bluuebunny/crossref_metadata_2025 huggingface dataset:
Greening Haiti, Tree by Tree
Authors: Gibbons Ann
Published: February 2010

Haiti desperately needs trees, now more than ever. But how best to plant them in a nation whose forests are all but gone?
Antistaphylococcal Activities of Telavancin Tested Alone and in Combination by Time-Kill Assay
Authors: Lin Gengrong , Pankuch Glenn A. , Ednie Lois M. , Appelbaum Peter C.
Published: February 2010

Synergy time-kill studies against 40 methicillin-resistant
Staphylococcus aureus
(MRSA) strains of differing resistance phenotypes were conducted. Subinhibitory concentrations of telavancin were combined with sub-MIC concentrations of other antimicrobial agents that might be used in combination with telavancin to provide Gram-negative coverage. The highest incidence of synergy was found after 24 h with gentamicin (90% of strains), followed by ceftriaxone (88%), rifampin and meropenem (each 65%), cefepime (45%), and ciprofloxacin (38%) for combinations tested at or below the intermediate breakpoint for each agent.
Characterization of UDP-Glucose Dehydrogenase and UDP-Glucose Pyrophosphorylase Mutants ofProteus mirabilis: Defectiveness in Polymyxin B Resistance, Swarming, and Virulence
Authors: Jiang Sin-Sien , Lin Tzu-Yi , Wang Won-Bo , Liu Ming-Che , Hsueh Po-Ren , Liaw Shwu-Jen
Published: February 2010

Proteus mirabilisis known to be highly resistant to the action of polymyxin B (PB). However, the mechanism underlying PB resistance is not clear. In this study, we used Tn5transposon mutagenesis to identify genes that may affect PB resistance inP. mirabilis. Two genes,ugdandgalU, which may encode UDP-glucose dehydrogenase (Ugd) and UDP-glucose pyrophosphorylase (GalU), respectively, were identified. Knockout mutants ofugdandgalUwere found to be extremely sensitive to PB, presumably because of alterations in lipopolysaccharide (LPS) structure and cell surface architecture in these mutants. These mutants were defective in swarming, expressed lower levels of virulence factor hemolysin, and had lower cell invasion ability. Complementation of theugdorgalUmutant with the full-lengthugdorgalUgene, respectively, led to the restoration of wild-type phenotypic traits. Interestingly, we found that the expression of Ugd and GalU was induced by PB through RppA, a putative response regulator of the bacterial two-component system that we identified previously. Mutation in eitherugdorgalUled to activation of RpoE, an extracytoplasmic function sigma factor that has been shown to be activated by protein misfolding and alterations in cell surface structure in other bacteria. Activation of RpoE or RpoE overexpression was found to cause inhibition of FlhDC and hemolysin expression. To our knowledge, this is the first report describing the roles and regulation of Ugd and GalU inP. mirabilis.
Single-Dose Pharmacokinetics of Famciclovir in Infants and Population Pharmacokinetic Analysis in Infants and Children
Authors: Blumer Jeffrey , Rodriguez Adib , Sánchez Pablo J. , Sallas William , Kaiser Guenther , Hamed Kamal
Published: February 2010

A multicenter, open-label study evaluated the single-dose pharmacokinetics and safety of a pediatric oral famciclovir (prodrug of penciclovir) formulation in infants aged 1 to 12 months with suspicion or evidence of herpes simplex virus infection. Individualized single doses of famciclovir based on the infant's body weight ranged from 25 to 175 mg. Eighteen infants were enrolled (1 to <3 months old [
n
= 8], 3 to <6 months old [
n
= 5], and 6 to 12 months old [
n
= 5]). Seventeen infants were included in the pharmacokinetic analysis; one infant experienced immediate emesis and was excluded. Mean
C
max
and AUC
0-6
values of penciclovir in infants <6 months of age were ∼3- to 4-fold lower than those in the 6- to 12-month age group. Specifically, mean AUC
0-6
was 2.2 μg·h/ml in infants aged 1 to <3 months, 3.2 μg·h/ml in infants aged 3 to <6 months, and 8.8 μg·h/ml in infants aged 6 to 12 months. These data suggested that the dose administered to infants <6 months was less than optimal. Eight (44.4%) infants experienced at least one adverse event with gastrointestinal events reported most commonly. An updated pharmacokinetic analysis was conducted, which incorporated the data in infants from the present study and previously published data on children 1 to 12 years of age. An eight-step dosing regimen was derived that targeted exposure in infants and children 6 months to 12 years of age to match the penciclovir AUC seen in adults after a 500-mg dose of famciclovir.
Inhibitors of
Leishmania
GDP-Mannose Pyrophosphorylase Identified by High-Throughput Screening of Small-Molecule Chemical Library
Authors: Lackovic Kurt , Parisot John P. , Sleebs Nerida , Baell Jonathan B. , Debien Laurent , Watson Keith G. , Curtis Joan M. , Handman Emanuela , Street Ian P. , Kedzierski Lukasz
Published: February 2010

