bluuebunny/crossref_metadata_2025 huggingface dataset:
Dose-dependent responses of myofibrillar protein synthesis with beef ingestion are enhanced with resistance exercise in middle-aged men
Authors: Robinson Meghann J. , Burd Nicholas A. , Breen Leigh , Rerecich Tracy , Yang Yifan , Hector Amy J. , Baker Steven K. , Phillips Stuart M.
Published: November 2012

Aging impairs the sensitivity of skeletal muscle to anabolic stimuli, such as amino acids and resistance exercise. Beef is a nutrient-rich source of dietary protein capable of stimulating muscle protein synthesis (MPS) rates in older men at rest. To date, the dose–response of myofibrillar protein synthesis to graded ingestion of protein-rich foods, such as beef, has not been determined. We aimed to determine the dose–response of MPS with and without resistance exercise to graded doses of beef ingestion. Thirty-five middle-aged men (59 ± 2 years) ingested 0 g, 57 g (2 oz; 12 g protein), 113 g (4 oz; 24 g protein), or 170 g (6 oz; 36 g protein) of (15% fat) ground beef (n = 7 per group). Subjects performed a bout of unilateral resistance exercise to allow measurement of the fed state and the fed plus resistance exercise state within each dose. A primed constant infusion of l-[1-13C]leucine was initiated to measure leucine oxidation and of l-[ring-13C6]phenylalanine was initiated to measure myofibrillar MPS. Myofibrillar MPS was increased with ingestion of 170 g of beef to a greater extent than all other doses at rest and after resistance exercise. There was more leucine oxidation with ingestion of 113 g of beef than with 0 g and 57 g, and it increased further after ingestion of 170 g of beef (all p < 0.05). Ingestion of 170 g of beef protein is required to stimulate a rise in myofibrillar MPS over and above that seen with lower doses. An isolated bout of resistance exercise was potent in stimulating myofibrillar MPS, and acted additively with feeding.
Caffeine ingestion impairs insulin sensitivity in a dose-dependent manner in both men and women
Authors: Beaudoin Marie-Soleil , Allen Brian , Mazzetti Gillian , Sullivan Peter J. , Graham Terry E.
Published: November 2012

The effects of alkaloid caffeine on insulin sensitivity have been investigated primarily in men, and with a single caffeine dose most commonly of 5–6 mg·kg−1 of body weight (BW). It is unknown if the effects of caffeine on glucose homeostasis are sex-specific and (or) dose-dependent. This study examined whether caffeine ingestion would disrupt glucose homeostasis in a dose-dependent or threshold manner. It also examined whether sex-specific responses to caffeine exist. It was hypothesized that women would have an exaggerated response to caffeine, and that caffeine would only impair glucose metabolism once a threshold was reached. Twenty-four healthy volunteers (12 males, 12 females) participated in 4 trials, in a crossover, randomized, and double-blind fashion. They ingested caffeine (1, 3, or 5 mg·kg−1 of BW) or placebo followed, 1 h later, by a 2-h oral glucose tolerance test. Glucose, insulin, C-peptide area under the curve (AUC), and insulin sensitivity index data were fitted to a segmented linear model to determine dose–responses. There were no differences between sexes for any endpoints. Regression slopes were significantly different from zero (p < 0.05) for glucose, insulin, and C-peptide AUCs, with thresholds being no different from zero. Increasing caffeine consumption by 1 mg·kg−1 of BW increased insulin and C-peptide AUCs by 5.8% and 8.7%, respectively. Despite this exaggerated insulin response, glucose AUC increased by 11.2 mmol per 120 min·L–1 for each mg·kg−1 BW consumed. These results showed that caffeine ingestion disrupted insulin sensitivity in a dose-dependent fashion beginning at very low doses (0–1 mg·kg−1 BW) in both healthy men and women.
Bone marrow cell transplantation is associated with fibrogenic cells apoptosis during hepatic regeneration in cholestatic rats
Authors: Nunes de Carvalho Simone , da Cunha Lira Dalvaci , Costa Cortez Erika Afonso , de Andrade Daniela Caldas , Thole Alessandra Alves , Stumbo Ana Carolina , de Carvalho Lais
Published: November 2012

Liver fibrosis is accompanied by hepatocyte death and proliferation of α-SMA+ fibrogenic cells (activated hepatic stellate cells and myofibroblasts), which synthesize extracellular matrix components that contribute to disorganization of the hepatic parenchyma and loss of liver function. Therefore, apoptosis of these fibrogenic cells is important to hepatic regeneration. This study aimed to analyze the effect of cell therapy using bone marrow mononuclear cell (BMMNC) transplantation on α-SMA expression and on apoptosis of hepatic cells during liver fibrosis induced by bile duct ligation (BDL). Livers were collected from normal rats, fibrotic rats after 14 and 21 days of BDL, and rats that received BMMNC at 14 days of BDL and were analyzed after 7 days. Apoptosis in fibrogenic cells was analyzed by immunoperoxidase, confocal microscopy, and Western blotting, and liver regeneration was assessed by proliferating cell nuclear antigen staining. Results showed that caspase-3 and proliferating cell nuclear antigen expression were significantly increased in the BMMNC-treated group. Additionally, confocal microscopy analysis showed cells coexpressing α-SMA and caspase-3 in these animals, suggesting fibrogenic cell death. These results suggest a novel role for BMMNC in liver regeneration during fibrotic disease by stimulating fibrogenic cells apoptosis and hepatocyte proliferation, probably through secretion of specific cytokines that modulate the hepatic microenvironment toward an antifibrogenic balance.
TheXenopushomeobox genepitx3impinges upon somitogenesis and laterality
Authors: Smoczer Cristine , Hooker Lara , Brode Sarah , Wolanski Marian , KhosrowShahian Farhad , Crawford Michael
Published: November 2012

