bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of full‐thickness cartilage defects in knee osteoarthritis (OA) incidence and progression: Data from the OA Initiative
Authors: Everhart Joshua S. , Abouljoud Moneer M. , Flanigan David C. 
Published: September 2018

ABSTRACTThe purpose of this study is to determine whether full‐thickness tibiofemoral cartilage defects are predictive of incident radiographic OA, progression of radiographic OA, and progression to severe radiographic OA. Participants in the OA Initiative (n = 1317, 38.1% male, mean age 60.9 years SD 9.2) with baseline MRIs and Kellgren–Lawrence (KL) OA grade 0–3 (none to moderate OA) were included. All participants had follow‐up radiographs at mean 4.9 years (max 8.0). The effect of full‐thickness defect presence, size, and location on risk of incident OA (KL grade 2+), overall progression of OA (increase in KL grade 1+ points), or compartment‐specific OA progression was assessed with Cox proportional hazards modeling with adjustment for demographic factors, weight, and knee alignment. The yearly incidence of tibiofemoral OA was 0.3% (CI 0.2–0.4%); defect presence, size, and location were not associated with incident OA risk. The yearly rate of OA progression was 3.8% in participants without tibiofemoral full‐thickness defects, 6.7% with medial defects, and 6.3% with lateral defects. Medial bipolar (kissing) lesions were an independent risk factor for OA progression as well as medial compartment progression. Lateral tibial‐sided full‐thickness defects increased risk of lateral progression (increase in lateral OARSI grade). In older adults, isolated full‐thickness cartilage defects do not increase short‐term risk of incident OA. However, in the setting of preexisting mild or moderate OA, medial bipolar (kissing) defects increase risk of overall OA progression (KL grade) as well as progression of medial compartment OA. Lateral tibial defects increase risk of lateral compartment OA progression. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
High muscle co‐contraction does not result in high joint forces during gait in anterior cruciate ligament deficient knees
Authors: Khandha Ashutosh , Manal Kurt , Capin Jacob , Wellsandt Elizabeth , Marmon Adam , Snyder‐Mackler Lynn , Buchanan Thomas S. 
Published: September 2018

ABSTRACTThe mechanism of knee osteoarthritis development after anterior cruciate ligament injuries is poorly understood. The objective of this study was to evaluate knee gait variables, muscle co‐contraction indices and knee joint loading in young subjects with anterior cruciate ligament deficiency (ACLD, n = 36), versus control subjects (n = 12). A validated, electromyography‐informed model was used to estimate joint loading. For the involved limb of ACLD subjects versus control, muscle co‐contraction indices were higher for the medial (p = 0.018, effect size = 0.93) and lateral (p = 0.028, effect size = 0.83) agonist–antagonist muscle pairs. Despite higher muscle co‐contraction, medial compartment contact force was lower for the involved limb, compared to both the uninvolved limb (mean difference = 0.39 body weight, p = 0.009, effect size = 0.70) as well as the control limb (mean difference = 0.57 body weight, p = 0.007, effect size = 1.14). Similar observations were made for total contact force. For involved versus uninvolved limb, the ACLD group demonstrated lower vertical ground reaction force (mean difference = 0.08 body weight, p = 0.010, effect size = 0.70) and knee flexion moment (mean difference = 1.32% body weight * height, p = 0.003, effect size = 0.76), during weight acceptance. These results indicate that high muscle co‐contraction does not always result in high knee joint loading, which is thought to be associated with knee osteoarthritis. Long‐term follow‐up is required to evaluate how gait alterations progress in non‐osteoarthritic versus osteoarthritic subjects. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Intranasal Corticosteroids Do Not Lead to Ocular Changes: A Systematic Review and Meta‐analysis
Authors: Valenzuela Carla V. , Liu James C. , Vila Peter M. , Simon Laura , Doering Michelle , Lieu Judith E. C. 
Published: September 2018

