bluuebunny/crossref_metadata_2025 huggingface dataset:
Symbiotic prokaryotic communities from different populations of the giant barrel sponge, Xestospongia muta
Authors: Fiore Cara L. , Jarett Jessica K. , Lesser Michael P.
Published: October 2013

The prokaryotic community composition of the ecologically dominant sponge, Xestospongia muta, and the variability of this community across in different populations of sponges from the Caribbean and Bahamas were quantified using 454 pyrosequencing of the 16S rRNA gene. The symbiotic prokaryotic communities of X. muta were significantly different than the surrounding bacterioplankton communities while an analysis of similarity (ANOSIM) of the sponge prokaryotic symbionts from three geographically distant sites showed that both symbiont and bacterioplankton populations were significantly different between locations. Comparisons of individual sponges based on the UniFrac P‐test also revealed significant differences in community composition between individual sponges. The sponges harbored a variety of phylum level operational taxonomic units (OTUs) common to many sponges, including Cyanobacteria, Poribacteria, Acidobacteria, Chloroflexi, and Gemmatimonadetes, but four additional symbiotic phyla, previously not reported for this sponge, were observed. Additionally, a diverse archaeal community was also recovered from X. muta including sequences representing the phyla Euryarchaeota and Thaumarchaeota. These results have important ecological implications for the understanding of host–microbe associations, and provide a foundation for future studies addressing the functional roles these symbiotic prokaryotes have in the biology of the host sponge and the nutrient biogeochemistry of coral reefs.
Is essential tremor a Purkinjopathy? The role of the cerebellar cortex in its pathogenesis
Authors: Grimaldi Giuliana , Manto Mario
Published: October 2013

Essential tremor (ET) encompasses a group of progressive neurological diseases in which the primary clinical feature is kinetic tremor of the arms. There is accumulating evidence to suggest that the cerebellum is involved in the pathogenesis of ET; the clinical presentation, neurophysiological data, and functional and metabolic abnormalities revealed by neuroimaging studies all point toward the dysregulation of cerebellar circuits. Recent neuropathological findings at postmortem demonstrate that Purkinje neurons, and some brainstem neurons, play an integral role in the pathogenesis of this common neurological disorder. The assessment of Purkinje cell linear density shows that Purkinje density is abnormal in ET brains. Specific efforts need be devoted to understanding the molecular and cellular events occurring in the Purkinje neurons of the cerebellar cortex, which are emerging as being of particular importance in the pathogenesis of ET in a subgroup of patients. © 2013 International Parkinson and Movement Disorder Society.
Movement Disorder Society Unified Parkinson Disease Rating Scale experiences in daily living: Longitudinal changes and correlation with other assessments
Authors: Lang Anthony E. , Eberly Shirley , Goetz Christopher G. , Stebbins Glenn , Oakes David , Marek Ken , Ravina Bernard , Tanner Caroline M. , Shoulson Ira ,   on behalf of the LABS‐PD investigators
Published: October 2013

The Movement Disorder Society (MDS) commissioned a revision of the UPDRS with the goals of improving instructions and definitions, more accurately evaluating milder features, and assessing patient‐reported outcomes and nonmotor features. To date, no study has evaluated longitudinal changes in components of the MDS‐UPDRS over time or correlated these with changes in other scales of various symptoms. We assessed Parts I and II of the MDS‐UPDRS (non‐Motor and Motor Experiences of Daily Living [nM‐EDL, M‐EDL]) as well as a number of other scales of motor, cognitive and behavioral function in a large population of patients (n = 383) with early‐ to mid‐stage Parkinson's disease (PD) who had previously participated in a trial of a putative disease‐modifying agent. Both parts of a MDS‐UPDRS showed significant change over the 3‐year follow‐up period, with M‐EDL scores declining to a greater extent than nM‐EDL. Both the scores and their changes over time correlated relatively well with other rating scales of similar disease aspects. Modest correlations with the original version of the UPDRS supported the increased attention to nonmotor symptoms as well as milder levels of severity in the MDS‐UPDRS. The M‐EDL was much more sensitive to change over time in these early‐ to mid‐stage patients than the original UPDRS Activities of Daily Living (ADL) scale. Finally, we showed no change over time in a small group of individuals with dopamine transporter single‐photon emission computed tomography scans without evidence for dopamine deficiency. The nM‐EDL and M‐EDL components of the MDS‐UPDRS provide an effective, relevant measure of change in the broad spectrum of symptoms of PD over the first decade of the disease. © 2013 International Parkinson and Movement Disorder Society
Alexithymia—an independent risk factor for impulsive‐compulsive disorders in Parkinson's disease
Authors: Goerlich‐Dobre Katharina S. , Probst Catharina , Winter Lina , Witt Karsten , Deuschl Günther , Möller Bettina , van Eimeren Thilo
Published: October 2013