Pitx3 has been identified as the causative locus in a developmental eye mutation associated with mammalian anterior segment dysgenesis, congenital cataracts, and aphakia. In recent studies of frog eye development we discovered that pitx3 expresses symmetrically in the somites and lateral plate mesoderm and asymmetrically during cardiac and gut looping. We report that disruption of pitx3 activity on one side of an embryo relative to the other, either by over- or underexpression of pitx3, elicits a crooked dorsal axis in embryos that is a consequence of a retarded progression through somitogenesis. Unlike in amniotes, Xenopus somites form as cohorts of presomitic cells that rotate perpendicular to the dorsal axis. Since no vertebral anomalies have been reported in mouse and human Pitx3 mutants, we attempt to distinguish whether the segmentation clock is uniquely affected in frog or if the pitx3 perturbation inhibits the cellular changes that are necessary to rotation of presomitic cells. In Xenopus, pitx3 appears to inhibit the rotation of presomitic cell cohorts and to be necessary to the bilaterally symmetric expression of pitx2 in somites.
Influences of phenological differences on leaf-level carbon budget between the upper and lower crown ofLyonia ovalifolia
Authors: Yoshimura Kenichi
Published: November 2012

To assess the significance of leaf phenology on leaf-level carbon budget, I measured seasonal changes in daily carbon budget of the upper and lower leaves within a single crown of Lyonia ovalifolia var. elliptica, a subcanopy tree species. Leaf-level carbon budget was evaluated as the product of area-based assimilation rates and leaf area minus leaf construction cost for a day. The area of the upper leaves gradually increased from spring to summer, whereas that of the lower leaves rapidly increased in early spring. Morphological, biochemical and physiological characteristics in lower leaves matured earlier than in upper leaves. Leaves in the lower crown produced a large amount of photosynthate (1.35 mg C·day−1) using the high light intensity of early spring. On the other hand the highest assimilation rate (5.23 mg C·day−1) was observed in late spring in the upper crown. Phenological differences in morphological and physiological characteristics among leaves in different positions within a crown can be interpreted as the acclimation to the seasonal changes in light acquisition for a leaf.
Theoretical study on the reaction mechanism of vinyl acetate with OH radicals in the atmosphere
Authors: Zhao Yan , Sun Haitao , Wang Renjun , Gao Fei
Published: November 2012

The reaction mechanisms of vinyl acetate with OH radicals in the atmosphere have been studied using the density functional theory method. The geometry parameters and frequencies of all of the stationary points are calculated at the MPWB1K level with the 6-31G(d,p) basis sets. The single-point energy calculations are carried out at the MPWB1K/6-311+G(3df,2pd) level. The detailed profiles of the potential energy surfaces for the reactions are constructed. Two OH addition and three H abstraction reaction pathways are considered for the reaction of vinyl acetate with OH radicals. The theoretical study shows that the most energetically favorable isomer is that of OH addition to the terminal carbon positions (C1 atom). The α-ester rearrangement, which is characteristic of ester oxidation processes, is confirmed to be thermodynamically and kinetically favorable. The main products of the OH-initiated atmospheric oxidation of vinyl acetate are formaldehyde, formic acetic anhydride, and acetic acid.
The complexity of cormorants: stable isotopes reveal multiple prey sources and feeding site switching
Authors: Bugajski Aleksandra , Reudink Matthew W. , Doucette Jennifer L. , Franks Samantha E. , Wissel Björn , Somers Christopher M.
Published: November 2012

Conflict between cormorants (Phalacrocorax spp.) and humans over fisheries is currently one of the most widespread wildlife management issues in the world. Cormorant impact assessments typically assume a single source of prey near the breeding colony. However, cormorants can fly long distances (>20 km), resulting in fish removal from multiple areas. Knowledge of the source of cormorant prey is critical for fisheries impact assessments. Carbon and nitrogen stable isotopes values from fish in double-crested cormorant (Phalacrocorax auritus) regurgitations revealed several prey sources for breeding birds in north-central Saskatchewan, Canada. Cormorants also switched feeding locations on a daily and seasonal basis. Foraging patterns inferred by stable isotope analysis closely paralleled observations of relative cormorant densities on different lakes. Up to 80% of prey came from areas well removed from the breeding colony lake (≤30 km). Cormorant foraging ecology can be complex and may be driven by factors independent of breeding colony site selection. The approach of estimating biomass removal from breeding colony lakes as the guideline for management decisions may be invalid in many locations.
Advanced formwork method integrated with a layout planning model for tall building construction
Authors: Kim Taehoon , Lim Hyunsu , Lee Ung-Kyun , Cha Minsoo , Cho Hunhee , Kang Kyung-In
Published: November 2012

