bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulating the electrostatic guidance of the vectorial translocations in hexameric helicases and translocases
Authors: Liu Hanbin , Shi Yemin , Chen Xiaojiang S. , Warshel Arieh
Published: April 2009

The molecular origin of the action of helicases is explored, starting with a model built based on the different X-ray structures of the large tumor antigen (LTag) hexameric helicase and a simplified model containing the ionized phosphate backbones of a single-strand DNA. The coupling between the protein structural changes and the translocation process is quantified using an effective electrostatic free-energy surface for the protein/DNA complex. This surface is then used in Langevin dynamics simulations of the time dependence of the translocation process. Remarkably, the simulated motion along the free-energy surface results in a vectorial translocation of the DNA, consistent with the biological process. The electrostatic energy of the system appears to reproduce the directionality of this process. Thus, we are able to provide a consistent structure-based molecular description of the energetic and dynamics of the translocation process. This analysis may have general implications for relating structural models to translocation directionality in helicases and other DNA translocases.
Aberrant cleavage of TDP-43 enhances aggregation and cellular toxicity
Authors: Zhang Yong-Jie , Xu Ya-Fei , Cook Casey , Gendron Tania F. , Roettges Paul , Link Christopher D. , Lin Wen-Lang , Tong Jimei , Castanedes-Casey Monica , Ash Peter , Gass Jennifer , Rangachari Vijayaraghavan , Buratti Emanuele , Baralle Francisco , Golde Todd E. , Dickson Dennis W. , Petrucelli Leonard
Published: April 2009

Inclusions of TAR DNA-binding protein-43 (TDP-43), a nuclear protein that regulates transcription and RNA splicing, are the defining histopathological feature of frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-Us) and sporadic and familial forms of amyotrophic lateral sclerosis (ALS). In ALS and FTLD-U, aggregated, ubiquitinated, and N-terminally truncated TDP-43 can be isolated from brain tissue rich in neuronal and glial cytoplasmic inclusions. The loss of TDP-43 function resulting from inappropriate cleavage, translocation from the nucleus, or its sequestration into inclusions could play important roles in neurodegeneration. However, it is not known whether TDP-43 fragments directly mediate toxicity and, more specifically, whether their abnormal aggregation is a cause or consequence of pathogenesis. We report that the ectopic expression of a ≈25-kDa TDP-43 fragment corresponding to the C-terminal truncation product of caspase-cleaved TDP-43 leads to the formation of toxic, insoluble, and ubiquitin- and phospho-positive cytoplasmic inclusions within cells. The 25-kDa C-terminal fragment is more prone to phosphorylation at S409/S410 than full-length TDP-43, but phosphorylation at these sites is not required for inclusion formation or toxicity. Although this fragment shows no biological activity, its exogenous expression neither inhibits the function nor causes the sequestration of full-length nuclear TDP-43, suggesting that the 25-kDa fragment can induce cell death through a toxic gain-of-function. Finally, by generating a conformation-dependent antibody that detects C-terminal fragments, we show that this toxic cleavage product is specific for pathologic inclusions in human TDP-43 proteinopathies.
Fine mapping and functional analysis of a common variant in
MSMB
on chromosome 10q11.2 associated with prostate cancer susceptibility
Authors: Lou Hong , Yeager Meredith , Li Hongchuan , Bosquet Jesus Gonzalez , Hayes Richard B. , Orr Nick , Yu Kai , Hutchinson Amy , Jacobs Kevin B. , Kraft Peter , Wacholder Sholom , Chatterjee Nilanjan , Feigelson Heather Spencer , Thun Michael J. , Diver W. Ryan , Albanes Demetrius , Virtamo Jarmo , Weinstein Stephanie , Ma Jing , Gaziano J. Michael , Stampfer Meir , Schumacher Fredrick R. , Giovannucci Edward , Cancel-Tassin Geraldine , Cussenot Olivier , Valeri Antoine , Andriole Gerald L. , Crawford E. David , Anderson Stephen K. , Tucker Margaret , Hoover Robert N. , Fraumeni Joseph F. , Thomas Gilles , Hunter David J. , Dean Michael , Chanock Stephen J.
Published: April 2009

Two recent genome-wide association studies have independently identified a prostate cancer susceptibility locus on chromosome 10q11.2. The most significant single-nucleotide polymorphism (SNP) marker reported, rs10993994, is 57 bp centromeric of the first exon of the MSMB gene, which encodes β-microseminoprotein (prostatic secretory protein 94). In this study, a fine-mapping analysis using HapMap SNPs was conducted across a ≈65-kb region (chr10: 51168330–51234020) flanking rs10993994 with 13 tag SNPs in 6,118 prostate cancer cases and 6,105 controls of European origin from the Cancer Genetic Markers of Susceptibility (CGEMS) project. rs10993994 remained the most strongly associated marker with prostate cancer risk [
P
= 8.8 × 10
−18
; heterozygous odds ratio (OR) = 1.20, 95% confidence interval (CI): 1.11–1.30; homozygous OR = 1.64, 95% CI: 1.47–1.86 for the adjusted genotype test with 2 df]. In follow-up functional analyses, the T variant of rs10993994 significantly affected expression of in vitro luciferase reporter constructs. In electrophoretic mobility shift assays, the C allele of rs10993994 preferentially binds to the CREB transcription factor. Analysis of tumor cell lines with a CC or CT genotype revealed a high level of
MSMB
gene expression compared with cell lines with a TT genotype. These findings were specific to the alleles of rs10993994 and were not observed for other SNPs determined by sequence analysis of the proximal promoter. Together, our mapping study and functional analyses implicate regulation of expression of
MSMB
as a plausible mechanism accounting for the association identified at this locus. Further investigation is warranted to determine whether rs10993994 alone or in combination with additional variants contributes to prostate cancer susceptibility.
Interleukin-15 combined with an anti-CD40 antibody provides enhanced therapeutic efficacy for murine models of colon cancer
Authors: Zhang Meili , Yao Zhengsheng , Dubois Sigrid , Ju Wei , Müller Jürgen R. , Waldmann Thomas A.
Published: April 2009