Impulsive‐compulsive disorders (ICDs) are frequent side effects of dopaminergic medication in Parkinson's disease (PD). Alexithymia, a personality trait characterized by difficulties identifying and describing feelings and an externally oriented thinking style, has been linked to various impulse‐control problems in the general population. In PD, the prevalence of alexithymia is approximately twice as high as in the general population. However, whether alexithymia is associated with ICDs in PD is currently unknown. We examined the relationship between self‐reported ICDs and alexithymia in a sample of 91 PD patients (89 on dopaminergic medication). Additional self‐report measures assessed impulsivity, depression, anxiety, behavioral inhibition/approach, and emotion‐regulation strategies. We observed that alexithymia, and particularly difficulty identifying feelings and difficulty describing feelings, was significantly correlated with ICDs, even when controlling for impulsivity, anxiety, and depression. In addition, a group analysis revealed that PD patients with clinical and moderate levels of alexithymia had significantly more ICDs than non‐alexithymic patients, suggesting that even moderately high alexithymia levels increase the risk for ICDs in PD. Our results identify alexithymia as an independent risk factor for ICDs in PD. Thus, the inclusion of alexithymia in the neuropsychiatric assessment of patients with PD may help identify patients at risk for ICDs. © 2013 International Parkinson and Movement Disorder Society
Clinical issues in the treatment of anxiety and depression in older adults with Parkinson's disease
Authors: Pachana Nancy A. , Egan Sarah J. , Laidlaw Ken , Dissanayaka Nadeeka , Byrne Gerard J. , Brockman Simone , Marsh Rodney , Starkstein Sergio
Published: October 2013

A significant proportion of persons affected by Parkinson's disease (PD) are over age 65 years. Mental health issues are often less a focus of treatment in this population than physical manifestations of the illness. Anxiety or depression alone, as well as comorbid depression and anxiety, are underrecognized in patients with PD and are associated with deleterious effects on physical and interpersonal functioning, negatively impacting quality of life and well‐being. We offer a brief overview of salient clinical points with respect to assessment and treatment approaches to enhance efficacy of the treatment of mental health symptoms in older adults with PD. Cognitive behavior therapy involves the patient learning to overcome behavioral avoidance associated with anxiety and challenge unhelpful negative cognitions. It is suggested that cognitive behavior therapy is an effective approach to treatment of anxiety and depression in PD and should be offered as a treatment to patients. © 2013 International Parkinson and Movement Disorder Society
The Role and Therapeutic Potential of Autophagy Modulation in Controlling Virus‐Induced Cell Death
Authors: Tovilovic Gordana , Ristic Biljana , Milenkovic Marina , Stanojevic Maja , Trajkovic Vladimir
Published: October 2013

Macroautophagy (hereafter referred to as autophagy) is an evolutionary conserved catabolic process in which the cytoplasmic content is sequestered and degraded by the lysosomal machinery in order to maintain cellular homeostasis or provide energy during metabolic and hypoxic stress. It also represents an important component of the host response against infectious agents, performing surveillance and effector functions involved in detection and clearance of pathogens, including viruses. Moreover, it appears that autophagy plays a major role in determining the fate of both virally infected and uninfected cells by blocking or promoting their death in a virus‐ and cell‐type‐dependent manner. We here review the current knowledge on the complex involvement of autophagy in survival and death of the host cells during viral infection, focusing on the molecular mechanisms underlying viral modulation of autophagic response and its interference with the cell death pathways. We also discuss a possible significance of the autophagy‐dependent modulation of cell death for the outcome and therapy of viral infections, emphasizing the need for a time‐ and cell‐type‐dependent fine‐tuning of the autophagic response in achieving an optimal balance between beneficial and adverse effects.
The Anticancer Properties of Salvia Miltiorrhiza Bunge (Danshen): A Systematic Review
Authors: Chen Xiuping , Guo Jiajie , Bao Jiaolin , Lu Jinjian , Wang Yitao
Published: October 2013

Salvia miltiorrhiza Bunge (Danshen in Chinese) is a classical Huoxue Huayu (a traditional Chinese medical term means promoting blood circulation and removing blood stasis) herb with 1000 years of clinical application. It mainly contains two groups of ingredients: the hydrophilic phenolic acids and the lipophilic tanshinones. Both groups have demonstrated multiple bioactivities, such as antioxidative stress, antiplatelet aggregation, anti‐inflammation, among others. Recent data have demonstrated that its lipophilic compounds, especially the tanshinones, show potent anticancer activities both in vitro and in vivo. The anticancer effects of the hydrophilic phenolic acids have also been reported. Furthermore, tanshinones provide structural skeletons for chemical modifications, allowing for a series of derivatives of interests. This review provides a systematic summary of the anticancer profile and the underlying mechanisms of the bioactive compounds isolated from Danshen with special emphasis on tanshinones, aiming to bring new insights for further research and development of this ancient herb.
Comparison of the flap survival with ischemic preconditioning on different pedicles under varied ischemic intervals in a rat bilateral pedicled flap model
Authors: Yildiz Kemalettin , Karsidag Semra , Akcal Arzu , Yesiloglu Nebil , Ugurlu Kemal , Ozagari Aysim , Guneren Ethem , Bas Lutfu
Published: October 2013

The study was undertaken to search whether pedicle selection for ischemic preconditioning (IP) and duration of global ischemia applied after IP influenced efficacy of IP on flap viability in epigastric adipocutaneous island flap with bilateral pedicles in rat model. In total, 159 rats were divided into one control and three (primary, secondary, or bilateral pedicle) IP treatment groups. IP was performed on different pedicles by three cycles of 10 minutes of pedicle clamping and 10 minutes of release. After IP procedure secondary pedicle was ligated in all groups, and flaps were exposed to 0, 1, 2, 4, or 6 hours of global ischemia by clamping primary pedicle. In control groups, after the perfusion of bipedicled flaps for 1 hour, left pedicle was ligated and flaps were exposed to global ischemia as in IP groups. On day 5 post‐surgery, tissue samples and topographic measurements were taken. No significant differences in semi‐quantitative scorings of polymorphonuclear leukocytes infiltration, chronic inflammation, interstitial edema, neovascularization, VEGF, and CD105 expression levels among groups were found (P > 0.05). Percentages of necrosis were consistently smaller in IP groups compared to controls for the same duration of global ischemia, with exception of the no‐ischemia. Area of necrosis was significantly smaller in primary IP group versus secondary IP group in the absence of global ischemia (P < 0.01). In the presence of global ischemia, both primary and secondary pedicle IP groups had significantly smaller percentage of necrosis than controls (P < 0.05) and there was no significant difference between primary and secondary IP groups (P > 0.05). Thus, IP performed on different pedicles may ameliorate flap survival in a comparable fashion, depending on the duration of global ischemia. Secondary pedicle IP was as effective as primary pedicle IP and may be feasible in free flap transfers. © 2013 Wiley Periodicals, Inc. Microsurgery 34:129–135, 2014.
Applicability Domain Dependent Predictive Uncertainty in QSAR Regressions
Authors: Sahlin U. , Jeliazkova N. , Öberg T.
Published: October 2013