Recent increases in the number of irregularly shaped tall buildings have created a need for more applicable formwork methods and automated support for formwork layout planning, which has mainly depended on heuristic approaches based on the intuitive judgment of experienced engineers. This study proposes a new table formwork method integrated with a systematic layout planning approach for tall building construction. Adjustable subunits of the formwork cope with diverse building shapes and the software-based mathematical model helps practitioners make useful layouts for the method with minimal time and effort. In a case study, the proposed layout planning model offered lower costs and improved work efficiency in less time than the heuristic approach. Supported by the planning model, our advanced formwork method showed a 15.5% increase in covered area of irregularly shaped building floors and a 23.9% decrease in material costs compared with existing table formwork methods.
A note on sharp-crested weirs and weirs of finite crest length
Authors: Azimi Amir Hossein , Rajaratnam Nallamuthu , Zhu David Z.
Published: November 2012

This note presents a brief comparison between the discharge over a sharp-crested weir and a finite crest length weir, with either a sharp-edged or rounded entrance, for any given head over the weir. It has been found that even though in general, the sharp-crested weir passes more flow than the finite crest length weir, there is a small range in which the short-crested form of the finite crest length weir passes more flow than the sharp-crested weir.
Energy absorption potential of light weight concrete floors
Authors: Korol Robert M. , Sivakumaran K.S.
Published: November 2012

This paper investigates the energy absorption potential offered by light weight concrete (LWC) floors, perhaps when a building is poised to collapse from some extreme loading event. It is assumed here that the failure of LWC structural floor slabs would likely result in both break-up and pulverization of the concrete. To estimate the extent to which crushing of large portions of floor slab material would absorb energy, a series of concrete penetration tests employing patch loading was undertaken on scaled down model slabs. Six specimens had free (unconfined) edges, while the other four were confined along the edges. The test results, together with research findings obtained from the mining and milling industry, indicate that such floor systems would likely play an important role in absorbing energy during global collapse catastrophes.
A model for analyzing water reuse and resource recovery potential in urban areas
Authors: Thoren Ryan I. , Atwater Jim , Berube Pierre
Published: November 2012

Expansion and densification of urbanized areas can lead to increased pressure on an area’s water and wastewater infrastructure. This paper presents an optimization model using geographic information systems to locate potential sources and sinks of reclaimed water within an urbanized area. A mathematical solver then maximizes the water reuse using a set of constraints on mass balance, water quality, and electricity used for pumping. Three variations of the model are applied to Vancouver, British Columbia. The first scenario identifies a number of potential industrial sources and sinks for direct cascading with a total potential water savings of 133 400 m3/year. With the implementation of a satellite water reclamation facility in scenario 2, water recycling potential is increased to a maximum of 613 800 m3/year. Scenario 3 expands to include the non-industrial water users and the potential for water reuse is increased to a maximum of 969 200 m3/year.
Bioretention cell efficacy in cold climates: Part 2 — water quality performance
Authors: Khan U.T. , Valeo C. , Chu A. , van Duin B.
Published: November 2012

Field and column experiments were conducted to test the ability of bioretention cells to improve urban runoff quality. The effects of cold climate conditions, media depth, long-term operation, and extreme loading were analyzed. Field experiments demonstrated significant decrease in contaminant mass, which was a function of the large runoff volume capture. Significant decreases in concentration for sediment (96%), biochemical oxygen demand (BOD, 8%), and total phosphorus (0.6%) were noted. Long-term simulation experiments demonstrated a decrease in effluent concentration over time, suggesting a dependence on media chemistry. Sediment and BOD capture remained high throughout the testing period. Media depth did not impact performance in laboratory experiments. Extreme loading experiments proved that the effluent concentration of contaminants was independent of the influent concentration. Cold climate conditions did not have a significant impact on performance in both field and column experiments.
EXPLICIT LOCAL BUCKLING ANALYSIS OF ROTATIONALLY- AND VERTICALLY-RESTRAINED ORTHOTROPIC PLATES UNDER UNIAXIAL COMPRESSION
Authors: HUO XUPING , QIAO PIZHONG
Published: November 2012

In this paper, explicit local buckling analysis of orthotropic plates subjected to uniaxial compression with two loaded edges simply-supported and two unloaded edges supported by combined vertical and rotational restraining springs is presented. Based on the total potential energy function, the eigenvalue problem is formulated by treating the buckled shape functions as the admissible functions that satisfy the boundary conditions of the rectangular plates. Closed-form and approximate local buckling solutions of the combined rotationally- and vertically-restrained orthotropic plates, as well as explicit formulas for the critical buckling load and critical aspect ratio under the uniform compression, are obtained. By adjusting the stiffness of the rotational and vertical restraining springs, explicit local buckling solutions are established for eight simple cases of boundary conditions. To verify the explicit solutions, numerical analyses of orthotropic plates using the exact transcendental and finite element methods are conducted, for which reasonable agreement has been obtained between the explicit and numerical solutions, particularly for the simplified cases. The explicit solution obtained in this study can be used to facilitate the buckling analysis of composite laminated structures with different boundary conditions or joint connections as parts of stiffened and thin-walled structures by treating them as discrete plates with restrained boundary conditions.
Principles Underlying the Use of Multiple Informants' Reports
Authors: De Los Reyes Andres , Thomas Sarah A. , Goodman Kimberly L. , Kundey Shannon M.A.
Published: November 2012

