Search results for "volunteers"

Evidence-based medicine and the problem of healthy volunteers

2017

Abstract Healthy controls are subjects without the disease being studied but may have other conditions indirectly affecting outcome. In the present epidemics of obesity a few subjects with undiagnosed nonalcoholic fatty liver disease enter clinical studies as controls, producing biased results. Stricter selection criteria should be considered to prevent this risk.

Two-dimensional analysis of tear protein patterns of diabetic patients

2001

In diabetic patients, dry eye and other ocular surface diseases occur more often than in healthy subjects. The aim of this study was to analyze the tear protein patterns of patients suffering from diabetes mellitus type II (dia) and to compare them to the patterns of healthy volunteers (ctrl). Tear proteins of nonstimulated tears of 20 patients (ctrl n=10, dia n=10) were separated using two-dimensional electrophoretic techniques. The protein patterns of each group were analyzed by a multivariate analysis of discriminance. Furthermore, for all spots of each gel, a 50 x 50 variables pH/Mr (molecular weight) array was generated and subsequently analyzed by a multivariate analysis of discrimina…

Effects of Age and Sex on Optic Nerve Sheath Diameter in Healthy Volunteers and Patients With Traumatic Brain Injury.

2020

The measurement of optic nerve sheath diameter (ONSD) has been reported as a non-invasive marker for intracranial pressure (ICP). Nevertheless, it is uncertain whether possible ONSD differences occur with age and sex in healthy and brain-injured populations. The aim of this study was to investigate the effects of sex and age on ONSD in healthy volunteers and patients with traumatic brain injury. We prospectively included 122 healthy adult volunteers (Galliera Hospital, Genova, Italy), and compared age/sex dependence of ONSD to 95 adult patients (Addenbrooke's Hospital, Cambridge, UK) with severe traumatic brain injury (TBI) requiring intubation and invasive ICP monitoring. The two groups we…

Effect of liraglutide on intragastric pressure (IGP) and satiation during intragastric nutrient drink infusion in healthy volunteers

2011

Detection of central circuits implicated in the formation of novel pain memories

2016

Jaymin Upadhyay,1 Julia Granitzka,1 Thomas Bauermann,2 Ulf Baumgärtner,3 Markus Breimhorst,1 Rolf-Detlef Treede,3 Frank Birklein1 1Department of Neurology, 2Department of Neuroradiology, University Medical Centre, Johannes Gutenberg University Mainz, Mainz, 3Department of Neurophysiology, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Mannheim, Germany Abstract: Being able to remember physically and emotionally painful events in one’s own past may shape behavior, and can create an aversion to a variety of situations. Pain imagination is a related process that may include recall of past experiences, in addition to production of sensor…

Transcranial direct current stimulation: Adverse effects and the efficacy of a commonly utilised sham protocol

2017

IntroductionTranscranial direct current stimulation (tDCS) is a promising neuromodulation method that has, for example, been used to treat depression. Nevertheless, the adverse effects of tDCS and the validity of the current standard tDCS sham protocols have received limited attention.ObjectivesTo evaluate the extent and types of tDCS adverse effects and to assess the reliability of sham stimulation as a control procedure for tDCS in a double-blind setting.AimsTo compare adverse effects between tDCS and sham stimulation groups, and to determine how well the participants and the experimenter are able to distinguish tDCS from sham stimulation.MethodsA sample of healthy volunteers received a 2…

Systematic analysis of esophageal pressure topography in high-resolution manometry of 68 normal volunteers

2013

Summary The introduction of high-resolution manometry (HRM) has been a significant advance in esophageal diagnostics. Normative values however are currently based upon a single set of published reference values, and multiple new metrics have been added over the past several years. Our goal was to provide a second set of ‘normal-values’ and to include all current metrics suggested by the 2012 Chicago classification. Sixty-eight subjects without foregut symptoms or previous surgery (median age 25.5 years, ranging from 20–58 years, 53% female) underwent esophageal motility assessment via an established standardized protocol. Normative thresholds were calculated for esophago-gastric junction (E…

Quantitative Tissue Doppler Echocardiography: Physiological Nonuniformity of Left Ventricular Transmural Myocardial Wall-Motion Velocities and Gradie…

2001

Tissue Doppler echocardiography (TDE) is a new method by which transmural myocardial function can be studied noninvasively. In order to investigate physiology and reproducibility, 24 young, healthy volunteers were examined by M-mode TDE. Nonuniformity of transmural tissue layer velocities became apparent: Subendocardial and subepicardial velocities of the anteroseptal myocardial wall (AW) were 3.5 +/- 0.7 and 1.3 +/- 0.5 cm/sec (P < 0.0001, t-test), whereas in the posterolateral wall (PW) values of 3.6 +/- 0.6 and 1.2 +/- 0.4 cm/sec (P < 0.0001, t-test), respectively, were revealed. The ratios, termed "myocardial velocity gradients" as a new indicator of left ventricular performance, were 3…

Dual channel photoplethysmography studies of cardio-vascular response to the body position changes

2005

The dual-channel photoplethysmography studies of physiological responses during 3-stage orthostatic test were performed. Clear differences in heartbeat rate, pulse wave transit time and blood pressure variations of healthy volunteers and diabetic patients have been observed.

Energy spectral density as valid parameter to compare postural control between subjects with nonspecific chronic low back pain vs healthy subjects : …

2021

Abstract Background Nonspecific chronic low back pain (NSCLBP) is one of the most common and frequent health problems. Objetive to compare postural control (i.e. center of pressure (CoP) displacement and energy spectral density (ESD)) using technological devices (accelerometers and pressure platform) between subjects with NSCLBP and healthy subjects. Methods A cross-sectional case-control study was conducted. Observational study (STROBE). The final sample consisted of 60 subjects (30 NSCLBP subjects and 30 healthy subjects). Triaxial accelerometer and pressure platform were used in order to obtain ESD and CoP displacement measurements during four balance tasks (i.e. with and without vision …