bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vivo Wall Shear Stress Distribution in the Carotid Artery
Authors: Markl Michael , Wegent Felix , Zech Timo , Bauer Simon , Strecker Christoph , Schumacher Martin , Weiller Cornelius , Hennig Jürgen , Harloff Andreas
Published: September 2010

Background—

The purpose of this study was to analyze the in vivo distribution of absolute wall shear stress (WSS
abs
) and oscillatory shear index (OSI) in the carotid bifurcation and to evaluate its dependence on bifurcation geometry, the presence of internal carotid artery (ICA) stenosis, and recanalization therapy.

Methods and Results—

Time-resolved 3D blood flow was acquired with flow-sensitive 4D MRI in 64 normal carotid bifurcations and 17 carotid arteries with moderate ICA stenosis (48±6%) or after surgical recanalization. Among 64 normal arteries, atherogenic wall parameters were consistently concentrated in proximal bulb regions of the common (CCA) and internal (ICA) carotid arteries. The fraction of the carotid bulb exposed to atherosclerosis-prone wall parameters (low WSS
abs
below and high OSI above group-defined 20% and 10% thresholds) was correlated with the individual bifurcation geometry. Multiple regressions revealed significant (
P
<0.01) relationships (β, 0.44 to 0.48) between the areas with atherosclerosis-prone wall parameters and the d
ICA
/d
CCA
diameter ratio. The size of regions exposed to high OSI demonstrated highly significant (
P
≤0.01) relationships with all analyzed geometry parameters (d
ICA
/d
CCA
β, 0.48; tortuosity β, ≤−0.56; bifurcation angle β, ≥0.47). Moderate ICA stenosis altered the distribution of wall parameters (45%/61% reduction of individually low WSS
abs
/high OSI in the proximal ICA), which were relocated to segments distal to the arterial stenosis. WSS
abs
/OSI topology after recanalization was similar compared with the normal wall parameter distribution.

Conclusions—

Flow-sensitive 4D MRI identified alterations in the segmental in vivo WSS distribution associated with atherosclerotic disease, surgical therapy, and individual bifurcation geometry and could be a valuable technique to assess the individual risk of flow-mediated atherosclerosis and carotid plaque progression.
Collagen XV Is Necessary for Modeling of the Extracellular Matrix and Its Deficiency Predisposes to Cardiomyopathy
Authors: Rasi Karolina , Piuhola Jarkko , Czabanka Marcus , Sormunen Raija , Ilves Mika , Leskinen Hanna , Rysä Jaana , Kerkelä Risto , Janmey Paul , Heljasvaara Ritva , Peuhkurinen Keijo , Vuolteenaho Olli , Ruskoaho Heikki , Vajkoczy Peter , Pihlajaniemi Taina , Eklund Lauri
Published: September 2010

Rationale:

The extracellular matrix (ECM) is a major determinant of the structural integrity and functional properties of the myocardium in common pathological conditions, and changes in vasculature contribute to cardiac dysfunction. Collagen (Col) XV is preferentially expressed in the ECM of cardiac muscle and microvessels.

Objective:

We aimed to characterize the ECM, cardiovascular function and responses to elevated cardiovascular load in mice lacking Col XV (
Col15a1
−/−
) to define its functional role in the vasculature and in age- and hypertension-associated myocardial remodeling.

Methods and Results:

Cardiac structure and vasculature were analyzed by light and electron microscopy. Cardiac function, intraarterial blood pressure, microhemodynamics, and gene expression profiles were studied using echocardiography, telemetry, intravital microscopy, and PCR, respectively. Experimental hypertension was induced with angiotensin II or with a nitric oxide synthesis inhibitor. Under basal conditions, lack of Col XV resulted in increased permeability and impaired microvascular hemodynamics, distinct early-onset and age-dependent defects in heart structure and function, a poorly organized fibrillar collagen matrix with marked interstitial deposition of nonfibrillar protein aggregates, increased tissue stiffness, and irregularly organized cardiomyocytes. In response to experimental hypertension,
Col15a1
gene expression was increased in the left ventricle of wild-type mice, and mRNA expression of natriuretic peptides (ANP and BNP) and ECM modeling were abnormal in
Col15a1
−/−
mice.

Conclusions:

Col XV is necessary for ECM organization in the heart, and for the structure and functions of microvessels. Col XV deficiency leads to a complex cardiac phenotype and predisposes the subject to pathological responses under cardiac stress.
The Cardiac Desmosome and Arrhythmogenic Cardiomyopathies
Authors: Delmar Mario , McKenna William J.
Published: September 2010

Intercellular communication is essential for proper cardiac function. Mechanical and electrical activity need to be synchronized so that the work of individual myocytes transforms into the pumping function of the organ. Mechanical continuity is provided by desmosomes and adherens junctions, while gap junctions provide a pathway for passage of ions and small molecules between cells. These complexes preferentially reside at the site of end-end contact between myocytes, within the intercalated disc. Recognition that some forms of arrhythmogenic cardiomyopathy are caused by mutations in desmosomal protein genes has galvanized interest in the biology of the desmosome and its interactions with other junctional molecules. This review presents the cellular and molecular biology of the desmosome, current knowledge on the relation of desmosomal mutations and disease phenotypes, and an overview of the molecular pathophysiology of arrhythmogenic right ventricular cardiomyopathy. Clinical experience and results from cellular and animal models provide insights into the intercalated disc as a functional unit and into the basic substrates that underlie pathogenesis and arrhythmogenesis of arrhythmogenic right ventricular cardiomyopathy.
Loss of PI3Kγ Enhances cAMP-Dependent MMP Remodeling of the Myocardial N-Cadherin Adhesion Complexes and Extracellular Matrix in Response to Early Biomechanical Stress
Authors: Guo Danny , Kassiri Zamaneh , Basu Ratnadeep , Chow Fung L. , Kandalam Vijay , Damilano Federico , Liang Wenbin , Izumo Seigo , Hirsch Emilio , Penninger Josef M. , Backx Peter H. , Oudit Gavin Y.
Published: September 2010

