BioMed Research International: Biophysics http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Accuracy and Repeatability of the Gait Analysis by the WalkinSense System Thu, 20 Feb 2014 09:43:13 +0000 http://www.hindawi.com/journals/bmri/2014/348659/ WalkinSense is a new device designed to monitor walking. The aim of this study was to measure the accuracy and repeatability of the gait analysis performed by the WalkinSense system. Descriptions of values recorded by WalkinSense depicting typical gait in adults are also presented. A bench experiment using the Trublu calibration device was conducted to statically test the WalkinSense. Following this, a dynamic test was carried out overlapping the WalkinSense and the Pedar insoles in 40 healthy participants during walking. Pressure peak, pressure peak time, pressure-time integral, and mean pressure at eight-foot regions were calculated. In the bench experiments, the repeatability (i) among the WalkinSense sensors (within), (ii) between two WalkinSense devices, and (iii) between the WalkinSense and the Trublu devices was excellent. In the dynamic tests, the repeatability of the WalkinSense (i) between stances in the same trial (within-trial) and (ii) between trials was also excellent (ICC > 0.90). When the eight-foot regions were analyzed separately, the within-trial and between-trials repeatability was good-to-excellent in 88% (ICC > 0.80) of the data and fair in 11%. In short, the data suggest that the WalkinSense has good-to-excellent levels of accuracy and repeatability for plantar pressure variables. Marcelo P. de Castro, Marco Meucci, Denise P. Soares, Pedro Fonseca, Márcio Borgonovo-Santos, Filipa Sousa, Leandro Machado, and João Paulo Vilas-Boas Copyright © 2014 Marcelo P. de Castro et al. All rights reserved. Development of a Stair-Step Multifrequency Synchronized Excitation Signal for Fast Bioimpedance Spectroscopy Wed, 19 Feb 2014 09:58:46 +0000 http://www.hindawi.com/journals/bmri/2014/143461/ Wideband excitation signal with finite prominent harmonic components is desirable for fast bioimpedance spectroscopy (BIS) measurements. This work introduces a simple method to synthesize and realize a type of periodical stair-step multifrequency synchronized (MFS) signal. The Fourier series analysis shows that the p-order MFS signal has constant 81.06% energy distributed equally on its p  th primary harmonics. The synthesis principle is described firstly and then two examples of the 4-order and 5-order MFS signals, and , are synthesized. The method to implement the MFS waveform based on a field-programmable gate array (FPGA) and a digital to analog converter (DAC) is also presented. Both the number and the frequencies of the expected primary harmonics can be adjusted as needed. An impedance measurement experiment on a RC three-element equivalent model is performed, and results show acceptable precision, which validates the feasibility of the MFS excitation. Yuxiang Yang, He Bian, Fangling Du, Qiang Sun, and He Wen Copyright © 2014 Yuxiang Yang et al. All rights reserved. Energy Absorption and Exposure Buildup Factors of Essential Amino Acids Wed, 29 Jan 2014 13:21:13 +0000 http://www.hindawi.com/journals/bmri/2014/359754/ The effective atomic number and effective electron density in amino acids are of significant interest due to their use in various applications. The energy absorption buildup factors, exposure buildup factors, effective atomic numbers, and electron densities of essential amino acids such as Leucine (C6H13NO2), Lysine (C6H14N2O2), Methionine (C5H11NO2S), Phenylalanine (C9H11NO2), Threonine (C4H9NO3), Tryptophan (C11H12N2O2), Valine (C5H11NO2), Arginine (C6H14N4O2), and Histidine (C6H9N3O2) were determined theoretically in the energy range 0.015–15 MeV. Ertuğrul Bursalıoğlu, Begüm Balkan, H. Birtan Kavanoz, Mustafa Okutan, Orhan İçelli, and Zeynel Yalçın Copyright © 2014 Ertuğrul Bursalıoğlu et al. All rights reserved. Different Effects of the Immunomodulatory Drug GMDP Immobilized onto Aminopropyl Modified and Unmodified Mesoporous Silica Nanoparticles upon Peritoneal Macrophages of Women with Endometriosis Tue, 24 Dec 2013 16:58:53 +0000 http://www.hindawi.com/journals/bmri/2013/924362/ The aim of the present work was to compare in vitro the possibility of application of unmodified silica nanoparticles (UMNPs) and modified by aminopropyl groups silica nanoparticles (AMNPs) for topical delivery of immunomodulatory drug GMDP to the peritoneal macrophages of women with endometriosis. The absence of cytotoxic effect and high cellular uptake was demonstrated for both types of silica nanoparticles. The immobilization of GMDP on the UMNPs led to the suppression of the stimulatory effect of GMDP on the membrane expression of scavenger receptors SR-AI and SR-B, mRNAs expression of NOD2 and RAGE, and synthesis of proteolytic enzyme MMP-9 and its inhibitor TIMP-1. GMDP, immobilized onto AMNPs, enhanced the initially reduced membrane expression of SRs and increased NOD2, RAGE, and MMP-9 mRNAs expression by macrophages. Simultaneously high level of mRNAs expression of factors, preventing undesirable hyperactivation of peritoneal macrophages (SOCS1 and TIMP-1), was observed in macrophages incubated in the presence of GMDP, immobilized onto AMNPs. The effect of AMNPs immobilized GMDP in some cases exceeded the effect of free GMDP. Thus, among the studied types of silica nanoparticles, AMNPs are the most suitable nanoparticles for topical delivery of GMDP to the peritoneal macrophages. Yuliya Antsiferova, Nataliya Sotnikova, and Elena Parfenyuk Copyright © 2013 Yuliya Antsiferova et al. All rights reserved. External Mechanical Microstimuli Modulate the Osseointegration of Titanium Implants in Rat Tibiae Tue, 03 Dec 2013 14:42:13 +0000 http://www.hindawi.com/journals/bmri/2013/234093/ Purpose. To assess the effect of external mechanical microstimuli of controlled magnitude on the microarchitecture of the peri-implant bone beds in rat tibiae. Materials and Methods. Tibiae of forty rats were fitted with two transcutaneous titanium cylinders. After healing, the implants were loaded to 1 to 3 N, five days/week for four weeks. These force levels translated into intraosseous strains of , , and . After sacrifice, the implants’ pullout strength was assessed. Second, the bone’s microarchitecture was analyzed by microcomputed tomography (CT) in three discrete regions of interest (ROIs). Third, the effect of loading on bone material properties was determined by nanoindentation. Results. The trabecular BV/TV significantly increased in an ROI of 0.98 mm away from the test implant in the 1 N versus the 3 N group with an opposite trend for cortical thickness. Pull-out strength significantly increased in the 2 N relatively to the nonstimulated group. Higher values of E-modulus and hardness were observed in the trabecular bone of the 2 N group. Conclusion. The in vivo mechanical loading of