bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Level of Pain Acceptance Differentially Related to Social Cognitions and Behavior? The Case of Active Women with Arthritis
Authors: Gyurcsik Nancy C. , Brawley Lawrence R. , Spink Kevin S. , Glazebrook Karen E. , Anderson Tara J.
Published: January 2011

Pain from arthritis is a barrier to physical activity (PA), yet some people still manage to be active. This study examined whether women with greater or weaker arthritis pain acceptance were distinguished by social cognitions (self-regulatory efficacy to overcome barriers; outcome expectations of PA) and whether PA differences existed. Women with arthritis ( N = 118) completed two surveys. After controlling for pain, a hierarchical discriminant function analysis discriminated pain acceptance groups in terms of the social cognitions. Greater pain acceptance participants were also significantly more active. Findings contribute new insight on the combination of a disease-related factor (pain acceptance) and social cognitions important for adherence.
Health Care Reform and the Federal Transformation Initiatives: Capitalizing on the Potential of Advanced Practice Psychiatric Nurses
Authors: Hanrahan Nancy P. , Delaney Kathleen , Merwin Elizabeth
Published: January 2011

In the last decade the US federal government proposed a transformation vision of mental health service delivery; patient-centered, evidence-based and recovery oriented treatment models. Health care reform brings additional expectations for innovation in mental/substance use service delivery, particularly the idea of creating systems where physical health, mental health and substance use treatment is fully integrated. Psychiatric nurses, as one of the four core US mental health professions, have the potential to play a significant role in the both the transformation initiative and health care reform vision. However, psychiatric nurses, particularly advanced practice psychiatric nurses, are an untapped resource due in part to significant state regulatory barriers that limit their scope of practice in many states. The purpose of this paper is to document what is currently known about advanced practice psychiatric nurses and discuss policy implications for tapping into the strengths of this workforce. Strategies for facilitating utilization of advanced practice psychiatric nurses discussed.
Genetic and Environmental Influences in Delinquent Peer Affiliation: From the Peer Network Approach
Authors: Yun Ilhong , Cheong Jinseong , Walsh Anthony
Published: January 2011

Mainstream criminologists have long maintained that delinquent peer group formation is largely a function of family—environmental variables and have ignored self-selection into peer groups because of genetic proclivities. A small number of recent studies, however, suggest that genes are implicated in delinquent peer affiliation. Given the potentially far-reaching implication of such research findings, the authors replicate Beaver, Wright, and DeLisi’s (2008) study, among others, using a direct measure of peer delinquency. That is, the authors analyze the Add Health genetic data employing a measure of peer delinquency which is based on the delinquency counts reported by peers themselves rather than respondents’ self-reports. Even employing this alternative measure, their results clearly support the original study, providing further evidence of genetic underpinnings of delinquent peer group formation.
Novel imatinib-sensitive PDGFRA-activating point mutations in hypereosinophilic syndrome induce growth factor independence and leukemia-like disease
Authors: Elling Christian , Erben Philipp , Walz Christoph , Frickenhaus Marie , Schemionek Mirle , Stehling Martin , Serve Hubert , Cross Nicholas C. P. , Hochhaus Andreas , Hofmann Wolf-Karsten , Berdel Wolfgang E. , Müller-Tidow Carsten , Reiter Andreas , Koschmieder Steffen
Published: January 2011

The FIP1L1-PDGFRA fusion is seen in a fraction of cases with a presumptive diagnosis of hypereosinophilic syndrome (HES). However, because most HES patients lack FIP1L1-PDGFRA, we studied whether they harbor activating mutations of the PDGFRA gene. Sequencing of 87 FIP1L1-PDGFRA–negative HES patients revealed several novel PDGFRA point mutations (R481G, L507P, I562M, H570R, H650Q, N659S, L705P, R748G, and Y849S). When cloned into 32D cells, N659S and Y849S and—on selection for high expressors—also H650Q and R748G mutants induced growth factor–independent proliferation, clonogenic growth, and constitutive phosphorylation of PDGFRA and Stat5. Imatinib antagonized Stat5 phosphorylation. Mutations involving positions 659 and 849 had been shown previously to possess transforming potential in gastrointestinal stromal tumors. Because H650Q and R748G mutants possessed only weak transforming activity, we injected 32D cells harboring these mutants or FIP1L1-PDGFRA into mice and found that they induced a leukemia-like disease. Oral imatinib treatment significantly decreased leukemic growth in vivo and prolonged survival. In conclusion, our data provide evidence that imatinib-sensitive PDGFRA point mutations play an important role in the pathogenesis of HES and we propose that more research should be performed to further define the frequency and treatment response of PDGFRA mutations in FIP1L1-PDGFRA–negative HES patients.
A novel role for platelet secretion in angiogenesis: mediating bone marrow–derived cell mobilization and homing
Authors: Feng Weiyi , Madajka Maria , Kerr Bethany A. , Mahabeleshwar Ganapati H. , Whiteheart Sidney W. , Byzova Tatiana V.
Published: January 2011

