bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential methylation of the micro‐RNA 7b gene targets postnatal maturation of murine neuronal Mecp2 gene expression
Authors: Chen Yongjun , Shin Bo‐Chul , Thamotharan Shanthie , Devaskar Sherin U.
Published: September 2013

DNA methylation and microRNAs (miRNAs) play crucial roles in maturation of postnatal mouse neurons. Aberrant DNA methylation and/or altered miRNA expression cause postnatal neurodevelopmental disorders. In general, DNA methylation in the 5′‐flanking region suppresses gene expression through recruitment of methyl‐CpG binding domain proteins (MBPs) to the cytosine residues of CpG dinucleotides. X‐linked MeCP2 (methyl‐CpG binding protein 2), a member of MBPs, is a methylation‐associated transcriptional repressor with other functions in the central nervous system (CNS). miRNAs negatively regulate gene expression by targeting the 3′‐untranslated region (3′UTR). Some miRNA genes harboring or being embedded in CpG islands undergo methylation‐mediated silencing. One such miRNA is miR‐7b which is differentially expressed through stages of neurodevelopment. In our present study, we focused on a canonical CpG island located in the 5′‐flanking region of the murine miR‐7b gene. Hypermethylation of this CpG island down‐regulates miR‐7b while recruiting MeCP2 to the methylated CpG dinucleotides. Meanwhile, Mecp2, a target of miR‐7b, was up‐regulated due to lack of restrain exerted by miR‐7b during maturation of postnatal (PN) mouse neurons between PN3 and PN14. Our results indicate that miR‐7b is a direct downstream gene transcriptional target while also being a negative post‐transcriptional regulator of Mecp2 expression. We speculate that this bidirectional feed‐back autoregulatory function of miR‐7b and Mecp2 while linking DNA methylation and miRNA action maintains the homeostatic control of gene expression necessary during postnatal maturation of mammalian neurons. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 74: 407–425, 2014
Therapeutic potential of cannabinoid medicines
Authors: Robson P. J.
Published: September 2013

Cannabis was extensively used as a medicine throughout the developed world in the nineteenth century but went into decline early in the twentieth century ahead of its emergence as the most widely used illicit recreational drug later that century. Recent advances in cannabinoid pharmacology alongside the discovery of the endocannabinoid system (ECS) have re‐ignited interest in cannabis‐based medicines. The ECS has emerged as an important physiological system and plausible target for new medicines. Its receptors and endogenous ligands play a vital modulatory role in diverse functions including immune response, food intake, cognition, emotion, perception, behavioural reinforcement, motor co‐ordination, body temperature, wake/sleep cycle, bone formation and resorption, and various aspects of hormonal control. In disease it may act as part of the physiological response or as a component of the underlying pathology. In the forefront of clinical research are the cannabinoids delta‐9‐tetrahydrocannabinol and cannabidiol, and their contrasting pharmacology will be briefly outlined. The therapeutic potential and possible risks of drugs that inhibit the ECS will also be considered. This paper will then go on to review clinical research exploring the potential of cannabinoid medicines in the following indications: symptomatic relief in multiple sclerosis, chronic neuropathic pain, intractable nausea and vomiting, loss of appetite and weight in the context of cancer or AIDS, psychosis, epilepsy, addiction, and metabolic disorders. Copyright © 2013 John Wiley & Sons, Ltd.
Elevated CO2 affects embryonic development and larval phototaxis in a temperate marine fish
Authors: Forsgren Elisabet , Dupont Sam , Jutfelt Fredrik , Amundsen Trond
Published: September 2013

As an effect of anthropogenic CO2 emissions, the chemistry of the world's oceans is changing. Understanding how this will affect marine organisms and ecosystems are critical in predicting the impacts of this ongoing ocean acidification. Work on coral reef fishes has revealed dramatic effects of elevated oceanic CO2 on sensory responses and behavior. Such effects may be widespread but have almost exclusively been tested on tropical reef fishes. Here we test the effects elevated CO2 has on the reproduction and early life history stages of a temperate coastal goby with paternal care by allowing goby pairs to reproduce naturally in an aquarium with either elevated (ca 1400 μatm) CO2 or control seawater (ca 370 μatm CO2). Elevated CO2 did not affect the occurrence of spawning nor clutch size, but increased embryonic abnormalities and egg loss. Moreover, we found that elevated CO2 significantly affected the phototactic response of newly hatched larvae. Phototaxis is a vision‐related fundamental behavior of many marine fishes, but has never before been tested in the context of ocean acidification. Our findings suggest that ocean acidification affects embryonic development and sensory responses in temperate fishes, with potentially important implications for fish recruitment.
Why to account for finite sites in population genetic studies and how to do this with Jaatha 2.0
Authors: Mathew Lisha A. , Staab Paul R. , Rose Laura E. , Metzler Dirk
Published: September 2013

With the advent of next‐generation sequencing technologies, large data sets of several thousand loci from multiple conspecific individuals are available. Such data sets should make it possible to obtain accurate estimates of population genetic parameters, even for complex models of population history. In the analyses of large data sets, it is difficult to consider finite‐sites mutation models (FSMs). Here, we use extensive simulations to demonstrate that the inclusion of FSMs is necessary to avoid severe biases in the estimation of the population mutation rate θ, population divergence times, and migration rates. We present a new version of Jaatha, an efficient composite‐likelihood method for estimating demographic parameters from population genetic data and evaluate the usefulness of Jaatha in two biological examples. For the first application, we infer the speciation process of two wild tomato species, Solanum chilense and Solanum peruvianum. In our second application example, we demonstrate that Jaatha is readily applicable to NGS data by analyzing genome‐wide data from two southern European populations of Arabidopsis thaliana. Jaatha is now freely available as an R package from the Comprehensive R Archive Network (CRAN).
The case of arsenic contamination in the Sardinian Geopark, Italy, analyzed using symbolic machine learning
Authors: Manca Germana , Cervone Guido
Published: September 2013