implants induces load-dependent modifications in bone microarchitecture and bone material properties in rat tibiae. In pull-out strength measurements, implant osseointegration was maximized at 2 N . Giovanna Zacchetti, Anselm Wiskott, Joël Cugnoni, John Botsis, and Patrick Ammann Copyright © 2013 Giovanna Zacchetti et al. All rights reserved. Magnetic Retraction of Bowel by Intraluminal Injectable Cyanoacrylate-Based Magnetic Glue Tue, 12 Nov 2013 14:34:48 +0000 http://www.hindawi.com/journals/bmri/2013/526512/ Magnetic retraction offers advantages over physical retraction by graspers because of reduced tissue trauma. The objectives of this study are to investigate a novel method of magnetisation of bowel segments by intraluminal injection of magnetic glue and to demonstrate the feasibility of magnetic retraction of bowel with sufficient force during minimal access surgery. Following an initial materials characterisation study, selected microparticles of stainless steel (SS410-μPs) were mixed with chosen cyanoacrylate glue (Loctite 4014). During intraluminal injection of the magnetic glue using ex vivo porcine colonic segments, a magnetic probe placed at the injected site ensured that the SS410-μPs aggregated during glue polymerisation to form an intraluminal mucosally adherent coagulum. The magnetised colonic segments were retracted by magnetic probes (5 and 10 mm) placed external to the bowel wall. A tensiometer was used to record the retraction force. With an injected volume of 2 mL in a particle concentration of 1 g/mL, this technique produced maximal magnetic retraction forces of 2.24 ± 0.23 N and 5.11 ± 0.34 N (), with use of 5 and 10 mm probes, respectively. The results indicate that the formation of an intraluminal coagulum based on SS410-μPs and Loctite 4014 produces sufficient magnetic retraction for bowel retraction. Zhigang Wang, Andrew Brown, Pascal André, Stuart I. Brown, Gordon J. Florence, and Alfred Cuschieri Copyright © 2013 Zhigang Wang et al. All rights reserved. Sensitivity of Rabbit Ventricular Action Potential and Ca2+ Dynamics to Small Variations in Membrane Currents and Ion Diffusion Coefficients Mon, 07 Oct 2013 11:29:20 +0000 http://www.hindawi.com/journals/bmri/2013/565431/ Little is known about how small variations in ionic currents and and diffusion coefficients impact action potential and dynamics in rabbit ventricular myocytes. We applied sensitivity analysis to quantify the sensitivity of Shannon et al. model (Biophys. J., 2004) to 5%–10% changes in currents conductance, channels distribution, and ion diffusion in rabbit ventricular cells. We found that action potential duration and peaks are highly sensitive to 10% increase in L-type current; moderately influenced by 10% increase in - exchanger, - pump, rapid delayed and slow transient outward currents, and background current; insensitive to 10% increases in all other ionic currents and sarcoplasmic reticulum fluxes. Cell electrical activity is strongly affected by 5% shift of L-type channels and - exchanger in between junctional and submembrane spaces while -activated -channel redistribution has the modest effect. Small changes in submembrane and cytosolic diffusion coefficients for , but not in transfer, may alter notably myocyte contraction. Our studies highlight the need for more precise measurements and further extending and testing of the Shannon et al. model. Our results demonstrate usefulness of sensitivity analysis to identify specific knowledge gaps and controversies related to ventricular cell electrophysiology and signaling. Yuan Hung Lo, Tom Peachey, David Abramson, Andrew McCulloch, and Anushka Michailova Copyright © 2013 Yuan Hung Lo et al. All rights reserved. A Numerical Study to Compare Stimulations by Intraoperative Microelectrodes and Chronic Macroelectrodes in the DBS Technique Mon, 07 Oct 2013 08:21:16 +0000 http://www.hindawi.com/journals/bmri/2013/262739/ Deep brain stimulation is a clinical technique for the treatment of parkinson's disease based on the electric stimulation, through an implanted electrode, of specific basal ganglia in the brain. To identify the correct target of stimulation and to choose the optimal parameters for the stimulating signal, intraoperative microelectrodes are generally used. However, when they are replaced with the chronic macroelectrode, the effect of the stimulation is often very different. Here, we used numerical simulations to predict the stimulation of neuronal fibers induced by microelectrodes and macroelectrodes placed in different positions with respect to each other. Results indicate that comparable stimulations can be obtained if the chronic macroelectrode is correctly positioned with the same electric center of the intraoperative microelectrode. Otherwise, some groups of fibers may experience a completely different electric stimulation. A. Paffi, F. Apollonio, M. G. Puxeddu, M. Parazzini, G. d'Inzeo, P. Ravazzani, and M. Liberti Copyright © 2013 A. Paffi et al. All rights reserved. Ultraviolet-Visible and Fluorescence Spectroscopy Techniques Are Important Diagnostic Tools during the Progression of Atherosclerosis: Diet Zinc Supplementation Retarded or Delayed Atherosclerosis Tue, 01 Oct 2013 11:16:13 +0000 http://www.hindawi.com/journals/bmri/2013/652604/ Background. In this study, we examined whether UV-visible and fluorescence spectroscopy techniques detect the progression of atherosclerosis in serum of rabbits fed on high-cholesterol diet (HCD) and HCD supplemented with zinc (HCD + Zn) compared with the control. Methods. The control rabbits group was fed on 100 g/day of normal diet. The HCD group was fed on Purina Certified Rabbit Chow supplemented with 1.0% cholesterol plus 1.0% olive oil (100 g/day) for the same period. The HCD + Zn group was fed on normal Purina Certified Rabbit Chow plus 1.0% cholesterol and 1.0% olive oil supplemented with 470 ppm Zn for the same feeding period. UV-visible and fluorescence spectroscopy and biochemistry in Rabbit’s blood serum and blood hematology were measured in Rabbit’s blood. Results. We found that the fluorescent peak of HCD shifted toward UV-visible wavelength compared with the control using fluorescent excitation of serum at 192 nm. In addition, they showed that supplementation of zinc (350 ppm) restored the fluorescent peak closely to the control. By using UV-visible spectroscopy approach, we found that the peak absorbance of HCD (about 280 nm) was higher than that of control and that zinc supplementation seemed to decrease the absorbance. Conclusions. This study demonstrates that ultraviolet-visible and fluorescence spectroscopy techniques can be applied as noninvasive techniques on a sample blood serum for diagnosing or detecting the progression of atherosclerosis. The Zn supplementation to rabbits fed on HCD delays or retards the progression of atherosclerosis. Inducing anemia in rabbits fed on HCD delays the progression