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https://www.readbyqxmd.com/read/28430880/cerebral-abscess-associated-with-odontogenic-bacteremias-hypoxemia-and-iron-loading-in-immunocompetent-patients-with-right-to-left-shunting-through-pulmonary-arteriovenous-malformations
#1
E J Boother, S Brownlow, H C Tighe, K B Bamford, J E Jackson, C L Shovlin
Background: Cerebral abscess is a recognised complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Methods: Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with CT-scan confirmed PAVMs (including 403 (90.5%) with hereditary haemorrhagic telangiectasia) were recruited to a prospective series...
April 19, 2017: Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America
https://www.readbyqxmd.com/read/28430129/curcumin-inhibits-apoptosis-of-chondrocytes-through-activation-erk1-2-signaling-pathways-induced-autophagy
#2
Xiaodong Li, Kai Feng, Jiang Li, Degang Yu, Qiming Fan, Tingting Tang, Xiao Yao, Xiaoqing Wang
Osteoarthritis (OA) is an inflammatory disease of load-bearing synovial joints that is currently treated with drugs that exhibit numerous side effects and are only temporarily effective in treating pain, the main symptom of the disease. Consequently, there is an acute need for novel, safe, and more effective chemotherapeutic agents for the treatment of osteoarthritis and related arthritic diseases. Curcumin, the principal curcuminoid and the most active component in turmeric, is a biologically active phytochemical...
April 21, 2017: Nutrients
https://www.readbyqxmd.com/read/28429873/sucrose-transporters-and-plasmodesmal-regulation-in-passive-phloem-loading
#3
Johannes Liesche
An essential step for the distribution of carbon throughout the whole plant is the loading of sugars into the phloem in source organs. In many plants, accumulation of sugars in the sieve element-companion cell (SE-CC) complex is mediated and regulated by active processes. However, for poplar and many other tree species, a passive symplasmic mechanism of phloem loading has been proposed, characterized by symplasmic continuity along the pre-phloem pathway and the absence of active sugar accumulation in the SE-CC complex...
April 21, 2017: Journal of Integrative Plant Biology
https://www.readbyqxmd.com/read/28429793/attogram-mass-sensing-based-on-silicon-microbeam-resonators
#4
In-Bok Baek, Sangwon Byun, Bong Kuk Lee, Jin-Hwa Ryu, Yarkyeon Kim, Yong Sun Yoon, Won Ik Jang, Seongjae Lee, Han Young Yu
Using doubly-clamped silicon (Si) microbeam resonators, we demonstrate sub-attogram per Hertz (ag/Hz) mass sensitivity, which is extremely high sensitivity achieved by micro-scale MEMS mass sensors. We also characterize unusual buckling phenomena of the resonators. The thin-film based resonator is composed of a Si microbeam surrounded by silicon nitride (SiN) anchors, which significantly improve performance by providing fixation on the microbeam and stabilizing oscillating motion. Here, we introduce two fabrication techniques to further improve the mass sensitivity...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28429082/the-effect-of-a-combined-thoracic-and-soft-tissue-trauma-on-blood-flow-and-tissue-formation-in-fracture-healing-in-rats
#5
Lutz Claes, Florian Gebhard, Anita Ignatius, Raimund Lechner, Stefan Baumgärtel, Michael Kraus, Gert D Krischak
INTRODUCTION: Previously, it was found that fracture healing is impaired by blunt chest trauma and an additional soft-tissue trauma. The mechanisms leading to this disturbance are largely unknown. Here, we investigated the effect of thoracic and soft-tissue trauma on blood flow of the injured lower leg and on tissue differentiation and callus formation during fracture healing. MATERIALS AND METHODS: Male Wistar rats received either a mid-shaft fracture of the tibia alone (group A), an additional chest trauma (group B), or additional chest and soft-tissue traumas (group C)...
