bluuebunny/crossref_metadata_2025 huggingface dataset:
A yeast three-hybrid system that reconstitutes mammalian hypoxia inducible factor regulatory machinery
Authors: Alcaide-German Maria L , Vara-Vega Alicia , Garcia-Fernandez Luis F , Landazuri Manuel O , del Peso Luis
Published: April 2008

Background

Several human pathologies, including neoplasia and ischemic cardiovascular diseases, course with an unbalance between oxygen supply and demand (hypoxia). Cells within hypoxic regions respond with the induction of a specific genetic program, under the control of the Hypoxia Inducible Factor (HIF), that mediates their adaptation to the lack of oxygen. The activity of HIF is mainly regulated by the EGL-nine homolog (EGLN) enzymes that hydroxylate the alpha subunit of this transcription factor in an oxygen-dependent reaction. Hydroxylated HIF is then recognized and ubiquitinilated by the product of the tumor suppressor gene, pVHL, leading to its proteosomal degradation. Under hypoxia, the hydroxylation of HIF by the EGLNs is compromised due to the lack of oxygen, which is a reaction cosubstrate. Thus, HIF escapes degradation and drives the transcription of its target genes. Since the progression of the aforementioned pathologies might be influenced by activation of HIF-target genes, development of small molecules with the ability to interfere with the HIF-regulatory machinery is of great interest.

Results

Herein we describe a yeast three-hybrid system that reconstitutes mammalian HIF regulation by the EGLNs and VHL. In this system, yeast growth, under specific nutrient restrictions, is driven by the interaction between the β domain of VHL and a hydroxyproline-containing HIFα peptide. In turn, this interaction is strictly dependent on EGLN activity that hydroxylates the HIFα peptide. Importantly, this system accurately preserves the specificity of the hydroxylation reaction toward specific substrates. We propose that this system, in combination with a matched control, can be used as a simple and inexpensive assay to identify molecules that specifically modulate EGLN activity. As a proof of principle we show that two known EGLN inhibitors, dimethyloxaloylglycine (DMOG) and 6-chlor-3-hydroxychinolin-2-carbonic acid-N-carboxymethylamide (S956711), have a profound and specific effect on the yeast HIF/EGLN/VHL system.

Conclusion

The system described in this work accurately reconstitutes HIF regulation while preserving EGLN substrate specificity. Thus, it is a valuable tool to study HIF regulation, and particularly EGLN biochemistry, in a cellular context. In addition, we demonstrate that this system can be used to identify specific inhibitors of the EGLN enzymes.
Axon-bearing and axon-less horizontal cell subtypes are generated consecutively during chick retinal development from progenitors that are sensitive to follistatin
Authors: Edqvist Per-Henrik D , Lek Madelen , Boije Henrik , Lindbäck Sarah M , Hallböök Finn
Published: April 2008

Background

Horizontal cells are retinal interneurons that modulate the output from photoreceptors. A rich literature on the morphological classification and functional properties of HCs in different animals exists, however, the understanding of the events underlying their development is still limited. In most vertebrates including chicken, two main horizontal cell (HC) subtypes are identified based on the presence or absence of an axon.

Results

In this work we have molecularly characterized three HC subtypes based on Lim1, Isl1, GABA and TrkA, a classification that is consistent with three chick HC subtypes previously defined by morphology. The axon-bearing and axon-less HC subpopulations molecularly defined by Lim1 and Isl1, are born consecutively on embryonic day (E) 3–4 and E4–5, respectively, and exhibit temporally distinguishable periods of migration. Their relative numbers are not adjusted by apoptosis. A sharp decrease of high endogenous levels of the activin-inhibitor follistatin at E3 coincides with the appearance of the Lim1 positive cells. Extending the follistatin exposure of the HC retinal progenitor cells by injection of follistatin at E3 increased the number of both Lim1- and Isl1 positive HCs when analysed at E9.

Conclusion

The results imply that the axon-bearing and axon-less HC subgroups are defined early and are generated consecutively from a retinal progenitor cell population that is sensitive to the inhibitory action of follistatin. The results are consistent with a model wherein added follistatin causes HC-generating progenitors to proliferate beyond the normal period of HC generation, thus producing extra HCs of both types that migrate to the HC layer.
Expression patterns of protein kinase D 3 during mouse development
Authors: Ellwanger Kornelia , Pfizenmaier Klaus , Lutz Sylke , Hausser Angelika
Published: April 2008

Background

The PKD family of serine/threonine kinases comprises a single member in Drosophila (dPKD), two isoforms in C. elegans (DKF-1 and 2) and three members, PKD1, PKD2 and PKD3 in mammals. PKD1 and PKD2 have been the focus of most studies up to date, which implicate these enzymes in very diverse cellular functions, including Golgi organization and plasma membrane directed transport, immune responses, apoptosis and cell proliferation. Concerning PKD3, a role in the formation of vesicular transport carriers at the trans-Golgi network (TGN) and in basal glucose transport has been inferred from in vitro studies. So far, however, the physiological functions of the kinase during development remain unknown.

