bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of the deflections of a catheter steered using a magnetic resonance imaging system
Authors: Gosselin Frédérick P. , Lalande Viviane , Martel Sylvain
Published: August 2011

Purpose:

The authors quantify the deflections of a catheter and a guidewire in MR setting with different designs of ferromagnetic tips and a system of high gradient coils which can generate gradients, and thus forces, 20 times larger than a conventional scanner.

Methods:

Different designs of catheter tips are experimentally tested in an effort to maximize the deflections. One to two ferromagnetic spheres are attached at the distal tip of the catheter (or guidewire) with different spacing between the spheres. The effect of dipole–dipole interaction on the steering of the catheter is studied through experimentation and theoretical modeling. The effect of using many spheres on the artefact generated in fast imaging sequences is also investigated.

Results:

A catheter and a guidewire are successfully steered by applying magnetic gradients inside a magnetic resonance scanner. More ferromagnetic material allows for larger magnetic forces, however, the use of two ferromagnetic spheres introduces undesired dipole–dipole interactions. Two ferromagnetic spheres generate a single larger artefact as they are close together.

Conclusions:

By varying the distance between the two ferromagnetic spheres, a balance can be struck between the need to minimize the size of the tip and the undesirable dipole–dipole interaction.
Type 1 Diabetes Immunotherapy: Is the Glass Half Empty or Half Full?
Authors: Herold Kevan C. , Bluestone Jeffrey A.
Published: August 2011

The islet cell preservation observed in immunotherapy clinical trials should motivate the type 1 diabetes community.
Cryptococcal Titan Cell Formation Is Regulated by G-Protein Signaling in Response to Multiple Stimuli
Authors: Okagaki Laura H. , Wang Yina , Ballou Elizabeth R. , O'Meara Teresa R. , Bahn Yong-Sun , Alspaugh J. Andrew , Xue Chaoyang , Nielsen Kirsten
Published: August 2011

The titan cell is a recently described morphological form of the pathogenic fungus
Cryptococcus neoformans
. Occurring during the earliest stages of lung infection, titan cells are 5 to 10 times larger than the normal yeast-like cells, thereby resisting engulfment by lung phagocytes and favoring the persistence of infection. These enlarged cells exhibit an altered capsule structure, a thickened cell wall, increased ploidy, and resistance to nitrosative and oxidative stresses. We demonstrate that two G-protein-coupled receptors are important for induction of the titan cell phenotype: the Ste3
a
pheromone receptor (in mating type
a
cells) and the Gpr5 protein. Both receptors control titan cell formation through elements of the cyclic AMP (cAMP)/protein kinase A (PKA) pathway. This conserved signaling pathway, in turn, mediates its effect on titan cells through the PKA-regulated Rim101 transcription factor. Additional downstream effectors required for titan cell formation include the G
1
cyclin Pcl103, the Rho104 GTPase, and two GTPase-activating proteins, Gap1 and Cnc1560. These observations support developing models in which the PKA signaling pathway coordinately regulates many virulence-associated phenotypes in diverse human pathogens.
Frequent Mutations within the Genomic Magnetosome Island of Magnetospirillum gryphiswaldense Are Mediated by RecA
Authors: Kolinko Isabel , Jogler Christian , Katzmann Emanuel , Schüler Dirk
Published: August 2011

Genes for magnetosome formation in magnetotactic bacteria are clustered in large genomic magnetosome islands (MAI). Spontaneous deletions and rearrangements were frequently observed within these regions upon metabolic stress. This instability was speculated to be due to RecA-dependent homologous recombination between the numerous sequence repeats present within the MAI. Here we show that a RecA-deficient strain of
Magnetospirillum gryphiswaldense
(IK-1) no longer exhibits genetic instability of magnetosome formation. Strain IK-1 displayed higher sensitivity to oxygen and UV irradiation. Furthermore, the lack of RecA abolished allelic exchange in the mutant. Cells of strain IK-1 displayed a slightly altered (i.e., more elongated) morphology, whereas the absence of RecA did not affect the ability to synthesize wild-type-like magnetosomes. Our data provide evidence that the observed genetic instability of magnetosome formation in the wild type is due predominantly to RecA-mediated recombination. In addition, increased genetic stability could make strain IK-1 a useful tool for the expression of genes and further genetic engineering, as well as for biotechnological production of bacterial magnetosomes.
Components of the
Rv0081-Rv0088
Locus, Which Encodes a Predicted Formate Hydrogenlyase Complex, Are Coregulated by Rv0081, MprA, and DosR in Mycobacterium tuberculosis
Authors: He Hongjun , Bretl Daniel J. , Penoske Renee M. , Anderson David M. , Zahrt Thomas C.
Published: August 2011

