Search for: pathophysiological
Total 56 records
Fluid–structure interaction simulation of a cerebral aneurysm: effects of endovascular coiling treatment and aneurysm wall thickening, Article Journal of the Mechanical Behavior of Biomedical Materials ; Volume 74 , 2017 , Pages 72-83 ; 17516161 (ISSN) ; Nejad, M. A ; Saeedi, M ; Sharif University of Technology
In the present study, we investigate the effect of the hemodynamic factors of the blood flow on the cerebral aneurysms. To this end, a hypothetical geometry of the aneurysm in the circle of Willis, located in the bifurcation point of the anterior cerebral artery (ACA) and anterior communicating artery (ACoA) is modeled in a three-dimensional manner. Three cases are chosen in the current study: an untreated thin wall (first case), untreated thick wall (second case), and a treated aneurysm (third case). The effect of increasing the aneurysm wall thickness on the deformation and stress distribution of the walls are studied. The obtained results showed that in the second case, a reduction in the...
Comparison of the trunk-pelvis and lower extremities sagittal plane inter-segmental coordination and variability during walking in persons with and without chronic low back pain, Article Human Movement Science ; Volume 52 , 2017 , Pages 55-66 ; 01679457 (ISSN) ; Kamali, F ; Razeghi, M ; Haghpanah, S. A ; Sharif University of Technology
Elsevier B.V 2017
Inter-segmental coordination can be influenced by chronic low back pain (CLBP). The sagittal plane lower extremities inter-segmental coordination pattern and variability, in conjunction with the pelvis and trunk, were assessed in subjects with and without non-specific CLBP during free-speed walking. Kinematic data were collected from 10 non-specific CLBP and 10 non-CLBP control volunteers while the subjects were walking at their preferred speed. Sagittal plane time-normalized segmental angles and velocities were used to calculate continuous relative phase for each data point. Mean absolute relative phase (MARP) and deviation phase (DP) were derived to quantify the trunk-pelvis and bilateral...
A regenerative approach towards recovering the mechanical properties of degenerated intervertebral discs: Genipin and platelet-rich plasma therapies, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 231, Issue 2 , 2017 , Pages 127-137 ; 09544119 (ISSN) ; Wang, J. L ; Abdollahi, M ; Hsu, Y. C ; Parnianpour, M ; Khalaf, K ; Sharif University of Technology
SAGE Publications Ltd 2017
Degenerative disc disease, associated with discrete structural changes in the peripheral annulus and vertebral endplate, is one of the most common pathological triggers of acute and chronic low back pain, significantly depreciating an individual's quality of life and instigating huge socioeconomic costs. Novel emerging therapeutic techniques are hence of great interest to both research and clinical communities alike. Exogenous crosslinking, such as Genipin, and platelet-rich plasma therapies have been recently demonstrated encouraging results for the repair and regeneration of degenerated discs, but there remains a knowledge gap regarding the quantitative degree of effectiveness and...
Goal equivalent manifold analysis of task performance in non-specific LBP and healthy subjects during repetitive trunk movement; effect of load, velocity, symmetry, Article Human Movement Science ; Volume 51 , 2017 , Pages 72-81 ; 01679457 (ISSN) ; Sanjari, M. A ; Mokhtarinia, H. R ; Jamshidi, A. A ; Maroufi, N ; Parnianpour, M ; Sharif University of Technology
Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions. Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP). Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading;...
Article Tumor Biology ; Volume 39, Issue 6 , 2017 ; 10104283 (ISSN) ; Mostafaei, S ; Yari, K ; Ghasemi, A ; Chenar, H. M ; Moghoofei, M ; Sharif University of Technology
Human parvovirus B19 (B19) is a small, non-enveloped virus and belongs to Parvoviridae family. B19 persists in many tissues such as thyroid tissue and even thyroid cancer. The main aim of this study was to determine the presence of B19, its association with increased inflammation in thyroid tissue, and thus its possible role in thyroid cancer progression. Studies have shown that virus replication in non-permissive tissue leads to overexpression of non-structural protein and results in upregulation of proinflammatory cytokines such as interleukin 6 and tumor necrosis factor alpha. A total of 36 paraffin-embedded thyroid specimens and serum were collected from patients and 12 samples were used...
