Search results for "Healthy subject"
showing 10 items of 195 documents
Redundant and synergistic information transfer in cardiovascular and cardiorespiratory variability
2015
In the framework of information dynamics, new tools are emerging which allow one to quantify how the information provided by two source processes about a target process results from the contribution of each source and from the interaction between the sources. We present the first implementation of these tools in the assessment of short-term cardiovascular and cardiorespiratory variability, by introducing two strategies for the decomposition of the information transferred to heart period (HP) variability from systolic arterial pressure (SAP) and respiration flow (RF) variability. Several measures based on the notion of transfer entropy (TE) are defined to quantify joint, individual and redun…
Intra and intersession repeatability and reliability of the S-Plate® pressure platform.
2017
Abstract Aim The aim of this study was to assess the repeatability and reliability of the S-Plate® pressure platform in a group of healthy subjects. Material and methods Forty subjects, free from physical conditions that would affect normal gait, walked along a five-meter corridor while data were recorded from the pressure platform. A total of 10 steps (five each side) were obtained as well as five static trials; the same measurements were repeated one week later. Peak and mean plantar pressures and contact area were recorded for both dynamic and static trials. Additionally, weight supported on each limb was documented during static trials. To assess intrasession and intersession repeatabil…
Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload.
2011
Purpose To evaluate the effectiveness of the single ROI approach for the detection of hepatic iron burden in thalassemia major (TM) patients in respect to a whole liver measurement. Materials and Methods Five transverse hepatic slices were acquired by a T2* gradient-echo sequence in 101 TM patients and 20 healthy subjects. The T2* value was calculated in a single region of interest (ROI) defined in the medium-hepatic slice. Moreover, the T2* value was extracted on each of the eight ROIs defined in the functionally independent segments. The mean hepatic T2* value was calculated. Results For patients, the mean T2* values over segments VII and VIII were significantly lower. This pattern was su…
Impact of Corneoscleral Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconic Eyes
2019
Objective To analyze the changes in corneal biomechanical parameters of keratoconic eyes with and without intracorneal ring segment (ICRS) implants after 1 year of corneoscleral contact lens (CScL) wear. Methods Seventy-four eyes of 74 patients were divided into three groups: healthy subjects (29 eyes, control group), and 2 groups of subjects with keratoconic eyes (one group of 20 eyes with ICRS implants and one of 25 eyes without them), which were fitted with CScL. Corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc) were evaluated before fitting CScL and after 1 year of CScL wear. In addition, endothelial cell count (ECC) and centr…
Comparison of Macular Thickness in Patients with Keratoconus and Control Subjects Using the Cirrus HD-OCT
2014
Purpose.The aim of the present study was to compare macular thickness in patients with keratoconus (KC) with macular thickness in healthy subjects.Subjects and Methods.Twenty-six patients with KC and 52 control subjects were included. The macular structure was evaluated using a Zeiss Cirrus HD-OCT. The scan pattern used was 512 × 128, which covers an area of approximately 6 × 6 mm of the retina. The cube volume was assessed as well as macular thickness in each of the 9 sectors defined by the software.Results.The mean signal strength was significantly lower in the KC group (mean 8.4, range 6–10) compared with the control group (mean 9.7, range 7–10),P<0.0001(unpairedt-test). There were no…
Oxyphytosterols are present in plasma of healthy human subjects
2004
The oxidised derivatives of phytosterols (oxyphytosterols) were identified in plasma samples from thirteen healthy human volunteers, using MS. All the samples contained noticeable quantities of (24R)-5b,6b-epoxy-24-ethylcholestan-3b-ol (b-epoxysitostanol) and (24R)-ethylcholestan-3b,5a,6b-triol (sitostanetriol) and also trace levels of (24R)-5a,6a-epoxy-24-ethylcholestan-3b-ol (a-epoxysitostanol), (24R)-methylcholestan-3b,5a,6b-triol (campestanetriol) and (24R)-ethylch olest-5-en-3b-ol-7-one(7-ketositosterol). The amounts of these oxyphytosterols in plasma varied from 4·8 to 57·2 ng/ml. There are two possibilities concerning the origin of these compounds. First, they could come from the sma…
Effects of suppressing neutral and obsession-like thoughts in normal subjects: beyond frequency
2004
Abstract Recent cognitive-behavioral theories on obsessive–compulsive disorder (OCD) show that deliberate attempts to suppress intrusive and undesirable thoughts lie at the genesis of clinical obsessions. In this paper the results of an experimental study on the suppression of neutral and obsession-like thoughts in normal subjects are presented. Eighty-seven university students performed in three experimental periods: (1) base-line monitoring, (2) experimental instruction, and (3) monitoring. For each of these periods, the frequency of the occurrence of a “white bear” thought or a personally relevant intrusive thought was registered. Half of the subjects received instructions to suppress th…
Differential effect of Incobotulinumtoxin A on pain, neurogenic flare and hyperalgesia in human surrogate models of neurogenic pain
2017
Background: The effectiveness of Botulinum-neurotoxin A (BoNT/A) to treat pain in human pain models is very divergent. This study was conducted to clarify if the pain models or the route of BoNT/A application might be responsible for these divergent findings. Methods: Sixteen healthy subjects (8 males, mean age 27 ± 5 years) were included in a first set of experiments consisting of three visits: (1) Visit: Quantitative sensory testing (QST) was performed before and after intradermal capsaicin injection (CAPS, 15 μg) on one thigh and electrical current stimulation (ES, 1 Hz) on the contralateral thigh. During stimulation pain and the neurogenic flare response (laser-Doppler imaging) were ass…
Deep pain thresholds in the distal limbs of healthy human subjects.
2003
Pressure pain thresholds (PPTs) in distal limbs have been under-investigated despite their potential clinical importance. Therefore, we compared PPTs over nail bed, bony prominences, and muscle in distal parts of upper and lower limbs. We investigated 12 healthy subjects using three handheld devices: a spring-loaded, analogue pressure threshold meter (PTM) with two operating ranges, and an electronic Algometer. PPTs were determined with three series of ascending stimulus intensities with a ramp of about 50 kPa/s. PPTs were normally distributed in logarithmic space. PPTs over different tissues varied significantly (ANOVA, p0.001): mean thresholds and 95% confidence intervals were 615 kPa (26…
Pressure pain thresholds: Subject factors and the meaning of peak pressures.
2017
Background The assessment of pressure pain has become an integral part in pain research. The distribution of pressure under a plunger can be uneven. However, measurements based on conventional devices show the applied force or mean pressure, failing to take local pressure peaks into account. Our main question was whether peak pressures under the probe are responsible for pain onset. Methods A force-controlled algometer was fitted with a newly developed pressure-indicating film. Pressure pain thresholds (PPTs) of 100 healthy subjects (57 men, age 18-66 years) were assessed at 29 sites across the body. Each site was measured three times, nonconsecutively and presented in randomized order. For…