bluuebunny/crossref_metadata_2025 huggingface dataset:
The Serpukhovian and Bashkirian (Carboniferous, Namurian and basal Westphalian) faunas of northern England
Authors: Brand P. J.
Published: July 2011

The marine fauna in Serpukhovian and Bashkirian strata (Namurian and basal Westphalian) of northern England shows changes in composition and diversity, both stratigraphically and in geographical distribution across the region. The deposits of distinct marine incursions contain characteristic assemblages of fauna, although few forms, if any, are diagnostic of individual incursions. The results of the study suggest that the depositional area formed an open channel during the marine incursions in which the benthic fauna (that comprises the majority of the recorded forms) is, in general, more prolific in the east. The faunas recorded in both block and basin sedimentary rocks are similar, suggesting that the water depth during deposition was also similar. The difference between block and basin lies in the amount of sediment deposited and the subsidence rate. The Subcrenatum Marine Band shows the most varied faunas in the west.
The cladid crinoid
Rhabdocrinus
Wright from the Namurian of Co. Durham, UK
Authors: Donovan S. K. , Birtle M.
Published: July 2011

Crinoids from the marine succession near the base of the Namurian (Pendleian, Mississippian) of NE England remain poorly known. Robust crinoid pluricolumnals from the Rookhope Shell Beds Limestone, exposed in the banks of the River Tees near Winston, Co. Durham, are identified as
Rhabdocrinus
sp. cf.
R. swaledalensis
Wright. The broad, cyclocyclic pluricolumnals consist of low, heteromorphic N1 columnals that are unlikely to have been derived from any other English Pendleian crinoid. However, the dististele of
R. swaledalensis sensu stricto
remains unknown, hence the specimens from Winston remain in open nomenclature. Attachment was distal with a dendritic radice; large radice scars are common on some specimens. Evidence shows that
Rhabdocrinus
spp. had long stems, certainly hundreds of mm in length in the species from Winston.
Molecular analysis of the luminal- and mucosal-associated intestinal microbiota in diarrhea-predominant irritable bowel syndrome
Authors: Carroll Ian M. , Ringel-Kulka Tamar , Keku Temitope O. , Chang Young-Hyo , Packey Christopher D. , Sartor R. Balfour , Ringel Yehuda
Published: July 2011

Alterations in the intestinal microbiota have been suggested as an etiological factor in the pathogenesis of irritable bowel syndrome (IBS). This study used a molecular fingerprinting technique to compare the composition and biodiversity of the microbiota within fecal and mucosal niches between patients with diarrhea-predominant IBS (D-IBS) and healthy controls. Terminal-restriction fragment (T-RF) length polymorphism (T-RFLP) fingerprinting of the bacterial 16S rRNA gene was used to perform microbial community composition analyses on fecal and mucosal samples from patients with D-IBS ( n = 16) and healthy controls ( n = 21). Molecular fingerprinting of the microbiota from fecal and colonic mucosal samples revealed differences in the contribution of T-RFs to the microbiota between D-IBS patients and healthy controls. Further analysis revealed a significantly lower (1.2-fold) biodiversity of microbes within fecal samples from D-IBS patients than healthy controls ( P = 0.008). No difference in biodiversity in mucosal samples was detected between D-IBS patients and healthy controls. Multivariate analysis of T-RFLP profiles demonstrated distinct microbial communities between luminal and mucosal niches in all samples. Our findings of compositional differences in the luminal- and mucosal-associated microbiota between D-IBS patients and healthy controls and diminished microbial biodiversity in D-IBS fecal samples further support the hypothesis that alterations in the intestinal microbiota may have an etiological role in the pathogenesis of D-IBS and suggest that luminal and mucosal niches need to be investigated.
Glutamine activates peroxisome proliferator-activated receptor-γ in intestinal epithelial cells via 15-S-HETE and 13-OXO-ODE: a novel mechanism
Authors: Ban Kechen , Sprunt Julie M. , Martin Stephanie , Yang Peiying , Kozar Rosemary A.
Published: July 2011

Glutamine possesses gut-protective effects both clinically and in the laboratory. We have shown in a rodent model of mesenteric ischemia-reperfusion that enteral glutamine increased peroxisome proliferator-activated receptor-γ (PPAR-γ) and was associated with a reduction in mucosal injury and inflammation. The mechanism by which glutamine activates PPAR-γ is unknown, and we hypothesized that it was via a ligand-dependent mechanism. Intestinal epithelial cells, IEC-6, were co-transfected with PPAR-γ response element-luciferase promoter/reporter construct. Cells were pretreated with increasing concentrations of glutamine ± GW9662 (a specific antagonist of PPAR-γ) and analyzed for PPAR-γ response element luciferase activity as an indicator of PPAR-γ activation. PPAR-γ nuclear activity was assessed by electrophoretic mobility shift assay. Cell lysates were subjected to tandem mass spectroscopy for measurement of prostaglandin and lipoxygenase metabolites. A time- and concentration-dependent increase in PPAR-γ transcriptional activity, but not mRNA or protein, was demonstrated. Activity was abrogated by the PPAR-γ inhibitor, GW9662, and changes in activity correlated with PPAR-γ nuclear binding. Glutamine, via degradation to glutamate, activated the metabolic by-products of the lipoxygenase and linoleic acid pathways, 15-S-hydroxyeicosatetraenoic acid and dehydrogenated 13-hydroxyoctaolecadienoic acid, known endogenous PPAR-γ ligands in the small bowel. This novel mechanism may explain the gut-protective effects of enteral glutamine.
Tumor necrosis factor receptor 1-dependent depletion of mucus in immature small intestine: a potential role in neonatal necrotizing enterocolitis
Authors: McElroy Steven J. , Prince Lawrence S. , Weitkamp Jörn-Hendrik , Reese Jeff , Slaughter James C. , Polk D. Brent
Published: July 2011