Rationale:

Mechanotransduction and the response to biomechanical stress is a fundamental response in heart disease. Loss of phosphoinositide 3-kinase (PI3K)γ, the isoform linked to G protein–coupled receptor signaling, results in increased myocardial contractility, but the response to pressure overload is controversial.

Objective:

To characterize molecular and cellular responses of the PI3Kγ knockout (KO) mice to biomechanical stress.

Methods and Results:

In response to pressure overload, PI3KγKO mice deteriorated at an accelerated rate compared with wild-type mice despite increased basal myocardial contractility. These functional responses were associated with compromised phosphorylation of Akt and GSK-3α. In contrast, isolated single cardiomyocytes from banded PI3KγKO mice maintained their hypercontractility, suggesting compromised interaction with the extracellular matrix as the primary defect in the banded PI3KγKO mice. β-Adrenergic stimulation increased cAMP levels with increased phosphorylation of CREB, leading to increased expression of cAMP-responsive matrix metalloproteinases (MMPs), MMP2, MT1-MMP, and MMP13 in cardiomyocytes and cardiofibroblasts. Loss of PI3Kγ resulted in increased cAMP levels with increased expression of MMP2, MT1-MMP, and MMP13 and increased MMP2 activation and collagenase activity in response to biomechanical stress. Selective loss of N-cadherin from the adhesion complexes in the PI3KγKO mice resulted in reduced cell adhesion. The β-blocker propranolol prevented the upregulation of MMPs, whereas MMP inhibition prevented the adverse remodeling with both therapies, preventing the functional deterioration in banded PI3KγKO mice. In banded wild-type mice, long-term propranolol prevented the adverse remodeling and systolic dysfunction with preservation of the N-cadherin levels.

Conclusions:

The enhanced propensity to develop heart failure in the PI3KγKO mice is attributable to a cAMP-dependent upregulation of MMP expression and activity and disorganization of the N-cadherin/β-catenin cell adhesion complex. β-Blocker therapy prevents these changes thereby providing a novel mechanism of action for these drugs.
No First Use: The Next Step for U.S. Nuclear Policy
Authors: Gerson Michael S.
Published: September 2010

The release of the Barack Obama administration's much-anticipated Nuclear Posture Review (NPR) concluded an intense, yearlong effort to revamp U.S. nuclear weapons policy to better address modern threats. Despite general agreement that the United States' nuclear policy and posture was in need of overhaul, there were strong disagreements over what kinds of changes should be made. At the core of these debates was the issue of U.S. declaratory policy—the stated role and purpose of U.S. nuclear weapons. Whereas some members of the administration advocated that the United States retain all of the flexibility and options afforded by the policy of calculated ambiguity, others contended that to fulfill President Obama's commitment to “put an end to Cold War thinking” and “reduce the role of nuclear weapons in U.S. national security strategy,” the United States should adopt a more restrictive nuclear policy such as no first use (NFU), perhaps in the form of a declaration that the “sole purpose” of U.S. nuclear weapons is to deter a nuclear attack. By not adopting NFU, the NPR missed an important opportunity to reduce the role of nuclear weapons in U.S. strategy. The traditional case for NFU hinges on the argument that the threat of nuclear first use is unnecessary for deterrence. Yet the continued U.S. option to use nuclear weapons first is not only unnecessary but dangerous. Given the size and accuracy of the current U.S. nuclear arsenal, and given the variation in the nuclear capabilities of current and potential adversaries, the first-use option risks creating instabilities in a severe crisis that increase the chances of accidental, unauthorized, or deliberate nuclear use. In a future crisis with a nuclear-armed state, the fear—whether real or imagined—that the United States might attempt a disarming nuclear first-strike increases the possibility of nuclear escalation.
When a place is not a place: encoding of spatial information is dependent on reward type
Authors: Sulikowski Danielle , Burke Darren
Published: September 2010

The adaptationist perspective investigates how an animal's cognition has been shaped by the informational properties of the environment. The information that is useful may vary from one context to another. In the current study we examine how manipulating the foraging context (the type of resource being foraged) could affect the way spatial information is used by the forager. Noisy miner birds (omnivorous honeyeaters) were given spatial working memory tasks in which they searched baited and unbaited feeders for either nectar or invertebrates. We hypothesised that noisy miners would encode the locations of baited and unbaited feeders equally well when foraging for nectar (all flowers, whether containing nectar or not are places to remember and avoid while foraging on a plant). When foraging for invertebrates, however, we predicted that noisy miner birds would not encode the locations of unbaited feeders as effectively as baited feeders (in a natural patch of invertebrates there is no cue to differentiate a point location where a prey item has not been found from the rest of the potentially homogenous patch). As predicted, birds foraging for invertebrates made more revisits to unbaited than baited feeders, with no such difference evident when birds were foraging for nectar.
Close social associations in animals and humans: functions and mechanisms of friendship
Authors: Massen Jorg , Sterck Elisabeth , de Vos Henk
Published: September 2010