Angiogenesis alleviates hypoxic stress in ischemic tissues or during tumor progression. In addition to endothelial cell proliferation and migration, the angiogenic process requires bone marrow–derived cell (BMDC) recruitment to sites of neovascularization. However, the mechanism of communication between hypoxic tissues and the BM remains unknown. Using 2 models of hypoxia-induced angiogenesis (ischemic hindlimb surgery and subcutaneous tumor growth), we show that platelet infusion promotes BMDC mobilization into the circulation, BMDC recruitment into growing neovasculature, tumor vascularization, and blood flow restoration in ischemic limbs, whereas platelet depletion inhibits these effects. Thus, platelets are required for BMDC recruitment into ischemia-induced vasculature. Secretion of platelet α-granules, but neither dense granules nor platelet aggregation is crucial for BMDC homing and subsequent angiogenesis, as determined using VAMP-8−/−, Pearl, and integrin Beta 3−/− platelets. Finally, platelets sequester tumor-derived promoters of angiogenesis and BMDC mobilization, which are counterbalanced by the antiangiogenic factor thrombospondin-1. A lack of thrombospondin-1 in platelets leads to an imbalance in proangiogenic and antiangiogenic factors and accelerates tumor growth and vascularization. Our data demonstrate that platelets stimulate BMDC homing in a VAMP-8–dependent manner, revealing a previously unknown role for platelets as key mediators between hypoxic tissues and the bone marrow during angiogenesis.
G-CSF–mediated thrombopoietin release triggers neutrophil motility and mobilization from bone marrow via induction of Cxcr2 ligands
Authors: Köhler Anja , De Filippo Katia , Hasenberg Mike , van den Brandt Cindy , Nye Emma , Hosking Martin P. , Lane Thomas E. , Männ Linda , Ransohoff Richard M. , Hauser Anja E. , Winter Oliver , Schraven Burkhart , Geiger Hartmut , Hogg Nancy , Gunzer Matthias
Published: January 2011

Emergency mobilization of neutrophil granulocytes (neutrophils) from the bone marrow (BM) is a key event of early cellular immunity. The hematopoietic cytokine granulocyte-colony stimulating factor (G-CSF) stimulates this process, but it is unknown how individual neutrophils respond in situ. We show by intravital 2-photon microscopy that a systemic dose of human clinical-grade G-CSF rapidly induces the motility and entry of neutrophils into blood vessels within the tibial BM of mice. Simultaneously, the neutrophil-attracting chemokine KC (Cxcl1) spikes in the blood. In mice lacking the KC receptor Cxcr2, G-CSF fails to mobilize neutrophils and antibody blockade of Cxcr2 inhibits the mobilization and induction of neutrophil motility in the BM. KC is expressed by megakaryocytes and endothelial cells in situ and is released in vitro by megakaryocytes isolated directly from BM. This production of KC is strongly increased by thrombopoietin (TPO). Systemic G-CSF rapidly induces the increased production of TPO in BM. Accordingly, a single injection of TPO mobilizes neutrophils with kinetics similar to G-CSF, and mice lacking the TPO receptor show impaired neutrophil mobilization after short-term G-CSF administration. Thus, a network of signaling molecules, chemokines, and cells controls neutrophil release from the BM, and their mobilization involves rapidly induced Cxcr2-mediated motility controlled by TPO as a pacemaker.
Interactions between factor XIII and the αC region of fibrinogen
Authors: Smith Kerrie A. , Adamson Penelope J. , Pease Richard J. , Brown Jane M. , Balmforth Anthony J. , Cordell Paul A. , Ariëns Robert A. S. , Philippou Helen , Grant Peter J.
Published: January 2011

Fibrinogen αC residues 242-424 have been shown to have a major regulatory role in the activation of factor XIII-A2B2 (FXIII-A2B2); however, the interactions underpinning this enhancing effect have not been determined. Here, we have characterized the binding of recombinant (r)FXIII-A subunit and FXIII-A2B2 with fibrin(ogen) and fibrin αC residues 233-425. Using recombinant truncations of the fibrin αC region 233-425 and surface plasmon resonance, we found that activated rFXIII-A bound αC 233-425 (Kd of 2.35 ± 0.09μM) which was further localized to αC 389-403. Site-directed mutagenesis of this region highlighted Glu396 as a key residue for binding of activated rFXIII-A. The interaction was specific for activated rFXIII-A and depended on the calcium-induced conformational change known to occur in rFXIII-A during activation. Furthermore, nonactivated FXIII-A2B2, thrombin-cleaved FXIII-A2B2, and activated FXIII-A2B2 each bound fibrin(ogen) and specifically αC region 371-425 with high affinity (Kd < 35nM and Kd < 31nM, respectively), showing for the first time the potential involvement of the αC region in binding to FXIII-A2B2. These results suggest that in addition to fibrinogen γ′ chain binding, the fibrin αC region also provides a platform for the binding of FXIII-A2B2 and FXIII-A subunit.
Mixed-phenotype acute leukemia: clinical and laboratory features and outcome in 100 patients defined according to the WHO 2008 classification
Authors: Matutes Estella , Pickl Winfried F. , van't Veer Mars , Morilla Ricardo , Swansbury John , Strobl Herbert , Attarbaschi Andishe , Hopfinger Georg , Ashley Sue , Bene Marie Christine , Porwit Anna , Orfao Alberto , Lemez Petr , Schabath Richard , Ludwig Wolf-Dieter
Published: January 2011

