bluuebunny/crossref_metadata_2025_split huggingface dataset:
Somatic and gastrointestinal in vivo biotransformation rates of hydrophobic chemicals in fish
Authors: Lo Justin C. , Campbell David A. , Kennedy Christopher J. , Gobas Frank A.P.C. 
Published: May 2015

Abstract

To improve current bioaccumulation assessment methods, a methodology is developed, applied, and investigated for measuring in vivo biotransformation rates of hydrophobic organic substances in the body (soma) and gastrointestinal tract of the fish. The method resembles the Organisation for Economic Co-operation and Development (OECD) 305 dietary bioaccumulation test but includes reference chemicals to determine both somatic and gastrointestinal biotransformation rates of test chemicals. Somatic biotransformation rate constants for the test chemicals ranged between 0 d–1 and 0.38 (standard error [SE] 0.03)/d–1. Gastrointestinal biotransformation rate constants varied from 0 d–1 to 46 (SE 7) d–1. Gastrointestinal biotransformation contributed more to the overall biotransformation in fish than somatic biotransformation for all test substances but 1. Results suggest that biomagnification tests can reveal the full extent of biotransformation in fish. The common presumption that the liver is the main site of biotransformation may not apply to many substances exposed through the diet. The results suggest that the application of quantitative structure-activity relationships (QSARs) for somatic biotransformation rates and hepatic in vitro models to assess the effect of biotransformation on bioaccumulation can underestimate biotransformation rates and overestimate the biomagnification potential of chemicals that are biotransformed in the gastrointestinal tract. With some modifications, the OECD 305 test can generate somatic and gastrointestinal biotransformation data to develop biotransformation QSARs and test in vitro–in vivo biotransformation extrapolation methods. Environ Toxicol Chem 2015;34:2282–2294. © 2015 SETAC
Surface coal mining influences on macroinvertebrate assemblages in streams of the Canadian Rocky Mountains
Authors: Kuchapski Kathryn A. , Rasmussen Joseph B. 
Published: May 2015

Abstract

To determine the region-specific impacts of surface coal mines on macroinvertebrate community health, chemical and physical stream characteristics and macroinvertebrate family and community metrics were measured in surface coal mine-affected and reference streams in the Canadian Rocky Mountains. Water chemistry was significantly altered in mine-affected streams, which had elevated conductivity, alkalinity, and selenium and ion concentrations compared with reference conditions. Multivariate redundancy analysis (RDA) indicated alterations in macroinvertebrate communities downstream of mine sites. In RDA ordination, Ephemeroptera family densities, family richness, Ephemeroptera, Plecoptera, Trichoptera (EPT) richness, and % Ephemeroptera declined, whereas densities of Capniidae stoneflies increased along environmental gradients defined by variables associated with mine influence including waterborne Se concentration, alkalinity, substrate embeddedness, and interstitial material size. Shifts in macroinvertebrate assemblages may have been the result of multiple region-specific stressors related to mining influences including selenium toxicity, ionic toxicity, or stream substrate modifications. Environ Toxicol Chem 2015;34:2138–2148. © 2015 SETAC
Characteristics of suspended solids affect bifenthrin toxicity to the calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi
Authors: Parry Emily , Lesmeister Sarah , Teh Swee , Young Thomas M. 
Published: May 2015

Abstract

Bifenthrin is a pyrethroid pesticide that is highly toxic to aquatic invertebrates. The dissolved concentration is generally thought to be the best predictor of acute toxicity. However, for the filter-feeding calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi, ingestion of pesticide-bound particles could prove to be another route of exposure. The present study investigated bifenthrin toxicity to E. affinis and P. forbesi in the presence of suspended solids from municipal wastewater effluent and surface water of the San Francisco (CA, USA) Estuary. Suspended solids mitigated the toxicity of total bifenthrin to E. affinis and P. forbesi, but mortality was higher than what would be predicted from dissolved concentrations alone. The results indicate that the toxicity and bioavailability of particle-associated bifenthrin was significantly correlated with counts of 0.5-µm to 2-µm particle sizes. Potential explanations could include direct ingestion of bifenthrin-bound particles, changes in food consumption and feeding behavior, and physical contact with small particles. The complex interactions between pesticides and particles of different types and sizes demonstrate a need for future ecotoxicological studies to investigate the role of particle sizes on aquatic organisms. Environ Toxicol Chem 2015;34:2302–2309. © 2015 SETAC
Inefficiency in macromolecular transport of SCS‐based microcapsules affects viability of primary human mesenchymal stem cells but not of immortalized cells
Authors: Sanz‐Nogués Clara , Horan Jason , Thompson Kerry , Howard Linda , Ryan Gerard , Kassem Moustapha , O'Brien Timothy 
Published: May 2015