The current treatment for leishmaniasis is based on chemotherapy, which relies on a handful of drugs with serious limitations, such as high cost, toxicity, and a lack of efficacy in regions of endemicity. Therefore, the development of new, effective, and affordable antileishmanial drugs is a global health priority.
Leishmania
synthesizes a range of mannose-rich glycoconjugates that are essential for parasite virulence and survival. A prerequisite for glycoconjugate biosynthesis is the conversion of monosaccharides to the activated mannose donor, GDP-mannose, the product of a reaction catalyzed by GDP-mannose pyrophosphorylase (GDP-MP). The deletion of the gene encoding GDP-MP in
Leishmania
led to a total loss of virulence, indicating that the enzyme is an ideal drug target. We developed a phosphate sensor-based high-throughput screening assay to quantify the activity of GDP-MP and screened a library containing ∼80,000 lead-like compounds for GDP-MP inhibitors. On the basis of their GDP-MP inhibitory properties and chemical structures, the activities of 20 compounds which were not toxic to mammalian cells were tested against ex vivo amastigotes and in macrophage amastigote assays. The most potent compound identified in the primary screen (compound 3), a quinoline derivative, demonstrated dose-dependent activity in both assays (50% inhibitory concentration = 21.9 μM in the macrophage assay) and was shown to be nontoxic to human fibroblasts. In order to elucidate signs of an early structure-activity relationship (SAR) for this class of compounds, we obtained and tested analogues of compound 3 and undertook limited medicinal chemistry optimization, which included the use of a number of SAR probes of the piperazinyl aryl substituent of compound 3. We have identified novel candidate compounds for the design and synthesis of antileishmanial therapeutics.
Increased Tolerance to Artemisinin in
Plasmodium falciparum
Is Mediated by a Quiescence Mechanism
Authors: Witkowski Benoit , Lelièvre Joel , López Barragán María José , Laurent Victor , Su Xin-zhuan , Berry Antoine , Benoit-Vical Françoise
Published: February 2010

Artemisinin (ART)-based combination therapies (ACTs) are the first-line drugs—and often the last treatments—that can effectively cure
Plasmodium falciparum
infections. Unfortunately, the decreased clinical efficacy of artesunate, one of the major ART derivatives, was recently reported along the Thailand-Cambodia border. Through long-term artemisinin pressure
in vitro
, we have obtained an ART-tolerant strain that can survive extremely high doses of ART. We showed that drug pressure could induce a subpopulation of ring stages into developmental arrest, which can explain the ART tolerance in
P. falciparum
. We also observed interesting transcriptomic modifications possibly associated with the acquisition of ART tolerance. These modifications include the overexpression of heat shock and erythrocyte surface proteins and the downexpression of a cell cycle regulator and a DNA biosynthesis protein. This study highlights a new phenomenon in the
Plasmodium
response to ART that may explain the delayed clearance of parasites after artesunate treatment observed on the Thailand-Cambodia border and that provides important information for achieving a better understanding of the mechanisms of antimalarial resistance.
Upregulated Expression of B-Cell Antigen Family Tandem Repeat Proteins byLeishmaniaAmastigotes
Authors: Goto Yasuyuki , Carter Darrick , Guderian Jeffrey , Inoue Noboru , Kawazu Shin-Ichiro , Reed Steven G.
Published: February 2010

Proteins with tandem repeat (TR) domains have been found in various protozoan parasites, and they are often targets of B-cell responses. Through systematic analyses of whole proteomes, we recently demonstrated that two trypanosomatid parasites,Leishmania infantumandTrypanosoma cruzi, are rich in antigenic proteins with large TR domains. However, the reason that these proteins are antigenic was unclear. Here, by performing molecular, immunological, and bioinformatic characterizations ofLeishmaniaTR proteins, we found two possible factors affecting the antigenicity of these proteins; one factor is their fundamental composition as TR proteins, and the other is regulation of their expression by parasites. Enzyme-linked immunosorbent assays (ELISAs) using recombinant proteins revealed that the copy number of the repeat affects the affinity of binding between antigens and antibodies, as expected based on thermodynamic binding kinetics. Other than containing TR domains, the TR proteins do not share characteristics, such as sequence similarity or biased cellular location predicted by the presence of a signal sequence(s) and/or a transmembrane domain(s). However, the TR proteome contained a higher percentage of proteins upregulated in amastigotes than the whole proteome, and upregulated expression of a TR protein seemed to affect its antigenicity. These results indicate thatLeishmaniaparasites actively utilize the TR protein family for parasitism in mammalian hosts.
The Yersiniabactin Transport System Is Critical for the Pathogenesis of Bubonic and Pneumonic Plague
Authors: Fetherston Jacqueline D. , Kirillina Olga , Bobrov Alexander G. , Paulley James T. , Perry Robert D.
Published: February 2010

Iron acquisition from the host is an important step in the pathogenic process. While
Yersinia pestis
has multiple iron transporters, the yersiniabactin (Ybt) siderophore-dependent system plays a major role in iron acquisition
in vitro
and
in vivo
. In this study, we determined that the Ybt system is required for the use of iron bound by transferrin and lactoferrin and examined the importance of the Ybt system for virulence in mouse models of bubonic and pneumonic plague.
Y. pestis
mutants unable to either transport Ybt or synthesize the siderophore were both essentially avirulent via subcutaneous injection (bubonic plague model). Surprisingly, via intranasal instillation (pneumonic plague model), we saw a difference in the virulence of Ybt biosynthetic and transport mutants. Ybt biosynthetic mutants displayed an ∼24-fold-higher 50% lethal dose (LD
50
) than transport mutants. In contrast, under iron-restricted conditions
in vitro
, a Ybt transport mutant had a more severe growth defect than the Ybt biosynthetic mutant. Finally, a Δ
pgm
mutant had a greater loss of virulence than the Ybt biosynthetic mutant, indicating that the 102-kb
pgm
locus encodes a virulence factor, in addition to Ybt, that plays a role in the pathogenesis of pneumonic plague.
Intracellular Invasion by
Orientia tsutsugamushi
Is Mediated by Integrin Signaling and Actin Cytoskeleton Rearrangements
Authors: Cho Bon-A , Cho Nam-Hyuk , Seong Seung-Yong , Choi Myung-Sik , Kim Ik-Sang
Published: February 2010