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in premature infants. NEC is believed to occur when intestinal bacteria invade the intestinal epithelial layer, causing subsequent inflammation and tissue necrosis. Mucins are produced and secreted by epithelial goblet cells as a key component of the innate immune system and barrier function of the intestinal tract that help protect against bacterial invasion. To better understand the role of mucins in NEC, we quantified the number of mucus-containing small intestinal goblet cells present in infants with NEC and found they had significantly fewer goblet cells and Paneth cells compared with controls. To test whether inflammation has a developmentally dependent effect on intestinal goblet cells, TNF-α was injected into mice at various stages of intestinal development. TNF-α caused a loss of mucus-containing goblet cells only in immature mice and induced Muc2 and Muc3 mRNA upregulation only in mature ileum. Only minimal changes were seen in apoptosis and in expression of markers of goblet cell differentiation. TNF-α increased small intestinal mucus secretion and goblet cell hypersensitivity to prostaglandin E2 (PGE2), a known mucus secretagogue produced by macrophages. These TNF-α-induced changes in mucus mRNA levels required TNF receptor 2 (TNFR2), whereas TNF-α-induced loss of mucus-positive goblet cells required TNFR1. Our findings of developmentally dependent TNF-α-induced alterations on intestinal mucus may help explain why NEC is predominantly found in premature infants, and TNF-α-induced alterations of the intestinal innate immune system and barrier functions may play a role in the pathogenesis of NEC itself.
Blood vessel remodeling and physical inactivity in humans
Authors: Thijssen Dick H. J. , Green Daniel J. , Hopman Maria T. E.
Published: July 2011

Physical inactivity is associated with an increase in cardiovascular risk that cannot be fully explained by traditional or novel risk factors. Inactivity is also associated with changes in hemodynamic stimuli, which exert direct effects on the vasculature leading to remodeling and a proatherogenic phenotype. In this review, we synthesize and summarize in vivo evidence relating to the impact of local and systemic models of physical inactivity on conduit arteries, resistance vessels, and the microcirculation in humans. Taken together, the literature suggests that a rapid inward structural remodeling of vessels occurs in response to physical inactivity. The magnitude of this response is dependent on the “dose” of inactivity. Moreover, changes in vascular function are found at resistance and microvessel levels in humans. In conduit arteries, a strong interaction between vascular function and structure is present, which results in conflicting data regarding the impact of inactivity on conduit artery function. While much of the cardioprotective effect of exercise is related to the nitric oxide pathway, deconditioning may primarily be associated with activation of vasoconstrictor pathways. The effects of deconditioning on the vasculature are therefore not simply the opposite of those in response to exercise training. Given the importance of sedentary behavior, future studies should provide further insight into the impact of inactivity on the vasculature and other (novel) markers of vascular health. Moreover, studies should examine the role of (hemodynamic) stimuli that underlie the characteristic vascular adaptations during deconditioning. Our review concludes with some suggestions for future research directions.
Regional stiffening with aging in tibialis anterior tendons of mice occurs independent of changes in collagen fibril morphology
Authors: Wood Lauren K. , Arruda Ellen M. , Brooks Susan V.
Published: July 2011

The incidence of tendon degeneration and rupture increases with advancing age. The mechanisms underlying this increased risk remain unknown but may arise because of age-related changes in tendon mechanical properties and structure. Our purpose was to determine the effect of aging on tendon mechanical properties and collagen fibril morphology. Regional mechanical properties and collagen fibril characteristics were determined along the length of tibialis anterior (TA) tendons from adult (8- to 12-mo-old) and old (28- to 30-mo-old) mice. Tangent modulus of all regions along the tendons increased in old age, but the increase was substantially greater in the proximal region adjacent to the muscle than in the rest of the tendon. Overall end-to-end modulus increased with old age at maximum tendon strain (799 ± 157 vs. 1,419 ± 91 MPa) and at physiologically relevant strain (377 ± 137 vs. 798 ± 104 MPa). Despite the dramatic changes in tendon mechanical properties from adulthood to old age, collagen fibril morphology and packing fraction remained relatively constant in all tendon regions examined. Since tendon properties are influenced by their external loading environment, we also examined the effect of aging on TA muscle contractile properties. Maximum isometric force did not differ between the age groups. We conclude that TA tendons stiffen in a region-dependent manner throughout the life span, but the changes in mechanical properties are not accompanied by corresponding changes in collagen fibril morphology or force-generating capacity of the TA muscle.
Effects of different acute hypoxic regimens on tissue oxygen profiles and metabolic outcomes
Authors: Reinke Christian , Bevans-Fonti Shannon , Drager Luciano F. , Shin Mi-Kyung , Polotsky Vsevolod Y.
Published: July 2011

