the cloned cDNAs and Si nuclease protection assays indicate an alternative pathway of mRNA processing for this receptor whereby a 216 base-pair segment contained within the protein coding region is spliced, resulting in an mRNA unable to encode a functional IL-2 receptor. In contrast, cDNAs corresponding to mRNA retaining this 216 base-pair region code membrane receptors that bind both IL-2 and anti-Tac (monoclonal anti-IL-2 receptor antibody). Analysis of the deduced amino acid sequence reveals that the receptor is composed of 272 amino acids including a signal peptide 21 amino acids in length. Hydrophobicity analysis suggests a single, 19 amino acid transmembrane domain. A short intracytoplasmic domain composed of 13 amino acids is present and contains two potential phosphate acceptor sites (serine and threonine but not tyrosine) as well as positively charged residues presumably involved in cytoplasmic anchoring. Two sites for N-linked glycosylation sites and numerous extracytoplasmic O-linked glycosylation sites are present.
Visualization Of The Living Cytoskeleton By Video-Enhanced Microscopy And Digital Image Processing
Authors: Weiss Dieter G.
Published: May 2013

Two steps led to our present-day view of the cytoskeleton as a highly dynamic structure that is actively involved in force generation for various kinds of cell motility and, as a result, is itself often actively moving.

The first step was the introduction of video microscopy, especially of the Allen Video Enhanced Contrast-Differential Interference Contrast Microscopy (AVEC-DIC), which allows the visualization of cellular structures in the light microscope that are up to 10 times smaller than the limit of resolution. This enables one to see images of unfixed, unstained, native or purified microtubules and actin bundles, and their interaction with membrane-bound organelles.

The second step was the discovery of a system exceptionally well-suited to study microtubule and organelle movements, namely, the extruded axoplasm of the squid giant axon. From this axon the cytoplasm can be extruded free from surrounding plasma membrane, and individual microtubules and organelles can be separated from the bulk axoplasm.

The study of these native microtubules by AVEC-DIC microscopy yielded a great number of. quite unexpected details of the dynamic behaviour of both the microtubules themselves and the motility associated with them.
Supracellular Microtubule Alignments In Cell Layers Associated With The Secretion Of Certain Fish Scales
Authors: J. Dane P. , B. Tucker J.
Published: May 2013

Intercellularly aligned microtubule arrays are present in cell layers associated with the growth and secretion of scales in the zebra fish Brachydanio rerio and the neon tetra fish Hyphessobrycon innesi. The layers in question are: the osteoblast layer that covers the ossified outer surface of a scale, and the layer of fibroblasts that is situated immediately underneath the inner collagenous surface of a scale’s fibrillary plate.

In certain osteoblasts, the proximal portions of microtubules (with respect to centrosomes) run closely alongside the anterior margin of each cell where it flanks one of a scale’s ridge-shaped circuit. These osteoblasts and microtubule portions are arranged in aligned rows that are parallel to circuit. However, the distal portions of the microtubules curve into an orientation that is approximately at right angles to circuit and they are aligned with each other and similar microtubule portions in adjacent osteoblasts. Such microtubule alignments only occur in osteoblasts that are associated with circuit. In Hyphessobrycon osteoblasts situated elsewhere on a scale’s surface, microtubules radiate from cell centres but their distal portions curve into alignment with each other and are oriented alongside cell margins.

The proximal portions of fibroblast microtubules radiate from centrally positioned centrosomes but the distal portions curve into alignment with each other and distal microtubule portions in neighbouring fibroblasts. The overall pattern of microtubule alignment is similar to that of collagen fibres, which these fibroblasts are secreting onto the fibrillary plate.

The immunofluorescence protocol that was used to demonstrate the microtubule alignments described above did not reveal such alignments in the osteoblast and fibroblast layers associated with scales of the brown trout Salmo truttafario.