Orientia tsutsugamushi
, the causative agent of scrub typhus, is an obligate intracellular pathogen. Previously, we reported that the 56-kDa type-specific antigen (TSA56), a major outer membrane protein of
O. tsutsugamushi
, binds to fibronectin and facilitates bacterial entry into the host cell, potentially via an interaction with integrins. Here, we demonstrated that
O. tsutsugamushi
colocalizes with integrin α5β1 and activates integrin signaling effectors, including focal adhesion kinase, Src kinase, and RhoA GTPase, and also recruits signaling adaptors, such as talin and paxillin, to the site of infection. Inhibition of protein tyrosine kinases or RhoA reduced intracellular invasion. We also observed substantial actin reorganization and membrane protrusions at the sites of infection of nonphagocytic host cells. Finally, we identified a region in the extracellular domain of TSA56 that binds to fibronectin. A peptide containing this region was able to significantly reduce bacterial invasion. Taken together, these results clearly indicate that
O. tsutsugamushi
exploits integrin-mediated signaling and the actin cytoskeleton for invasion of eukaryotic host cells.
Contraction-related stimuli regulate GLUT4 traffic in C2C12-GLUT4mycskeletal muscle cells
Authors: Niu Wenyan , Bilan Philip J. , Ishikura Shuhei , Schertzer Jonathan D. , Contreras-Ferrat Ariel , Fu Zhengxiang , Liu Jie , Boguslavsky Shlomit , Foley Kevin P. , Liu Zhi , Li Jinru , Chu Guilan , Panakkezhum Thomas , Lopaschuk Gary D. , Lavandero Sergio , Yao Zhi , Klip Amira
Published: February 2010

Muscle contraction stimulates glucose uptake acutely to increase energy supply, but suitable cellular models that faithfully reproduce this complex phenomenon are lacking. To this end, we have developed a cellular model of contracting C2C12myotubes overexpressing GLUT4 with an exofacial myc-epitope tag (GLUT4 myc) and explored stimulation of GLUT4 traffic by physiologically relevant agents. Carbachol (an acetylcholine receptor agonist) induced a gain in cell surface GLUT4 myc that was mediated by nicotinic acetylcholine receptors. Carbachol also activated AMPK, and this response was sensitive to the contractile myosin ATPase inhibitor N-benzyl- p-toluenesulfonamide. The gain in surface GLUT4 myc elicited by carbachol or by the AMPK activator 5-amino-4-carboxamide-1 β-ribose was sensitive to chemical inhibition of AMPK activity by compound C and partially reduced by siRNA-mediated knockdown of AMPK catalytic subunits or LKB1. In addition, the carbachol-induced gain in cell surface GLUT4 myc was partially sensitive to chelation of intracellular calcium with BAPTA-AM. However, the carbachol-induced gain in cell surface GLUT4 myc was not sensitive to the CaMKK inhibitor STO-609 despite expression of both isoforms of this enzyme and a rise in cytosolic calcium by carbachol. Therefore, separate AMPK- and calcium-dependent signals contribute to mobilizing GLUT4 in response to carbachol, providing an in vitro cell model that recapitulates the two major signals whereby acute contraction regulates glucose uptake in skeletal muscle. This system will be ideal to further analyze the underlying molecular events of contraction-regulated GLUT4 traffic.
Cholecystokinin as a regulator of cardiac function and postprandial gastrointestinal blood flow in rainbow trout (Oncorhynchus mykiss)
Authors: Seth Henrik , Gräns Albin , Axelsson Michael
Published: February 2010

We have studied the potential role of CCK as a regulator/modulator of the postprandial increase in gastrointestinal blood flow. Rainbow trout ( Oncorhynchus mykiss ) were instrumented with pulsed Doppler flow probes to measure the effects of CCK on cardiac output and gastrointestinal blood flow. Furthermore, vascular preparations were used to study the direct effects of CCK on the vessels. In addition, we used in situ perfused hearts to further study the effects of CCK on the cardiovascular system. When the sulfated form of CCK-8 was injected at a physiological concentration (0.19 pmol/kg) in vivo, there was a significant increase in the gastrointestinal blood flow (18 ± 4%). This increase in gastrointestinal blood flow was followed by a subsequent increase in cardiac output (30 ± 6%). When the dose was increased to 0.76 pmol/kg, there was only a 14 ± 6% increase in gastrointestinal blood flow; possibly due to a dose-dependent increase in the gill vascular resistance as previously reported or a direct effect on the heart. Nevertheless, CCK did not affect the isolated vessel preparations, and thus, it seems unlikely that CCK has a direct effect on the blood vessels of the second or third order. CCK did, however, have profound effects on the dynamics of the heart, and without a change in cardiac output, there was a significant increase in the amplitude (59 ± 4%) and rate (dQ/d t: 55 ± 4%; -dQ/d t: 208 ± 49%) of the phasic flow profile. If and how this might be coupled to a postprandial gastrointestinal hyperemia remains to be determined. We conclude that CCK has the potential as a regulator of the postprandial gastrointestinal blood flow in fish and most likely has its effect by inducing a gastrointestinal hyperemia. The mechanism by which CCK acts is at present unknown.
Regulation of renal tubular glucose reabsorption by Akt2/PKBβ
Authors: Kempe Daniela S. , Siraskar Gulab , Fröhlich Henning , Umbach Anja T. , Stübs Michael , Weiss Florian , Ackermann Teresa F. , Völkl Harald , Birnbaum Morris J. , Pearce David , Föller Michael , Lang Florian
Published: February 2010

Akt/PKB is known to regulate the facilitative glucose carrier GLUT4. Nothing is known, however, of the role of Akt/PKB in the regulation of renal epithelial transport. To explore whether Akt2/PKBβ influences the Na+-coupled glucose cotransporter SGLT1, human SGLT1 was expressed in Xenopus laevis oocytes with or without Akt/PKB, and electrogenic glucose transport was determined by dual-electrode voltage clamp. The coexpression of Akt/PKB in SGLT1-expressing oocytes was followed by an increase in glucose-induced currents. To study the functional significance of Akt/PKB-sensitive renal glucose transport, further experiments were performed in gene-targeted mice lacking functional Akt2/PKBβ ( akt2−/−) and in their wild-type littermates ( akt2+/+). Plasma glucose concentration was significantly higher in akt2−/−mice than in akt2+/+mice but was virtually identical to the plasma glucose concentration in fructose-treated akt2+/+mice. Urinary glucose excretion was significantly higher in akt2−/−mice compared with akt2+/+mice with or without fructose treatment. Moreover, the glucose-induced depolarization of proximal tubular cells was significantly smaller in isolated, perfused renal tubules from akt2−/−mice than in those from akt2+/+mice. In conclusion, Akt2/PKBβ plays a role in the regulation of renal glucose transport.
Self-Motion and the Shaping of Sensory Signals
Authors: Jenks Robert A. , Vaziri Ashkan , Boloori Ali-Reza , Stanley Garrett B.
Published: February 2010