of atherosclerosis. Mohamed Anwar K. Abdelhalim, Sherif A. Abdelmottaleb Moussa, and Yanallah Hussain AL-Mohy Copyright © 2013 Mohamed Anwar K. Abdelhalim et al. All rights reserved. Biomechanics Mon, 02 Sep 2013 14:08:33 +0000 http://www.hindawi.com/journals/bmri/2013/271543/ José M. Vilar, Francisco Miró, Miguel A. Rivero, and Giuseppe Spinella Copyright © 2013 José M. Vilar et al. All rights reserved. The Measurement of Maximal (Anaerobic) Power Output on a Cycle Ergometer: A Critical Review Thu, 29 Aug 2013 14:00:12 +0000 http://www.hindawi.com/journals/bmri/2013/589361/ The interests and limits of the different methods and protocols of maximal (anaerobic) power () assessment are reviewed: single all-out tests versus force-velocity tests, isokinetic ergometers versus friction-loaded ergometers, measure of during the acceleration phase or at peak velocity. The effects of training, athletic practice, diet and pharmacological substances upon the production of maximal mechanical power are not discussed in this review mainly focused on the technical (ergometer, crank length, toe clips), methodological (protocols) and biological factors (muscle volume, muscle fiber type, age, gender, growth, temperature, chronobiology and fatigue) limiting in cycling. Although the validity of the Wingate test is questionable, a large part of the review is dedicated to this test which is currently the all-out cycling test the most often used. The biomechanical characteristics specific of maximal and high speed cycling, the bioenergetics of the all-out cycling exercises and the influence of biochemical factors (acidosis and alkalosis, phosphate ions…) are recalled at the beginning of the paper. The basic knowledge concerning the consequences of the force-velocity relationship upon power output, the biomechanics of sub-maximal cycling exercises and the study on the force-velocity relationship in cycling by Dickinson in 1928 are presented in Appendices. Tarak Driss and Henry Vandewalle Copyright © 2013 Tarak Driss and Henry Vandewalle. All rights reserved. Radiation-Induced Noncancer Risks in Interventional Cardiology: Optimisation of Procedures and Staff and Patient Dose Reduction Tue, 20 Aug 2013 14:26:29 +0000 http://www.hindawi.com/journals/bmri/2013/976962/ Concerns about ionizing radiation during interventional cardiology have been increased in recent years as a result of rapid growth in interventional procedure volumes and the high radiation doses associated with some procedures. Noncancer radiation risks to cardiologists and medical staff in terms of radiation-induced cataracts and skin injuries for patients appear clear potential consequences of interventional cardiology procedures, while radiation-induced potential risk of developing cardiovascular effects remains less clear. This paper provides an overview of the evidence-based reviews of concerns about noncancer risks of radiation exposure in interventional cardiology. Strategies commonly undertaken to reduce radiation doses to both medical staff and patients during interventional cardiology procedures are discussed; optimisation of interventional cardiology procedures is highlighted. Zhonghua Sun, Aini AbAziz, and Ahmad Khairuddin Md Yusof Copyright © 2013 Zhonghua Sun et al. All rights reserved. Bioeffects of Static Magnetic Fields: Oxidative Stress, Genotoxic Effects, and Cancer Studies Tue, 06 Aug 2013 08:36:42 +0000 http://www.hindawi.com/journals/bmri/2013/602987/ The interaction of static magnetic fields (SMFs) with living organisms is a rapidly growing field of investigation. The magnetic fields (MFs) effect observed with radical pair recombination is one of the well-known mechanisms by which MFs interact with biological systems. Exposure to SMF can increase the activity, concentration, and life time of paramagnetic free radicals, which might cause oxidative stress, genetic mutation, and/or apoptosis. Current evidence suggests that cell proliferation can be influenced by a treatment with both SMFs and anticancer drugs. It has been recently found that SMFs can enhance the anticancer effect of chemotherapeutic drugs; this may provide a new strategy for cancer therapy. This review focuses on our own data and other data from the literature of SMFs bioeffects. Three main areas of investigation have been covered: free radical generation and oxidative stress, apoptosis and genotoxicity, and cancer. After an introduction on SMF classification and medical applications, the basic phenomena to understand the bioeffects are described. The scientific literature is summarized, integrated, and critically analyzed with the help of authoritative reviews by recognized experts; international safety guidelines are also cited. Soumaya Ghodbane, Aida Lahbib, Mohsen Sakly, and Hafedh Abdelmelek Copyright © 2013 Soumaya Ghodbane et al. All rights reserved. Ascorbic Acid and BSA Protein in Solution and Films: Interaction and Surface Morphological Structure Thu, 25 Jul 2013 14:18:56 +0000 http://www.hindawi.com/journals/bmri/2013/461365/ This paper reports on the study of the interactions between ascorbic acid (AA) and bovine serum albumin (BSA) in aqueous solution as well as in films (BSA/AA films) prepared by the layer-by-layer technique. Regarding to solution studies, a hyperchromism (in the range of ultraviolet) was found as a function of AA concentration, which suggested the formation of aggregates from AA and BSA. Binding constant, , determined for aggregates from BSA and AA was found to be about 102 M−1, which indicated low affinity of AA with BSA. For the BSA/AA films, it was also noted that the AA adsorption process and surface morphological structures depended on AA concentration. By changing the contact time between the AA and BSA, a hypochromism was revealed, which was associated to decrease of accessibility of solvent to tryptophan due to formation of aggregates. Furthermore, different morphological structures of aggregates were observed, which were attributed to the diffusion-limited aggregation. Since most of studies of interactions of drugs and proteins are performed in solution, the analysis of these processes by using films can be very valuable because this kind of system is able to employ several techniques of investigation in solid state. Rafael R. G. Maciel, Adriele A. de Almeida, Odin G. C. Godinho, Filipe D. S. Gorza, Graciela C. Pedro, Tarquin F. Trescher, Josmary R. Silva, and Nara C. de Souza Copyright © 2013 Rafael R. G. Maciel et al. All rights reserved. Computational Fluid Dynamics Study of Swimmer's Hand Velocity, Orientation, and Shape: Contributions to Hydrodynamics Tue, 09 Apr 2013 14:28:02 +0000 http://www.hindawi.com/journals/bmri/2013/140487/ The aim of this paper is to determine the hydrodynamic characteristics of swimmer’s scanned hand models for various combinations of both the angle of attack and the sweepback angle and shape and velocity of swimmer's hand, simulating