These findings are assessed in terms of intra- and inter-cellular control of microtubule alignment, and decentralized reorientation of microtubules at distances of several micrometres from centrosomal microtubule-organizing centres. The functional significance of the relationships between microtubule alignment and supracellular patterns of alignment that take place as collagen deposition and ossification proceed during scale formation is also considered.
Observations Of Microfilament Bundles In Living Cells Microinjected With Fluorescently Labelled Contractile Proteins
Authors: Sanger Jean M. , Mittal Balraj , Pochapin Mark , Sanger Joseph W.
Published: May 2013

Fluorescently labelled contractile proteins (alpha-actinin and filamin) were used to study the dynamic nature of three types of microfilament bundles: myofibrils, stress fibres and polygonal networks. Cultured muscle and non-muscle cells that were microinjected with fluorescent alphaactinin rapidly incorporated the labelled protein into Z-bands, stress fibre densities and the polygonal foci. Living, injected cells were then observed for varying periods of time, and changes in orientation and periodicity of the myofibrils, stress fibres and polygonal networks were recorded. Permeabilized cells were also reacted with fluorescently labelled proteins and with contractile protein antibodies in order to analyse further the changes taking place in the myofibrils and stress fibres. In both living cardiac myocytes and living skeletal muscle myotubes, contractile myofibrils were present in the same cell with non-contractile nascent myofibrils. The periodicities of small Z-bodies in the nascent non-contractile myofibrils were shorter than the Z-band spacings in the contractile myofibrils, yet both types of myofibrils contained muscle myosin. Over a period of 24 h, a nascent myofibril in a living, microinjected myotube was observed to grow from Z-body spacings of 0·9–1·3µm to full sarcomere spacings (2·3um). During the same time, nascent myofibrils appeared de novo and Z-band alignment became more ordered in the fully formed myofibrils. Stress fibres were not observed to undergo the predictable type of growth seen in myofibrils, but stress fibre periodicities did change in some fibres; some shortened while others lengthened. The orientation of fibres shifted in cytoplasm of both mobile cells and stationary cells. Attachment plaques and foci also changed position and in some cases subdivided and/or disappeared. Models of stress fibres and polygonal networks are presented that suggest that the changes in the periodicities of the dense bodies in stress fibres and the distances between polygonal foci are related to the movement of the interdigitating actin and myosin filaments.
Myosin Distribution And Actin Organization In Different Areas Of Antibody-Labelled Quick-Frozen Fibroblasts
Authors: Lawson Durward
Published: May 2013

In cortical and subcortical areas of motile non-muscle cells myosin is found only on linear actin filament bundles that are aligned with the cell’s long axis. Myosin is absent from actin filaments perpendicular to these bundles and from areas of cortical and subcortical actin, which has a complex geometrical array. These data suggest that in the non-muscle cell myosin exerts force in a unidirectional manner only, as it does in muscle. The presence of myosin up to the ends of cell processes suggests that, even in the cortex, this force transduction takes place over short-range distances. The absence of myosin rods in vivo but the presence of structures corresponding to single myosin molecules suggests that the force-generating unit for actomyosin-based movement in non-muscle cells is either a myosin dimer/small oligomer or single myosin molecule, attached to actin by their tail regions.
The structure and function of a mannose 6-phosphate receptor- enriched, pre-lysosomal compartment in animal cells
Authors: Griffiths Gareth
Published: May 2013

The characteristics of a distinct prelysosomal compartment, evident in many animal cells, are described. The main feature of this compartment is that it is an acidic, tubulo-vesicular late endosome structure that contains high concentrations of the cation-independent mannose 6-phosphate receptor. The pathway to the lysosomes from the early endosomes, as well as that of newly synthesized lysosomal proteins from the trans-Golgi network, appear to converge in this prelysosomal compartment.
Characterisation of the nuclear location sequence of Xenopus nucleoplasmin
Authors: Dingwall Colin , Robbins Jacqueline , Dilworth Stephen M.
Published: May 2013

Each subunit of the Xenopus nucleoplasmin polypeptide possesses a single nuclear location sequence, the boundaries of which have been determined by deletion analysis. However, the sequence identified in this analysis is unable to locate pyruvate kinase to the cell nucleus. Further investigation revealed that while this sequence element is not sufficient for nuclear localisation, it is a necessary feature of slightly longer sequences which can locate pyruvate kinase to the cell nucleus. This unusual feature of the nucleoplasmin sequence suggests testable models for the interaction of this sequence with the transport mechanism, one of which is discussed here.
Pax genes, mutants and molecular function
Authors: Chalepakis Georges , Tremblay Patrick , Gruss Peter
Published: May 2013