Results

We have examined the expression pattern of PKD3 during the development of mouse embryos by immunohistochemistry. Using a PKD3 specific antibody we demonstrate that the kinase is differentially expressed during organogenesis. In the developing heart a strong PKD3 expression is constantly detected from E10 to E16.5. From E12.5 on PKD3 is increasingly expressed in neuronal as well as in the supporting connective tissue and in skeletal muscles.

Conclusion

The data presented support an important role for PKD3 during development of these tissues.
Burkholderia pseudomallei genome plasticity associated with genomic island variation
Authors: Tumapa Sarinna , Holden Matthew TG , Vesaratchavest Mongkol , Wuthiekanun Vanaporn , Limmathurotsakul Direk , Chierakul Wirongrong , Feil Edward J , Currie Bart J , Day Nicholas PJ , Nierman William C , Peacock Sharon J
Published: April 2008

Background

Burkholderia pseudomallei is a soil-dwelling saprophyte and the cause of melioidosis. Horizontal gene transfer contributes to the genetic diversity of this pathogen and may be an important determinant of virulence potential. The genome contains genomic island (GI) regions that encode a broad array of functions. Although there is some evidence for the variable distribution of genomic islands in B. pseudomallei isolates, little is known about the extent of variation between related strains or their association with disease or environmental survival.

Results

Five islands from B. pseudomallei strain K96243 were chosen as representatives of different types of genomic islands present in this strain, and their presence investigated in other B. pseudomallei. In silico analysis of 10 B. pseudomallei genome sequences provided evidence for the variable presence of these regions, together with micro-evolutionary changes that generate GI diversity. The diversity of GIs in 186 isolates from NE Thailand (83 environmental and 103 clinical isolates) was investigated using multiplex PCR screening. The proportion of all isolates positive by PCR ranged from 12% for a prophage-like island (GI 9), to 76% for a metabolic island (GI 16). The presence of each of the five GIs did not differ between environmental and disease-associated isolates (p > 0.05 for all five islands). The cumulative number of GIs per isolate for the 186 isolates ranged from 0 to 5 (median 2, IQR 1 to 3). The distribution of cumulative GI number did not differ between environmental and disease-associated isolates (p = 0.27). The presence of GIs was defined for the three largest clones in this collection (each defined as a single sequence type, ST, by multilocus sequence typing); these were ST 70 (n = 15 isolates), ST 54 (n = 11), and ST 167 (n = 9). The rapid loss and/or acquisition of gene islands was observed within individual clones. Comparisons were drawn between isolates obtained from the environment and from patients with melioidosis in order to examine the role of genomic islands in virulence and clinical associations. There was no reproducible association between the individual or cumulative presence of five GIs and a range of clinical features in 103 patients with melioidosis.

Conclusion

Horizontal gene transfer of mobile genetic elements can rapidly alter the gene repertoire of B. pseudomallei. This study confirms the utility of a range of approaches in defining the presence and significance of genomic variation in natural populations of B. pseudomallei.
Identification of Tmem10/Opalin as a novel marker for oligodendrocytes using gene expression profiling
Authors: Kippert Angelika , Trajkovic Katarina , Fitzner Dirk , Opitz Lennart , Simons Mikael
Published: April 2008

Background

During the development of the central nervous system, oligodendrocytes generate large amounts of myelin, a multilayered insulating membrane that ensheathes axons, thereby allowing the fast conduction of the action potential and maintaining axonal integrity. Differentiation of oligodendrocytes to myelin-forming cells requires the downregulation of RhoA GTPase activity.

Results

To gain insights into the molecular mechanisms of oligodendrocyte differentiation, we performed microarray expression profiling of the oligodendroglial cell line, Oli-neu, treated with the Rho kinase (ROCK) inhibitor, Y-27632 or with conditioned neuronal medium. This resulted in the identification of the transmembrane protein 10 (Tmem10/Opalin), a novel type I transmembrane protein enriched in differentiating oligodendrocytes. In primary cultures, Tmem10 was abundantly expressed in O4-positive oligodendrocytes, but not in oligodendroglial precursor cells, astrocytes, microglia or neurons. In mature oligodendrocytes Tmem10 was enriched in the rims and processes of the cells and was only found to a lesser extent in the membrane sheets.

Conclusion

Together, our results demonstrate that Tmem10 is a novel marker for in vitro generated oligodendrocytes.
The Infant Feeding Activity and Nutrition Trial (INFANT) an early intervention to prevent childhood obesity: Cluster-randomised controlled trial
Authors: Campbell Karen , Hesketh Kylie , Crawford David , Salmon Jo , Ball Kylie , McCallum Zoë
Published: April 2008

Background

Multiple factors combine to support a compelling case for interventions that target the development of obesity-promoting behaviours (poor diet, low physical activity and high sedentary behaviour) from their inception. These factors include the rapidly increasing prevalence of fatness throughout childhood, the instigation of obesity-promoting behaviours in infancy, and the tracking of these behaviours from childhood through to adolescence and adulthood. The Infant Feeding Activity and Nutrition Trial (INFANT) aims to determine the effectiveness of an early childhood obesity prevention intervention delivered to first-time parents. The intervention, conducted with parents over the infant's first 18 months of life, will use existing social networks (first-time parent's groups) and an anticipatory guidance framework focusing on parenting skills which support the development of positive diet and physical activity behaviours, and reduced sedentary behaviours in infancy.