This paper analyzes the relationship among different chemical pollutants retrieved from in situ measurements of underground and surface water in a region of possible development. The area of study is the former mine of the Iglesiente district, which is now a United Nations Educational, Scientific, and Cultural Organization (UNESCO) protected region in the island of Sardinia (Italy). A full chemical analysis of water/soil samples were collected at the site in 2004. The data show the presence of several toxic contaminants above the national legal threshold. A symbolic machine learning classifier is employed to learn strong patterns associated with a high level of arsenic (As) in the soil samples. The patterns discovered show complex relationships that include both high and low concentrations of different chemicals. The strongest patterns are found between As and the chemicals which are usually found in the soil. This implies that when As is dissolved in the water table, it is expected these other chemicals are also present. It emerges that a specific relationship of As–phosphates is outlined and is clearly shown by applying the symbolic machine learning classifier. This leads to an understanding of the behavior of these elements in the soil, potential impacts on ecosystems, as well as the pollution of groundwater. Finally, an assertion of the advantages of the algorithm quasi‐optimal learning method is clarified in term of applicability in such circumstances. Copyright © 2013 John Wiley & Sons, Ltd.
Phase Space Density matching of relativistic electrons using the Van Allen Probes: REPT results
Authors: Morley S. K. , Henderson M. G. , Reeves G. D. , W. Friedel R. H. , Baker D. N.
Published: September 2013

Phase Space Density (PSD) matching can be used to identify the presence of nonadiabatic processes, evaluate accuracy of magnetic field models, or to cross‐calibrate instruments. Calculating PSD in adiabatic invariant coordinates requires a global specification of the magnetic field. For a well specified global magnetic field, nonadiabatic processes or inadequate cross calibration will give a poor PSD match. We have calculated PSD(μ, K) for both Van Allen Probes using a range of models and compare these PSDs at conjunctions in L* (for given μ, K). We quantitatively assess the relative goodness of each model for radiation belt applications. We also quantify the uncertainty in the model magnetic field magnitude and the related uncertainties in PSD, which has applications for modeling and particle data without concurrent magnetic field measurements. Using this technique, we show the error in PSD for an energy spectrum observed by the relativistic electron‐proton telescope (REPT) is a factor of ∼1.2 using the TS04 model.
Critical interaction between E1 and E2 glycoproteins determines binding and fusion properties of hepatitis C virus during cell entry
Authors: Douam Florian , Dao Thi Viet Loan , Maurin Guillemette , Fresquet Judith , Mompelat Dimitri , Zeisel Mirjam B. , Baumert Thomas F. , Cosset François-Loïc , Lavillette Dimitri
Published: September 2013

Hepatitis C virus (HCV) envelope glycoproteins E1 and E2 are important mediators for productive cell entry. However, knowledge about their structure, intra- or intermolecular dialogs, and conformational changes is scarce, limiting the design of therapeutic strategies targeting E1E2. Here we sought to investigate how certain domains of E1 and E2 have coevolved to optimize their interactions to promote efficient HCV entry. For this purpose we generated chimeric E1E2 heterodimers derived from two HCV 1a strains to identify and characterize crosstalk between their domains. We found an E1E2 combination that drastically impaired the infectivity of cell culture-derived HCV particles, whereas the reciprocal E1E2 combination led to increased infectivity. Using HCV pseudoparticle assays, we confirmed the opposing entry phenotypes of these heterodimers. By mutagenesis analysis, we identified a particular crosstalk between three amino acids of E1 and the domain III of E2. Its modulation leads to either a full restoration of the functionality of the suboptimal heterodimer or a destabilization of the functional heterodimer. Interestingly, we found that this crosstalk modulates E1E2 binding to HCV entry receptors SR-BI and CD81. In addition, we found for the first time that E1E2 complexes can interact with the first extracellular loop of Claudin-1, whereas soluble E2 did not. These results highlight the critical role of E1 in the modulation of HCV binding to receptors. Finally, we demonstrated that this crosstalk is involved in membrane fusion. Conclusions: These results reveal a multifunctional and crucial interaction between E1 and E2 for HCV entry into cells. Our study highlights the role of E1 as a modulator of HCV binding to receptors and membrane fusion, underlining its potential as an antiviral target. (HEPATOLOGY 2014;59:776–788)
A Content Analysis of Problematic Behavior in Counselor Education Programs
Authors: Brown Maranda
Published: September 2013

Counselor education programs are obligated by accreditation standards and professional codes of ethics to identify counselors‐in‐training whose academic, clinical, and personal performance indicate problematic behavior that would potentially prevent them from entering the profession (McAdams, Foster, & Ward, 2007;Rust, Raskin, & Hill, 2013). Despite these obligations, there are no systematic criteria by which to address problematic behavior. This content analysis describes policies used by the Council for Accreditation of Counseling and Related Educational Programs' doctoral counselor education programs that define, assess, and remediate problematic behavior.
Ethnic Identity and Social‐Cognitive Maturity in a Multicultural Group Experience
Authors: Johnson Jennifer M. , Lambie Glenn W.
Published: September 2013