The features of 100 mixed-phenotype acute leukemias (MPALs), fulfilling WHO 2008 criteria, are documented. Myeloid and T-lineage features were demonstrated by cytoplasmic myeloperoxidase and CD3; B-lineage features were demonstrated by at least 2 B-lymphoid markers. There were 62 men and 38 women; 68% were adults. Morphology was consistent with acute lymphoblastic leukemia (ALL; 43%), acute myeloid leukemia (AML; 42%), or inconclusive (15%). Immunophenotyping disclosed B + myeloid (59%), T + myeloid (35%), B + T (4%), or trilineage (2%) combinations. Cytogenetics evidenced t(9;22)/(Ph+) (20%), 11q23/MLL rearrangements (8%), complex (32%), aberrant (27%), or normal (13%) karyotypes. There was no correlation between age, morphology, immunophenotype, or cytogenetics. Response to treatment and outcome were available for 67 and 70 patients, respectively; 27 received ALL, 34 AML, 5 a combination of ALL + AML therapy, and 1 imatinib. ALL treatment induced a response in 85%, AML therapy in 41%; 3 of 5 patients responded to the combination therapy. Forty (58%) patients died, 33 of resistant disease. Overall median survival was 18 months and 37% of patients are alive at 5 years. Age, Ph+, and AML therapy were predictors for poor outcome (P < .001; P = .002; P = .003). MPAL is confirmed to be a poor-risk disease. Adults and Ph+ patients should be considered for transplantation in first remission.
Stringent requirement of a proper level of canonical WNT signalling activity for head formation in mouse embryo
Authors: Fossat Nicolas , Jones Vanessa , Khoo Poh-Lynn , Bogani Debora , Hardy Andrea , Steiner Kirsten , Mukhopadhyay Mahua , Westphal Heiner , Nolan Patrick M. , Arkell Ruth , Tam Patrick P. L.
Published: January 2011

In mouse embryos, loss of Dickkopf-1 (DKK1) activity is associated with an ectopic activation of WNT signalling responses in the precursors of the craniofacial structures and leads to a complete truncation of the head at early organogenesis. Here, we show that ENU-induced mutations of genes coding for two WNT canonical pathway factors, the co-receptor LRP6 and the transcriptional co-activator β-catenin, also elicit an ectopic signalling response and result in loss of the rostral tissues of the forebrain. Compound mutant embryos harbouring combinations of mutant alleles of Lrp6, Ctnnb1 and Dkk1 recapitulate the partial to complete head truncation phenotype of individual homozygous mutants. The demonstration of a synergistic interaction of Dkk1, Lrp6 and Ctnnb1 provides compelling evidence supporting the concepts that (1) stringent regulation of the level of canonical WNT signalling is necessary for head formation, (2) activity of the canonical pathway is sufficient to account for the phenotypic effects of mutations in three different components of the signal cascade and (3) rostral parts of the brain and the head are differentially more sensitive to canonical WNT signalling and their development is contingent on negative modulation of WNT signalling activity.
Integrin α5β1 facilitates cancer cell invasion through enhanced contractile forces
Authors: Mierke Claudia Tanja , Frey Benjamin , Fellner Martina , Herrmann Martin , Fabry Ben
Published: January 2011

Cell migration through connective tissue, or cell invasion, is a fundamental biomechanical process during metastasis formation. Cell invasion usually requires cell adhesion to the extracellular matrix through integrins. In some tumors, increased integrin expression is associated with increased malignancy and metastasis formation. Here, we have studied the invasion of cancer cells with different α5β1 integrin expression levels into loose and dense 3D collagen fiber matrices. Using a cell sorter, we isolated from parental MDA-MB-231 breast cancer cells two subcell lines expressing either high or low amounts of α5β1 integrins (α5β1high or α5β1low cells, respectively). α5β1high cells showed threefold increased cell invasiveness compared to α5β1low cells. Similar results were obtained for 786-O kidney and T24 bladder carcinoma cells, and cells in which the α5 integrin subunit was knocked down using specific siRNA. Knockdown of the collagen receptor integrin subunit α2 also reduced invasiveness, but to a lesser degree than knockdown of integrin subunit α5. Fourier transform traction microscopy revealed that the α5β1high cells generated sevenfold greater contractile forces than α5β1low cells. Cell invasiveness was reduced after addition of the myosin light chain kinase inhibitor ML-7 in α5β1high cells, but not in α5β1low cells, suggesting that α5β1 integrins enhance cell invasion through enhanced transmission and generation of contractile forces.
Dynamic recruitment of licensing factor Cdt1 to sites of DNA damage
Authors: Roukos Vassilis , Kinkhabwala Ali , Colombelli Julien , Kotsantis Panagiotis , Taraviras Stavros , Nishitani Hideo , Stelzer Ernst , Bastiaens Philippe , Lygerou Zoi
Published: January 2011