Methods/Design

This cluster-randomised controlled trial, with first-time parent groups as the unit of randomisation, will be conducted with a sample of 600 first-time parents and their newborn children who attend the first-time parents' group at Maternal and Child Health Centres. Using a two-stage sampling process, local government areas in Victoria, Australia will be randomly selected at the first stage. At the second stage, a proportional sample of first-time parent groups within selected local government areas will be randomly selected and invited to participate. Informed consent will be obtained and groups will then be randomly allocated to the intervention or control group.

Discussion

The early years hold promise as a time in which obesity prevention may be most effective. To our knowledge this will be the first randomised trial internationally to demonstrate whether an early health promotion program delivered to first-time parents in their existing social groups promotes healthy eating, physical activity and reduced sedentary behaviours. If proven to be effective, INFANT may protect children from the development of obesity and its associated social and economic costs.

Trial registration

Current Controlled Trials ISRCTN81847050
Verifiability of diagnostic categories and work ability in the context of disability pension award: A survey on "gatekeeping" among general practitioners in Norway
Authors: Overland Rein , Overland Simon , Johansen Kristian Nyborg , Mykletun Arnstein
Published: April 2008

Background

Disability benefits exist to redeem social and financial consequences of reduced work ability from medical conditions. Physicians are responsible for identifying the medical grounds for benefit claims. The aim of this study was to explore physicians' views on verifiability of medical conditions and related work ability in this context.

Methods

Information on verifiability of diagnostic categories and work ability was obtained from a survey among a representative sample of general practitioners (GPs) in Norway (n = 500, 25.2% response rate). Verifiability was defined as to what extent the assessment is based on objective criteria versus on information from the patient. We enquired about the diagnostic categories used in official statistics on main disability benefit causes in Norway and elsewhere.

Results

On a scale from 0 (low verifiability) to 5 (high verifiability), the mean level of verifiability across all diagnostic categories was 3.7 (SD = 0.42). Degree of verifiability varied much between diagnostic categories, and was low in e.g. unspecified rheumatism/myalgia and dorsopathies, and high in neoplasms and congenital malformations, deformation and chromosomal abnormalities. Verifiability of work ability was reported to be more problematic than that of diagnostic categories. The diagnostic categories rated as the least verifiable, are also the most common in disability pension awards.

Conclusion

Verifiability of both diagnostic categories and work ability in disability assessments are reported to be moderate by GPs. We suggest that the low verifiability of diagnostic categories and related work ability assessments in the majority of disability pension awards is important in explaining why GPs find the gatekeeping-function problematic.
Use of a commercial enzyme immunoassay to monitor dengue virus replication in cultured cells
Authors: Ludert Juan E , Mosso Clemente , Ceballos-Olvera Ivonne , del Angel Rosa M
Published: April 2008

Current methods for dengue virus quantitation are either time consuming, technically demanding or costly. As an alternative, the commercial enzyme immunoassay Platelia™ Dengue NS1 AG (Bio-Rad Laboratories) was used to monitor semiquantitatively dengue virus replication in cultured cells. The presence of NS1 protein was evaluated in supernatants from Vero and C6/36 HT cells infected with dengue virus. The amount of NS1 detected in the supernatants of infected cells was proportional to the initial MOI used and to the time of post infection harvest. This immunoassay was also able to detect the presence of NS1 in the supernatants of infected human macrophages. Inhibition of dengue virus replication in C6/36 HT cells treated with lysosomotropic drugs was readily monitored with the use of this assay. These results suggest that the Platelia™ Dengue NS1 AG kit can be used as a fast and reliable surrogate method for the relative quantitation of dengue virus replication in cultured cells.
Phenotype prediction in regulated metabolic networks
Authors: Kaleta Christoph , Centler Florian , di Fenizio Pietro Speroni , Dittrich Peter
Published: April 2008

Background

Due to the growing amount of biological knowledge that is incorporated into metabolic network models, their analysis has become more and more challenging. Here, we examine the capabilities of the recently introduced chemical organization theory (OT) to ease this task. Considering only network stoichiometry, the theory allows the prediction of all potentially persistent species sets and therewith rigorously relates the structure of a network to its potential dynamics. By this, the phenotypes implied by a metabolic network can be predicted without the need for explicit knowledge of the detailed reaction kinetics.

Results

We propose an approach to deal with regulation – and especially inhibitory interactions – in chemical organization theory. One advantage of this approach is that the metabolic network and its regulation are represented in an integrated way as one reaction network. To demonstrate the feasibility of this approach we examine a model by Covert and Palsson (J Biol Chem, 277(31), 2002) of the central metabolism ofE. colithat incorporates the regulation of all involved genes. Our method correctly predicts the known growth phenotypes on 16 different substrates. Without specific assumptions, organization theory correctly predicts the lethality of knockout experiments in 101 out of 116 cases. Taking into account the same model specific assumptions as in the regulatory flux balance analysis (rFBA) by Covert and Palsson, the same performance is achieved (106 correctly predicted cases). Two model specific assumptions had to be considered: first, we have to assume that secreted molecules do not influence the regulatory system, and second, that metabolites with increasing concentrations indicate a lethal state.