separate underwater arm stroke phases of freestyle (front crawl) swimming. Four realistic 3D models of swimmer's hand corresponding to different combinations of separated/closed fingers positions were used to simulate different underwater front crawl phases. The fluid flow was simulated using FLUENT (ANSYS, PA, USA). Drag force and drag coefficient were calculated using (computational fluid dynamics) CFD in steady state. Results showed that the drag force and coefficient varied at the different flow velocities on all shapes of the hand and variation was observed for different hand positions corresponding to different stroke phases. The models of the hand with thumb adducted and abducted generated the highest drag forces and drag coefficients. The current study suggests that the realistic variation of both the orientation angles influenced higher values of drag, lift, and resultant coefficients and forces. To augment resultant force, which affects swimmer's propulsion, the swimmer should concentrate in effectively optimising achievable hand areas during crucial propulsive phases. Milda Bilinauskaite, Vishveshwar Rajendra Mantha, Abel Ilah Rouboa, Pranas Ziliukas, and Antonio Jose Silva Copyright © 2013 Milda Bilinauskaite et al. All rights reserved. Interplay of Biomechanical, Energetic, Coordinative, and Muscular Factors in a 200 m Front Crawl Swim Sun, 17 Mar 2013 14:20:40 +0000 http://www.hindawi.com/journals/bmri/2013/897232/ This study aimed to determine the relative contribution of selected biomechanical, energetic, coordinative, and muscular factors for the 200 m front crawl and each of its four laps. Ten swimmers performed a 200 m front crawl swim, as well as 50, 100, and 150 m at the 200 m pace. Biomechanical, energetic, coordinative, and muscular factors were assessed during the 200 m swim. Multiple linear regression analysis was used to identify the weight of the factors to the performance. For each lap, the contributions to the 200 m performance were 17.6, 21.1, 18.4, and 7.6% for stroke length, 16.1, 18.7, 32.1, and 3.2% for stroke rate, 11.2, 13.2, 6.8, and 5.7% for intracycle velocity variation in x, 9.7, 7.5, 1.3, and 5.4% for intracycle velocity variation in y, 17.8, 10.5, 2.0, and 6.4% for propelling efficiency, 4.5, 5.8, 10.9, and 23.7% for total energy expenditure, 10.1, 5.1, 8.3, and 23.7% for interarm coordination, 9.0, 6.2, 8.5, and 5.5% for muscular activity amplitude, and 3.9, 11.9, 11.8, and 18.7% for muscular frequency). The relative contribution of the factors was closely related to the task constraints, especially fatigue, as the major changes occurred from the first to the last lap. Pedro Figueiredo, David R. Pendergast, João Paulo Vilas-Boas, and Ricardo J. Fernandes Copyright © 2013 Pedro Figueiredo et al. All rights reserved. Kinematic Measures during a Clinical Diagnostic Technique for Human Neck Disorder: Inter- and Intraexaminer Comparisons Sat, 16 Feb 2013 15:00:26 +0000 http://www.hindawi.com/journals/bmri/2013/950719/ Diagnoses of human musculoskeletal dysfunction of the cervical spine are indicated by palpable clues of a patient’s structural compliance/noncompliance as this body segment responds to diagnostic motion demands applied by a clinician. This process includes assessments of motion range, motion performance, and changes in tissue responses. However, biomechanical quantification of these diagnostic actions and their reproducible components is lacking. As a result, this study sought to use objective kinematic measures to capture aspects of the diagnostic process to compare inter- and intraexaminer motion behaviors when performing a specific clinical diagnostic protocol. Pain-free volunteers and a group determined to be symptomatic based on a psychometric pain score were examined by two clinicians while three-dimensional kinematic data were collected. Intraexaminer diagnostic motion ranges of cervical lateral flexion and secondary rotations were consistent for each examiner and for each subject group. However, interexaminer comparisons for motion range, secondary rotations, and average velocities yielded consistently larger measures for one examiner for both subject groups (). This research demonstrates that fundamental aspects of the clinical diagnostic process for human neck disorders can be identified and measured using kinematic parameters. Further, these objective data have the potential to be linked to clinical decision making. Joseph Vorro, Tamara R. Bush, Brad Rutledge, and Mingfei Li Copyright © 2013 Joseph Vorro et al. All rights reserved. Relationship between Anthropometric Factors, Gender, and Balance under Unstable Conditions in Young Adults Wed, 16 Jan 2013 17:49:25 +0000 http://www.hindawi.com/journals/bmri/2013/850424/ The objective of this study was to evaluate the relationship between the anthropometric factors of height, body mass, body mass index and postural balance and to compare the balance indices between genders in the upright standing position, in healthy adult subjects under conditions of instability. Forty individuals were subjected to functional tests of body stability using the Biodex Balance System, and the resulting indices were correlated with body mass, height, and body mass index, and also compared between genders. Body mass was the main anthropometric factor that influenced variations in postural balance, with a high correlation between groups and with all variables. A linear regression analysis showed that body mass associated with BMI explained 66% of the overall stability, and body mass explained 59% of the anteroposterior stability index and 65% of the mediolateral stability index. In the female group, body mass explained 72% of the overall balance, 66% of the anteroposterior, and 76% of the medio-lateral stability index. Increased body mass requires greater movements to maintain postural balance. Height and BMI presented moderate correlations with balance. Women showed less movement than men on the Biodex Balance System. Júlia Maria D’Andréa Greve, Mutlu Cuğ, Deniz Dülgeroğlu, Guilherme Carlos Brech, and Angelica Castilho Alonso Copyright © 2013 Júlia Maria D’Andréa Greve et al. All rights reserved. Extremely Low-Frequency Magnetic Field Enhances the Therapeutic Efficacy of Low-Dose Cisplatin in the Treatment of Ehrlich Carcinoma Mon, 14 Jan 2013 10:55:40 +0000 http://www.hindawi.com/journals/bmri/2013/189352/ The present study examines the therapeutic efficacy of the administration of low-dose cisplatin (cis) followed by exposure to extremely low-frequency magnetic field (ELF-MF), with an average intensity of 10 mT, on Ehrlich carcinoma in vivo. The cytotoxic and genotoxic actions of this combination were studied using comet assay, mitotic index (MI), and the induction of micronucleus (MN). Moreover, the inhibition of tumor growth was also measured. Treatment with cisplatin and ELF-MF (group A) increased the number of damaged cells