Obstructive sleep apnea (OSA) causes intermittent hypoxia (IH) during sleep. Both obesity and OSA are associated with insulin resistance and systemic inflammation, which may be attributable to tissue hypoxia. We hypothesized that a pattern of hypoxic exposure determines both oxygen profiles in peripheral tissues and systemic metabolic outcomes, and that obesity has a modifying effect. Lean and obese C57BL6 mice were exposed to 12 h of intermittent hypoxia 60 times/h (IH60) [inspired O2 fraction (FiO2) 21–5%, 60/h], IH 12 times/h (FiO2 5% for 15 s, 12/h), sustained hypoxia (SH; FiO2 10%), or normoxia while fasting. Tissue oxygen partial pressure (PtiO2) in liver, skeletal muscle and epididymal fat, plasma leptin, adiponectin, insulin, blood glucose, and adipose tumor necrosis factor-α (TNF-α) were measured. In lean mice, IH60 caused oxygen swings in the liver, whereas fluctuations of PtiO2 were attenuated in muscle and abolished in fat. In obese mice, baseline liver PtiO2 was lower than in lean mice, whereas muscle and fat PtiO2 did not differ. During IH, PtiO2 was similar in obese and lean mice. All hypoxic regimens caused insulin resistance. In lean mice, hypoxia significantly increased leptin, especially during SH (44-fold); IH60, but not SH, induced a 2.5- to 3-fold increase in TNF-α secretion by fat. Obesity was associated with striking increases in leptin and TNF-α, which overwhelmed effects of hypoxia. In conclusion, IH60 led to oxygen fluctuations in liver and muscle and steady hypoxia in fat. IH and SH induced insulin resistance, but inflammation was increased only by IH60 in lean mice. Obesity caused severe inflammation, which was not augmented by acute hypoxic regimens.
Tempol attenuates the exercise pressor reflex independently of neutralizing reactive oxygen species in femoral artery ligated rats
Authors: McCord Jennifer L. , Tsuchimochi Hirotsugu , Yamauchi Katsuya , Leal Anna , Kaufman Marc P.
Published: July 2011

In decerebrate rats, we reported previously that the exercise pressor reflex arising from a limb whose femoral artery was occluded for 72 h before the experiment was significantly higher than the exercise pressor reflex arising from a contralateral freely perfused limb. These findings prompted us to examine whether reactive oxygen species contributed to the augmented pressor reflex in rats with femoral artery occlusion. We found that the pressor reflex arising from the limb whose femoral artery was occluded for 72 h before the experiment (31 ± 5 mmHg) was attenuated by tempol (10 mg), a superoxide dismutase (SOD) mimetic (18 ± 5 mmHg, n = 9, P < 0.05), that was injected into the arterial supply of the hindlimb. In contrast, the pressor reflex arising from a freely perfused hindlimb (20 ± 3 mmHg) was not attenuated by tempol (17 ± 4 mmHg, n = 10, P = 0.49). Nevertheless, we found no difference in the increase in 8-isoprostaglandin F2α levels, an index of reactive oxygen species, in response to contraction between freely perfused (3.76 ± 0.82 pg/ml, n = 19) and 72-h occluded (3.51 ± 0.92 pg/ml, n = 22, P = 0.90) hindlimbs. Moreover, tempol did not reduce the 8-isoprostaglandin F2α levels during contraction in either group ( P > 0.30). A second SOD mimetic, tiron (200 mg/kg), had no effect on the exercise pressor reflex in either the rats with freely perfused hindlimbs or in those with occluded femoral arteries. These findings suggest that tempol attenuated the exercise pressor reflex in the femoral artery-occluded hindlimb by a mechanism that was independent of its ability to scavenge reactive oxygen species.
Effect of experimental muscle pain on maximal voluntary activation of human biceps brachii muscle
Authors: Khan Serajul I. , McNeil Chris J. , Gandevia Simon C. , Taylor Janet L.
Published: July 2011

Muscle pain has widespread effects on motor performance, but the effect of pain on voluntary activation, which is the level of neural drive to contracting muscle, is not known. To determine whether induced muscle pain reduces voluntary activation during maximal voluntary contractions, voluntary activation of elbow flexors was assessed with both motor-point stimulation and transcranial magnetic stimulation over the motor cortex. In addition, we performed a psychophysical experiment to investigate the effect of induced muscle pain across a wide range of submaximal efforts (5–75% maximum). In all studies, elbow flexion torque was recorded before, during, and after experimental muscle pain by injection of 1 ml of 5% hypertonic saline into biceps. Injection of hypertonic saline evoked deep pain in the muscle (pain rating ∼5 on a scale from 0 to 10). Experimental muscle pain caused a small (∼5%) but significant reduction of maximal voluntary torque in the motor-point and motor cortical studies ( P < 0.001 and P = 0.045, respectively; n = 7). By contrast, experimental muscle pain had no significant effect on voluntary activation when assessed with motor-point and motor cortical stimulation although voluntary activation tested with motor-point stimulation was reduced by ∼2% in contractions after pain had resolved ( P = 0.003). Furthermore, induced muscle pain had no significant effect on torque output during submaximal efforts ( P > 0.05; n = 6), which suggests that muscle pain did not alter the relationship between the sense of effort and production of voluntary torque. Hence, the present study suggests that transient experimental muscle pain in biceps brachii has a limited effect on central motor pathways.
Chronic oscillatory strain induces MLCK associated rapid recovery from acute stretch in airway smooth muscle cells
Authors: Connolly Sarah C. , Smith Paul G. , Fairbank Nigel J. , Lall Carolyn A. , Cole Darren J. , MacKinnon James D. , Maksym Geoffrey N.
Published: July 2011

A deep inspiration (DI) temporarily relaxes agonist-constricted airways in normal subjects, but in asthma airways are refractory and may rapidly renarrow, possibly due to changes in the structure and function of airway smooth muscle (ASM). Chronic largely uniaxial cyclic strain of ASM cells in culture causes several structural and functional changes in ASM similar to that in asthma, including increases in contractility, MLCK content, shortening velocity, and shortening capacity. However, changes in recovery from acute stretch similar to a DI have not been measured. We have therefore measured the response and recovery to large stretches of cells modified by chronic stretching and investigated the role of MLCK. Chronic, 10% uniaxial cyclic stretch, with or without a strain gradient, was administered for up to 11 days to cultured cells grown on Silastic membranes. Single cells were then removed from the membrane and subjected to 1 Hz oscillatory stretches up to 10% of the in situ cell length. These oscillations reduced stiffness by 66% in all groups ( P < 0.05). Chronically strained cells recovered stiffness three times more rapidly than unstrained cells, while the strain gradient had no effect. The stiffness recovery in unstrained cells was completely inhibited by the MLCK inhibitor ML-7, but recovery in strained cells exhibiting increased MLCK was slightly inhibited. These data suggest that chronic strain leads to enhanced recovery from acute stretch, which may be attributable to the strain-induced increases in MLCK. This may also explain in part the more rapid renarrowing of activated airways following DI in asthma.
CaMKII in the Cardiovascular System: Sensing Redox States
Authors: Erickson Jeffrey R. , He B. Julie , Grumbach Isabella M. , Anderson Mark E.
Published: July 2011