The paired domain is a conserved DNA binding motif which was first found in Drosophila segmentation gene products. This paired domain is encoded by a well conserved, paired box DNA sequence, also detected in the genomes of other species. The mouse paired box-containing genes are referred to as Pax genes and are expressed in a distinct spatiotemporal pattern during embryogenesis. Pax proteins are able to bind to specific DNA sequences and modulate transcriptional activity. Interestingly, three different Pax genes have already been shown to correspond to some mouse and human mutants, emphasizing their role as developmental control genes.
The making of a tight junction
Authors: Cereijido M. , González-Mariscal L. , Contreras R. G. , Gallardo J. M. , Garcia-Villegas R. , Valdés J.
Published: May 2013

MDCK (epithelial cells from the dog kidney) plated at confluence, establish tight junctions in 12-15 hours through a process that requires protein synthesis, formation of a ring of actin filaments in close contact with the lateral membrane of the cells, calmodulin, and a Ca2+-dependent exocytic fusion of tight junction (TJ)-associated components. Monolayers incubated in the absence Ca2+ make no TJs. Yet, if Ca2+ is added under these circumstances, TJs are made with a faster kinetics. Ca2+ is needed mainly at a site located on the outer side of the cell membrane, where it activates uvomorulin and triggers the participation of the cellular components mentioned above, via G-proteins associated with phospholipase C and protein kinase C. In principle, the sites of all these molecules and mechanisms involved in junction formation may be where a variety of agents (hormones, drugs, metabolites) act to produce epithelia with a transepithelial electrical resistance (TER) ranging from 10 to 10,000 Q.cm2. This range may be also due to a variety of substances found in serum and in urine, that increase the TER in a reversible and dose-dependent manner.
Polarity signals in epithelial cells
Authors: Rodriguez-Boulan Enrique , Zurzolot Chiara
Published: May 2013

In simple epithelia, specialized vectorial functions such as transport and secretion are made possible by the segregation of proteins and lipids into opposite surface domains. This polarized distribution results from selective delivery to and retention at the appropriate domain. In the case of direct delivery, the sorting site for apical and basolateral proteins is the tram-Golgi network (TGN) where they are incorporated into distinct apical and basolateral vesicles that are targeted to the respective surfaces. The machinery that controls this simple process is in fact rather complicated. It involves many different steps from the recognition event (between ‘sorting signal(s)’ and ‘sorting receptor(s)’) to the formation of the vesicles, their budding, and the docking to the specialized plasma membrane domain. Here we summarize the latest developments in the sorting of apical and basolateral proteins, focusing in particular on the signals that are involved in this process and the current hypotheses about the mechanisms responsible for it, in both epithelia and in non-polarized cells.
Apical junctions and cell signalling in epithelia
Authors: Woods Daniel F. , Bryant Peter J.
Published: May 2013

Genetic analysis in Drosophila has led to the identification of several proteins that mediate cell-cell interactions controlling the fate and proliferation of epithelial cells. These proteins are localized or enriched in the adherens and septate junctions at the apical end of the lateral membranes between cells. The proteins localized or enriched at adherens junctions include Notch, which is important for the cell interactions controlling neuroblast and bristle patterning; Boss and sevenless, which are required for the cell interaction that establishes the R7 photoreceptor cell; and Armadillo, required for the wingless-dependent cell interactions that control segment polarity and imaginai disc patterning. Proteins localized at septate junctions include the product of the tumor suppressor gene dig, which is required for septate junction formation, apical basal cell polarity, and the cell interactions that control proliferation. The results suggest that the cell signalling events important for cell fate determination and for cell proliferation control in epithelia occur at the apical junctions. The migration of the nucleus to the apical surface of the epithelium for mitosis may enable it to interact directly with the junction-associated signalling mechanisms.
Sorting of ion transport proteins in polarized cells
Authors: Gottardi Cara J. , Pietrini Grazia , Roush Denise L. , Caplan Michael J.
Published: May 2013