Mycobacterium tuberculosis
, the etiological agent of tuberculosis, remains a significant cause of morbidity and mortality throughout the world despite a vaccine and cost-effective antibiotics. The success of this organism can be attributed, in part, to its ability to adapt to potentially harmful stress within the host and establish, maintain, and reactivate from long-term persistent infection within granulomatous structures. The DosRS-DosT/DevRS-Rv2027c, and MprAB two-component signal transduction systems have previously been implicated in aspects of persistent infection by
M. tuberculosis
and are known to be responsive to conditions likely to be found within the granuloma. Here, we describe initial characterization of a locus (
Rv0081-Rv0088
) encoding components of a predicted formate hydrogenylase enzyme complex that is directly regulated by DosR/DevR and MprA, and the product of the first gene in this operon, Rv0081. In particular, we demonstrate that Rv0081 negatively regulates its own expression and that of downstream genes by binding an inverted repeat element in its upstream region. In contrast, DosR/DevR and MprA positively regulate
Rv0081
expression by binding to recognition sequences that either partially or completely overlap that recognized by Rv0081, respectively. Expression of
Rv0081
initiates from two promoter elements; one promoter located downstream of the DosR/DevR binding site but overlapping the sequence recognized by both Rv0081 and MprA and another promoter downstream of the DosR/DevR, Rv0081, and MprA binding sites. Interestingly, Rv0081 represses
Rv0081
and downstream determinants following activation of DosRS-DosT/DevRS-Rv2027c by nitric oxide, suggesting that expression of this locus is complex and subject to multiple levels of regulation. Based on this and other published information, a model is proposed detailing
Rv0081-Rv0088
expression by these transcription factors within particular growth environments.
Localization and Assembly of the Novel Exosporium Protein BetA of Bacillus anthracis
Authors: Thompson Brian M. , Hoelscher Bryce C. , Driks Adam , Stewart George C.
Published: August 2011

The exosporium of
Bacillus anthracis
is comprised of two distinct layers: a basal layer and a hair-like nap that covers the basal layer. The hair-like nap contains the glycoproteins BclA and, most likely, BclB. BclA and BclB are directed to assemble into the exosporium by motifs in their N-terminal domains. Here, we identify a previously uncharacterized putative gene encoding this motif, which we have named
betA
(
Bacillus
exosporium-targeted protein of
B. anthracis
). Like
bclA
,
betA
encodes a putative collagenlike repeat region.
betA
is present in several genomes of exosporium-producing
Bacillus
species but, so far, not in any others. Using fluorescence microscopic localization of a BetA-enhanced green fluorescent protein (eGFP) fusion protein and immunofluorescence microscopy with anti-BetA antibodies, we showed that BetA resides in the exosporium basal layer, likely underneath BclA. BetA assembles at the spore surface at around hour 5 of sporulation and under the control of BxpB, similar to the control of deposition of BclA. We suggest a model in which BclA and BetA are incorporated into the exosporium by a mechanism that depends on their similar N termini. These data suggest that BetA is a member of a growing family of exosporium proteins that assemble under the control of targeting sequences in their N termini.
Fungal diversity in activated sludge from membrane bioreactors in Berlin
Authors: Awad Mohamed F. , Kraume M.
Published: August 2011

The objective of this study was to evaluate the occurrence of fungi in aerobic and anoxic activated sludge from membrane bioreactors. Thirty-six samples from each aerobic and anoxic activated sludge were taken from two membrane bioreactors treating domestic wastewater. Over a period of 9 months, four samples from each plant were taken per month. The samples were prepared for count and identification of fungi. Sixty species belonging to 30 genera were collected from activated sludge samples under aerobic and anoxic conditions. In terms of fungal identification, under aerobic conditions Geotrichum candidum was found at 94.4% followed by Penicillium species at 80.6%, yeasts at 75.0%, and Trichoderma species at 50.0%; under anoxic conditions G. candidum at 86.1%, yeasts at 66.6%, and Penicillium species at 61.1% were the most prevalent. The results indicate that activated sludge is a habitat for growth and sporulation of different groups of fungi, both saprophytic and pathogenic.
TRAWLING TRAFFIC UNDER ATTACK OVERCOMING DDoS ATTACKS BY TARGET-CONTROLLED TRAFFIC FILTERING
Authors: DOLEV SHLOMI , ELOVICI YUVAL , KESSELMAN ALEX , ZILBERMAN POLINA
Published: August 2011

As more and more services are provided by servers via the Internet, Denial-of-Service (DoS) attacks pose an increasing threat to the Internet community. A DoS attack overloads the target server with a large volume of adverse requests, thereby rendering the server unavailable to "well-behaved" users. In this paper, we propose two algorithms that allow attack targets to dynamically filter their incoming traffic based on a distributed policy. The proposed algorithms defend the target against DoS and distributed DoS (DDoS) attacks and simultaneously ensure that it continues to serve "well-behaved" users.

In a nutshell, a target can define a filtering policy which consists of a set of traffic classification rules and the corresponding amounts of traffic for each rule. A filtering algorithm is enforced by the ISP's routers when a target is being overloaded with traffic. The goal is to maximize the amount of filtered traffic forwarded to the target, according to the filtering policy, from the ISP.

The first proposed algorithm is a collaborative algorithm which computes and delivers to the target the best possible traffic mix in polynomial time. The second algorithm is a distributed non-collaborative algorithm for which we prove a lower bound on the worst-case performance.
SELF-STABILIZING COMPUTATION OF 3-EDGE-CONNECTED COMPONENTS
Authors: SAIFULLAH ABUSAYEED , TSIN YUNG H.
Published: August 2011