The multifunctional Ca2+- and calmodulin-dependent protein kinase II (CaMKII) is now recognized to play a central role in pathological events in the cardiovascular system. CaMKII has diverse downstream targets that promote vascular disease, heart failure, and arrhythmias, so improved understanding of CaMKII signaling has the potential to lead to new therapies for cardiovascular disease. CaMKII is a multimeric serine-threonine kinase that is initially activated by binding calcified calmodulin (Ca2+/CaM). Under conditions of sustained exposure to elevated Ca2+/CaM, CaMKII transitions into a Ca2+/CaM-autonomous enzyme by two distinct but parallel processes. Autophosphorylation of threonine-287 in the CaMKII regulatory domain “traps” CaMKII into an open configuration even after Ca2+/CaM unbinding. More recently, our group identified a pair of methionines (281/282) in the CaMKII regulatory domain that undergo a partially reversible oxidation which, like autophosphorylation, prevents CaMKII from inactivating after Ca2+/CaM unbinding. Here we review roles of CaMKII in cardiovascular disease with an eye to understanding how CaMKII may act as a transduction signal to connect pro-oxidant conditions into specific downstream pathological effects that are relevant to rare and common forms of cardiovascular disease.
Myocardial AKT: The Omnipresent Nexus
Authors: Sussman Mark A. , Völkers Mirko , Fischer Kimberlee , Bailey Brandi , Cottage Christopher T. , Din Shabana , Gude Natalie , Avitabile Daniele , Alvarez Roberto , Sundararaman Balaji , Quijada Pearl , Mason Matt , Konstandin Mathias H. , Malhowski Amy , Cheng Zhaokang , Khan Mohsin , McGregor Michael
Published: July 2011

One of the greatest examples of integrated signal transduction is revealed by examination of effects mediated by AKT kinase in myocardial biology. Positioned at the intersection of multiple afferent and efferent signals, AKT exemplifies a molecular sensing node that coordinates dynamic responses of the cell in literally every aspect of biological responses. The balanced and nuanced nature of homeostatic signaling is particularly essential within the myocardial context, where regulation of survival, energy production, contractility, and response to pathological stress all flow through the nexus of AKT activation or repression. Equally important, the loss of regulated AKT activity is primarily the cause or consequence of pathological conditions leading to remodeling of the heart and eventual decompensation. This review presents an overview compendium of the complex world of myocardial AKT biology gleaned from more than a decade of research. Summarization of the widespread influence that AKT exerts upon myocardial responses leaves no doubt that the participation of AKT in molecular signaling will need to be reckoned with as a seemingly omnipresent regulator of myocardial molecular biological responses.
microRNA-Associated Progression Pathways and Potential Therapeutic Targets Identified by Integrated mRNA and microRNA Expression Profiling in Breast Cancer
Authors: Buffa Francesca M. , Camps Carme , Winchester Laura , Snell Cameron E. , Gee Harriet E. , Sheldon Helen , Taylor Marian , Harris Adrian L. , Ragoussis Jiannis
Published: July 2011

microRNA expression profiling plays an emerging role in cancer classification and identification of therapeutic strategies. In this study, we have evaluated the benefits of a joint microRNA–mRNA analysis in breast cancer.

Matched mRNA and microRNA global expression profiling was conducted in a well-annotated cohort of 207 cases with complete 10-year follow-up. Penalized Cox regression including microRNA expression, mRNA expression, and clinical covariates was used to identify microRNAs associated with distant relapse-free survival (DRFS) that provide independent prognostic information, and are not simply surrogates of previously identified prognostic covariates. Penalized regression was chosen to prevent overfitting. Furthermore, microRNA–mRNA relationships were explored by global expression analysis, and exploited to validate results in several published cohorts (n = 592 with DRFS, n = 1,050 with recurrence-free survival).

Four microRNAs were independently associated with DRFS in estrogen receptor (ER)-positive (3 novel and 1 known; miR-128a) and 6 in ER-negative (5 novel and 1 known; miR-210) cases. Of the latter, miR-342, -27b, and -150 were prognostic also in triple receptor-negative tumors. Coordinated expression of predicted target genes and prognostic microRNAs strengthened these results, most significantly for miR-210, -128a, and -27b, whose targets were prognostic in meta-analysis of several cohorts. In addition, miR-210 and -128a showed coordinated expression with their cognate pri-microRNAs, which were themselves prognostic in independent cohorts.