The effect of functional bracing on the arthrokinematics of anterior cruciate ligament injured knees during lunge exercise, Article Gait and Posture ; Volume 63 , 2018 , Pages 52-57 ; 09666362 (ISSN) ; Farahmand, F ; Esfandiarpour, F ; Golestanha, S. A ; Akbar, M ; Eskandari, A ; Mousavi, S. E ; Sharif University of Technology
Elsevier B.V 2018
Background: Functional knee braces are extensively used for partially and completely torn anterior cruciate ligament (ACL) patients and those who have undergone ACL graft reconstruction, in order to support the healing ACL, improve the joint's functional stability, and restore the normal joint kinematics. Research question: Does wearing braces alter the arthrokinematics of the ACL deficient knees during lung exercise? Methods: For ten male unilateral ACL deficient subjects, 3D knee models were reconstructed from CT images, acquired in rest position. Sagittal plane fluoroscopy was then performed throughout a complete cycle of lunge in braced and non-braced conditions. The 3D kinematics of the...
Article Advanced Drug Delivery Reviews ; Volume 127 , 2018 , Pages 138-166 ; 0169409X (ISSN) ; Rinoldi, C ; Schot, M ; Saheb Kashaf, S ; Sharifi, F ; Jalilian, E ; Nuutila, K ; Giatsidis, G ; Mostafalu, P ; Derakhshandeh, H ; Yue, K ; Swieszkowski, W ; Memic, A ; Tamayol, A ; Khademhosseini, A ; Sharif University of Technology
Elsevier B.V 2018
Chronic, non-healing wounds place a significant burden on patients and healthcare systems, resulting in impaired mobility, limb amputation, or even death. Chronic wounds result from a disruption in the highly orchestrated cascade of events involved in wound closure. Significant advances in our understanding of the pathophysiology of chronic wounds have resulted in the development of drugs designed to target different aspects of the impaired processes. However, the hostility of the wound environment rich in degradative enzymes and its elevated pH, combined with differences in the time scales of different physiological processes involved in tissue regeneration require the use of effective drug...
The effects of anxiety and external attentional focus on postural control in patients with Parkinson’s disease, Article PLoS ONE ; Volume 13, Issue 2 , 2018 ; 19326203 (ISSN) ; Azad, A ; Mehdizadeh, H ; Habibi, S. A ; Mandehgary Najafabadi, M ; Saberi, Z. S ; Rahimzadegan, H ; Moradi, S ; Behzadipour, S ; Parnianpour, M ; Taghizadeh, G ; Khalaf, K ; Sharif University of Technology
Public Library of Science 2018
Background Although anxiety is a common non-motor outcome of Parkinson's disease (PD) affecting 40% of patients, little attention has been paid so far to its effects on balance impairment and postural control. Improvement of postural control through focusing on the environment (i.e. external focus) has been reported, but the role of anxiety, as a confounding variable, remains unclear. Objectives This study aimed to investigate the influence of anxiety and attentional focus instruction on the standing postural control of PD patients. Methods Thirty-four patients with PD (17 with high anxiety (HA-PD) and 17 with low anxiety (LA-PD)), as well as 17 gender- and age-matched healthy control...