Researchers use multiple informants' reports to assess and examine behavior. However, informants' reports commonly disagree. Informants' reports often disagree in their perceived levels of a behavior (“low” versus “elevated” mood), and examining multiple reports in a single study often results in inconsistent findings. Although researchers often espouse taking a multi-informant assessment approach, they frequently address informant discrepancies using techniques that treat discrepancies as measurement error. Yet, recent work indicates that researchers in a variety of fields often may be unable to justify treating informant discrepancies as measurement error. In this review, the authors advance a framework (Operations Triad Model) outlining general principles for using and interpreting informants' reports. Using the framework, researchers can test whether or not they can extract meaningful information about behavior from discrepancies among multiple informants' reports. The authors provide supportive evidence for this framework and discuss its implications for hypothesis testing, study design, and quantitative review.
Renal Transporters in Drug Development
Authors: Morrissey Kari M. , Stocker Sophie L. , Wittwer Matthias B. , Xu Lu , Giacomini Kathleen M.
Published: November 2012

The kidney plays a vital role in the body's defense against potentially toxic xenobiotics and metabolic waste products through elimination pathways. In particular, secretory transporters in the proximal tubule are major determinants of the disposition of xenobiotics, including many prescription drugs. In the past decade, considerable progress has been made in understanding the impact of renal transporters on the disposition of many clinically used drugs. In addition, renal transporters have been implicated as sites for numerous clinically important drug-drug interactions. This review begins with a description of renal drug handling and presents relevant equations for the calculation of renal clearance, including filtration and secretory clearance. In addition, data on the localization, expression, substrates, and inhibitors of renal drug transporters are tabulated. The recent US Food and Drug Administration drug-drug interaction draft guidance as it pertains to the study of renal drug transporters is presented. Renal drug elimination in special populations and transporter splicing variants are also described.
Structure-Function of the G Protein–Coupled Receptor Superfamily
Authors: Katritch Vsevolod , Cherezov Vadim , Stevens Raymond C.
Published: November 2012

During the past few years, crystallography of G protein–coupled receptors (GPCRs) has experienced exponential growth, resulting in the determination of the structures of 16 distinct receptors—9 of them in 2012 alone. Including closely related subtype homology models, this coverage amounts to approximately 12% of the human GPCR superfamily. The adrenergic, rhodopsin, and adenosine receptor systems are also described by agonist-bound active-state structures, including a structure of the receptor–G protein complex for the β2-adrenergic receptor. Biochemical and biophysical techniques, such as nuclear magnetic resonance and hydrogen-deuterium exchange coupled with mass spectrometry, are providing complementary insights into ligand-dependent dynamic equilibrium between different functional states. Additional details revealed by high-resolution structures illustrate the receptors as allosteric machines that are controlled not only by ligands but also by ions, lipids, cholesterol, and water. This wealth of data is helping redefine our knowledge of how GPCRs recognize such a diverse array of ligands and how they transmit signals 30 angstroms across the cell membrane; it also is shedding light on a structural basis of GPCR allosteric modulation and biased signaling.
Rediscovering the Core of Public Health
Authors: Teutsch Steven M. , Fielding Jonathan E.
Published: November 2012

The success of public health has been its ability to understand contemporary health problems, to communicate the needs successfully, to identify solutions, and to implement them through programs and policies. In the past 50 years, those successes can be attributed largely to control of infectious disease, improved maternal and child health, delivery of other personal health care services, and changes in behaviors, particularly smoking. Yet health is primarily a product of our social, cultural, and physical environments. To continue to improve the nation's health and reduce disparities, public health needs to return to its historical roots and engage with other sectors to create healthier communities. To do so requires expanding public health skills in areas such as quantitative policy analysis, communication, and community engagement.
Psychoactive bacteriaLactobacillus rhamnosus(JB-1) elicits rapid frequency facilitation in vagal afferents
Authors: Perez-Burgos Azucena , Wang Bingxian , Mao Yu-Kang , Mistry Bhavik , Neufeld Karen-Anne McVey , Bienenstock John , Kunze Wolfgang
Published: November 2012

Mounting evidence supports the influence of the gut microbiome on the local enteric nervous system and its effects on brain chemistry and relevant behavior. Vagal afferents are involved in some of these effects. We previously showed that ingestion of the probiotic bacterium Lactobacillus rhamnosus (JB-1) caused extensive neurochemical changes in the brain and behavior that were abrogated by prior vagotomy. Because information can be transmitted to the brain via primary afferents encoded as neuronal spike trains, our goal was to record those induced by JB-1 in vagal afferents in the mesenteric nerve bundle and thus determine the nature of the signals sent to the brain. Male Swiss Webster mice jejunal segments were cannulated ex vivo, and serosal and luminal compartments were perfused separately. Bacteria were added intraluminally. We found no evidence for translocation of labeled bacteria across the epithelium during the experiment. We recorded extracellular multi- and single-unit neuronal activity with glass suction pipettes. Within minutes of application, JB-1 increased the constitutive single- and multiunit firing rate of the mesenteric nerve bundle, but Lactobacillus salivarius (a negative control) or media alone were ineffective. JB-1 significantly augmented multiunit discharge responses to an intraluminal distension pressure of 31 hPa. Prior subdiaphragmatic vagotomy abolished all of the JB-1-evoked effects. This detailed exploration of the neuronal spike firing that encodes behavioral signaling to the brain may be useful to identify effective psychoactive bacteria and thereby offer an alternative new perspective in the field of psychiatry and comorbid conditions.
Heterogeneous nuclear ribonucleoprotein A2/B1 is a tissue-specific aldosterone target gene with prominent induction in the rat distal colon
Authors: Hernández-Díaz Iván , Giraldez Teresa , Morales Silvia , Hernandez Guadalberto , Salido Eduardo , Canessa Cecilia M. , Alvarez de la Rosa Diego
Published: November 2012