by 54% compared with 41% for mice treated with cisplatin alone (group B), 20% for mice treated by exposure to ELF-MF (group C), and 9% for the control group (group D). Also the mitotic index decreased significantly for all treated groups (). The decrement percent for the treated groups (A, B, and C) were 70%, 65%, and 22%, respectively, compared with the control group (D). Additionally, the rate of tumor growth at day 12 was suppressed significantly () for groups A, B, and C with respect to group (D). These results suggest that ELF-MF enhanced the cytotoxic activity of cisplatin and potentiate the benefit of using a combination of low-dose cisplatin and ELF-MF in the treatment of Ehrlich carcinoma. Nihal S. El-Bialy and Monira M. Rageh Copyright © 2013 Nihal S. El-Bialy and Monira M. Rageh. All rights reserved. Repeated Bout Effect Was More Expressed in Young Adult Males Than in Elderly Males and Boys Tue, 01 Jan 2013 08:19:22 +0000 http://www.hindawi.com/journals/bmri/2013/218970/ This study investigated possible differences using the same stretch-shortening exercise (SSE) protocol on generally accepted monitoring markers (dependent variables: changes in creatine kinase, muscle soreness, and voluntary and electrically evoked torque) in males across three lifespan stages (childhood versus adulthood versus old age). The protocol consisted of 100 intermittent (30 s interval between jumps) drop jumps to determine the repeated bout effect (RBE) (first and second bouts performed at a 2-week interval). The results showed that indirect symptoms of exercise-induced muscle damage after SSE were more expressed in adult males than in boys and elderly males, suggesting that the muscles of boys and elderly males are more resistant to exercise-induced damage than those of adult males. RBE was more pronounced in adult males than in boys and elderly males, suggesting that the muscles of boys and elderly males are less adaptive to exercise-induced muscle damage than those of adult males. Giedrius Gorianovas, Albertas Skurvydas, Vytautas Streckis, Marius Brazaitis, Sigitas Kamandulis, and Malachy P. McHugh Copyright © 2013 Giedrius Gorianovas et al. All rights reserved. Determination of Poisson Ratio of Bovine Extraocular Muscle by Computed X-Ray Tomography Sun, 30 Dec 2012 16:55:09 +0000 http://www.hindawi.com/journals/bmri/2013/197479/ The Poisson ratio (PR) is a fundamental mechanical parameter that approximates the ratio of relative change in cross sectional area to tensile elongation. However, the PR of extraocular muscle (EOM) is almost never measured because of experimental constraints. The problem was overcome by determining changes in EOM dimensions using computed X-ray tomography (CT) at microscopic resolution during tensile elongation to determine transverse strain indicated by the change in cross-section. Fresh bovine EOM specimens were prepared. Specimens were clamped in a tensile fixture within a CT scanner (SkyScan, Belgium) with temperature and humidity control and stretched up to 35% of initial length. Sets of 500–800 contiguous CT images were obtained at 10-micron resolution before and after tensile loading. Digital 3D models were then built and discretized into 6–8-micron-thick elements. Changes in longitudinal thickness of each microscopic element were determined to calculate strain. Green’s theorem was used to calculate areal strain in transverse directions orthogonal to the stretching direction. The mean PR from discretized 3D models for every microscopic element in 14 EOM specimens averaged (SD). The measured PR of bovine EOM is thus near the limit of incompressibility. Hansang Kim, Lawrence Yoo, Andrew Shin, and Joseph L. Demer Copyright © 2013 Hansang Kim et al. All rights reserved. Cell Mechanosensitivity: Mechanical Properties and Interaction with Gravitational Field Wed, 26 Dec 2012 17:25:32 +0000 http://www.hindawi.com/journals/bmri/2013/598461/ This paper addressed the possible mechanisms of primary reception of a mechanical stimulus by different cells. Data concerning the stiffness of muscle and nonmuscle cells as measured by atomic force microscopy are provided. The changes in the mechanical properties of cells that occur under changed external mechanical tension are presented, and the initial stages of mechanical signal transduction are considered. The possible mechanism of perception of different external mechanical signals by cells is suggested. I. V. Ogneva Copyright © 2013 I. V. Ogneva. All rights reserved. Corticospinal Reorganization after Locomotor Training in a Person with Motor Incomplete Paraplegia Wed, 26 Dec 2012 09:08:09 +0000 http://www.hindawi.com/journals/bmri/2013/516427/ Activity-dependent plasticity as a result of reorganization of neural circuits is a fundamental characteristic of the central nervous system that occurs simultaneously in multiple sites. In this study, we established the effects of subthreshold transcranial magnetic stimulation (TMS) over the primary motor cortex region on the tibialis anterior (TA) long-latency flexion reflex. Neurophysiological tests were conducted before and after robotic gait training in one person with a motor incomplete spinal cord injury (SCI) while at rest and during robotic-assisted stepping. The TA flexion reflex was evoked following nonnociceptive sural nerve stimulation and was conditioned by TMS at 0.9 TA motor evoked potential resting threshold at conditioning-test intervals that ranged from 70 to 130 ms. Subthreshold TMS induced a significant facilitation on the TA flexion reflex before training, which was reversed to depression after training with the subject seated at rest. During stepping, corticospinal facilitation of the flexion reflex at early and midstance phases before training was replaced with depression at early and midswing followed by facilitation at late swing after training. These results constitute the first neurophysiologic evidence that locomotor training reorganizes the cortical control of spinal interneuronal circuits that generate patterned motor activity, modifying spinal reflex function, in the chronic lesioned human spinal cord. Nupur Hajela, Chaithanya K. Mummidisetty, Andrew C. Smith, and Maria Knikou Copyright © 2013 Nupur Hajela et al. All rights reserved. In Vivo Healthy Knee Kinematics during Dynamic Full Flexion Sun, 23 Dec 2012 11:46:00 +0000 http://www.hindawi.com/journals/bmri/2013/717546/ Healthy knee kinematics during dynamic full flexion were evaluated using 3D-to-2D model registration techniques. Continuous knee motions were recorded during full flexion in a lunge from 85° to 150°. Medial and lateral tibiofemoral contacts and femoral internal-external and varus-valgus rotations were analyzed as a function of knee flexion angle. The medial tibiofemoral contact translated anteroposteriorly, but remained on the center of the medial compartment. On the other hand, the lateral tibiofemoral contact translated