Sensory systems must form stable representations of the external environment in the presence of self-induced variations in sensory signals. It is also possible that the variations themselves may provide useful information about self-motion relative to the external environment. Rats have been shown to be capable of fine texture discrimination and object localization based on palpation by facial vibrissae, or whiskers, alone. During behavior, the facial vibrissae brush against objects and undergo deflection patterns that are influenced both by the surface features of the objects and by the animal's own motion. The extent to which behavioral variability shapes the sensory inputs to this pathway is unknown. Using high-resolution, high-speed videography of unconstrained rats running on a linear track, we measured several behavioral variables including running speed, distance to the track wall, and head angle, as well as the proximal vibrissa deflections while the distal portions of the vibrissae were in contact with periodic gratings. The measured deflections, which serve as the sensory input to this pathway, were strongly modulated both by the properties of the gratings and the trial-to-trial variations in head-motion and locomotion. Using presumed internal knowledge of locomotion and head-rotation, gratings were classified using short-duration trials (<150 ms) from high-frequency vibrissa motion, and the continuous trajectory of the animal's own motion through the track was decoded from the low frequency content. Together, these results suggest that rats have simultaneous access to low- and high-frequency information about their environment, which has been shown to be parsed into different processing streams that are likely important for accurate object localization and texture coding.
Structural and Raman Vibrational Studies ofCeO2‐Bi2O3 Oxide System
Authors: Bourja L. , Bakiz B. , Benlhachemi A. , Ezahri M. , Valmalette J. C. , Villain S. , Gavarri J. R.
Published: February 2010

A series of ceramics samples belonging to the CeO2‐Bi2O3 phase system have been prepared via a coprecipitation route. The crystallized phases were obtained by heating the solid precursors at 600∘C for 6 hours, then quenching the samples. X‐ray diffraction analyses show that for x < 0.20 a solid solution Ce1−xBixO2−x/2 with fluorine structure is formed. For x ranging between 0.25 and 0.7, a tetragonal β′ phase coexisting with the FCC solid solution is observed. For x ranging between 0.8 and 0.9, a new tetragonal β phase appears. The β′ phase is postulated to be a superstructure of the β phase. Finally, close to x = 1, the classical monoclinic α Bi2O3 structure is observed. Raman spectroscopy confirms the existence of the phase changes as x varies between 0 and 1.
Body Weight Control by a High-Carbohydrate/Low-Fat Diet Slows the Progression of Diabetic Kidney Damage in an Obese, Hypertensive, Type 2 Diabetic Rat Model
Authors: Ohtomo Shuichi , Izuhara Yuko , Nangaku Masaomi , Dan Takashi , Ito Sadayoshi , de Strihou Charles van Ypersele , Miyata Toshio
Published: February 2010

Obesity is one of several factors implicated in the genesis of diabetic nephropathy (DN). Obese, hypertensive, type 2 diabetic rats SHR/NDmcr-cp were given, for 12 weeks, either a normal, middle-carbohydrate/middle-fat diet (MC/MF group) or a high-carbohydrate/low-fat diet (HC/LF group). Daily caloric intake was the same in both groups. Nevertheless, the HC/LF group gained less weight. Despite equivalent degrees of hypertension, hyperglycemia, hyperlipidemia, hyperinsulinemia, and even a poorer glycemic control, the HC/LF group had less severe renal histological abnormalities and a reduced intrarenal advanced glycation and oxidative stress. Mediators of the renoprotection, specifically linked to obesity and body weight control, include a reduced renal inflammation and TGF-beta expression, together with an enhanced level of adiponectin. Altogether, these data identify a specific role of body weight control by a high-carbohydrate/low-fat diet in the progression of DN. Body weight control thus impacts on local intrarenal advanced glycation and oxidative stress through inflammation and adiponectin levels.
Approximating Fixed Points of Some Maps in Uniformly Convex Metric Spaces
Authors: Khan AbdulRahim , Fukhar-ud-din Hafiz , Domlo AbdulAziz
Published: February 2010

We study strong convergence of the Ishikawa iterates of qasi-nonexpansive (generalized nonexpansive) maps and some related results in uniformly convex metric spaces. Our work improves and generalizes the corresponding results existing in the literature for uniformly convex Banach spaces.
Notes on the Essential System to Acquire Information
Authors: Rocchi Paolo
Published: February 2010

This paper introduces a short survey on recent information theories and reviews some critical notes expressed on quantum information. The severe difficulties emerging from the literature lead us to argue about the way to follow, and in a preliminary stage, we consider how to proceed in order to provide a reasonable contribution to the conceptualization of information in classical and quantum physics. We conclude that we should go toward the essential elements of the system that acquire information and should define the common components of the measurement processes. In this way we should be able to establish fundamental properties and to circumvent tricky difficulties arisen by the concept of the observer and the variety of interferences that disturb the acquisition of information. Universal experience shows how sharpness is the indispensable feature of detected signals and we calculate the discernability of observables using various mathematical formalisms. The present logical frame brings evidence on how information is not an absolute quantity, and we close with a few notes on the information relativism which modern literature tackles from the operational stance and the philosophical stance.
The Role of Dysregulated Glucose Metabolism in Epithelial Ovarian Cancer
Authors: Kellenberger L. D. , Bruin J. E. , Greenaway J. , Campbell N. E. , Moorehead R. A. , Holloway A. C. , Petrik J.
Published: February 2010

