bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescence Intensity Modulation in Photochromic Conjugated Polymer Systems
Authors: Harbron Elizabeth J.
Published: May 2013

The ability to modulate fluorescence intensity with a light signal enables a variety of applications based on fluorescence imaging. One approach to fluorescence photomodulation involves using a photochromic moiety that responds to a light signal in conjunction with a nearby fluorophore. We employ conjugated polymers based on poly(p‐phenylene vinylene) (PPV) as the fluorophore in photochrome‐fluorophore systems for fluorescence modulation. Advantages of using conjugated polymers for this purpose include their intrinsic energy migration processes that enable amplified fluorescence quenching as well as their processability. Here we present examples of PPV‐based photomodulation systems that employ photochromic dyes from three common photochromic families: azobenzenes, spironaphthoxazines, and diarylethenes. In all cases we observe reversible fluorescence quenching due to fluorescence resonance energy transfer to the photogenerated form of the photochrome. Examples of the photomodulation of photochromic PPV systems in organic solution, polymer films, and conjugated polymer nanoparticles are presented.
Rapid and label‐free identification of normal spermatozoa based on image analysis and micro‐Raman spectroscopy
Authors: Huang Zufang , Chen Guannan , Chen Xiwen , Wang Jing , Chen Jinhua , Lu Peng , Chen Rong
Published: May 2013

Semen analysis is performed for evaluation of fertility disorders, however it is susceptible to subjectivity of investigators, and lacking of objective criterion for sperm cell quality remains a problem. There is an ongoing debate on which criteria should be employed to define normal spermatozoa. Here, the aim of our study is to evaluate the possibility of label‐free and rapid identification of normal sperm cell through the use of image analysis combined with micro‐Raman spectroscopy. By using a smooth‐surfaced and hydrophobic substrate, spermatozoa smear was rapidly prepared for microscopic imaging and acrosome area can be clearly visualized without any extra stains; then a self‐written image analysis program was utilized to segment sperm head and acrosome area and automatically calculates morphological indices. Most important, intensity ratio of 1055 cm–1 to 1095 cm–1 from the obtained Raman spectra is found to indicate a potential biomarker for assessing the sperm DNA integrity. Our preliminary study demonstrates that micro‐Raman spectroscopy combined with image analysis can be a potentially useful tool for rapid and label‐free identification of normal sperm cell by providing both morphological and biochemical information. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kombucha‐synthesized bacterial cellulose: Preparation, characterization, and biocompatibility evaluation
Authors: Zhu Changlai , Li Feng , Zhou Xinyang , Lin Lin , Zhang Tianyi
Published: May 2013

Bacterial cellulose (BC) is a natural biomaterial with unique properties suitable for tissue engineering applications, but it has not yet been used for preparing nerve conduits to repair peripheral nerve injuries. The objectives of this study were to prepare and characterize the Kampuchea‐synthesized bacterial cellulose (KBC) and further evaluate the biocompatibility of KBC with peripheral nerve cells and tissues in vitro and in vivo. KBC membranes were composed of interwoven ribbons of about 20–100 nm in width, and had a high purity and the same crystallinity as that of cellulose Iα. The results from light and scanning electron microscopy, MTT assay, flow cytometry, and RT‐PCR indicated that no significant differences in the morphology and cell function were observed between Schwann cells (SCs) cultured on KBC membranes and glass slips. We also fabricated a nerve conduit using KBC, which was implanted into the spatium intermusculare of rats. At 1, 3, and 6 weeks post‐implantation, clinical chemistry and histochemistry showed that there were no significant differences in blood counts, serum biochemical parameters, and tissue reactions between implanted rats and sham‐operated rats. Collectively, our data indicated that KBC possessed good biocompatibility with primary cultured SCs and KBC did not exert hematological and histological toxic effects on nerve tissues in vivo. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1548–1557, 2014.
Passive films on metallic biomaterials under simulated physiological conditions
Authors: Pound B. G.
Published: May 2013

The metallic materials used for implantable medical devices are predominantly stainless steels, Ti and its alloys, and Co‐Cr alloys. The corrosion resistance of each of these materials is associated with a passive oxide film on its surface. Since corrosion resistance is crucial to implant performance, considerable effort has been focused on understanding the nature of the passive film present under physiological conditions. Surface analytical techniques and electrochemical impedance spectroscopy have been used in a number of studies to investigate the passive film formed on metallic biomaterials in simulated physiological solutions. This review focuses on the surface characteristics of these materials with regard to composition, thickness, and impedance of the passive films. Of particular interest are changes in the films with surface treatment and the nature of the films developed over time in the simulated solutions. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1595–1604, 2014.
Host response to microgel coatings on neural electrodes implanted in the brain
Authors: Gutowski Stacie M. , Templeman Kellie L. , South Antoinette B. , Gaulding Jeffrey C. , Shoemaker James T. , LaPlaca Michelle C. , Bellamkonda Ravi V. , Lyon L. Andrew , García Andrés J.
Published: May 2013