The plasma membranes of polarized epithelial cells and neurons express distinct populations of ion transport proteins in their differentiated plasma membrane domains. In order to understand the mechanisms responsible for this polarity it will be necessary to elucidate the nature both of sorting signals and of the cellular machinery which recognizes and acts upon them. In our efforts to study sorting signals we have taken advantage of two closely related families of ion transport proteins whose members are concentrated in different epithelial plasmalemmal domains. The H+,K+-ATPase and the Na+,K+-ATPase are closely related members of the E1-E2 family of ion transporting ATPases. Despite their high degree of structural and functional homology, they are concentrated on different surfaces of polarized epithelial cells and pursue distinct routes to the cell surface in cells which manifest a regulated delivery pathway. We have transfected cDNAs encoding these pumps’ subunit polypeptides, as well as chimeras derived from them, in a variety of epithlial and non-epithelial cell types. Our observations suggest that these pumps encode multiple sorting signals whose relative importance and functions may depend upon the cell type in which they are expressed. Recent evidence suggests that the sorting mechanisms employed by epithelial cells may be similar to those which operate in neurons. We have examined this proposition by studying the distributions of ion pumps and neurotransmitter re-uptake cotransporters expressed endogenously and by transfection in neurons and epithelial cells, respectively. We find that one of the classes of proteins we studied obeys the correlation between neuronal and epithelial sorting while another does not. Our data are consistent with the possibility that sorting signals and sorting mechanisms are extremely plastic and can be adapted to different uses in different cell types or under different physiological conditions.
Analysis of the trk NGF receptor tyrosine kinase using recombinant fusion proteins
Authors: Horvath Curt M. , Wolven Amy , Machadeo Debbie , Huber Julie , Boter Lana , Benedetti Marta , Hempstead Barbara , Chao Moses V.
Published: May 2013

Nerve growth factor (NGF) represents a family of structurally related trophic factors, including brain-derived neurotrophin factor (BDNF), neurotrophin-3 (NT-3), NT-4, and NT-5. These neurotrophin factors interact with two classes of receptors, the trk receptor tyrosine kinase family, and the low affinity p75 neurotrophin receptor. To study potential ligand-receptor interactions, recombinant trk fusion proteins have been constructed, and pan-Zrft polyclonal antisera directed against the cytoplasmic tyrosine kinase domain have been generated. The recombinant proteins were assessed for in vitro kinase activity and for the ability of K-252a to inhibit phosphorylation. Antibodies made against the fusion protein recognize all trk family members, and are effective in immunoprecipitation of affinity-crosslinked receptors. Comparative crosslinking indicates that NGF can recognize all trk receptor members, illustrating the large number of potential ligand-receptor interactions between neurotrophins and their receptors.
The influence of 5′ and 3′ end structures on pre-mRNA metabolism
Authors: Lewis Joe D. , Gunderson Samuel I. , Mattaj lain W.
Published: May 2013

The 5′ cap structure of RNA polymerase II transcripts and the po?y(A) tail found at the 3′ end of most mRNAs have been demonstrated to play multiple roles in gene expression and its regulation. In the first part of this review we will concentrate on the role played by the cap in pre-mRNA splicing and how it may contribute to efficient and specific substrate recognition. In the second half, we will discuss the roles that polyadenylation has been demonstated to play in RNA metabolism and will concentrate in particular on an elegant mechanism where regulation of polyadenylation is used to control gene expression.
Modelling, dialogism and the functional cycle: biosemiotic and philosophical insights
Authors: Petrilli Susan , Ponzio Augusto
Published: May 2013

Charles Peirce, Mikhail Bakhtin and Thomas Sebeok all develop original research itineraries around the sign and, despite terminological differences, can be related with reference to the concept of dialogism and modelling. Jakob von Uexküll's biosemiosic "functional cycle", a model for semiosic processes, is also implied in the relation between dialogue and communication. Biological models which describe communication as a self-referential, autopoietic and semiotically closed system (e.g., the models proposed by Maturana, Varela, and Thure von Uexküll) contrast with both the linear (Shannon and Weaver) and the circular (Saussure) paradigms. The theory of autopoietic systems is only incompatible with dialogism if reference is to a linear causal model which describes communication as developing from source to destination, or to the conversation model governed by the turning around together rule. Dialogism understood in biosemiotic terms overlaps with the concepts of interconnectivity, interrelation, intercorporeity and presupposes the otherness relation. As Uexküll says, the relation with the umwelt in nonhuman living beings is stable and concerns the species; on the contrary, in human beings it is, changeable and concerns the single individual, which is at once an advantage and a disadvantage. Thanks to "syntactics", human beings can construct, deconstruct and reconstruct an infinite number of worlds from a finite number of elements. This distinguishes human beings from other animals and determines their capacity for posing problems and asking questions. The human being not only produces his or her own world, but can also endanger it, and even destroy it to the point of causing the extinction of all other life forms on Earth. The unique capacity for reflection on signs makes human beings responsible for life across the planet, both human and nonhuman. Such reflections shift semiotic research in the direction of semioethics.
Rola gubernatora stanowego w australijskim systemie konstytucyjnym
Authors: Rajca Dorota
Published: May 2013