Conclusion

The introduced approach to model a metabolic network and its regulation in an integrated way as one reaction network makes organization analysis a universal technique to study the potential behavior of biological network models. Applying multiple methods like OT and rFBA is shown to be valuable to uncover critical assumptions and helps to improve model coherence.
A systems biology approach to analyse amplification in the JAK2-STAT5 signalling pathway
Authors: Vera Julio , Bachmann Julie , Pfeifer Andrea C , Becker Verena , Hormiga Jose A , Darias Nestor V Torres , Timmer Jens , Klingmüller Ursula , Wolkenhauer Olaf
Published: April 2008

Background

The amplification of signals, defined as an increase in the intensity of a signal through networks of intracellular reactions, is considered one of the essential properties in many cell signalling pathways. Despite of the apparent importance of signal amplification, there have been few attempts to formalise this concept.

Results

In this work we investigate the amplification and responsiveness of the JAK2-STAT5 pathway using a kinetic model. The recruitment of EpoR to the plasma membrane, activation by Epo, and deactivation of the EpoR/JAK2 complex are considered as well as the activation and nucleocytoplasmic shuttling of STAT5. Using qualitative biological knowledge, we first establish the structure of a general power-law model. We then generate a family of models from which we select suitable candidates. The parameter values of the model are estimated from experimental quantitative time-course data. The final model, whether it is conventional model with fixed predefined integer kinetic orders or a model with variable non-integer kinetic orders, is selected on the basis of a good agreement between simulations and the experimental data. The model is used to analyse the responsiveness and amplification properties of the pathway with sustained, transient, and oscillatory stimulation.

Conclusion

The selected kinetic model predicts that the system acts as an amplifier with maximum amplification and sensitivity for input signals whose intensity match physiological values for Epo concentration and with duration in the range of one to 100 minutes. The response of the system reaches saturation for more intense and longer stimulation with Epo. We hypothesise that these properties of the system directly relate to the saturation of Epo receptor activation, its low recruitment to the plasma membrane and intense deactivation as predicted by the model.
Evolutionary potentials: structure specific knowledge-based potentials exploiting the evolutionary record of sequence homologs
Authors: Panjkovich Alejandro , Melo Francisco , Marti-Renom Marc A
Published: April 2008

We introduce a new type of knowledge-based potentials for protein structure prediction, called 'evolutionary potentials', which are derived using a single experimental protein structure and all three-dimensional models of its homologous sequences. The new potentials have been benchmarked against other knowledge-based potentials, resulting in a significant increase in accuracy for model assessment. In contrast to standard knowledge-based potentials, we propose that evolutionary potentials capture key determinants of thermodynamic stability and specific sequence constraints required for fast folding.
The acute phase protein haptoglobin regulates host immunity
Authors: Huntoon Kristin M , Wang Yanping , Eppolito Cheryl A , Barbour Karen W , Berger Franklin G , Shrikant Protul A , Baumann Heinz
Published: April 2008

The contribution of acute phase plasma proteins to host immune responses remains poorly characterized. To better understand the role of the acute phase reactant and major hemoglobin-binding protein haptoglobin (Hp) on the function of immune cells, we generated Hp-deficient C57BL/6J mice. These mice exhibit stunted development of lymphoid organs associated with lower counts of mature T and B cells in the blood and secondary lymphoid compartments. Moreover, these mice show markedly reduced adaptive immune responses as represented by reduced accumulation of IgG antibody after immunization with adjuvant and nominal antigen, abrogation of Th1-dominated delayed-type hypersensitivity reaction, loss of mitogenic responses mounted by T cells, and reduced T cell responses conveyed by APCs. Collectively, these defects are in agreement with the observations that Hp-deficient mice are not capable of generating a recall response or deterring a Salmonella infection as well as failing to generate tumor antigen-specific responses. The administration of Hp to lymphocytes in tissue culture partially ameliorates these functional defects, lending further support to our contention that the acute phase response protein Hp has the ability to regulate immune cell responses and host immunity. The phenotype of Hp-deficient mice suggests a major regulatory activity for Hp in supporting proliferation and functional differentiation of B and T cells as part of homeostasis and in response to antigen stimulation.
Murine gammaherpesvirus-induced fibrosis is associated with the development of alternatively activated macrophages
Authors: Gangadharan Babunilayam , Hoeve Marieke A , Allen Judith E , Ebrahimi Bahram , Rhind Susan M , Dutia Bernadette M , Nash Anthony A
Published: April 2008