The performance of neural electrodes implanted in the brain is often limited by host response in the surrounding brain tissue, including astrocytic scar formation, neuronal cell death, and inflammation around the implant. We applied conformal microgel coatings to silicon neural electrodes and examined host responses to microgel‐coated and uncoated electrodes following implantation in the rat brain. In vitro analyses demonstrated significantly reduced astrocyte and microglia adhesion to microgel‐coated electrodes compared to uncoated controls. Microgel‐coated and uncoated electrodes were implanted in the rat brain cortex and the extent of activated microglia and astrocytes as well as neuron density around the implant were evaluated at 1, 4, and 24 weeks postimplantation. Microgel coatings reduced astrocytic recruitment around the implant at later time points. However, microglial response indicated persistence of inflammation in the area around the electrode. Neuronal density around the implanted electrodes was also lower for both implant groups compared to the uninjured control. These results demonstrate that microgel coatings do not significantly improve host responses to implanted neural electrodes and underscore the need for further improvements in implantable materials. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1486–1499, 2014.
Thiol‐ene/acrylate substrates for softening intracortical electrodes
Authors: Ware Taylor , Simon Dustin , Liu Clive , Musa Tabassum , Vasudevan Srikanth , Sloan Andrew , Keefer Edward W. , Rennaker Robert L. , Voit Walter
Published: May 2013

Neural interfaces have traditionally been fabricated on rigid and planar substrates, including silicon and engineering thermoplastics. However, the neural tissue with which these devices interact is both 3D and highly compliant. The mechanical mismatch at the biotic–abiotic interface is expected to contribute to the tissue response that limits chronic signal recording and stimulation. In this work, novel ternary thiol‐ene/acrylate polymer networks are used to create softening substrates for neural recording electrodes. Thermomechanical properties of the substrates are studied through differential scanning calorimetry and dynamic mechanical analysis both before and after exposure physiological conditions. This substrate system softens from more than 1 GPa to 18 MPa on exposure to physiological conditions: reaching body temperature and taking up less than 3% fluid. The impedance of 177 µm2 gold electrodes electroplated with platinum black fabricated on these substrates is measured to be 206 kΩ at 1 kHz. Specifically, intracortical electrodes are fabricated, implanted, and used to record driven neural activity. This work describes the first substrate system that can use the full capabilities of photolithography, respond to physiological conditions by softening markedly after insertion, and record driven neural activity for 4 weeks. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1–11, 2014.
A simple but effective modeling strategy for structural properties of non‐heme Fe(II) sites in proteins: Test of force field models and application to proteins in the AlkB family
Authors: Pang Xueqin , Han Keli , Cui Qiang
Published: May 2013

To facilitate computational study of proteins in the AlkB family and related α‐ketoglutarate/Fe(II)‐dependent dioxygenases, we have tested a simple modeling strategy for the non‐heme Fe(II) site in which the iron is represented by a simple +2 point charge with Lennard‐Jones parameters. Calculations for an AlkB active site model in the gas phase and ∼150 ns molecular dynamics (MD) simulations for two enzyme‐dsDNA complexes (E. coli AlkB‐dsDNA and ABH2‐dsDNA) suggest that this simple modeling strategy provides a satisfactory description of structural properties of the Fe(II) site in AlkB enzymes, provided that care is exercised to control the binding mode of carboxylate (Asp) to the iron. MD simulations using the model for AlkB‐dsDNA and ABH2‐dsDNA systems find that although the structural features for the latter are overall in good agreement with the crystal structure, the dsDNA, and AlkB‐dsDNA interface undergo substantial changes during the MD simulations from the crystal structure. Even for ABH2, new interactions form between a long loop region and dsDNA upon structural relaxation of the loop, supporting the role of this loop in DNA binding despite the lack of interactions between them in the crystal structure. Analysis of DNA backbone torsional distributions helps identify regions that adopt strained conformations. Collectively, the results highlight that crystal packing may have a significant impact on the structure of protein‐DNA complexes; the simulations also provide additional insights regarding why AlkB and ABH2 prefer single‐strand and double‐strand DNA, respectively, as substrate. © 2013 Wiley Periodicals, Inc.
Hamiltonian Cycle Systems Which Are Both Cyclic and Symmetric
Authors: Buratti Marco , Merola Francesca
Published: May 2013

The notion of a symmetric Hamiltonian cycle system (HCS) of a graph Γ has been introduced and studied by J. Akiyama, M. Kobayashi, and G. Nakamura [J Combin Des 12 (2004), 39–45] for , by R. A. Brualdi and M. W. Schroeder [J Combin Des 19 (2011), 1–15] for , and then naturally extended by V. Chitra and A. Muthusamy [Discussiones Mathematicae Graph Theory, to appear] to the multigraphs and . In each case, there must be an involutory permutation ψ of the vertices fixing all the cycles of the HCS and at most one vertex. Furthermore, for , this ψ should be precisely the permutation switching all pairs of endpoints of the edges of I.

An HCS is cyclic if it is invariant under some cyclic permutation of all the vertices. The existence question for a cyclic HCS of has been completely solved by Jordon and Morris [Discrete Math (2008), 2440–2449]—and we note that their cyclic construction is also symmetric for (mod 8). It is then natural to study the existence problem of an HCS of a graph or multigraph Γ as above which is both cyclic and symmetric. In this paper, we completely solve this problem: in the case of even order, the final answer is that cyclicity and symmetry can always cohabit when a cyclic solution exists. On the other hand, imposing that a cyclic HCS of odd order is also symmetric is very restrictive; we prove in fact that an HCS of with both properties exists if and only if is a prime.
Population‐based analysis of prognostic indicators in sebaceous carcinoma of the head and neck
Authors: Thomas W. Walsh , Fritsch Valerie A. , Lentsch Eric J.
Published: May 2013

Objectives/Hypothesis

Due to the rarity of sebaceous carcinoma of the head and neck, few large series have been reported and prognostic factors remain largely undetermined. This study presents prognostic factors in survival in sebaceous carcinoma of the head and neck.

Study Design

Retrospective analysis was performed using the Surveillance Epidemiology and End Results (SEER) database for patients diagnosed with sebaceous carcinoma of the head and neck (SCHN).