Role and significance of trunk and upper extremity muscles in walker-assisted paraplegic gait: a case study, Article Topics in Spinal Cord Injury Rehabilitation ; Volume 24, Issue 1 , 2018 , Pages 18-27 ; 10820744 (ISSN) ; Farahmand, F ; Arazpour, M ; Zohoor, H ; Sharif University of Technology
Thomas Land Publishers Inc 2018
Background and Purpose: Understanding the role and significance of trunk and upper extremity muscles in paraplegic gait can help in designing more effective assistive devices for these patients and also provides valuable information for improving muscle strengthening programs. Methods: In a patient with a spinal cord injury (SCI) who could walk independently (rating scale of ambulatory capacity, 9) with the aid of bilateral ankle-foot orthosis and a walker, the kinematics, kinetics and electromyographic (EMG) activities of 16 muscles from the trunk and upper and lower extremities were recorded during gait. The onset, cessation, and duration of the EMG signal were associated with the 4 phases...
Article Computer Methods and Programs in Biomedicine ; Volume 157 , 2018 , Pages 129-136 ; 01692607 (ISSN) ; Montazeri Ghahjaverestan, N ; Shamsollahi, M. B ; Jutten, C ; Sharif University of Technology
Elsevier Ireland Ltd 2018
In this paper, we propose a novel method for extracting fiducial points (FPs) of the beats in electrocardiogram (ECG) signals using switching Kalman filter (SKF). In this method, according to McSharry's model, ECG waveforms (P-wave, QRS complex and T-wave) are modeled with Gaussian functions and ECG baselines are modeled with first order auto regressive models. In the proposed method, a discrete state variable called “switch” is considered that affects only the observation equations. We denote a mode as a specific observation equation and switch changes between 7 modes and corresponds to different segments of an ECG beat. At each time instant, the probability of each mode is calculated and...
The effect of angle and level of exertion on trunk neuromuscular performance during multidirectional isometric activities, Article Spine ; Volume 34, Issue 5 , 2009 , Pages E170-E177 ; 03622436 (ISSN) ; Olyaei, G. R ; Talebian, S ; Sanjari, M. A ; Parnianpour, M ; Sharif University of Technology
STUDY DESIGN.: To quantify trunk muscle capability and controllability in different angles and levels of isometric exertion using a torque tracking system. OBJECTIVE.: To investigate the effect of biaxial isometric exertions on the maximum capability of trunk and to examine the effect of angle and level of isometric exertion on trunk controllability during the tracking task in upright posture. SUMMARY OF BACKGROUND DATA.: Combined motions of trunk at varying exertion levels occur in most daily and occupational activities and are important risk factors of low back pain. Few studies have investigated trunk capability and controllability during multidirectional activities with different...
Translation and validation study of the Persian version of the Arthritis Impact Measurement Scales 2 (AIMS2) in patients with osteoarthritis of the knee, Article BMC Musculoskeletal Disorders ; Volume 10, Issue 1 , 2009 ; 14712474 (ISSN) ; Parnianpour, M ; Askary Ashtiani, A. R ; Hadian, M. R ; Rostamian, A ; Montazeri, A ; Sharif University of Technology
Background. The Arthritis Impact Measurement Scales 2 (AIMS2) has not been translated and validated for Persian-speaking patients with osteoarthritis of the knee. This was to provide a validated instrument to measure functional disability and health-related quality of life in patients with osteoarthritis of the knee in Iran. The aim of this study was to culturally adapt and validate the AIMS2 for Persian-speaking patients with osteoarthritis of the knee in Iran. Methods. A consecutive sample of patients with knee osteoarthritis were asked to complete the AIMS2, the Short Form Health Survey (SF-36) and four visual analog scales for pain, joint stiffness, patient's and physician's global...
Mechanical characterization of the ligaments in subject-specific models of the patellofemoral joint using in vivo laxity tests, Article Knee ; Volume 26, Issue 6 , 2019 , Pages 1220-1233 ; 09680160 (ISSN) ; Farahmand, F ; Arjmand, N ; Sharif University of Technology
Elsevier B.V 2019
Background: The purpose of this study was to propose a methodology for mechanical characterization of the ligaments in subject-specific models of the patellofemoral joint (PFJ) of living individuals. Method: PFJ laxity tests were performed on a healthy volunteer using a specially designed loading apparatus under biplane fluoroscopy. A three-dimensional (3D) parametric model of the PFJ was developed in the framework of the rigid body spring model using the geometrical data acquired from the subject's computed tomography and magnetic resonance images. The stiffness and pre-strains of the medial and lateral PFJ ligaments were characterized using a two-step optimization procedure which minimized...
