bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibrio cholerae Requires the Type VI Secretion System Virulence Factor VasX To Kill Dictyostelium discoideum
Authors: Miyata Sarah T. , Kitaoka Maya , Brooks Teresa M. , McAuley Steven B. , Pukatzki Stefan
Published: May 2011

The type VI secretion system (T6SS) is recognized as an important virulence mechanism in several Gram-negative pathogens. In
Vibrio cholerae
, the causative agent of the diarrheal disease cholera, a minimum of three gene clusters—one main cluster and two auxiliary clusters—are required to form a functional T6SS apparatus capable of conferring virulence toward eukaryotic and prokaryotic hosts. Despite an increasing understanding of the components that make up the T6SS apparatus, little is known about the regulation of these genes and the gene products delivered by this nanomachine. VasH is an important regulator of the
V. cholerae
T6SS. Here, we present evidence that VasH regulates the production of a newly identified protein, VasX, which in turn requires a functional T6SS for secretion. Deletion of
vasX
does not affect export or enzymatic function of the structural T6SS proteins Hcp and VgrG-1, suggesting that VasX is dispensable for the assembly of the physical translocon complex. VasX localizes to the bacterial membrane and interacts with membrane lipids. We present VasX as a novel virulence factor of the T6SS, as a
V. cholerae
mutant lacking
vasX
exhibits a phenotype of attenuated virulence toward
Dictyostelium discoideum.
Anaerobiosis-Induced Loss of Cytotoxicity Is Due to Inactivation of Quorum Sensing in Pseudomonas aeruginosa
Authors: Lee Kang-Mu , Yoon Mi Young , Park Yongjin , Lee Joon-Hee , Yoon Sang Sun
Published: May 2011

Pseudomonas aeruginosa
, an opportunistic pathogen of clinical importance, causes chronic airway infections in patients with cystic fibrosis (CF). Current literature suggests that pockets with reduced oxygen tension exist in the CF airway mucus. However, virulence features of this opportunistic pathogen under such conditions are largely unknown. Cell-free supernatant of the standard laboratory
P. aeruginosa
strain PAO1 obtained from anaerobic culture, but not aerobic culture, failed to kill A549 human airway epithelial cells. Further investigation revealed that this reduced cytotoxicity upon anaerobiosis was due to the suppressed secretion of elastase, a virulence factor controlled by
P. aeruginosa
quorum sensing (QS). Both a
lacZ
-reporter fusion assay and quantitative real-time PCR (RT-PCR) analysis demonstrated that transcription of the elastase-encoding
lasB
gene was substantially decreased during anaerobic growth compared with aerobic growth. Moreover, transcription of other genes controlled by the LasI/R QS system, such as
rhlR
,
vqsR
,
mvfR
, and
rsaL
, was also repressed under the same anaerobic growth conditions. Importantly, synthesis of 3-oxo-C
12
-HSL (PAI-1), an autoinducer molecule that mediates induction of the LasI/R QS system, was >22-fold decreased during anaerobic growth while C
4
-HSL (PAI-2), which mediates RhlI/R QS, was nondetectable under the same growth conditions. Transcription of the
lasB
gene was restored by exogenous supplementation with autoinducers, with PAI-2 more effective than PAI-1 or
Pseudomonas
quinolone signal (PQS) at restoring transcription of the
lasB
gene. Together, these results suggest that anaerobiosis deprives
P. aeruginosa
of the ability to regulate its virulence via QS and this misregulation attenuates the pathogenic potential of this important pathogen.
Genetic diversity and population structure of Clavibacter michiganensis subsp. nebraskensis
Authors: Agarkova I.V. , Lambrecht P.A. , Vidaver A.K.
Published: May 2011

Clavibacter michiganensis subsp. nebraskensis (CMN) is a gram-positive bacterium and an incitant of Goss’s bacterial wilt and leaf blight or “leaf freckles” in corn. A population structure of a wide temporal and geographic collection of CMN strains (n = 131), originating between 1969 and 2009, was determined using amplified fragment length polymorphism (AFLP) analysis and repetitive DNA sequence-based BOX-PCR. Analysis of the composite data set of AFLP and BOX-PCR fingerprints revealed two groups with a 60% cutoff similarity: a major group A (n = 118 strains) and a minor group B (n = 13 strains). The clustering in both groups was not correlated with strain pathogenicity. Group A contained two clusters, A1 (n = 78) and A2 (n = 40), with a linkage of 75%. Group A strains did not show any correlation with historical, geographical, morphological, or physiological properties of the strains. Group B was very heterogeneous and eight out of nine clusters were represented by a single strain. The mean similarity between clusters in group B varied from 13% to 63%. All strains in group B were isolated after 1999. The percentage of group B strains among all strains isolated after 1999 (n = 69) was 18.8%. Implications of the findings are discussed.
Construction and characterization of Lactobacillus pentosus expressing the D antigenic site of the spike protein of Transmissible gastroenteritis virus
Authors: Di-qiu Liu , Xin-yuan Qiao , Jun-wei Ge , Li-jie Tang , Yan-ping Jiang , Yi-jing Li
Published: May 2011