Methods

Clinicopathologic, treatment data, and 5‐year disease specific survival were analyzed using univariable and multivariable regression analysis and Kaplan‐Meier methodology.

Results

Of the 1,433 patients identified to have SCHN, 16 were node‐positive (1.14%). On multivariable analysis, independent prognostic indicators were: age at diagnosis (HR = 1.03, P = .021), tumor grade (HR = 4.97, P = .038), and distant metastasis (HR = 7.52, P = .006). Nodal metastasis occurred exclusively with poorly or undifferentiated tumors and was not a significant prognostic factor on multivariable analysis.

Conclusion

Elderly patients and patients with poorly differentiated tumors and/or distant disease at presentation have the highest risk of disease‐specific mortality. Lymph node metastasis does not appear to be an independent prognostic factor in sebaceous cell carcinoma.

Level of Evidence

2b. Laryngoscope, 123:2165–2169, 2013
The effect of anterior palatine blocks on bleeding in hereditary hemorrhagic telangiectasia nasal surgery
Authors: Guthrie Carly C. , Karnezis Tom T. , Orosco Ryan K. , Bishop Michael L. , Davidson Terence M.
Published: May 2013

Objectives/Hypothesis

When combined with local sphenopalatine (SP) injection and moderate hypotension, transoral or transcutaneous local injection of the anterior palatine (AP) vessels reduces intraoperative bleeding in hereditary hemorrhagic telangiectasia (HHT) patients undergoing nasal surgery.

Study Design

Retrospective chart review of 55 consecutive HHT patients undergoing a bevacizumab injection for recalcitrant epistaxis. Nineteen patients received local injections to only the SP vasculature, and 36 patients received AP and SP injections.

Methods

Main outcome variable was estimated blood loss during nasal surgery. Independent variables included sex, age, epistaxis severity score, surgical techniques (including laser), and blood pressure parameters (baseline, preinduction, and postintubation).

Results

The mean blood loss in HHT patients receiving SP injections alone was 111 mL, whereas it was 22 mL for those receiving both AP + SP injections. This difference between groups approached statistical significance (P = .075). Blood pressure parameters were similar in both groups with no appreciable difference between intraoperative systolic and mean arterial blood pressure.

Conclusions

The addition of either sublabial or transcutaneous AP injection to the standard SP block markedly reduces blood loss in HHT epistaxis nasal surgery.

Level of Evidence

4. Laryngoscope, 123:2598–2600, 2013
Wrong site surgery in otolaryngology–head and neck surgery
Authors: Liou Tzyy‐Nong , Nussenbaum Brian
Published: May 2013

Objectives/Hypothesis

Wrong site surgery has received high public awareness this past decade, yet discussion specific to otolaryngology is limited.

Study Design

Literature review.

Methods

We searched the MEDLINE database on PubMed from 1980 to 2013 and pursued the citations of key references further. We conducted a review of the literature and public patient safety reports on the scope, root causes, and prevention of wrong site surgery with emphasis on otolaryngology.

Results

A review of the literature reveals that otolaryngology procedures constitute 0.3% to 4.5% of all wrong site surgery events, and wrong site surgery accounts for 4% to 6% of all medical errors in otolaryngology. A significant proportion (9% to 21%) of otolaryngologists reported experiences with wrong site surgery over their career, and the events most frequently resulted in temporary injuries to the patient with few cases of permanent disability or death. Although otolaryngology procedures have similar root causes for wrong site events as other specialties, inverted imaging and ambiguity in site marking are particular challenges. Site‐marking practices are variable among otolaryngologists, as it is not applicable to many otolaryngology procedures, yet these are common procedures that also constitute the majority of wrong site cases reported in otolaryngology.

Conclusions

Future interventions to address these challenges related to otolaryngology–head and neck surgery might involve a standardized protocol to confirm imaging accuracy, a specialty‐ or procedure‐specific checklist, a standardized alternative to site marking when marking is impractical, and other innovations. Evaluation of these interventions is becoming easier given the increasing mandatory reporting of these events that provides more reliable incidence data. Laryngoscope, 124:104–109, 2014
A randomized study of suprastomal stents in laryngotracheoplasty surgery for grade III subglottic stenosis in children
Authors: Preciado Diego
Published: May 2013

Objectives/Hypothesis

Studies comparing the relative effectiveness of suprastomal stents in laryngotracheoplasty surgery are lacking in the literature. The goal of this study was to compare the performance of two widely used short‐term suprastomal stents in open airway surgery.

Study Design

Prospective, randomized study of a single surgeon's outcomes for grade III subglottic stenosis (SGS) in children.

Methods

The open Aboulker Teflon stent versus the cut, closed, soft Silastic Montgomery T‐tube stent for short‐term stenting in double‐stage laryngotracheoplasty (dsLTP) were compared.

Results

Twenty‐four patients were recruited into the study; 12 received an Aboulker (A) stent and 12 a cut, soft, Silastic (S) stent. There was no statistically significant difference in the operation specific decannulation rate between the two stent groups. Patients who received S stents were found to tolerate postoperative feeding better than those with A stents. The median time to decannulate, however, was longer for those receiving S stents (5.5 vs. 3.5 months, P = .02). Furthermore, those receiving S stents had increased need for airway dilation after stent removal (1.75 vs. 0.17 dilations per patient, P = .02) and increased presence of granulation tissue in the airway at the time of stent removal. Multivariate analysis showed the type of stent used independently correlated to time to decannulate (P = .022).

Conclusions

Compared to the Teflon Aboulker stents, closed, soft, Silastic stents are associated with improved feeding in the postoperative period. Their use, however, also correlates with worsened granulation tissue formation and longer time to decannulation in patients undergoing dsLTP for grade III SGS.