Murine gammaherpesvirus 68 (MHV-68) is a natural pathogen of rodents closely related to the human γherpesviruses Kaposi’s sarcoma-associated herpesvirus and EBV. Following intranasal infection, the virus replicates in the lung epithelium prior to establishing latent infection in lymphoid tissue. Infection of mice deficient in IFN-γR signaling (IFN-γR−/−) results in a multiple organ fibrosis, in which the spleen is severely affected. We show here that by Day 12 postinfection, prior to development of fibrosis in the spleens of IFN-γR−/− mice, different subsets of splenic macrophages (Mϕs) are morphologically activated and enter latently infected germinal centers (GCs). Mϕs coexpressing arginase I (ARG1), a marker of alternative activation of Mϕs, and murine Mϕ markers F4/80, ER-TR9, and MOMA-1 are found in GCs of IFN-γR−/− mice but not of wild-type mice. Quantitative RT-PCR of spleen RNA confirms induction of ARG1 and in addition, shows up-regulation of found in inflammatory zone 1/resistin-like molecule-α, tissue inhibitor of metalloproteinase-1, matrix metalloproteinase-12, fibronectin, and factor XIIIA in IFN-γR−/− mice. In contrast, inducible NO synthase, associated with classical Mϕ activation, is up-regulated following infection of wild-type mice but not IFN-γR−/− mice. Concomitant with the aaMϕs, transcription of the Th2 cytokines IL-13, IL-21, and IL-5 is up-regulated. Thus, in the absence of IFN-γR signaling, MHV-68 initiates a Th2 immune response, leading to alternative activation of macrophages and induction of fibrosis. This system provides an important model for studying the pathogenesis of fibrosis initiated by a latent herpesvirus infection.
Thrombin-induced expression of endothelial CX3CL1 potentiates monocyte CCL2 production and transendothelial migration
Authors: Popovic Milan , Laumonnier Yves , Burysek Ladislav , Syrovets Tatiana , Simmet Thomas
Published: April 2008

CX3CL1 (fractalkine, neurotactin) is the sole CX3C chemokine. It induces monocyte locomotion in its cleaved form, but in its membrane-anchored form, it also acts as an adhesion molecule. The expression of CX3CL1 is up-regulated in endothelial cells by proinflammatory cytokines such as IL-1 or TNF-α. Here, we studied the effect of the serine protease thrombin on endothelial CX3CL1 induction and its putative relevance for monocyte function. In HUVEC, thrombin triggered a time- and concentration-dependent expression of CX3CL1 at the mRNA and the protein level as shown by RT-PCR, Western immunoblotting, and flow cytometric analysis. Thrombin induced CX3CL1 by activating protease-activated receptor 1 (PAR1) as demonstrated by the use of PAR1-activating peptide and the PAR1-specific antagonist SCH 79797. The thrombin-induced CX3CL1 expression was NF-κB-dependent, as shown by EMSA, ELISA, and by inhibition of the NF-κB signaling pathway by the IκB kinase inhibitor acety-11-keto-β-boswellic acid or by transient overexpression of a transdominant-negative form of IκBα. Upon cocultivation of human monocytes with HUVEC, the thrombin-dependent induction of membrane-anchored CX3CL1 in HUVEC triggered monocyte adhesion and an enhanced release of the MCP-1/CCL2 by monocytes and potentiated the monocyte transendothelial migration. Accordingly, the recombinant extracellular domain of CX3CL1 induced CCL2 release by monocytes. Thus, the thrombin-induced monocyte/endothelial cell cross-talk mediated by increased CX3CL1 expression potentiates the CCL2 chemokine generation that might contribute to the recruitment of monocytes into inflamed areas.
Enhanced susceptibility to Con A-induced liver injury in mice transgenic for the intracellular isoform of human TNF receptor type 2
Authors: Bäumel Monika , Lechner Anja , Hehlgans Thomas , Männel Daniela N
Published: April 2008

TNF is a pleiotropic cytokine involved in a variety of inflammatory processes and immune responses. TNF effects are mediated via two distinct membrane receptors: TNFR1 and TNFR2. Investigations concerning regulation and function of TNFR2 revealed a novel TNFR2 isoform in human and mouse cells, termed icp75TNFR, with mainly intracellular localization. As human icp75TNFR is capable of functional interaction with mouse TNF, mouse lines transgenic for the human icp75TNFR were generated and characterized. Transgenic expression was identified in several organs, and soluble human (sh)TNFR2 was detected in serum. shTNFR2 released from transfected cells or peritoneal macrophages of transgenic mice protected from TNF-induced cytotoxicity. Although in vivo, no change in inflammatory reactions was observed in models of septic peritonitis, of colitis, or after stimulation with bacterial LPS, liver injury was strongly enhanced in transgenic mice after Con A challenge. Thus, the functional properties of human icp75TNFR seem to be similar to that of TNFR2, resulting in exacerbation of inflammatory tissue damage, thus revealing the functional importance of TNFR2 in pathophysiological processes.
Transcriptional profiling of human skin-resident Langerhans cells and CD1a+ dermal dendritic cells: differential activation states suggest distinct functions
Authors: Santegoets Saskia J A M , Gibbs Susan , Kroeze Kim , van de Ven Rieneke , Scheper Rik J , Borrebaeck Carl A , de Gruijl Tanja D , Lindstedt Malin
Published: April 2008