Epithelial ovarian cancer (EOC) is the most lethal gynecologic cancer and also one of the most poorly understood. Other health issues that are affecting women with increasing frequency are obesity and diabetes, which are associated with dysglycemia and increased blood glucose. The Warburg Effect describes the ability of fast-growing cancer cells to preferentially metabolize glucose via anaerobic glycolysis rather than oxidative phosphorylation. Recent epidemiological studies have suggested a role for hyperglycemia in the pathogenesis of a number of cancers. If hyperglycemia contributes to tumour growth and progression, then it is intuitive that antihyperglycemic drugs may also have an important antitumour role. Preliminary reports suggest that these drugs not only reduce available plasma glucose, but also have direct effects on cancer cell viability through modification of molecular energy-sensing pathways. This review investigates the effect that hyperglycemia may have on EOC and the potential of antihyperglycemic drugs as therapeutic adjuncts.
Discretizing LTI Descriptor (Regular) Differential Input Systems with Consistent Initial Conditions
Authors: Karageorgos Athanasios D. , Pantelous Athanasios A. , Kalogeropoulos Grigoris I.
Published: February 2010

A technique for discretizing efficiently the solution of a Linear descriptor (regular) differential input system with consistent initial conditions, and Time-Invariant coefficients (LTI) is introduced and fully discussed. Additionally, an upper bound for the error ‖x¯(kT)−x¯k‖ that derives from the procedure of discretization is also provided. Practically speaking, we are interested in such kind of systems, since they are inherent in many physical, economical and engineering phenomena.
TRF1 Mediates Mitotic Abnormalities Induced by Aurora-A Overexpression
Authors: Ohishi Tomokazu , Hirota Toru , Tsuruo Takashi , Seimiya Hiroyuki
Published: February 2010

Aurora-A, a conserved serine-threonine kinase, plays essential roles in mitosis. Aberrant upregulation of Aurora-A perturbs proper mitotic progression and results in a generation of multinucleated cells with centrosome amplification. The molecular mechanisms for these mitotic defects remain elusive. Here, we show that the overexpressed Aurora-A–induced mitotic defects depend on the telomeric protein TRF1. Live and fixed cell analyses revealed that Aurora-A overexpression in HeLa cells compromises chromosome biorientation, which leads to cytokinetic failure and tetraploidization with increased centrosome numbers. TRF1 depletion by small interfering RNAs or by tankyrase-1 overexpression suppresses Aurora-A–induced occurrence of unaligned chromosomes in metaphase, thus preventing the subsequent abnormalities. We found that Aurora-A binds and phosphorylates TRF1. When TRF1 knockdown cells are complemented with wild-type TRF1, Aurora-A–induced mitotic defects recur. By contrast, a TRF1 mutant that is not phosphorylatable by Aurora-A does not restore such Aurora-A–induced phenotype. We propose that TRF1 phosphorylation by excessive Aurora-A may provoke abnormal mitosis and chromosomal instability. Cancer Res; 70(5); 2041–52
Thioredoxin Reductase-1 Mediates Curcumin-Induced Radiosensitization of Squamous Carcinoma Cells
Authors: Javvadi Prashanthi , Hertan Lauren , Kosoff Rachelle , Datta Tatini , Kolev Johann , Mick Rosemarie , Tuttle Stephen W. , Koumenis Constantinos
Published: February 2010

Curcumin, a plant polyphenol, is a widely studied chemopreventive agent with demonstrated antitumor activities in preclinical studies and low toxicity profiles in multiple clinical trials against human malignancies. We previously showed that curcumin radiosensitizes cervical tumor cells without increasing the cytotoxic effects of radiation on normal human fibroblasts. Here we report that an inhibitory activity of curcumin on the antioxidant enzyme thioredoxin reductase-1 (TxnRd1) is required for curcumin-mediated radiosensitization of squamous carcinoma cells. Stable knockdown of TxnRd1 in both HeLa and FaDu cells nearly abolished curcumin-mediated radiosensitization. TxnRd1 knockdown cells showed decreased radiation-induced reactive oxygen species and sustained extracellular signal-regulated kinase 1/2 activation, which we previously showed was required for curcumin-mediated radiosensitization. Conversely, overexpressing catalytically active TxnRd1 in HEK293 cells, with low basal levels of TxnRd1, increased their sensitivity to curcumin alone and to the combination of curcumin and ionizing radiation. These results show the critical role of TxnRd1 in curcumin-mediated radiosensitization and suggest that TxnRd1 levels in tumors could have clinical value as a predictor of response to curcumin and radiotherapy. Cancer Res; 70(5); 1941–50
An Oncogenic Role for ETV1 in Melanoma
Authors: Jané-Valbuena Judit , Widlund Hans R. , Perner Sven , Johnson Laura A. , Dibner Aurora C. , Lin William M. , Baker Alissa C. , Nazarian Rosalynn M. , Vijayendran Krishna G. , Sellers William R. , Hahn William C. , Duncan Lyn M. , Rubin Mark A. , Fisher David E. , Garraway Levi A.
Published: February 2010

Copy gains involving chromosome 7p represent one of the most common genomic alterations found in melanomas, suggesting the presence of “driver” cancer genes. We identified several tumor samples that harbored focal amplifications situated at the peak of common chromosome 7p gains, in which the minimal common overlapping region spanned the ETV1 oncogene. Fluorescence in situ hybridization analysis revealed copy gains spanning the ETV1 locus in >40% of cases, with ETV1 amplification (>6 copies/cell) present in 13% of primary and 18% of metastatic melanomas. Melanoma cell lines, including those with ETV1 amplification, exhibited dependency on ETV1 expression for proliferation and anchorage-independent growth. Moreover, overexpression of ETV1 in combination with oncogenic NRASG12D transformed primary melanocytes and promoted tumor formation in mice. ETV1 overexpression elevated microphthalmia-associated transcription factor expression in immortalized melanocytes, which was necessary for ETV1-dependent oncogenicity. These observations implicate deregulated ETV1 in melanoma genesis and suggest a pivotal lineage dependency mediated by oncogenic ETS transcription factors in this malignancy. Cancer Res; 70(5); 2075–84
HER Kinase Axis Receptor Dimer Partner Switching Occurs in Response to EGFR Tyrosine Kinase Inhibition despite Failure to Block Cellular Proliferation
Authors: Jain Anjali , Penuel Elicia , Mink Sheldon , Schmidt Joanna , Hodge Amanda , Favero Kristin , Tindell Charles , Agus David B.
Published: February 2010