The steroid hormone aldosterone enhances transepithelial Na+reabsorption in tight epithelia and is crucial to achieve extracellular volume homeostasis and control of blood pressure. One of the main transport pathways regulated by aldosterone involves the epithelial Na+channel (ENaC), which constitutes the rate-limiting step of Na+reabsorption in parts of the distal nephron and the collecting duct, the distal colon, and sweat and salivary glands. Although these epithelial tissues share the same receptor for aldosterone (mineralocorticoid receptor, MR), and the same transport system (ENaC), it has become clear that the molecular mechanisms involved in the modulation of channel activity are tissue-specific. Recent evidence suggests that aldosterone controls transcription and also translation of ENaC subunits in some cell types. A possible pathway for translational regulation is binding of regulatory proteins to ENaC subunit mRNAs, such as the heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1). In this study, we examined whether hnRNP A2/B1 is an aldosterone-target gene in vivo. Our data show that physiological levels of aldosterone markedly induce hnRNP A2/B1 expression in an early and sustained manner in the late distal colon epithelium but not in other aldosterone-target tissues. The effect depends on MR but not on glucocorticoid receptor activity. We also demonstrate that the genomic region upstream of hnRNP A2/B1 contains aldosterone-responsive elements involved in the control of gene expression. We hypothesize that hnRNP A2/B1 is involved in the tissue-specific regulation of ENaC biosynthesis and may coordinate the response of other genes relevant for transepithelial Na+reabsorption by aldosterone.
Probiotics prevent necrotizing enterocolitis by modulating enterocyte genes that regulate innate immune-mediated inflammation
Authors: Ganguli Kriston , Meng Di , Rautava Samuli , Lu Lei , Walker W. Allan , Nanthakumar Nanda
Published: November 2012

Necrotizing enterocolitis (NEC), an extensive intestinal inflammatory disease of premature infants, is caused, in part, by an excessive inflammatory response to initial bacterial colonization due to the immature expression of innate immune response genes. In a randomized placebo-controlled clinical trial, supplementation of very low birth weight infants with probiotics significantly reduced the incidence of NEC. The primary goal of this study was to determine whether secreted products of these two clinically effective probiotic strains, Bifidobacterium infantis and Lactobacillus acidophilus, prevented NEC by accelerating the maturation of intestinal innate immune response genes and whether both strains are required for this effect. After exposure to probiotic conditioned media (PCM), immature human enterocytes, immature human intestinal xenografts, and primary enterocyte cultures of NEC tissue (NEC-IEC) were assayed for an IL-8 and IL-6 response to inflammatory stimuli. The latter two models were also assayed for innate immune response gene expression. In the immature xenograft, PCM exposure significantly attenuated LPS and IL-1β-induced IL-8 and IL-6 expression, decreased TLR2 mRNA and TLR4 mRNA, and increased mRNA levels of specific negative regulators of inflammation, SIGIRR and Tollip. In NEC-IEC, PCM decreased TLR2-dependent IL-8 and IL-6 induction and increased SIGIRR and Tollip expression. The attenuated inflammatory response with PCM was reversed with Tollip siRNA-mediated knockdown. The anti-inflammatory secreted factor is a 5- to 10-kDa molecule resistant to DNase, RNase, protease, heat stress, and acid exposure. B. infantis-conditioned media showed superior anti-inflammatory properties to that of L. acidophilus in immature human enterocytes, suggesting a strain specificity to this effect. We conclude that PCM promotes maturation of innate immune response gene expression, potentially explaining the protective effects of probiotics in clinical NEC.
Hepatic overexpression ofAbcb11in mice promotes the conservation of bile acids within the enterohepatic circulation
Authors: Henkel Anne S. , Gooijert Karin E. R. , Havinga Rick , Boverhof Renze , Green Richard M. , Verkade Henkjan J.
Published: November 2012

The bile salt export pump, encoded by ABCB11, is the predominant canalicular transport protein for biliary bile acid secretion. The level of ABCB11 expression in humans is widely variable yet the impact of this variability on human disease is not well defined. We aim to determine the effect of hepatic Abcb11 overexpression on the enterohepatic circulation (EHC) in mice. We used a stable isotope dilution technique in transgenic mice overexpressing hepatic Abcb11 (TTR- Abcb11) to determine the pool size, fractional turnover rate (FTR), and synthesis rate of the primary bile acid, cholic acid (CA). The gallbladder was cannulated to determine bile flow, bile acid composition, and the biliary secretion rates of CA, total bile acids, phospholipid, and cholesterol. The combined data allowed for estimation of the CA cycling time and the fraction of CA lost per cycle. Hepatic and intestinal gene and protein expression were determined by qPCR and Western blot. Abcb11 overexpression strongly decreased FTR and synthesis rate of CA. Abcb11 overexpression decreased the fraction of CA that was lost per cycle of the EHC. Hepatic expression of Cyp7a1 was suppressed by nearly 50% and ileal expression of FGF15 was increased more than eightfold in TTR- Abcb11 mice. Despite the increased intestinal reabsorption of bile acids, ileal Asbt expression was suppressed. Hepatic Abcb11 overexpression in mice increases the conservation of bile acids within the enterohepatic circulation. These data provide strong evidence for the existence of feed-forward communication between hepatic expression of a bile acid transport protein and the intestine.
Neonatal maternal deprivation sensitizes voltage-gated sodium channel currents in colon-specific dorsal root ganglion neurons in rats
Authors: Hu Shufen , Xiao Ying , Zhu Liyan , Li Lin , Hu Chuang-Ying , Jiang Xinghong , Xu Guang-Yin
Published: November 2012