In human skin, two main populations of dendritic cells (DC) can be discriminated: dermal DC (DDC) and epidermal Langerhans cells (LC). Although extensively studied, most of the knowledge about DDC and LC phenotype and function is obtained from studying DDC and LC cultured in vitro or DDC and LC migrated from skin explants. These studies have left the exact relationship between steady-state human LC and DDC unclear: in particular, whether CD1a+ DDC represent migrated LC or whether they constitute a separate subset. To gain further insight in the kinship between skin-resident CD1a+ DDC and LC, we analyzed CD1a+ DDC and LC, isolated from steady-state skin samples, by high-density microarray analysis. Results show that the CD1a+ DDC specifically express markers associated with DDC phenotype, such as the macrophage mannose receptor, DC-specific ICAM-grabbing nonintegrin, the scavenger receptor CD36, coagulation factor XIIIa, and chemokine receptor CCR5, whereas LC specifically express Langerin, membrane ATPase (CD39), and CCR6, all hallmarks of the LC lineage. In addition, under steady-state conditions, both DC subsets display a strikingly different activation status, indicative of distinct functional properties. CD1a+ DDC exhibit a more activated, proinflammatory, migratory, and T cell-stimulatory profile, as compared with LC, whereas LC mainly express molecules involved in cell adhesion and DC retention in the epidermis. In conclusion, transcriptional profiling is consistent with the notion that CD1a+ DDC and LC represent two distinct DC subsets but also that under steady-state conditions, CD1a+ DDC and epidermal LC represent opposites of the DC activation spectrum.
The Role of Mineralocorticoid Receptor Expression in Brain Remodeling after Cerebral Ischemia
Authors: Oyamada Naofumi , Sone Masakatsu , Miyashita Kazutoshi , Park Kwijun , Taura Daisuke , Inuzuka Megumi , Sonoyama Takuhiro , Tsujimoto Hirokazu , Fukunaga Yasutomo , Tamura Naohisa , Itoh Hiroshi , Nakao Kazuwa
Published: April 2008

Mineralocorticoid receptors (MRs) are classically known to be expressed in the distal collecting duct of the kidney. Recently it was reported that MR is identified in the heart and vasculature. Although MR expression is also found in the brain, it is restricted to the hippocampus and cerebral cortex under normal condition, and the role played by MRs in brain remodeling after cerebral ischemia remains unclear. In the present study, we used the mouse 20-min middle cerebral artery occlusion model to examine the time course of MR expression and activity in the ischemic brain. We found that MR-positive cells remarkably increased in the ischemic striatum, in which MR expression is not observed under normal conditions, during the acute and, especially, subacute phases after stroke and that the majority of MR-expressing cells were astrocytes that migrated to the ischemic core. Treatment with the MR antagonist spironolactone markedly suppressed superoxide production within the infarct area during this period. Quantitative real-time RT-PCR revealed that spironolactone stimulated the expression of neuroprotective or angiogenic factors, such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), whereas immunohistochemical analysis showed astrocytes to be cells expressing bFGF and VEGF. Thereby the incidence of apoptosis was reduced. The up-regulated bFGF and VEGF expression also appeared to promote endogenous angiogenesis and blood flow within the infarct area and to increase the number of neuroblasts migrating toward the ischemic striatum. By these beneficial effects, the infarct volume was significantly reduced in spironolactone-treated mice. Spironolactone may thus provide therapeutic neuroprotective effects in the ischemic brain after stroke.
Origins of Gonadotropin-Releasing Hormone (GnRH) in Vertebrates: Identification of a Novel GnRH in a Basal Vertebrate, the Sea Lamprey
Authors: Kavanaugh Scott I. , Nozaki Masumi , Sower Stacia A.
Published: April 2008

We cloned a cDNA encoding a novel (GnRH), named lamprey GnRH-II, from the sea lamprey, a basal vertebrate. The deduced amino acid sequence of the newly identified lamprey GnRH-II is QHWSHGWFPG. The architecture of the precursor is similar to that reported for other GnRH precursors consisting of a signal peptide, decapeptide, a downstream processing site, and a GnRH-associated peptide; however, the gene for lamprey GnRH-II does not have introns in comparison with the gene organization for all other vertebrate GnRHs. Lamprey GnRH-II precursor transcript was widely expressed in a variety of tissues. In situ hybridization of the brain showed expression and localization of the transcript in the hypothalamus, medulla, and olfactory regions, whereas immunohistochemistry using a specific antiserum showed only GnRH-II cell bodies and processes in the preoptic nucleus/hypothalamus areas. Lamprey GnRH-II was shown to stimulate the hypothalamic-pituitary axis using in vivo and in vitro studies. Lamprey GnRH-II was also shown to activate the inositol phosphate signaling system in COS-7 cells transiently transfected with the lamprey GnRH receptor. These studies provide evidence for a novel lamprey GnRH that has a role as a third hypothalamic GnRH. In summary, the newly discovered lamprey GnRH-II offers a new paradigm of the origin of the vertebrate GnRH family. We hypothesize that due to a genome/gene duplication event, an ancestral gene gave rise to two lineages of GnRHs: the gnathostome GnRH and lamprey GnRH-II.
Intracardiac septation requires hedgehog-dependent cellular contributions from outside the heart
Authors: Goddeeris Matthew M. , Rho Silvia , Petiet Alexandra , Davenport Chandra L. , Johnson G. Allan , Meyers Erik N. , Klingensmith John
Published: April 2008