Both humans and group-living animals associate and behave affiliatively more with some individuals than others. Human friendship has long been acknowledged, and recently scientists studying animal behaviour have started using the term friendship for close social associates in animals. Yet, while biologists describe friends as social tools to enhance fitness, social scientists describe human friendship as unconditional. We investigate whether these different descriptions reflect true differences in human friendship and animal close social associations or are a by-product of different research approaches: namely social scientists focussing on proximate and biologists on ultimate explanations. We first stress the importance of similar measures to determine close social associations, thereafter examine their ultimate benefits and proximate motivations, and discuss the latest findings on the central-neural regulation of social bonds. We conclude that both human friendship and animal close social associations are ultimately beneficial. On the proximate level, motivations for friendship in humans and for close social associations in animals are not necessarily based on benefits and are often unconditional. Moreover, humans share with many animals a similar physiological basis of sociality. Therefore, biologists and social scientist describe the same phenomenon, and the use of the term friendship for animals seems justified.
Calvin and the Quest for Christian Unity: An Unexpected Legacy
Authors: Cornick David
Published: September 2010

The paper argues that Calvin's reputation hides his work for the unity of the church. His mature ecclesiology was a thoughtful analysis of the catholicity of the church, and as an ecclesiastical statesman he sought to establish bonds of unity where he was able. His legacy could be of contemporary value in his Christocentrism, his lack of dogmatism about church order and his faithful tenacity.
Calvin's Theological Legacy
Authors: Fergusson David
Published: September 2010

Often caricatured for its rigidity, harshness and hostility to the arts, Calvinism has suffered from frequent misrepresentation, not least in Scotland. In particular, the identification of Calvin's theology with double predestination and religious intolerance present formidable difficulties for a contemporary appropriation of his work. While adopting a critical approach to key aspects of Calvin's thought, this essay nevertheless seeks to understand and to recover other important features of his life and work including his rhetorical strategy, the concept of divine accommodation, and his approach to church, sacraments and ministry which remains an important ecumenical resource.
Calvin's Influence on the Theology of the English Reformation
Authors: Davie Martin
Published: September 2010

This paper traces the influence of John Calvin on the English Reformation from the time of the breach with Rome under Henry VIII until the great ejection of dissenting puritan clergy from the ministry of the Church of England in 1662. It argues that Calvin's teaching only began to have an impact on the English Reformation during the reign of Elizabeth I and that although his theology had a widespread impact on both individuals and groups within the Church of England it never shaped the Church's official doctrine, liturgy or pattern of ministry, although it seemed likely that this would be the case at the time of the Westminster Assembly in the 1640s. It also raises the question of whether Calvin sought episcopacy from the Church of England in the reign of Edward VI.
Melancholy and Modernity: Dovid Bergelson’s Nokh Alemen
Authors: Banki Luisa
Published: September 2010

This article provides an analysis of the modernist qualities inherent in Dovid Bergelson’s first novel, Nokh alemen, which is read as an account of the difficult transition from tradition to modernity. This transition is described as painful, promising and impossible. The objective will be the investigation of this inability to enter into modernity, an inability that shall be viewed as a manifestation of a deeper structural inhibition that can be understood and analysed by reference to melancholia. Enlisting psychoanalytic as well as literary theoretical concepts, melancholia shall be read less as a phase that the protagonist is somehow going through and more as a fundamental psychic condition, permeating the novel as a whole. Taking into account the pervasive phenomenon of the struggle of tradition and modernity, Bergelson’s creative production, voicing and commenting on a “historic melancholia,” is not only about melancholia in its mimetic representations but also in its intellectual and historical Sitz im Leben.
Prefeeding With ω‐3 Fatty Acids Suppresses Inflammation Following Hemorrhagic Shock
Authors: Yang Rongjie , Harris William S. , Vernon Katherine , Thomas Ann M. , Qureshi Nilofer , Morrison David C. , Van Way Charles W.
Published: September 2010

Background: Hemorrhagic shock followed by resuscitation stimulates an inflammatory response. This study tests the hypothesis that prefeeding with fish oil rich in ω‐3 fatty acids (FAs) will attenuate that response. Methods: Male Sprague‐Dawley rats (n = 60; 350 ± 30 g) were randomly but unequally assigned to 3 groups: sham (n = 12), control (n = 24), and fish oil (n = 24). In the fish oil group, rat chow was supplemented with fish oil (600 mg/kg/d, 25% ω‐3 FA). Control and sham group diets were supplemented with corn oil. Under fluothane, hemorrhagic shock was induced, and arterial pressure was maintained at 25 to 30 mm Hg for 30 minutes. Resuscitation was carried out by giving 21 mL/kg lactated Ringer's solution and returning shed blood to the animal. Half of each group was killed at 30 minutes and at 4 hours postresuscitation. Liver samples were assayed for indicators of inflammation and heat shock protein 25 (Hsp25). Lung edema was measured. Results: All animals survived. At 30 minutes postresuscitation, expression of mRNA for inducible nitric oxide synthase (iNOS) was significantly elevated in the control group but normal in the fish oil group. At 4 hours, expression of mRNA for Hsp25 was significantly increased in the fish oil group. Lung edema index was significantly lower in the fish oil group than in either sham or control groups. Conclusions: Fish oil prefeeding in a rodent model of hemorrhagic shock was associated with increased liver mRNA expression of Hsp25, reduced liver mRNA expression of iNOS, and decreased lung edema. These findings support the validity of the study hypothesis.
Dysfunction of the heme recycling system in heme oxygenase 1–deficient mice: effects on macrophage viability and tissue iron distribution
Authors: Kovtunovych Gennadiy , Eckhaus Michael A. , Ghosh Manik C. , Ollivierre-Wilson Hayden , Rouault Tracey A.
Published: September 2010

