Search for: pathophysiological
Total 56 records
Urine and serum NMR-based metabolomics in pre-procedural prediction of contrast-induced nephropathy, Article Internal and Emergency Medicine ; Volume 15, Issue 1 , 2020 , Pages 95-103 ; Chashmniam, S ; Khoormizi, S. M. H ; Salehi, L ; Jamalian, S. A ; Nafar, M ; Kalantari, S ; Sharif University of Technology
Contrast induced nephropathy (CIN) has been reported to be the third foremost cause of acute renal failure. Metabolomics is a robust technique that has been used to identify potential biomarkers for the prediction of renal damage. We aim to analyze the serum and urine metabolites changes, before and after using contrast for coronary angiography, to determine if metabolomics can predict early development of CIN. 66 patients undergoing elective coronary angiography were eligible for enrollment. Urine and serum samples were collected prior to administration of CM and 72 h post procedure and analyzed by nuclear magnetic resonance. The significant differential metabolites between patients who...
Trunk coordination in healthy and chronic nonspecific low back pain subjects during repetitive flexion-extension tasks: Effects of movement asymmetry, velocity and load, Article Human Movement Science ; Volume 45 , 2016 , Pages 182-192 ; 01679457 (ISSN) ; Sanjari, M. A ; Chehrehrazi, M ; Kahrizi, S ; Parnianpour, M ; Sharif University of Technology
Multiple joint interactions are critical to produce stable coordinated movements and can be influenced by low back pain and task conditions. Inter-segmental coordination pattern and variability were assessed in subjects with and without chronic nonspecific low back pain (CNSLBP). Kinematic data were collected from 22 CNSLBP and 22 healthy volunteers during repeated trunk flexion-extension in various conditions of symmetry, velocity, and loading; each at two levels. Sagittal plane angular data were time normalized and used to calculate continuous relative phase for each data point. Mean absolute relative phase (MARP) and deviation phase (DP) were derived to quantify lumbar-pelvis and...
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...
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 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...
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...
The influence of new reciprocating link medial linkage orthosis on walking and independence in a spinal cord injury patient, Article Spinal Cord ; Volume 53 , October , 2015 , Pages S10-S12 ; 13624393 (ISSN) ; Arazpour, M ; Farahmand, F ; Azmand, A ; Hutchins, S. W ; Vahab Kashani, R ; Mousavi, M. E ; Sharif University of Technology
Nature Publishing Group 2015
Objectives: The purpose of this paper is to describe the development and evaluation of a new medial linkage reciprocating gait orthosis (MLRGO) that incorporates a reciprocal mechanism and is sensitive to pelvic motion to potentially assist paraplegic patients to walk and provide functional independence. Case description and methods: The new orthosis was constructed and tested by a 20-year-old female paraplegic subject with transverse myelitis at T10 level, who was 4 years post injury and had also been an isocentric reciprocating gait orthosis (IRGO) user for 2 years. She received gait training for 12 weeks before undertaking gait analysis, and also completed a questionnaire that was...
The effects of trochlear groove geometry on patellofemoral joint stability - A computer model study, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 222, Issue 1 , 2008 , Pages 75-88 ; 09544119 (ISSN) ; Farahmand, F ; Meghdari, A ; Sharif University of Technology
The effect of the variation in the femoral groove geometry on patellofemoral joint stability was studied using a two dimensional transverse plane model with deformable articular surfaces. The femoral and patellar bony structures were modelled as rigid bodies with their profiles expressed by splines. The articular cartilage was discretized into compression springs, distributed along the femoral and patellar profiles, based on the rigid-body spring model. The medial and lateral retinacula were modelled as linear tensile springs, and the quadriceps muscles and patellar tendon as strings with known tension. The anatomical data were obtained from the transverse plane magnetic resonance images of...
The effects of movement speed on kinematic variability and dynamic stability of the trunk in healthy individuals and low back pain patients, Article Clinical Biomechanics ; Volume 30, Issue 7 , Aug , 2015 , Pages 682-688 ; 02680033 (ISSN) ; Sanjari, M. A ; Mokhtarinia, H. R ; Moeini Sedeh, S ; Khalaf, K ; Parnianpour, M ; Sharif University of Technology
Elsevier Ltd 2015
Background: Comparison of the kinematic variability and dynamic stability of the trunk between healthy and low back pain patient groups can contribute to gaining valuable information about the movement patterns and neuromotor strategies involved in various movement tasks. Methods: Fourteen chronic low back pain patients with mild symptoms and twelve healthy male volunteers performed repeated trunk flexion-extension movements in the sagittal plane at three different speeds: 20 cycles/min, self-selected, and 40 cycles/min. Mean standard deviations, coefficient of variation and variance ratio as variability measures; maximum finite-time Lyapunov exponents and maximum Floquet multipliers as...
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...
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...
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...
Synthetic ECG generation and bayesian filtering using a Gaussian wave-based dynamical model, Article Physiological Measurement ; Volume 31, Issue 10 , 2010 , Pages 1309-1329 ; 09673334 (ISSN) ; Shamsollahi, M. B ; Clifford, G. D ; Sharif University of Technology
In this paper, we describe a Gaussian wave-based state space to model the temporal dynamics of electrocardiogram (ECG) signals. It is shown that this model may be effectively used for generating synthetic ECGs as well as separate characteristic waves (CWs) such as the atrial and ventricular complexes. The model uses separate state variables for each CW, i.e. P, QRS and T, and hence is capable of generating individual synthetic CWs as well as realistic ECG signals. The model is therefore useful for generating arrhythmias. Simulations of sinus bradycardia, sinus tachycardia, ventricular flutter, atrial fibrillation and ventricular tachycardia are presented. In addition, discrete versions of...