Septation of the mammalian heart into four chambers requires the orchestration of multiple tissue progenitors. Abnormalities in this process can result in potentially fatal atrioventricular septation defects (AVSD). The contribution of extracardiac cells to atrial septation has recently been recognized. Here, we use a genetic marker and novel magnetic resonance microscopy techniques to demonstrate the origins of the dorsal mesenchymal protrusion in the dorsal mesocardium, and its substantial contribution to atrioventricular septation. We explore the functional significance of this tissue to atrioventricular septation through study of the previously uncharacterized AVSD phenotype of Shh-/- mutant mouse embryos. We demonstrate that Shh signaling is required within the dorsal mesocardium for its contribution to the atria. Failure of this addition results in severe AVSD. These studies demonstrate that AVSD can result from a primary defect in dorsal mesocardium, providing a new paradigm for the understanding of human AVSD.
Social influence in the theory of planned behaviour: The role of descriptive, injunctive, and in‐group norms
Authors: White Katherine M. , Smith Joanne R. , Terry Deborah J. , Greenslade Jaimi H. , McKimmie Blake M.
Published: April 2008

The present research investigated three approaches to the role of norms in the theory of planned behaviour (TPB). Two studies examined the proposed predictors of intentions to engage in household recycling (Studies 1 and 2) and reported recycling behaviour (Study 1). Study 1 tested the impact of descriptive and injunctive norms (personal and social) and the moderating role of self‐monitoring on norm ‐ intention relations. Study 2 examined the role of group norms and group identification and the moderating role of collective self on norm ‐ intention relations. Both studies demonstrated support for the TPB and the inclusion of additional normative variables: attitudes; perceived behavioural control; descriptive; and personal injunctive norms (but not social injunctive norm) emerged as significant independent predictors of intentions. There was no evidence that the impact of norms on intentions varied as a function of the dispositional variables of self‐monitoring (Study 1) or the collective self (Study 2). There was support, however, for the social identity approach to attitude ‐ behaviour relations in that group norms predicted recycling intentions, particularly for individuals who identified strongly with the group. The results of these two studies highlight the critical role of social influence processes within the TPB and the attitude ‐ behaviour context.
Self‐consciousness, friendship quality, and adolescent internalizing problems
Authors: Bowker Julie C. , Rubin Kenneth H.
Published: April 2008

The correlates between public and private self‐consciousness and internalizing difficulties were examined during early adolescence. Friendship quality was assessed as a possible moderator of the relation between self‐consciousness and maladjustment. One hundred and thirty‐seven young adolescents (N=87 girls; M age=13.98 years) reported on their self‐consciousness, internalizing problems, and the quality of their best friendship. Results indicated stronger associations between private self‐consciousness and internalizing correlates than between public self‐consciousness and internalizing problems, suggesting that private self‐consciousness may be a stronger risk factor during adolescence. Contrary to expectations, evidence revealed that positive friendship quality may exacerbate some difficulties associated with self‐consciousness. Results pertaining to friendship quality add to the growing literature on the ways in which friendships can contribute to adjustment difficulties.
The roles of context and everyday experience in understanding work‐non‐work relationships: A qualitative diary study of white‐ and blue‐collar workers
Authors: Poppleton Sarah , Briner Rob B. , Kiefer Tina
Published: April 2008

The purpose of the study was to address several of the limitations of work‐non‐work research by adopting a qualitative diary methodology which explored insiders' accounts of both the positive and negative aspects of work‐non‐work relationships and examined the role of context in shaping such relationships. Daily diary data on work‐non‐work events and post‐diary interview data were collected from participants in two contrasting organizational contexts: Flexorg (N=20), a progressive local government organization and The Factory (N=18), a traditional manufacturing organization. Work‐non‐work relationships were found to be simultaneously enriching and depleting in both organizations. For Flexorg workers, work‐non‐work relationships were characterized by facilitation and time‐based conflicts. At The Factory, high spillover from work to non‐work and vice versa challenged the assumption that blue‐collar work is typified by segmentation (Nippert‐Eng, 1995). The experience of work‐non‐work events was shaped by the nature of the work, the work‐non‐work culture and working patterns in both organizations. The study also identified negative spillover as a qualitatively more important problem than work‐non‐work conflict in this study, and identified a social dimension of work‐non‐work conflict which was found across organizational contexts.
Transitioning between temporary and permanent employment: A two‐wave study on the entrapment, the stepping stone and the selection hypothesis
Authors: De Cuyper Nele , Notelaers Guy , De Witte Hans
Published: April 2008

The present two‐wave study investigates how transitioning between temporary and permanent employment relates to a number of psychological consequences; namely, work engagement, affective organizational commitment, life satisfaction, and turnover intention. We hypothesize that temporary employment associates with unfavourable outcomes when it is a trap (entrapment hypothesis), while no such unfavourable outcomes are expected for those who transition to permanent employment (stepping stone hypothesis). Furthermore, we investigate the assumption that transitioning from permanent to temporary employment relates to unfavourable outcomes. Finally, we investigate dynamics related to selection into temporary or permanent employment. Hypotheses are tested on a sample of 1,475 workers. The results show that continuous temporary employment does not relate to unfavourable outcomes over time, while gaining permanent employment associates with increased work engagement. Also, permanent workers who transition to temporary employment are more engaged and committed after transitioning. No evidence for possible selection mechanisms is found.
Deliberate practice among South African small business owners: Relationships with education, cognitive ability, knowledge, and success
Authors: Unger Jens M. , Keith Nina , Hilling Christine , Gielnik Michael M. , Frese Michael
Published: April 2008