Our integrated microRNA–mRNA global profiling approach has identified microRNAs independently associated with prognosis in breast cancer. Furthermore, it has validated known and predicted microRNA–target interactions, and elucidated their association with key pathways that could represent novel therapeutic targets. Cancer Res; 71(17); 5635–45. ©2011 AACR.
Phase II Trials Powered to Detect Tumor Subtypes
Authors: Roberts John D. , Ramakrishnan Viswanathan
Published: July 2011

Classical phase II trial designs, including “adaptive” designs, require the prospective characterization of tumors. We propose a 2-stage phase II design that allows for characterization of tumors and selection of a tumor subtype of interest at the conclusion of stage 1. The stage 2 objective is either a classical estimate of the response rate for either the tumor or a subtype, or a formal test of the hypothesis that the response rate for a subtype is greater than the overall response rate. Considering likely scenarios, stage 1 sample sizes approximately range from 20 to 100 with a usual size of 50. This compares with typical classical stage 1 sample sizes of 12 to 30. Total sample sizes range from sizes identical to classical designs (tens to scores) to large sizes typical of phase III trials in metastatic disease (hundreds). Our design is more efficient than previous adaptive designs because it allows for the selection of a tumor subtype of interest on the basis of results from stage 1. It complements classical phase II and phase III designs in which investigators compare different treatments in similar patients and tumors by positioning a treatment as fixed (control) and using tumor subtype as the variable of interest. Clin Cancer Res; 17(17); 5538–45. ©2011 AACR.
Antitumor Activity of YM155, a Selective Small-Molecule Survivin Suppressant, Alone and in Combination with Docetaxel in Human Malignant Melanoma Models
Authors: Yamanaka Kentaro , Nakahara Takahito , Yamauchi Tomohiro , Kita Aya , Takeuchi Masahiro , Kiyonaga Fumiko , Kaneko Naoki , Sasamata Masao
Published: July 2011

Purpose: Aggressive cell growth and chemoresistance are notorious obstacles in melanoma therapy. Accumulating evidence suggests that survivin is preferentially expressed in cancer cells and plays a crucial role in cell division and apoptosis dysfunction. Here, we evaluated the therapeutic potential of YM155, a selective survivin suppressant, alone and in combination with docetaxel using human melanoma models.

Experimental Design: A375 and SK-MEL-5 human malignant melanoma cells were treated with siRNA, YM155, and/or docetaxel, and cell viability, mRNA and protein expression levels, cell-cycle distribution, and immunohistochemical staining were then evaluated. Furthermore, the efficacy of YM155 combined with docetaxel was further examined in established xenograft models.

Results: Survivin suppression was sufficient to induce spontaneous apoptosis of melanoma cells. YM155 showed nanomolar antiproliferative effects and induced tumor regression in established melanoma xenograft models. Docetaxel showed antitumor activity against melanoma cells, although it also induced survivin upregulation and G2/M mitotic arrest; however, cotreatment with YM155 decreased survivin expression below basal levels. Combination treatment of YM155 and docetaxel induced a greater rate of apoptosis than the sum of the single-treatment rates and promoted tumor regression without enhanced body weight loss in the melanoma xenograft models.

Conclusions: Survivin is responsible for the inherent low levels of spontaneous apoptosis in melanoma cells. The concomitant combination of YM155 with docetaxel diminished the accumulation of survivin in G2/M mitotic arrest, and induced more intense apoptosis compared with each single treatment. YM155 in combination with docetaxel is well tolerated and shows greater efficacy than either agent alone in mouse xenograft models. Clin Cancer Res; 17(16); 5423–31. ©2011 AACR.
Membranous Expression of Ectodomain Isoforms of the Epidermal Growth Factor Receptor Predicts Outcome after Chemoradiotherapy of Lymph Node–Negative Cervical Cancer
Authors: Halle Cathinka , Lando Malin , Svendsrud Debbie Hege , Clancy Trevor , Holden Marit , Sundfør Kolbein , Kristensen Gunnar B. , Holm Ruth , Lyng Heidi
Published: July 2011

Purpose: We compared the prognostic significance of ectodomain isoforms of the epidermal growth factor receptor (EGFR), which lack the tyrosine kinase (TK) domain, with that of the full-length receptor and its autophosphorylation status in cervical cancers treated with conventional chemoradiotherapy.

Experimental Design: Expression of EGFR isoforms was assessed by immunohistochemistry in a prospectively collected cohort of 178 patients with squamous cell cervical carcinoma, and their detection was confirmed with Western blotting and reverse transcriptase PCR. A proximity ligation immunohistochemistry assay was used to assess EGFR-specific autophosphorylation. Pathways associated with the expression of ectodomain isoforms were studied by gene expression analysis with Illumina beadarrays in 110 patients and validated in an independent cohort of 41 patients.

Results: Membranous expression of ectodomain isoforms alone, without the coexpression of the full-length receptor, showed correlations to poor clinical outcome that were highly significant for lymph node–negative patients (locoregional control, P = 0.0002; progression-free survival, P < 0.0001; disease-specific survival, P = 0.005 in the log-rank test) and independent of clinical variables. The ectodomain isoforms were primarily 60-kD products of alternative EGFR transcripts. Their membranous expression correlated with transcriptional regulation of oncogenic pathways including activation of MYC and MAX, which was significantly associated with poor outcome. This aggressive phenotype of ectodomain EGFR expressing tumors was confirmed in the independent cohort. Neither total nor full-length EGFR protein level, or autophosphorylation status, showed prognostic significance.