AbstractMicrocapsules made of sodium cellulose sulphate (SCS) and poly‐diallyl‐dimethyl‐ammonium chloride (pDADMAC) have been employed to encapsulate a wide range of established cell lines for several applications. However, little is known about the encapsulation of primary cells including human mesenchymal stem cells (hMSCs). Human MSCs are of interest in regenerative medicine applications due to pro‐angiogenic, anti‐inflammatory and immunomodulatory properties, which result from paracrine effects of this cell type. In the present work we have encapsulated primary hMSCs and hMSC‐TERT immortalized cells and compared their behavior and in vitro angiogenic potential. We found that, although both cell types were able to secret angiogenic factors such as VEGF, there was a marked reduction of primary hMSC viability compared to hMSC‐TERT cells when cultured in these microcapsules. Moreover, this applied to other primary cell cultures such as primary human fibroblasts but not to other cell lines such as human embryonic kidney 293 (HEK293) cells. We found that the microcapsule membrane had a molecular weight cut‐off below a critical size, which caused impairment in the diffusion of essential nutrients and had a more detrimental effect on the viability of primary cell cultures compared to cell lines and immortalized cells. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3676–3688, 2015.
Chondroprotective effect of zinc oxide nanoparticles in conjunction with hypoxia on bovine cartilage‐matrix synthesis
Authors: Mirza Eraj Humayun , Pan‐Pan Chong , Wan Ibrahim Wan Mohd Azhar Bin , Djordjevic Ivan , Pingguan‐Murphy Belinda 
Published: May 2015

AbstractArticular cartilage is a tissue specifically adapted to a specific niche with a low oxygen tension (hypoxia), and the presence of such conditions is a key factor in regulating growth and survival of chondrocytes. Zinc deficiency has been linked to cartilage‐related disease, and presence of Zinc is known to provide antibacterial benefits, which makes its inclusion attractive in an in vitro system to reduce infection. Inclusion of 1% zinc oxide nanoparticles (ZnONP) in poly octanediol citrate (POC) polymer cultured in hypoxia has not been well determined. In this study we investigated the effects of ZnONP on chondrocyte proliferation and matrix synthesis cultured under normoxia (21% O2) and hypoxia (5% O2). We report an upregulation of chondrocyte proliferation and sulfated glycosaminoglycan (S‐GAG) in hypoxic culture. Results demonstrate a synergistic effect of oxygen concentration and 1% ZnONP in up‐regulation of anabolic gene expression (Type II collagen and aggrecan), and a down regulation of catabolic (MMP‐13) gene expression. Furthermore, production of transcription factor hypoxia‐inducible factor 1A (HIF‐1A) in response to hypoxic condition to regulate chondrocyte survival under hypoxia is not affected by the presence of 1% ZnONP. Presence of 1% ZnONP appears to act to preserve homeostasis of cartilage in its hypoxic environment. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3554–3563, 2015.
Cardiac‐Specific Disruption of Bin1 in Mice Enables a Model of Stress‐ and Age‐Associated Dilated Cardiomyopathy
Authors: Laury‐Kleintop Lisa D. , Mulgrew Jennifer R. , Heletz Ido , Nedelcoviciu Radu Alexandru , Chang Mee Young , Harris David M. , Koch Walter J. , Schneider Michael D. , Muller Alexander J. , Prendergast George C. 
Published: May 2015