For genomic integrity to be maintained, the cell cycle and DNA damage responses must be linked. Cdt1, a G1-specific cell-cycle factor, is targeted for proteolysis by the Cul4-Ddb1Cdt2 ubiquitin ligase following DNA damage. Using a laser nanosurgery microscope to generate spatially restricted DNA damage within the living cell nucleus, we show that Cdt1 is recruited onto damaged sites in G1 phase cells, within seconds of DNA damage induction. PCNA, Cdt2, Cul4, DDB1 and p21Cip1 also accumulate rapidly to damaged sites. Cdt1 recruitment is PCNA-dependent, whereas PCNA and Cdt2 recruitment are independent of Cdt1. Fitting of fluorescence recovery after photobleaching profiles to an analytic reaction-diffusion model shows that Cdt1 and p21Cip1 exhibit highly dynamic binding at the site of damage, whereas PCNA appears immobile. Cdt2 exhibits both a rapidly exchanging and an apparently immobile subpopulation. Our data suggest that PCNA provides an immobile binding interface for dynamic Cdt1 interactions at the site of damage, which leads to rapid Cdt1 recruitment to damaged DNA, preceding Cdt1 degradation.
The human NKG2D ligand ULBP2 can be expressed at the cell surface with or without a GPI anchor and both forms can activate NK cells
Authors: Fernández-Messina Lola , Ashiru Omodele , Agüera-González Sonia , Reyburn Hugh T. , Valés-Gómez Mar
Published: January 2011

The activating immune receptor NKG2D binds to several stress-induced ligands that are structurally different. MHC-class-I-related chain (MIC) A/B molecules have a transmembrane domain, whereas most UL16 binding proteins (ULBPs) are glycosylphosphatidylinositol (GPI)-linked molecules. The significance of this variability in membrane anchors is unclear. Here, we demonstrate that ULBP2, but not ULBP1 or ULBP3, can reach the cell surface without the GPI modification. Several proteins are expressed at the cell surface as both transmembrane and GPI-linked molecules, either via alternative splicing or by the expression of linked genes. However, to our knowledge, ULBP2 is the first single mammalian cDNA that can be expressed as either a transmembrane or a GPI-anchored protein. The rate of maturation and the levels of cell surface expression of the non-GPI-linked form were lower than those of the GPI-linked ULBP2. Nonetheless, non-GPI ULBP2 was recognised by NKG2D and triggered NK cell cytotoxicity. These data show that differences in membrane attachment by NKG2D ligands are more important for regulation of their surface expression than for cytotoxic recognition by NKG2D and emphasise that detailed characterisation of the cell biology of individual NKG2D ligands will be necessary to allow targeted modulation of this system.
Serine/threonine protein kinase SGK1 in glucocorticoid-dependent transdifferentiation of pancreatic acinar cells to hepatocytes
Authors: Wallace Karen , Long Quan , Fairhall Emma A. , Charlton Keith A. , Wright Matthew C.
Published: January 2011

Elevated glucocorticoid levels result in the transdifferentiation of pancreatic acinar cells into hepatocytes through a process that requires a transient repression of WNT signalling upstream of the induction of C/EBP-β. However, the mechanism by which glucocorticoid interacts with WNT signalling is unknown. A screen of microarray data showed that the serine/threonine protein kinase SGK1 (serum- and glucocorticoid-regulated kinase 1) was markedly induced in the model B-13 pancreatic rat acinar cell line after glucocorticoid treatment (which converts them into hepatocyte-like ‘B-13/H’ cells) and this was confirmed at the level of mRNA (notably an alternatively transcribed SGK1C form) and protein. Knockdown of SGK1 using an siRNA designed to target all variant transcripts inhibited glucocorticoid-dependent transdifferentiation, whereas overexpression of the human C isoform (and also the human SGK1F isoform, for which no orthologue in the rat has been identified) alone – but not the wild-type A form – inhibited distal WNT signalling Tcf/Lef transcription factor activity, and converted B-13 cells into B-13/H cells. These effects were lost when the kinase functions of SGK1C and SGK1F were mutated. Inhibition of SGK1 kinase activity also inhibited glucocorticoid-dependent transdifferentiation. Expression of SGK1C and SGK1F resulted in the appearance of phosphorylated β-catenin, and recombinant SGK1 was shown to directly phosphorylate purified β-catenin in vitro in an ATP-dependent reaction. These data therefore demonstrate a crucial role for SGK1 induction in B-13 cell transdifferentiation to B-13/H hepatocytes and suggest that direct phosphorylation of β-catenin by SGK1C represents the mechanism of crosstalk between glucocorticoid and WNT signalling pathways.
Flexible mechanisms: the diverse roles of biological springs in vertebrate movement
Authors: Roberts Thomas J. , Azizi Emanuel
Published: January 2011

The muscles that power vertebrate locomotion are associated with springy tissues, both within muscle and in connective tissue elements such as tendons. These springs share in common the same simple action: they stretch and store elastic strain energy when force is applied to them and recoil to release energy when force decays. Although this elastic action is simple, it serves a diverse set of functions, including metabolic energy conservation, amplification of muscle power output, attenuation of muscle power input, and rapid mechanical feedback that may aid in stability. In recent years, our understanding of the mechanisms and importance of biological springs in locomotion has advanced significantly, and it has been demonstrated that elastic mechanisms are essential for the effective function of the muscle motors that power movement. Here, we review some recent advances in our understanding of elastic mechanisms, with an emphasis on two proposed organizing principles. First, we review the evidence that the various functions of biological springs allow the locomotor system to operate beyond the bounds of intrinsic muscle properties, including metabolic and mechanical characteristics, as well as motor control processes. Second, we propose that an energy-based framework is useful for interpreting the diverse functions of series-elastic springs. In this framework, the direction and timing of the flow of energy between the body, the elastic element and the contracting muscle determine the function served by the elastic mechanism (e.g. energy conservation vs power amplification). We also review recent work demonstrating that structures such as tendons remodel more actively and behave more dynamically than previously assumed.
Effects of grade and mass distribution on the mechanics of trotting in dogs
Authors: Lee David V.
Published: January 2011