IL-15 has potential as an immunotherapeutic agent for cancer treatment because it is a critical factor for the proliferation and activation of natural killer (NK) and CD8
+
T cells. Administration of anti-CD40 antibodies has shown anti-tumor effects in vivo through a variety of mechanisms. Furthermore, activation of CD40 led to increased expression of IL-15 receptor-α by dendritic cells, an action that is critical for trans-presentation of IL-15 to NK and CD8
+
T cells. In this study, we investigated the therapeutic efficacy of the combination regimen of murine IL-15 (mIL-15) with an agonistic anti-CD40 antibody (FGK4.5) in murine lung metastasis models involving CT26 and MC38, which are murine colon cancer cell lines syngeneic to BALB/c and C57BL/6 mice, respectively. Treatment with mIL-15 or the anti-CD40 antibody alone significantly prolonged survival of both CT26 and MC38 tumor-bearing mice compared with the mice in the PBS solution control group (
P
< 0.01). Furthermore, combination therapy with both mIL-15 and the anti-CD40 antibody provided greater therapeutic efficacy as demonstrated by prolonged survival of the mice compared with either mIL-15 or the anti-CD40 antibody-alone groups (
P
< 0.001). We found that NK cells isolated from the mice that received the combination regimen expressed increased levels of intracellular granzyme B and showed stronger cytotoxic activity on the target cells. The findings from this study provide the scientific basis for clinical trials using the combination regimen of IL-15 with an anti-CD40 antibody for the treatment of patients with cancer.
Crystal structure of human aquaporin 4 at 1.8 Å and its mechanism of conductance
Authors: Ho Joseph D. , Yeh Ronald , Sandstrom Andrew , Chorny Ilya , Harries William E. C. , Robbins Rebecca A. , Miercke Larry J. W. , Stroud Robert M.
Published: April 2009

Aquaporin (AQP) 4 is the predominant water channel in the mammalian brain, abundantly expressed in the blood–brain and brain–cerebrospinal fluid interfaces of glial cells. Its function in cerebral water balance has implications in neuropathological disorders, including brain edema, stroke, and head injuries. The 1.8-Å crystal structure reveals the molecular basis for the water selectivity of the channel. Unlike the case in the structures of water-selective AQPs AqpZ and AQP1, the asparagines of the 2 Asn-Pro-Ala motifs do not hydrogen bond to the same water molecule; instead, they bond to 2 different water molecules in the center of the channel. Molecular dynamics simulations were performed to ask how this observation bears on the proposed mechanisms for how AQPs remain totally insulating to any proton conductance while maintaining a single file of hydrogen bonded water molecules throughout the channel.
Nanoparticle-mediated targeting of MAPK signaling predisposes tumor to chemotherapy
Authors: Basu Sudipta , Harfouche Rania , Soni Shivani , Chimote Geetanjali , Mashelkar Raghunath A. , Sengupta Shiladitya
Published: April 2009

The MAPK signal transduction cascade is dysregulated in a majority of human tumors. Here we report that a nanoparticle-mediated targeting of this pathway can optimize cancer chemotherapy. We engineered nanoparticles from a unique hexadentate-polyD,L-lactic acid-co-glycolic acid polymer chemically conjugated to PD98059, a selective MAPK inhibitor. The nanoparticles are taken up by cancer cells through endocytosis and demonstrate sustained release of the active agent, resulting in the inhibition of phosphorylation of downstream extracellular signal regulated kinase. We demonstrate that nanoparticle-mediated targeting of MAPK inhibits the proliferation of melanoma and lung carcinoma cells and induces apoptosis in vitro. Administration of the PD98059-nanoparticles in melanoma-bearing mice inhibits tumor growth and enhances the antitumor efficacy of cisplatin chemotherapy. Our study shows the nanoparticle-mediated delivery of signal transduction inhibitors can emerge as a unique paradigm in cancer chemotherapy.
Ablation of triadin causes loss of cardiac Ca
2+
release units, impaired excitation–contraction coupling, and cardiac arrhythmias
Authors: Chopra Nagesh , Yang Tao , Asghari Parisa , Moore Edwin D. , Huke Sabine , Akin Brandy , Cattolica Robert A. , Perez Claudio F. , Hlaing Thinn , Knollmann-Ritschel Barbara E. C. , Jones Larry R. , Pessah Isaac N. , Allen Paul D. , Franzini-Armstrong Clara , Knollmann Björn C.
Published: April 2009