ABSTRACTNon‐compensated dilated cardiomyopathy (DCM) leading to death from heart failure is rising rapidly in developed countries due to aging demographics, and there is a need for informative preclinical models to guide the development of effective therapeutic strategies to prevent or delay disease onset. In this study, we describe a novel model of heart failure based on cardiac‐specific deletion of the prototypical mammalian BAR adapter‐encoding gene Bin1, a modifier of age‐associated disease. Bin1 deletion during embryonic development causes hypertrophic cardiomyopathy and neonatal lethality, but there is little information on how Bin1 affects cardiac function in adult animals. Here we report that cardiomyocyte‐specific loss of Bin1 causes age‐associated dilated cardiomyopathy (DCM) beginning by 8–10 months of age. Echocardiographic analysis showed that Bin1 loss caused a 45% reduction in ejection fraction during aging. Younger animals rapidly developed DCM if cardiac pressure overload was created by transverse aortic constriction. Heterozygotes exhibited an intermediate phenotype indicating Bin1 is haplo‐insufficient to sustain normal heart function. Bin1 loss increased left ventricle (LV) volume and diameter during aging, but it did not alter LV volume or diameter in hearts from heterozygous mice nor did it affect LV mass. Bin1 loss increased interstitial fibrosis and mislocalization of the voltage‐dependent calcium channel Cav1.2, and the lipid raft scaffold protein caveolin‐3, which normally complexes with Bin1 and Cav1.2 in cardiomyocyte membranes. Our findings show how cardiac deficiency in Bin1 function causes age‐ and stress‐associated heart failure, and they establish a new preclinical model of this terminal cardiac disease. J. Cell. Biochem. 116: 2541–2551, 2015. © 2015 Wiley Periodicals, Inc.
A Distinct Role for Interleukin‐6 as a Major Mediator of Cellular Adjustment to an Altered Culture Condition
Authors: Son Hwa‐Kyung , Park Iha , Kim Jue Young , Kim Do Kyeong , Illeperuma Rasika P. , Bae Jung Yoon , Lee Doo Young , Oh Eun‐Sang , Jung Da‐Woon , Williams Darren R. , Kim Jin 
Published: May 2015

ABSTRACTTissue microenvironment adjusts biological properties of different cells by modulating signaling pathways and cell to cell interactions. This study showed that epithelial–mesenchymal transition (EMT)/ mesenchymal–epithelial transition (MET) can be modulated by altering culture conditions. HPV E6/E7‐transfected immortalized oral keratinocytes (IHOK) cultured in different media displayed reversible EMT/MET accompanied by changes in cell phenotype, proliferation, gene expression at transcriptional, and translational level, and migratory and invasive activities. Cholera toxin, a major supplement to culture medium, was responsible for inducing the morphological and biological changes of IHOK. Cholera toxin per se induced EMT by triggering the secretion of interleukin 6 (IL‐6) from IHOK. We found IL‐6 to be a central molecule that modulates the reversibility of EMT based not only on the mRNA level but also on the level of secretion. Taken together, our results demonstrate that IL‐6, a cytokine whose transcription is activated by alterations in culture conditions, is a key molecule for regulating reversible EMT/MET. This study will contribute to understand one way of cellular adjustment for surviving in unfamiliar conditions. J. Cell. Biochem. 116: 2552–2562, 2015. © 2015 The Authors.Journal of Cellular BiochemistryPublished by Wiley Periodicals, Inc.
Early osteoarthritis of the trapeziometacarpal joint is not associated with joint instability during typical isometric loading
Authors: Halilaj Eni , Moore Douglas C. , Patel Tarpit K. , Ladd Amy L. , Weiss Arnold‐Peter C. , Crisco Joseph J. 
Published: May 2015

ABSTRACTThe saddle‐shaped trapeziometacarpal (TMC) joint contributes importantly to the function of the human thumb. A balance between mobility and stability is essential in this joint, which experiences high loads and is prone to osteoarthritis (OA). Since instability is considered a risk factor for TMC OA, we assessed TMC joint instability during the execution of three isometric functional tasks (key pinch, jar grasp, and jar twist) in 76 patients with early TMC OA and 44 asymptomatic controls. Computed tomography images were acquired while subjects held their hands relaxed and while they applied 80% of their maximum effort for each task. Six degree‐of‐freedom rigid body kinematics of the metacarpal with respect to the trapezium from the unloaded to the loaded task positions were computed in terms of a TMC joint coordinate system. Joint instability was expressed as a function of the metacarpal translation and the applied force. We found that the TMC joint was more unstable during a key pinch task than during a jar grasp or a jar twist task. Sex, age, and early OA did not have an effect on TMC joint instability, suggesting that instability during these three tasks is not a predisposing factor in TMC OA. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1639–1645, 2015.
3‐D localization of non‐radioactive strontium in osteoarthritic bone: Role in the dynamic labeling of bone pathological changes
Authors: Panahifar Arash , Cooper David M.L. , Doschak Michael R. 
Published: May 2015