The role of State Governor in the Australian constitutional system

The office of Governor is the oldest constitutional office in Australia. Each of the six states was founded as a British colony, and a Governor was appointed by the British government to exercise executive authority over the colony, to represent the monarch who was permanently based in London and to perform the same constitutional and representational functions at state level, which the Governor General perform at the federal level. Current position of state governor in the Australian political system is the result of the transformation of the office, taking place from the eighteenth century, when the governors led newly emerging British colonies, as well as political and social changes in Australia and in the British Empire. The article presents the history of that office, requirements for officials and a range of their privileges and powers. The evolution of this position will be undoubtedly associated with the result of discussion on a key constitutional change, which is currently pending between the two environments: Australians for a Constitutional Monarchy and Australian Republican Movement.
Finansowanie mediów publicznych w polityce medialnej UE
Authors: Miżejewski Maciej
Published: May 2013

Financing of public service broadcasting in the EU media policy. Examples of Poland, Hungary, France and Germany The article analyzes the issue of financing the public media as one of the most complex and controversial part of media policy in the European Union. European institutions have not opted for the specific model of financing, leaving the case to the member states. Using the examples of Poland and Hungary, the author shows how a broadcasting fee can be a bargaining chip for political purposes, and the announcements of the liquidation of such fees in election campaigns can result in further weak position of public broadcasters. In Hungary, receiving further grants and debt relief managed by the government was perceived as „payment for services” to the public broadcaster, rendered in favor of the ruling coalition. On the other hand, indicated examples of France and Germany show how consistently implemented media policy can create stable conditions for the development of public service broadcasters in those countries and provides protection of media pluralism.
Ziemiański ekonomista Jan Mittelstaedt i jego retrospektywna utopia
Authors: Grzybek Dariusz
Published: May 2013

Jan Mittelstaedt – country gentleman – economist and his retrospective utopia

This paper presents ideas of Polish gentry economist from 19th century Jan Mittelstaedt (1819‑1890). He was probably the last polish conservative thinker openly defending serfdom and hostile to idea of giving peasants full property of land. Mittelstaedt supported model of great landlords’ ownership in polish agriculture and free trade in international relations, openly backed agricultural specialization of polish economy. He fought against nearly all political and cultural consequences of modernization but eagerly followed technical progress. As an economist he mixed fundamental ideas of classical political economy and his own excentric ideas. In Mittelstaedts economics religion and virtue are the last sources of economic welfare. He thought that is still possible the restoration of major role of Christian Religion in culture and ordinary life. As a consequence of this ideas he promoted concept of ‘common union of men of virtue’ stressing other people to moral conduct. However Mittelstaedt thinking seems archaic, it has many similarities to contemporary catholic free market thought, following both – technical excellence of capitalism and moral tradition of Christianity.
Cattle Review
Authors: Barrett David C
Published: May 2013

Introduction: This edition of Cattle Review considers papers on stillbirth and dystocia, attitudes to pain and analgesia.
Weight loss and abortion in a Thoroughbred broodmare
Authors: Rendle David
Published: May 2013

The following report describes the investigation of weight loss and abortion in a Thoroughbred broodmare. The mare was identified to have systolic and diastolic heart murmurs and haematological and clinical chemical examinations revealed a marked inflammatory response. The mare was subsequently diagnosed with bacterial endocarditis affecting both the mitral and aortic valves and was subjected to euthanasia in view of the hopeless prognosis. The characteristic clinical and pathological findings of bacterial endocarditis are discussed.
Lipid and Inflammatory Cardiovascular Risk Worsens Over 3 Years in Youth With Type 2 Diabetes
Authors:   TODAY Study Group
Published: May 2013

OBJECTIVE

Type 2 diabetes increases cardiovascular risk. We examined lipid profiles and inflammatory markers in 699 youth with recent-onset type 2 diabetes in the TODAY clinical trial and compared changes across treatment groups: metformin alone (M), metformin plus rosiglitazone (M+R), and metformin plus intensive lifestyle program (M+L).