ObjectivesThe safety and efficacy of intranasal corticosteroids (INCS) are well established, but there remains apprehension that INCS could lead to systemic side effects, as with oral steroids. The objective of this systematic review was to assess whether the use of INCS lead to increased intraocular pressure (IOP) above 20 mm Hg, glaucoma, or formation of posterior subcapsular cataracts in adult patients with rhinitis.MethodsTwo medical librarians searched the published literature for records discussing the use of “nasal steroids” in “rhinitis” and their effect on “intraocular pressure,” “cataracts,” or “glaucoma.”ResultsA total of 484 studies were identified, and 10 randomized controlled trials met our inclusion criteria. Meta‐analysis of 2,226 patients revealed that the relative risk of elevated IOP in those who received INCS was 2.24 (95% confidence interval [CI]: 0.68 to 7.34) compared to placebo. The absolute increased incidence of elevated IOP in patients using INCS compared to placebo was 0.8% (95% CI: 0% to 1.6%). There were zero cases of glaucoma in both placebo and INCS groups at 12 months. The absolute increased incidence of developing a posterior subcapsular cataract was 0.02% (95% CI: −0.3% to 0.4%).ConclusionsUse of INCS is not associated with a significant risk of elevating IOP or developing a posterior subcapsular cataract in patients with allergic rhinitis. Presence of glaucoma, however, is the real clinical adverse event of concern. There were zero reported cases of glaucoma at 12 months. Future studies should formally evaluate for glaucoma rather than use IOP measures as a surrogate. Laryngoscope, 129:6–12, 2019
Long‐term outcomes of cartilage‐buttressed T‐tube tympanoplasty for prolonged middle ear ventilation
Authors: Zuniga Steven A. , Larner Sean , Souza David M. , Khan Andleeb , Hillman Todd A. , Chen Douglas A. 
Published: September 2018

Objectives/HypothesisTo report on the safety and efficacy of cartilage‐buttressed T‐tube tympanoplasty for long‐term middle ear ventilation, specifically by examining duration of tube survival, as well as adverse events associated with prolonged middle ear intubation, including persistent tympanic membrane perforation.Study DesignRetrospective case series of patients undergoing cartilage‐buttressed T‐tube tympanoplasty between January 2005 and December 2016 in a tertiary‐care neurotology private practice.MethodsPatients who underwent cartilage T‐tube tympanoplasty with complete pre‐ and postoperative audiometric data and a minimum follow‐up duration of 12 months were analyzed. T‐tube survival and adverse events including persistent tympanic membrane perforation were recorded and compared to published data for other long‐term middle ear ventilation techniques.ResultsThe study cohort included 72 cartilage‐buttressed T‐tube tympanoplasties in 68 patients. Median tube survival was 34 months (range, 2–131 months). Incidence of persistent tympanic membrane perforation (n = 1) was 1.4%ConclusionsCartilage‐buttressed T‐tube tympanoplasty is a safe and effective means of accomplishing long‐term middle ear ventilation with a considerably lower rate of persistent tympanic membrane perforation as compared to alternative methods of prolonged middle ear ventilation.Level of Evidence4 Laryngoscope, 129:203–208, 2019
Role of Skin Layers on Mechanical Properties and Supercontraction of Spider Dragline Silk Fiber
Authors: Yazawa Kenjiro , Malay Ali D. , Masunaga Hiroyasu , Numata Keiji 
Published: September 2018

AbstractSpider dragline silk is a composite biopolymer that harbors extraordinary mechanical characteristics, and consists of a hierarchically arranged protein core surrounded by outer “skin” layers. However, the contribution of the successive fiber layers on material properties has not been well defined. Here, the influence of the different components on the physicochemical and mechanical properties of dragline is investigated. The crystal structure and the mechanical properties are not changed significantly after the removal of skin constituents, indicating that the core region of dragline silk fibers determines the structural and mechanical properties. Furthermore, the outer layers have little influence on supercontraction, suggesting they do not function as protection against the penetration of water molecules. On the other hand, the outer layers offer some protection against protease digestion. The present study provides insight into how the function and structure of silk fibers are modulated and facilitates the design of silk‐inspired functional materials.
Placebo and nocebo responses in other movement disorders besides Parkinson's disease: How much do we know?
Authors: Ferreira Joaquim J. , Trenkwalder Claudia , Mestre Tiago A. 
Published: September 2018