Quadrupedal running on grades requires balancing of pitch moments about the center of mass (COM) while supplying sufficient impulse to maintain a steady uphill or downhill velocity. Here, trotting mechanics on a 15 deg grade were characterized by the distribution of impulse between the limbs and the angle of resultant impulse at each limb. Anterior–posterior manipulation of COM position has previously been shown to influence limb mechanics during level trotting of dogs; hence, the combined effects of grade and COM manipulations were explored by adding 10% body mass at the COM, shoulder or pelvis. Whole body and individual limb ground reaction forces, as well as spatiotemporal step parameters, were measured during downhill and uphill trotting. Deviations from steady-speed locomotion were determined by the net impulse angle and accounted for in the statistical model. The limbs exerted only propulsive force during uphill trotting and, with the exception of slight hindlimb propulsion in late stance, only braking force during downhill trotting. Ratios of forelimb impulse to total impulse were computed for normal and shear components. Normal impulse ratios were more different from level values during uphill than downhill trotting, indicating that the limbs act more as levers on the incline. Differential limb function was evident in the extreme divergence of forelimb and hindlimb impulse angles, amplifying forelimb braking and hindlimb propulsive biases observed during level trotting. In both downhill and uphill trotting, added mass at the up-slope limb resulted in fore–hind distributions of normal impulse more similar to those of level trotting and more equal fore–hind distributions of shear impulse. The latter result suggests a functional trade-off in quadruped design: a COM closer to the hindlimbs would distribute downhill braking more equally, whereas a COM closer to the forelimbs would distribute uphill propulsion more equally. Because muscles exert less force when actively shortening than when lengthening, it would be advantageous for the forelimb and hindlimb muscles to share the propulsive burden more equally during uphill trotting. This functional advantage is consistent with the anterior COM position of most terrestrial quadrupeds.
Identification of the elusive peptidergic diuretic hormone in the blood-feeding bugRhodnius prolixus: a CRF-related peptide
Authors: Te Brugge Victoria , Paluzzi Jean-Paul , Schooley David A. , Orchard Ian
Published: January 2011

Probing of a host and ingestion of a blood-meal in a fifth instar Rhodnius prolixus results in a cascade of tightly integrated events. The huge blood-meal is pumped into the anterior midgut during feeding, then modified by diuresis and stored until it is digested. While serotonin is known to be a diuretic hormone in R. prolixus, a peptidergic factor(s) was also known to play a role in diuresis. In the present study we employed molecular techniques and mass spectrometry to determine the sequence of a native CRF-like peptide from R. prolixus (Rhopr DH). In addition, we confirmed the distribution and localization of Rhopr DH using in situ hybridization and immunohistochemistry, and demonstrated its potent biological activity on both the anterior midgut and Malpighian tubules.
Aerodynamic effects of corrugation in flapping insect wings in hovering flight
Authors: Meng Xue Guang , Xu Lei , Sun Mao
Published: January 2011

We have examined the aerodynamic effects of corrugation in model insect wings that closely mimic the wing movements of hovering insects. Computational fluid dynamics were used with Reynolds numbers ranging from 35 to 3400, stroke amplitudes from 70 to 180 deg and mid-stroke angles of incidence from 15 to 60 deg. Various corrugated wing models were tested (care was taken to ensure that the corrugation introduced zero camber). The main results are as follows. At typical mid-stroke angles of incidence of hovering insects (35–50 deg), the time courses of the lift, drag, pitching moment and aerodynamic power coefficients of the corrugated wings are very close to those of the flat-plate wing, and compared with the flat-plate wing, the corrugation changes (decreases) the mean lift by less than 5% and has almost no effect on the mean drag, the location of the center of pressure and the aerodynamic power required. A possible reason for the small aerodynamic effects of wing corrugation is that the wing operates at a large angle of incidence and the flow is separated: the large angle of incidence dominates the corrugation in determining the flow around the wing, and for separated flow, the flow is much less sensitive to wing shape variation. The present results show that for hovering insects, using a flat-plate wing to model the corrugated wing is a good approximation.
Spectral sensitivity of the concave mirror eyes of scallops: potential influences of habitat, self-screening and longitudinal chromatic aberration
Authors: Speiser Daniel I. , Loew Ellis R. , Johnsen Sönke
Published: January 2011

Scallop eyes contain two retinas, one proximal and one distal. Molecular evidence suggests that each retina expresses a different visual pigment. To test whether these retinas have different spectral sensitivities, we used microspectrophotometry to measure the absorption spectra of photoreceptors from the eyes of two different scallop species. Photoreceptors from the proximal and distal retinas of the sea scallop Placopecten magellanicus had absorption peak wavelengths (λmax) of 488±1 nm (mean ± s.e.m.; N=20) and 513±3 nm (N=26), respectively. Photoreceptors from the corresponding retinas of the bay scallop Argopecten irradians had λmax values of 506±1 nm (N=21) and 535±3 nm (N=14). Assuming that the proximal and distal receptors had equal absorption coefficients (kD=0.0067 μm–1), we found that self-screening within the scallop eye caused the proximal and distal receptors in P. magellanicus to have peak absorption at 490 and 520 nm, respectively, and the corresponding receptors in A. irradians to have peak absorption at 504 and 549 nm. We conclude that environment may influence the λmax of scallop visual pigments: P. magellanicus, generally found in blue oceanic water, has visual pigments that are maximally sensitive to shorter wavelengths than those found in A. irradians, which lives in greener inshore water. Scallop distal retinas may be sensitive to longer wavelengths of light than scallop proximal retinas to correct for either self-screening by the retinas or longitudinal chromatic aberration of the lens.
Interactions between detoxification mechanisms and excretion in Malpighian tubules ofDrosophila melanogaster
Authors: Chahine Sarah , O'Donnell Michael J.
Published: January 2011