A self-stabilizing algorithm is a distributed algorithm that can start from any initial (legitimate or illegitimate) state and eventually converge to a legitimate state in finite time without being assisted by any external agent. In this paper, we propose a self-stabilizing algorithm for finding the 3-edge-connected components of an asynchronous distributed computer network. The algorithm stabilizes in O(dnΔ) rounds and every processor requires O(n log Δ) bits, where Δ(≤ n) is an upper bound on the degree of a node, d(≤ n) is the diameter of the network, and n is the total number of nodes in the network. These time and space complexity are at least a factor of n better than those of the previously best-known self-stabilizing algorithm for 3-edge-connectivity. The result of the computation is kept in a distributed fashion by assigning, upon stabilization of the algorithm, a component identifier to each processor which uniquely identifies the 3-edge-connected component to which the processor belongs. Furthermore, the algorithm is designed in such a way that its time complexity is dominated by that of the self-stabilizing depth-first search spanning tree construction in the sense that any improvement made in the latter automatically implies improvement in the time complexity of the algorithm.
AN APPLICATION OF ST-NUMBERING TO SECRET KEY AGREEMENT
Authors: MIZUKI TAKAAKI , NAKAYAMA SATORU , SONE HIDEAKI
Published: August 2011

Assume that there are players and an eavesdropper Eve, where several pairs of players have shared secret keys beforehand. We regard each player as a vertex of a graph and regard each pair of players sharing a key as an edge. Consider the case where Eve knows some of the keys according to a certain probability distribution. In this paper, applying the technique of st-numbering, we propose a protocol which allows any two designated players to agree on a secret key through such a "partially leaked key exchange graph." Our protocol is optimal in the sense that Eve's knowledge about the secret key agreed on by the two players is as small as possible.
RESIDUAL CLOSENESS OF WHEELS AND RELATED NETWORKS
Authors: AYTAÇ AYSUN , ODABAŞ ZEYNEP NIHAN
Published: August 2011

The vulnerability of a network measures the resistance of the network to disruption of operation after the failure of certain stations or communication links. If we think of a graph as modeling a network, several vulnerability measures have been used to describe the stability of networks, including connectivity, toughness, scattering number, binding number and integrity. We consider a new characteristic, residual closeness which is more sensitive than the well-known vulnerability measures. Residual closeness measures the network resistance evaluating closeness after removal of vertices or links. In this paper, closeness, vertex residual closeness (VRC) and normalized vertex residual closeness (NVRC) of wheels and some related networks namely gear and friendship graph are calculated, and exact values are obtained.
RELATIVISTIC RING MODELS
Authors: UJEVIC MAXIMILIANO , LETELIER PATRICIO S. , VOGT DANIEL
Published: August 2011

Relativistic thick ring models are constructed using previously found analytical Newtonian potential-density pairs for flat rings and toroidal structures obtained from Kuzmin–Toomre family of disks. In particular, we present systems with one ring, two rings and a disk with a ring. Also, the circular velocity of a test particle and its stability when performing circular orbits are presented in all these models. In general, we find that regions of non-stability appear between the rings when they become thinner.
EXPANSION-FREE CAVITY EVOLUTION: SOME EXACT ANALYTICAL MODELS
Authors: DI PRISCO A. , HERRERA L. , OSPINO J. , SANTOS N. O. , VIÑA-CERVANTES V. M.
Published: August 2011

We consider spherically symmetric distributions of anisotropic fluids with a central vacuum cavity, evolving under the condition of vanishing expansion scalar. Some analytical solutions are found satisfying Darmois junction conditions on both delimiting boundary surfaces, while some others require the presence of thin shells on either (or both) boundary surfaces. The solutions here obtained model the evolution of the vacuum cavity and the surrounding fluid distribution, emerging after a central explosion, thereby showing the potential of expansion–free condition for the study of that kind of problems. This study complements a previously published work where modeling of the evolution of such kind of systems was achieved through a different kinematical condition.
REGULARIZING PROPERTIES OF BROWNIAN PATHS AND A RESULT OF DAVIE
Authors: FLANDOLI FRANCO
Published: August 2011

Brownian motion regularizes ODEs, in the sense that non-well-posed ODEs become well-posed in the strong probabilitic sense by the addition of a non-degenerate noise. A version of such regularization property for single paths of Brownian motion has been given by A. M. Davie. We discuss some fragments of this deep result.
RURAL WOMEN AND ENTREPRENEURSHIP: A CASE STUDY IN HERAKLION CRETE PREFECTURE, GREECE
Authors: LASSITHIOTAKI AIKATERINI
Published: August 2011

This article investigates the entrepreneurial beliefs/attitudes, ambitions, expectations, goals and visions of rural women who choose to cooperate and found Women's Rural cooperatives in the Prefecture of Heraklion on the island of Crete. The results of a qualitative study involving a sample of eight chairwomen of rural women's established Traditional Food Production cooperatives indicated that the traditional domestic roles (housewife, mother), the low level of education, the lack of professional skills, enterprise experience and mostly the unwillingness of rural women to undertake enterprise risk, have turned them toward an enterprise model that lacks modern business methods in the use of quality control production systems, in the production of Protected Geographical Identification Goods and/or Certified Local Traditional Food and/or Organic Products, in the use of new organizing and managing technologies, in advertising and promoting products and in administrative renewal.
An empirical analysis of a testability model for object-oriented programs
Authors: Kout Aymen , Toure Fadel , Badri Mourad
Published: August 2011

We present, in this paper, a metric based testability model for object-oriented programs. The model is, in fact, an adaptation of a model pro-posed in literature for assessing the testability of object-oriented design. The study presented in this paper aims at exploring empirically the capa-bility of the model to assess testability of classes at the code level. We investigate testability from the perspective of unit testing and required testing effort. We designed an empirical study using data collected from two Java software systems for which JUnit test cases exist. To capture testability of classes in terms of required testing effort, we used different metrics to quantify the corresponding JUnit test cases. In order to eva-luate the capability of the model to predict testability of classes (charac-teristics of corresponding test classes), we used statistical tests using correlation.
Rounding coefficients and artificially underflowing terms in non-numeric expressions
Authors: Corless Robert , Postma Erik , Stoutemyer David R.
Published: August 2011

This article takes an analytical viewpoint to address the following questions:

1. How can we justifiably beautify an input or result sum of non-numeric terms that has some approximate coefficients by deleting some terms and/or rounding some coefficients to simpler floating-point or rational numbers?