Recent advances in the design and applications of amyloid-β peptide aggregation inhibitors for Alzheimer’s disease therapy, Article Biophysical Reviews ; Volume 11, Issue 6 , 2019 , Pages 901-925 ; 18672450 (ISSN) ; Khazaei, S ; Behnammanesh, H ; Shamloo, A ; Erfani, M ; Beiki, D ; Bavi, O ; Sharif University of Technology
Alzheimer’s disease (AD) is an irreversible neurological disorder that progresses gradually and can cause severe cognitive and behavioral impairments. This disease is currently considered a social and economic incurable issue due to its complicated and multifactorial characteristics. Despite decades of extensive research, we still lack definitive AD diagnostic and effective therapeutic tools. Consequently, one of the most challenging subjects in modern medicine is the need for the development of new strategies for the treatment of AD. A large body of evidence indicates that amyloid-β (Aβ) peptide fibrillation plays a key role in the onset and progression of AD. Recent studies have reported...
Lower extremity kinematic analysis in male athletes with unilateral anterior cruciate reconstruction in a jump-landing task and its association with return to sport criteria, Article BMC Musculoskeletal Disorders ; Volume 20, Issue 1 , 2019 ; 14712474 (ISSN) ; Esfandiarpour, F ; Mehdizadeh, S ; Yousefzadeh, N. K ; Parnianpour, M ; Sharif University of Technology
BioMed Central Ltd 2019
Background: Return to sport (RTS) criteria are widely being used to identify anterior cruciate ligament reconstructed (ACLR) athletes ready to return to sportive activity and reduce risk of ACL re-injury. However, studies show a high rate of ACL re-injury in athletes who passed RTS criteria. This indicates that the current RTS criteria might not be sufficient to determine return to sport time in ACLR athletes. Previous studies have reported a close association between altered lower limb kinematics and ACL re-injury. However, it is not clear how lower extremity kinematics differs between ACLR athletes who passed the RTS-criteria and who failed. This study compared lower extremity kinematics...
The potential role of auditory prediction error in decompensated tinnitus: An auditory mismatch negativity study, Article Brain and Behavior ; Volume 9, Issue 4 , 2019 ; 21623279 (ISSN) ; Daneshi, A ; Asadpour, A ; Mohsen, S ; Farhadi, M ; Mahmoudian, S ; Sharif University of Technology
John Wiley and Sons Ltd 2019
Introduction: Some tinnitus subjects habituate to their tinnitus but some others do not and complain of its annoyance tremendously. Normal sensory memory and change detection processes are needed for detecting the tinnitus signal as a prediction error and habituation to tinnitus. The purpose of this study was to compare auditory mismatch negativity as the index of sensory memory and change detection among the studied groups to search for the factors involving in the perception of tinnitus and preventing habituation in decompensated tinnitus subjects. Methods: Electroencephalography was recorded from scalp electrodes in compensated tinnitus, decompensated tinnitus, and no tinnitus control...