ABSTRACTThe study objective was to visualize regions of bone that undergo pathological mineralization and/or remodeling during pathogenesis of osteoarthritis, by employing non‐radioactive strontium as a dynamic tracer of bone turnover. Post traumatic osteoarthritis was surgically induced in skeletally mature rats, followed by in vivo micro‐CT imaging for 12 weeks to assess bone micro‐structural changes. Rats either received strontium ranelate daily for the entire course of study or only last 10 days before euthanization. Distribution of strontium in bone was assessed in two and three dimensions, using electron probe micro‐analysis (EPMA) and synchrotron dual energy K‐edge subtraction micro‐CT (SRμCT), respectively. Considerable early formation of osteophytes around the collateral ligament attachments and margins of articulating surfaces were observed, followed by subchondral sclerosis at the later stages. Accordingly, strontium was heavily incorporated by mineralizing osteophytes at 4, 8, and 12 weeks post‐surgery, whereas subchondral bone only incorporated strontium between weeks 8–12.This study showed low dose stable strontium can effectively serve as a dynamic tracer of bone turnover to study pathological bone micro‐structural changes, at resolution higher than nuclear medicine. Co‐administration of strontium during therapeutic drug intervention may show enormous utility in assessing the efficacy of those compounds upon adaptive bone physiology. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1655–1662, 2015.
Genipin crosslinking of cartilage enhances resistance to biochemical degradation and mechanical wear
Authors: McGann Megan E. , Bonitsky Craig M. , Jackson Mariah L. , Ovaert Timothy C. , Trippel Stephen B. , Wagner Diane R. 
Published: May 2015

ABSTRACTCollagen crosslinking enhances many beneficial properties of articular cartilage, including resistance to chemical degradation and mechanical wear, but many crosslinking agents are cytotoxic. The purpose of this study was to evaluate the effectiveness of genipin, a crosslinking agent with favorable biocompatibility and cytotoxicity, as a potential treatment to prevent the degradation and wear of articular cartilage. First, the impact of genipin concentration and treatment duration on the viscoelastic properties of bovine articular cartilage was quantified. Next, two short‐term (15 min) genipin crosslinking treatments were chosen, and the change in collagenase digestion, cartilage wear, and the friction coefficient of the tissue with these treatments was measured. Finally, chondrocyte viability after exposure to these genipin treatments was assessed. Genipin treatment increased the stiffness of healthy, intact cartilage in a dose‐dependent manner. The 15‐min crosslinking treatments improved cartilage's resistance to both chemical degradation, particularly at the articular surface, and to damage due to mechanical wear. These enhancements were achieved without sacrificing the low coefficient of friction of the tissue and at a genipin dose that preserved chondrocyte viability. The results of this study suggest that collagen crosslinking via genipin may be a promising preventative treatment to slow the degradation of cartilage. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1571–1579, 2015.
Therapeutic opportunities to prevent post‐traumatic arthritis: Lessons from the natural history of arthritis after articular fracture
Authors: Olson Steven A. , Furman Bridgette D. , Kraus Virginia B. , Huebner Janet L. , Guilak Farshid 
Published: May 2015

ABSTRACTAn estimated 12% of patients seeking surgical intervention for symptomatic arthritis have an etiology of post‐traumatic arthritis (PTA). The onset of PTA is rapid in the setting of articular fracture (AF). The investigation began with development of a murine model of a closed AF that develops PTA. In the process of characterizing this model a technique was developed for assessing quantitative synovial fluid biomarker concentrations. The work began with observations of the natural history of PTA development in the C57BL/6 strain of mice. A species of mice (MRL/MpJ) was found that is protected from PTA after AF. Further work identified key differences between mouse strains that did and did not develop PTA. This knowledge led to an intervention based on anti‐cytokine (interleukin 1 receptor antagonist, (IL‐1Ra) delivery in the C57BL/6 strain of mice that successfully prevented PTA following AF. This success in preventing PTA in the murine model has elucidated several important clinical implications: 1) Pro‐inflammatory cytokines play an important role in the development of PTA after joint injury, 2) Pharmacologic intervention can lessen the severity of PTA after an AF, and 3) The murine AF model of joint injury provides a novel means of studying mechanisms of PTA development. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1266–1277, 2015.
The fractionated dipole antenna: A new antenna for body imaging at 7 Tesla
Authors: Raaijmakers Alexander J.E. , Italiaander Michel , Voogt Ingmar J. , Luijten Peter R. , Hoogduin Johannes M. , Klomp Dennis W.J. , van den Berg Cornelis A.T. 
Published: May 2015