Heart muscle excitation–contraction (E-C) coupling is governed by Ca
2+
release units (CRUs) whereby Ca
2+
influx via L-type Ca
2+
channels (Cav1.2) triggers Ca
2+
release from juxtaposed Ca
2+
release channels (RyR2) located in junctional sarcoplasmic reticulum (jSR). Although studies suggest that the jSR protein triadin anchors cardiac calsequestrin (Casq2) to RyR2, its contribution to E-C coupling remains unclear. Here, we identify the role of triadin using mice with ablation of the
Trdn
gene (
Trdn
−/−
). The structure and protein composition of the cardiac CRU is significantly altered in
Trdn
−/−
hearts. jSR proteins (RyR2, Casq2, junctin, and junctophilin 1 and 2) are significantly reduced in
Trdn
−/−
hearts, whereas Cav1.2 and SERCA2a remain unchanged. Electron microscopy shows fragmentation and an overall 50% reduction in the contacts between jSR and T-tubules. Immunolabeling experiments show reduced colocalization of Cav1.2 with RyR2 and substantial Casq2 labeling outside of the jSR in
Trdn
−/−
myocytes. CRU function is impaired in
Trdn
−/−
myocytes, with reduced SR Ca
2+
release and impaired negative feedback of SR Ca
2+
release on Cav1.2 Ca
2+
currents (I
Ca
). Uninhibited Ca
2+
influx via I
Ca
likely contributes to Ca
2+
overload and results in spontaneous SR Ca
2+
releases upon β-adrenergic receptor stimulation with isoproterenol in
Trdn
−/−
myocytes, and ventricular arrhythmias in
Trdn
−/−
mice. We conclude that triadin is critically important for maintaining the structural and functional integrity of the cardiac CRU; triadin loss and the resulting alterations in CRU structure and protein composition impairs E-C coupling and renders hearts susceptible to ventricular arrhythmias.
ERα as ligand-independent activator of CDH-1 regulates determination and maintenance of epithelial morphology in breast cancer cells
Authors: Cardamone Maria Dafne , Bardella Chiara , Gutierrez Arantxa , Di Croce Luciano , Rosenfeld Michael G. , Di Renzo Maria Flavia , De Bortoli Michele
Published: April 2009

Estrogen receptor α (ERα) and E-cadherin are primary markers of luminal epithelial breast cancer cells with E-cadherin being a main caretaker of the epithelial phenotype. E-cadherin repression is needed for cancer cells to acquire motile and invasive properties, and it is known that in ER-positive breast cancer cells, estrogen down-regulate E-cadherin gene transcription. We report here that ERα is bound to the E-cadherin promoter in both the presence and the complete absence of estrogen, suggesting an unexpected role for unliganded ERα in E-cadherin transcription. Indeed, our data reveal that activation by unliganded ERα and repression by estrogen-activated ERα require direct binding to a half-estrogen response element within the E-cadherin promoter and exchange from associated coactivators to corepressors. Therefore, these results suggest a pivotal role for unliganded ERα in controlling a fundamental caretaker of the epithelial phenotype in breast cancer cells. Here, we show that ERα-positive breast cancer T47D cells transduced with the sfRON kinase undergo a full epithelial–mesenchymal conversion and lose E-cadherin and ERα expression. Our data show that, although the E-cadherin gene becomes hypermethylated and heterochromatic, kinase inhibitors can restore E-cadherin expression, together with an epithelial morphology in an ERα-dependent fashion. Similarly, transfection of ERα, in the absence of ligands, was sufficient to restore E-cadherin transcription in both sfRON-T47D and other ERα-, E-cadherin-negative cells. Therefore, our results suggest a novel role for the ERα that plays the dual role of ligand-independent activator and ligand-dependent repressor of E-cadherin in breast cancer cells.
An ABC transport system that maintains lipid asymmetry in the Gram-negative outer membrane
Authors: Malinverni Juliana C. , Silhavy Thomas J.
Published: April 2009

The outer membranes (OMs) of Gram-negative bacteria have an asymmetric lipid distribution with lipopolysaccharides at the outer leaflet and phospholipids (PLs) at the inner leaflet. This lipid arrangement is essential for the barrier function of the OM and for the viability of most Gram-negative bacteria. Cells with OM assembly defects or cells exposed to harsh chemical treatments accumulate PLs in the outer leaflet of the OM and this disrupts lipopolysaccharide organization and increases sensitivity to small toxic molecules. We have identified an ABC transport system in
Escherichia coli
with predicted import function that serves to prevent PL accumulation in the outer leaflet of the OM. This highly conserved pathway, which we have termed the Mla pathway for its role in preserving OM lipid asymmetry, is composed of at least 6 proteins and contains at least 1 component in each cellular compartment. We propose that the Mla pathway constitutes a bacterial intermembrane PL trafficking system.
The cost of linguistic loyalty
Authors: Jenkins Devin L.
Published: April 2009

In a census-related study on language maintenance among the Hispanic/Latino population in the southwest United States, Hudson, Hernández-Chávez and Bills (1995) stated that, given negative correlations between language maintenance and years of education and per capita income, “educational and economic success in the Spanish origin population are purchased at the expense of Spanish language maintenance in the home” (1995: 179). While census figures from 1980 make this statement undeniable for the Southwest, the recent growth of the Spanish-language population in the United States, which has grown by a factor of ~2.5 over the last twenty years, begs a reexamination of these correlations. A recent study on the state of Colorado (McCullough & Jenkins 2005) found a correlational weakening, especially with regard to the relationship between language maintenance and median income.  The current study follows the model set forth by Hudson et al. (1995) in examining the interrelationship between the measures of count, density, language loyalty and retention based on 2000 census data, as well as the relationship between these metrics and socioeconomic and demographic variables, including income and education. While some relationships existed in 2000 much in the same way that they did in the 1980 data, especially with regard to count and density, the measures of loyalty and retention saw marked reductions in their correlations with social variables.
The dynamics of Spanish maintenance and shift in Arizona
Authors: Cashman Holly R.
Published: April 2009