This study explored the feasibility of Lactobacillus pentosus as a live vehicle to deliver and express antigen. First of all, L. pentosus transformed by electroporation with the plasmids pg611-6D (anchored) and pg612-6D (secretory) based on the xylose operon generated the recombinant strains rLppg611-6D and rLppg612-6D, respectively, expressing the D antigenic site of the spike (S) protein of Transmissible gastroenteritis virus (TGEV), for intragastric administration in mice. Secondly, we collected serum, fecal, nasal, ophthalmic, and vaginal samples from pre-immune mice and after the first immunization (on days 7, 14, 21, 28, 35, and 42) that were used to analyze the levels of immunoglobulins G and A against TGEV by using ELISA. In addition, a plaque reduction assay was performed using sera from groups pg611, pg612-6D, pg11-6D, and phosphate-buffered saline (blank control) to analyze TGEV-neutralizing antibody activity in vitro. A statistically significant difference in serum tests between groups demonstrated that rLppg612-6D induced better immunogenicity than rLppg611-6D, making rLppg612-6D the better candidate for oral vaccine. Taken together, L. pentosus possessed the potential to become a novel vector for mucosal vaccine in the future.
EXISTENCE AND EQUILIBRATION OF GLOBAL WEAK SOLUTIONS TO KINETIC MODELS FOR DILUTE POLYMERS I: FINITELY EXTENSIBLE NONLINEAR BEAD-SPRING CHAINS
Authors: BARRETT JOHN W. , SÜLI ENDRE
Published: May 2011

We show the existence of global-in-time weak solutions to a general class of coupled FENE-type bead-spring chain models that arise from the kinetic theory of dilute solutions of polymeric liquids with noninteracting polymer chains. The class of models involves the unsteady incompressible Navier–Stokes equations in a bounded domain in ℝd, d = 2 or 3, for the velocity and the pressure of the fluid, with an elastic extra-stress tensor appearing on the right-hand side in the momentum equation. The extra-stress tensor stems from the random movement of the polymer chains and is defined by the Kramers expression through the associated probability density function that satisfies a Fokker–Planck-type parabolic equation, a crucial feature of which is the presence of a centre-of-mass diffusion term. We require no structural assumptions on the drag term in the Fokker–Planck equation; in particular, the drag term needs not be corotational. With a square-integrable and divergence-free initial velocity datum ṵ0 for the Navier–Stokes equation and a non-negative initial probability density function ψ0 for the Fokker–Planck equation, which has finite relative entropy with respect to the Maxwellian M, we prove, via a limiting procedure on certain regularisation parameters, the existence of a global-in-time weak solution t ↦ (ṵ(t), ψ(t)) to the coupled Navier–Stokes–Fokker–Planck system, satisfying the initial condition (ṵ(0), ψ(0)) = (ṵ0, ψ0), such that t ↦ ṵ(t) belongs to the classical Leray space and t ↦ ψ(t) has bounded relative entropy with respect to M and t ↦ ψ(t)/M has integrable Fisher information (w.r.t. the measure [Formula: see text] over any time interval [0, T], T > 0. If the density of body forces [Formula: see text] on the right-hand side of the Navier–Stokes momentum equation vanishes, then a weak solution constructed as above is such that t ↦ (ṵ(t), ψ(t)) decays exponentially in time to [Formula: see text] in the [Formula: see text] norm, at a rate that is independent of (ṵ0, ψ0) and of the centre-of-mass diffusion coefficient.
COMPUTABLE STRUCTURES OF RANK $\omega_{1}^{{\rm CK}}$
Authors: KNIGHT J. F. , MILLAR J.
Published: May 2011

For countable structure, "Scott rank" provides a measure of internal, model-theoretic complexity. For a computable structure, the Scott rank is at most [Formula: see text]. There are familiar examples of computable structures of various computable ranks, and there is an old example of rank [Formula: see text]. In the present paper, we show that there is a computable structure of Scott rank [Formula: see text]. We give two different constructions. The first starts with an arithmetical example due to Makkai, and codes it into a computable structure. The second re-works Makkai's construction, incorporating an idea of Sacks.
THE EXTENSION OF DUTTA–RAY'S SOLUTION TO CONVEX NTU GAMES
Authors: YANOVSKAYA ELENA
Published: May 2011

The egalitarian solution for the class of convex TU games was defined by Dutta and Ray [1989] and axiomatized by Dutta 1990. An extension of this solution — the egalitarian split-off set (ESOS) — to the class of non-levelled NTU games is proposed. On the class of TU games it coincides with the egalitarian split-off set [Branzei et al. 2006]. The proposed extension is axiomatized as the maximal (w.r.t. inclusion) solution satisfying consistency à la Hart–Mas-Colell and agreeing with the solution of constrained egalitarianism for arbitrary two-person games. For ordinal convex NTU games the ESOS turns out to be single-valued and contained in the core. The totally cardinal convexity property of NTU games is defined. For the class of ordinal and total cardinal convex NTU games an axiomatic characterization of the Dutta–Ray solution with the help of Peleg consistency is given.
FISH WARS WITH MANY PLAYERS
Authors: MAZALOV VLADIMIR V. , RETTIEVA ANNA N.
Published: May 2011

Discrete-time game-theoretic models related to a bioresource management problem (fish catching) are investigated. There are some players (countries or fishing firms) which harvest the fish stock. Power population's growth function and logarithmic players' profits are considered.

We derive the Nash and cooperative equilibria. We construct the characteristic function for cooperative game in two unusual forms and determine the Shapley value and time-consistent imputation distribution procedure [Petrosjan (1977)].

We propose the condition which gives an incentive for the players to keep cooperation at each stage and compare it with the "irrational-behavior-profness" condition [Yeung (2006)].