To better understand the tissue iron overload and anemia previously reported in a human patient and mice that lack heme oxygenase-1 (HO-1), we studied iron distribution and pathology in HO-1(Hmox1)−/− mice. We found that resident splenic and liver macrophages were mostly absent in HO-1−/− mice. Erythrophagocytosis caused the death of HO-1−/− macrophages in in vitro experiments, supporting the hypothesis that HO-1−/− macrophages died of exposure to heme released on erythrophagocytosis. Rupture of HO-1−/− macrophages in vivo and release of nonmetabolized heme probably caused tissue inflammation. In the spleen, initial splenic enlargement progressed to red pulp fibrosis, atrophy, and functional hyposplenism in older mice, recapitulating the asplenia of an HO-1–deficient patient. We postulate that the failure of tissue macrophages to remove senescent erythrocytes led to intravascular hemolysis and increased expression of the heme and hemoglobin scavenger proteins, hemopexin and haptoglobin. Lack of macrophages expressing the haptoglobin receptor, CD163, diminished the ability of haptoglobin to neutralize circulating hemoglobin, and iron overload occurred in kidney proximal tubules, which were able to catabolize heme with HO-2. Thus, in HO-1−/− mammals, the reduced function and viability of erythrophagocytosing macrophages are the main causes of tissue damage and iron redistribution.
8-Aminoadenosine inhibits Akt/mTOR and Erk signaling in mantle cell lymphoma
Authors: Dennison Jennifer B. , Shanmugam Mala , Ayres Mary L. , Qian Jun , Krett Nancy L. , Medeiros L. Jeffrey , Neelapu Sattva S. , Rosen Steven T. , Gandhi Varsha
Published: September 2010

8-Aminoadenosine (8-NH2-Ado), a ribosyl nucleoside analog, in preclinical models of multiple myeloma inhibits phosphorylation of proteins in multiple growth and survival pathways, including Akt. Given that Akt controls the activity of mammalian target of rapamycin (mTOR), we hypothesized that 8-NH2-Ado would be active in mantle cell lymphoma (MCL), a hematological malignancy clinically responsive to mTOR inhibitors. In the current study, the preclinical efficacy of 8-NH2-Ado and its resulting effects on Akt/mTOR and extracellular-signal–regulated kinase signaling were evaluated using 4 MCL cell lines, primary MCL cells, and normal lymphocytes from healthy donors. For all MCL cell lines, 8-NH2-Ado inhibited growth and promoted cell death as shown by reduction of thymidine incorporation, loss of mitochondrial membrane potential, and poly (adenosine diphosphate-ribose) polymerase cleavage. The efficacy of 8-NH2-Ado was highly associated with intracellular accumulation of 8-NH2-adenosine triphosphate (ATP) and loss of endogenous ATP. Formation of 8-NH2-ATP was also associated with inhibition of transcription and translation accompanied by loss of phosphorylated (p-)Akt, p-mTOR, p-Erk1/2, p-phosphoprotein (p)38, p-S6, and p-4E-binding protein 1. While normal lymphocytes accumulated 8-NH2-ATP but maintained their viability with 8-NH2-Ado treatment, primary lymphoma cells accumulated higher concentrations of 8-NH2-ATP, had increased loss of ATP, and underwent apoptosis. We conclude that 8-NH2-Ado is efficacious in preclinical models of MCL and inhibits signaling of Akt/mTOR and Erk pathways.
Inheritance of central neuroanatomy and physiology related to pheromone preference in the male European corn borer
Authors: Kárpáti Zsolt , Olsson Shannon , Hansson Bill S , Dekker Teun
Published: September 2010

Background

The European corn borer (ECB), Ostrinia nubilalis, is a textbook example of pheromone polymorphism. Males of the two strains (Z and E) prefer opposite ratios of the two pheromone components, Z11- and E11-tetradecenyl acetate, with a sex-linked factor underlying this difference in preference. The male antennal lobes of the two strains contain a pheromone sensitive macroglomerular complex (MGC) that is identical in morphology, but reversed in functional topology. However, hybrids prefer intermediate ratios. How a topological arrangement of two glomeruli can accommodate for an intermediate preference was unclear. Therefore we studied the neurophysiology of hybrids and paternal backcrosses to see which factors correlated with male behavior.

Results

Projection neuron (PN) recordings and stainings in hybrids and backcrosses show a dominance of the E-type MGC topology, notwithstanding their intermediate preference. Apparently, the topological arrangement of glomeruli does not directly dictate preference. However, two other factors did correlated very well with preference. First, volumetric measurements of MGC glomeruli demonstrate that, whereas in the parental strains the medial MGC glomerulus is more than 2 times larger than the lateral, in hybrids they are intermediate between the parents, i.e. equally sized. Paternal backcrosses showed that the volume ratio is sex-linked and co-dominant. Second, we measured the summed potential difference of the antennae in response to pheromone stimulation using electroantennogram recordings (EAG). Z-strain antennae responded 2.5 times stronger to Z11 than to E11-14:OAc, whereas in E-strain antennae the ratio was approximately equal. Hybrid responses were intermediate to the parents, and also here the antennal response of the paternal backcrosses followed a pattern similar to the behavioral phenotype. We found no differences in frequency and types of projection and local interneurons encountered between the two strains and their hybrids.