The human epidermal receptor (HER) axis consists of a dynamic, interconnected family of receptors that make critical contributions to a number of malignancies. Therapeutics targeting epidermal growth factor receptor (EGFR) are unable to effectively inhibit tumor growth in a majority of cases. These tumors are assumed to possess primary resistance to anti-EGFR therapies, but the consequence of inhibiting EGFR in these tumors is unclear. We established isogenic cell lines by prolonged gefitinib treatment at concentrations that are in excess of that which is required for complete EGFR kinase inhibition but only minimally affected growth. Subsequently, we monitored the ligand-dependent HER profiles based on receptor expression, phosphorylation, and dimerization in conjunction with measurements of cellular susceptibility to gefitinib. Chronic EGFR kinase inhibition rapidly switched the HER network from dependence on EGFR to HER2. However, both receptors activated the critical signaling proteins AKT and mitogen-activated protein kinase, and in both cases, HER3 was the common association partner. Remarkably, the switch in receptor dimers caused diminished susceptibility to EGFR-targeted inhibitors gefitinib and cetuximab but acquired susceptibility to the HER2-targeted inhibitor pertuzumab. Overall, our study indicates that the EGFR pathway is responsive to EGFR inhibiting therapies that are not dependent on EGFR for their growth and survival, thus challenging the current definition of primary therapeutic resistance. Furthermore, EGFR kinase inhibition induces HER kinase receptors to engage in alternative dimerization that can ultimately influence therapeutic selection and responsiveness. Cancer Res; 70(5); 1989–99
Evaluation of the ETS-Related Gene mRNA in Urine for the Detection of Prostate Cancer
Authors: Rice Kevin R. , Chen Yongmei , Ali Amina , Whitman Eric J. , Blase Amy , Ibrahim Mona , Elsamanoudi Sally , Brassell Stephen , Furusato Bungo , Stingle Norbert , Sesterhenn Isabell A. , Petrovics Gyorgy , Miick Siobhan , Rittenhouse Harry , Groskopf Jack , McLeod David G. , Srivastava Shiv
Published: February 2010

Purpose: Prevalent gene fusions in prostate cancer involve androgen-regulated promoters (primarily TMPRSS2) and ETS transcription factors (predominantly ETS-regulated gene (ERG)], which result in tumor selective overexpression of ERG in two thirds of patients. Because diverse genomic fusion events lead to ERG overexpression in prostate cancer, we reasoned that it may be more practical to capture such alterations using an assay targeting ERG sequences retained in such gene fusions. This study evaluates the potential of an assay quantitating ERG mRNA in post–digital rectal exam (DRE) urine for improving prostate cancer detection.

Experimental Design: Patients scheduled to undergo transrectal ultrasound-guided needle biopsy of the prostate were prospectively enrolled. On the day of biopsy, patients provided a urine sample immediately following a DRE. Urine ERG mRNA was measured and normalized to urine prostate-specific antigen (PSA) mRNA using the DTS 400 system. Demographic traits, clinical characteristics and biopsy results were analyzed for association with urine ERG score.

Results: The study was conducted on 237 patients. Prostate cancer was shown on biopsy in 40.9% of study subjects. A higher urine ERG score associated significantly with malignancy on biopsy (P = 0.0145), but not with clinical stage or Gleason score. Urine ERG score performed best in Caucasians and in men with a PSA of ≤4 ng/mL (area under the curve = 0.8).

Conclusions: A higher urine ERG score in post-DRE urine is associated with the diagnosis of prostate cancer on biopsy. Urine ERG score performed particularly well in men with a PSA of ≤4.0 ng/mL, a segment of the screening population in which further diagnostic markers are needed to determine in whom biopsy should be done. Clin Cancer Res; 16(5); 1572–6
Defucosylated Humanized Anti-CCR4 Monoclonal Antibody KW-0761 as a Novel Immunotherapeutic Agent for Adult T-cell Leukemia/Lymphoma
Authors: Ishii Toshihiko , Ishida Takashi , Utsunomiya Atae , Inagaki Atsushi , Yano Hiroki , Komatsu Hirokazu , Iida Shinsuke , Imada Kazunori , Uchiyama Takashi , Akinaga Shiro , Shitara Kenya , Ueda Ryuzo
Published: February 2010

Purpose: Adult T-cell leukemia/lymphoma (ATLL) has a very poor prognosis. We have developed the humanized defucosylated anti–CC chemokine receptor 4 (CCR4) monoclonal antibody KW-0761 as a next generation immunotherapeutic agent. The first aim of the present study was to evaluate whether the antitumor activity of KW-0761 would likely be sufficient for therapeutic clinical application against ATLL. The second aim was to fully elucidate the mechanism of antibody-dependent cellular cytotoxicity (ADCC) mediated by this defucosylated monoclonal antibody.

Experimental Design: The antitumor activity of KW-0761 against ATLL cell lines was evaluated in vitro using human cells and in mice in vivo. Primary ATLL cells from 23 patients were evaluated for susceptibility to autologous ADCC with KW-0761 by two independent methods.