Within the discussion of the dynamics of Spanish language maintenance and shift to English in the southwestern U.S., this article takes a magnifying glass to one Southwest state in particular, Arizona, and the societal pressures that impact language maintenance and shift. Rather than focus on speakers’ language use across domains or attitudes about Spanish and English, this article examines the wider sociopolitical context of language use through the lens of ethnolinguistic vitality and subjective ethnolinguistic vitality, and from the perspective of the competing forces of language panic and language pride.
Spanish receptive bilinguals
Authors: Beaudrie Sara
Published: April 2009

The growing amount of research in heritage languages (HL) consistently suggests that HL learners are a diverse population with language abilities that span across the whole spectrum of the bilingual range (Valdés 2001). Receptive bilinguals, sometimes called passive bilinguals, are at one end of this bilingual range, almost at the verge of culminating the language shift towards English monolingualism. This population of HL students has received scant attention from HL programs and researchers alike. The present study fills this gap in the literature by focusing specifically on receptive bilinguals of different generations enrolled in Spanish classes at a large university in the southwestern United States. It seeks to provide insights into their cultural and linguistic profile so as to begin to understand the factors that have influenced their current Spanish use and linguistic abilities in the language.
Spanish heritage speakers in the Southwest
Authors: Martínez-Mira María-Isabel
Published: April 2009

Several studies have looked into the different uses of indicative and subjunctive in the Spanish of heritage speakers. Generally speaking, research seems to show that mood simplification is taking place in heritage speakers’ Spanish. Mood and modal alternation is of particular interest to research on language change and contact due to the wide variation in the ability of heritage speakers to produce and apply it. (This is, in part, no doubt, due to their embodiment of a complex relationship between syntactic form, semantics and pragmatic meaning.) The present study examines the use of the indicative/subjunctive in the written and oral Spanish production of one group of heritage language speakers to find out which similarities/differences can be found when compared to monolingual speakers and what this says about how their linguistic systems are configurated.
“A pattern, precedent, and lively warrant”: Emulation, Rhetoric, and Cruel Propriety inTitus Andronicus
Authors: Dickson Vernon Guy
Published: April 2009

Shakespeare'sTitus Andronicuscritically engages and enacts teachings and patterns of emulation, including those of Quintilian, Roger Ascham, and other contemporary humanists and playwrights, pressing emulation's uses to extremes that suggest that imitative self-fashioning potentially results in monstrous or fragmented characters, decisions, and texts. The professed aim of the grammar-school education, the ability to judge well, is conflicted byTitus's exposure of judgment as itself a contested concept, locked within a circularity of intertextual precedents. Titus's excessive, even parodic, repetition of emulative strategies acts as a rebuttal of seemingly straightforward humanist models of character, judgment, self, and decorum.
“Perplex't Paths”: Youth and Authority in Milton'sMask*
Authors: Greteman Blaine
Published: April 2009

This essay argues that John Milton'sA Mask Presented at Ludlow Castle(1634) is influenced by early modern concepts of childhood in a way that critics have not recognized. Childhood was a problematic concept in contemporary religious, pedagogical, and legal discourses. Children were depicted as models of submission, but prone to impetuous indiscretion, and their path to adult agency was strewn with pitfalls, especially in the liminal period of youth.A Maskengages with and transforms these discourses. It rejects the political quietism routinely associated with childhood and shows that the child's unique sensitivity may offer a route to a particularly powerful kind of voice.
Compact non-orientable surfaces of genus 4 with extremal metric discs
Authors: Nakamura Gou
Published: April 2009

A compact hyperbolic surface of genus

g
g

is said to be extremal if it admits an extremal disc, a disc of the largest radius determined by

g
g

. We know how many extremal discs are embedded in a non-orientable extremal surface of genus

g
=
3

g=3

or

g
>
6

g>6

. We show in the present paper that there exist

144
144

non-orientable extremal surfaces of genus

4
4

, and find the locations of all extremal discs in those surfaces. As a result, each surface contains at most two extremal discs. Our methods used here are similar to those in the case of

g
=
3

g=3

.
Aqueous Extract of Shi‐Liu‐Wei‐Liu‐Qi‐Yin Induces G2/M Phase Arrest and Apoptosis in Human Bladder Carcinoma Cells via Fas and Mitochondrial Pathway
Authors: Ou Ting-Tsz , Wang Chau-Jong , Hung Guang-Uei , Wu Cheng-Hsun , Lee Huei-Jane
Published: April 2009

Shi‐Liu‐Wei‐Liu‐Qi‐Yin (SLWLQY) was traditionally used to treat cancers. However, scientific evidence of the anticancer effects still remains undefined. In this study, we aimed to clarify the possible mechanisms of SLWLQY in treating cancer. We evaluated the effects of SLWLQY on apoptosis‐related experiments inducing in TSGH‐8301 cells by (i) 3‐(4,5‐dimethylthiazol‐zyl)‐2,5‐diphenylterazolium bromide (MTT) for cytotoxicity; (ii) cell‐cycle analysis and (iii) western blot analysis of the G2/M‐phase and apoptosis regulatory proteins. Human bladder carcinoma TSGH‐8301 cells were transplanted into BALB/c nude mice as a tumor model for evaluating the antitumor effect of SLWLQY. Treatment of SLWLQY resulted in the G2/M phase arrest and apoptotic death in a dose‐dependent manner, accompanied by a decrease in cyclin‐dependent kinases (cdc2) and cyclins (cyclin B1). SLWLQY stimulated increases in the protein expression of Fas and FasL, and induced the cleavage of caspase‐3, caspase‐9 and caspase‐8. The ratio of Bax/Bcl2 was increased by SLWLQY treatment. SLWLQY markedly reduced tumor size in TSGH‐8301 cells‐xenografted tumor tissues. In the tissue specimen, SLWLQY up‐regulated the expression of Fas, FasL and Bax proteins, and down‐regulated Bcl2 as well as in in vitro assay. Our results showed that SLWLQY reduced tumor growth, caused cell‐cycle arrest and apoptosis in TSGH‐8301 cells via the Fas and mitochondrial pathway.
Lyprinol—Is It a Useful Anti‐Inflammatory Agent?
Authors: Doggrell Sheila A.
Published: April 2009