This study examined a multicultural group experience on students' (N= 94) ethnic identity development and social‐cognitive maturity. Although no differences were identified between treatment and comparison group participants, group therapeutic factors scores were predictive of ethnic identity development and social‐cognitive maturity. Implications for counselor educators and future research are discussed.
Rural High School Youth's Access to and Use of School‐to‐Work Programs
Authors: Hutchins Bryan C. , Akos Patrick
Published: September 2013

Rural youth face numerous barriers that may limit career exposure. School‐to‐work (STW) programs are one tool used to increase exposure and facilitate connections between school and work. Using a nationally representative data set, the authors investigated whether rurality relates to the availability of STW programs and rural youth's program use. Results indicate that most schools provide school‐based services (e.g., career plans/career majors), but few schools offer work‐based services (e.g., internships). Rural schools were more likely to offer vocational–technical prep programs and job shadowing but were less likely to offer school‐based enterprise. After controlling for program availability, the authors found that rural students were less likely to take part in job shadowing and community service. Conclusions are offered for career development research, policy, and practice.
Trends in the History of Vocational Guidance
Authors: Herr Edwin L.
Published: September 2013

In this article, the relationships between vocational guidance and vocational education, employment counseling, career guidance, and career counseling are explored. Also examined are the wide‐ranging federal and state policies that have stimulated and shaped the professional history of vocational guidance, vocational policy, and contemporary terms.
Wetted‐wall corona discharge induced degradation of sulfadiazine antibiotics in aqueous solution
Authors: Rong Shaopeng , Sun Yabing
Published: September 2013

BACKGROUND

Sulfadiazine, is a potent antibacterial agent belonging to the sulfonamide class of antibiotics and is widely used as veterinary and human medicine, has been detected in contaminated water and soils. A cylindrical wetted‐wall corona discharge was applied for the removal of sulfadiazine. The target water was made to flow as a film over the surface of the electrode; the radicals generated at the gas–liquid interface discharge can efficiently reach the flowing‐water film surface.

RESULTS

Initial concentrations of 10 mg L‐1 sulfadiazine can all be removed within 30 min under discharge conditions of 100 W. The degradation of sulfadiazine can be enhanced by the addition of hydrogen radical scavengers, but can be inhibited by adding hydroxyl radical scavengers. Both kinds of radical scavengers can increase the concentrations of H2O2. The wetted‐wall corona discharge was ineffective in mineralization, but it can be enhanced by CCl4. Based on the results of LC–MS analysis, six intermediates were identified and the proposed evolutionary process was investigated.

CONCLUSIONS

Wetted‐wall corona discharge can effectively degrade sulfadiazine in aqueous solution. These results are helpful for exploring new efficient technology and the evolutionary mechanism for antibiotics treatment. © 2013 Society of Chemical Industry
Alanine‐derivatized β‐cyclodextrin bonded silica: structure and adsorption selectivity
Authors: He Kaichen , Qiu Fengxian , Rong Xinshan , Qin Jiao , Yan Jie , Yang Dongya
Published: September 2013

BACKGROUND

Many drug, pharmaceutical and flavoring compounds are racemic mixtures with chiral isomers having nearly identical physical and chemical properties. Phenylalanine is an aromatic alpha‐amino acid that exists in two isomeric forms: D‐phenylalanine (D‐Phe) and L‐phenylalanine (L‐Phe). Due to the different biological natures and pharmacological activities of both enantiomers, it is important to use them in their pure forms for specific therapeutic uses. This work has focused on using novel chiral recognition materials for the chiral separation of racemic phenylalanine.

RESULTS

The static adsorption experiments indicate that prepared β‐cyclodextrin‐bonded silica (CD/SiO2), L‐alanine‐derivatized β‐cyclodextrin‐bonded silica and D‐alanine‐derivatized β‐cyclodextrin‐bonded silica (L‐Ala‐CD/SiO2 and D‐Ala‐CD/SiO2) materials have significantly higher adsorption capacity for D‐phenylalanine (D‐Phe) compared with L‐phenylalanine (L‐Phe), and the selectivity coefficient of CD/SiO2, L‐Ala‐CD/SiO2 and D‐Ala‐CD/SiO2 are 1.99, 1.84 and 3.48, respectively. The equilibrium data were well represented by Langmuir isotherm models. CD/SiO2, L‐Ala‐CD/SiO2 and D‐Ala‐CD/SiO2 were applied in four cycle's regeneration without significant loss in adsorption capacity.

CONCLUSIONS

D‐Ala‐CD/SiO2 has high recognition and binding affinity for D‐Phe molecule. The prepared chiral materials could be applied to chiral separation of the racemic phenylalanine acid solution. © 2013 Society of Chemical Industry
Advances in the development and application of ferrate(VI) for water and wastewater treatment
Authors: Jiang Jia‐Qian
Published: September 2013

Ferrate(VI) ion has the formula FeO42−, and possesses unique properties, vs. strong oxidising potential and simultaneous generation of ferric coagulating species. For this reason, a number of studies have been carried out to investigate the preparation, characterisation and application of ferrate(VI) for water and wastewater treatment. These studies revealed that ferrate(VI) can disinfect microorganisms, partially degrade and/or oxidise organic and inorganic impurities, and remove suspended/colloidal particulate materials in a single dosing and mixing unit process. Most recently, research groups globally have reported using ferrate(VI) to treat emerging micropollutants in water purification processes. Work has not only been limited to fundamental studies but has been driven by the ideas of putting the application of ferrate(VI) into practice; the advantages of the application of ferrate(VI) over existing water and wastewater treatment methods should be shown as should other benefits to the water industry of its use. This paper thus reviews advances in the preparation and use of ferrate(VI), discusses the potential full scale application of ferrate(VI) in water purification and recommends required future research in order to implement ferrate(VI) in practice. © 2013 Society of Chemical Industry
Stable aquaculture of the Japanese lancelet Branchiostoma japonicum for 7 years
Authors: Yasui Kinya , Igawa Takeshi , Kaji Takao , Henmi Yasuhisa
Published: September 2013