ABSTRACTAmong movement disorders and medicine in general, PD is one of the conditions for which there is a greater knowledge of the placebo and nocebo responses. In other movement disorders, the knowledge of placebo and nocebo responses is less. An advance in this field is expected to contribute to a better understanding of the nature of a therapeutic benefit in clinical research and clinical practice, and mechanisms of placebo and nocebo. We conducted a review on placebo and nocebo responses in other movement disorders besides PD by primarily examining meta‐analyses of clinical trials assessing specifically the placebo and/or nocebo responses. Second, we examined both efficacy and safety results of a placebo arm in pivotal placebo‐controlled trials for the different movement disorders. RLS is the movement disorder for which the most data exist, followed by tic disorders and Huntington's disease. Data available in other conditions document a placebo response in a varied phenomenology. We found different placebo responses according to clinical domains assessed, type of outcomes used for the same clinical domain, and modes of treatment administration, including rehabilitation and surgical interventions. Data on the nocebo response were very scarce. Although the data available are limited, RLS has the better documentation of placebo and nocebo responses. In contrast, atypical parkinsonisms are the group of movement disorders with the least knowledge. The clinical entities with a more robust placebo response are those that have the most beneficial available symptomatic treatments. © 2018 International Parkinson and Movement Disorder Society
Symplectomorphic registration with phase space regularization by entropy spectrum pathways
Authors: Galinsky Vitaly L. , Frank Lawrence R. 
Published: September 2018

PurposeThe ability to register image data to a common coordinate system is a critical feature of virtually all imaging studies. However, in spite of the abundance of literature on the subject and the existence of several variants of registration algorithms, their practical utility remains problematic, as commonly acknowledged even by developers of these methods.MethodsA new registration method is presented that utilizes a Hamiltonian formalism and constructs registration as a sequence of symplectomorphic maps in conjunction with a novel phase space regularization. For validation of the framework a panel of deformations expressed in analytical form is developed that includes deformations based on known physical processes in MRI and reproduces various distortions and artifacts typically present in images collected using these different MRI modalities.ResultsThe method is demonstrated on the three different magnetic resonance imaging (MRI) modalities by mapping between high resolution anatomical (HRA) volumes, medium resolution diffusion weighted MRI (DW‐MRI) and HRA volumes, and low resolution functional MRI (fMRI) and HRA volumes.ConclusionsThe method has shown an excellent performance and the panel of deformations was instrumental to quantify its repeatability and reproducibility in comparison to several available alternative approaches.
Compressed sensing acceleration of biexponential 3D‐T1ρrelaxation mapping of knee cartilage
Authors: Zibetti Marcelo V. W. , Sharafi Azadeh , Otazo Ricardo , Regatte Ravinder R 
Published: September 2018

PurposeUse compressed sensing (CS) for 3D biexponential spin‐lattice relaxation time in the rotating frame (T1ρ) mapping of knee cartilage, reducing the total scan time and maintaining the quality of estimated biexponential T1ρparameters (short and long relaxation times and corresponding fractions) comparable to fully sampled scans.MethodsFully sampled 3D‐T1ρ‐weighted data sets were retrospectively undersampled by factors 2–10. CS reconstruction using 12 different sparsifying transforms were compared for biexponential T1ρ‐mapping of knee cartilage, including temporal and spatial wavelets and finite differences, dictionary from principal component analysis (PCA), k‐means singular value decomposition (K‐SVD), exponential decay models, and also low rank and low rank plus sparse models. Synthetic phantom (N = 6) and in vivo human knee cartilage data sets (N = 7) were included in the experiments. Spatial filtering before biexponential T1ρparameter estimation was also tested.ResultsMost CS methods performed satisfactorily for an acceleration factor (AF) of 2, with relative median normalized absolute deviation (MNAD) around 10%. Some sparsifying transforms, such as low rank with spatial finite difference (L + S SFD), spatiotemporal finite difference (STFD), and exponential dictionaries (EXP) significantly improved this performance, reaching MNAD below 15% with AF up to 10, when spatial filtering was used.ConclusionAccelerating biexponential 3D‐T1ρmapping of knee cartilage with CS is feasible. The best results were obtained by STFD, EXP, and L + S SFD regularizers combined with spatial prefiltering. These 3 CS methods performed satisfactorily on synthetic phantom as well as in vivo knee cartilage for AFs up to 10, with median error below 15%.
Non‐contrast enhanced simultaneous 3D whole‐heart bright‐blood pulmonary veins visualization and black‐blood quantification of atrial wall thickness
Authors: Ginami Giulia , Lòpez Karina , Mukherjee Rahul K. , Neji Radhouene , Munoz Camila , Roujol Sébastien , Mountney Peter , Razavi Reza , Botnar René M. , Prieto Claudia 
Published: September 2018