Conclusion: Membranous expression of ectodomain EGFR isoforms, and not TK activation, predicts poor outcome after chemoradiotherapy for patients with lymph node–negative cervical cancer. Clin Cancer Res; 17(16); 5501–12. ©2011 AACR.
Long-Range Epigenetic Silencing Associates with Deregulation of Ikaros Targets in Colorectal Cancer Cells
Authors: Javierre Biola M. , Rodriguez-Ubreva Javier , Al-Shahrour Fatima , Corominas Marina , Graña Osvaldo , Ciudad Laura , Agirre Xabier , Pisano David G. , Valencia Alfonso , Roman-Gomez Jose , Calasanz Maria Jose , Prosper Felipe , Esteller Manel , Gonzalez-Sarmiento Rogelio , Ballestar Esteban
Published: July 2011

Transcription factors are common targets of epigenetic inactivation in human cancer. Promoter hypermethylation and subsequent silencing of transcription factors can lead to further deregulation of their targets. In this study, we explored the potential epigenetic deregulation in cancer of Ikaros family genes, which code for essential transcription factors in cell differentiation and exhibit genetic defects in hematologic neoplasias. Unexpectedly, our analysis revealed that Ikaros undergoes very specific promoter hypermethylation in colorectal cancer, including in all the cell lines studied and around 64% of primary colorectal adenocarcinomas, with increasing proportions in advanced Duke's stages. Ikaros hypermethylation occurred in the context of a novel long-range epigenetic silencing (LRES) region. Reintroduction of Ikaros in colorectal cancer cells, ChIP-chip analysis, and validation in primary samples led us to identify a number of direct targets that are possibly related with colorectal cancer progression. Our results not only provide the first evidence that LRES can have functional specific effects in cancer but also identify several deregulated Ikaros targets that may contribute to progression in colorectal adenocarcinoma. Mol Cancer Res; 9(8); 1139–51. ©2011 AACR.
Acute Kidney Injury Caused by Bothrops Snake Venom
Authors: Rodrigues Sgrignolli Lívia , Florido Mendes Glória Elisa , Carlos Carla Patricia , Burdmann Emmanuel A.
Published: July 2011

Medically important venomous snakes in Latin America belong to the genus Bothrops, Crotalus, Lachesis and Micrurus. The Bothrops genus is responsible for the majority of accidents. The WHO globally estimates 2,500,000 poisonous snakebites and 125,000 deaths annually. In its last report in 2001, the Brazilian Ministry of Health accounted 359 deaths due to snakebites, of which the Bothrops genus was responsible for 185. Snake venoms cause local and systemic damage, including acute kidney injury, which is the most important cause of death among patients surviving the early effects of envenoming by the Crotalus and Bothrops genuses. Venom-induced acute kidney injury is a frequent complication of Bothrops snakebite, carrying relevant morbidity and mortality.
Angiotensin-Converting Enzyme Gene Polymorphism and N-Acetyl-β-D-Glucosaminidase Excretion in Endemic Nephropathy
Authors: Pećin Ivan , Čvorišćec Dubravka , Miletić-Medved Marica , Dika Živka , Cvitković Ante , Vitale Ksenija , Leko Ninoslav , Novaković Dinko , Sertić Jadranka , Kos Jelena , Jelaković Bojan
Published: July 2011

Background: Tubular proteinuria and enzymuria are hallmarks of endemic nephropathy (EN). The role of I/D angiotensin convertase (ACE) gene polymorphism has not yet been elucidated in this peculiar chronic tubulointerstitial nephritis, and our aim was to investigate the role of this polymorphism in EN focusing on the urinary N-acetyl-β-D-glucosaminidase (NAG) excretion, a biomarker of proximal tubular damage. Methods:ACE genotype and allele frequencies were determined in 229 farmers (147 women and 82 men) from an endemic Croatian village. The farmers were stratified according to the WHO criteria into the following subgroups: those ‘at risk’ for EN (n = 37), ‘suspected of having EN’ (n = 57), and ‘others’ (n = 135). Results: There were 74 (32.3%) subjects homozygous for the D allele, 99 (43.2%) heterozygous (ID genotype) and 56 (24.4%) homozygous for the I allele. No differences in allele frequency were found between the established WHO subgroups (p > 0.05). In the whole group, DD subjects had significantly higher values of diastolic blood pressure (p = 0.003) and urinary NAG than subjects with ID and II genotype (5.5 ± 1.2 vs. 4.0 ± 3.0 vs. 3.8 ± 4.2, respectively; p = 0.023). The highest values of serum creatinine (p = 0.02), proteinuria (p = 0.03) and urinary NAG (6.0 ± 3.7 vs. 3.7 ± 2.1 vs. 3.0 ± 1.6, respectively; p = 0.008) were observed in those suspected of having EN group with the DD genotype. Conclusion:ACE gene polymorphism is not a risk factor for EN. However, it might influence the clinical course of EN, and increased excretion of NAG might be a prognostic marker of this chronic tubulointerstitial nephritis.
Long-Term Effects of Rituximab Added to Cyclophosphamide in Refractory Patients with Vasculitis
Authors: Roccatello Dario , Sciascia Savino , Rossi Daniela , Alpa Mirella , Naretto Carla , Russo Alessandra , Menegatti Elisa , Baldovino Simone
Published: July 2011

Background: Current therapies have changed systemic vasculitis from a disease with a high rate of mortality to a chronic curable condition. A limited percentage of patients either remains refractory to conventional treatment or experiences dose-limiting side effects. Methods: 11 patients (4 affected by idiopathic systemic microscopic polyangiitis, 5 by Wegener’s granulomatosis, and 2 by Churg-Strauss syndrome) intolerant or refractory to conventional therapies including cyclophosphamide were enrolled. All patients received rituximab as a rescue therapy and were followed for 30–54 months. Following rituximab administration, immunosuppressive drugs were rapidly tapered and no immunosuppressive maintenance therapy was given. Results: Significant decreases in levels of serum creatinine, proteinuria, erythrocyte sedimentation rate, C-reactive protein, and ANCA titers were observed during the follow-up (at least 30 months after rituximab administration). Arthralgia and weakness rapidly disappeared in all patients. Out of 7 patients, 5 reported a decrease in the degree of paresthesia and in the electrophysiologic parameters. Six months after rituximab administration the mean dose of prednisone was 5.5 mg/day. Conclusion: In this sample of patients with systemic vasculitis who were refractory or intolerant to more conventional treatment, rituximab proved to be safe and effective in a long-term follow-up, and showed steroid- and immunosuppressive-sparing effects allowing the persistence of long-lasting remissions without maintenance therapy.
Rho-Associated Kinase Activity, Endothelial Function, and Cardiovascular Risk Factors
Authors: Soga Junko , Noma Kensuke , Hata Takaki , Hidaka Takayuki , Fujii Yuichi , Idei Naomi , Fujimura Noritaka , Mikami Shinsuke , Maruhashi Tatsuya , Kihara Yasuki , Chayama Kazuaki , Kato Hitoshi , Liao James K. , Higashi Yukihito
Published: July 2011