Level of Evidence

1b. Laryngoscope, 124:207–213, 2014
Impact of synechiae after endoscopic sinus surgery on long‐term outcomes in chronic rhinosinusitis
Authors: Henriquez Oswaldo A. , Schlosser Rodney J. , Mace Jess C. , Smith Timothy L. , Soler Zachary M.
Published: May 2013

Objectives/Hypothesis

Synechiae are one of the most common unwanted outcomes after endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS). However, there has been scant investigation into the true significance of synechiae formation after ESS. The aim of this study was to evaluate the impact of synechiae formation on health‐related quality of life (HRQoL) outcomes after ESS in patients with CRS.

Study Design

Prospective, multi‐institutional cohort.

Methods

Rhinosinusitis Disability Index (RSDI) and Chronic Sinusitis Survey (CSS) scores were measured in adult patients before and after undergoing ESS for CRS. Differences in HRQoL were evaluated between those who developed sinonasal synechiae and those who did not, controlling for demographic factors, medical comorbidities, and measures of disease severity at baseline.

Results

A total of 286 patients underwent ESS, with 55 (19.2%) developing synechiae in the follow‐up period. Patients developing synechiae reported significantly less improvement on the RSDI total scores (13.5 vs. 21.4, P = 0.008), RSDI physical subscores (5.3 vs. 8.3, P = 0.007), RSDI emotional subscores (2.9 vs. 5.8, P = 0.008), CSS total scores (14.5 vs. 21.2, P = 0.093), and CSS symptom subscores (19.9 vs 30.3, P = 0.069) compared to those who did not develop synechiae postoperatively. These differences persisted even after controlling for baseline differences in disease severity.

Conclusions

Synechiae of the sinonasal cavity commonly occurs following ESS, particularly in those undergoing revision surgeries. Although both groups improve, the degree of HRQoL improvement appears to be less in those who form postoperative synechiae after surgery compared to those who do not.

Level of Evidence

2c. Laryngoscope, 123:2615–2619, 2013
Development of a porous poly(DL‐lactic acid‐co‐glycolic acid)‐based scaffold for mastoid air‐cell regeneration
Authors: Gould Toby W. A. , Birchall John P. , Mallick Ali S. , Alliston Tamara , Lustig Lawrence R. , Shakesheff Kevin M. , Rahman Cheryl V.
Published: May 2013

Objectives/Hypothesis

To develop a porous, biodegradable scaffold for mastoid air‐cell regeneration.

Study Design

In vitro development of a temperature‐sensitive poly(DL‐lactic acid‐co‐glycolic acid)/poly(ethylene glycol) (PLGA/PEG) scaffold tailored for this application.

Methods

Human mastoid bone microstructure and porosity were investigated using micro‐computed tomography. PLGA/PEG‐alginate scaffolds were developed, and scaffold porosity was assessed. Human bone marrow mesenchymal stem cells (hBM‐MSCs) were cultured on the scaffolds in vitro. Scaffolds were loaded with ciprofloxacin, and release of ciprofloxacin over time in vitro was assessed.

Results

Porosity of human mastoid bone was measured at 83% with an average pore size of 1.3 mm. PLGA/PEG‐alginate scaffold porosity ranged from 43% to 78% depending on the alginate bead content. The hBM‐MSCs proliferate on the scaffolds in vitro, and release of ciprofloxacin from the scaffolds was demonstrated over 7 to 10 weeks.

Conclusions

The PLGA/PEG‐alginate scaffolds developed in this study demonstrate similar structural features to human mastoid bone, support cell growth, and display sustained antibiotic release. These scaffolds may be of potential clinical use in mastoid air‐cell regeneration. Further in vivo studies to assess the suitability of PLGA/PEG‐alginate scaffolds for this application are required

Level of Evidence

N/A. Laryngoscope, 123:3156–3161, 2013
Efficient concomitant and remanence field artifact reduction in ultra‐low‐field MRI using a frequency‐space formulation
Authors: Hsu Yi‐Cheng , Vesanen Panu T. , Nieminen Jaakko O. , Zevenhoven Koos C.J. , Dabek Juhani , Parkkonen Lauri , Chern I‐Liang , Ilmoniemi Risto J. , Lin Fa‐Hsuan
Published: May 2013

Purpose

For ultra‐low‐field MRI, the spatial‐encoding magnetic fields generated by gradient coils can have strong concomitant fields leading to prominent image distortion. Additionally, using superconducting magnet to pre‐polarize magnetization can improve the signal‐to‐noise ratio of ultra‐low‐field MRI. Yet the spatially inhomogeneous remanence field due to the permanently trapped flux inside a superconducting pre‐polarizing coil modulates magnetization and causes further image distortion.

Method

We propose a two‐stage frequency–space (f–x) formulation to accurately describe the dynamics of spatially‐encoded magnetization under the influence of concomitant and remanence fields, which allows for correcting image distortion due to concomitant and remanence fields.

Results

Our method is computationally efficient as it uses a combination of the fast Fourier transform algorithm and a linear equation solver. With sufficiently dense discretization in solving the linear equation, the performance of this f–x method was found to be stable among different choices of the regularization parameter and the regularization matrix.