Conclusions

Male pheromone preference in the ECB strains serves as a strong prezygotic reproductive isolation mechanism, and has contributed to population divergence in the field. Our results demonstrate that male pheromone preference is not directly affected by the topological arrangement of olfactory glomeruli itself, but that male preference may instead be mediated by an antennal factor, which causes the MGC glomeruli to be differentially sized. We postulate that this factor affects readout of blend information from the MGC. The results are an illustration of how pheromone preference may be 'spelled out' in the ALs, and how evolution may modulate this.
Probing the pan-genome of Listeria monocytogenes: new insights into intraspecific niche expansion and genomic diversification
Authors: Deng Xiangyu , Phillippy Adam M , Li Zengxin , Salzberg Steven L , Zhang Wei
Published: September 2010

Background

Bacterial pathogens often show significant intraspecific variations in ecological fitness, host preference and pathogenic potential to cause infectious disease. The species ofListeria monocytogenes, a facultative intracellular pathogen and the causative agent of human listeriosis, consists of at least three distinct genetic lineages. Two of these lineages predominantly cause human sporadic and epidemic infections, whereas the third lineage has never been implicated in human disease outbreaks despite its overall conservation of many known virulence factors.

Results

Here we compare the genomes of 26L. monocytogenesstrains representing the three lineages based on bothin silicocomparative genomic analysis and high-density, pan-genomic DNA array hybridizations. We uncover 86 genes and 8 small regulatory RNAs that likely makeL. monocytogeneslineages differ in carbohydrate utilization and stress resistance during their residence in natural habitats and passage through the host gastrointestinal tract. We also identify 2,330 to 2,456 core genes that define this species along with an open pan-genome pool that contains more than 4,052 genes. Phylogenomic reconstructions based on 3,560 homologous groups allowed robust estimation of phylogenetic relatedness amongL. monocytogenesstrains.

Conclusions

Our pan-genome approach enables accurate co-analysis of DNA sequence and hybridization array data for both core gene estimation and phylogenomics. Application of our method to the pan-genome ofL. monocytogenessheds new insights into the intraspecific niche expansion and evolution of this important foodborne pathogen.
Global regulation of gene expression in response to cysteine availability in Clostridium perfringens
Authors: André Gaelle , Haudecoeur Elise , Monot Marc , Ohtani Kaori , Shimizu Tohru , Dupuy Bruno , Martin-Verstraete Isabelle
Published: September 2010

Background

Cysteine has a crucial role in cellular physiology and its synthesis is tightly controlled due to its reactivity. However, little is known about the sulfur metabolism and its regulation in clostridia compared with other firmicutes. In Clostridium perfringens, the two-component system, VirR/VirS, controls the expression of the ubiG operon involved in methionine to cysteine conversion in addition to the expression of several toxin genes. The existence of links between the C. perfringens virulence regulon and sulfur metabolism prompted us to analyze this metabolism in more detail.

Results

We first performed a tentative reconstruction of sulfur metabolism in C. perfringens and correlated these data with the growth of strain 13 in the presence of various sulfur sources. Surprisingly, C. perfringens can convert cysteine to methionine by an atypical still uncharacterized pathway. We further compared the expression profiles of strain 13 after growth in the presence of cystine or homocysteine that corresponds to conditions of cysteine depletion. Among the 177 genes differentially expressed, we found genes involved in sulfur metabolism and controlled by premature termination of transcription via a cysteine specific T-box system (cysK-cysE, cysP1 and cysP2) or an S-box riboswitch (metK and metT). We also showed that the ubiG operon was submitted to a triple regulation by cysteine availability via a T-box system, by the VirR/VirS system via the VR-RNA and by the VirX regulatory RNA.

In addition, we found that expression of pfoA (theta-toxin), nagL (one of the five genes encoding hyaluronidases) and genes involved in the maintenance of cell redox status was differentially expressed in response to cysteine availability. Finally, we showed that the expression of genes involved in [Fe-S] clusters biogenesis and of the ldh gene encoding the lactate dehydrogenase was induced during cysteine limitation.

Conclusion

Several key functions for the cellular physiology of this anaerobic bacterium were controlled in response to cysteine availability. While most of the genes involved in sulfur metabolism are regulated by premature termination of transcription, other still uncharacterized mechanisms of regulation participated in the induction of gene expression during cysteine starvation.
The GPIIIA PlA2 polymorphism is associated with an increased risk of cardiovascular adverse events
Authors: Galasso Gennaro , Santulli Gaetano , Piscione Federico , De Rosa Roberta , Trimarco Valentina , Piccolo Raffaele , Cassese Salvatore , Iaccarino Guido , Trimarco Bruno , Chiariello Massimo
Published: September 2010

Background

The clinical impact of PlA2 polymorphism has been investigated in several diseases, but the definition of its specific role on thrombotic cardiovascular complications has been challenging. We aimed to explore the effect of PlA2 polymorphism on outcome in patients with atherosclerosis.

Methods

We studied 400 consecutive patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention. A replication study was conducted in 74 hypertensive patients with cerebrovascular events while a group of 100 healthy subjects was included as control population. PlA genotype was determined by PCR-RFLP on genomic DNA from peripheral blood cells. Major adverse cardiac events (MACE), were considered as end points, and recorded at a mean follow up of 24 ± 4.3 months.