Synchronizability of EEG-based functional networks in early alzheimer's disease, Article IEEE Transactions on Neural Systems and Rehabilitation Engineering ; Volume 20, Issue 5 , 2012 , Pages 636-641 ; 15344320 (ISSN) ; Jalili, M ; Knyazeva, M. G ; Sharif University of Technology
Recently graph theory and complex networks have been widely used as a mean to model functionality of the brain. Among different neuroimaging techniques available for constructing the brain functional networks, electroencephalography (EEG) with its high temporal resolution is a useful instrument of the analysis of functional interdependencies between different brain regions. Alzheimer's disease (AD) is a neurodegenerative disease, which leads to substantial cognitive decline, and eventually, dementia in aged people. To achieve a deeper insight into the behavior of functional cerebral networks in AD, here we study their synchronizability in 17 newly diagnosed AD patients compared to 17 healthy...
Switching kalman filter based methods for apnea bradycardia detection from ECG signals, Article Physiological Measurement ; Volume 36, Issue 9 , 2015 , Pages 1763-1783 ; 09673334 (ISSN) ; Shamsollahi, M. B ; Ge, D ; Hernandez, A. I ; Sharif University of Technology
Apnea bradycardia (AB) is an outcome of apnea occurrence in preterm infants and is an observable phenomenon in cardiovascular signals. Early detection of apnea in infants under monitoring is a critical challenge for the early intervention of nurses. In this paper, we introduce two switching Kalman filter (SKF) based methods for AB detection using electrocardiogram (ECG) signal. The first SKF model uses McSharry's ECG dynamical model integrated in two Kalman filter (KF) models trained for normal and AB intervals. Whereas the second SKF model is established by using only the RR sequence extracted from ECG and two AR models to be fitted in normal and AB intervals. In both SKF approaches, a...
Studying the effect of kinematical pattern on the mechanical performance of paraplegic gait with reciprocating orthosis, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 226, Issue 8 , 2012 , Pages 600-611 ; 09544119 (ISSN) ; Farahmand, F ; Salarieh, H ; Sharif University of Technology
Paraplegic users of mechanical walking orthoses, e.g. advanced reciprocating gait orthosis (ARGO), often face high energy expenditure and extreme upper body loading during locomotion. We studied the effect of kinematical pattern on the mechanical performance of paraplegic locomotion, in search for an improved gait pattern that leads to lower muscular efforts. A three-dimensional, four segment, six-degrees-of-freedom skeletal model of the advanced reciprocating gait orthosis-assisted paraplegic locomotion was developed based on the data acquired from an experimental study on a single subject. The effect of muscles was represented by ideal joint torque generators. A response surface analysis...
Search for critical loading condition of the spine-A meta analysis of a nonlinear viscoelastic finite element model, Article Computer Methods in Biomechanics and Biomedical Engineering ; Volume 8, Issue 5 , 2005 , Pages 323-330 ; 10255842 (ISSN) ; Shirazi Adl, A ; Parnianpour, M ; Sharif University of Technology
The relative vulnerability of spinal motion segments to different loading combinations remains unknown. The meta-analysis described here using the results of a validated L2-L3 nonlinear viscoelastic finite element model was designed to investigate the critical loading and its effect on the internal mechanics of the human lumbar spine. A Box-Behnken experimental design was used to design the magnitude of seven independent variables associated with loads, rotations and velocity of motion. Subsequently, an optimization method was used to find the primary and secondary variables that influence spine mechanical output related to facet forces, disc pressure, ligament forces, annulus matrix...
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...
Rhythmic air-puff into nasal cavity modulates activity across multiple brain areas: A non-invasive brain stimulation method to reduce ventilator-induced memory impairment, Article Respiratory Physiology and Neurobiology ; Volume 287 , 2021 ; 15699048 (ISSN) ; Salimi, M ; Nazari, M ; Garousi, M ; Tabasi, F ; Dehdar, K ; Salimi, A ; Jamaati, H ; Mirnajafi Zadeh, J ; Arabzadeh, E ; Raoufy, M. R ; Sharif University of Technology
Elsevier B.V 2021
Mechanical ventilation (MV) can result in long-term brain impairments that are resistant to treatment. The mechanisms underlying MV-induced brain function impairment remain unclear. Since nasal airflow modulates brain activity, here we evaluated whether reinstating airflow during MV could influence the memory performance of rats after recovery. Rats were allocated into two study groups: one group received rhythmic air-puff into the nasal cavity during MV and a control group that underwent ventilation without air-puff. During MV, air-puffs induced time-locked event potentials in OB, mPFC and vHPC and significantly increased the oscillatory activity at the air-puff frequency. Furthermore, in...
Relative efficiency of abdominal muscles in spine stability, Article Computer Methods in Biomechanics and Biomedical Engineering ; Volume 11, Issue 3 , 2008 , Pages 291-299 ; 10255842 (ISSN) ; Shirazi Adl, A ; Parnianpour, M ; Sharif University of Technology
Using an iterative kinematics-driven nonlinear finite element model, relative efficiency of individual abdominal muscles in spinal stability in upright standing posture was investigated. Effect of load height on stability and muscle activities was also computed under different coactivity levels in abdominal muscles. The internal oblique was the most efficient muscle (compared with the external oblique and rectus abdominus) in providing stability while generating smaller spinal loads with lower fatigue rate of muscles. As the weight was held higher, stability deteriorated requiring additional flexor-extensor activities. The stabilising efficacy of abdominal muscles diminished at higher...