Insects have long been known to excrete toxins via the Malpighian (renal) tubules. In addition, exposure to natural or synthetic toxins is commonly associated with increases in the activity of detoxification enzymes such as the P450 monoxygenases (P450s) and the glutathione-S-transferases (GSTs). We examined the links between mechanisms for detoxification and excretion in adult Drosophila melanogaster using functional assays and measurements of changes in gene expression by quantitative reverse transcriptase PCR in response to dietary exposure to compounds known to alter activity or gene expression of P450s and GSTs. Dietary exposure to phenol, which alters gene expression for multiple GSTs after seven to 10 generations, was also associated with an increase (more than twofold) in secretion of the organic anion methotrexate (MTX) by isolated tubules. Dietary exposure to the insecticide synergist piperonyl butoxide (PBO) was associated with reduced expression of two P450 genes (Cyp4e2, Cyp4p1) and two GST genes (GstD1, GstD5) in the tubules, as well as increased expression of Cyp12d1 and GstE1. Thin layer chromatographic analysis of fluid secreted by isolated tubules indicated that dietary exposure to PBO resulted in increased levels of an MTX metabolite. In addition, exposure to PBO altered the expression of transporter genes in the tubules, including a Drosophila multidrug resistance-associated protein, and was associated with a 73% increase in MTX secretion by isolated tubules. The results suggest that exposure of Drosophila to toxins evokes a coordinated response by the Malpighian tubules, involving both alterations in detoxification pathways as well as enhanced transport.
Honey bee forager thoracic temperature inside the nest is tuned to broad-scale differences in recruitment motivation
Authors: Sadler Nik , Nieh James C.
Published: January 2011

Insects that regulate flight muscle temperatures serve as crucial pollinators in a broad range of ecosystems, in part because they forage over a wide span of temperatures. Honey bees are a classic example and maintain their thoracic muscles at temperatures (Tth) tuned to the caloric benefits of floral resources. Using infrared thermography, we tested the hypothesis that forager motivation to recruit nestmates for a food source is positively correlated with Tth. We trained bees to a sucrose feeder located 5–100 m from the nest. Recruiting foragers had a significantly higher average Tth (2.7°C higher) when returning from 2.5 mol l–1 sucrose (65% w/w) than when returning from 1.0 mol l–1 sucrose (31% w/w). Foragers exhibited significantly larger thermal fluctuations the longer they spent inside the nest between foraging trips. The difference between maximum and minimum temperatures during a nest visit (Trange) increased with total duration of the nest visit (0.7°C increase per additional min spent inside the nest). Bees that recruited nestmates (waggle or round danced) were significantly warmer, with a 1.4–1.5 times higher ΔTth (difference between Tth and nest ambient air temperature) than bees who tremble danced or simply walked on the nest floor without recruiting between foraging bouts. However, recruiter Tth was not correlated with finer-scale measures of motivation: the number of waggle dance circuits or waggle dance return phase duration. These results support the hypothesis that forager Tth within the nest is correlated to broad-scale differences in foraging motivation.
Aerodynamics of gliding flight in common swifts
Authors: Henningsson P. , Hedenström A.
Published: January 2011

Gliding flight performance and wake topology of a common swift (Apus apus L.) were examined in a wind tunnel at speeds between 7 and 11 m s–1. The tunnel was tilted to simulate descending flight at different sink speeds. The swift varied its wingspan, wing area and tail span over the speed range. Wingspan decreased linearly with speed, whereas tail span decreased in a nonlinear manner. For each airspeed, the minimum glide angle was found. The corresponding sink speeds showed a curvilinear relationship with airspeed, with a minimum sink speed at 8.1 m s–1 and a speed of best glide at 9.4 m s–1. Lift-to-drag ratio was calculated for each airspeed and tilt angle combinations and the maximum for each speed showed a curvilinear relationship with airspeed, with a maximum of 12.5 at an airspeed of 9.5 m s–1. Wake was sampled in the transverse plane using stereo digital particle image velocimetry (DPIV). The main structures of the wake were a pair of trailing wingtip vortices and a pair of trailing tail vortices. Circulation of these was measured and a model was constructed that showed good weight support. Parasite drag was estimated from the wake defect measured in the wake behind the body. Parasite drag coefficient ranged from 0.30 to 0.22 over the range of airspeeds. Induced drag was calculated and used to estimate profile drag coefficient, which was found to be in the same range as that previously measured on a Harris' hawk.
Schlieren Visualization of Shock Wave Phenomena over a Missile-Shaped Body at Hypersonic Mach Numbers
Authors: Saravanan S , Nagashetty K , Hegde G M , Jagadeesh G , Reddy K P J
Published: January 2011