posteriorly to the edge of the tibial surface at 150° flexion. The femur exhibited external and valgus rotation relative to the tibia over the entire activity and reached 30° external and 5° valgus rotations at 150° flexion. Kinematics’ data during dynamic full flexion may provide important insight as to the designing of high-flexion total knee prostheses. Satoshi Hamai, Taka-aki Moro-oka, Nicholas J. Dunbar, Hiromasa Miura, Yukihide Iwamoto, and Scott A. Banks Copyright © 2013 Satoshi Hamai et al. All rights reserved. Lower-Limb Joint Coordination Pattern in Obese Subjects Wed, 19 Dec 2012 13:50:09 +0000 http://www.hindawi.com/journals/bmri/2013/142323/ The coordinative pattern is an important feature of locomotion that has been studied in a number of pathologies. It has been observed that adaptive changes in coordination patterns are due to both external and internal constraints. Obesity is characterized by the presence of excess mass at pelvis and lower-limb areas, causing mechanical constraints that central nervous system could manage modifying the physiological interjoint coupling relationships. Since an altered coordination pattern may induce joint diseases and falls risk, the aim of this study was to analyze whether and how coordination during walking is affected by obesity. We evaluated interjoint coordination during walking in 25 obese subjects as well as in a control group. The time-distance parameters and joint kinematics were also measured. When compared with the control group, obese people displayed a substantial similarity in joint kinematic parameters and some differences in the time-distance and in the coupling parameters. Obese subjects revealed higher values in stride-to-stride intrasubjects variability in interjoint coupling parameters, whereas the coordinative mean pattern was unaltered. The increased variability in the coupling parameters is associated with an increased risk of falls and thus should be taken into account when designing treatments aimed at restoring a normal locomotion pattern. Alberto Ranavolo, Lorenzo M. Donini, Silvia Mari, Mariano Serrao, Alessio Silvetti, Sergio Iavicoli, Edda Cava, Rosa Asprino, Alessandro Pinto, and Francesco Draicchio Copyright © 2013 Alberto Ranavolo et al. All rights reserved. Development and Kinematic Verification of a Finite Element Model for the Lumbar Spine: Application to Disc Degeneration Wed, 05 Dec 2012 07:35:39 +0000 http://www.hindawi.com/journals/bmri/2013/705185/ The knowledge of the lumbar spine biomechanics is essential for clinical applications. Due to the difficulties to experiment on living people and the irregular results published, simulation based on finite elements (FE) has been developed, making it possible to adequately reproduce the biomechanics of the lumbar spine. A 3D FE model of the complete lumbar spine (vertebrae, discs, and ligaments) has been developed. To verify the model, radiological images (X-rays) were taken over a group of 25 healthy, male individuals with average age of 27.4 and average weight of 78.6 kg with the corresponding informed consent. A maximum angle of 34.40° is achieved in flexion and of 35.58° in extension with a flexion-extension angle of 69.98°. The radiological measurements were 33.94 ± 4.91°, 38.73 ± 4.29°, and 72.67°, respectively. In lateral bending, the maximum angles were 19.33° and 23.40 ± 2.39, respectively. In rotation a maximum angle of 9.96° was obtained. The model incorporates a precise geometrical characterization of several elements (vertebrae, discs, and ligaments), respecting anatomical features and being capable of reproducing a wide range of physiological movements. Application to disc degeneration (L5-S1) allows predicting the affection in the mobility of the different lumbar segments, by means of parametric studies for different ranges of degeneration. Elena Ibarz, Antonio Herrera, Yolanda Más, Javier Rodríguez-Vela, José Cegoñino, Sergio Puértolas, and Luis Gracia Copyright © 2013 Elena Ibarz et al. All rights reserved. Assessment of Genotoxic and Cytotoxic Hazards in Brain and Bone Marrow Cells of Newborn Rats Exposed to Extremely Low-Frequency Magnetic Field Tue, 02 Oct 2012 13:18:48 +0000 http://www.hindawi.com/journals/bmri/2012/716023/ The present study aimed to evaluate the association between whole body exposure to extremely low frequency magnetic field (ELF-MF) and genotoxic , cytotoxic hazards in brain and bone marrow cells of newborn rats. Newborn rats (10 days after delivery) were exposed continuously to 50 Hz, 0.5 mT for 30 days. The control group was treated as the exposed one with the sole difference that the rats were not exposed to magnetic field. Comet assay was used to quantify the level of DNA damage in isolated brain cells. Also bone marrow cells were flushed out to assess micronucleus induction and mitotic index. Spectrophotometric methods were used to measure the level of malondialdehyde (MDA) and the activity of glutathione (GSH) and superoxide dismutase (SOD). The results showed a significant increase in the mean tail moment indicating DNA damage in exposed group (š‘ƒ<0.01,0.001,0.0001). Moreover ELF-MF exposure induced a significant (š‘ƒ<0.01,0.001) four folds increase in the induction of micronucleus and about three folds increase in mitotic index (š‘ƒ<0.0001). Additionally newborn rats exposed to ELF-MF showed significant higher levels of MDA and SOD (š‘ƒ<0.05). Meanwhile ELF-MF failed to alter the activity of GSH. In conclusion, the present study suggests an association between DNA damage and ELF-MF exposure in newborn rats. Monira M. Rageh, Reem H. EL-Gebaly, and Nihal S. El-Bialy Copyright © 2012 Monira M. Rageh et al. All rights reserved. Production of Chemoenzymatic Catalyzed Monoepoxide Biolubricant: Optimization and Physicochemical Characteristics Thu, 19 Jan 2012 13:37:05 +0000 http://www.hindawi.com/journals/bmri/2012/693848/ Linoleic acid (LA) is converted to per-carboxylic acid catalyzed by an immobilized lipase from Candida antarctica (Novozym 435). This per-carboxylic acid is only intermediate and epoxidized itself in good yields and almost without consecutive reactions. Monoepoxide linoleic acid 9(12)-10(13)-monoepoxy 12(9)-octadecanoic acid (MEOA) was optimized using D-optimal design. At optimum conditions, higher yield% (82.14) and medium oxirane oxygen content (OOC) (4.91%) of MEOA were predicted at 15 μL of H2O2, 120 mg of Novozym 435, and 7 h of reaction time. In order to develop better-quality biolubricants, pour point (PP), flash point (FP), viscosity index (VI), and oxidative stability (OT) were determined for LA and MEOA. The results showed that MEOA exhibited good low-temperature behavior with PP of āˆ’41āˆ˜C. FP of MEOA increased to 128āˆ˜C comparing with 115āˆ˜C of LA. In a similar fashion, VI for LA was 224 generally several hundred centistokes (cSt) more viscous than MEOA 130.8. The ability of a substance to resist oxidative degradation