Predictive models used in decision making, such as QSARs in chemical regulation or drug discovery, call for evaluated approaches to quantitatively assess associated uncertainty in predictions. Uncertainty in less reliable predictions may be captured by locally varying predictive errors. In the current study, model‐based bootstrapping was combined with analogy reasoning to generate predictive distributions varying in magnitude over a model’s domain of applicability. A resampling experiment based on PLS regressions on four QSAR data sets demonstrated that predictive errors assessed by k nearest neighbour or weighted PRedicted Error Sum of Squares (PRESS) on samples of external test data or by internal cross‐validation improved the performance of the uncertainty assessment. Analogy using similarity defined by Euclidean distances, or differences in standard deviation in perturbed predictions, resulted in better performances than similarity defined by distance to, or density of, the training data. Locally assessed predictive distributions had on average at least as good coverage as Gaussian distribution with variance assessed from the PRESS. An R‐code is provided that evaluates performances of the suggested algorithms to assess predictive error based on log likelihood scores and empirical coverage graphs, and which applies these to derive confidence intervals or samples from the predictive distributions of query compounds.
On the one‐dimensional relativistic induction equation
Authors: Núñez Manuel
Published: October 2013

The induction equation of relativistic magnetohydrodynamics is considered as a singular perturbation problem for small magnetic diffusivity. When the quantities depend on a single space variable, the resulting hyperbolic equation may be studied with techniques of asymptotic analysis. Different approximations are found for initial, intermediate, and large times. The last case is the most difficult; the approximate magnetic flux function satisfies a certain parabolic equation. This equation is studied from the viewpoint of energy dissipation, providing clues on the behavior of the electric and magnetic fields. Copyright © 2013 John Wiley & Sons, Ltd.
Positive solutions for systems of nonlinear second‐order multipoint boundary value problems
Authors: Henderson Johnny , Luca Rodica
Published: October 2013

We study the existence of positive solutions for systems of second‐order nonlinear ordinary differential equations, subject to multipoint boundary conditions. Copyright © 2013 John Wiley & Sons, Ltd.
Existence and asymptotic behavior of global smooth solution for p‐system with nonlinear damping and fixed boundary effect
Authors: Jiang Mina , Zhang Yinghui
Published: October 2013

This paper is concerned with the initial boundary value problem for the p‐system with nonlinear damping and fixed boundary condition. We show that the corresponding problem admits a unique global solution, and such a solution tends time asymptotically to the corresponding nonlinear diffusion wave governed by the classical Darcy's law provided that the corresponding prescribed initial error function is sufficiently small. Copyright © 2013 John Wiley & Sons, Ltd.
Effects of ovalbumin glycoconjugates on alleviation of orally induced egg allergy in mice via dendritic‐cell maturation and T‐cell activation
Authors: Rupa Prithy , Nakamura Soichiro , Katayama Shigeru , Mine Yoshinori
Published: October 2013

Scope

Glycation of allergens via Maillard reaction or chemical conjugation has been shown to influence susceptibility to food‐induced allergies. It is hypothesized that mucosal immune response bias can be favorably altered by orally administering various forms of glycated ovalbumin (OVA).

Methods and results

Groups of Balb/c mice (n = 10) were orally sensitized to OVA and administered various forms of glycated OVA (glucose, mannose, glucomannan, galactomannan, and a mixture containing OVA and glucomannan). Outcomes post oral challenge were measured as clinical allergic signs, serum histamine, mouse mast cell protease 1 (MMCP‐1), antibody activity, type‐1/2 cytokines, percentage of T‐regulatory cells (T‐regs) and in vitro dendritic cell, and T‐cell‐related mechanisms. Clinical signs and specific IgE were decreased (p ≤ 0.05), and T‐reg cell percentage was increased in the mannose and glucomannan treated groups. The OVA‐mannose group also had less histamine, MMCP‐1, specific IgG, IL‐4 and IL‐17, and more IL‐12p70 (p ≤ 0.05). Other parameters measured did not differ significantly among groups. Also, OVA‐glycated mannose reduced maturation and uptake by dendritic cells. Less activation of T cells and type‐2 cytokine response in DC–T‐cell cocultures were observed with OVA‐glycated mannose stimulation.