PurposePre‐interventional assessment of atrial wall thickness (AWT) and of subject‐specific variations in the anatomy of the pulmonary veins may affect the success rate of RF ablation procedures for the treatment of atrial fibrillation (AF). This study introduces a novel non‐contrast enhanced 3D whole‐heart sequence providing simultaneous information on the cardiac anatomy—including both the arterial and the venous system—(bright‐blood volume) and AWT (black‐blood volume).MethodsThe proposed MT‐prepared bright‐blood and black‐blood phase sensitive inversion recovery (PSIR) BOOST framework acquires 2 differently weighted bright‐blood volumes in an interleaved fashion. The 2 data sets are then combined in a PSIR‐like reconstruction to obtain a complementary black‐blood volume for atrial wall visualization. Image‐based navigation and non‐rigid respiratory motion correction are exploited for 100% scan efficiency and predictable acquisition time. The proposed approach was evaluated in 11 healthy subjects and 4 patients with AF scheduled for RF ablation.ResultsImproved depiction of the cardiac venous system was obtained in comparison to a T2‐prepared BOOST implementation, and quantified AWT was shown to be in good agreement with previously reported measurements obtained in healthy subjects (right atrium AWT: 2.54 ± 0.87 mm, left atrium AWT: 2.51 ± 0.61 mm). Feasibility for MT‐prepared BOOST acquisitions in patients with AF was demonstrated.ConclusionThe proposed motion‐corrected MT‐prepared BOOST sequence provides simultaneous non‐contrast pulmonary vein depiction as well as black‐blood visualization of atrial walls. The proposed sequence has a large spectrum of potential clinical applications and further validation in patients is warranted.
Segmentation of left ventricle in late gadolinium enhanced MRI through 2D‐4D registration for infarct localization in 3D patient‐specific left ventricular model
Authors: Leong Chen Onn , Lim Einly , Tan Li Kuo , Abdul Aziz Yang Faridah , Sridhar Ganiga Srinivasaiah , Socrates Dokos , Chee Kok Han , Lee Zhen‐Vin , Liew Yih Miin 
Published: September 2018

PurposeTo evaluate a 2D‐4D registration‐cum‐segmentation framework for the delineation of left ventricle (LV) in late gadolinium enhanced (LGE) MRI and for the localization of infarcts in patient‐specific 3D LV models.MethodsA 3‐step framework was proposed, consisting of: (1) 3D LV model reconstruction from motion‐corrected 4D cine‐MRI; (2) Registration of 2D LGE‐MRI with 4D cine‐MRI; (3) LV contour extraction from the intersection of LGE slices with the LV model. The framework was evaluated against cardiac MRI data from 27 patients scanned within 6 months after acute myocardial infarction. We compared the use of local Pearson's correlation (LPC) and normalized mutual information (NMI) as similarity measures for the registration. The use of 2 and 6 long‐axis (LA) cine‐MRI scans was also compared. The accuracy of the framework was evaluated using manual segmentation, and the interobserver variability of the scar volume derived from the segmented LV was determined using Bland‐Altman analysis.ResultsLPC outperformed NMI as a similarity measure for the proposed framework using 6 LA scans, with Hausdorrf distance (HD) of 1.19 ± 0.53 mm versus 1.51 ± 2.01 mm (endocardial) and 1.21 ± 0.48 mm versus 1.46 ± 1.78 mm (epicardial), respectively. Segmentation using 2 LA scans was comparable to 6 LA scans with a HD of 1.23 ± 0.70 mm (endocardial) and 1.25 ± 0.74 mm (epicardial). The framework yielded a lower interobserver variability in scar volumes compared with manual segmentation.ConclusionThe framework showed high accuracy and robustness in delineating LV in LGE‐MRI and allowed for bidirectional mapping of information between LGE‐ and cine‐MRI scans, crucial in personalized model studies for treatment planning.
Investigation of analysis methods for hyperpolarized 13C‐pyruvate metabolic MRI in prostate cancer patients
Authors: Larson Peder E. Z. , Chen Hsin‐Yu , Gordon Jeremy W. , Korn Natalie , Maidens John , Arcak Murat , Tang Shuyu , Criekinge Mark , Carvajal Lucas , Mammoli Daniele , Bok Robert , Aggarwal Rahul , Ferrone Marcus , Slater James B. , Nelson Sarah J. , Kurhanewicz John , Vigneron Daniel B. 
Published: September 2018