is another important property for biolubricants. Therefore, LA and MEOA were screened to measure their OT which was observed at 189 and 168āˆ˜C, respectively. Jumat Salimon, Nadia Salih, and Bashar Mudhaffar Abdullah Copyright © 2012 Jumat Salimon et al. All rights reserved. Optical Biosensors: A Revolution Towards Quantum Nanoscale Electronics Device Fabrication Sat, 29 Oct 2011 12:36:34 +0000 http://www.hindawi.com/journals/bmri/2011/348218/ The dimension of biomolecules is of few nanometers, so the biomolecular devices ought to be of that range so a better understanding about the performance of the electronic biomolecular devices can be obtained at nanoscale. Development of optical biomolecular device is a new move towards revolution of nano-bioelectronics. Optical biosensor is one of such nano-biomolecular devices that has a potential to pave a new dimension of research and device fabrication in the field of optical and biomedical fields. This paper is a very small report about optical biosensor and its development and importance in various fields. D. Dey and T. Goswami Copyright © 2011 D. Dey and T. Goswami. All rights reserved. Separation and Identification of HSP-Associated Protein Complexes from Pancreatic Cancer Cell Lines Using 2D CN/SDS-PAGE Coupled with Mass Spectrometry Wed, 19 Oct 2011 13:46:06 +0000 http://www.hindawi.com/journals/bmri/2011/193052/ Protein complexes are a cornerstone of many biological processes and together they form various types of molecular machinery. A broad understanding of these protein complexes is crucial for revealing and building models of protein function and regulation. Pancreatic cancer is a highly lethal disease which is difficult to diagnose at early stage and even more difficult to cure. In this study, we applied a gradient clear native gel system combined with subsequent second-dimensional SDS-PAGE to separate protein complexes from cell lysates of SW1990 and PANC-1 pancreatic cancer cell lines with different degrees of differentiation. Ten heat-shock-protein- (HSP-) associated protein complexes were separated and identified, and the differentially expressed proteins related to cancers were also found, such as HSP60, protein disulfide-isomerase A4 (ERp72), and transitional endoplasmic reticulum ATPase (TER ATPase). Zhiyun Zhao, Hui Liu, Xinli Wang, Xiaodong Wang, and Zhili Li Copyright © 2011 Zhiyun Zhao et al. All rights reserved. Separation of Normal and Premalignant Cervical Epithelial Cells Using Confocal Light Absorption and Scattering Spectroscopic Microscopy Ex Vivo Mon, 10 Oct 2011 19:14:53 +0000 http://www.hindawi.com/journals/bmri/2011/214781/ Confocal light absorption and scattering spectroscopic (CLASS) microscopy can detect changes in biochemicals and the morphology of cells. It is therefore used to detect high-grade cervical squamous intraepithelial lesion (HSIL) cells in the diagnosis of premalignant cervical lesions. Forty cervical samples from women with abnormal Pap smear test results were collected, and twenty cases were diagnosed as HSIL; the rest were normal or low-grade cervical squamous intraepithelial lesion (LSIL). The enlarged and condensed nuclei of HSIL cells as viewed under CLASS microscopy were much brighter and bigger than those of non-HSIL cells. Cytological elastic scattered light data was then collected at wavelengths between 400 and 1000 nm. Between 600 nm to 800 nm, the relative elastic scattered light intensity of HSIL cells was higher than that of the non-HSIL. Relative intensity peaks occurred at 700 nm and 800 nm. CLASS sensitivity and specificity results for HSIL and non-HSIL compared to cytology diagnoses were 80% and 90%, respectively. This study demonstrated that CLASS microscopy could effectively detect cervical precancerous lesions. Further study will verify this conclusion before the method is used in clinic for early detection of cervical cancer. Ling Yang, Wen-Tao Liu, Hao Wu, Cheng Wang, Bo Ping, and Da-Ren Shi Copyright © 2011 Ling Yang et al. All rights reserved. Real-Time Monitoring of Neural Differentiation of Human Mesenchymal Stem Cells by Electric Cell-Substrate Impedance Sensing Tue, 31 May 2011 15:13:56 +0000 http://www.hindawi.com/journals/bmri/2011/485173/ Stem cells are useful for cell replacement therapy. Stem cell differentiation must be monitored thoroughly and precisely prior to transplantation. In this study we evaluated the usefulness of electric cell-substrate impedance sensing (ECIS) for in vitro real-time monitoring of neural differentiation of human mesenchymal stem cells (hMSCs). We cultured hMSCs in neural differentiation media (NDM) for 6 days and examined the time-course of impedance changes with an ECIS array. We also monitored the expression of markers for neural differentiation, total cell count, and cell cycle profiles. Cellular expression of neuron and oligodendrocyte markers increased. The resistance value of cells cultured in NDM was automatically measured in real-time and found to increase much more slowly over time compared to cells cultured in non-differentiation media. The relatively slow resistance changes observed in differentiating MSCs were determined to be due to their lower growth capacity achieved by induction of cell cycle arrest in G0/G1. Overall results suggest that the relatively slow change in resistance values measured by ECIS method can be used as a parameter for slowly growing neural-differentiating cells. However, to enhance the competence of ECIS for in vitro real-time monitoring of neural differentiation of MSCs, more elaborate studies are needed. Hyo Eun Park, Donghee Kim, Hyun Sook Koh, Sungbo Cho, Jung-Suk Sung, and Jae Young Kim Copyright Ā© 2011 Hyo Eun Park et al. All rights reserved. Electrodelivery of Drugs into Cancer Cells in the Presence of Poloxamer 188 Sun, 25 Jul 2010 10:15:25 +0000 http://www.hindawi.com/journals/bmri/2010/314213/ In the present study it is shown that poloxamer 188, added before or immediately after an electrical pulse used for electroporation, decreases the number of dead cells and at the same time does not reduce the number of reversible electropores through which small molecules (cisplatin, bleomycin, or propidium iodide) can pass/diffuse. It was suggested that hydrophobic sections of poloxamer 188 molecules are incorporated into the edges of pores and that their hydrophilic parts act as brushy pore structures. The formation of brushy pores may reduce the expansion of pores and delay the irreversible electropermeability. Tumors were implanted subcutaneously in both flanks of nude mice using HeLa cells, transfected with genes for red fluorescent protein and luciferase. The volume of tumors stopped to grow after electrochemotherapy and the use of poloxamer 188 reduced the edema near the electrode and around the subcutaneously growing tumors. Iana Tsoneva, Iordan Iordanov, Annette J. Berger, Toma Tomov, Biliana Nikolova, Nikola Mudrov, and