April 20, 2017: Archives of Orthopaedic and Trauma Surgery
https://www.readbyqxmd.com/read/28428544/strain-softening-of-nano-scale-fuzzy-interfaces-causes-mullins-effect-in-thermoplastic-polyurethane
#6
T Sui, E Salvati, S Ying, G Sun, I P Dolbnya, K Dragnevski, C Prisacariu, A M Korsunsky
The strain-induced softening of thermoplastic polyurethane elastomers (TPUs), known as the Mullins effect, arises from their multi-phase structure. We used the combination of small- and wide- angle X-ray scattering (SAXS/WAXS) during in situ repeated tensile loading to elucidate the relationship between molecular architecture, nano-strain, and macro-scale mechanical properties. Insights obtained from our analysis highlight the importance of the 'fuzzy interface' between the hard and soft regions that governs the structure evolution at nanometre length scales and leads to macroscopic stiffness reduction...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28428345/proliferation-of-primary-human-hepatocytes-and-prevention-of-hepatitis-b-virus-reinfection-efficiently-deplete-nuclear-cccdna-in-vivo
#7
Lena Allweiss, Tassilo Volz, Katja Giersch, Janine Kah, Giuseppina Raffa, Joerg Petersen, Ansgar W Lohse, Concetta Beninati, Teresa Pollicino, Stephan Urban, Marc Lütgehetmann, Maura Dandri
OBJECTIVE: The stability of the covalently closed circular DNA (cccDNA) in nuclei of non-dividing hepatocytes represents a key determinant of HBV persistence. Contrarily, studies with animal hepadnaviruses indicated that hepatocyte turnover can reduce cccDNA loads but knowledge on the proliferative capacity of HBV-infected primary human hepatocytes (PHHs) in vivo and the fate of cccDNA in dividing PHHs is still lacking. This study aimed to determine the impact of human hepatocyte division on cccDNA stability in vivo...
April 20, 2017: Gut
https://www.readbyqxmd.com/read/28427819/size-dependent-axial-instability-of-microtubules-surrounded-by-cytoplasm-of-a-living-cell-based-sdient-elasticity-theory
#8
S Sahmani, M M Aghdam
Microtubules including tubulin heterodimers arranging in a parallel shape of cylindrical hollow plays an important role in the mechanical stiffness of a living cell. In the present study, the nonlocal strain gradient theory of elasticity including simultaneously the both nonlocality and strain gradient size dependency is put to use within the framework of a refined orthotropic shell theory with hyperbolic distribution of shear deformation to analyze the size-dependent buckling and postbuckling characteristics of microtubules embedded in cytoplasm under axial compressive load...
April 17, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28427320/the-role-of-inelastic-deformations-in-the-mechanical-response-of-endovascular-shape-memory-alloy-devices
#9
Lorenza Petrini, Alessandro Bertini, Francesca Berti, Giancarlo Pennati, Francesco Migliavacca
Nickel-titanium alloys are commonly adopted for producing cardiovascular minimally invasive devices such as self-expandable stents, aortic valves and stent-grafts. These devices are subjected to cyclic loads (due to blood pulsatility, leg or heart movements), that can induce fatigue fracture, and may also be subjected to very large deformations (due to crimping procedure, a tortuous physiological path or overloads), that can induce material yield. Recently, the authors developed a new constitutive model that considers inelastic strains due to not-completed reverse phase transformation (not all the stress-induced martensite turns back to austenite) or/and plasticity and their accumulation during cyclic loads...
May 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28427319/mechanobiological-modelling-of-tendons-review-and-future-opportunities
#10
Mark S Thompson, M Nazri Bajuri, Hanifeh Khayyeri, Hanna Isaksson
Tendons are adapted to carry large, repeated loads and are clinically important for the maintenance of musculoskeletal health in an increasing, actively ageing population, as well as in elite athletes. Tendons are known to adapt to mechanical loading. Also, their healing and disease processes are highly sensitive to mechanical load. Computational modelling approaches developed to capture this mechanobiological adaptation in tendons and other tissues have successfully addressed many important scientific and clinical issues...