We propose the linear programming method to find the time-consistent "rational" solution in C-core. The numerical modelling and the results' comparison were carried out.
NON-COOPERATIVE AND AXIOMATIC CHARACTERIZATIONS OF THE AVERAGE LEXICOGRAPHIC VALUE
Authors: KONGO TAKUMI , FUNAKI YUKIHIKO , BRANZEI RODICA , TIJS STEF
Published: May 2011

We give a non-cooperative and an axiomatic characterization of the Average Lexicographic value (AL-value) on the class of balanced games. The AL-value is a single-valued solution for balanced TU-games. It is defined as the average of lexicographic maximum of the core of the game with respect to all orders on the player set, and it can be seen as a core selection based on the priority orders on the players. In both of our characterizations of the AL-value, a consistency property which we call average consistency plays an important role, and the property is obtained by the consistency property à la Davis and Maschler of the lexicographic vectors with respect to any order of players.
TWO-STEP "WIN-STAY, LOSE-SHIFT" AND LEARNING TO COOPERATE IN THE REPEATED PRISONER'S DILEMMA
Authors: KRYAZHIMSKIY ARKADY
Published: May 2011

The standard win-stay, lose-shift behavior strategy in the repeated Prisoner's Dilemma game prescribes the players that win and lose in a current game round to keep and to change, respectively, their current actions, in the next round. Winning and losing are understood as receiving one of two upper values and one of two lower values, respectively, among the four admissible values for the players' benefits. In particular, a player acting as a cooperator against cooperation wins and therefore is not allowed to switch to defection in the next round with a hope to gain more (provided his/her rival keeps cooperating). This constraint can be viewed as too strong for a selfish player. Here, we discuss a two-step win-stay, lose-shift behavior that differs from the traditional win-stay lose-shift one in understanding of winning and losing. A player wins if his/her benefit is no smaller that in the previous round, and loses otherwise. This pattern is in a sense more selfish; in particular, a switch from cooperation (against cooperation) to defection is not forbidden. Another confirmation of a more selfish character of the two-step win-stay, lose-shift behavior, compared to the standard win-stay, lose-shift one, is that the former does not bring two individuals playing the repeated Prisoner's Dilemma game to mutual cooperation. In this paper, our goal is to understand to what degree one can relax the two-step win-stay, lose-shift behavior in selfishness so as to reach mutual cooperation, anyway. We deal with two models of the repeated Prisoner's Dilemma game — a game of two individuals and a game in a group of players. In the game of two individuals, a relaxed two-step win-stay, lose-shift behavior assumes that the players use mixed strategies; here, relaxation is associated with patience. In the game in a group of players, relaxation is achieved through conformity, a tendency to join the majority. We show that even a small degree of conformity is enough to teach a two-step win-stay, lose-shift group to cooperate.
STABLE COOPERATION UNDER ENVIRONMENTAL CONSTRAINTS
Authors: KOZLOVSKAYA NADEZHDA , ZENKEVICH NIKOLAY
Published: May 2011

A game-theoretic model of territorial environmental production under Cournot competition is studied. The process is modeled as cooperative differential game. The stable distribution mechanism of the common cooperative benefit among players is proposed. We proved that the cooperative total stock of accumulated pollution is strictly less then the pollution under Nash equilibrium for the whole duration of the game. We design a stable Shapley value as a cooperative solution, which is time-consistent. The Shapley value is also strategic stable and satisfies the irrational-behavior-proofness condition. The numerical example is given.
DYNAMIC GAME OF OFFENDING AND LAW ENFORCEMENT: A STOCHASTIC EXTENSION
Authors: YEUNG DAVID W. K. , ZHANG YINGXUAN , YEUNG PATRICIA M. , MAK DEMI
Published: May 2011

This article provides an extension of the Fend-Feichtinger-Tragler dynamic game of offending and law enforcement to a stochastic framework. This allows the analysis to reflect actual crime statistics which displays randomness in its distribution. Stochastic paths of crimes are derived. The asymptotic stationary distribution of crime records is also obtained.
PHASE NOISE SUPPRESSION IN GPS-DISCIPLINED FREQUENCY SYNCHRONIZATION SYSTEMS
Authors: WANG WEN-QIN
Published: May 2011

Global positioning system (GPS)-disciplined quartz oscillator can provide a precise time and frequency standard. However, possible phase errors and biases caused by oscillator phase noise must be suppressed or compensated for some applications, e.g., distributed radar systems, in which a rigorous phase or frequency synchronization precision is required. Moreover, the quartz oscillator is necessary to provide a holdover of time or frequency when the GPS signals are lost. This letter presents a signal processing and hardware design strategy for suppressing phase noise in GPS-disciplined frequency synchronization systems. Firstly, the quartz oscillator frequency is disciplined by the GPS pulse-per-second (PPS) signals. Next, a recursive algorithm is applied to suppress the possible jitters when the GPS PPS signals are lost. Finally, a direct digital synthesizer (DDS)-based multiple frequency tuning synthesizer is presented to generate the whole system frequencies. Although the use of GPS signal to discipline oscillator for frequency transfer is not a new concept, the originality of this letter lies in the proposed phase noise suppression methods, along with the hardware design strategies.
Sex-Specific Gait Patterns of Older Adults with Knee Osteoarthritis: Results from the Baltimore Longitudinal Study of Aging
Authors: Ko Seung-uk , Simonsick Eleanor M. , Husson Liz M. , Ferrucci Luigi
Published: May 2011

Men and women exhibit different gait patterns during customary walking and may respond differently to joint diseases. The present paper aims to identify gait patterns associated with knee-OA separately in men and women. Participants included 144 men and 124 women aged 60 years and older enrolled in the Baltimore Longitudinal Study of Aging (BLSA) who underwent gait testing at a self-selected speed. Both men and women with knee-OA had lower ankle propulsion mechanical work expenditure (MWE;P<.001for both) and higher hip generative MWE (P<.001) compared to non-OA controls. Women with knee-OA had a higher BMI (P=.008), slower gait speed (P=.049), and higher knee frontal-plane absorbing MWE (P=.007) than women without knee-OA. These differences were not observed in men. Understanding sex-specific differences in gait adaptation to knee-OA may inform the development of appropriate strategies for early detection and intervention for knee-OA in men and women.
A Numerical Method for Preserving Curve Edges in Nonlinear Anisotropic Smoothing
Authors: Hu Shaoxiang , Liao Zhiwu , Sun Dan , Chen Wufan
Published: May 2011