Despite advances in the study on animal evolution in the last two decades, paucity of experimental data on cephalochordates comparable to those on the other chordates hinders an integrative understanding of chordate evolutionary history. To obtain lancelet data under well‐controlled experiments, laboratory cultures of lancelets have been performed at several institutions. In a mass culture started in 2005, we have obtained up to three consecutive generations of Branchiostoma japonicum. Using sand substratum, survival rates of laboratory lancelets until maturation have improved to greater than 30%, much higher than compared to previously, and for adults the annual average survival rate was 82.3%. The high survival rate allows maintaining animals at least 6 years and potentially longer. Water temperatures lower than 23°C obviously reduced the frequency of spawning even after the onset of spawning period, and 1–2 days after changing the temperature at 25°C animals became spawned well. We also observed obvious sex reversal from male to female in individuals that had been cultured for 3 years or more. Our continuous culture has provided sufficient materials for vital experiments on early development and for studying metamorphosis, as well as for the conservation of wild populations. The subculture of successive laboratory generations will provide a valuable resource for genetic studies. J. Exp. Zool. (Mol. Dev. Evol.) 320B: 538–547, 2013. © 2013 Wiley Periodicals, Inc.
Novel design and synthesis of a radioiodinated glycolipid analog as an acceptor substrate for N‐acetylglucosaminyltransferase V
Authors: Arimitsu Kenji , Kimura Hiroyuki , Kajimoto Tetsuya , Ono Masahiro , Ohmomo Yoshiro , Yamashita Masayuki , Node Manabu , Saji Hideo
Published: September 2013

Guided by the known molecular recognition interactions between N‐acetylglucosaminyltransferase V (GnT‐V) and certain synthetic substrates, we synthesized a radiolabeled double‐stranded glycolipid composed of a long‐chain alkyl unit and a radioiodinated phenylalkyl unit, [125I]‐2‐[N‐(2‐hydroxy‐3‐hexadecyloxy)propyl‐15‐(4‐iodophenyl)pentadecanecarboxamido]ethyl 2‐acetamido‐2‐deoxy‐β‐d‐glucopyranosyl‐(1→2)‐α‐d‐mannopyranosyl‐(1→6)‐β‐d‐glucopyranoside ([125I]2), as a novel intravital glycolipid mimic substrate of GnT‐V. The radioactive iodine (125I) was incorporated via iododestannylation of the phenyltributyltin derivative, 2‐[N‐(2‐acetoxy‐3‐hexadecyloxy)propyl‐15‐(4‐tributylstannylphenyl)pentadecanecarboxamido]ethyl 3,4,6‐tri‐O‐acetyl‐2‐acetamido‐2‐deoxy‐β‐d‐glucopyranosyl‐(1→2)‐3,4,6‐O‐acetyl‐α‐d‐mannopyranosyl‐(1→6)‐2,3,4‐tri‐O‐acetyl‐β‐d‐glucopyranoside (26). Subsequent deacetylation at the final step afforded [125I]2.
Assessment of inflammation with a very small iron‐oxide particle in a murine model of reperfused myocardial infarction
Authors: Protti Andrea , Dong Xuebin , Andia Marcelo E. , Yu Bin , Dokukina Kate , Chaubey Sanjay , Phinikaridou Alkystis , Vizcay‐Barrena Gema , Taupitz Matthias , Botnar Rene M. , Shah Ajay M.
Published: September 2013

Purpose

To investigate a very small iron‐oxide particle (VSOP) in a mouse model of acute ischemia‐reperfusion to access the mechanism of such particles in areas of myocardial inflammation.

Materials and Methods

Animals were injected with VSOP at several time points, in a mouse model of acute myocardial infarction (MI), before and after MI. MRI was used to localize areas of VSOP enhancement, evaluate VSOP areas extension, and determine the related T2* values. Histology, electron microscopy, macrophage counting, and Evan's Blue staining were also performed.

Results

We found that areas of VSOP uptake decreased from 1 to 8 days post‐MI while the related T2* values increased. T2* and VSOP areas, defined from MRI data, correlated well between 1 and 3 days post‐MI but not at 7 days after injection. Histological analysis and electron microscopy showed colocalization of macrophages with areas of VSOP staining. However, there was no correlation between number of macrophages and the extension of the VSOP areas achieved by MR. We found that only areas of increased permeability (assessed by Evan's Blue staining) showed colocalization of macrophages and VSOP uptake.