Conclusion

We present this method together with numerical simulations and experimental data to demonstrate how concomitant and remanence field artifacts in ultra‐low‐field MRI can be corrected efficiently. Magn Reson Med 71:955–965, 2014. © 2013 Wiley Periodicals, Inc.
Analysis and correction of gradient nonlinearity bias in apparent diffusion coefficient measurements
Authors: Malyarenko Dariya I. , Ross Brian D. , Chenevert Thomas L.
Published: May 2013

Purpose

Gradient nonlinearity of MRI systems leads to spatially dependent b‐values and consequently high non‐uniformity errors (10–20%) in apparent diffusion coefficient (ADC) measurements over clinically relevant field‐of‐views. This work seeks practical correction procedure that effectively reduces observed ADC bias for media of arbitrary anisotropy in the fewest measurements.

Methods

All‐inclusive bias analysis considers spatial and time‐domain cross‐terms for diffusion and imaging gradients. The proposed correction is based on rotation of the gradient nonlinearity tensor into the diffusion gradient frame where spatial bias of b‐matrix can be approximated by its Euclidean norm. Correction efficiency of the proposed procedure is numerically evaluated for a range of model diffusion tensor anisotropies and orientations.

Results

Spatial dependence of nonlinearity correction terms accounts for the bulk (75–95%) of ADC bias for FA = 0.3–0.9. Residual ADC non‐uniformity errors are amplified for anisotropic diffusion. This approximation obviates need for full diffusion tensor measurement and diagonalization to derive a corrected ADC. Practical scenarios are outlined for implementation of the correction on clinical MRI systems.

Conclusions

The proposed simplified correction algorithm appears sufficient to control ADC non‐uniformity errors in clinical studies using three orthogonal diffusion measurements. The most efficient reduction of ADC bias for anisotropic medium is achieved with non‐lab‐based diffusion gradients. Magn Reson Med 71:1312–1323, 2014. © 2013 Wiley Periodicals, Inc.
Mapping mean and fluctuating velocities by Bayesian multipoint MR velocity encoding‐validation against 3D particle tracking velocimetry
Authors: Knobloch Verena , Binter Christian , Gülan Utku , Sigfridsson Andreas , Holzner Markus , Lüthi Beat , Kozerke Sebastian
Published: May 2013

Purpose

To validate Bayesian multipoint MR velocity encoding against particle tracking velocimetry for measuring velocity vector fields and fluctuating velocities in a realistic aortic model.

Methods

An elastic cast of a human aortic arch equipped with an 80 or 64% stenotic section was driven by a pulsatile pump. Peak velocities and peak turbulent kinetic energies of more than 3 m/s and 1000 J/m3 could be generated. Velocity vector fields and fluctuating velocities were assessed using Bayesian multipoint MR velocity encoding with varying numbers of velocity encoding points and particle tracking velocimetry in the ascending aorta.

Results

Velocities and turbulent kinetic energies measured with 5‐fold k‐t undersampled 10‐point MR velocity encoding and particle tracking velocimetry were found to reveal good correlation with mean differences of −4.8 ± 13.3 cm/s and r2 = 0.98 for velocities and −21.8 ± 53.9 J/m3 and r2 = 0.98 for turbulent kinetic energies, respectively. Three‐dimensional velocity patterns of fast flow downstream of the stenoses and regions of elevated velocity fluctuations were found to agree well.

Conclusion

Accelerated Bayesian multipoint MR velocity encoding has been demonstrated to be accurate for assessing mean and fluctuating velocities against the reference standard particle tracking velocimetry. The MR method holds considerable potential to map velocity vector fields and turbulent kinetic energies in clinically feasible exam times of <15 min. Magn Reson Med 71:1405–1415, 2014. © 2013 Wiley Periodicals, Inc.
Involvement of cathepsins B and L in inflammation and cholesterol trafficking protein NPC2 secretion in macrophages
Authors: Hannaford Jennifer , Guo Hong , Chen Xiaoli
Published: May 2013

Objective

Obesity and its related chronic inflammation are the major risk factors for developing metabolic disturbances. The roles of cathepsin cysteine proteases have been tied to inflammation and atherosclerosis. Cathepsins are important functional links between inflammation, cholesterol metabolism, and atherosclerosis in obesity. NPC2, a lysosomal protein, plays an important role in cholesterol trafficking. The objective of this study was to examine the regulation of cathepsins and NPC2 in adipose tissue and macrophages in obesity and the effect of modifying cathepsin activity in cholesterol metabolism and trafficking in macrophages.

Design and Methods

Cathepsins and NPC2 mRNA expression and protein secretion were detected in obese adipose tissue as well as 3T3‐L1 adipocytes and Raw 264.7 macrophages in response to inflammatory stimuli and cathepsin inhibitors.

Results

It was found that high‐fat diet feeding altered the mRNA and protein expression levels of cathepsins B and L (CtB and CtL) and NPC2 in adipose tissue in mice; the differential regulation of these proteins was observed between adipose depots. In vitro studies showed that TNF‐α reduces intracellular protein levels of CtB, CtL, and NPC2, but increases their secretion in 3T3‐L1 adipocytes. Likewise, LPS stimulated the secretion of CtB and NPC2 in Raw 264.7 macrophages. Using the inhibitors of cathepsin enzymatic activity, it was found that CtB and CtL regulate TNF‐α production, the expression and secretion of NPC2 protein, and the mRNA levels of the genes involved in cholesterol trafficking in macrophages.

Conclusion

These findings suggest that CtB and CtL have a significant involvement in mediating the inflammatory response, in cholesterol trafficking, and in regulating NPC2 secretion.
Pro12Ala variant of the PPARG2 gene increases body mass index: An updated meta‐analysis encompassing 49,092 subjects
Authors: Galbete C. , Toledo E. , Martínez‐González M.A. , Martínez J.A. , Guillén‐Grima F. , Marti A.
Published: May 2013

Objective

The peroxisome proliferator‐activated receptor gamma 2 (PPARG2) gene has been intensively studied with relation to obesity and metabolic disorders. Indeed, a large number of studies assessing the association between the PPARG2 polymorphism Pro12Ala (rs1801282) and body mass index (BMI) have been published with some controversial results. In this meta‐analysis, the effects of Pro12Ala polymorphism of the PPARG2 gene on BMI were investigated.