The New Zealand green lipped mussel preparation Lyprinol is available without a prescription from a supermarket, pharmacy or Web. The Food and Drug Administration have recently warned Lyprinol USA about their extravagant anti‐inflammatory claims for Lyprinol appearing on the web. These claims are put to thorough review. Lyprinol does have anti‐inflammatory mechanisms, and has anti‐inflammatory effects in some animal models of inflammation. Lyprinol may have benefits in dogs with arthritis. There are design problems with the clinical trials of Lyprinol in humans as an anti‐inflammatory agent in osteoarthritis and rheumatoid arthritis, making it difficult to give a definite answer to how effective Lyprinol is in these conditions, but any benefit is small. Lyprinol also has a small benefit in atopic allergy. As anti‐inflammatory agents, there is little to choose between Lyprinol and fish oil. No adverse effects have been reported with Lyprinol. Thus, although it is difficult to conclude whether Lyprinol does much good, it can be concluded that Lyprinol probably does no major harm.
Remote ischaemic pre‐conditioning does not attenuate ischaemic left ventricular dysfunction in humans
Authors: Hoole Stephen P. , Khan Sadia N. , White Paul A. , Heck Patrick M. , Kharbanda Rajesh K. , Densem Cameron G. , Clarke Sarah C. , Shapiro Leonard M. , Schofield Peter M. , O'Sullivan Michael , Dutka David P.
Published: April 2009

Aims

Remote ischaemic pre‐conditioning (RIPC) reduces distant tissue ischaemia reperfusion injury. We tested the hypothesis that RIPC would protect the left ventricle (LV) from ischaemic dysfunction and stunning.

Methods and results

Forty‐two patients with single vessel coronary disease and normal LV function were prospectively recruited. Twenty patients had repeated conductance catheter assessment of LV function during serial coronary occlusions with/without RIPC and a further 22 patients underwent serial dobutamine stress echocardiography and tissue Doppler analysis with/without RIPC. Remote ischaemic pre‐conditioning was induced by three 5 min inflations of a blood pressure cuff around the upper arm. RIPC did not diminish the degree of ischaemic LV dysfunction during coronary balloon occlusion (Tau, ms: 59.2 (2.8) vs. 62.8 (2.8), P = 0.15) and there was evidence of cumulative LV dysfunction despite RIPC [ejection fraction (EF), %: 54.3 (5.8) vs. 44.9 (3.7), P = 0.03]. Remote ischaemic pre‐conditioning did not improve contractile recovery during reperfusion (EF, %: 51.7 (3.6) vs. 51.5 (5.7), P = 0.88 and Tau, ms: 55.6 (2.8) vs. 56.0 (2.0), P = 0.85). A neutral effect of RIPC on LV function was confirmed by tissue Doppler analysis of ischaemic segments at peak dobutamine (Vs, cm s−1 control: 8.2 (0.4) vs. RIPC 8.1 (0.4), P = 0.43) and in recovery.

Conclusion

RIPC does not attenuate ischaemic LV dysfunction in humans.
Palliative care in heart failure: a position statement from the palliative care workshop of the Heart Failure Association of the European Society of Cardiology
Authors: Jaarsma Tiny , Beattie James M. , Ryder Mary , Rutten Frans H. , McDonagh Theresa , Mohacsi Paul , Murray Scott A. , Grodzicki Thomas , Bergh Ingrid , Metra Marco , Ekman Inger , Angermann Christiane , Leventhal Marcia , Pitsis Antonis , Anker Stefan D. , Gavazzi Antonello , Ponikowski Piotr , Dickstein Kenneth , Delacretaz Etienne , Blue Lynda , Strasser Florian , McMurray John ,   on behalf of the Advanced Heart Failure Study Group of the HFA of the ESC
Published: April 2009

Heart failure is a serious condition and equivalent to malignant disease in terms of symptom burden and mortality. At this moment only a comparatively small number of heart failure patients receive specialist palliative care. Heart failure patients may have generic palliative care needs, such as refractory multifaceted symptoms, communication and decision making issues and the requirement for family support. The Advanced Heart Failure Study Group of the Heart Failure Association of the European Society of Cardiology organized a workshop to address the issue of palliative care in heart failure to increase awareness of the need for palliative care. Additional objectives included improving the accessibility and quality of palliative care for heart failure patients and promoting the development of heart failure‐orientated palliative care services across Europe. This document represents a synthesis of the presentations and discussion during the workshop and describes recommendations in the area of delivery of quality care to patients and families, education, treatment coordination, research and policy.
Microbial community profiling for human microbiome projects: Tools, techniques, and challenges
Authors: Hamady Micah , Knight Rob
Published: April 2009