Conclusion

This study demonstrates that VSOP allows the assessment of myocardial inflammation associated with increased permeability during infarct healing in a mouse model of ischemia‐reperfusion. J. Magn. Reson. Imaging 2014;39:598–608. © 2013 Wiley Periodicals, Inc.
Disclosing incidental findings in brain research: The rights of minors in decision‐making
Authors: Di Pietro Nina C. , Illes Judy
Published: September 2013

MRI is used routinely in research with children to generate new knowledge about brain development. The detection of unexpected brain abnormalities (incidental findings; IFs) in these studies presents unique challenges. While key issues surrounding incidence and significance, duty of care, and burden of disclosure have been addressed substantially for adults, less empirical data and normative analyses exist for minors who participate in minimal risk research. To identify ethical concerns and fill existing gaps, we conducted a comprehensive review of papers that focused explicitly on the discovery of IFs in minors. The discourse in the 21 papers retrieved for this analysis amply covered practical issues such as informed consent and screening, difficulties in ascertaining clinical significance, the economic costs and burden of responsibility on researchers, and risks (physical or psychological). However, we found little discussion about the involvement of minors in decisions about disclosure of IFs in the brain, especially for IFs of low clinical significance. In response, we propose a framework for managing IFs that integrates practical considerations with explicit appreciation of rights along the continuum of maturity. This capacity‐adjusted framework emphasizes the importance of involving competent minors and respecting their right to make decisions about disclosure. J. Magn. Reson. Imaging 2013;38:1009–1013. © 2013 Wiley Periodicals, Inc.
Validation of an MRI‐based method to assess patellofemoral joint contact areas in loaded knee flexion in vivo
Authors: McWalter Emily J. , O'Kane Colm M. , FitzPatrick David P. , Wilson David R.
Published: September 2013

Purpose

To develop and validate short axial and sagittal MRI scans (<1min) to assess in vivo patellofemoral contact areas in loaded knee flexion.

Materials and Methods

Contact area was assessed in four cadaver knee specimens from axial and sagittal scans using two contact area extraction techniques (delineation and intersection) and three calculation techniques (slice thickness multiplication, linear interpolation, and spline interpolation). Error was expressed as the mean absolute and percentage difference from a dye staining‐based reference standard. Intrareader and intrasubject repeatability, expressed as the mean standard deviation, was determined.

Results

Contact area assessments from the sagittal MRI scans using the delineation and slice thickness multiplication technique had the smallest error (47.7 ± 38.1 mm2 or 10.7%). The intrareader repeatability from assessments using the sagittal scans was smaller than those using the axial scans when the delineation method was used (<9.4 ± 4.3 mm2 and <15.4 ± 14.1 mm2, respectively). The intrasubject repeatability of the assessment from the sagittal scan was less than 39.9 ± 23.0 mm2.

Conclusion

This protocol yields assessments of contact area in less than 1 minute that have errors similar to those made using scans many times longer and can be used in series with kinematic scans to carry out simultaneous assessments in vivo to study patellofemoral joint disease. J. Magn. Reson. Imaging 2014;39:978–987. © 2013 Wiley Periodicals, Inc.
More than biofuels – Potential uses of microalgae as sources of high‐value lipids
Authors: Lee Chang Kim Jye , Nichols Peter D. , Blackburn Susan I.
Published: September 2013

Cultivation of microalgae has potential in producing a feedstock for biofuels and, in addition, high‐value lipid bioproducts such as long‐chain (⪈C20, LC) omega‐3 oils, carotenoid pigments and squalene, as well as other non‐lipid materials including exopolysaccharide. The high‐value LC omega‐3 oils have been conventionally sourced from fish. This paper provides a perspective on our recent study of the heterotrophic growth of thraustochytrids for their wider biotechnological potential, including as a source of a range of higher value lipids in addition to biofuels.
MR and CT based treatment planning for mTHPC mediated interstitial photodynamic therapy of head and neck cancer: Description of the method
Authors: Karakullukcu Baris , van Veen Robert L.P. , Aans Jan Bonne , Hamming‐Vrieze Olga , Navran Arash , Teertstra H. Jelle , van den Boom Ferrie , Niatsetski Yuri , Sterenborg H.J.C.M. , Tan I. Bing
Published: September 2013

Background and Objective

Interstitial photodynamic therapy is a potentially important tool in the management of voluminous or deep‐seated recurrent head and neck cancers.

Study Design/Methods

The described treatment algorithm in this manuscript consists of the treatment simulation, implantation of light sources, verification, modification of the treatment plan if necessary, and illumination. The tumor is delineated on imaging sections (CT, MRI, and/or PET/CT) and the treatment is simulated by virtually introducing light sources to the tumor volume on specially modified brachytherapy software. This enables us to determine if the treatment is technically feasible, and information about approximate number and location of light sources necessary. Following implantation of catheters in which the light sources will be introduced, CT or MR scan is performed to verify the actual location of the implanted catheters. The verification‐CT is imported to the software and co‐registered with pre‐treatment images to observe the deviations from the simulation. The simulation is run again with the actual position of the light sources to determine if any additional light sources are necessary and adaptation of the source length in order to cover the tumor volume (modification). Thereafter the tumor is illuminated.

Results

This method has the potential to help with identifying iPDT feasible patients by simulating before the actual treatment. The suboptimal placement of light sources can be identified and corrected. The simulations were documented and saved for subsequent evaluation of the technique.

Conclusion

The proposed technique can help standardize and document iPDT. Lasers Surg. Med. 45:517–523, 2013. © 2013 Wiley Periodicals, Inc.
Arithmetic toric varieties
Authors: Elizondo E. Javier , Lima‐Filho Paulo , Sottile Frank , Teitler Zach
Published: September 2013

We study toric varieties over a fieldkthat split in a Galois extensionusing Galois cohomology with coefficients in the toric automorphism group. Part of this Galois cohomology fits into an exact sequence induced by the presentation of the class group of the toric variety. This perspective helps to compute the Galois cohomology, particularly for cyclic Galois groups. We use Galois cohomology to classifyk‐forms of projective spaces whenis cyclic, and we also studyk‐forms of surfaces.
Dose–response plasma appearance of coffee chlorogenic and phenolic acids in adults
Authors: Renouf Mathieu , Marmet Cynthia , Giuffrida Francesca , Lepage Mélissa , Barron Denis , Beaumont Maurice , Williamson Gary , Dionisi Fabiola
Published: September 2013

Scope

Coffee contains phenolic compounds, mainly chlorogenic acids (CGAs). Even though coffee intake has been associated with some health benefits in epidemiological studies, the bioavailability of coffee phenolics is not fully understood.