Objective—

Cardiovascular diseases are associated with chronic activation of Rho-associated kinases (ROCKs) and endothelial dysfunction. Both increased ROCK activity and endothelial dysfunction are thought to be closely associated with conventional cardiovascular risk factors. The purpose of this study was to determine the relationships between ROCK activity, endothelial function, and cardiovascular risk factors.

Methods and Results—

We evaluated ROCK activity in peripheral leukocytes by Western blot analysis and flow-mediated vasodilation by ultrasonography in 242 men who had no cardiovascular or cerebrovascular diseases (mean age, 40±10 years; range, 20 to 73 years). ROCK activity was defined as the ratio of phospho myosin-binding subunit on myosin light chain phosphatase to total myosin-binding subunit. Univariate regression analysis revealed that leukocyte ROCK activity significantly correlated with body mass index (
r
=0.29,
P
=0.003); systolic blood pressure (
r
=0.25,
P
=0.01); low-density lipoprotein cholesterol level (
r
=0.21,
P
=0.04); and Framingham risk factor score, a cumulative cardiovascular risk index for heart attack (
r
=0.31,
P
<0.001), and that flow-mediated vasodilation significantly correlated with age (
r
=−0.23,
P
=0.02), body mass index (
r
=0.19,
P
=0.05), systolic blood pressure (
r
=−0.22,
P
=0.03), total cholesterol level (
r
=−0.21,
P
=0.04), low-density lipoprotein cholesterol level (
r
=−0.22,
P
=0.04), glucose level (
r
=−0.20,
P
=0.04), and Framingham risk factor score (
r
=−0.37,
P
<0.001). There was a significant correlation between leukocyte ROCK activity and flow-mediated vasodilation (
r
=−0.41,
P
<0.001). Multivariate analysis revealed that flow-mediated vasodilation was an independent predictor of leukocyte ROCK activity.

Conclusion—

These findings suggest that cumulative cardiovascular risk may enhance ROCK activity and endothelial dysfunction, leading to progression of cardiovascular diseases and outcomes.
Strain-Rate Imaging Predicts the Attenuation of Left Ventricular Remodeling Induced by Ischemic Postconditioning After Myocardial Infarction in Mice
Authors: Thibault Hélène , Gomez Ludovic , Bergerot Cyrille , Augeul Lionel , Scherrer-Crosbie Marielle , Ovize Michel , Derumeaux Geneviève
Published: July 2011

Background—

Systolic strain rate (SR) has been shown to correlate with the transmural extent of myocardial infarction (MI). Ischemic postconditioning (PC) decreases MI size. We aimed to determine whether SR may predict the reduction of left ventricular (LV) remodeling induced by PC in a murine model of ischemia-reperfusion.

Methods and Results—

C57BL6 mice underwent 60 minutes of left coronary artery occlusion followed by reperfusion. PC consisted of 3 cycles of 1 minute of reperfusion and 1 minute of ischemia performed immediately after reperfusion. After 24 hours of reperfusion, a first subset of mice was euthanized for determination of infarct size. An additional subset of mice underwent 3 months of reperfusion. Echocardiography and SR were serially assessed at baseline, 3 days, and 1, 2, 3 months after reperfusion. PC decreased the infarct size and increased SR values within infarcted segments as soon as 24 hours after reperfusion as compared with controls (14±1 versus 6±1 s
−1
,
P
<0.001). Systolic SR was correlated with MI size assessed by the area of infarction/area at risk (
r
=−0.88,
P
<0.001). At 3 months, PC improved LV ejection fraction (55±4 versus 45±3%;
P
<0.05) and decreased LV dimensions as compared with controls. Strain rate at day 3 correlated with LV ejection fraction (0.75;
P
<0.001), end-systolic (
r
=−0.75;
P
=0.001), and end-diastolic volumes (
r
=−0.70;
P
<0.001) at month 3.

Conclusions—

In this murine model of MI, SR accurately assessed the reduction in MI size induced by PC early after reperfusion and the subsequent reduction of LV remodeling.
Fasting-Induced Myocardial Lipid Accumulation in Long-Chain Acyl-CoA Dehydrogenase Knockout Mice Is Accompanied by Impaired Left Ventricular Function
Authors: Bakermans Adrianus J. , Geraedts Tom R. , van Weeghel Michel , Denis Simone , João Ferraz Maria , Aerts Johannes M.F.G. , Aten Jan , Nicolay Klaas , Houten Sander M. , Prompers Jeanine J.
Published: July 2011

Background—

Lipotoxicity may be a key contributor to the pathogenesis of cardiac abnormalities in mitochondrial long-chain fatty acid β-oxidation (FAO) disorders. Few data are available on myocardial lipid levels and cardiac performance in FAO deficiencies. The purpose of this animal study is to assess fasting-induced changes in cardiac morphology, function, and triglyceride (TG) storage as a consequence of FAO deficiency in a noninvasive fashion.