High-throughput sequencing studies and new software tools are revolutionizing microbial community analyses, yet the variety of experimental and computational methods can be daunting. In this review, we discuss some of the different approaches to community profiling, highlighting strengths and weaknesses of various experimental approaches, sequencing methodologies, and analytical methods. We also address one key question emerging from various Human Microbiome Projects: Is there a substantial core of abundant organisms or lineages that we all share? It appears that in some human body habitats, such as the hand and the gut, the diversity among individuals is so great that we can rule out the possibility that any species is at high abundance in all individuals: It is possible that the focus should instead be on higher-level taxa or on functional genes instead.
Pathogenesis of chronic urticaria
Authors: Kaplan A. P. , Greaves M.
Published: April 2009

Chronic urticaria is defined as the presence of urticaria (hives) for at least 6 weeks with the assumption that it occurs daily or close to it. If we eliminate physical urticarias and urticarial vasculitis from consideration, the remainder can be divided into autoimmune chronic urticaria (45%) and idiopathic chronic urticaria (55%). The autoimmune subgroup is associated with the IgG anti‐IgE receptor α subunit in 35–40% of patients and IgG anti‐IgE in an additional 5–10%. These autoantibodies have been shown to activate blood basophils and cutaneous mast cellsin vitrowith augmentation of basophil activation by complement and release of C5a, in particular. Binding methods (immunoblot and ELISA) yield positives in many autoimmune diseases as well as occasional normal subjects or patients with other forms of urticaria but most such sera are non‐functional. Activation of basophils or mast cells causing histamine release is quite specific for chronic urticaria and defines the autoimmune subgroup. Although pathogenicity is not formally proven, the antibodies cause wealing upon intradermal injection, and removal of the autoantibody leads to remission. A cellular infiltrate is seen to be characterized by mast cell degranulation and infiltration of CD4+T lymphocytes, monocytes, neutrophils, eosinophils, and basophils. The intensity of the infiltrate and clinical severity of the disease (including accompanying angio‐oedema) is more severe in the autoimmune subpopulation. This latter group also has a higher evidence of human leucocyte antigen DR alleles associated with autoimmunity and a 25% incidence of antithyroid antibodies with diagnosed hypothyroidism in some. Hypo‐responsiveness of patients' basophils to anti‐IgE and hyperresponsiveness to serum defines another subpopulation (at least 50%) that overlaps the idiopathic and autoimmune subgroups. Hypo‐responsiveness to anti‐IgE has been shown to be associated with elevated levels of cytoplasmic phosphatases that inhibit degranulation. Reversal of the abnormality is seen with disease remission. Further work will be needed to distinguish whether this is a cause or a consequence of persistent urticaria and to further assess the relationship (or lack thereof) of altered responsiveness (decreased or increased) with the presence or absence of activating autoantibodies.
Programmed death (PD)-1 molecule and its ligand PD-L1 distribution among memory CD4 and CD8 T cell subsets in human immunodeficiency virus-1-infected individuals
Authors: Rosignoli G , Lim C H , Bower M , Gotch F , Imami N
Published: April 2009

Human immunodeficiency virus (HIV)-1 causes T cell anergy and affects T cell maturation. Various mechanisms are responsible for impaired anti-HIV-1-specific responses: programmed death (PD)-1 molecule and its ligand PD-L1 are negative regulators of T cell activity and their expression is increased during HIV-1 infection. This study examines correlations between T cell maturation, expression of PD-1 and PD-L1, and the effects of their blockade. Peripheral blood mononuclear cells (PBMC) from 24 HIV-1+ and 17 uninfected individuals were phenotyped for PD-1 and PD-L1 expression on CD4+ and CD8+ T cell subsets. The effect of PD-1 and PD-L1 blockade on proliferation and interferon (IFN)-γ production was tested on eight HIV-1+ patients. Naive (CCR7+CD45RA+) CD8+ T cells were reduced in HIV-1 aviraemic (P = 0·0065) and viraemic patients (P = 0·0130); CD8 T effector memory subsets [CCR7-CD45RA–(TEM)] were increased in HIV-1+ aviraemic (P = 0·0122) and viraemic (P = 0·0023) individuals versus controls. PD-1 expression was increased in CD4 naive (P = 0·0496), central memory [CCR7+CD45RA– (TCM); P = 0·0116], TEM (P = 0·0037) and CD8 naive T cells (P = 0·0133) of aviraemic HIV-1+versus controls. PD-L1 was increased in CD4 TEMRA (CCR7-CD45RA+, P = 0·0119), CD8 TEM (P = 0·0494) and CD8 TEMRA (P = 0·0282) of aviraemic HIV-1+versus controls. PD-1 blockade increased HIV-1-specific proliferative responses in one of eight patients, whereas PD-L1 blockade restored responses in four of eight patients, but did not increase IFN-γ-production. Alteration of T cell subsets, accompanied by increased PD-1 and PD-L1 expression in HIV-1 infection contributes to anergy and impaired anti-HIV-1-specific responses which are not rescued when PD-1 is blocked, in contrast to when PD-L1 is blocked, due possibly to an ability to bind to receptors other than PD-1.
Attenuation of massive cytokine response to the staphylococcal enterotoxin B superantigen by the innate immunomodulatory protein lactoferrin
Authors: Hayworth J L , Kasper K J , Leon-Ponte M , Herfst C A , Yue D , Brintnell W C , Mazzuca D M , Heinrichs D E , Cairns E , Madrenas J , Hoskin D W , McCormick J K , Haeryfar S M M
Published: April 2009