Conclusion

This study validates, for the first time, the use of OVA‐glycated mannose and glucomannan for potential beneficial dietary interventions for allergy.
β‐Cryptoxanthin uptake in THP‐1 macrophages upregulates the CYP27A1 signaling pathway
Authors: Fu Hongfei , Wu Canjie , Riaz Hasan , Zhang Hualin , Han Li , Bai Liya , Yang Feifei , Yang Liguo
Published: October 2013

Scope

Mitochondrial sterol 27‐hydroxylase (CYP27A1), a mediator of cholesterol homeostasis, is reported to exhibit antiatherogenic properties. Many studies suggested that all‐trans retinoic acid can be used to treat atherosclerosis through retinoic acid receptor (RAR)‐mediated upregulation of CYP27A1 expression. In this study, we hypothesized that β‐cryptoxanthin (β‐cry), as a natural ligand of RAR, might act as antiatherogenic agent by upregulating CYP27A1.

Methods and results

We found that β‐cry treatment significantly upregulated genes involved in the uptake, transport, and metabolism of retinoids and the signaling pathway of CYP27A1 expression in THP‐1 macrophages as detected by microarray analysis. Meanwhile, intracellular levels of β‐cry were correlated to the concentration and exposure time of the treatment. The expression of genes, involved in signaling pathway of CYP27A1, was dramatically decreased due to repressed activity of RAR. Higher level of 27‐hydroxycholesterol was detected in β‐cry‐treated macrophages by HPLC. Docking simulation showed that β‐cry could interact with cellular retinoic acid binding protein 2. These findings were further confirmed through microarray results.

Conclusion

Our results provide strong evidence that β‐cry can be actively taken up by THP‐1 macrophages and exhibits antiatherogenic effect on THP‐1 macrophages by inducing CYP27A1 expression via RAR.
Immunological behavior of in vitro digested egg‐white lysozyme
Authors: Jiménez‐Saiz Rodrigo , Benedé Sara , Miralles Beatriz , López‐Expósito Iván , Molina Elena , López‐Fandiño Rosina
Published: October 2013

Scope

Besides its antimicrobial properties, lysozyme (LYS) is one of the major allergens from hen egg. This paper addresses the identification of the peptides produced upon in vitro gastrointestinal digestion of LYS, together with their IgE‐binding and biological activity as a contribution to the understanding of what makes it a relevant allergen.

Methods and results

Simulated in vitro gastrointestinal digestion together with IgE binding, basophil degranulation, and peripheral blood mononuclear cells stimulation experiments were carried out. Identification of the fragments released was performed by HPLC‐MS/MS and the immunoreactive products were analyzed by MALDI‐TOF/TOF. Results showed that in vitro gastric and gastroduodenal digests of LYS maintained IgE binding, basophil activation capacity, and preserved T‐cell immunogenicity. These biological activities could be attributed to either the persistence of intact LYS, due to incomplete gastric degradation and subsequent duodenal precipitation, the formation of fragment f(24–129) by chymotrypsin action on the soluble intact protein, or the release, upon combined gastric and pancreatic digestion, of immunoreactive peptides linked by disulphide bonds containing the epitopes f(57–83) and f(108–122).

Conclusion

The pH of gastric hydrolysis greatly determined the extent of subsequent duodenal digestion of LYS and the disclosure of relevant epitopes that could increase its allergenic potential.
Induced pluripotent stem cells from goat fibroblasts
Authors: Song Hui , Li Hui , Huang Mingrui , Xu Dan , Gu Chenghao , Wang Ziyu , Dong Fulu , Wang Feng
Published: October 2013

Embryonic stem cells (ESCs) are a powerful model for genetic engineering, studying developmental biology, and modeling disease. To date, ESCs have been established from the mouse (Evans and Kaufman, 1981, Nature 292:154–156), non‐human primates (Thomson et al., , Proc Nat Acad Sci USA 92:7844–7848), humans (Thomson et al., 1998, Science 282:1145–1147), and rats (Buehr et al., , Cell 135:1287–1298); however, the derivation of ESCs from domesticated ungulates such as goats, sheep, cattle, and pigs have not been successful. Alternatively, induced pluripotent stem cells (iPSCs) can be generated by reprogramming somatic cells with several combinations of genes encoding transcription factors (OCT3/4, SOX2, KLF4, cMYC, LIN28, and NANOG). To date, iPSCs have been isolated from various species, but only limited information is available regarding goat iPSCs (Ren et al., 2011, Cell Res 21:849–853). The objectives of this study were to generate goat iPSCs from fetal goat primary ear fibroblasts using lentiviral transduction of four human transcription factors: OCT4, SOX2, KLF4, and cMYC. The goat iPSCs were successfully generated by co‐culture with mitomycin C‐treated mouse embryonic fibroblasts using medium supplemented with knockout serum replacement and human basic fibroblast growth factor. The goat iPSCs colonies are flat, compact, and closely resemble human iPSCs. They have a normal karyotype; stain positive for alkaline phosphatase, OCT4, and NANOG; express endogenous pluripotency genes (OCT4, SOX2, cMYC, and NANOG); and can spontaneously differentiate into three germ layers in vitro and in vivo. Mol. Reprod. Dev. 80: 1009–1017, 2013. © 2013 Wiley Periodicals, Inc.
Rapamycin‐sensitive mTORC1 signaling is involved in physiological primordial follicle activation in mouse ovary
Authors: Tong Yuanyuan , Li Fei , Lu Yi , Cao Yanlan , Gao Jimin , Liu Jianghuai
Published: October 2013