We focus on nonlinearity for images and propose a new method which can preserve curve edges in image smoothing using nonlinear anisotropic diffusion
(NAD). Unlike existing methods which diffuse only among the spatial variants, the new method suggests that the diffusion should be performed both among the time variants and spatial variants, named time and space nonlinear anisotropic diffusion (TSNAD). That is, not only the differences of the spatial variants should be estimated by the nearby spatial points but also the differences of the time variants should be approximated by the weighted time differences of nearby points, according to the differences of gray levels between them and the consideration point. Since the time differences of nearby points using NAD can find more points with similar gray levels which form a curve belt for the center pixel on a curve edge, TSNAD can provide satisfied smoothing results while preserving curve edges. The experiments for digital images also show us the ability of TSNAD to preserve curve edges.
A Simple Introduction to Gröbner Basis Methods in String Phenomenology
Authors: Gray James
Published: May 2011

I give an elementary introduction to the key algorithm used in recent applications of computational algebraic geometry to the subject of string phenomenology. I begin with a simple description of the algorithm itself and then give 3 examples of its use in physics. I describe how it can be used to obtain constraints on flux parameters, how it can simplify the equations describing vacua in 4D string models, and lastly how it can be used to compute the vacuum space of the electroweak sector of the MSSM.
Type I Diabetes-Associated Tolerogenic Properties of Interleukin-2
Authors: Chentoufi Aziz Alami , Gaudreau Simon , Nguyen Alex , Sabha Mahmoud , Amrani Abdelaziz , ElGhazali Geyhad
Published: May 2011

Type 1 Diabetes (T1D) results from insulin-producing beta cells destruction by diabetogenic T lymphocytes in humans and nonobese diabetic (NOD) mice. The breakdown of tolerance has been associated with a defect in the number and the function of naturally occurring regulatory T cells (nTreg) that are the master player in peripheral tolerance. Gene knockout experiments in mouse models have shown a nonredundant activity of IL-2 related to its critical role in inducing nTreg and controlling peripheral T cell tolerance. Whereas strong evidence has suggested that IL-2 is critically required for nTreg-mediated T1D control, several fundamental questions remain to be addressed. In this paper, we highlight the recent findings and controversies regarding the tolerogenic properties of IL-2 mediated through nTreg. We further discuss a potential link between the immunomodulatory role of interleukin-2 and the pathogenesis of type 1 diabetes.
Unusual Paraneoplastic Syndrome Accompanies Neuroendocrine Tumours of the Pancreas
Authors: Bertani Helga , Messerotti Alessandro , Di Benedetto Fabrizio , Manta Raffaele , Greco Milena , Casoni Federica , Losi Luisa , Conigliaro Rita
Published: May 2011

Neuroendocrine tumours comprise a small percentage of pancreatic neoplasia (10%) (1). Diagnosis of neuroendocrine tumours is difficult, especially if the tumours are small and nonfunctional. CT scans, MRI, and nuclear scans are sufficiently sensitive assessment tools for tumours with diameters of at least 2 cm; otherwise, the sensitivity and specificity of these techniques is less than 50% (2). Myasthenia gravis (MG) is a heterogeneous neuromuscular junction disorder that is primarily caused when antibodies form against the acetylcholine receptors (Ab-AchR). MG can develop in conjunction with neoplasia, making MG a paraneoplastic disease. In those cases, MG is most commonly associated with thymomas and less frequently associated with extrathymic malignancies. The mechanism underlying this paraneoplastic syndrome has been hypothesized to involve an autoimmune response against the tumour cells (3). No published reports have linked malignant pancreatic diseases with MG. Here, we report the case of a young woman, negative for Ab-AchR, with a neuroendocrine tumour in the pancreatic head, who experienced a complete resolution of her MG-like syndrome after surgical enucleation of the tumour.
Existence and Uniqueness of the Solution for aTime‐Fractional Diffusion Equation with Robin Boundary Condition
Authors: Kemppainen Jukka
Published: May 2011

Existence and uniqueness of the solution for a time‐fractional
diffusion equation with Robin boundary condition on a bounded domain with
Lyapunov boundary is proved in the space of continuous functions up to boundary.
Since a Green matrix of the problem is known, we may seek the solution
as the linear combination of the single‐layer potential, the volume potential, and
the Poisson integral. Then the original problem may be reduced to a Volterra
integral equation of the second kind associated with a compact operator. Classical analysis may be employed to show that the corresponding integral equation
has a unique solution if the boundary data is continuous, the initial data
is continuously differentiable, and the source term is Hölder continuous in the
spatial variable. This in turn proves that the original problem has a unique
solution.
Tungsten/Platinum Hybrid Nanowire Growth via Field Emission Using Nanorobotic Manipulation
Authors: Yang Zhan , Nakajima Masahiro , Ode Yasuhito , Fukuda Toshio
Published: May 2011