Staphylococcal enterotoxin B (SEB) is a pyrogenic exotoxin and a potent superantigen which causes massive T cell activation and cytokine secretion, leading to profound immunosuppression and morbidity. The inhibition of SEB-induced responses is thus considered a goal in the management of certain types of staphylococcal infections. Lactoferrin (LF) is a multi-functional glycoprotein with both bacteriostatic and bactericidal activities. In addition, LF is known to have potent immunomodulatory properties. Given the anti-microbial and anti-inflammatory properties of this protein, we hypothesized that LF can modulate T cell responses to SEB. Here, we report that bovine LF (bLF) was indeed able to attenuate SEB-induced proliferation, interleukin-2 production and CD25 expression by human leucocyte antigen (HLA)-DR4 transgenic mouse T cells. This inhibition was not due to bLF’s iron-binding capacity, and could be mimicked by the bLF-derived peptide lactoferricin. Cytokine secretion by an engineered SEB-responsive human Jurkat T cell line and by peripheral blood mononuclear cells from healthy donors was also inhibited by bLF. These findings reveal a previously unrecognized property of LF in modulation of SEB-triggered immune activation and suggest a therapeutic potential for this naturally occurring protein during toxic shock syndrome.
Modeling larval Calanus finmarchicus on Georges Bank: time‐varying mortality rates and a cannibalism hypothesis
Authors: NEUHEIMER A. B. , GENTLEMAN W. C. , GALLOWAY C. L. , JOHNSON C. L.
Published: April 2009

Throughout the North Atlantic, the copepod Calanus finmarchicus dominates the zooplankton biomass, linking primary production and higher trophic levels. On Georges Bank, the peak abundance of larval (naupliar) stages occurs in March–April and represents a potential source of prey for cod and haddock larvae. Following this maximum, naupliar abundance declines dramatically, reaching a minimum in May and increasing again in June. Explaining the naupliar seasonal cycle is critical for predicting climate effects on C. finmarchicus dynamics, including whether environmental variability may lead to a mismatch with larval fish. Here, an age‐within‐stage population dynamics model is used to investigate the factors controlling the temporal variation of C. finmarchicus nauplii in three Georges Bank sub‐regions. The model incorporates temperature‐ and food‐dependent development and egg production, as well as female abundance derived from the US Global Ocean Ecosystem Dynamics (GLOBEC) program. Use of field‐estimated constant mortality rates overestimates May abundances by as much as an order of magnitude. These data/model discrepancies can not be explained by temperature or food‐limitation effects on physiological rates. Instead, accurate simulation requires use of time‐varying early stage mortalities, which differ from published estimates in both magnitude and trend. These mortality rates are correlated with C. finmarchicus female abundance, implying cannibalism as a possible regulatory factor. Thus, the biological control of predation (including cannibalism) must be considered to predict the effects of climate on C. finmarchicus and associated larval fish populations.
Nurse and parent partnership during children’s vaccinations: a conversation analysis
Authors: Plumridge Elizabeth , Goodyear‐Smith Felicity , Ross Jim
Published: April 2009

Title.  Nurse and parent partnership during children’s vaccinations: a conversation analysis.

Aim.  This paper is a report of a study conducted to examine the elements of partnership and communication between nurses and parents during actual events of immunization.

Background.  Childhood immunizations require collaboration with parents, who may be anxious about immunization safety or subjecting their children to painful procedures.

Methods.  Ten interactions during immunization events from six purposively selected general practices were videoed in 2005, giving 168 minutes of talk. Conversation analysis was conducted on talk during the short phase of injection administration.

Findings.  During the immunization event nurse and mother talked to the baby/toddler rather than each other. Concurrent talk acted as a chorus, marked by sing‐sing prosody, shared laughter and talk or reassuring noises. In coordinated talk nurse and parent took turns. Although overlap might occur, the actions accomplished by each speaker were different. Nurses most commonly cued bravery or stoicism to the child and stressed the progress made in administering the injections. In the less common pattern when pain was recognized as inevitable and there was no stress on stoicism and progress towards completion, the child displayed more distress and began crying before the injection.

Conclusion.  Communication skills and rapport are core to nursing work. What happens at the micro‐level of turn‐taking, where prosody and the actions achieved in talk, is of key importance. Our study suggests ‘small talk’ is of major importance – a practical professional skill in which nurses not only align with parents but simultaneously cue both mother and child about how the immunization should be conducted.
Extending immunofluorescence detection limits in whole paraffin‐embedded formalin fixed tissues using hyperspectral confocal fluorescence imaging
Authors: CONSTANTINOU P. , DACOSTA R.S. , WILSON B.C.
Published: April 2009

A major problem in microscopic imaging of ex vivo tissue sections stained with fluorescent agents (e.g. antibodies, peptides) is the confounding presence of background tissue autofluorescence. Autofluorescence limits (1) the accuracy of differentiating background signals from single and multiple fluorescence labels and (2) reliable quantification of fluorescent signals. Advanced techniques such as hyperspectral imaging and spectral unmixing can be applied to essentially remove this autofluorescent signal contribution, and this work attempts to quantify the effectiveness of autofluorescence spectral unmixing in a tumour xenograft model. Whole‐specimen single‐channel fluorescence images were acquired using excitation wavelengths of 488 nm (producing high autofluorescence) and 568 nm (producing negligible autofluorescence). These single‐channel data sets are quantified against hyperspectral images acquired at 488 nm using a prototype whole‐slide hyperspectral fluorescence scanner developed in our facility. The development and further refinement of this instrument will improve the quantification of weak fluorescent signals in fluorescence microscopy studies of ex vivo tissues in both preclinical and clinical applications.
An improved dynamic model of tuning fork probe for scanning probe microscopy
Authors: NG B.P. , ZHANG Y. , KOK S.W. , SOH Y.C.
Published: April 2009