Design and Methods

Externally published data were collected and we included our own novel data from a study in the elderly participants (>55 years) of a Mediterranean cohort, the SUN (“Seguimiento Universidad de Navarra”) Project (n = 972). A total of 75 independent studies with 49,092 subjects (39,806 with the genotype Pro12Pro and 9,286 carrier subjects of the Ala allele) were included.

Results

The meta‐analysis revealed a higher BMI with an overall estimation of +0.065 kg/m2 (95%CI = 0.026‐0.103, P = 0.001) for homo‐/heterozygous carriers of the Ala allele of the PPARG2 gene in comparison to non‐carriers. The analysis also showed that there was heterogeneity (P for heterogeneity <0.001), but funnel plots did not suggest apparent publication bias. Furthermore, the association between the Pro12Ala polymorphism of the PPARG2 gene and increased BMI was stronger in Caucasian. Thus, carriers of the Ala allele had significantly higher BMI than non‐carriers in a subsample of 6,528 Caucasian male subjects (standardized mean difference = 0.090, 95%CI=0.032‐0.148, P = 0.002, P for heterogeneity = 0.121).

Conclusion

This updated meta‐analysis showed that carriers of the Ala12 allele of the PPARG2 gene had a higher average BMI.
Advantages of percent weight loss as a method of reporting weight loss after Roux‐en‐Y gastric bypass
Authors: Hatoum Ida J. , Kaplan Lee M.
Published: May 2013

Objective

Although Roux‐en‐Y gastric bypass (RYGB) is an effective treatment for severe obesity, weight loss (WL) after this operation is highly variable. Accurate predictors of outcome would thus be useful in identifying those patients who would most benefit from this invasive therapy. WL has been characterized using several different metrics, including the number of BMI units lost (ΔBMI), percent baseline WL (%WL), and percent excess body WL (%EBWL). To identify clinically relevant predictors most sensitively, it is necessary to avoid confounding by other factors, including preoperative BMI (pBMI), the strongest known predictor of RYGB‐induced WL.

Design and Methods

To determine the WL measure least associated with pBMI, outcomes of 846 patients undergoing RYGB were analyzed.

Results

Patients in this cohort had an average pBMI of 50.0 kg/m2 at baseline. At weight nadir, they lost an average 19.4 kg/m2, 38.7% WL, and 81.2% EBWL. pBMI was strongly and positively associated with ΔBMI at both 1 year (r = 0.56, P = 4.7 × 10−51) and nadir (r = 0.58, P = 2.8 × 10−77) and strongly but negatively associated with %EBWL at 1 year (r = −0.52, P = 3.8 × 10−44) and nadir (r = −0.45, P = 7.2×10−43). In contrast, pBMI was not significantly associated with %WL at 1 year (r = 0.04, P = 0.33) and only weakly associated at nadir (r = 0.13, P = 0.0002).

Conclusions

Of the metrics examined, %WL is the parameter describing WL after RYGB least influenced by pBMI. It thus improves comparison of WL outcomes across studies of patients undergoing surgery and facilitates the most sensitive identification of novel predictors of surgery‐induced WL. We therefore is recommend that %WL be adopted more broadly in reporting weight loss after RYGB.
Pharmacological inhibition of diacylglycerol acyltransferase 1 reduces body weight and modulates gut peptide release—Potential insight into mechanism of action
Authors: Liu Jinqi , Gorski Judith N. , Gold Stephen J. , Chen Dunlu , Chen Shirley , Forrest Gail , Itoh Yoshiki , Marsh Donald J. , McLaren David G. , Shen Zhu , Sonatore Lisa , Carballo‐Jane Ester , Craw Stephanie , Guan Xiaoming , Karanam Bindhu , Sakaki Junichi , Szeto Daphne , Tong Xinchun , Xiao Jianying , Yoshimoto Ryo , Yu Hong , Roddy Thomas P. , Balkovec James , Pinto Shirly
Published: May 2013

Objective

Investigation was conducted to understand the mechanism of action of diacylglycerol acyltransferase 1 (DGAT1) using small molecules DGAT1 inhibitors, compounds K and L.

Design and Methods

Biochemical and stable‐label tracer approaches were applied to interrogate the functional activities of compounds K and L on TG synthesis and changes of carbon flow. Energy homeostasis and gut peptide release upon DGAT1 inhibition was conducted in mouse and dog models.

Results

Compounds K and L, dose‐dependently inhibits post‐prandial TG excursion in mouse and dog models. Weight loss studies in WT and Dgat1‐/‐ mice, confirmed that the effects of compound K on body weight loss is mechanism‐based. Compounds K and L altered incretin peptide release following oral fat challenge. Immunohistochemical studies with intestinal tissues demonstrate lack of detectable DGAT1 immunoreactivity in enteroendocrine cells. Furthermore, 13C‐fatty acid tracing studies indicate that compound K inhibition of DGAT1 increased the production of phosphatidyl choline (PC).