2. When we add two expressions, how can we justifiably delete more non-zero result terms and/or round some result coefficients to even simpler floating-point, rational or irrational numbers?

The methods considered in this paper provide a justifiable scale-invariant way to attack these problems for subexpressions that are multivariate sums of monomials with real exponents.
Cardiac proteasome activity in muscle ring finger-1 null mice at rest and following synthetic glucocorticoid treatment
Authors: Hwee Darren T. , Gomes Aldrin V. , Bodine Sue C.
Published: August 2011

Muscle ring finger-1 (MuRF1) is a muscle-specific E3 ubiquitin ligase that has been implicated in the regulation of cardiac mass through its control of the ubiquitin proteasome system. While it has been suggested that MuRF1 is required for cardiac atrophy, a resting cardiac phenotype has not been reported in mice with a null deletion [knockout (KO)] of MuRF1. Here, we report that MuRF1 KO mice have significantly larger hearts than age-matched wild-type (WT) littermates at ≥6 mo of age and that loss of cardiac mass can occur in the absence of MuRF1. The objective of this study was to determine whether changes in proteasome activity were responsible for the cardiac phenotypes observed in MuRF1 KO mice. Cardiac function, architecture, and proteasome activity were analyzed at rest and following 28 days of dexamethasone (Dex) treatment in 6-mo-old WT and MuRF1 KO mice. Echocardiography demonstrated normal cardiac function in the enlarged hearts in MURF1 KO mice. At rest, heart mass and cardiomyocyte diameter were significantly greater in MuRF1 KO than in WT mice. The increase in cardiac size in MuRF1 KO mice was related to a decrease in proteasome activity and an increase in Akt signaling relative to WT mice. Dex treatment induced a significant loss of cardiac mass in MuRF1 KO, but not WT, mice. Furthermore, Dex treatment resulted in an increase in proteasome activity in KO, but a decrease in WT, mice. In contrast, Akt/mammalian target of rapamycin signaling decreased in MuRF1 KO mice and increased in WT mice in response to Dex treatment. These findings demonstrate that MuRF1 plays an important role in regulating cardiac size through alterations in protein turnover and that MuRF1 is not required to induce cardiac atrophy.
Mechanisms of atrial-selective block of Na+ channels by ranolazine: II. Insights from a mathematical model
Authors: Nesterenko Vladislav V. , Zygmunt Andrew C. , Rajamani Sridharan , Belardinelli Luiz , Antzelevitch Charles
Published: August 2011

Block of Na+ channel conductance by ranolazine displays marked atrial selectivity that is an order of magnitude higher that of other class I antiarrhythmic drugs. Here, we present a Markovian model of the Na+ channel gating, which includes activation-inactivation coupling, aimed at elucidating the mechanisms underlying this potent atrial selectivity of ranolazine. The model incorporates experimentally observed differences between atrial and ventricular Na+ channel gating, including a more negative position of the steady-state inactivation curve in atrial versus ventricular cells. The model assumes that ranolazine requires a hydrophilic access pathway to the channel binding site, which is modulated by both activation and inactivation gates of the channel. Kinetic rate constants were obtained using guarded receptor analysis of the use-dependent block of the fast Na+ current ( INa). The model successfully reproduces all experimentally observed phenomena, including the shift of channel availability, the sensitivity of block to holding or diastolic potential, and the preferential block of slow versus fast INa. Using atrial and ventricular action potential-shaped voltage pulses, the model confirms significantly greater use-dependent block of peak INa in atrial versus ventricular cells. The model highlights the importance of action potential prolongation and of a steeper voltage dependence of the time constant of unbinding of ranolazine from the atrial Na+ channel in the development of use-dependent INa block. Our model predictions indicate that differences in channel gating properties as well as action potential morphology between atrial and ventricular cells contribute equally to the atrial selectivity of ranolazine. The model indicates that the steep voltage dependence of ranolazine interaction with the Na+ channel at negative potentials underlies the mechanism of the predominant block of INa in atrial cells by ranolazine.
19,20-EpDPE, a bioactive CYP450 metabolite of DHA monoacyglyceride, decreases Ca2+ sensitivity in human pulmonary arteries
Authors: Morin Caroline , Fortin Samuel , Rousseau Eric
Published: August 2011