The flow over a missile-shaped configuration is investigated by means of Schlieren visualization in short-duration facility producing free stream Mach numbers of 5.75 and 8. This visualization technique is demonstrated with a 41° full apex angle blunt cone missile-shaped body mounted with and without cavity. Experiments are carried out with air as the test gas to visualize the flow field. The experimental results show a strong intensity variation in the deflection of light in a flow field, due to the flow compressibility. Shock stand-off distance measured with the Schlieren method is in good agreement with theory and computational fluid dynamic study for both the configurations. Magnitude of the shock oscillation for a cavity model may be greater than the case of a model without cavity. The picture of visualization shows that there is an outgoing and incoming flow closer to the cavity. Cavity flow oscillation was found to subside to steady flow with a decrease in the free stream Mach number.
An evaluation of telehealth websites for design, literacy, information and content
Authors: Whitten Pamela , Holtz Bree , Cornacchione Jennifer , Wirth Christina
Published: January 2011

We examined 62 telehealth websites using four assessment criteria: design, literacy, information and telehealth content. The websites came from the member list of the American Telemedicine Association and the Office for the Advancement of Telehealth and partner sites, and were included if they were currently active and at least three clicks deep. Approximately 130 variables were examined for each website by two independent researchers. The websites reviewed contained most of the design variables (mean 74%, SD 6), but fewer of those relating to literacy (mean 26%, SD 6), website information (mean 35%, SD 16) and telehealth content (mean 37%, SD 18). Only 29% of websites encouraged users to ask about telehealth, and 19% contained information on overcoming telehealth barriers. Nonetheless, 84% promoted awareness of telehealth. All evaluation assessments were significantly correlated with each other except for literacy and information. The present study identified various matters that should be addressed when developing telehealth websites. Although much of this represents simple common sense in website design, our evaluation demonstrates that there is still much room for improvement.
Systematic review of studies on telemonitoring of patients with congestive heart failure: a meta-analysis
Authors: Clarke Malcolm , Shah Anila , Sharma Urvashi
Published: January 2011

We conducted a systematic review of large, well-conducted randomised trials designed to evaluate the effectiveness of telemonitoring on patients with congestive heart failure (CHF). Two people reviewed 125 articles independently and selected 13 articles for final review. These studies concerned 3480 patients. The follow-up period of the studies was 3–15 months. Pooled estimate results showed that there was an overall reduction in all-cause mortality ( P = 0.02). There was no overall reduction in all-cause hospital admission ( P = 0.84), although there was a reduction in CHF hospital admission ( P = 0.0004). There was no reduction in all-cause emergency admission ( P = 0.67). There was no significant difference in length of stay in hospital, medication adherence or cost. Telemonitoring in conjunction with nurse home visiting and specialist unit support can be effective in the clinical management of patients with CHF and help to improve their quality of life.
Modeling Fluid Dynamics and Growth Kinetics in Fluidized Bed Spray Granulation
Authors: Li Zhen , Kind Matthias , Gruenewald Gerald
Published: January 2011

Fluidized bed spray granulation is used to produce spherical granules from suspensions, solutions and melts. Experimental investigations revealed that fluid dynamics in the granulator plays a crucial role, in particular in the jet. The jet causes the particle movement as well as drop propagation and deposition on the particles. In this work the “Two Fluid Model” (TFM) is used to simulate the multiphase fluid dynamics in the fluidized bed. The results of simulations were validated by measuring the particle velocity using Laser Doppler Velocimetry (LDV). From the TFM-simulations with implemented growth mechanisms the growth kinetics is obtained and is used to describe the transient states of various granulation processes by solving the appropriate population balances.
Differential utilization of decapping enzymes in mammalian mRNA decay pathways
Authors: Li You , Song Mangen , Kiledjian Megerditch
Published: January 2011

mRNA decapping is a crucial step in the regulation of mRNA stability and gene expression. Dcp2 is an mRNA decapping enzyme that has been widely studied. We recently reported the presence of a second mammalian cytoplasmic decapping enzyme, Nudt16. Here we address the differential utilization of the two decapping enzymes in specified mRNA decay processes. Using mouse embryonic fibroblast (MEF) cell lines derived from a hypomorphic knockout of the Dcp2 gene with undetectable levels of Dcp2 or MEF cell lines harboring a Nudt16-directed shRNA to generate reduced levels of Nudt16, we demonstrate the distinct roles for Dcp2 and Nudt16 in nonsense-mediated mRNA decay (NMD), decay of ARE-containing mRNA and miRNA-mediated silencing. Our results indicated that NMD preferentially utilizes Dcp2 rather than Nudt16; Dcp2 and Nudt16 are redundant in miRNA-mediated silencing; and Dcp2 and Nudt16 are differentially utilized for ARE-mRNA decay. These data demonstrate that the two distinct decapping enzymes can uniquely function in specific mRNA decay processes in mammalian cells.
Evidence that XRN4, an Arabidopsis homolog of exoribonuclease XRN1, preferentially impacts transcripts with certain sequences or in particular functional categories
Authors: Rymarquis Linda A. , Souret Frederic F. , Green Pamela J.
Published: January 2011