Conclusion

Treatment with DGAT1 inhibitors improves lipid metabolism and body weight. DGAT1 inhibition leads to enhanced PC production via alternative carbon channeling. Immunohistological studies suggest that DGAT1 inhibitor's effects on plasma gut peptide levels are likely via an indirect mechanism. Overall these data indicate a translational potential towards the clinic.
Ectopic fat and adipokines in metabolically benign overweight/obese women: The kronos early estrogen prevention study
Authors: Ogorodnikova Alexandra D. , Khan Unab I. , McGinn Aileen P. , Zeb Irfan , Budoff Matthew J. , Harman S.M. , Miller Virginia M. , Brinton Eliot A. , Manson JoAnn E. , Hodis Howard N. , Merriam George R. , Cedars Marcelle I. , Taylor Hugh S. , Naftolin Frederick , Lobo Rogerio A. , Santoro Nanette , Wildman Rachel P.
Published: May 2013

Objective

It is unclear why despite a comparable cardiometabolic risk profile, “metabolically benign” overweight/obese individuals show an elevated risk of cardiovascular disease compared to normal weight individuals.

Design and Methods

In cross‐sectional analyses, we compared levels of ectopic fat (epicardial, pericardial, and hepatic fat) and adipokines (leptin, soluble leptin receptor, and high molecular weight [HMW] adiponectin) among metabolically benign (MBO) and at‐risk overweight/obese (ARO), and metabolically benign normal weight (MBNW) women, screened for the Kronos Early Estrogen Prevention Study. We defined “metabolically benign” with ≤ 1, and “at‐risk” with ≥2 components of the metabolic syndrome.

Results

Compared to MBO women, ARO women had significantly elevated odds of being in the top tertile of epicardial fat (OR: 1.76, 95% CI: 1.04‐2.99), hepatic fat (OR: 1.90, 95% CI:1.12‐3.24) and leptin (OR: 2.15, 95% CI: 1.23‐3.76), and the bottom tertile of HMW‐adiponectin (OR: 2.90, 95% CI: 1.62‐5.19). Compared to MBNW women, MBO women had significantly higher odds of being in the top tertile of epicardial fat (OR: 5.17, 95% CI: 3.22‐8.29), pericardial fat (OR: 9.27, 95% CI: 5.52‐15.56) and hepatic fat (OR: 2.72, 95% CI: 1.77‐4.19) and the bottom tertile of HMW adiponectin levels (OR: 2.51, 95% CI: 1.60‐3.94).

Conclusions

Levels of ectopic fat and the adverse adipokine profile increase on a continuum of BMI, suggesting that the metabolically benign phenotype may be a transient state.
Laparoscopic sleeve gastrectomy differentially affects serum concentrations of FGF‐19 and FGF‐21 in morbidly obese subjects
Authors: Haluzíková D. , Lacinová Z. , Kaválková P. , Drápalová J. , Křížová J. , Bártlová M. , Mráz M. , Petr T. , Vítek L. , Kasalický M. , Haluzík M.
Published: May 2013

Objective

Fibroblast growth factor (FGF)‐19 and FGF‐21 are novel metabolic regulators that improve insulin resistance and obesity in rodents. The aim of the study was to assess the effects of laparoscopic sleeve gastrectomy (LSG) on serum concentrations of FGF‐19 and FGF‐21 along with circulating bile acids and other relevant hormonal and biochemical parameters.

Design and Methods

Seventeen females with obesity undergoing LSG and 15 lean healthy females were included into the study. Anthropometric and biochemical parameters, serum concentrations of FGF‐19 and ‐21, insulin, adiponectin, leptin, C‐reactive protein, resistin, amylin (total), ghrelin (active), glucagon‐like peptide 1 (GLP‐1, active), glucose‐dependent insulinotropic peptide (GIP, total), peptide YY (PYY, total), pancreatic polypeptide (PP), and bile acids, and mRNA expression of selected adipokines and inflammatory markers in bioptic samples of subcutaneous fat were assessed at baseline and 6, 12, and 24 months after LSG.

Results

LSG markedly decreased body weight, BMI, waist circumference, and insulin levels and improved systemic inflammation and lipid levels. FGF‐19 concentrations increased and FGF‐21 concentrations decreased after LSG along with increased adiponectin and decreased leptin, amylin, and ghrelin levels. GLP‐1, GIP, PP, and circulating bile acids were not affected by LSG. PYY decreased significantly 24 months after surgery only. mRNA expression analysis in subcutaneous fat showed markedly reduced proinflammatory state.

Conclusions

Our results indicate that increased FGF‐19 and decreased ghrelin concentrations could have partially contributed to the improvement of systemic inflammation and some metabolic parameters after LSG, while changes of FGF‐21 are rather secondary because of weight loss.
Metabolic and endocrine correlates of cognitive function in healthy young women
Authors: Bove R.M. , Brick D.J. , Healy B.C. , Mancuso S.M. , Gerweck A.V. , Bredella M.A. , Sherman J.C. , Miller K.K.
Published: May 2013

Objective

Obesity has been associated with cognitive decline in longitudinal studies of older individuals. We hypothesized that the cognitive sequelae of obesity may be detectable in the reproductive years. In addition, we explored the hypothesis that these associations may be mediated by the hormonal milieu.

Design and Methods

Of 49 young healthy lean and overweight women aged 20‐45, we investigated the association between performance on a battery of cognitive tests, body composition parameters [body mass index, total fat, abdominal (visceral, subcutaneous, and total) adipose tissue, and muscle], and hormone levels (insulin, adiponectin, leptin, insulin‐like growth factor 1 (IGF‐1), estrogen, testosterone, and vitamin D).

Results

We found a significant negative association between both visceral adiposity and muscle, and performance in the domain of verbal learning and memory, after controlling for age and education. Other body composition parameters showed similar trends (0.05 < P < 0.10). Additionally, the degree of insulin resistance was negatively associated with executive function domain. None of the associations between the other hormones examined (adipokines, IGF‐1, gonadal hormones, and vitamin D) and cognitive function were significant.