This paper presents a two coupled oscillators model to describe the dynamics of a tuning fork with a probe attached. The two coupled oscillators are unbalanced only in their effective masses and the damping ratios. By applying a frequency domain system identification approach in experimental investigation of various probe attachment cases, a good accuracy of the model is demonstrated. The effectiveness of the model is further demonstrated in quantitative analysis of the noise performance and the sensitivity of force sensing with a tuning fork probe. Compared with existing models, the proposed model can more accurately characterize the dynamics of a tuning fork probe.
Preparation of wholemount mouse intestine for high‐resolution three‐dimensional imaging using two‐photon microscopy
Authors: APPLETON P.L. , QUYN A.J. , SWIFT S. , NÄTHKE I.
Published: April 2009

Visualizing overall tissue architecture in three dimensions is fundamental for validating and integrating biochemical, cell biological and visual data from less complex systems such as cultured cells. Here, we describe a method to generate high‐resolution three‐dimensional image data of intact mouse gut tissue. Regions of highest interest lie between 50 and 200 μm within this tissue. The quality and usefulness of three‐dimensional image data of tissue with such depth is limited owing to problems associated with scattered light, photobleaching and spherical aberration. Furthermore, the highest‐quality oil‐immersion lenses are designed to work at a maximum distance of ≤10–15 μm into the sample, further compounding the ability to image at high‐resolution deep within tissue. We show that manipulating the refractive index of the mounting media and decreasing sample opacity greatly improves image quality such that the limiting factor for a standard, inverted multi‐photon microscope is determined by the working distance of the objective as opposed to detectable fluorescence. This method negates the need for mechanical sectioning of tissue and enables the routine generation of high‐quality, quantitative image data that can significantly advance our understanding of tissue architecture and physiology.
Low viraemia at enrollment in children with chronic hepatitis C favours spontaneous viral clearance
Authors: Chen S.‐T. , Ni Y.‐H. , Chen P.‐J. , Chen H.‐L. , Jeng Y.‐M. , Lu M.‐Y. , Wu J.‐F. , Hsu H.‐Y. , Chang M.‐H.
Published: April 2009

Summary. The significance of hepatitis C viral (HCV)‐RNA levels in long‐term clinical outcomes of children with chronic HCV infection is not well understood. We conducted a long‐term follow‐up study of 42 children with chronic HCV infection that included clinical evaluation, biochemical tests, HCV genotyping and repeated quantitative HCV‐RNA detection. Patients were divided into low and high viraemia groups according to RNA levels at enrollment (below/above 4.5 × 104 IU/mL), and clinical, biochemical and virological factors were evaluated. Overall, 14.3% (6/42) of patients developed spontaneous viral clearance during a median 10.1 years of follow‐up. HCV‐RNA levels at enrollment and mean RNA levels during follow‐up for each patient were significantly correlated (R = 0.9018, 95% CI: 0.6637–0.9038,P ≤ 0.001). HCV‐RNA level fluctuation was within two log units in 76% of patients. Cumulative viraemia probability during follow‐up could be predicted by viraemia levels at enrollment (P = 0.0092). Chronic HCV‐infected children, with an RNA level below 4.5 × 104 IU/mL at enrollment, have a higher spontaneous viral clearance rate.
The relation between stomatal aperture and gas exchange under consideration of pore geometry and diffusional resistance in the mesophyll
Authors: KAISER HARTMUT
Published: April 2009

The quantitative relation between stomatal aperture and gas exchange through the stomatal pore can be described by physical models derived from Fick's first law of diffusion. Such models, usually based on a simplified pore geometry, are used to calculate leaf conductance from stomatal pore dimensions or vice versa. In this study a combination of gas‐exchange measurements and simultaneous microscopical observations of stomatal apertures was used to empirically determine this relationship. The results show a substantial deviation between measured stomatal conductance and that calculated from the simplified models. The main difference is a much steeper increase of conductance with aperture at small apertures. When the calculation was based on a realistic pore geometry derived from confocal laser scanning microscopy, a good fit to the experimentally found relationship could be obtained if additionally a significant contribution of a mesophyll diffusional resistance was taken into account.
Frost tolerance in excised leaves of the common bugle (Ajuga reptans L.) correlates positively with the concentrations of raffinose family oligosaccharides (RFOs)
Authors: PETERS SHAUN , KELLER FELIX
Published: April 2009

Mass increases in raffinose family oligosaccharides (RFOs, α1,6‐galactosyl extensions of sucrose) are well documented in the generative tissues of many plants upon cold acclimation, and they (i.e. mainly the two shortest RFO members, raffinose and stachyose) have been suggested as frost stress protectants. Our focus here was on the longer RFO members as they commonly occur in the frost‐hardy evergreen labiate Ajuga reptans in its natural habitat, and accumulate to their highest concentrations in winter when the plant is faced with sub‐zero temperatures. We examined the effects of RFO concentration and chain length on frost tolerance using excised leaves which accumulate long‐chain RFOs under both cold and warm conditions, thereby uncoupling the acclimation temperature from RFO production. We demonstrated that frost tolerance in excised A. reptans leaves correlates positively with long‐chain RFO accumulation under both acclimation temperatures. After 24 d post‐excision in the warm, the leaves had increased their RFO concentrations (mainly long‐chain RFOs) 22‐fold to 78 mg g−1 fresh weight, and decreased their EL50 values (temperature at which 50% leakage occurred) from −10.5 to −24.5 °C, suggesting a protective role for these oligosaccharides in the natural frost tolerance of A. reptans.