Methods and Results—

MRI and proton magnetic resonance spectroscopy (
1
H-MRS) were applied in vivo in long-chain acyl-CoA dehydrogenase (LCAD) knockout (KO) mice and wild-type (WT) mice (n=8 per genotype). Fasting was used to increase the heart's dependency on FAO for maintenance of energy homeostasis. In vivo data were complemented with ex vivo measurements of myocardial lipids. Left ventricular (LV) mass was higher in LCAD KO mice compared with WT mice (
P
<0.05), indicating LV myocardial hypertrophy. Myocardial TG content was higher in LCAD KO mice at baseline (
P
<0.001) and further increased in fasted LCAD KO mice (
P
<0.05). Concomitantly, LV ejection fraction (
P
<0.01) and diastolic filling rate (
P
<0.01) decreased after fasting, whereas these functional parameters did not change in fasted WT mice. Myocardial ceramide content was higher in fasted LCAD KO mice compared with fasted WT mice (
P
<0.05).

Conclusions—

Using a noninvasive approach, this study reveals accumulation of myocardial TG in LCAD KO mice. Toxicity of accumulating lipid metabolites such as ceramides may be responsible for the fasting-induced impairment of cardiac function observed in the LCAD KO mouse.
Evaluation of the Left Atrial Appendage With Real-Time 3-Dimensional Transesophageal Echocardiography
Authors: Nucifora Gaetano , Faletra Francesco F. , Regoli François , Pasotti Elena , Pedrazzini Giovanni , Moccetti Tiziano , Auricchio Angelo
Published: July 2011

Background—

Precise knowledge of left atrial appendage (LAA) orifice size is crucial for correct sizing of LAA closure devices. The aim of the present study was to determine the performance of real-time 3D transesophageal echocardiography (RT3DTEE) for LAA orifice size assessment, compared with 2D transesophageal echocardiography (2DTEE), and to investigate the impact of atrial fibrillation (AF) on LAA orifice size.

Methods and Results—

One hundred thirty-seven patients (38 control subjects, 31 with paroxysmal AF, 38 with persistent AF and 30 with permanent AF) underwent 2DTEE and RT3DTEE. Both techniques were used to measure LAA orifice area. Clinically-indicated 64-slice computed tomography (CT) was used as reference technique in 46 patients. Two-dimensional TEE underestimated LAA orifice area, compared with RT3DTEE (1.99±0.94 cm
2
versus 3.05±1.27 cm
2
;
P
<0.001). RT3DTEE showed higher correlation with CT for the assessment of LAA orifice area, compared with 2DTEE (
r
=0.92; 95% confidence interval, 0.85 to 0.95, versus
r
=0.72; 95% confidence interval, 0.54 to 0.83, respectively). At Bland–Altman analysis, RT3DTEE and 2DTEE underestimated LAA orifice area, compared with CT. However, RT3DTEE showed smaller bias (0.07 cm
2
versus 0.72 cm
2
) and narrower limits of agreement (−0.71 to 0.85 cm
2
versus −0.58 to 2.02 cm
2
) with CT, compared with 2DTEE. Among AF patients, a progressive increase in RT3DTEE-derived LAA orifice area was observed with increasing frequency of AF (
P
<0.001). At multivariate analysis, AF and left atrial volume index (
P
<0.001 for both) were independently associated with RT3DTEE-derived LAA orifice area.

Conclusions—

RT3DTEE is more accurate than 2DTEE for the assessment of LAA orifice size. A progressive increase in LAA orifice area is observed with increasing frequency of AF.
Network for Activation of Human Endothelial Cells by Oxidized Phospholipids
Authors: Romanoski Casey E. , Che Nam , Yin Fen , Mai Nguyen , Pouldar Delila , Civelek Mete , Pan Calvin , Lee Sangderk , Vakili Ladan , Yang Wen-Pin , Kayne Paul , Mungrue Imran N. , Araujo Jesus A. , Berliner Judith A. , Lusis Aldons J.
Published: July 2011

Rationale:

Oxidized palmitoyl arachidonyl phosphatidylcholine (Ox-PAPC) accumulates in atherosclerotic lesions, is proatherogenic, and influences the expression of more than 1000 genes in endothelial cells.

Objective:

To elucidate the major pathways involved in Ox-PAPC action, we conducted a systems analysis of endothelial cell gene expression after exposure to Ox-PAPC.

Methods and Results:

We used the variable responses of primary endothelial cells from 149 individuals exposed to Ox-PAPC to construct a network that consisted of 11 groups of genes, or modules. Modules were enriched for a broad range of Gene Ontology pathways, some of which have not been identified previously as major Ox-PAPC targets. Further validating our method of network construction, modules were consistent with relationships established by cell biology studies of Ox-PAPC effects on endothelial cells. This network provides novel hypotheses about molecular interactions, as well as candidate molecular regulators of inflammation and atherosclerosis. We validated several hypotheses based on network connections and genomic association. Our network analysis predicted that the hub gene CHAC1 (cation transport regulator homolog 1) was regulated by the ATF4 (activating transcription factor 4) arm of the unfolded protein response pathway, and here we showed that ATF4 directly activates an element in the CHAC1 promoter. We showed that variation in basal levels of heme oxygenase 1 (HMOX1) contribute to the response to Ox-PAPC, consistent with its position as a hub in our network. We also identified G-protein–coupled receptor 39 (GPR39) as a regulator of HMOX1 levels and showed that it modulates the promoter activity of HMOX1. We further showed that OKL38/OSGN1 (oxidative stress–induced growth inhibitor), the hub gene in the blue module, is a key regulator of both inflammatory and antiinflammatory molecules.

Conclusions:

Our systems genetics approach has provided a broad view of the pathways involved in the response of endothelial cells to Ox-PAPC and also identified novel regulatory mechanisms.