PurposeDipole antennas in ultrahigh field MRI have demonstrated advantages over more conventional designs. In this study, the fractionated dipole antenna is presented: a dipole where the legs are split into segments that are interconnected by capacitors or inductors.MethodsA parameter study has been performed on dipole antenna length using numerical simulations. A subsequent simulation study investigates the optimal intersegment capacitor/inductor value. The resulting optimal design has been constructed and compared to a previous design, the single‐side adapted dipole (SSAD) by simulations and measurements. An array of eight elements has been constructed for prostate imaging on four subjects (body mass index 20–27.5) using 8 × 2 kW amplifiers.ResultsFor prostate imaging at 7T, lowest peak local specific‐absorption rate (SAR) levels are achieved if the antenna is 30 cm or longer. A fractionated dipole antenna design with inductors between segments has been chosen to achieve even lower SAR levels and more homogeneous receive sensitivities.ConclusionWith the new design, good quality prostate images are acquired. SAR levels are reduced by 41% to 63% in comparison to the SSAD. Coupling levels are moderate (average nearest neighbor: −14.6 dB) for each subject and prostate
levels range from 12 to 18 μT. Magn Reson Med 75:1366–1374, 2016. © 2015 Wiley Periodicals, Inc.
Influence of water and fat heterogeneity on fat‐referenced MR thermometry
Authors: Baron Paul , Deckers Roel , Bouwman Job G. , Bakker Chris J. G. , de Greef Martijn , Viergever Max A. , Moonen Chrit T. W. , Bartels Lambertus W. 
Published: May 2015

PurposeTo investigate the effect of the aqueous and fatty tissue magnetic susceptibility distribution on absolute and relative temperature measurements as obtained directly from the water/fat (w/f) frequency difference.MethodsAbsolute thermometry was investigated using spherical phantoms filled with pork and margarine, which were scanned in three orthogonal orientations. To evaluate relative fat referencing, multigradient echo scans were acquired before and after heating pork tissue via high‐intensity focused ultrasound (HIFU). Simulations were performed to estimate the errors that can be expected in human breast tissue.ResultsThe sphere experiment showed susceptibility‐related errors of 8.4°C and 0.2°C for pork and margarine, respectively. For relative fat referencing measurements, fat showed pronounced phase changes of opposite polarity to aqueous tissue. The apparent mean temperature for a numerical breast model assumed to be 37°C was 47.2 ± 21.6°C. Simulations of relative fat referencing for a HIFU sonication (ΔT = 29.7°C) yielded a maximum temperature error of 6.6°C compared with 2.5°C without fat referencing.ConclusionVariations in the observed frequency difference between water and fat are largely due to variations in the w/f spatial distribution. This effect may lead to considerable errors in absolute MR thermometry. Additionally, fat referencing may exacerbate rather than correct for proton resonance frequency shift–temperature measurement errors. Magn Reson Med 75:1187–1197, 2016. © 2015 Wiley Periodicals, Inc.
Velocity‐selective magnetization‐prepared non‐contrast‐enhanced cerebral MR angiography at 3 Tesla: Improved immunity to B0/B1 inhomogeneity
Authors: Qin Qin , Shin Taehoon , Schär Michael , Guo Hua , Chen Hanwei , Qiao Ye 
Published: May 2015

PurposeTo develop a Fourier‐transform based velocity‐selective (VS) pulse train that offers improved robustness to B0/B1 inhomogeneity for non‐contrast‐enhanced cerebral MR angiography (MRA) at 3 Tesla (T).MethodsVS pulse train I and II with different saturation bands are proposed to incorporate paired and phase cycled refocusing pulses. Their sensitivity to B0/B1 inhomogeneity was estimated through simulation and compared with a single refocused VS pulse train. The implementation was compared to standard time of flight (TOF) among eight healthy subjects.ResultsIn contrast to single refocused VS pulse train, the simulated VS profiles from proposed pulse trains indicate much improved immunity to field inhomogeneity in the brain at 3T. Successive application of two identical VS pulse trains yields a better suppression of static tissue at the cost of 20∼30% signal loss within large vessels. Average relative contrast ratios of major cerebral arterial segments applying both pulse train I and II with two preparations are 0.81 ± 0.06 and 0.81 ± 0.05, respectively, significantly higher than 0.67 ± 0.07 of TOF‐MRA. VS MRA, in particular, the pulse train II with the narrower saturation band, depicts more small vessels with slower flow.ConclusionVS magnetization‐prepared cerebral MRA was demonstrated among normal subjects on a 3T scanner. Magn Reson Med 75:1232–1241, 2016. © 2015 Wiley Periodicals, Inc.