The study examines antecedents and outcomes of deliberate practice activities in South African small businesses. Deliberate practice consists of individualized self‐regulated and effortful activities aimed at improving one's current performance level. Interview and questionnaire data from 90 South African business owners showed a direct impact of deliberate practice on entrepreneurial knowledge as well as an indirect effect on business growth via entrepreneurial knowledge. Cognitive ability and education were identified as antecedents of deliberate practice. Findings underline the importance of continuous proactive learning efforts in small business. The results of this study are relevant for policy makers, consultants, and credit providers.
Illness and treatment cognitions and health related quality of life in end stage renal disease
Authors: Griva Konstadina , Jayasena Dakshina , Davenport Andrew , Harrison Michael , Newman Stanton P.
Published: April 2008

Objectives. Patients' beliefs regarding illness and treatment are important to understand responses to chronic disease. The present study aimed (i) to assess the illness representations and treatment disruption beliefs of patients with end stage renal disease (ESRD), (ii) to determine whether beliefs about illness and treatment differ between different renal replacement therapies, and (iii) to examine whether these beliefs are associated with health related quality of life (HQoL).

Method. A cross‐sectional sample of 262 ESRD patients, 145 dialysis and 117 kidney transplant recipients completed the illness perceptions questionnaire, the illness effects questionnaire, the treatment effects questionnaire and the short form 36 health survey. Measures of ESRD severity/co‐morbidity and biochemistry were also collected.

Results. HQoL levels were higher in transplant patients. Dialysis patients reported more symptoms associated with ESRD (p<.001), stronger chronic timeline beliefs (p<.001), lower control beliefs (p<.05), and more illness and treatment disruptiveness (ps<.01). Illness and treatment disruptiveness, consequences and identity were inversely associated with HQoL whereas control was positively associated with HQoL. Multiple regressions indicated that treatment and illness disruptiveness, identity and consequences beliefs accounted for 22.9–67.6% of the variance HQoL although specific multivariate correlates differed across physical and emotional HQoL and between dialysis and transplantation.

Conclusions. The beliefs that patients hold about their illness and treatment appear to be related to the type renal replacement therapy being undertaken. These cognitions have associations with HQoL in dialysis and transplantation that are independent of those of socio‐demographic and clinical factors.
Cognitive and social processes predicting partner psychological adaptation to early stage breast cancer
Authors: Manne Sharon , Ostroff Jamie , Fox Kevin , Grana Generosa , Winkel Gary
Published: April 2008

Introduction. The diagnosis and subsequent treatment for early stage breast cancer is stressful for partners. Little is known about the role of cognitive and social processes predicting the longitudinal course of partners' psychosocial adaptation. This study evaluated the role of cognitive and social processing in partner psychological adaptation to early stage breast cancer, evaluating both main and moderator effect models. Moderating effects for meaning making, acceptance, and positive reappraisal on the predictive association of searching for meaning, emotional processing, and emotional expression on partner psychological distress were examined.

Materials and methods. Partners of women diagnosed with early stage breast cancer were evaluated shortly after the ill partner's diagnosis (N=253), 9 (N=167), and 18 months (N=149) later. Partners completed measures of emotional expression, emotional processing, acceptance, meaning making, and general and cancer‐specific distress at all time points.

Results. Lower satisfaction with partner support predicted greater global distress, and greater use of positive reappraisal was associated with greater distress. The predicted moderator effects for found meaning on the associations between the search for meaning and cancer‐specific distress were found and similar moderating effects for positive reappraisal on the associations between emotional expression and global distress and for acceptance on the association between emotional processing and cancer‐specific distress were found.

Conclusions. Results indicate several cognitive–social processes directly predict partner distress. However, moderator effect models in which the effects of partners' processing depends upon whether these efforts result in changes in perceptions of the cancer experience may add to the understanding of partners' adaptation to cancer.
The relationship of treatment preferences and experiences to outcome in generalized anxiety disorder (GAD)
Authors: Berg Adrienne Levy. , Sandahl Christer. , Clinton David.
Published: April 2008

Objectives. The relationship of treatment preferences and experiences to outcome was explored in patients with generalized anxiety disorder (GAD).

Design. Patients were randomly allocated to either affect‐focused body psychotherapy (ABP) (N=26) or standard psychiatric out‐patient treatment (N=17).

Method. Initial preferences and subsequent experiences of treatment interventions were measured using a questionnaire focusing on support, inward reflection, concrete and directive problem solving, and affective expression. Outcome was assessed after 1 and 2 years in relation to symptom change.

Results. ABP patients reported being helped by supportive and reflective treatment interventions to a greater extent than controls. ABP patients also had more positive experiences of supportive and emotionally expressive interventions than they had expected at initial assessment. When patients were divided into two groups on the basis of patterns of preferences and experiences using cluster analysis, it was found that differences in outcome were considerably more marked for clusters than treatment groups.

Conclusions. It is concluded that treatment preferences may have considerable interpersonal potential in therapy; how therapists utilize this potential may be important for improving outcome.