The aim of this study was to investigate the effect of docosahexaenoic acid monoacylglyceride (MAG-DHA) on human pulmonary arterial tone. Tension measurements on pulmonary arterial tissues demonstrated that MAG-DHA reduced U-46619-induced tone, which is highly sensitive to the H-1152 inhibitor. Results also showed that MAG-DHA treatments decreased RhoA activity levels, which in turn inactivated the Rho-kinase pathway, leading to a reduction in U-46619-induced Ca2+ sensitivity of permeabilized pulmonary artery smooth muscle cells. According to the mechanical responses assessing U-46619-induced Ca2+ sensitivity in the absence or presence of 3 μM MAG-DHA, MAG-DHA plus 1 μM N-methylsulfonyl-6-(2-propargyloxyphenyl) hexanamide (MS-PPOH, a cytochrome P-450 epoxygenase inhibitor) and 300 nM 19,20-epoxydocosapentaenoic acid (a cytochrome P-450 epoxygenase-dependent DHA metabolite), our data suggest that the MAG-DHA is metabolized in a bioactive epoxymetabolite. This epoxyeicosanoid in turn decreases active tone and Ca2+ sensitivity of smooth muscles cells through an inhibition of the Rho-kinase pathway. Together, these data provide primary evidence regarding the mode of action of MAG-DHA in human pulmonary arteries and suggest that this compound may be of pharmacological interest in patients with pulmonary hypertension to generate intracellular bioactive metabolites.
Lysophosphatidic acid receptor 1 modulates lipopolysaccharide-induced inflammation in alveolar epithelial cells and murine lungs
Authors: Zhao Jing , He Donghong , Su Yanlin , Berdyshev Evgeny , Chun Jerold , Natarajan Viswanathan , Zhao Yutong
Published: August 2011

Lysophosphatidic acid (LPA), a bioactive phospholipid, plays an important role in lung inflammation by inducing the release of chemokines and lipid mediators. Our previous studies have shown that LPA induces the secretion of interleukin-8 and prostaglandin E2 in lung epithelial cells. Here, we demonstrate that LPA receptors contribute to lipopolysaccharide (LPS)-induced inflammation. Pretreatment with LPA receptor antagonist Ki16425 or downregulation of LPA receptor 1 (LPA1) by small-interfering RNA (siRNA) attenuated LPS-induced phosphorylation of p38 MAPK, I-κB kinase, and I-κB in MLE12 epithelial cells. In addition, the blocking of LPA1 also suppressed LPS-induced IL-6 production. Furthermore, LPS treatment promoted interaction between LPA1 and CD14, a LPS coreceptor, in a time- and dose-dependent manner. Disruption of lipid rafts attenuated the interaction between LPA1 and CD14. Mice challenged with LPS increased plasma LPA levels and enhanced expression of LPA receptors in lung tissues. To further investigate the role of LPA receptors in LPS-induced inflammation, wild-type, or LPA1-deficient mice, or wild-type mice pretreated with Ki16425 were intratracheally challenged with LPS for 24 h. Knock down or inhibition of LPA1 decreased LPS-induced IL-6 release in bronchoalveolar lavage (BAL) fluids and infiltration of cells into alveolar space compared with wild-type mice. However, no significant differences in total protein concentration in BAL fluids were observed. These results showed that knock down or inhibition of LPA1 offered significant protection against LPS-induced lung inflammation but not against pulmonary leak as observed in the murine model for lung injury.
Increased hyaluronan fragmentation during pulmonary ischemia
Authors: Eldridge Lindsey , Moldobaeva Aigul , Wagner Elizabeth M.
Published: August 2011

Hyaluronan (HA), a glycosaminoglycan critical to the lung extracellular matrix, has been shown to dissociate into low-molecular-weight (LMW) HA fragments following exposure to injurious stimuli. In the present study we questioned whether lung HA changed during ischemia and whether changes had an effect on subsequent angiogenesis. After left pulmonary artery ligation (LPAL) in mice, we analyzed left lung homogenates immediately after the onset of ischemia (0 h) and intermittently for 14 days. The relative expression of HA synthase (HAS)1, HAS2, and HAS3 was determined by real-time RT-PCR, total HA in the lung was measured by an ELISA-like assay, gel electrophoresis was performed to determine changes in HA size distribution, and the activity of hyaluronidases was determined by zymography. A 50% increase in total HA was measured 16 h after the onset of ischemia and remained elevated for up to 7 days. Furthermore, a fourfold increase in LMW HA fragments (495–30 kDa) was observed by 4 h after LPAL. Both HAS1 and HAS2 showed increased expression 4–16 h after LPAL, yet no changes were seen in hyaluronidase activity. These results suggest that both HA fragmentation and activation of HA synthesis contribute to increased HA levels during lung ischemia. Delivery of LMW HA fragments in an in vitro tube formation assay or directly to the ischemic mouse lung in vivo both resulted in increased angiogenesis. We conclude that ischemic injury results in matrix fragmentation, which leads to stimulation of neovascularization.
Chronic intermittent hypoxia-induced vascular enlargement and VEGF upregulation in the rat carotid body is not prevented by antioxidant treatment
Authors: Rio Rodrigo Del , Muñoz Cristian , Arias Paulina , Court Felipe A. , Moya Esteban A. , Iturriaga Rodrigo
Published: August 2011