May 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28427318/load-application-for-the-contact-mechanics-analysis-and-wear-prediction-of-total-knee-replacement
#11
Jing Zhang, Zhenxian Chen, Ling Wang, Dichen Li, Zhongmin Jin
Tibiofemoral contact forces in total knee replacement have been measured at the medial and lateral sites respectively using an instrumented prosthesis, and predicted from musculoskeletal multibody dynamics models with a reasonable accuracy. However, it is uncommon that the medial and lateral forces are applied separately to replace a total axial load according to the ISO standard in the majority of current finite element analyses. In this study, we quantified the different effects of applying the medial and lateral loads separately versus the traditional total axial load application on contact mechanics and wear prediction of a patient-specific knee prosthesis...
May 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28425924/roles-of-copper-binding-proteins-in-breast-cancer
#12
REVIEW
Stéphanie Blockhuys, Pernilla Wittung-Stafshede
Copper ions are needed in several steps of cancer progression. However, the underlying mechanisms, and involved copper-binding proteins, are mainly elusive. Since most copper ions in the body (in and outside cells) are protein-bound, it is important to investigate what copper-binding proteins participate and, for these, how they are loaded with copper by copper transport proteins. Mechanistic information for how some copper-binding proteins, such as extracellular lysyl oxidase (LOX), play roles in cancer have been elucidated but there is still much to learn from a biophysical molecular viewpoint...
April 20, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28425833/management-of-missing-second-premolars-using-miniscrews-an-elective-solution-for-critical-anchorage-conditions
#13
Aldo Giancotti, Federica Paoncelli, Francesco Germano
Growing patients with congenital missing second premolars should be accurately evaluated in order to establish an appropriate treatment plan. The decision whether to close or maintain spaces in dental arches caused by missing teeth should be based on the consideration of biomechanical factors and the aesthetic traits of individual patients. Accordingly, the choice of closing spaces requires an adequate consideration of biomechanical principles in order to avoid detrimental effects on the occlusion and profile...
April 20, 2017: Journal of Orthodontics
https://www.readbyqxmd.com/read/28425588/drug-resistance-reversal-by-combretastatin-a4-phosphate-loaded-with-doxorubicin-in-polymersomes-independent-of-angiogenesis-effect
#14
Jinfang Zhu, Mengying Hu, Liyan Qiu
OBJECTIVES: This study aimed to evaluate that the polymersomes (Ps-DOX-CA4P) dual-loaded with combretastatin-A4 phosphate (CA4P) and doxorubicin (DOX) overcame drug resistance and sensitized tumour cells to chemotherapeutic drugs. METHODS: Ps-DOX-CA4P were prepared by solvent evaporation method using mPEG-b-PLA as carriers. The potential capability of CA4P to reverse DOX resistance was verified by cytotoxicity test, apoptosis assay and cellular uptake of DOX. The comparison between free drugs and drug-loaded polymersomes was also made on a single-layer cell model and multicellular tumour spheroids to display the superiority of the drug vehicles...
April 20, 2017: Journal of Pharmacy and Pharmacology
https://www.readbyqxmd.com/read/28425561/creating-homogenous-strain-distribution-within-3d-cell-encapsulated-constructs-using-a-simple-and-cost-effective-uniaxial-tensile-bioreactor-design-and-validation-study
#15
Gayathri Subramanian, Mostafa Elsaadany, Callan Bialorucki, Eda Yildirim-Ayan
Mechanical loading bioreactors capable of applying uniaxial tensile strains are emerging to be a valuable tool to investigate physiologically-relevant cellular signaling pathways and biochemical expression. In this study, we have introduced a simple and cost-effective uniaxial tensile strain bioreactor for the application of precise and homogenous uniaxial strains to 3D cell-encapsulated collagen constructs at physiological loading strains (0-12%) and frequencies (0.01-1 Hz). The bioreactor employs silicone-based loading chambers specifically designed to stretch constructs without direct gripping to minimize stress concentration at the ends of the construct and preserve its integrity...