In mammals, resting female oocytes reside in primordial ovarian follicles. An individual primordial follicle may stay quiescent for a protracted period of time before initiating follicular growth, which is also termed “activation.” Female reproductive capacity is sustained by the gradual, streamlined activation of the entire population of primordial follicles, but this process also results in reproductive senescence in older animals. Based on the recent findings that genetically triggered, excessive mammalian target of rapamycin complex 1 (mTORC1) activation in mouse oocytes leads to accelerated primordial follicle activation, we examined the necessity of mTORC1 signaling in physiological primordial follicle activation. We found that induction of oocyte mTORC1 activity is associated with early follicular growth in neonatal mouse ovaries. Pharmacological inhibition of mTORC1 activity in vivo by rapamycin treatment leads to a marked, but partial, suppression of primordial follicle activation. The suppressive effect of rapamycin on primordial follicle activation was reproduced in cultured ovaries. While rapamycin did not apparently affect several plausible cellular targets in neonatal mouse ovaries, such as mTORC2, AKT, or cyclin‐dependent kinase (CDK) inhibitor p27‐KIP1, its inhibitory effect on Cyclin A2 gene expression implies that mTORC1 signaling in oocytes may engage a Cyclin A/CDK regulatory network that promotes primordial follicle activation. The current work strengthens the concept that mTORC1‐dependent events in the oocytes of primordial follicles may represent potential targets for intervention in humans to slow the depletion of the ovarian reserve. Mol. Reprod. Dev. 80: 1018–1034, 2013. © 2013 Wiley Periodicals, Inc.
Influence of Acrylated Lactide‐Caprolactone Macromonomers on the Performance of High Biomass Content Pressure‐Sensitive Adhesives
Authors: Pu Gang , Hauge Drew A. , Gu Cheng , Zhang Jilin , Severtson Steven J. , Wang Wenjun , Houtman Carl J.
Published: October 2013

Results from a study of the influence of macromonomer (MM) composition on the properties of high‐biomass content adhesive polymers are reported. Pressure‐sensitive adhesives (PSAs) are synthesized through miniemulsion polymerization of n‐butyl acrylate, vinyl acetate, and methacrylic acid with lactide‐containing MMs. The MMs are generated from bulk ring‐opening polymerizations of lactide and ϵ‐caprolactone with 2‐hydroxyethyl methacrylate. Both meso‐lactide and L‐lactide were used to produce MMs of various chain lengths and compositions. It was found that properties of generated polymers show a strong dependency both on the content and type of lactide utilized. Standard adhesive tests run on the PSAs demonstrate that MM composition can be used to provide significant control over perfromance properties.
Cardiac R2* values are independent of the image analysis approach employed
Authors: Meloni Antonella , Rienhoff Hugh Young , Jones Amber , Pepe Alessia , Lombardi Massimo , Wood John C.
Published: October 2013

Purpose

To determine whether systematic differences were present between myocardial R2* values obtained with two different decay models: truncation and exponential + constant (Exp‐C).

Methods

Single‐center cohorts were used to compare black and bright blood sequences separately, and a multicenter cohort of mixed bright and black blood studies was used to assess the generalizability. Truncated exponential estimates were calculated with CMRtools, which uses a single region of interest (ROI) method. Exp‐C estimates were calculated using a pixelwise approach.

Results

No differences could be distinguished based upon whether a white or black blood sequence was examined. The two fitting algorithms yielded similar R2* values, with R‐squared values exceeding 0.997 and a coefficient of variation of 3% to 4%. Results using the pixelwise method yielded a small systematic bias (∼3%) that became apparent in patients with severe iron deposition. This disparity disappeared when Exp‐C fitting was used on a single ROI, suggesting that the use of pixelwise mapping was responsible for the bias. In the multicenter cohort, the strong agreement between the two fitting approaches was reconfirmed.

Conclusion

Cardiac R2* values are independent of the signal model used for its calculation over clinically relevant ranges. Clinicians can compare results among centers using these disparate approaches with confidence. Magn Reson Med 72:485–491, 2014. © 2013 Wiley Periodicals, Inc.
On the confounding effect of temperature on chemical shift‐encoded fat quantification
Authors: Hernando Diego , Sharma Samir D. , Kramer Harald , Reeder Scott B.
Published: October 2013

Purpose

To characterize the confounding effect of temperature on chemical shift‐encoded (CSE) fat quantification.

Methods

The proton resonance frequency of water, unlike triglycerides, depends on temperature. This leads to a temperature dependence of the spectral models of fat (relative to water) that are commonly used by CSE‐MRI methods. Simulation analysis was performed for 1.5 Tesla CSE fat–water signals at various temperatures and echo time combinations. Oil–water phantoms were constructed and scanned at temperatures between 0 and 40°C using spectroscopy and CSE imaging at three echo time combinations. An explanted human liver, rejected for transplantation due to steatosis, was scanned using spectroscopy and CSE imaging. Fat–water reconstructions were performed using four different techniques: magnitude and complex fitting, with standard or temperature‐corrected signal modeling.

Results

In all experiments, magnitude fitting with standard signal modeling resulted in large fat quantification errors. Errors were largest for echo time combinations near TEinit ≈ 1.3 ms, ΔTE ≈ 2.2 ms. Errors in fat quantification caused by temperature‐related frequency shifts were smaller with complex fitting, and were avoided using a temperature‐corrected signal model.

Conclusion

Temperature is a confounding factor for fat quantification. If not accounted for, it can result in large errors in fat quantifications in phantom and ex vivo acquisitions. Magn Reson Med 72:464–470, 2014. © 2013 Wiley Periodicals, Inc.
Noninvasive imaging of infection after treatment with tumor‐homing bacteria using Chemical Exchange Saturation Transfer (CEST) MRI
Authors: Liu Guanshu , Bettegowda Chetan , Qiao Yuan , Staedtke Verena , Chan Kannie W.Y. , Bai Renyuan , Li Yuguo , Riggins Gregory J. , Kinzler Kenneth W. , Bulte Jeff W.M. , McMahon Michael T. , Gilad Assaf A. , Vogelstein Bert , Zhou Shibin , van Zijl Peter C.M.
Published: October 2013

Purpose

To develop a noninvasive MRI method for determining the germination and infection of tumor‐homing bacteria in bacteriolytic cancer therapy using endogenous CEST contrast.