Time-course investigation of postural sway variability: Does anxiety exacerbate the sensory reweighting impairment in chronic stroke survivors?, Article Neuropsychologia ; Volume 127 , 2019 , Pages 185-194 ; 00283932 (ISSN) ; Azad, A ; Mehdizadeh, H ; Doostdar, A ; Hoseinpour, F ; Mehdizadeh, M ; Niazi Khatoon, J ; Shokouhyan, M. R ; Parnianpour, M ; Taghizadeh, G ; Khalaf, K ; Sharif University of Technology
Elsevier Ltd 2019
Although anxiety is one of the most prevalent psychological disorders in stroke survivors, its effect on sensory reweighting has not yet been fully studied. The aim of this work was to investigate how anticipation of collision avoidance events affects sensory reweighting in chronic stroke survivors with low and high levels of anxiety (LA-stroke and HA-stroke, respectively), as compared with healthy controls (HC), under the condition of perturbed proprioception. Eighteen LA-stroke and 18 HA-stroke survivors, as well as 18 gender- and age-matched HC, participated in this study. Postural sway variability (i.e. Root Mean Square (RMS) of the COP velocity) was measured for a duration of 180 s...
The metabolomics signature associated with responsiveness to steroid therapy in focal segmental glomerulosclerosis: A pilot study, Article Revista de Investigacion Clinica ; Volume 71, Issue 2 , 2019 , Pages 106-115 ; 00348376 (ISSN) ; Kalantari, S ; Nafar, M ; Boroumandnia, N ; Sharif University of Technology
Instituto Nacional de la Nutricion Salvador Zubiran 2019
Background: Focal segmental glomerulosclerosis (FSGS) is considered one of the most severe glomerular diseases and around 80% of cases are resistant to steroid treatment. Since a large proportion of steroid-resistant (SR) FSGS patients progress to end-stage renal disease, other therapeutic strategies may benefit this population. However, identification of non-invasive biomarkers to predict this high-risk population is needed. Objective: We aimed to identify the biomarker candidates to distinguish SR from steroid-sensitive (SS) patients using metabolomics approach and to identify the possible molecular mechanism of resistance. Methods: Urine was collected from biopsy-proven FSGS patients...
Improvement of upper limb motor control and function after competitive and noncompetitive volleyball exercises in chronic stroke survivors: a randomized clinical trial, Article Archives of Physical Medicine and Rehabilitation ; Volume 100, Issue 3 , 2019 , Pages 401-411 ; 00039993 (ISSN) ; Azad, A ; Mehdizadeh, H ; Behzadipour, S ; Fakhar, M ; Taghavi Azar Sharabiani, P ; Parnianpour, M ; Taghizadeh, G ; Khalaf, K ; Sharif University of Technology
W.B. Saunders 2019
Objectives: To investigate the effects of competitive and noncompetitive volleyball exercises on the functional performance and motor control of the upper limbs in chronic stroke survivors. Design: Randomized clinical trial. Setting: Outpatient rehabilitation center. Participants: Chronic stroke survivors (N=48). Interventions: Participants were randomly assigned to competitive (n=16) or noncompetitive (n=16) volleyball exercise groups (60min/d volleyball exercise+30min/d traditional rehabilitation, 3d/wk for 7wk) and control group (n=16). Main Outcome Measures: Reach and grasp motor control measures were evaluated through kinematic analysis. Functional outcomes were assessed via Motor...
A stability-based model of a growing spine with adolescent idiopathic scoliosis: A combination of musculoskeletal and finite element approaches, Article Medical Engineering and Physics ; Volume 64 , 2019 , Pages 46-55 ; 13504533 (ISSN) ; Rouhi, G ; Arjmand, N ; Adeeb, S ; Sharif University of Technology
Elsevier Ltd 2019
Using a combined musculoskeletal and finite element (FE) approach, this study aimed to evaluate stability-based muscle forces in a spine with adolescent idiopathic scoliosis (AIS) as compared to a normal spine; and subsequently, determine the effects of stress distribution on the growth plates (GPs) of the growing spine. For this purpose a nonlinear 3D FE model of one normal and one scoliotic thoracolumbar spine, consisting of GPs attached to rigid L1 to L4 vertebrae, were developed using computed tomography images coupled with a growth modulation using the Stokes’ model. Corresponding well with recent in-vivo and in-vitro studies, results of the models predicted intradiscal pressures at the...