April 20, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28425554/on-the-parallelism-between-the-mechanisms-behind-chromatography-and-drug-delivery-the-role-of-interactions-with-a-stationary-phase
#16
Filippo Rossi, Franca Castiglione, Matteo Salvalaglio, Monica Ferro, Marta Moioli, Emanuele Mauri, Maurizio Masi, Andrea Mele
A huge number of studies and work in the drug delivery literature are focused on understanding and modeling transport phenomena, the pivotal point for a good device design. The rationalization of all phenomena involved is fundamental, but several concerns arise leaving many issues unsolved. In order to change the point of view we decided to focus our attention on the parallelisms between two fields that seem to be very far from each other: chromatography and drug release. Taking advantages of the studies conducted by many researchers using chromatographic columns we decided to explain all the phenomena involved in drug delivery considering sodium ibuprofen (IP) molecules as analytes and hydrogel as a stationary phase...
April 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28424904/nanoindentation-response-of-cortical-bone-dependency-of-subsurface-voids
#17
Masoud Ramezanzadehkoldeh, Bjørn Skallerud
Nanoindentation test results in the axial direction of mouse femurs were the basis for the current study. Although the majority of the nanoindentation curves showed a reasonable consistency, some curves showed a significantly softer response. Detailed investigation, using focused ion beam-scanning electron microscopy, provided that the softer response is due to subsurface cavities such as lacunae. Finite element models were developed to simulate the nanoindentation of mice femur cortical bone samples with and without the incorporation of a single lacuna underneath the bone surface...
April 19, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28424791/antifatigue-effects-of-antrodia-cinnamomea-cultured-mycelium-via-modulation-of-oxidative-stress-signaling-in-a-mouse-model
#18
Yange Liu, Lanzhou Li, Shengshu An, Yuanzhu Zhang, Shiwei Feng, Lu Zhao, Lirong Teng, Di Wang
Antrodia cinnamomea, a folk medicinal mushroom, has numerous biological effects. In this study, we aim to assess whether the antifatigue effects of A. cinnamomea mycelia (AC) and its underlying mechanisms are related to oxidative stress signaling using behavioral mouse models and biochemical indices detection. Mice were orally treated with AC at doses of 0.1, 0.3, and 0.9 g/kg for three weeks. AC had no effect on the spontaneous activities of mice indicating its safety on central nervous system. Furthermore, results obtained from weight-loaded forced swimming test, rotary rod test, and exhausted running test confirmed that AC significantly enhanced exercise tolerance of mice...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28424688/antimicrobial-activity-of-mesenchymal-stem-cells-current-status-and-new-perspectives-of-antimicrobial-peptide-based-therapies
#19
REVIEW
Francisca Alcayaga-Miranda, Jimena Cuenca, Maroun Khoury
While mesenchymal stem cells (MSCs)-based therapy appears to be promising, there are concerns regarding possible side effects related to the unwanted suppression of antimicrobial immunity leading to an increased risk of infection. Conversely, recent data show that MSCs exert strong antimicrobial effects through indirect and direct mechanisms, partially mediated by the secretion of antimicrobial peptides and proteins (AMPs). In fact, MSCs have been reported to increase bacterial clearance in preclinical models of sepsis, acute respiratory distress syndrome, and cystic fibrosis-related infections...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/28424631/mechanisms-underlying-the-emergence-of-post-acidosis-arrhythmia-at-the-tissue-level-a-theoretical-study
#20
Jieyun Bai, Renli Yin, Kuanquan Wang, Henggui Zhang
Acidosis has complex electrophysiological effects, which are associated with a high recurrence of ventricular arrhythmias. Through multi-scale cardiac computer modeling, this study investigated the mechanisms underlying the emergence of post-acidosis arrhythmia at the tissue level. In simulations, ten Tusscher-Panfilov ventricular model was modified to incorporate various data on acidosis-induced alterations of cellular electrophysiology and intercellular electrical coupling. The single cell models were incorporated into multicellular one-dimensional (1D) fiber and 2D sheet tissue models...
2017: Frontiers in Physiology
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