This paper reports tungsten-platinum hybrid nanowire growth via field emission, based on nanorobotic manipulation within a field emission scanning electron microscope (FESEM). A multiwalled carbon nanotube (MWCNT) was used as the emitter, and a tungsten probe was used as the anode at the counterposition, by way of nanomanipulation. By independently employing trimethylcyclopentadienyl platinum (CpPtMe3) and tungsten hexacarbonyl (W(CO)6) as precursors, the platinum nanowire grew on the tip of the MWCNT emitter. Tungsten nanowires then grew on the tip of the platinum nanowire. The hybrid nanowire length wascontrolled by nanomanipulation. Their purity was evaluated using energy-dispersive X-ray spectroscopy (EDS). Thus, it is possible to fabricate various metallic hybrid nanowires by changing the precursor materials. Hybrid nanowires have various applications in nanoelectronics, nanosensor devices, and nanomechanical systems.
Virological Breakthrough: A Risk Factor for Loss to Followup in a Large Community-Based Cohort on Antiretroviral Therapy
Authors: Orrell Catherine , Kaplan Richard , Wood Robin , Bekker Linda-Gail
Published: May 2011

Background. We have previously shown that 75% of individuals on antiretroviral therapy (ART) in a resource-limited setting who experienced virological breakthrough to >1000 copies/mL were resuppressed after an intensive adherence intervention. This study examines the long-term outcomes of this group in order to understand the impact of the adherence intervention over time.Methods. ART-naïve adults commencing ART between September 2002 and December 2009 were reviewed. Those who achieved suppression (<50 copies/mL) were categorised by subsequent viral load: any >1000 copies/mL (virological breakthrough) or not. Those with breakthrough were sub-categorised by following viral load into failed (VL > 1000 copies/mL) or resuppressed (VL < 1000 copies/mL). Their outcome (lost-to follow-up, death, in care on first-line therapy or in care on second-line therapy) was determined as of the 13th April 2010.Findings. 4047 ART-naïve adults commenced ART. 3086 had >2 viral loads and were included in the analysis. 2959 achieved virological suppression (96%). Thereafter 2109 (71%) remained suppressed and 850 (29%) experienced breakthrough ( (33%) failed and (67%) resuppressed). Individuals with breakthrough were younger (), had lower CD4 counts (), and higher viral loads () than those who remained suppressed. By 7 years the risk of breakthrough was 42% and of failure 15%. Fewer adults with breakthrough remain in care over time (). Loss to care is similar whether the individuals failed or resuppressed.Interpretation. While 67% of those who experience initial virological breakthrough resuppress after an adherence intervention, these individuals are significantly less likely be retained in care than those who remain virologically suppressed throughout.
Two New Types of Rings Constructed from Quasiprime Ideals
Authors: Ghanem Manal , Al-Ezeh Hassan
Published: May 2011

Keigher showed that quasi‐prime ideals in differential commutative rings are analogues of prime ideals in commutative rings. In that direction, he introduced and studied new types of differential rings using quasi‐prime ideals of a differential ring. In the same sprit, we define and study two new types of differential rings which lead to the mirrors of the corresponding
results on von Neumann regular rings and principally flat rings (PF‐rings) in commutative rings, especially, for rings of positive characteristic.
Successful Treatment of Stent Knot in the Proximal Ureter Using Ureteroscopy and Holmium Laser
Authors: Richards Masters M. , Khalil Daniel , Mahdy Ayman
Published: May 2011

Knotted ureteral stent is rare yet tedious complication that might represent a treatment challenge to the endourologist. Only twelve cases of knotted stent have been reported. Different management options have been reported, including simple traction, ureteroscopy, percutaneous removal, and open surgery. In this paper, we present the successful untying of the knot using ureteroscopy with holmium laser.
Strong Convergence Theorems of Modified Ishikawa Iterative Method for an Infinite Family of Strict Pseudocontractions in Banach Spaces
Authors: Katchang Phayap , Kumam Wiyada , Humphries Usa , Kumam Poom
Published: May 2011

We introduce a new modified Ishikawa iterative process and a new W‐mapping for comput‐
ing fixed points of an infinite family of strict pseudocontractions mapping in the framework of q‐uniformly
smooth Banach spaces. Then, we establish the strong convergence theorem of the proposed iterative scheme
under some mild conditions. The results obtained in this paper extend and improve the recent results of
Cai and Hu 2010, Dong et al. 2010, Katchang and Kumam 2011 and many others in the literature.
Pros and Cons of Focal Therapy for Localised Prostate Cancer
Authors: Mearini Luigi , Porena Massimo
Published: May 2011

In prostate cancer, an interesting and intriguing option to overcome the risks of whole-gland treatment is focal therapy, with the aim of eradicating known cancer foci and reducing collateral damages to the structures essential for maintaining normal urinary and sexual function. Ablation of all known lesions would favorably alter the natural history of the cancer without impacting health-related quality of life and allows for safe retreatment with repeated focal therapy or whole-gland approaches if necessary. Our objective is to reassess the possibilities and criticisms of such procedure: the rationale for focal therapy and the enthusiasm come from the success of conservative approaches in treating other malignancies and in the high incidence of overtreatment introduced by prostate cancer screening programs. One of the challenges in applying such an approach to the treatment of prostate cancer is the multifocal nature of the disease and current difficulties in accurate tumor mapmaking.
Surface Modification of Gelatin Nanoparticles with Polyethylenimine as Gene Vector
Authors: Kuo Wei-Ti , Huang Hong-Yi , Chou Min-Ju , Wu Meng-Chao , Huang Yi-You
Published: May 2011

A novel carrier on balancing the transfection efficiency and minimizing cytotoxicity was designed. Gelatin cross-linked with 1.8 kDa of PEI (GA-PEI 1.8 k) formed stable complex and resulted in high positiveζpotential (42.47 mV) and buffering effect. These nanoparticles with N/P ratio of 30 give high transfection efficiency  RLU/μg protein and cell viability (86.4%). These modified GA-PEI nanoparticles, with high transfection efficiency and low cell toxicity, can be a potential gene vector in gene therapy.
Granulocytic Sarcoma in a Nonleukemic Patient: Place of Radiotherapy and Systemic Therapies
Authors: Chargari C. , Jacob J. , Bauduceau O. , Ferrand F. R. , De Revel T. , Védrine L.
Published: May 2011