Objective and study design

We performed a dose–response study measuring plasma bioavailability of phenolics after drinking three increasing, but still nutritionally relevant doses of instant pure soluble coffee. The study design was a one treatment (coffee) three‐dose randomized cross‐over design, with a washout period of 2 wks between visits.

Results

CGAs, phenolic acids, and late‐appearing metabolites all increased with increasing ingested dose. Hence, the sum of area under the curve was significantly higher for the medium to low dose, and high to medium dose, by 2.23‐ and 2.38‐fold, respectively. CGAs were not well absorbed in their intact form, regardless of the dose. CGA and phenolic acids appeared rapidly in plasma, indicating an early absorption in the gastrointestinal tract. Late‐appearing metabolites were the most abundant, regardless of the dose.

Conclusion

This study confirmed previous findings about coffee bioavailability but also showed that coffee phenolics appear in a positive dose–response manner in plasma when drank at nutritionally relevant doses.
A comparison of quantitative nuclear magnetic resonance methods: internal, external, and electronic referencing
Authors: Cullen Christopher H. , Ray G. Joseph , Szabo Christina M.
Published: September 2013

The performance of three quantitative NMR methods was compared in terms of short‐term and long‐term precision and accuracy, robustness, linear range, and general applicability. The Internal Reference method employs a reference material co‐dissolved with sample; the External Reference method employs a reference material contained in a separate solution; and the third method, known as Electronic REference To access In vivo Concentrations (ERETIC), employs an externally calibrated digital reference peak. The Internal Reference method results were the most precise and remained stable within 0.1% for at least 4 weeks. The results from the External Reference and ERETIC methods were practically equivalent to each other during this time. These methods exhibited small differences relative to the standard set by the Internal Reference method and slightly lower precision, establishing them as practical alternatives to the Internal Reference method. In contrast to the Internal Reference method, the External Reference and ERETIC methods possess several advantages that address peak overlap, flexibility of calibration, and duration of applicability. The study was designed such that each spectrum contained the information needed to compare the three methods while all other variables were kept constant. Applicability of pulse width compensation is addressed. ERETIC software compensation and minor adjustments to 90° pulse width were concluded to be unnecessary for this system. Although each of the methods was applied here to specifically calculate and compare chemical purity values, this evaluation applies generally to absolute quantitation by NMR. Copyright © 2013 John Wiley & Sons, Ltd.
Activation of pluripotency genes by a nanotube‐mediated protein delivery system
Authors: Cho Seong Je , Choi Hyun Woo , Cho Jaegeol , Jung Suntae , Seo Han Geuk , Do Jeong Tae
Published: September 2013

The overexpression of cell reprogramming factors (Oct4, Sox2, Klf4, Nanog, and c‐Myc) allows differentiated cells to revertto an earlier developmental stage. Differentiated cells can also be reprogrammed by directly delivering reprogramming proteins tagged with cell‐penetrating peptides, which allow the proteins to pass through the cell membrane and into the cytoplasm–although this method has been an inefficient process. Here, we describe a novel technique for delivering reprogramming proteins into cells using titanium oxide (TiO2) nanotubes, which show no cytotoxic effects and do not affect cell proliferation. TiO2 nanotubes successfully transferred the above‐mentioned reprogramming factors into differentiated somatic cells. After 3 weeks of treatment with protein‐conjugated nanotubes, the somatic cells adopted an embryonic stem cell‐like morphology and expressed activated Oct4‐green fluorescent protein, a pluripotency biomarker. Our results indicate that TiO2 nanotubes can be used to directly deliver reprogramming factors into somatic cells to induce pluripotency. Mol. Reprod. Dev. 80: 1000–1008, 2013. © 2013 Wiley Periodicals, Inc.
Enabling hyperpolarized 129Xe MR spectroscopy and imaging of pulmonary gas transfer to the red blood cells in transgenic mice expressing human hemoglobin
Authors: Freeman Matthew S. , Cleveland Zackary I. , Qi Yi , Driehuys Bastiaan
Published: September 2013

Purpose

Hyperpolarized (HP) 129Xe gas in the alveoli can be detected separately from 129Xe dissolved in pulmonary barrier tissues (blood plasma and parenchyma) and red blood cells (RBCs) of humans, allowing this isotope to probe impaired gas uptake. Unfortunately, mice, which are favored as lung disease models, do not display a unique RBC resonance, thus limiting the preclinical utility of 129Xe MR. Here we overcome this limitation using a commercially available strain of transgenic mice that exclusively expresses human hemoglobin.

Methods

Dynamic HP 129Xe MR spectroscopy, and three‐dimensional radial MRI of gaseous and dissolved 129Xe were performed in both wild‐type (C57BL/6) and transgenic mice.

Results

Unlike wild‐type animals, transgenic mice displayed two dissolved 129Xe NMR peaks at 198 and 217 ppm, corresponding to 129Xe dissolved in barrier tissues and RBCs, respectively. Moreover, signal from these resonances could be imaged separately, using a 1‐point variant of the Dixon technique.