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by abdominal pain in association with altered bowel movements. The underlying mechanisms of visceral hypersensitivity remain elusive. This study was designed to examine the role for sodium channels in a rat model of chronic visceral hyperalgesia induced by neonatal maternal deprivation (NMD). Abdominal withdrawal reflex (AWR) scores were performed on adult male rats. Colon-specific dorsal root ganglion (DRG) neurons were labeled with DiI and acutely dissociated for measuring excitability and sodium channel current under whole-cell patch-clamp configurations. The expression of NaV1.8 was analyzed by Western blot and quantitative real-time PCR. NMD significantly increased AWR scores, which lasted for ∼6 wk in an association with hyperexcitability of colon DRG neurons. TTX-resistant but not TTX-sensitive sodium current density was greatly enhanced in colon DRG neurons in NMD rats. Compared with controls, activation curves showed a leftward shift in NMD rats whereas inactivation curves did not differ significantly. NMD markedly accelerated the activation time of peak current amplitude without any changes in inactivation time. Furthermore, NMD remarkably enhanced expression of NaV1.8 at protein levels but not at mRNA levels in colon-related DRGs. The expression of NaV1.9 was not altered after NMD. These data suggest that NMD enhances TTX-resistant sodium activity of colon DRG neurons, which is most likely mediated by a leftward shift of activation curve and by enhanced expression of NaV1.8 at protein levels, thus identifying a specific molecular mechanism underlying chronic visceral pain and sensitization in patients with IBS.
The impact of arousal state, sex, and sleep apnea on the magnitude of progressive augmentation and ventilatory long-term facilitation
Authors: Syed Ziauddin , Lin Ho-Sheng , Mateika Jason H.
Published: November 2012

We examined the impact of arousal state, sex, and obstructive sleep apnea (OSA) on the magnitude of progressive augmentation of the hypoxic ventilatory response and ventilatory long-term facilitation (vLTF). We also examined whether exposure to intermittent hypoxia during sleep has an impact on the apnea-hypopnea index (AHI) in individuals with OSA. Ten men and seven women with OSA, along with ten healthy men and ten healthy women, were exposed to twelve 2-min episodes of hypoxia (end-tidal Po2: 50 Torr) in the presence of sustained hypercapnia (end-tidal Pco2: 3 Torr above baseline), followed by a 30-min recovery period during wakefulness and sleep. The OSA participants completed an additional sham study during sleep. The AHI during the first hour of sleep following the intermittent hypoxia and sham protocols were compared. Progressive augmentation was only evident during wakefulness and was enhanced in the OSA participants. vLTF was evident during wakefulness and sleep. When standardized to baseline, vLTF was greater during wakefulness and was enhanced in the OSA group (men: wakefulness 1.39 ± 0.08 vs. sleep 1.14 ± 0.03; women: wakefulness 1.35 ± 0.03 vs. sleep 1.16 ± 0.05 fraction of baseline; P ≤ 0.001) compared with control (men: wakefulness 1.19 ± 0.03 vs. sleep 1.09 ± 0.03; women: wakefulness 1.26 ± 0.05 vs. sleep 1.08 ± 0.04 fraction of baseline; P ≤ 0.001). The AHI following exposure to intermittent hypoxia was increased (intermittent hypoxia 72.8 ± 7.3 vs. sham 56.5 ± 7.0 events/h; P ≤ 0.01). Sex-related differences were not observed for the primary measures. We conclude that progressive augmentation is not evident, and the magnitude of vLTF is diminished during sleep compared with wakefulness in men and women. However, when present, the phenomena are enhanced in individuals with OSA. The AHI data indicate that, under the prevailing experimental conditions, vLTF did not serve to mitigate apnea severity.
Vasculoprotective effect of U50,488H in rats exposed to chronic hypoxia: role of Akt-stimulated NO production
Authors: Li Juan , Shi Quan-Xing , Fan Rong , Zhang Li-Jun , Zhang Shu-Miao , Guo Hai-Tao , Wang Yue-Min , Kaye Aaron Joshua , Kaye Alan David , Bueno Franklin Rivera , Xu Xue-Zeng , Yu Shi-Qiang , Yi Ding-Hua , Pei Jian-Ming
Published: November 2012