Chronic intermittent hypoxia (CIH), a characteristic of sleep obstructive apnea, enhances carotid body (CB) chemosensory responses to hypoxia, but its consequences on CB vascular area and VEGF expression are unknown. Accordingly, we studied the effect of CIH on CB volume, glomus cell numbers, blood vessel diameter and number, and VEGF immunoreactivity (VEGF-ir) in male Sprague-Dawley rats exposed to 5% O2, 12 times/h for 8 h or sham condition for 21 days. We found that CIH did not modify the CB volume or the number of glomus cells but increased VEGF-ir and enlarged the vascular area by increasing the size of the blood vessels, whereas the number of the vessels was unchanged. Because oxidative stress plays an essential role in the CIH-induced carotid chemosensory potentiation, we tested whether antioxidant treatment with ascorbic acid may impede the vascular enlargement and the VEGF upregulation. Ascorbic acid, which prevents the CB chemosensory potentiation, failed to impede the vascular enlargement and the increased VEGF-ir. Thus present results suggest that the CB vascular enlargement induced by CIH is a direct effect of intermittent hypoxia and not secondary to the oxidative stress. Accordingly, the subsequent capillary changes may be secondary to the mechanisms involved in the neural chemosensory plasticity induced by intermittent hypoxia.
Improved bioavailability of epoxyeicosatrienoic acids reduces TP-receptor agonist-induced tension in human bronchi
Authors: Senouvo Farid Yannick , Tabet Yacine , Morin Caroline , Albadine Roula , Sirois Chantal , Rousseau Eric
Published: August 2011

Epoxyeicosatrienoic acid (EET) and thromboxane A2are arachidonic acid derivatives. The former has initially been defined as an epithelium-derived hyperpolarizing factor displaying broncho-relaxing ( 4 ) and anti-inflammatory properties, as recently demonstrated ( 25 ), whereas thromboxane A2induces vaso- and bronchoconstriction upon binding to thromboxane-prostanoid (TP)-receptor. EETs, however, are quickly degraded by the soluble epoxide hydrolase (sEH) into inactive diol compounds ( 25 ). The aim of this study was to investigate the effects of 14,15-EET on TP-receptor activation in human bronchi. Tension measurements performed on native bronchi from various species, acutely treated with increasing 14,15-EET concentrations, revealed specific and concentration-dependent relationships as well as a decrease in the tension induced by 30 nM U-46619, used as a synthetic TP-receptor agonist. Interestingly, acute treatments with 3 μM N-(methylsulfonyl)-2-(2-propynyloxy)-benzenehexanamide, an epoxygenase inhibitor, which minimizes endogenous production of EET, resulted in an increased reactivity to U-46619. Furthermore, we demonstrated that chronic treatments with trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB), a sEH inhibitor, reduced human bronchi reactivity to U-46619. During our tension measurements, we also observed that human bronchi generated small-amplitude contractions; these spontaneous activities were reduced upon acute 14,15-EET treatments in the presence of t-AUCB. Altogether, these data demonstrate that endogenous and exogenous 14,15-EET could interfere with the activation of TP-receptors as well as with spontaneous oscillations in human airway smooth muscle tissues.
Physiopathology of Spine Metastasis
Authors: Maccauro Giulio , Spinelli Maria Silvia , Mauro Sigismondo , Perisano Carlo , Graci Calogero , Rosa Michele Attilio
Published: August 2011

The metastasis is the spread of cancer from one part of the body to another. Two-thirds of patients with cancer will develop bone metastasis. Breast, prostate and lung cancer are responsible for more than 80% of cases of metastatic bone disease. The spine is the most common site of bone metastasis. A spinal metastasis may cause pain, instability and neurological injuries. The diffusion through Batson venous system is the principal process of spinal metastasis, but the dissemination is possible also through arterial and lymphatic system or by contiguity. Once cancer cells have invaded the bone, they produce growth factors that stimulate osteoblastic or osteolytic activity resulting in bone remodeling with release of other growth factors that lead to a vicious cycle of bone destruction and growth of local tumour.
Measurement of Photoreceptor Layer in Glaucoma: A Spectral-Domain Optical Coherence Tomography Study
Authors: Fan Ning , Huang Nina , Lam Dennis Shun Chiu , Leung Christopher Kai-shun
Published: August 2011

Objective.To measure and compare photoreceptor layer thickness between normal and glaucomatous eyes using spectral-domain optical coherence tomography (OCT).Methods. Thirty-eight healthy normal volunteers and 47 glaucoma patients were included in the analysis. One eye from each participant was randomly selected for macula imaging by a spectral-domain OCT (3D OCT-1000, Topcon, Tokyo, Japan). The foveal and parafoveal (1.5 mm from the fovea) outer nuclear layer (ONL) and inner and outer segments (IS+OS) layer thicknesses were measured by a single masked observer. The measurements were repeated 3 times in a random sample of 30 normal eyes to determine the repeatability coefficient and intraclass correlation coefficient.Results.The measurement variabilities of photoreceptor thickness were low. The respective intraclass correlation coefficients of ONL and IS+OS thicknesses were 0.96 (95% confidence interval: 0.94–0.98) and 0.82 (95% confidence interval 0.70–0.90). While there were no differences in parafoveal ONL and IS+OS thicknesses between normal and glaucoma groups (), the foveal ONL thickness was greater in glaucomatous eyes () than in normal eyes.Conclusions.Glaucomatous damage may involve structural change in the photoreceptor layer.
Preparation of Single- and Few-Layer Graphene Sheets Using Co Deposition on SiC Substrate
Authors: Li Cun , Li Dandan , Yang Jingjing , Zeng Xiaopeng , Yuan Wenxia
Published: August 2011