Conclusion

It is now possible to examine the dynamics and spatial distribution of pulmonary gas uptake by the RBCs of mice using HP 129Xe MR spectroscopy and imaging. When combined with ventilation imaging, this ability will enable translational “mouse‐to‐human” studies of impaired gas exchange in a variety of pulmonary diseases. Magn Reson Med 70:1192–1199, 2013. © 2013 Wiley Periodicals, Inc.
Susceptibility map‐weighted imaging (SMWI) for neuroimaging
Authors: Gho Sung‐Min , Liu Chunlei , Li Wei , Jang Ung , Kim Eung Yeop , Hwang Dosik , Kim Dong‐Hyun
Published: September 2013

Purpose

To propose a susceptibility map‐weighted imaging (SMWI) method by combining a magnitude image with a quantitative susceptibility mapping (QSM) ‐based weighting factor thereby providing an alternative contrast compared with magnitude image, susceptibility‐weighted imaging, and QSM.

Methods

A three‐dimensional multi‐echo gradient echo sequence is used to obtain the data. The QSM was transformed to a susceptibility mask that varies in amplitude between zero and unity. This mask was multiplied several times with the original magnitude image to create alternative contrasts between tissues with different susceptibilities. A temporal domain denoising method to enhance the signal‐to‐noise ratio was further applied. Optimal reconstruction processes of the SMWI were determined from simulations.

Results

Temporal domain denoising enhanced the signal‐to‐noise ratio, especially at late echoes without spatial artifacts. From phantom simulations, the optimal number of multiplication and threshold values was chosen. Reconstructed SMWI created different contrasts based on its weighting factors made from paramagnetic or diamagnetic susceptibility tissue and provided an excellent delineation of microhemorrhage without blooming artifacts typically caused by the nonlocal property of phase.

Conclusion

SMWI presents an alternative contrast for susceptibility‐based imaging. The validity of this method was demonstrated using in vivo data. This proposed method together with denoising allows high‐quality reconstruction of susceptibility‐weighted image of human brain in vivo. Magn Reson Med 72:337–346, 2014. © 2013 Wiley Periodicals, Inc.
Quantitative lung perfusion evaluation using fourier decomposition perfusion MRI
Authors: Kjørstad Åsmund , Corteville Dominique M.R. , Fischer Andre , Henzler Thomas , Schmid‐Bindert Gerald , Zöllner Frank G. , Schad Lothar R.
Published: September 2013

Purpose

To quantitatively evaluate lung perfusion using Fourier decomposition perfusion MRI. The Fourier decomposition (FD) method is a noninvasive method for assessing ventilation‐ and perfusion‐related information in the lungs, where the perfusion maps in particular have shown promise for clinical use. However, the perfusion maps are nonquantitative and dimensionless, making follow‐ups and direct comparisons between patients difficult. We present an approach to obtain physically meaningful and quantifiable perfusion maps using the FD method.

Methods

The standard FD perfusion images are quantified by comparing the partially blood‐filled pixels in the lung parenchyma with the fully blood‐filled pixels in the aorta. The percentage of blood in a pixel is then combined with the temporal information, yielding quantitative blood flow values. The values of 10 healthy volunteers are compared with SEEPAGE measurements which have shown high consistency with dynamic contrast enhanced‐MRI.

Results

All pulmonary blood flow (PBF) values are within the expected range. The two methods are in good agreement (mean difference = 0.2 mL/min/100 mL, mean absolute difference = 11 mL/min/100 mL, mean PBF‐FD = 150 mL/min/100 mL, mean PBF‐SEEPAGE = 151 mL/min/100 mL). The Bland‐Altman plot shows a good spread of values, indicating no systematic bias between the methods.

Conclusion

Quantitative lung perfusion can be obtained using the Fourier Decomposition method combined with a small amount of postprocessing. Magn Reson Med 72:558–562, 2014. © 2013 Wiley Periodicals, Inc.
An improved trap design for decoupling multinuclear RF coils
Authors: Meyerspeer Martin , Roig Eulalia Serés , Gruetter Rolf , Magill Arthur W.
Published: September 2013

Purpose

Multinuclear magnetic resonance spectroscopy and imaging require a radiofrequency probe capable of transmitting and receiving at the proton and non‐proton frequencies. To minimize coupling between probe elements tuned to different frequencies, LC (inductor‐capacitor) traps blocking current at the 1H frequency can be inserted in non‐proton elements. This work compares LC traps with LCC traps, a modified design incorporating an additional capacitor, enabling control of the trap reactance at the low frequency while maintaining 1H blocking.

Methods

Losses introduced by both types of trap were analysed using circuit models. Radiofrequency coils incorporating a series of LC and LCC traps were then built and evaluated at the bench. LCC trap performance was then confirmed using 1H and 13C measurements in a 7T human scanner.

Results

LC and LCC traps both effectively block interaction between non‐proton and proton coils at the proton frequency. LCC traps were found to introduce a sensitivity reduction of 5±2%, which was less than half of that caused by LC traps.

Conclusion

Sensitivity of non‐proton coils is critical. The improved trap design, incorporating one extra capacitor, significantly reduces losses introduced by the trap in the non‐proton coil. Magn Reson Med 72:584–590, 2014. © 2013 Wiley Periodicals, Inc.
Phase reconstruction from multiple coil data using a virtual reference coil
Authors: Parker Dennis L. , Payne Allison , Todd Nick , Hadley J. Rock
Published: September 2013

Purpose

This study develops a method to obtain optimal estimates of absolute magnetization phase from multiple‐coil MRI data.