Methods

The CEST parameters of the anaerobic gram‐positive bacterium Clostridium novyi‐NT (C. novyi‐NT) were first characterized in vitro, then used to detect C. novyi‐NT germination and infection in subcutaneous CT26 colorectal tumor‐bearing mice (n = 6) after injection of 300 million bacterial spores. Lipopolysacharide (LPS) injected mice were used to exclude that the changes of CEST MRI were due to inflammation.

Results

CEST contrast was observed over a broad frequency range for bacterial suspensions in vitro, with the maximum contrast around 2.6 ppm from the water resonance. No signal could be detected for bacterial spores, demonstrating the specificity for germination. In vivo, a significant elevation of CEST contrast was identified in C. novyi‐NT infected tumors as compared to those before bacterial germination and infection (P < 0.05; n = 6). No significant change was observed in tumors with LPS‐induced sterile inflammation (P > 0.05; n = 4).

Conclusion

Endogenous bacterial CEST contrast (bacCEST) can be used to monitor the germination and proliferation of the therapeutic bacterium C. novyi‐NT without a need for exogenous cell labeling probes. Magn Reson Med 70:1690–1698, 2013. © 2013 Wiley Periodicals, Inc.
Apparent exchange rate imaging in anisotropic systems
Authors: Sønderby Casper K. , Lundell Henrik M. , Søgaard Lise V. , Dyrby Tim B.
Published: October 2013

Purpose

Double‐wave diffusion experiments offer the possibility of probing correlation between molecular diffusion at multiple time points. It has recently been shown that this technique is capable of measuring the exchange of water across cellular membranes. The aim of this study was to investigate the effect of macroscopic tissue anisotropy on the measurement of the apparent exchange rate (AXR) in multicompartment systems.

Methods

AXR data were collected from yeast and perfusion‐fixated brain tissue at high angular resolution on a preclinical imaging system. The AXR was expanded for anisotropic systems by calculating scalar AXR values along the principal directions of the diffusion tensor.

Results

In yeast, both the AXR and diffusivity were rotational invariant, whereas in fixated brain tissue, the measured AXR was sensitive to the orientation of anisotropic structures. AXR, especially in white matter, was robustly estimated along the first and second principal directions of the diffusion tensor, but increasing noise was seen in the AXR estimates along the third principal direction of the diffusion tensor.

Conclusion

Our results indicate that tissue anisotropy must be considered for AXR estimates in complex biological systems. Magn Reson Med 72:756–762, 2014. © 2013 Wiley Periodicals, Inc.
Improved quantification of myocardial blood flow using highly constrained back projection reconstruction
Authors: Chen David , Sharif Behzad , Dharmakumar Rohan , Thomson Louise E.J. , Bairey Merz C. Noel , Berman Daniel S. , Li Debiao
Published: October 2013

Purpose

To improve quantification of myocardial blood flow using a fast T1 mapping technique using highly constrained back projection reconstruction (HYPR)‐accelerated acquisition.

Methods

A major source of error in the measurement of myocardial blood flow (MBF) using MRI is the nonlinear relationship between image signal intensity and contrast agent (CA) concentration. HYPR‐accelerated radial acquisition was used to generate pixel‐wise T1 maps with a temporal resolution of one heartbeat. HYPR produces images with a temporal footprint of 40 ms and four images within 188 ms. T1 values were converted into CA concentrations by the known linear relationship between CA concentration and T1. The T1 mapping technique was used to quantify MBF in 10 healthy subjects and compared with MBF found using image signal intensity as well as MBF reported in the literature.

Results

The MBF measured using the proposed method was more consistent with that previously reported in the literature and was significantly lower (P = 0.002) than that calculated using image signal intensity (1.11 ± 0.27 mL/min/g versus 1.88 ± 0.45 mL/min/g, respectively).

Conclusion

We developed a fast T1 mapping method for MBF quantification using radial sampling and HYPR. Further validation is required to determine its clinical value in assessing myocardial perfusion deficit in coronary artery disease. Magn Reson Med 72:749–755, 2014. © 2013 Wiley Periodicals, Inc.
Viscous energy loss in the presence of abnormal aortic flow
Authors: Barker Alex J. , van Ooij Pim , Bandi Krishna , Garcia Julio , Albaghdadi Mazen , McCarthy Patrick , Bonow Robert O. , Carr James , Collins Jeremy , Malaisrie S. Chris , Markl Michael
Published: October 2013

Purpose

To present a theoretical basis for noninvasively characterizing in vivo fluid‐mechanical energy losses and to apply it in a pilot study of patients known to express abnormal aortic flow patterns.

Methods

Four‐dimensional flow MRI was used to characterize laminar viscous energy losses in the aorta of normal controls (n = 12, age = 37 ± 10 yr), patients with aortic dilation (n = 16, age = 52 ± 8 yr), and patients with aortic valve stenosis matched for age and aortic size (n = 14, age = 46 ± 15 yr), using a relationship between the three‐dimensional velocity field and viscous energy dissipation.