Single- and few-layer graphene sheets were fabricated by selective chemical reactions between Co film and SiC substrate. A rapid cooling process was employed. The number of layers and crystallinity of graphene sheets were controlled by process parameters. The formation mechanism of graphene was highly sensitive to carbon diffusion. Free carbon precipitated and then moved across the product layer that was composed mainly of cobalt-silicides. The graphene layer formed homogeneously on the surface and then transferred to the other substrate. This could provide a method for high-quality fabrication of wafer-sized graphene sheets.
On the General Solution of the Ultrahyperbolic Bessel Operator
Authors: Damkengpan Rattapan , Nonlaopon Kamsing
Published: August 2011

We study the general solution of equation , where is the ultrahyperbolic Bessel operator iterated k‐times and is defined by , n is the dimension of , , 2vi = 2βi + 1, βi > −1/2, xi > 0 (i = 1, 2, …, n), f(x) is a given generalized function, u(x) is an unknown generalized function, k is a nonnegative integer, c is a positive constant, and .
miRNAs and Melanoma: How Are They Connected?
Authors: Cruz Adriana Taveira da , Jasiulionis Miriam Galvonas
Published: August 2011

miRNAs are non-coding RNAs that bind to mRNA targets and disturb their stability and/or translation, thus acting in gene posttranscriptional regulation. It is predicted that over 30% of mRNAs are regulated by miRNAs. Therefore these molecules are considered essential in the processing of many biological responses, such as cell proliferation, apoptosis, and stress responsiveness. As miRNAs participate of virtually all cellular pathways, their deregulation is critical to cancer development. Consequently, loss or gain of miRNAs function may contribute to tumor progression. Little is known about the regulation of miRNAs and understanding the events that lead to changes in their expression may provide new perspectives for cancer treatment. Among distinct types of cancer, melanoma has special implications. It is characterized as a complex disease, originated from a malignant transformation of melanocytes. Despite being rare, its metastatic form is usually incurable, which makes melanoma the major death cause of all skin cancers. Some molecular pathways are frequently disrupted in melanoma, and miRNAs probably have a decisive role on these alterations. Therefore, this review aims to discuss new findings about miRNAs in melanoma fields, underlying epigenetic processes, and also to argue possibilities of using miRNAs in melanoma diagnosis and therapy.
Overcoming Antiangiogenic Resistance
Authors: Yao James C. , Phan Alexandria
Published: August 2011

The success of drugs targeting angiogenesis is tempered by the transient duration of disease control and modest survival improvement. The very hypoxic stress produced by successful therapy may lead to upregulation of multiple pathways that promote angiogenesis and invasive behavior. Overcoming this evasive resistance may further improve outcome. Clin Cancer Res; 17(16); 5217–9. ©2011 AACR.
Curcumin Treatment Suppresses IKKβ Kinase Activity of Salivary Cells of Patients with Head and Neck Cancer: A Pilot Study
Authors: Kim Suejung G. , Veena Mysore S. , Basak Saroj K. , Han Eugene , Tajima Tracey , Gjertson David W. , Starr Joshua , Eidelman Ofer , Pollard Harvey B. , Srivastava Meera , Srivatsan Eri S. , Wang Marilene B.
Published: August 2011

Purpose: To determine whether curcumin would inhibit IκB kinase β (IKKβ) kinase activity and suppress expression of proinflammatory cytokines in head and neck squamous cell carcinoma cancer (HNSCC) patients.

Experimental Design: Saliva was collected before and after subjects chewed curcumin tablets. Protein was extracted and IKKβ kinase activity measured. Interleukin (IL)-6 and IL-8 levels in the salivary supernatants were measured by ELISA. IL-6, IL-8, and other interleukin were also measured independently with ELISA to confirm the inhibitory effect of curcumin on expression and secretion of salivary cytokines.

Results: Curcumin treatment led to a reduction in IKKβ kinase activity in the salivary cells of HNSCC patients (P < 0.05). Treatment of UM-SCC1 cells with curcumin as well as with post-curcumin salivary supernatant showed a reduction of IKKβ kinase activity. Significant reduction of IL-8 levels (P < 0.05) was seen in post-curcumin samples from patients with dental caries. Although there was reduced IL-8 expression in 8 of 21 post-curcumin samples of HNSCC patients, the data did not reach statistical significance. Saliva samples from HNSCC patients were also analyzed in a blinded fashion for expression of cytokines. IL-10, IFN-γ, IL-12p70, and IL-2 clustered together, and granulocyte macrophage colony stimulating factor and TNF-α clustered together. Log10 ratio analysis showed decrease in expression of all nine cytokines in both the salivary supernatant and salivary cells of curcumin-treated samples.

Conclusions: Curcumin inhibited IKKβ kinase activity in the saliva of HNSCC patients, and this inhibition correlated with reduced expression of a number of cytokines. IKKβ kinase could be a useful biomarker for detecting the effect of curcumin in head and neck cancer. Clin Cancer Res; 17(18); 5953–61. ©2011 AACR.
Prevalence and associated risk factors for postpartum depression in women attending a tertiary hospital, Delhi, India
Authors: Dubey Chandan , Gupta Neha , Bhasin Sangeeta , Muthal Rathore Asmita , Arora Raksha
Published: August 2011

Background:

Maternal mental health is a largely ignored issue in the Indian population. Considering the high prevalence of postpartum depression, mental health assessment and screening of high-risk cases should be a part of routine antenatal care.

Aim:

To study the prevalence of women at risk for peripartum depression using Edinburgh Postnatal Depression Scale (EPDS) score in a tertiary teaching hospital in New Delhi, and to study the associated risk factors in the Indian population.