Results

The frequencies of PlA2 polymorphism was similar between groups and genotype distribution was in Hardy-Weinberg equilibrium. In patients with CAD, the presence of PlA2 allele was associated with higher incidence of cardiac death (13.1% vs. 1.5%, p = 0.0001), myocardial infarction (10.7% vs. 2.6%, p = 0.004) and needs of new revascularization (34.8% vs. 17.7%, p = 0.010). Accordingly, the Kaplan-Meier analysis for event free survival in patients harboring the PlA2 allele showed worse long-term outcome for these patients (p = 0.015). Cox regression analysis identified the presence of PlA2 as an independent predictor of cardiac death (OR: 9.594, 95% CI: 2.6 to 35.3, p = 0.002) and overall MACE (OR: 1.829, 95% CI: 1.054 to 3.176, p = 0.032). In the replication study, the PlA2 polymorphism increased the risk of stroke (OR: 4.1, 95% CI: 1.63-12.4, p = 0.02) over TIA and was identified as an independent risk factor for stroke (B:-1.39; Wald: 7.15; p = 0.001).

Conclusions

Our study demonstrates that in patients with severe atherosclerosis the presence of PlA2 allele is associated with thrombotic cardiovascular complications.
Prevalent HBV point mutations and mutation combinations at BCP/preC region and their association with liver disease progression
Authors: Zhang Dake , Ma Sufang , Zhang Xin , Zhao Hanqing , Ding Huiguo , Zeng Changqing
Published: September 2010

Background

Mutations in the basic core promoter (BCP) and its adjacent precore (preC) region in HBV genome are common in chronic hepatitis B patients. However, the patterns of mutation combinations in these two regions during chronic infection are less understood. This study focused on single base mutations in BCP and preC region and the multi-mutation patterns observed in chronic HBV infection patients.

Methods

Total 192 blood samples of chronic HBV infection patients were included. Direct PCR sequencing on the target region of HBV genome was successfully conducted in 157 samples. The rest 35 samples were analyzed by clone sequencing. Only the nucleotide substitutions with their frequencies no less than 10% were included in multi-mutation analysis with the exception for the polymorphic sites between genotypes B and C.

Results

Five high frequency mutations (≥10%) were found in BCP and preC region. Thirteen types of multi-mutations in one fragment were observed, among which 3 types were common combinations (≥5%). The top three multi-mutations were A1762T/G1764A (36%), A1762T/G1764A/G1896A (11%) and T1753(A/C)/A1762T/G1764A/G1896A (8%). Patients with multi-mutations in viral genomes (≥3) were more likely to have liver cirrhosis or hepatocellular carcinoma (OR = 3.1, 95% CI: 1.6-6.0, P = 0.001). G1896A mutation seemed to be involved in liver disease progression independent of the patient age (OR = 3.6, 95% CI: 1.5-8.6; P = 0.004). In addition, patients with more viral mutations detected (≥3) were more likely to be HBeAg negative (OR = 2.7, 95% CI: 1.1-6.4; P = 0.027). Moreover, G1776A mutation was shown to contribute to HBeAg negativity in our study (OR = 8.6, 95% CI: 1.2-44.9; P = 0.01).

Conclusions

Patients with advanced liver diseases and with HBeAg negativity more likely have multi-mutations in HBV genomes but with different mutation combination patterns. G1896A mutation appears to be independent of infection history.
Effects of antibacterial mineral leachates on the cellular ultrastructure, morphology, and membrane integrity of Escherichia coli and methicillin-resistant Staphylococcus aureus
Authors: Otto Caitlin C , Cunningham Tanya M , Hansen Michael R , Haydel Shelley E
Published: September 2010

Background

We have previously identified two mineral mixtures, CB07 and BY07, and their respective aqueous leachates that exhibit in vitro antibacterial activity against a broad spectrum of pathogens. The present study assesses cellular ultrastructure and membrane integrity of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli after exposure to CB07 and BY07 aqueous leachates.

Methods

We used scanning and transmission electron microscopy to evaluate E. coli and MRSA ultrastructure and morphology following exposure to antibacterial leachates. Additionally, we employed Bac light LIVE/DEAD staining and flow cytometry to investigate the cellular membrane as a possible target for antibacterial activity.

Results

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging of E. coli and MRSA revealed intact cells following exposure to antibacterial mineral leachates. TEM images of MRSA showed disruption of the cytoplasmic contents, distorted cell shape, irregular membranes, and distorted septa of dividing cells. TEM images of E. coli exposed to leachates exhibited different patterns of cytoplasmic condensation with respect to the controls and no apparent change in cell envelope structure. Although bactericidal activity of the leachates occurs more rapidly in E. coli than in MRSA, LIVE/DEAD staining demonstrated that the membrane of E. coli remains intact, while the MRSA membrane is permeabilized following exposure to the leachates.

