Search results for "stiffness"
showing 10 items of 524 documents
Is local stiffness, as measured by radio frequency, more sensitive than intima-media thickness?
2013
Aim: The aim of our study was to explore the changes in common carotid arterial intima-media thickness (CCA IMT) and local arterial stiffness to evaluate, non-invasively, early vascular disease in patients with cardiovascular (CV) risk factors and "normal" carotid IMT (6.05 m/s better identified, among patients with IMT <0.9mm, those with cardiovascular risk factors (sensitivity 82.0 % specificity 62.0 %; AUC 0.73). Conclusion. Increased stiffness is a result of change both in quantity and quality of the arterial wall. Arterial functional changes and distention alterations may herald the onset of vascular disease before manifestation of symptoms or detection of preclinical atherosclerotic l…
Possible misclassification of cardiovascular risk by SCORE in antisynthetase syndrome: results of the pilot multicenter study RI.CAR.D.A
2020
Abstract Objectives To test the ability of an established traditional cardiovascular (CV) risk prediction score [Systematic COronary Risk Evaluation (SCORE)] and its EULAR modified version (mSCORE) to identify antisynthetase syndrome (ASyS) patients at high CV risk and to examine for the first time associations of CV and cerebrovascular surrogate markers with clinical and immunological ASyS parameters. Methods SCORE/mSCORE and the gold standard marker of aortic stiffness [carotid-femoral pulse wave velocity (cfPWV)] were examined in ASyS patients and healthy controls. Moreover, sonography of the common- (CCA) and internal- (ICA) carotid arteries was performed in subsets of both groups, eval…
Suboptimal performance of APRI and FIB-4 in ruling out significant fibrosis and confirming cirrhosis in HIV/HCV co-infected and HCV mono-infected pat…
2018
Purpose: We aimed to assess the diagnostic reliability of two indirect biomarkers, APRI and FIB-4, for the staging of liver fibrosis using transient elastography (TE) as reference standard, among HIV/HCV co-infected and HCV mono-infected patients. Methods: This is an observational, retrospective study on subjects who had access to the RESIST HCV from October 2013 to December 2016, a regional network encompassing 22 hospitals and academic centers throughout Sicily. Sensitivity, specificity and diagnostic accuracy of indirect biomarkers for liver stiffness measurement (LSM) < 9.5 kPa (significant fibrosis) and LSM ≥ 12.5 kPa (cirrhosis) were determined by receiver operator characteristics …
Insulin resistance is a major determinant of liver stiffness in nondiabetic patients with HCV genotype 1 chronic hepatitis.
2009
BACKGROUND: In patients with chronic hepatitis C (CHC), liver stiffness measurement (LSM) by transient elastography (TE), is closely related to the stage of fibrosis, but may be affected by necroinflammation. Other factors, such as insulin resistance (IR), might influence the performance of LSM. AIMS: To evaluate in a cohort of nondiabetic patients with genotype 1 CHC, whether IR and other anthropometric, biochemical, metabolic and histological factors contribute to LSM and to identify the best cut-off values of LSM for predicting different stages of fibrosis. METHODS: Nondiabetic patients with genotype 1 CHC (n = 156) were evaluated by liver biopsy (Metavir score), anthropometric, biochemi…
Serial combination of non-invasive tools improves the diagnostic accuracy of severe liver fibrosis in patients with NAFLD
2017
SummaryBackground The accuracy of available non-invasive tools for staging severe fibrosis in patients with nonalcoholic fatty liver disease (NAFLD) is still limited. Aim To assess the diagnostic performance of paired or serial combination of non-invasive tools in NAFLD patients. Methods We analysed data from 741 patients with a histological diagnosis of NAFLD. The GGT/PLT, APRI, AST/ALT, BARD, FIB-4, and NAFLD Fibrosis Score (NFS) scores were calculated according to published algorithms. Liver stiffness measurement (LSM) was performed by FibroScan. Results LSM, NFS and FIB-4 were the best non-invasive tools for staging F3-F4 fibrosis (AUC 0.863, 0.774, and 0.792, respectively), with LSM ha…
Changes in mechanical properties of human plantar flexor muscles in ageing
2003
Changes in contractile and elastic properties of human plantar flexor muscles in ageing, were investigated in 12 young (19-24 years, YG) and 11 old (61-74 year, OG) men. Maximal isometric and concentric voluntary torques, at several angular velocities, were measured to construct torque-angular velocity relationship. This led to the calculation of an index of maximal shorting velocity (VImax) at low torque. Two methods were then used to calculate musculotendinous (MT, quick-release movements) and musculoarticular (MA, sinusoidal perturbations) stiffness. In both cases, stiffness was linearly related to torque, leading to the calculation of a stiffness index (SI) as the slope of the stiffness…
Age-related muscle activation profiles and joint stiffness regulation in repetitive hopping
2011
Abstract It is well documented that increasing effort during exercise is characterized by an increase in electromyographic activity of the relevant muscles. How aging influences this relationship is a matter of great interest. In the present study, nine young and 24 elderly subjects did repetitive hopping with maximal effort as well as with 50%, 65%, 75% and 90% intensities. During hopping joint kinematics were measured together with electromyographic activity (EMG) from the soleus, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles. The results showed that agonist activation increased in both age groups with increasing intensity. The highest jumping efficiency (E…
Grip force regulates hand impedance to optimize object stability in high impact loads
2011
Anticipatory grip force adjustments are a prime example of the predictive nature of motor control. An object held in precision grip is stabilized by fine adjustments of the grip force against changes in tangential load force arising from inertia during acceleration and deceleration. When an object is subject to sudden impact loads, prediction becomes critical as the time available for sensory feedback is very short. Here, we investigated the control of grip force when participants performed a targeted tapping task with a hand-held object. During the initial transport phase of the movement, load force varied smoothly with acceleration. In contrast, in the collision, load forces sharply incre…
Abnormal BAEP and internal auditory canal MRI in intracranial hypotension
2017
Intracranial hypotension (IH) is a treatable condition due to cerebrospinal fluid leak, characterised by variable clinical and MRI findings.1 Positional headache, neck stiffness, hearing changes with subdural fluid collection, enhancement of meninges, engorgement of venous structures and brain sagging are among the most frequent clinical and MRI findings. Typical abnormalities are found in 68%–85% of patients1. Hearing alterations (ranging from misperception to severe hearing loss) are known clinical symptoms of IH.1 The mechanism involves secondary perilymph depression due to patency of the cochlear aqueduct, inducing a compensatory expansion of the endolymphatic compartment, decreasing ba…
In-Vivo Estimation and Repeatability of Force-Length Relationship and Stiffness of the Human Achilles Tendon using Phase Contrast MRI
2008
Purpose To devise a method using velocity encoded phase contrast MRI and MR-compatible dynamometry, for in vivo estimation of elastic properties of the human Achilles tendon and to assess within-session and day-to-day repeatability of this technique. Materials and Methods Achilles tendon force and calcaneus-movement-adjusted displacement were measured during a submaximal isometric plantarflexion in 4 healthy subjects, four repeated trials each. The measured force-length (F-L) relationship was least-squares fitted to a cubic polynomial. Typical error was calculated for tendon displacement at multiple force levels, stiffness from the “linear region,” and transition point from the displacement…