One of the major players controlling RNA decay is the cytoplasmic 5′-to-3′ exoribonuclease, which is conserved among eukaryotic organisms. In Arabidopsis, the 5′-to-3′ exoribonuclease XRN4 is involved in disease resistance, the response to ethylene, RNAi, and miRNA-mediated RNA decay. Curiously, XRN4 appears to display selectivity among its substrates because certain 3′ cleavage products formed by miRNA-mediated decay, such as from ARF10 mRNA, accumulate in the xrn4 mutant, whereas others, such as from AGO1, do not. To examine the nature of this selectivity, transcripts that differentially accumulate in xrn4 were identified by combining PARE and Affymetrix arrays. Certain functional categories, such as stamen-associated proteins and hydrolases, were over-represented among transcripts decreased in xrn4, whereas transcripts encoding nuclear-encoded chloroplast-targeted proteins and nucleic acid–binding proteins were over-represented in transcripts increased in xrn4. To ascertain if RNA sequence influences the apparent XRN4 selectivity, a series of chimeric constructs was generated in which the miRNA-complementary sites and different portions of the surrounding sequences from AGO1 and ARF10 were interchanged. Analysis of the resulting transgenic plants revealed that the presence of a 150 nucleotide sequence downstream from the ARF10 miRNA-complementary site conferred strong accumulation of the 3′ cleavage products in xrn4. In addition, sequence analysis of differentially accumulating transcripts led to the identification of 27 hexamer motifs that were over-represented in transcripts or miRNA-cleavage products accumulating in xrn4. Taken together, the data indicate that specific mRNA sequences, like those in ARF10, and mRNAs from select functional categories are attractive targets for XRN4-mediated decay.
Characterization of the B6.61 polymerase ribozyme accessory domain
Authors: Wang Qing S. , Cheng Leslie K.L. , Unrau Peter J.
Published: January 2011

The “RNA world” hypothesis rests on the assumption that RNA polymerase ribozymes can replicate RNA without the use of protein. In the laboratory, in vitro selection has been used to create primitive versions of such polymerases. The best variant to date is a ribozyme called B6.61 that can extend a RNA primer template by 20 nucleotides (nt). This polymerase has two domains: the recently crystallized Class I ligase core, responsible for phosphodiester bond formation, and the poorly characterized accessory domain that makes polymerization possible. Here we find that the accessory domain is specified by a 37-nt bulged stem–loop structure. The accessory domain is positioned by a tertiary interaction between the terminal AL4 loop of the accessory and the J3/4 triloop found within the ligase core. This docking interaction is associated with an unwinding of the A3 and A4 helixes that appear to facilitate the correct positioning of an essential 8-nt purine bulge found between the two helices. This, together with other constraints inferred from tethering the accessory domain to a range of sites on the ligase core, indicates that the accessory domain is draped over the vertex of the ligase core tripod structure. This geometry suggests how the purine bulge in the polymerase replaces the P2 helix in the Class I ligase with a new structure that may facilitate the stabilization of incoming nucleotide triphosphates.
Changes in Self-Reported Attendance of British Adults for Dental Check-Ups between 1991 and 2000
Authors: Batchelor Paul A
Published: January 2011

Objective

To report the changes in self-reported dental check-up patterns of British adults in both the NHS and non-NHS sectors over the period 1991 to 2000.

Method

Longitudinal cross-sectional questionnaire.

Results

Between 1991 and 2000, the annual British Household Panel Survey (BHPS) indicated that there was a steady increase in the percentage of adults who reported having a dental check-up within the previous 12 months, from 53.6% to 62.3%. While the percentage reporting having had a dental check-up under NHS arrangements rose slightly from 44% to 46%, reported non-NHS check-ups rose from 6% to 14%. Variations in reported attendance patterns for check-ups were noted between the sexes and age groups. A higher percentage of females reported having had a dental check-up under NHS arrangements than males, while no differences were found in the non-NHS sector. Those aged between 46–55 years had the highest percentage of dental check-ups (72%) while the lowest was in those aged 66 years or older (43%).

Conclusions

The results of the BHPS indicate that there was an increase in the percentage of British adults attending for a dental check-up within any 12-month period for 1991 to 2000 and that there was considerable variation in attendance by both age and sex.
Folliculotropic T-Cell Lymphocytosis as a Distinct Form of Pilotropic T-Cell Dyscrasia
Authors: Magro Cynthia M. , Crowson A. Neil
Published: January 2011

Cutaneous T-cell dyscrasia represents a heterogeneous group of persistent clonal and usually epitheliotropic T-cell infiltrates with a seemingly low risk for progression to mycosis fungoides (MF). Mucin-poor folliculotropic T-cell lymphocytosis is the least well characterized with only a few anecdotal case reports.

Cases of folliculotropic lymphocytosis were retrieved via a natural language search from 2 dermatopathology databases. Comprehensive light microscopic, phenotypic, and molecular studies were conducted.

There were 12 females and 12 males, with mean age of 41 years. There were 2 main clinical presentations: facial erythematous infiltrative papules and/or nodules vs extremity and truncal solitary, large, scaly plaques. The mean duration of the lesions was 3 years. Progression to follicular MF was noted in 1 case. Migration of small lymphocytes into the superficial portions of the hair follicle unaccompanied by other inflammatory cells or mucin was observed; lymphocytes with a cerebriform appearance could be seen. The CD4/CD8 ratio was more than 5:1 with significant reductions in the expression of CD62L and CD7. Of 20 cases tested, 5 showed monoclonality.

Folliculotropic T-cell lymphocytosis is a form of pilotropic T-cell dyscrasia distinct from MF and alopecia mucinosa; the course seems indolent in most cases.