MRI using hyperpolarized (HP) carbon‐13 pyruvate is being investigated in clinical trials to provide non‐invasive measurements of metabolism for cancer and cardiac imaging. In this project, we applied HP [1‐13C]pyruvate dynamic MRI in prostate cancer to measure the conversion from pyruvate to lactate, which is expected to increase in aggressive cancers. The goal of this work was to develop and test analysis methods for improved quantification of this metabolic conversion.In this work, we compared specialized kinetic modeling methods to estimate the pyruvate‐to‐lactate conversion rate, kPL, as well as the lactate‐to‐pyruvate area‐under‐curve (AUC) ratio. The kinetic modeling included an “inputless” method requiring no assumptions regarding the input function, as well as a method incorporating bolus characteristics in the fitting. These were first evaluated with simulated data designed to match human prostate data, where we examined the expected sensitivity of metabolism quantification to variations in kPL, signal‐to‐noise ratio (SNR), bolus characteristics, relaxation rates, and B1 variability. They were then applied to 17 prostate cancer patient datasets.The simulations indicated that the inputless method with fixed relaxation rates provided high expected accuracy with no sensitivity to bolus characteristics. The AUC ratio showed an undesired strong sensitivity to bolus variations. Fitting the input function as well did not improve accuracy over the inputless method. In vivo results showed qualitatively accurate kPL maps with inputless fitting. The AUC ratio was sensitive to bolus delivery variations. Fitting with the input function showed high variability in parameter maps.Overall, we found the inputless kPL fitting method to be a simple, robust approach for quantification of metabolic conversion following HP [1‐13C]pyruvate injection in human prostate cancer studies. This study also provided initial ranges of HP [1‐13C]pyruvate parameters (SNR, kPL, bolus characteristics) in the human prostate.
ABA‐mediated regulation of stomatal density is OST1‐independent
Authors: Jalakas Pirko , Merilo Ebe , Kollist Hannes , Brosché Mikael 
Published: September 2018

AbstractStomata, small pores on the surfaces of leaves formed by a pair of guard cells, adapt rapidly to changes in the environment by adjusting the aperture width. As a long‐term response, the number of stomata is regulated during stomatal development. The hormone abscisic acid (ABA) regulates both processes. In ABA mediated guard cell signaling the protein kinase OPEN STOMATA1 (OST1) has a central role, as stomatal closure in the ost1 mutant is impaired in response to ABA and to different environmental stimuli. We aimed to dissect the contribution of different ABA‐related regulatory mechanisms in determining stomatal conductance, a combination of stomatal density and aperture width, and crossed the ost1 mutant with mutants that either decreased (aba3) or increased (cyp707a1/a3) the concentration of ABA in plants. The double mutant ost1 aba3 had higher stomatal conductance than either parent due to a combination of increased stomatal aperture width and higher stomatal density. In the triple mutant ost1 cyp707a1/a3, stomatal conductance was significantly lower compared to ost1‐3 due to lower stomatal density. Further characterization of the single, double and triple mutants showed that responses to treatments that lead to stomatal closure were impaired in ost1 as well as ost1 aba3 and ost1 cyp707a1/a3 mutants, supporting a critical role for OST1 in stomatal aperture regulation. On the basis of our results, we suggest that two signaling pathways regulate water flux from leaves, that is, stomatal conductance: an ABA‐dependent pathway that determines stomatal density independent of OST1; and an OST1‐dependent pathway that regulates rapid changes in stomatal aperture.
Static and dynamic scaling behavior of a polymer melt model with triple‐well bending potential
Authors: Jabbari‐Farouji Sara 
Published: September 2018

ABSTRACTWe perform molecular‐dynamics simulations for polymer melts of the coarse‐grained poly(vinyl alcohol) model that crystallizes upon slow cooling. To establish the properties of its high temperature, liquid state as a reference point, we characterize in detail the structural features of equilibrated polymer melts with chain lengths5 ≤N≤ 1000at a temperature slightly above their crystallization temperature. We find that the conformations of sufficiently long polymers withN> 50 obey essentially the Flory's ideality hypothesis. The chain length dependence of the end‐to‐end distance and the gyration radius follow the scaling predictions of ideal chains and the probability distributions of the end‐to‐end distance, and form factors are in good agreement with those of ideal chains. The intrachain correlations reveal evidences for incomplete screening of self‐interactions. However, the observed deviations are small. Our results rule out any preordering or mesophase structure formation that are proposed as precursors of polymer crystallization in the melt. Moreover, we characterize in detail primitive paths of long entangled polymer melts and we examine scaling predictions of Rouse and the reptation theory for the mean squared displacement of monomers and polymers center of mass. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2018,56, 1376–1392