Results: KW-0761 showed potent antitumor activity against ATLL cell lines both in vitro and in the ATLL mouse model in vivo. In addition, KW-0761 showed potent antitumor activity mediated by highly enhanced ADCC against primary ATLL cells both in vitro and ex vivo in an autologous setting. The degree of KW-0761 ADCC against primary ATLL cells in an autologous setting was mainly determined by the amount of effector natural killer cells present, but not the amount of the target molecule CCR4 on the ATLL cell surface.

Conclusion: KW-0761 should be sufficiently active for therapeutic clinical application for ATLL. In addition, combination treatment strategies that augment natural killer cell activity should be promising for amplifying the effect of KW-0761. In the near future, the actual efficacy of KW-0761 will be established in pivotal clinical trials. Clin Cancer Res; 16(5); 1520–31
Preclinical Investigation of PEGylated Tumor Necrosis Factor α in Dogs with Spontaneous Tumors: Phase I Evaluation
Authors: Thamm Douglas H. , Kurzman Ilene D. , Clark Mike A. , Ehrhart E.J. , Kraft Susan L. , Gustafson Daniel L. , Vail David M.
Published: February 2010

Purpose: Tumor necrosis factor-α (TNF) is a cytokine with potent antitumor activity; however, toxicity and short half-life have limited its utility. Polyethylene glycol (PEG) conjugation of biotherapeutics can decrease immunogenicity while improving bioactivity and half-life. PEGylation of TNF (PEG-TNF) significantly improved half-life and toxicity in mice, resulting in enhanced antitumor activity. This study characterized toxicity, biological effect, and antitumor activity of PEG-TNF in pet dogs with spontaneous cancer.

Experimental Design: A phase I clinical trial enrolled dogs with measurable tumors in which standard therapy had failed or been declined. Physiologic, hematologic, and biochemical parameters were evaluated and tumor biopsies obtained serially. A subset of patients underwent serial dynamic contrast-enhanced magnetic resonance imaging.

Results: Fifteen dogs were enrolled at doses from 20.0 to 30.0 μg/kg. Dose-limiting toxicity at 30.0 μg/kg consisted of vascular leak in one and hypotension/coagulopathy in one, establishing 26.7 μg/kg as the maximum tolerated dose. Mean elimination half-life was 15.3 ± 4.9 hours. Biological activity (transient fever and leukopenia, increased tumor inflammation, and necrosis) was observed at all dosages. A significant increase in tumor blood flow was observed with dynamic contrast-enhanced magnetic resonance imaging. Minor/transient antitumor responses were observed in dogs with melanoma, squamous cell carcinoma, and mammary carcinoma, and a partial response was observed in a dog with angiosarcoma.

Conclusions: Using a clinically relevant, spontaneous large animal model of neoplasia, we have shown that biologically effective doses of PEG-TNF can be administered safely, and that PEG-TNF administration is associated with encouraging biological activity. These results justify the clinical evaluation of PEG-TNF in human cancer. Clin Cancer Res; 16(5); 1498–508
IDH1 and IDH2 Mutations Are Prognostic but not Predictive for Outcome in Anaplastic Oligodendroglial Tumors: A Report of the European Organization for Research and Treatment of Cancer Brain Tumor Group
Authors: van den Bent Martin J. , Dubbink Hendrikus J. , Marie Yannick , Brandes Alba A. , Taphoorn Martin J.B. , Wesseling Pieter , Frenay Marc , Tijssen Cees C. , Lacombe Denis , Idbaih Ahmed , van Marion Ronald , Kros Johan M. , Dinjens Winand N.M. , Gorlia Thierry , Sanson Marc
Published: February 2010

Purpose: Recent studies have shown the prognostic significance of IDH1 mutations in glioma. It is yet unclear if IDH1 mutations are predictive for outcome to chemotherapy. We determined the effect of IDH1 mutations on progression-free survival and overall survival (OS), and its correlation with other clinical and molecular features in the prospective randomized European Organization for Research and Treatment of Cancer study 26951 on adjuvant procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea, and vincristine (PCV) in anaplastic oligodendroglioma.

Experimental Design: IDH1 and IDH2 alterations of the mutational hotspot codons R132 and R172 were assessed by the bidirectional cycle sequencing of PCR-amplified fragments. MGMT promoter methylation was assessed using methylation-specific multiplex ligation–dependant probe amplification based on methylation-sensitive restriction analysis. Loss of chromosomes 1p, 19q, 10, and 10q and the gain of 7 and the EGFR gene were assessed with fluorescence in situ hybridization.

Results: From 159 patients, sufficient material was available for IDH1 analysis. In 151 and 118 of these patients, respectively, the 1p/19q status and the MGMT promoter methylation status were known. In 73 cases (46%), an IDH1 mutation was found and only one IDH2 mutation was identified. The presence of IDH1 mutations correlated with 1p/19q codeletion and MGMT promoter methylation, and inversely correlated with loss of chromosome 10, EGFR amplification, polysomy of chromosome 7, and the presence of necrosis. IDH1 mutations were found to be prognostic in the radiotherapy- and the radiotherapy/PCV-treated patients, for both progression-free survival and OS. With Cox proportional hazard modeling for OS with stepwise selection, IDH1 mutations and 1p/19q codeletion but not MGMT promoter methylation were independent prognostic factors.