Theory and Methods

The element‐specific phases of a multi‐element receiver coil array are accounted for by using the phase of a real or virtual reference coil that is sensitive over the entire imaged volume. The virtual‐reference coil is generated as a weighted combination of measurements from all receiver coils. The phase‐corrected multiple coil complex images are combined using the inverse covariance matrix. These methods are tested on images of an agar phantom, an in vivo breast, and an anesthetized rabbit obtained using combinations of four, nine, and three receiver channels, respectively.

Results

The four‐ and three‐channel acquisitions require formation of a virtual‐reference receiver coil while one channel of the nine‐channel receive array has a sensitivity profile covering the entire imaged volume. Referencing to a real or virtual coil gives receiver phases that are essentially identical except for the individual receiver channel noise. The resulting combined images, which account for receiver channel noise covariance, show the expected reduction in phase variance.

Conclusion

The proposed virtual reference coil method determines a phase distribution for each coil from which an optimal phase map can be obtained. Magn Reson Med 72:563–569, 2014. © 2013 Wiley Periodicals, Inc.
Flow compensated quantitative susceptibility mapping for venous oxygenation imaging
Authors: Xu Bo , Liu Tian , Spincemaille Pascal , Prince Martin , Wang Yi
Published: September 2013

Purpose

Venous blood oxygen saturation is an indicator of brain oxygen consumption and can be measured directly from quantitative susceptibility mapping (QSM) by deconvolving the MR phase signal. However, accurate estimation of the susceptibility of blood may be affected by flow induced phase in the presence of imaging gradient and the inhomogeneous susceptibility field gradient. The purpose of this study is to correct the flow induced error in QSM for improved venous oxygenation quantification.

Methods

Flow compensation is proposed for QSM by using a fully flow compensated multi‐echo gradient echo sequence for data acquisition. A quadratic fit of the phase with respect to echo time is employed for the flow phase in the presence of inhomogeneity field gradients. Phantom and in vivo experiments were carried out to validate the proposed method.

Results

Phantom experiments demonstrated reduced error in the estimated field map and susceptibility map. Initial data in in vivo human imaging demonstrated improvements in the quantitative susceptibility map and in the estimated venous oxygen saturation values.

Conclusion

Flow compensated multi‐echo acquisition and an adaptive‐quadratic fit of the phase images improves the quantitative susceptibility map of blood flow. The improved vein susceptibility enables in vivo measurement of venous oxygen saturation throughout the brain. Magn Reson Med 72:438–445, 2014. © 2013 Wiley Periodicals, Inc.
High‐resolution ultrasound visualization of the subcutaneous nerves of the forearm: A feasibility study in anatomic specimens
Authors: Moritz Thomas , Prosch Helmut , Pivec Christopher H. , Sachs Alexander , Pretterklieber Michael L. , Kriechbaumer Lukas , Happak Wolfgang , Bodner Gerd
Published: September 2013

Introduction: The aim of this ultrasound‐anatomical study was to evaluate the ability of high‐resolution ultrasound (HRUS) to visualize and infiltrate small subcutaneous nerves of the forearm in anatomic specimens. Methods: Seven nonembalmed human bodies (4 men, 3 women; mean age at death, 60 years) were included in the study. Two investigators scanned the anatomic specimens using 15‐MHz and 18‐MHz HRUS transducers. The lateral, medial, and posterior antebrachial cutaneous nerves were scanned and interventionally marked with ink using HRUS‐guidance. Subsequently, dissections were performed to assess the anatomical correlation of HRUS findings. Results: All 3 nerves were identified consistently using HRUS. The precision of the ink‐markings was excellent, with good correlation with the small peripheral branches of all 3 nerves. Conclusions: HRUS can identify precisely the small subcutaneous nerves of the forearm and may aid in both diagnosis and therapy in cases of neuropathy. Muscle Nerve 49: 676–679, 2014
Electrodiagnostic features of true neurogenic thoracic outlet syndrome
Authors: Tsao Bryan E. , Ferrante Mark A. , Wilbourn Asa J. , Shields Robert W.
Published: September 2013

Introduction: We report the electrodiagnostic (EDX) features of 32 patients with surgically verified true neurogenic thoracic outlet syndrome (TN‐TOS). Methods: Retrospective record review. Results: We found uniform EDX evidence of a chronic axon loss process that affected the lower portion of the brachial plexus and disproportionately involved the T1 more than the C8 sensory and motor fibers. Because of this relationship, the medial antebrachial cutaneous sensory nerve (T1) and median motor (T1 > C8) study combination was abnormal in 89%, whereas response combinations that primarily assessed the C8 fibers were less frequently affected. Conclusions: The characteristic EDX features of TN‐TOS are T1 > C8 nerve fiber involvement. A comprehensive EDX examination of the lower plexus with contralateral comparison studies is imperative to diagnose this disorder accurately. Muscle Nerve 49: 724–727, 2014
Pathophysiology of immune‐mediated demyelinating neuropathies—part I: Neuroscience
Authors: Franssen Hessel , Straver Dirk C.G.
Published: September 2013

This first article of this review deals with neuroscientific aspects of immune‐mediated demyelinating neuropathies. It describes the anatomy and physiology of normal myelinated axons, methods of studying peripheral nerve physiology, pathophysiological consequences of demyelination or damage at the node of Ranvier, and the mechanisms that may lead to impaired axonal membrane dysfunction or axonal degeneration. This article (part I) will be followed by a second (part II) dealing with clinical aspects of these neuropathies. Muscle Nerve 48: 851–864, 2013