Impairment of pulmonary endothelium function in the pulmonary artery is a direct result of chronic hypoxia. This study is to investigate the vasculoprotective effects of U50,488H (a selective κ-opioid receptor agonist) and its underlying mechanism in hypoxia-induced pulmonary artery endothelial functional injury. Chronic hypoxia was simulated by exposing the rats to 10% oxygen for 2 wk. After hypoxia, right ventricular pressure (RVP) and right ventricular hypertrophy index (RVHI) were measured. The pulmonary vascular dysfunction, effect of nitric oxide synthase inhibitor (l-NAME) on the relaxation of U50,488H, and level of nitric oxide (NO) were determined. In vitro, the signaling pathway involved in the anti-apoptotic effect of U50,488H was investigated. Cultured endothelial cells were subjected to simulated hypoxia, and cell apoptosis was determined by TUNEL staining. U50,488H (1.25 mg/kg) significantly reduced RVP and RVHI in hypoxia. U50,488H markedly improved both pulmonary endothelial function (maximal vasorelaxation in response to ACh: 74.9 ± 1.8%, n = 6, P <0.01 vs. hypoxia for 2 wk group) and increased total NO production (1.65 fold). U50,488H relaxed the pulmonary artery rings of the hypoxic rats. This effect was partly abolished by l-NAME. In cells, U50,488H both increased NO production and reduced hypoxia-induced apoptosis. Moreover, pretreatment with nor-binaltorphimine (nor-BNI, a selective κ-opioid receptor antagonist), PI3K inhibitor, Akt inhibitor or l-NAME almost abolished anti-apoptotic effect exerted by U50,488H. U50,488H resulted in increases in Akt and eNOS phosphorylation. These results demonstrate that pretreatment with U50,488H attenuates hypoxia-induced pulmonary vascular endothelial dysfunction in an Akt-dependent and NO-mediated fashion.
Characterization of Rearrangements Involving the ALK Gene Reveals a Novel Truncated Form Associated with Tumor Aggressiveness in Neuroblastoma
Authors: Cazes Alex , Louis-Brennetot Caroline , Mazot Pierre , Dingli Florent , Lombard Bérangère , Boeva Valentina , Daveau Romain , Cappo Julie , Combaret Valérie , Schleiermacher Gudrun , Jouannet Stéphanie , Ferrand Sandrine , Pierron Gaëlle , Barillot Emmanuel , Loew Damarys , Vigny Marc , Delattre Olivier , Janoueix-Lerosey Isabelle
Published: November 2012

Activating mutations of the ALK gene have been identified in sporadic and familial cases of neuroblastoma (NB), a cancer of the peripheral nervous system, and are thought to be the primary mechanism of oncogenic activation of this receptor in this pediatric neoplasm. To address the possibility that ALK activation may occur through genomic rearrangements as detected in other cancers, we first took advantage of high-resolution array-comparative genomic hybridization to search for ALK rearrangements in NB samples. Using complementary experiments by capture/paired-end sequencing and FISH experiments, various types of rearrangements were fully characterized, including partial gains or amplifications, in several NB cell lines and primary tumors. In the CLB-Bar cell line, we described a genomic rearrangement associated with an amplification of the ALK locus, leading to the expression of a 170 kDa protein lacking part of the extracellular domain encoded by exons 4 to 11, named ALKΔ4-11. Analysis of genomic DNA from the tumor at diagnosis and relapse revealed that the ALK gene was amplified at diagnosis but that the rearranged ALK allele was observed at the relapse stage only, suggesting that it may be implicated in tumor aggressiveness. Consistently, oncogenic and tumorigenic properties of the ALKΔ4-11 variant were shown after stable expression in NIH3T3 cells. Moreover, we documented an increased constitutive kinase activity of this variant, as well as an impaired maturation and retention into intracellular compartments. These results indicate that genomic rearrangements constitute an alternative mechanism to ALK point mutations resulting in receptor activation. Cancer Res; 73(1); 195–204. ©2012 AACR.
Oncostatin M Modulates the Mesenchymal–Epithelial Transition of Lung Adenocarcinoma Cells by a Mesenchymal Stem Cell-Mediated Paracrine Effect
Authors: Wang Mong-Lien , Pan Chih-Ming , Chiou Shih-Hwa , Chen Wen-Hsin , Chang Hsiang-Yi , Lee Oscar Kuang-Sheng , Hsu Han-Sui , Wu Cheng-Wen
Published: November 2012

Mesenchymal stem cells (MSC) are strongly associated with tumor progression and have been used as novel cell-based agents to deliver anticancer drugs to tumors. However, controversies about the direct involvement of MSCs in tumor progression suggest that MSCs mediate tumor progression in a cancer type-dependent manner. In this report, we analyzed the functional interactions between human MSCs and lung adenocarcinoma (LAC) cells to determine the therapeutic potential of MSCs in lung cancer. We showed that MSCs effectively inhibited the migration, invasion, and cell-cycle progression of several LAC cell lines. MSCs also enhanced the mesenchymal–epithelial transition (MET) pathway, as evidenced by the reduction of several epithelial–mesenchymal transition-related markers in LAC cells cocultured with MSCs or in MSC-conditioned medium (MSC-CM). By cytokine array analysis, we determined that Oncostatin M (OSM), a differentiation-promoting cytokine, was elevated in the MSC-CM derived from primary MSC cultures. Furthermore, OSM treatment had the same effects as MSC-CM on LAC, whereas neutralizing antibodies to OSM reversed them. Notably, short hairpin RNAs against STAT1, an important downstream target of OSM, hindered the OSM-dependent induction of MET. In vivo xenograft tumor studies indicated that OSM inhibited tumor formation and metastasis of LAC cells, whereas neutralizing OSM in the MSC-CM hampered its inhibitory effects. In conclusion, this study showed that OSM is a paracrine mediator of MSC-dependent inhibition of tumorigenicity and activation of MET in LAC cells. These effects of OSM may serve as a basis for the development of new drugs and therapeutic interventions targeting cancer cells. Cancer Res; 72(22); 6051–64. ©2012 AACR.
RANKL Expression, Function, and Therapeutic Targeting in Multiple Myeloma and Chronic Lymphocytic Leukemia
Authors: Schmiedel Benjamin Joachim , Scheible Carolin Andrea , Nuebling Tina , Kopp Hans-Georg , Wirths Stefan , Azuma Miyuki , Schneider Pascal , Jung Gundram , Grosse-Hovest Ludger , Salih Helmut Rainer
Published: November 2012