Conclusions

These data suggest that the leachate antibacterial mechanism of action differs for Gram-positive and Gram-negative organisms. Upon antibacterial mineral leachate exposure, structural integrity is retained, however, compromised membrane integrity accounts for bactericidal activity in Gram-positive, but not in Gram-negative cells.
FATS is a transcriptional target of p53 and associated with antitumor activity
Authors: Zhang Xifeng , Zhang Qian , Zhang Jun , Qiu Li , Yan Shuang-shuang , Feng Juling , Sun Yan , Huang Xingxu , Lu Karen H , Li Zheng
Published: September 2010

Frequent mutations of p53 in human cancers exemplify its crucial role as a tumor suppressor transcription factor, and p21, a transcriptional target of p53, plays a central role in surveillance of cell-cycle checkpoints. Our previous study has shown that FATS stabilize p21 to preserve genome integrity. In this study we identified a novel transcript variant of FATS (GenBank: GQ499374) through screening a cDNA library from mouse testis, which uncovered the promoter region of mouse FATS. Mouse FATS was highly expressed in testis. The p53-responsive elements existed in proximal region of both mouse and human FATS promoters. Functional study indicated that the transcription of FATS gene was activated by p53, whereas such effect was abolished by site-directed mutagenesis in the p53-RE of FATS promoter. Furthermore, the expression of FATS increased upon DNA damage in a p53-dependent manner. FATS expression was silent or downregulated in human cancers, and overexpression of FATS suppressed tumorigenicity in vivo independently of p53. Our results reveal FATS as a p53-regulated gene to monitor genomic stability.
Phosphorylation of HOX11/TLX1 on Threonine-247 during mitosis modulates expression of cyclin B1
Authors: Chen Edwin , Huang Xiaoyong , Zheng Yanzhen , Li You-Jun , Chesney Alden , Ben-David Yaacov , Yang Eric , Hough Margaret R
Published: September 2010

Background

The HOX11/TLX1 (hereafter referred to as HOX11) homeobox gene was originally identified at a t(10;14)(q24;q11) translocation breakpoint, a chromosomal abnormality observed in 5-7% of T cell acute lymphoblastic leukemias (T-ALLs). We previously reported a predisposition to aberrant spindle assembly checkpoint arrest and heightened incidences of chromosome missegregation in HOX11-overexpressing B lymphocytes following exposure to spindle poisons. The purpose of the current study was to evaluate cell cycle specific expression of HOX11.

Results

Cell cycle specific expression studies revealed a phosphorylated form of HOX11 detectable only in the mitotic fraction of cells after treatment with inhibitors to arrest cells at different stages of the cell cycle. Mutational analyses revealed phosphorylation on threonine-247 (Thr247), a conserved amino acid that defines the HOX11 gene family and is integral for the association with DNA binding elements. The effect of HOX11 phosphorylation on its ability to modulate expression of the downstream target, cyclin B1, was tested. A HOX11 mutant in which Thr247 was substituted with glutamic acid (HOX11 T247E), thereby mimicking a constitutively phosphorylated HOX11 isoform, was unable to bind the cyclin B1 promoter or enhance levels of the cyclin B1 protein. Expression of the wildtype HOX11 was associated with accelerated progression through the G2/M phase of the cell cycle, impaired synchronization in prometaphase and reduced apoptosis whereas expression of the HOX11 T247E mutant restored cell cycle kinetics, the spindle checkpoint and apoptosis.

Conclusions

Our results demonstrate that the transcriptional activity of HOX11 is regulated by phosphorylation of Thr247 in a cell cycle-specific manner and that this phosphorylation modulates the expression of the target gene, cyclin B1. Since it is likely that Thr247 phosphorylation regulates DNA binding activity to multiple HOX11 target sequences, it is conceivable that phosphorylation functions to regulate the expression of HOX11 target genes involved in the control of the mitotic spindle checkpoint.
Phase I clinical trial of the vaccination for the patients with metastatic melanoma using gp100-derived epitope peptide restricted to HLA-A*2402
Authors: Baba Toshiyuki , Sato-Matsushita Marimo , Kanamoto Akira , Itoh Akihiko , Oyaizu Naoki , Inoue Yusuke , Kawakami Yutaka , Tahara Hideaki
Published: September 2010

Background

The tumor associated antigen (TAA) gp100 was one of the first identified and has been used in clinical trials to treat melanoma patients. However, the gp100 epitope peptide restricted to HLA-A*2402 has not been extensively examined clinically due to the ethnic variations. Since it is the most common HLA Class I allele in the Japanese population, we performed a phase I clinical trial of cancer vaccination using the HLA-A*2402 gp100 peptide to treat patients with metastatic melanoma.

Methods

The phase I clinical protocol to test a HLA-A*2402 gp100 peptide-based cancer vaccine was designed to evaluate safety as the primary endpoint and was approved by The University of Tokyo Institutional Review Board. Information related to the immunologic and antitumor responses were also collected as secondary endpoints. Patients that were HLA-A*2402 positive with stage IV melanoma were enrolled according to the criteria set by the protocol and immunized with a vaccine consisting of epitope peptide (VYFFLPDHL, gp100-in4) emulsified with incomplete Freund's adjuvant (IFA) for the total of 4 times with two week intervals. Prior to each vaccination, peripheral blood mononuclear cells (PBMCs) were separated from the blood and stored at -80°C. The stored PBMCs were thawed and examined for the frequency of the peptide specific T lymphocytes by IFN-γ- ELISPOT and MHC-Dextramer assays.

Results

No related adverse events greater than grade I were observed in the six patients enrolled in this study. No clinical responses were observed in the enrolled patients although vitiligo was observed after the vaccination in two patients. Promotion of peptide specific immune responses was observed in four patients with ELISPOT assay. Furthermore, a significant increase of CD8+gp100-in4+CTLs was observed in all patients using the MHC-Dextramer assay. Cytotoxic T lymphocytes (CTLs) clones specific to gp100-in4 were successfully established from the PBMC of some patients and these CTL clones were capable of lysing the melanoma cell line, 888 mel, which endogenously expresses HLA-restricted gp100-in4.