Granulocytic sarcoma is a rare extramedullary tumour, which most often occurs in the course of an acute or chronic leukaemia or myeloproliferative disorders. Rarely it is found before peripheral blood or bone marrow evidence of leukemia is present. We report an unusual case of acute paraplegia at first presentation of a spinal epidural granulocytic sarcoma without any haematological disorder. Therapeutic strategies are discussed in the light of the literature.
Tissue Expansion: Further Attempts to Improve Results in Breast Reconstruction
Authors: Hudson Donald A. , Adams Kevin G. , Adams Saleigh
Published: May 2011

Tissue expansion, is a simple method of breast reconstruction. Method. A prospective study of 27 patients treated over a 43 month period is described. At the first stage the expander is inserted in the dual plane, and the medial pectoral nerve is divided. The tissue expander is over-expanded. Second stage: a de-epithelialized vertical triangle is used to aid anterior projection, an inframammary fold is created and a silicone gel prosthesis inserted. Z-plasties are added to the transverse scar. The contralateral breast can be treated or left alone. Complications were recorded and the results were assessed by 4 plastic surgeons using a visual analogue scale.
Results. 19 patients had expanders inserted at mastectomy (2 bilateral) and 8 underwent delayed reconstruction, with a mean age of 47 years (range 30–65 years). A single prosthesis was inserted in 15 patients (mean size 320 mL) and two prosthesis were stacked in 12 patients (mean volume of 400 mL). The mean delay from full expansion to the second stage was 10 weeks (range 3 weeks–11 months).
A contralateral augmentation was performed in 5 patients, pexy in 10, a reduction in 2 and in 8 patients no procedure was performed.
One patient required explantation. The mean visual analogue assessment was 7.
Conclusion. This technique should be considered enhance the cosmetic results in tissue expansion.
Nuclear ErbB2 Enhances Translation and Cell Growth by Activating Transcription of Ribosomal RNA Genes
Authors: Li Long-Yuan , Chen Hsiuyi , Hsieh Yi-Hsien , Wang Ying-Nai , Chu Hsiao-Ju , Chen Ya-Huey , Chen Hui-Yu , Chien Peng-Ju , Ma Haou-Tzong , Tsai Ho-Cheng , Lai Chien-Chen , Sher Yuh-Pyng , Lien Huang-Chun , Tsai Chang-Hai , Hung Mien-Chie
Published: May 2011

Aberrant regulation of rRNA synthesis and translation control can facilitate tumorigenesis. The ErbB2 growth factor receptor is overexpressed in many human tumors and has been detected in the nucleus, but the role of nuclear ErbB2 is obscure. In this study, we defined a novel function of nuclear ErbB2 in enhancing rRNA gene transcription by RNA polymerase-I (RNA Pol I). Nuclear ErbB2 physically associates with β-actin and RNA Pol I, coinciding with active RNA Pol I transcription sites in nucleoli. RNA interference–mediated knockdown of ErbB2 reduced pre-rRNA and protein synthesis. In contrast, wild-type ErbB2 augmented pre-rRNA level, protein production, and cell size/cell growth, but not by an ErbB2 mutant that is defective in nuclear translocation. Chromatin immunoprecipitation assays revealed that ErbB2 enhances binding of RNA Pol I to rDNA. In addition, ErbB2 associated with rDNA, RNA Pol I, and β-actin, suggesting how it could stimulate rRNA production, protein synthesis, and increased cell size and cell growth. Finally, ErbB2-potentiated RNA Pol I transcription could be stimulated by ligand and was not substantially repressed by inhibition of PI3-K and MEK/ERK (extracellular signal regulated kinase), the main ErbB2 effector signaling pathways. Together, our findings indicate that nuclear ErbB2 functions as a regulator of rRNA synthesis and cellular translation, which may contribute to tumor development and progression. Cancer Res; 71(12); 4269–79. ©2011 AACR.
Blocking EphB1 Receptor Forward Signaling in Spinal Cord Relieves Bone Cancer Pain and Rescues Analgesic Effect of Morphine Treatment in Rodents
Authors: Liu Su , Liu Wen-Tao , Liu Yue-Peng , Dong Hai-Long , Henkemeyer Mark , Xiong Li-Ze , Song Xue-Jun
Published: May 2011