Results

Viscous energy loss was elevated significantly in the thoracic aorta in patients with dilated aorta (3.6 ± 1.3 mW, P = 0.024) and patients with aortic stenosis (14.3 ± 8.2 mW, P < 0.001) compared with healthy volunteers (2.3 ± 0.9 mW). The same pattern of significant differences was seen in the ascending aorta, where viscous energy losses in patients with dilated aortas (2.2 ± 1.1 mW, P = 0.021) and patients with aortic stenosis (10.9 ± 6.8 mW, P < 0.001) were elevated compared with healthy volunteers (1.2 ± 0.6 mW).

Conclusion

This technique provides a capability to quantify the contribution of abnormal laminar blood flow to increased ventricular afterload. In this pilot study, viscous energy loss in patient cohorts was significantly elevated and indicates that cardiac afterload is increased due to abnormal flow. Magn Reson Med 72:620–628, 2014. © 2013 Wiley Periodicals, Inc.
Localized spatio‐temporal constraints for accelerated CMR perfusion
Authors: Akçakaya Mehmet , Basha Tamer A. , Pflugi Silvio , Foppa Murilo , Kissinger Kraig V. , Hauser Thomas H. , Nezafat Reza
Published: October 2013

Purpose

To develop and evaluate an image reconstruction technique for cardiac MRI (CMR) perfusion that uses localized spatio‐temporal constraints.

Methods

CMR perfusion plays an important role in detecting myocardial ischemia in patients with coronary artery disease. Breath‐hold k‐t–based image acceleration techniques are typically used in CMR perfusion for superior spatial/temporal resolution and improved coverage. In this study, we propose a novel compressed sensing‐based image reconstruction technique for CMR perfusion, with applicability to free‐breathing examinations. This technique uses local spatio‐temporal constraints by regularizing image patches across a small number of dynamics. The technique was compared with conventional dynamic‐by‐dynamic reconstruction, and sparsity regularization using a temporal principal‐component (pc) basis, as well as zero‐filled data in multislice two‐dimensional (2D) and three‐dimensional (3D) CMR perfusion. Qualitative image scores were used (1 = poor, 4 = excellent) to evaluate the technique in 3D perfusion in 10 patients and five healthy subjects. On four healthy subjects, the proposed technique was also compared with a breath‐hold multislice 2D acquisition with parallel imaging in terms of signal intensity curves.

Results

The proposed technique produced images that were superior in terms of spatial and temporal blurring compared with the other techniques, even in free‐breathing datasets. The image scores indicated a significant improvement compared with other techniques in 3D perfusion (x‐pc regularization, 2.8 ± 0.5 versus 2.3 ± 0.5; dynamic‐by‐dynamic, 1.7 ± 0.5; zero‐filled, 1.1 ± 0.2). Signal intensity curves indicate similar dynamics of uptake between the proposed method with 3D acquisition and the breath‐hold multislice 2D acquisition with parallel imaging.

Conclusion

The proposed reconstruction uses sparsity regularization based on localized information in both spatial and temporal domains for highly accelerated CMR perfusion with potential use in free‐breathing 3D acquisitions. Magn Reson Med 72:629–639, 2014. © 2013 Wiley Periodicals, Inc.
Leg muscle function and fatigue during walking in spinal muscular atrophy type 3
Authors: Montes Jacqueline , Dunaway Sally , Garber Carol Ewing , Chiriboga Claudia A. , De Vivo Darryl C. , Rao Ashwini K.
Published: October 2013

Introduction: Spinal muscular atrophy (SMA) causes muscle weakness and fatigue. Better understanding of the relationship between weakness and fatigue may help identify potential targets for rehabilitation. Methods: Gait and surface electromyography (EMG) from 4 muscle groups were measured during the Six‐Minute Walk Test (6MWT) in 10 ambulatory participants, aged 9–49 years. Average root mean square amplitude (RMS) of muscle activity was calculated. Strength was assessed using manual and quantitative methods. Results: RMS, stride length, and velocity decreased during the 6MWT. Knee flexor and hip abductor strength was associated with fatigue‐related changes; overall strength correlated with disease duration; and leg strength was associated with 6MWT distance. Conclusions: Clinical measures are valid in assessing fatigue and function in SMA, and these assessments can be enhanced by use of gait analysis and EMG. Disease duration and strength measures may represent further stratification refinements when enrolling patients in clinical trials. Muscle Nerve 50: 34–39, 2014
Anconeus motor unit number estimates using decomposition‐based quantitative electromyography
Authors: Stevens Daniel E.S. , Harwood Brad , Power Geoffrey A. , Doherty Timothy J. , Rice Charles L.
Published: October 2013

Introduction: Motor unit number estimates (MUNEs) provide important information in health, aging, and disease, and can be determined using decomposition‐enhanced spike‐triggered averaging (DE‐STA). Discrimination of surface‐detected motor unit potentials (S‐MUPs) has been limited to contractile forces of ∽30% maximum voluntary contraction (MVC), which is insufficient to recruit a representative sample of the entire MU pool in most muscles. Unique features of the anconeus may permit MUNEs at high muscle activation levels. Methods: In 10 men (25 ± 3 years), anconeus MUNEs were performed using DE‐STA at 10%, 30%, and 50% root‐mean‐square of MVC (RMSMVC). Results: The mean compound muscle action potential of the anconeus was ∽6 mV, and average S‐MUP amplitudes were ∽100 μV, 145 μV, and 235 μV at 10%, 30%, and 50% RMSMVC, resulting in low average MUNEs of 58, 38, and 25, respectively. Conclusions: Elbow extensor force–EMG relationships suggest full recruitment of the anconeus MU pool at 50% RMSMVC, thus providing a representative sample for MUNE. Muscle Nerve 50: 52–59, 2014
Activity rating scales in adult muscle disease: What do they actually measure?
Authors: Seedat Farah , James Meredith K. , Rose Michael R.
Published: October 2013