Conclusion

These preliminary findings suggest a possible association between obesity and cognitive function in healthy young women of reproductive age. More research is warranted into the potential modulatory effect of insulin resistance on this association.
Microstructure and properties of styrene‐butadiene rubber based nanocomposites prepared from an aminosilane modified synthetic lamellar nanofiller
Authors: Dal Pont Kevin , Gérard Jean‐François , Espuche Eliane
Published: May 2013

In this work, a novel nanocomposite series based on styrene‐butadiene rubber (SBR latex) and alpha‐zirconium phosphate(α‐ZrP) lamellar nanofillers is successfully prepared. The α‐ZrP lamellar filler is modified at the cation exchange capacity by γ‐aminopropyltrimethoxysilane and the filler surface modification is first discussed. A significant improvement of the mechanical properties is obtained by using the surface modified nanofillers. However, no modification of the gas barrier properties is observed. The impact of addition of bis(triethoxysilylpropyl)tetrasulfide (TESPT) as coupling agent in the system is discussed on the nanofiller dispersion state and on the filler–matrix interfacial bonding. Simultaneous use of modified nanofillers and TESPT coupling agent is found out with extraordinary reinforcing effects on both mechanical and gas barrier properties and the key factors at the origin of the improvement of these properties are identified. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1051–1059
Development of a label‐free LC‐MS/MS strategy to approach the identification of candidate protein biomarkers of disease recurrence in prostate cancer patients in a clinical trial of combined hormone and radiation therapy
Authors: Morrissey Brian , O'Shea Carmel , Armstrong John , Rooney Cathy , Staunton Lisa , Sheehan Martina , Shannon Aoife M. , Pennington Stephen R.
Published: May 2013

Purpose

Combined hormone and radiation therapy (CHRT) is one of the principle curative regimes for localised prostate cancer (PCa). Following treatment, many patients subsequently experience disease recurrence however; current diagnostics tests fail to predict the onset of disease recurrence. Biomarkers that address this issue would be of significant advantage.

Experimental design

Label‐free LC‐MS/MS for protein biomarker discovery and MRM for targeted confirmation were applied to patient serum samples accrued in a non‐interventional clinical trial of CHRT.

Results

Analysis of time‐matched patient samples from a patient with disease recurrence compared with a time match disease‐free individual supported the identification of 287 proteins. Of these, 141 proteins were quantified, 95 proteins changed in their expression (P ≤ 0.05 and ≥1.5‐fold change) and of these 16 were selected for MRM confirmation. The protein expression changes observed in the label‐free LC‐MS/MS and MRM analysis were found to be highly correlated (R2 = 0.85).

Conclusions and clinical relevance

The establishment of a clinical trial to support the acquisition of samples and development of a pipeline for MS‐based biomarker discovery and validation should contribute to the identification of a serum protein signature to predict or monitor the outcome of treatment of patients with PCa.
Electronic structures of ternary‐layered semiconductor TlGaSe2 investigated by photoemission spectroscopy
Authors: Motonami Satoru , Mimura Kojiro , Shim YongGu , Wakita Kazuki , Sato Hitoshi , Utsumi Yuki , Ueda Shigenori , Nakatake Masashi , Shimada Kenya , Taguchi Yukihiro , Kobayashi Keisuke , Namatame Hirofumi , Taniguchi Masaki , Orudzhev Guseyn , Mamedov Nazim
Published: May 2013

Electronic structures of the ternary‐layered semiconductor TlGaSe2 have been investigated by hard and soft X‐ray photoemission spectroscopies (HAXPES and SXPES). The spectral shape of all core levels obtained from HAXPES and SXPES can be represented by a symmetric Lorentzian, reflecting the semiconducting nature of TlGaSe2. Peak positions of the same bulk components, obtained from HAXPES and SXPES, are almost the same. This suggests that the recoil effect is ignorable for TlGaSe2 and that the HAXPES spectra of this material provide us the information on the intrinsic bulk electronic structures. The valence‐band HAXPES spectrum is composed of two main features and is well reproduced by the theoretical calculation. The estimated value of 2.0 eV for the energy gap is consistent with the results from the optical measurements. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of Cu2SnS3 thin films by sulfurization of evaporated Cu‐Sn precursors for solar cells
Authors: Aihara Naoya , Araki Hideaki , Takeuchi Akiko , Jimbo Kazuo , Katagiri Hironori
Published: May 2013

The ternary compound semiconductor Cu2SnS3 (CTS) is formed from non‐toxic materials that are abundant in Earth's crust and other low‐cost elements. CTS has also been reported to a band gap energy range of 0.93–1.77 eV and an absorption coefficient of 1.0×104 cm–1. Consequently, CTS is a potential material for the p‐type absorber layer of thin film solar cells. In this study, we examined the dependence of the optical, electrical and photovoltaic properties of CTS thin films on the Cu/Sn composition ratio. CTS thin films were fabricated by sulfurizing evaporated Cu‐Sn precursors with different Cu/Sn composition ratios at 560 °C for 2 h in a N2 atmosphere and sulfur vapor. The Cu/Sn composition ratios of the sulfurized films were determined to be 1.6–2.5 by X‐ray fluorescence. The solar cell comprising a CTS thin film with a Cu/Sn composition ratio of 1.77 exhibited the best performance among the cells examined, an open‐circuit voltage of 242 mV, a short‐circuit current density of 28.9 mA/cm2, a fill factor of 41.7% and a conversion efficiency of 2.92% were obtained. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)