Method:

Five hundred and six (506) peripartum women were interviewed using a structured questionnaire, which included sociodemographic details like socioeconomic status, family structure, relationship with husband and mother-in-law, past obstetric history and gender of children, any history of previous psychiatric illness and outcome of current pregnancy in terms of mode of delivery, gender of newborn and neonatal complications. EPDS scoring was done using a Hindi translated version. Data were analysed using Epi Info version 3.32.

Results:

Thirty one (6%) out of 506 women scored ≥ 10 on the EPDS. Birth of female child, nuclear family structure and poor marital relationship were found to have a statistically significant correlation with peripartum depression.

Conclusion:

The 6% prevalence of women at risk of peripartum depression in our study, which is similar to other such studies, is significant and hence maternal mental health assessment should be made a part of routine antenatal and postnatal care.
Pilot Test Results of an HIV Prevention Intervention for High-Risk Women
Authors: Mallory Caroline , Hesson-McInnis Matthew
Published: August 2011

Minority women, incarcerated women, and women using drugs or engaged in survival sex are most vulnerable to HIV. This pilot study was designed to estimate efficacy of an intervention, Women First!, to help these women correctly and consistently use male condoms. Women ( N = 74) were recruited from jails, substance-abuse treatment centers, and public health clinics, and enrolled in a randomized controlled trial with an attention-only comparison group. The intervention, based on social cognitive theory and the theory of gender and power and awakening, was delivered over 6 weeks; unprotected vaginal intercourse and correct condom use were measured before and after the intervention. Changes on the dependent variables did not rise to statistical significance due to low power, but descriptive statistics and the multivariate partial η2 effect size estimate of 0.27 suggest that Women First! is a promising intervention. Future research will require improvements in recruitment, retention, and measurement.
Postcolonial Theory and the Critique of International Relations
Authors: Seth Sanjay
Published: August 2011

This article in three parts offers the beginnings of a postcolonial critique of mainstream International Relations (IR). The first part argues that IR, where it has been interested in history at all, has misdescribed the origins and character of the contemporary international order, and that an accurate understanding of the ‘expansion of the international system’ requires attention to its colonial origins. The second part suggests that IR is deeply Eurocentric, not only in its historical account of the emergence of the modern international order, but also in its account(s) of the nature and functioning of this order. The human sciences are heirs to a tradition of knowledge which defines knowledge as a relation between a cognising, representing subject and an object, such that knowledge is always ‘of’ something out there, which exists independently of its apprehension. The third part of the article suggests that knowledges serve to constitute that which they purport to merely cognise or represent, and that IR theory serves to naturalise that which is historically produced.
What’s at Stake in the Neo-Trotskyist Debate? Towards a Non-Eurocentric Historical Sociology of Uneven and Combined Development
Authors: Hobson John M.
Published: August 2011

This article seeks to appraise the direction that historical sociology has undertaken within Millennium in the last four decades while simultaneously laying out the groundwork for a ‘thirdwave’ historical sociology of international relations. In particular, I intervene in the current neo-Trotskyist debate concerning whether the concept of uneven and combined development (U&CD) should be historically generalised or merely confined to the modern capitalist-industrial era that emerged as late as the 19th century. My aim is to support the former position. I argue that failure to historically generalise the concept — at least to a certain extent — leads ultimately into a Eurocentric cul-de-sac. To advance my third-wave non-Eurocentric historical sociological approach, I apply U&CD to the rise of the West in general and to British industrialisation in particular. By extending U&CD back to at least 800 CE, I argue that the West was a late developer that enjoyed the advantages of backwardness. That is, only by borrowing from, and assimilating the technologies, ideas and institutions of, the key early developers — China, India and the Islamic Middle East/North Africa — could Europe rise up from its tiny promontory on the far western edge of the vast Afro-Asian economy to eventually overtake its Eastern predecessors some time during the 19th century.
Students’ Perceptions of Accommodations in High School and College
Authors: Bolt Sara E. , Decker Dawn M. , Lloyd Megan , Morlock Larissa
Published: August 2011

A total of 55 college students with reading- and writing-related disabilities were asked to report on their high school and college experiences with 14 accommodations. Receiving assistance with having materials read aloud, extended time, and individual setting were the accommodations reported as being used by most students. Students tended to report that accommodations were helpful. Some students reported using particular accommodations more frequently than others. More than one third of the students who participated reported not receiving special education or 504 plan services during high school, and thus numbers of students reporting use of accommodations in college tended to be higher than for high school, although use did vary by specific accommodation. A variety of perceived barriers and facilitators to their use of accommodations was reported, including system-level variables, instructor knowledge and attitudes, and students’ own self-advocacy efforts. Implications for practice and research are discussed.
Gender Sensitivity Among Social Workers Handling Cases of Domestic Violence
Authors: Leung Lai Ching
Published: August 2011

This article examines gender sensitivity among social workers in different service settings, who handle domestic violence cases and its implications for social workers' professional development in Hong Kong. The findings of in-depth interviews with both social workers and survivors of domestic violence revealed that the major difference in the handling of domestic violence cases by social workers in family settings and those working in shelters or with survivors' groups is that the former perceive women’s problems as family problems that require mediation and adjustment, whereas the latter consider them to arise from an imbalance in power relations between men and women, thus leading them to focus on enhancing women’s well-being in their practice. Helping social workers to recognize structural inequality between men and women is the starting point for the development of gender-sensitive practice in domestic violence cases.