Conclusion: In this homogeneously treated group of anaplastic oligodendroglioma patients, the presence of IDH1 mutations was found to carry a very strong prognostic significance for OS but without evidence of a predictive significance for outcome to PCV chemotherapy. IDH1 mutations were strongly associated with 1p/19q codeletion and MGMT promoter methylation. Clin Cancer Res; 16(5); 1597–604
Oral Anticoagulation in Nonvalvular Atrial Fibrillation in Clinical Practice: Impact of CHADS2 Score on Outcome
Authors: Ruiz Ortiz Martín , Romo Elías , Mesa Dolores , Delgado Mónica , Anguita Manuel , Castillo Juan C. , Arizón José M. , Suárez de Lezo José
Published: February 2010

Objectives: CHADS2 score predicts embolic risk in patients with nonvalvular atrial fibrillation (NVAF), but also bleeding risk in patients receiving oral anticoagulation (OAC). Our objective is to analyze the effectiveness and safety of OAC in patients with NVAF in daily clinical practice, according to embolic risk evaluated by means of CHADS2 score. Methods: All consecutive outpatients with permanent NVAF seen at 2 cardiology clinics were prospectively followed for embolic events (transient ischemic attack, ischemic stroke, peripheral embolism) and severe bleedings. OAC was prescribed according to the recommendations of scientific associations. CHADS2 score was obtained for each patient. Results: From February 1, 2000 to July 31, 2003, 796 outpatients fulfilled the inclusion criteria. OAC was prescribed to 564 (71%) patients. After 2.4 ± 1.9 years of follow-up, the embolic event rates (per 100 patient-years) for each stratum of the CHADS2 score for patients with/without OAC were: 1/4.1, p = 0.23 (CHADS2 = 0); 0.6/7.1, p = 0.0018 (CHADS2 = 1); 0.5/5.1, p = 0.0014 (CHADS2 = 2); 2.4/12.5, p = 0.0017 (CHADS2 = 3) and 2.9/20, p = 0.013 (CHADS2 ≧4). The severe bleeding rates for the same CHADS2 score strata were 3/0.8, 0.8/0.7, 1.3/0.7, 0.4/0, and 2.9/5 in patients with/without OAC (n.s.). Conclusion: OAC is effective and safe in daily clinical practice in patients with NVAF and CHADS2 score ≧1.
Comparison of Intravitreal Bevacizumab versus Triamcinolone for the Treatment of Diffuse Diabetic Macular Edema
Authors: Kreutzer Thomas C. , Al Saeidi Rashid , Kook Daniel , Wolf Armin , Ulbig Michael W. , Neubauer Aljoscha S. , Haritoglou Christos
Published: February 2010

Background: Our purpose was to compare the effect of triamcinolone and bevacizumab (Avastin) on the retinal thickness and functional outcome in patients with diabetic macular edema. Methods and Materials: A collective of 32 patients, who had been treated by a single 4.0-mg intravitreal triamcinolone injection (group 1), was matched to 32 patients (‘matched pairs’), who had received 3 injections of 1.25 mg of bevacizumab within 3 months in 4-week intervals (group 2). The outcome variables were changes in best corrected visual acuity (VA) and central retinal thickness 3 months after therapy. Results: Both groups did not differ regarding preoperative VA and central retinal thickness measured by optical coherence tomography. The baseline mean VA was 0.72 ± 0.39 logMAR in group 1 and 0.73 ± 0.39 logMAR in group 2 (p = 0.709). The mean central retinal thickness measured by optical coherence tomography was 548 ± 185 µm in group 1 and 507 ± 192 µm in group 2. While the patients in group 1 experienced a slight increase in VA of on average 0.7 lines following a single triamcinolone injection to a mean of 0.64 ± 0.40 logMAR (p = 0.066) after 3 months, the patients in group 2 showed almost no effect on VA with an average increase of 0.2 lines to a mean VA of 0.72 ± 0.30 logMAR (p = 0.948) following 3 intravitreal injections of bevacizumab. Comparing the effect on VA between both groups no statistically significant difference (p = 0.115) was noted. Concerning decrease in central retinal thickness both therapies were highly effective (p < 0.001 each), again, without statistically significant difference between the groups (p < 0.128). Conclusion: Our data suggest that a single triamcinolone injection may be as effective as a 3 times repeated intravitreal administration of bevacizumab for the treatment of diabetic macular edema. Further prospective trials should be performed.
Analysis of the Impact of Early Surgery on In-Hospital Mortality of Native Valve Endocarditis
Authors: Lalani Tahaniyat , Cabell Christopher H. , Benjamin Daniel K. , Lasca Ovidiu , Naber Christoph , Fowler Vance G. , Corey G. Ralph , Chu Vivian H. , Fenely Michael , Pachirat Orathai , Tan Ru-San , Watkin Richard , Ionac Adina , Moreno Asuncion , Mestres Carlos A. , Casabé José , Chipigina Natalia , Eisen Damon P. , Spelman Denis , Delahaye Francois , Peterson Gail , Olaison Lars , Wang Andrew
Published: February 2010

Background—

The impact of early surgery on mortality in patients with native valve endocarditis (NVE) is unresolved. This study sought to evaluate valve surgery compared with medical therapy for NVE and to identify characteristics of patients who are most likely to benefit from early surgery.

Methods and Results—

Using a prospective, multinational cohort of patients with definite NVE, the effect of early surgery on in-hospital mortality was assessed by propensity-based matching adjustment for survivor bias and by instrumental variable analysis. Patients were stratified by propensity quintile, paravalvular complications, valve perforation, systemic embolization, stroke,
Staphylococcus aureus
infection, and congestive heart failure. Of the 1552 patients with NVE, 720 (46%) underwent early surgery and 832 (54%) were treated with medical therapy. Compared with medical therapy, early surgery was associated with a significant reduction in mortality in the overall cohort (12.1% [87/720] versus 20.7% [172/832]) and after propensity-based matching and adjustment for survivor bias (absolute risk reduction [ARR] −5.9%,
P
<0.001). With a combined instrument, the instrumental-variable–adjusted ARR in mortality associated with early surgery was −11.2% (
P
<0.001). In subgroup analysis, surgery was found to confer a survival benefit compared with medical therapy among patients with a higher propensity for surgery (ARR −10.9% for quintiles 4 and 5,
P
=0.002) and those with paravalvular complications (ARR −17.3%,
P
<0.001), systemic embolization (ARR −12.9%,
P
=0.002),
S aureus
NVE (ARR −20.1%,
P
<0.001), and stroke (ARR −13%,
P
=0.02) but not those with valve perforation or congestive heart failure.

Conclusions—

Early surgery for NVE is associated with an in-hospital mortality benefit compared with medical therapy alone.