Introduction: There is a diversity of rating scales that assess function in muscle disease. Definitive knowledge of the content covered by these scales would help in making choices. Methods: We searched for activity rating scales used for muscle disease and assessed their content by linking scale items to the International Classification of Functioning, Disability and Health (ICF) and the muscle regions they cover. Results: Of the 119 scales found, 19 muscle disease–specific and 9 generic scales were prioritized for analysis. These 28 scales contained 457 items, from which 1145 concepts were identified and 160 were unique. Of these concepts, 97.8% could be linked to the ICF, most to the activities and participation domain (68.7%), followed by environmental factors (22.5%) and body functions (6.6%). Global muscle function was assessed most frequently, followed by lower and upper extremity function. Conclusions: This content comparison should allow for a better‐informed choice of activity rating scales for muscle disease. Muscle Nerve 50: 14–23, 2014
ROLE of exercise in maintaining the integrity of the neuromuscular junction
Authors: Nishimune Hiroshi , Stanford John A. , Mori Yasuo
Published: October 2013

Physical activity plays an important role in preventing chronic disease in adults and the elderly. Exercise has beneficial effects on the nervous system, including at the neuromuscular junction (NMJ). Exercise causes hypertrophy of NMJs and improves recovery from peripheral nerve injuries, whereas decreased physical activity causes degenerative changes in NMJs. Recent studies have begun to elucidate molecular mechanisms underlying the beneficial effects of exercise. These mechanisms involve Bassoon, neuregulin‐1, peroxisome proliferator–activated receptor gamma coactivator 1α, insulin‐like growth factor‐1, glial cell line–derived neurotrophic factor, neurotrophin 4, Homer, and nuclear factor of activated T cells c1. For example, NMJ denervation and active zone decreases have been observed in aged NMJs, but these age‐dependent degenerative changes can be ameliorated by exercise. In this review we assess the effects of exercise on the maintenance and regeneration of NMJs and highlight recent insights into the molecular mechanisms underlying these exercise effects. Muscle Nerve 49:315–324, 2014
Discrete element modelling of material non‐coaxiality in simple shear flows
Authors: Ai Jun , Langston Paul A. , Yu Hai‐Sui
Published: October 2013

We investigate the quasi‐static simple shear flow of a two‐dimensional assembly of cohesionless particles using discrete element method (DEM) simulations. We focus on the unsteady flow regime where the solid would experience significant evolution of stresses, mobilised shear strength and dilation. We construct the DEM model using a discretised‐wall confined granular cell where the apparent boundary is allowed to dilate or contract synchronously with the confined solid. A rather uniform simple shear field is achieved across the whole assembly, which benefits rheological studies in generalising constitutive laws for continuum methods. We examine two aspects of the simple shear behaviour: macroscopic stress and strain rate evolution, particularly the non‐coaxiality between the principal directions of the two; and micromechanics such as evolution of fabric. For an initially anisotropic specimen sheared under constant normal pressure, the direction of principal stress rotates towards that of the principal strain rate, gradually reducing the degree of non‐coaxiality from about 45° to fluctuating around 0°. The rate in approaching coaxiality is slower in samples with larger initial porosity, stress ratio and mean stress. Generally, a faster rate in approaching coaxiality in simple shear is observed in a more dilatant sample, which often shows a larger degree of mobilised fabric anisotropy, suggesting the possible important role of instantaneous internal friction angle. The evolution of principal fabric direction resembles that of the principal stress direction. © 2013 The Authors. International Journal for Numerical and Analytical Methods in Geomechanics published by John Wiley & Sons, Ltd.
Cannabinoids and the endocannabinoid system in lower urinary tract function and dysfunction
Authors: Hedlund Petter
Published: October 2013

Aims

To review knowledge on cannabinoids and the endocannabinoid system in lower urinary tract function and dysfunction.

Methods

Review of MEDLINE using defined search terms, and manual analysis. Articles published in English were included.

Results and Discussion

Components of the endocannabinoid system—cannabinoid (CB) receptor types 1 and 2, anandamide, and fatty acid amide hydrolase (FAAH), which degrades anandamide and related fatty‐acid amides—have been located to lower urinary tract tissues of mice, rats, monkeys, and humans. Studies have located CB receptors in urothelium and sensory nerves and FAAH in the urothelium. CB receptor‐ and FAAH‐related activities have also been reported in the lumbosacral spinal cord. Data on supraspinal CB functions in relation to micturition are lacking.

Cannabinoids are reported to reduce sensory activity of isolated tissues, cause antihyperalgesia in animal studies of bladder inflammation, affect urodynamics parameters reflecting sensory functions in animals models, and appear to have effects on storage symptoms in humans. FAAH inhibitors have affected sensory bladder functions and reduced bladder overactivity in rat models. Cannabinoids may modify nerve‐mediated functions of isolated lower urinary tract tissues.

Conclusions

Evidence suggests components of the endocannabinoid system are involved in regulation of bladder function, possibly at several levels of the micturition pathway. It is unclear if either CB receptor has a dominant role in modification of sensory signals or if differences exist at peripheral and central nervous sites. Amplification of endocannabinoid activity by FAAH inhibitors may be an attractive drug target in specific pathways involved in LUTS. Neurourol. Urodynam. 33:46–53, 2014. © 2013 Wiley Periodicals, Inc.