Bone destruction is a prominent feature of multiple myeloma, but conflicting data exist on the expression and pathophysiologic involvement of the bone remodeling ligand RANKL in this disease and the potential therapeutic benefits of its targeted inhibition. Here, we show that RANKL is expressed by primary multiple myeloma and chronic lymphocytic leukemia (CLL) cells, whereas release of soluble RANKL was observed exclusively with multiple myeloma cells and was strongly influenced by posttranscriptional/posttranslational regulation. Signaling via RANKL into multiple myeloma and CLL cells induced release of cytokines involved in disease pathophysiology. Both the effects of RANKL on osteoclastogenesis and cytokine production by malignant cells could be blocked by disruption of RANK–RANKL interaction with denosumab. As we aimed to combine neutralization of RANKL with induction of antibody-dependent cellular cytotoxicity of natural killer (NK) cells against RANKL-expressing malignant cells and as denosumab does not stimulate NK reactivity, we generated RANK-Fc fusion proteins with modified Fc moieties. The latter displayed similar capacity compared with denosumab to neutralize the effects of RANKL on osteoclastogenesis in vitro, but also potently stimulated NK cell reactivity against primary RANKL-expressing malignant B cells, which was dependent on their engineered affinity to CD16. Our findings introduce Fc-optimized RANK-Ig fusion proteins as attractive tools to neutralize the detrimental function of RANKL while at the same time potently stimulating NK cell antitumor immunity. Cancer Res; 73(2); 683–94. ©2012 AACR.
Comparison of two methods for selection of out of hospital treatment in patients with acute pulmonary embolism
Authors: Crobach Monique J. T. , Dolsma Anneke , Donker Marjolein L. , Eijsvogel Michiel , Faber Laura M. , Hofstee Herman M. A. , Kaasjager Karin A. H. , Kruip Marieke J. H. A. , Labots Geert , Melissant Christian F. , Sikkens Michelle S. G. , Huisman Menno V. , Zondag Wendy , den Exter Paul L.
Published: November 2012

The aim of this study is to compare the performance of two clinical decision rules to select patients with acute pulmonary embolism (PE) for outpatient treatment: the Hestia criteria and the simplified Pulmonary Embolism Severity Index (sPESI). From 2008 to 2010, 468 patients with PE were triaged with the Hestia criteria for outpatient treatment: 247 PE patients were treated at home and 221 were treated as inpatients. The outcome of interest was all-cause 30-day mortality. In a post-hoc fashion, the sPESI items were scored and patients were classified according to the sPESI in low and high risk groups. Of the 247 patients treated at home, 189 (77%) patients were classified as low risk according to the sPESI and 58 patients (23%) as high risk. In total, 11 patients died during the first month; two patients treated at home and nine patients treated in-hospital. None of the patients treated at home died of fatal PE. Both the Hestia criteria and sPESI selected >50% of patients as low risk, with good sensitivity and negative predictive values for 30-day mortality: 82% and 99% for the Hestia criteria and 91% and 100% for the sPESI, respectively. The Hestia criteria and the sPESI classified different patients eligible for out-patient treatment, with similar low risks for 30-day mortality. This study suggests that the Hestia criteria may identify a proportion of high risk sPESI patiennts who can be safely treated at home, this however requires further validation.
Differential expression of T-cell genes in blood and bone marrow between ITP patients and controls
Authors: Nookaew Intawat , Wadenvik Hans , Olsson Bob , Jernås Margareta
Published: November 2012

Primary immune thrombocytopenia (ITP) is an autoimmune disease characterised by premature platelet destruction in spleen, liver and bone marrow and a diminished production of platelets. T-cells are important in all forms of autoimmunity including ITP; however, very little is known about T-cells in organs where platelets are destroyed. Our aim was to investigate differences in gene expression in peripheral blood-derived T-cells and bone marrow-derived T-cells between ITP patients and controls. T-cells and subsequent RNA were isolated from blood and bone marrow from chronic ITP patients and healthy controls followed by DNA microarray analysis. There were 1554 differentially expressed genes in peripheral blood-derived T-cells and 976 in bone marrow-derived T-cells between ITP patients and controls and three genes were verified with real-time PCR. Using Gene Ontology functional enrichment analysis we found that genes involved in growth, development, migration, chemotaxis, adhesion and apoptosis were enriched in bone marrow-derived T-cells in ITP. Immune-related genes involved in T-helper cell differentiation, T-cell chemotaxis, migration, immunoglobulin-mediated immune response and classical and alternative pathway complement activation were also enriched in bone marrow-derived T-cells in ITP. Only 213 T-cell genes were differentially expressed in both blood and bone marrow between ITP patients and controls. In conclusion, our findings show that genes involved in major pathophysiologic pathways in ITP such as T-helper cell differentiation, autoantibody response and complement activation are altered in bone marrow-derived T-cells in ITP patients compared with controls. This further supports the concept that bone marrow is an important compartment in ITP.