Treating bone cancer pain continues to be a clinical challenge and underlying mechanisms of bone cancer pain remain elusive. Here, we report that EphB1 receptor forward signaling in the spinal cord is critical to the development of bone cancer pain and morphine tolerance in treating bone cancer pain. Tibia bone cavity tumor cell implantation (TCI) produces bone cancer–related thermal hyperalgesia, mechanical allodynia, spontaneous and movement-evoked pain behaviors, and bone destruction. Production and persistence of these pain behaviors are well correlated with TCI-induced upregulation of EphB1 receptor and its ligand ephrinB2 in the dorsal horn and primary sensory neurons. Spinal administration of an EphB1 receptor blocking reagent EphB2-Fc prevents and reverses bone cancer pain behaviors and the associated induction of c-Fos and activation of astrocytes and microglial cells, NR1 and NR2B receptors, Src within the N-methyl-D-aspartate receptor complex, and the subsequent Ca2+-dependent signals. The exogenous ligand ephrinB2-Fc upregulates level of phosphorylation of NR1 and NR2B receptors depending on the activation of EphB1 receptor. Spinal administration of EphB2-Fc and ephrinB2-Fc induces downregulation of EphB1 and ephrinB2, respectively, accompanied with increased activity of matrix metalloproteinase (MMP)-2/9. Blocking MMP-2 or MMP-9 reverses EphB1-Fc treatment–induced downregulation of EphB1 receptor. In addition, spinal blocking or targeted mutation of EphB1 receptor reverses morphine tolerance in treating bone cancer pain in rats and defensive pain in mice. These findings show a critical mechanism underlying the pathogenesis of bone cancer pain and suggest a potential target for treating bone cancer pain and improving analgesic effect of morphine clinically. Cancer Res; 71(13); 4392–402. ©2011 AACR.
TGFβ/TNFα-Mediated Epithelial–Mesenchymal Transition Generates Breast Cancer Stem Cells with a Claudin-Low Phenotype
Authors: Asiedu Michael K. , Ingle James N. , Behrens Marshall D. , Radisky Derek C. , Knutson Keith L.
Published: May 2011

Breast cancer recurrence is believed to be caused by a subpopulation of cancer cells that possess the stem cell attribute of treatment resistance. Recently, we and others have reported the generation of breast cancer stem cells (BCSC) by epithelial–mesenchymal transition (EMT), although the physiologic process by which these cells may arise in vivo remains unclear. We show here that exposure of tumor cells to TGFβ and TNFα induces EMT and, more importantly, generates cells with a stable BCSC phenotype which is shown by increased self-renewing capacity, greatly increased tumorigenicity, and increased resistance to oxaliplatin, etoposide, and paclitaxel. Furthermore, gene expression analyses found that the TGFβ/TNFα-derived BCSCs showed downregulated expression of genes encoding claudin 3, 4, and 7 and the luminal marker, cytokeratin 18. These changes indicate a shift to the claudin-low molecular subtype, a recently identified breast cancer subtype characterized by the expression of mesenchymal and stem cell-associated markers and correlated with a poor prognosis. Taken together, the data show that cytokine exposure can be used to generate stable BCSCs ex vivo, and suggest that these cells may provide a valuable tool in the identification of stem cell-directed biomarkers and therapies in breast cancer. Cancer Res; 71(13); 4707–19. ©2011 AACR.
Targeting Hyaluronidase for Cancer Therapy: Antitumor Activity of Sulfated Hyaluronic Acid in Prostate Cancer Cells
Authors: Benitez Anaid , Yates Travis J. , Lopez Luis E. , Cerwinka Wolfgang H. , Bakkar Ashraf , Lokeshwar Vinata B.
Published: May 2011

The tumor cell–derived hyaluronidase (HAase) HYAL-1 degrades hyaluronic acid (HA) into proangiogenic fragments that support tumor progression. Although HYAL-1 is a critical determinant of tumor progression and a marker for cancer diagnosis and metastasis prediction, it has not been evaluated as a target for cancer therapy. Similarly, sulfated hyaluronic acid (sHA) has not been evaluated for biological activity, although it is an HAase inhibitor. In this study, we show that sHA is a potent inhibitor of prostate cancer. sHA blocked the proliferation, motility, and invasion of LNCaP, LNCaP-AI, DU145, and LAPC-4 prostate cancer cells, and induced caspase-8–dependent apoptosis associated with downregulation of Bcl-2 and phospho-Bad. sHA inhibited Akt signaling including androgen receptor (AR) phosphorylation, AR activity, nuclear factor κB (NFκB) activation, and VEGF expression. These effects were traced to a blockade in complex formation between phosphoinositide 3-kinase (PI3K) and HA receptors and to a transcriptional downregulation of HA receptors, CD44, and RHAMM, along with PI3K inhibition. Angiogenic HA fragments or overexpression of myristoylated Akt or HA receptors blunted these effects of sHA, implicating a feedback loop between HA receptors and PI3K/Akt signaling in the mechanism of action. In an animal model, sHA strongly inhibited LNCaP-AI prostate tumor growth without causing weight loss or apparent serum-organ toxicity. Inhibition of tumor growth was accompanied by a significant decrease in tumor angiogenesis and an increase in apoptosis index. Taken together, our findings offer mechanistic insights into the tumor-associated HA–HAase system and a preclinical proof-of-concept of the safety and efficacy of sHA to control prostate cancer growth and progression. Cancer Res; 71(12); 4085–95. ©2011 AACR.
Akt2 Regulates All Akt Isoforms and Promotes Resistance to Hypoxia through Induction of miR-21 upon Oxygen Deprivation
Authors: Polytarchou Christos , Iliopoulos Dimitrios , Hatziapostolou Maria , Kottakis Filippos , Maroulakou Ioanna , Struhl Kevin , Tsichlis Philip N.
Published: May 2011