Conclusion

Our results suggest this HLA-restricted gp100-in4 peptide vaccination protocol was well-tolerated and can induce antigen-specific T-cell responses in multiple patients. Although no objective anti-tumor effects were observed, the effectiveness of this approach can be enhanced with the appropriate modifications.
A role for the histone deacetylase HDAC4 in the life-cycle of HIV-1-based vectors
Authors: Smith Johanna A , Yeung Jennifer , Kao Gary D , Daniel René
Published: September 2010

HIV-1 integration is mediated by the HIV-1 integrase protein, which joins 3'-ends of viral DNA to host cell DNA. To complete the integration process, HIV-1 DNA has to be joined to host cell DNA also at the 5'-ends. This process is called post-integration repair (PIR). Integration and PIR involve a number of cellular co-factors. These proteins exhibit different degrees of involvement in integration and/or PIR. Some are required for efficient integration or PIR. On the other hand, some reduce the efficiency of integration. Finally, some are involved in integration site selection. We have studied the role of the histone deacetylase HDAC4 in these processes. HDAC4 was demonstrated to play a role in both cellular double-strand DNA break repair and transcriptional regulation. We observed that HDAC4 associates with viral DNA in an integrase-dependent manner. Moreover, infection with HIV-1-based vectors induces foci of the HDAC4 protein. The related histone deacetylases, HDAC2 and HDAC6, failed to associate with viral DNA after infection. These data suggest that HDAC4 accumulates at integration sites. Finally, overexpression studies with HDAC4 mutants suggest that HDAC4 may be required for efficient transduction by HIV-1-based vectors in cells that are deficient in other DNA repair proteins. We conclude that HDAC4 is likely involved in PIR.
Comparison of human papillomavirus detection between freshly frozen tissue and paraffin embedded tissue of invasive cervical cancer
Authors: Odida Michael , de Sanjose Silvia , Sandin Sven , Quiros Beatriz , Alemany Laia , Lloveras Belen , Quint Wim , Kleter Bernhard , Alejo Maria , van Doorn Leen-Jan , Weiderpass Elisabete
Published: September 2010

Background

Human Papillomavirus (HPV) detection results comparing paraffin embedded cervical tissue and other cervical specimens have been done with varying degrees of agreement. However, studies comparing freshly frozen specimens and paraffin embedded specimens of invasive cervical carcinomas are lacking. The aim of the study was to compare HPV detection using SPF10 broad-spectrum primers PCR followed by DEIA and genotyping by LiPA25 (version 1) between freshly frozen cervical tissue samples and paraffin embedded blocks of cervical tissue from the same patient. There were 171 pairs of paraffin embedded and freshly frozen samples analyzed from cervical carcinoma cases from Kampala, Uganda.

Results

88.9% (95% CI: 83.2%-93.2%) of paraffin embedded samples were HPV positive compared with 90.1% (95% CI: 84.6%-94.1%) of freshly frozen samples, giving an overall agreement in HPV detection between fresh tissue and paraffin embedded tissue at 86.0% (95% CI: 79.8%-90.8%). Although the proportion of HPV positive cases in freshly frozen tissue was higher than those in paraffin blocks, the difference was not statistically significant (p > 0.05). In both types of tissues, single HPV infections were predominant, with HPV16 accounting for 47% of positive cases. Comparison in the overall agreement, taking into accounts not only positivity in general, but also HPV types, showed a 65% agreement (complete agreement of 59.7%, partial agreement of 5.3%) and complete disagreement of 35.0%. HPV detection in squamous cell carcinomas (SCC) and adenocarcinomas (ADC) was similar in fresh tissue or paraffin blocks (p ≥ 0.05).

p16 immunostaining in samples that had at least one HPV negative results showed that 24 out of 25 cases had an over-expressed pattern.

Conclusions

HPV DNA detection was lower among ADC as compared to SCC. However, such differences were minimized when additional p16 testing was added, suggesting that the technical issues may largely explain the HPV negative cases.
A case-controlled validation study of a blood-based seven-gene biomarker panel for colorectal cancer in Malaysia
Authors: Yip Kok-Thye , Das Prashanta K , Suria David , Lim Chun-Ren , Ng Guey-Hooi , Liew Choong-Chin
Published: September 2010

Background

Colorectal cancer (CRC) screening is key to CRC prevention and mortality reduction, but patient compliance with CRC screening is low. We previously reported a blood-based test for CRC that utilizes a seven-gene panel of biomarkers. The test is currently utilized clinically in North America for CRC risk stratification in the average-risk North American population in order to improve screening compliance and to enhance clinical decision making.

Methods

In this study, conducted in Malaysia, we evaluated the seven-gene biomarker panel validated in a North American population using blood samples collected from local patients. The panel employs quantitative RT-PCR (qRT-PCR) to analyze gene expression of the seven biomarkers (ANXA3, CLEC4D, TNFAIP6, LMNB1, PRRG4, VNN1 and IL2RB) that are differentially expressed in CRC patients as compared with controls. Blood samples from 210 patients (99 CRC and 111 controls) were collected, and total blood RNA was isolated and subjected to quantitative RT-PCR and data analysis.

Results

The logistic regression analysis of seven-gene panel has an area under the curve (AUC) of 0.76 (95% confidence interval: 0.70 to 0.82), 77% specificity, 61% sensitivity and 70% accuracy, comparable to the data obtained from the North American investigation of the same biomarker panel.

Conclusions

Our results independently confirm the results of the study conducted in North America and demonstrate the ability of the seven biomarker panel to discriminate CRC from controls in blood samples drawn from a Malaysian population.