RESEARCH DESIGN AND METHODS

Multiethnic youth with type 2 diabetes received M, M+R, or M+L. Statin drugs were begun for LDL cholesterol (LDL) ≥130 mg/dL or triglycerides ≥300 mg/dL. Lipids, apolipoprotein B (apoB), LDL particle size, high-sensitivity c-reactive protein (hsCRP), homocysteine, plasminogen activator inhibitor-1 (PAI-1), and HbA1c were measured over 36 months or until loss of glycemic control.

RESULTS

LDL, apoB, triglycerides, and non-HDL cholesterol (HDL) rose over 12 months and then stabilized over the next 24 months. Participants with LDL ≥130 mg/dL or using LDL-lowering therapy increased from 4.5 to 10.7% over 36 months, while 55.9% remained at LDL goal (<100 mg/dL) over that time. Treatment group did not impact LDL, apoB, or non-HDL. Small dense LDL (particle size, ≤0.263 relative flotation rate) was most common in M. Triglycerides were lower in M+L than M, and M+L attenuated the negative effect of hyperglycemia on triglycerides and HDL in females. hsCRP, PAI-1, and homocysteine increased over time. However, hsCRP was lower in M+R compared with M or M+L.

CONCLUSIONS

Dyslipidemia and chronic inflammation were common in youth with type 2 diabetes and worsened over time. Diabetes treatment, despite some treatment group differences in lipid and inflammatory marker change over time, is generally inadequate to control this worsening risk.
Efficacy and Safety of Lixisenatide Once Daily Versus Exenatide Twice Daily in Type 2 Diabetes Inadequately Controlled on Metformin
Authors: Rosenstock Julio , Raccah Denis , Korányi László , Maffei Laura , Boka Gabor , Miossec Patrick , Gerich John E.
Published: May 2013

OBJECTIVE

To compare efficacy and safety of lixisenatide once daily versus exenatide twice daily in type 2 diabetes inadequately controlled with metformin.

RESEARCH DESIGN AND METHODS

Adults with diabetes inadequately controlled (HbA1c 7–10%) with metformin were randomized to lixisenatide 20 μg once daily (n = 318) or exenatide 10 μg twice daily (n = 316) in a 24-week (main period), open-label, parallel-group, multicenter study. The primary objective was a noninferiority assessment of lixisenatide versus exenatide in HbA1c change from baseline to week 24.

RESULTS

Lixisenatide once daily demonstrated noninferiority in HbA1c reduction versus exenatide twice daily. The least squares mean change was −0.79% (mean decrease 7.97 to 7.17%) for lixisenatide versus −0.96% (mean decrease 7.96 to 7.01%) for exenatide, and treatment difference was 0.17% (95% CI, 0.033–0.297), meeting a predefined noninferiority upper CI margin of 0.4%. Responder rate (HbA1c <7.0%) and improvements in fasting plasma glucose were comparable. Both agents induced weight loss (from 94.5 to 91.7 kg and from 96.7 to 92.9 kg with lixisenatide and exenatide, respectively). Incidence of adverse events (AEs) was similar for lixisenatide and exenatide, as was incidence of serious AEs (2.8 and 2.2%, respectively). Discontinuations attributable to AEs occurred in 33 lixisenatide (10.4%) and 41 exenatide (13.0%) patients. In the lixisenatide group, fewer participants experienced symptomatic hypoglycemia (2.5 vs. 7.9%; P < 0.05), with fewer gastrointestinal events (especially nausea; 24.5 vs. 35.1%; P < 0.05).