Martin R. Berger Copyright © 2010 Iana Tsoneva et al. All rights reserved. The Roles of Platelet GPIIb/IIIa and Ī±vĪ²3 Integrins during HeLa Cells Adhesion, Migration, and Invasion to Monolayer Endothelium under Static and Dynamic Shear Flow Wed, 28 Oct 2009 13:05:05 +0000 http://www.hindawi.com/journals/bmri/2009/829243/ During their passage through the circulatory system, tumor cells undergo extensive interactions with various host cells including endothelial cells and platelets. Mechanisms mediating tumor cell adhesion, migration, and metastasis to vessel wall under flow condition are largely unknown. The aim of this study was to investigate the potential roles of GPIIb/IIIa and integrins underlying the HeLa-endothelium interaction in static and dynamic flow conditions. HeLa cell migration and invasion were studied by using Millicell cell culture insert system. The numbers of transmigrated or invaded HeLa cells significantly increased by thrombin-activated platelets and reduced by eptifibatide, a platelet inhibitor. Meanwhile, RGDWE peptides, a specific inhibitor of integrin, also inhibited HeLa cell transmigration. Interestingly, the presence of endothelial cells had significant effect on HeLa cell migration regardless of static or cocultured flow condition. The adhesion capability of HeLa cells to endothelial monolayer was also significantly affected by GPIIb/IIIa and integrins. The arrested HeLa cells increased nearly 5-fold in the presence of thrombin-activated platelets at shear stress condition (1.84 dyn/cm2 exposure for 1 hour) than the control (static). Our findings showed that GPIIb/IIIa and integrins are important mediators in the pathology of cervical cancer and provide a molecular basis for the future therapy, and the efficient antitumor benefit should target multiple receptors on tumor cells and platelets. Yiyao Liu, Fenglong Zhao, Wentian Gu, Haishiu Yang, Quoquan Meng, Yunxiang Zhang, Hong Yang, and Qi Duan Copyright © 2009 Yiyao Liu et al. All rights reserved. Concentration Polarization of High-Density Lipoprotein and Its Relation with Shear Stress in an In Vitro Model Thu, 10 Sep 2009 11:48:38 +0000 http://www.hindawi.com/journals/bmri/2009/695838/ The purpose of this study was to determine the concentration polarization of high-density lipoprotein (HDL) at the surface of the carotid artery under conditions of steady flow and to establish its relationship with shear stress using an in vitro vascular simulation model of carotid bifurcation. Shear stress, HDL concentration at the surface, and the ratio of HDL concentration at the surface to concentration in bulk flow were measured at different locations within the model under high-speed (1.451 m/s) and low-speed (0.559 m/s) flow. HDL showed concentration polarization at the surface of the carotid artery model, particularly in the internal carotid artery sinus. With decreasing flow velocity, the shear stress at the surface also decreased, and HDL concentration polarization increased. The concentration polarization of HDL was negatively and strongly correlated with shear stress at both low- (, ) and high-speed flow (, ). Wei Meng, Fengxu Yu, Huaiqing Chen, Jianmin Zhang, Eryong Zhang, Ke Dian, and Yingkang Shi Copyright © 2009 Wei Meng et al. All rights reserved. Effects of Condylar Elastic Properties to Temporomandibular Joint Stress Sun, 26 Jul 2009 15:21:52 +0000 http://www.hindawi.com/journals/bmri/2009/509848/ Mandibular condyle plays an important role in the growth and reconstruction of the temporomandibular joint (TMJ). We aimed to obtain orthotropic elastic parameters of the condyle using a continuous-wave ultrasonic technique and to observe the effects of condylar elastic parameters on stress distribution of the TMJ using finite element analysis (FEA). Using the ultrasonic technique, all nine elastic parameters were obtained, which showed that the mandibular condyle was orthotropic. With the condyle defined as orthotropic, the occlusal stress was transferred fluently and uniformly from the mandible to the TMJ. The stress distribution in the isotropic model showed stepped variation among different anatomical structures with higher stress values in the cartilage and condyle than in the orthotropic model. We conclude that anisotropy has subtle yet significant effects on stress distribution of the TMJ and could improve the reality of simulations. Min Zhang, Takahiro Ono, Yongjin Chen, Xin Lv, Shun Wu, Hong Song, Ruini Zhao, and Yibing Wang Copyright © 2009 Min Zhang et al. All rights reserved. Effect of Chlorotriphenyl Derivatives of Sn and Pb upon Biophysical Properties of Membranes Tue, 07 Jul 2009 11:28:31 +0000 http://www.hindawi.com/journals/bmri/2009/969480/ Biophysical activity of two twin organometallic compounds Triphenyltin chloride (TPhT) and Triphenyllead chloride (TPhL) in their interreaction with model membranes, as well as with yeast cells Saccharomyces cerevisiae, was investigated. Four measurement methods were used in the experiments: two physical methods (spin probes method and the electric method); two biological methods (minimal inhibitory concentration /MIC/ and yeast survival test). It has been found that the activity of TPhT in interaction with model membranes and yeast cells is distinctly greater than that of TPhL. The activity manifests itself by considerable increase in the fluidity of the middle part of liposome bilayer, change in the polarization direction of the transmembrane voltage of filters impregnated with lauric acid, and in complete inhibition of growth of yeast cells at the concentration of 5 šœ‡g/mL. Dariusz Man, Marian Podolak, Grzegorz Engel, and Ewa Boniewska Copyright © 2009 Dariusz Man et al. All rights reserved. Effect of Fluid Shear Stress on Endocytosis of Heparan Sulfate and Low-density Lipoproteins Thu, 24 Jan 2008 00:00:00 +0000 http://www.hindawi.com/journals/bmri/2007/065136/abs/ Hemodynamic stress is a critical factor in the onset of atherosclerosis such that reduced rates of shear stress occurring at regions of high curvature are more prone to disease. The level of shear stress has direct influence on the thickness and integrity of the glycocalyx layer. Here we show that heparan sulfate, the main component of the glycocalyx layer, forms an intact layer only on cell surfaces subjected to shear, and not under static conditions. Furthermore, receptor-mediated endocytosis of heparan sulfate and low-density liporoteins is not detectable in cells exposed to shear stress. The internalized heparan sulfate and low-density lipoproteins are colocalized as shown by confocal imaging. Irmeli Barkefors, Cyrus K. Aidun, and E. M. Ulrika Egertsdotter Copyright © 2007 Irmeli Barkefors et al. All rights reserved. The Physical Basis of Medicine Mon, 01 Jan 1900 00:00:00 +0000 http://www.hindawi.com/journals/bmri/2003/160269/abs/ Abraham F. Jalbout Copyright © 2003 Hindawi Publishing Corporation. All rights reserved.