The growth and survival of tumor cells in an unfavorable hypoxic environment depend upon their adaptability. Here, we show that both normal and tumor cells expressing the protein kinase Akt2 are more resistant to hypoxia than cells expressing Akt1 or Akt3. This is due to the differential regulation of microRNA (miR) 21, which is upregulated by hypoxia only in Akt2-expressing cells. By upregulating miR-21 upon oxygen deprivation, Akt2 downregulates PTEN and activates all three Akt isoforms. miR-21 also targets PDCD4 and Sprouty 1 (Spry1), and the combined downregulation of these proteins with PTEN is sufficient to confer resistance to hypoxia. Furthermore, the miR-21 induction by Akt2 during hypoxia depends upon the binding of NF-κB, cAMP responsive element–binding protein (CREB), and CBP/p300 to the miR-21 promoter, in addition to the regional acetylation of histone H3K9, all of which are under the control of Akt2. Analysis of the Akt2/miR-21 pathway in hypoxic MMTV-PyMT–induced mouse mammary adenocarcinomas and human ovarian carcinomas confirmed the activity of the pathway in vivo. Taken together, this study identifies a novel Akt2-dependent pathway that is activated by hypoxia and promotes tumor resistance via induction of miR-21. Cancer Res; 71(13); 4720–31. ©2011 AACR.
Pneumocyte Biomarkers KL-6 and Surfactant Protein D Reflect the Distinct Findings of High-Resolution Computed Tomography in Nonspecific Interstitial Pneumonia
Authors: Ichiyasu Hidenori , Ichikado Kazuya , Yamashita Akihisa , Iyonaga Kazuhiro , Sakamoto Osamu , Suga Moritaka , Kohrogi Hirotsugu
Published: May 2011

Background: Serum levels of pneumocyte biomarkers KL-6 and surfactant protein D (SP-D) are useful diagnostic markers for interstitial lung diseases. However, associations of serum KL-6 and SP-D with radiologic findings in nonspecific interstitial pneumonia (NSIP) remain unclear. Objectives: To determine whether serum levels of KL-6 and SP-D reflect fibrotic and/or inflammatory processes in NSIP, we investigated the correlation between high-resolution computed tomography (HRCT) findings and serum KL-6 and SP-D levels. Methods: Serum levels of KL-6 and SP-D were measured in 21 patients with biopsy-confirmed NSIP. The radiographic extent of 6 HRCT patterns and total HRCT score, defined as the scored fibrotic index, were assessed. Changes in the levels of serum markers and CT findings during follow-up were also monitored. Results: Serum levels of KL-6 in NSIP positively correlated with the total HRCT score and overall extent of interstitial disease. Serum levels of SP-D in NSIP showed a positive correlation with the area of ground-glass attenuation without traction bronchiectasis and the inflammatory CT pattern, but the levels were inversely correlated with the area of ground-glass attenuation with traction bronchiectasis and the fibrotic CT pattern. The follow-up CT and serum marker changes after treatment showed that percent change of disease extent was reflected in both markers, especially KL-6. Further, the decreased fibrotic pattern correlated with both biomarkers. Conclusions: The results indicate that serum levels of KL-6 in NSIP reflect the overall extent of interstitial lesions, which include both inflammatory and fibrotic lesions, while the levels of SP-D mainly reflect the extent of inflammatory lesions.
Quantitative Assessment of Photoreceptor Layer in Eyes with Resolved Edema after Pars Plana Vitrectomy with Internal Limiting Membrane Removal for Diabetic Macular Edema
Authors: Yanyali Ates , Bozkurt Kansu T. , Macin Aydin , Horozoglu Fatih , Nohutcu Ahmet F.
Published: May 2011

Background/Aims: To evaluate the correlation between visual acuity (VA) and photoreceptor integrity in eyes with resolved diabetic macular edema (DME) after pars plana vitrectomy (PPV). Methods: Eleven eyes with resolved macular edema following PPV with internal limiting membrane removal for DME were included in this retrospective study. The integrity of the external limiting membrane (ELM) and inner and outer segments (IS/OS) of the photoreceptor junction was evaluated by spectral domain optical coherence tomography. The main outcome measures were percentage of disrupted ELM and IS/OS lines, and correlation between VA and photoreceptor integrity. Results: The mean time after PPV was 78 ± 17 months. The mean lengths of the disrupted ELM and IS/OS lines were 223 ± 167 µm (63%) and 189 ± 175 µm (54%) in the foveola, and 900 ± 522 µm (60%) and 835 ± 582 µm (55%) in the fovea, respectively. Intact ELM and IS/OS lines were positively correlated with VA in both the fovea (p = 0.09 and p = 0.02, respectively) and foveola (p = 0.004 and p = 0.03, respectively). Linear regression analysis showed a statistically significant association of intact ELM and IS/OS lines with VA in the fovea. Disrupted ELM and IS/OS lines had a strong correlation with each other in both the fovea (r = –0.71, p = 0.013) and foveola (r = 0.81, p = 0.02). Conclusions: The integrity of the ELM and IS/OS lines was positively correlated with VA in eyes with resolved DME after PPV.
Familial Semantic Dementia with P301L Mutation in the Tau Gene
Authors: Ishizuka Takanori , Nakamura Masayuki , Ichiba Mio , Sano Akira
Published: May 2011

Background/Aims: Semantic dementia (SD) is a clinical subclassification of frontotemporal lobar degeneration. Patients with ‘pure SD’ present with semantic memory impairment preceding the frontal symptoms, and there have been no reports of familial cases. Methods: We evaluated the clinical features of, and performed neuropsychological examinations on, the proband and two affected family members. Then we performed neuroimaging and genetic analysis of MAPT and other dementia-related genes in the proband. Results: All three cases had semantic memory impairment with loss of word meanings as the primary early symptom. We diagnosed all cases as pure SD and identified a P301L mutation in the MAPT gene of the proband. Conclusion: Although the P301L mutation identified here has been previously described as pathogenic for frontotemporal dementia with parkinsonism-17 (FTDP-17), the proband and his two affected relatives showed different clinical symptoms from those of typical FTDP-17 cases who carry the P301L mutation. Pathologically, pure SD usually shows a TAR DNA-binding protein proteinopathy, but the molecular understanding of SD is not well established. Although our cases were clinically pure SD, the proband has a tau gene mutation, which would lead to tauopathy. These findings suggest that reconsideration of the molecular understanding of SD is warranted.