CONCLUSIONS

Add-on lixisenatide once daily in type 2 diabetes inadequately controlled with metformin demonstrated noninferior improvements in HbA1c, with slightly lower mean weight loss, lower incidence of hypoglycemia, and better gastrointestinal tolerability compared with exenatide twice daily.
The Chromatin Landscape of Kaposi’s Sarcoma-Associated Herpesvirus
Authors: Toth Zsolt , Brulois Kevin , Jung Jae
Published: May 2013

Kaposi’s sarcoma-associated herpesvirus is an oncogenic γ-herpesvirus that causes latent infection in humans. In cells, the viral genome adopts a highly organized chromatin structure, which is controlled by a wide variety of cellular and viral chromatin regulatory factors. In the past few years, interrogation of the chromatinized KSHV genome by whole genome-analyzing tools revealed that the complex chromatin landscape spanning the viral genome in infected cells has important regulatory roles during the viral life cycle. This review summarizes the most recent findings regarding the role of histone modifications, histone modifying enzymes, DNA methylation, microRNAs, non-coding RNAs and the nuclear organization of the KSHV epigenome in the regulation of latent and lytic viral gene expression programs as well as their connection to KSHV-associated pathogenesis.
Artémis et le sacrifice préliminaire au combat
Authors: Vernant Jean-Pierre
Published: May 2013

Artémis n'est pas une divinité guerrière. Dans les conflits armés où son rôle est parfois décisif, elle n'agit pas en combattante ; elle guide et elle sauve. La déesse intervient dans les situations extrêmes quand la guerre tend à sortir du cadre civilisé où la maintiennent les règles du combat entre Grecs pour basculer dans la sauvagerie d'une violence sans frein.

On examine, de ce point de vue, l'usage d'égorger une chèvre à Artémis en préliminaire au combat. Tant que sur la victime immolée devant le front des troupes les signes ne se sont pas montrés favorables, pour l'armée rangée immobile en ordre de bataille la consigne de partir à l'attaque ne saurait être donnée. Il faut l'accord et comme la caution de la déesse pour que l'assaut réglé des rangs d'hoplites ne risque pas de déboucher dans la confusion de la panique et de la déroute ou dans la fureur sauvage du massacre.
La Théomachie de Nonnos et ses antécédents
Authors: Vian Francis
Published: May 2013

En composant sa théomachie (Dion. 36, 3, 133), Nonnos suit d'abord fidèlement Homère, puis il donne du conflit une interprétation conforme à l'exégèse allégorique d'Heraclite. L'épisode n'est pas un hors-d'œuvre rhétorique : il aboutit à la réconciliation des dieux qui implique que rien ne viendra désormais contrecarrer le destin. Les théomachies d'Homère et de Quintus de Smyrne ont une signification théologique analogue, souvent méconnue. — L'étude amène à traiter des apparentes incohérences du récit nonnien, qui sont en fait la marque de son art poétique ; elle comporte aussi deux notes critiques concernant Dion. 24, 43-52, et 36, 11.
Les Erinyes dans la tragédie grecque
Authors: Lloyd-Jones Hugh
Published: May 2013

L'équivalence Érinyes-Euménides a été mise en doute. A. Brown (Class. Quart., 1984) a prétendu que les Semnai Theai de l'Aréopage n'étaient pas les Érinyes. C'était faire bon marché des données de l'histoire religieuse, qui permettent de suivre l'évolution de ces divinités, connues dès l'époque mycénienne : elles châtient les meurtriers et finissent par apparaître comme protection de la justice en général. La pièce d'Eschyle a gardé le souvenir de cette ancienne évolution et les Érinyes y sont appelées semnai. Le nom d'Euménides, qui leur était donné par euphémisme, n'est pas une invention d'Euripide (dans son Oreste). Le rôle qu'elles jouent dans Œdipe à Colone montre bien que l'équivalence avec les Érinyes était familière aux Athéniens depuis longtemps.
La régulation du marché du crédit foncier en Égypte
Authors: Abdel Latif Mohamed
Published: May 2013

La loi n° 2001-148 sur le crédit foncier en Égypte est la loi la plus récente de toutes les lois portant sur la régulation des activités économiques et financières. Paradoxalement, le régime de régulation qu’elle met en place encourt le plus de critiques. D’une part, le statut de l’autorité chargée de la régulation du crédit foncier s’avère inadapté à sa mission et ne présente aucune originalité. D’autre part, l’action de cette autorité n’a pas abouti à des résultats très positifs et paraît même incapable de contribuer à l’animation du marché. Cet article a pour objet de justifier cette appréciation.