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Contrast Test (contrast + test)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Patent Foramen Ovale: Comparison among Diagnostic Strategies in Cryptogenic Stroke and Migraine

ECHOCARDIOGRAPHY, Issue 5 2009
Concetta Zito M.D.
Objective: The aim of this study was to compare transthoracic echocardiography (TTE) and transcranial Doppler ultrasonography (TCD) with transesophageal echocardiography (TEE) in order to define the best clinical approach to patent foramen ovale (PFO) detection. Methods: In total, 72 consecutive patients (33 men) with a mean age of 49 ± 13 years were prospectively enrolled. The TEE indication was cryptogenic stroke (36 patients) or migraine (36 patients, 22 with aura). All patients underwent standard TTE, TCD, and TEE examination. For any study, a contrast test was carried on using an agitated saline solution mixed with urea-linked gelatine (Haemaccel), injected as a rapid bolus via a right antecubital vein. A prolonged Valsalva maneuver was performed to improve test sensitivity. Results: TEE identified a PFO in 65% of the whole population: 56.5% in the migraine cohort and 43.5% in the cryptogenic stroke cohort. TTE was able to detect a PFO in 55% of patients positive at TEE (54% negative predictive value, 100% positive predictive value, 55% sensitivity, and 100% specificity). TCD was able to identify a PFO in 97% of patients positive at TEE (89% negative predictive value, 98% positive predictive value, 94% sensitivity, and 96% specificity). Conclusions: In patients with cryptogenic stroke and migraine, there is a fair concordance (k = 0.89) between TCD and TEE in PFO recognition. Accordingly, TCD should be recommended as a simple, noninvasive, and reliable technique, whereas TEE indication should be restricted to selected patients. TTE is a very specific technique, whose major advantage is the ability to detect a large right-to-left shunt, particularly if associated with an atrial septal aneurysm. [source]

Prenatal Alcohol Exposure and Chronic Mild Stress Differentially Alter Depressive- and Anxiety-Like Behaviors in Male and Female Offspring

ALCOHOLISM, Issue 4 2010
Kim G. C. Hellemans
Background:, Fetal Alcohol Spectrum Disorder (FASD) is associated with numerous neurobehavioral alterations, as well as disabilities in a number of domains, including a high incidence of depression and anxiety disorders. Prenatal alcohol exposure (PAE) also alters hypothalamic-pituitary-adrenal (HPA) function, resulting in increased responsiveness to stressors and HPA dysregulation in adulthood. Interestingly, data suggest that pre-existing HPA abnormalities may be a major contributory factor to some forms of depression, particularly when an individual is exposed to stressors later in life. We tested the hypothesis that exposure to stressors in adulthood may unmask an increased vulnerability to depressive- and anxiety-like behaviors in PAE animals. Methods:, Male and female offspring from prenatal alcohol (PAE), pair-fed (PF), and ad libitum-fed control (C) treatment groups were tested in adulthood. Animals were exposed to 10 consecutive days of chronic mild stress (CMS), and assessed in a battery of well-validated tasks sensitive to differences in depressive- and/or anxiety-like behaviors. Results:, We report here that the combination of PAE and CMS in adulthood increases depressive- and anxiety-like behaviors in a sexually dimorphic manner. PAE males showed impaired hedonic responsivity (sucrose contrast test), locomotor hyperactivity (open field), and alterations in affiliative and nonaffiliative social behaviors (social interaction test) compared to control males. By contrast, PAE and, to a lesser extent, PF, females showed greater levels of "behavioral despair" in the forced swim test, and PAE females showed altered behavior in the final 5 minutes of the social interaction test compared to control females. Conclusions:, These data support the possibility that stress may be a mediating or contributing factor in the psychopathologies reported in FASD populations. [source]

New paediatric contrast test: Hiding Heidi low-contrast ,face' test

CLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 5 2003
Clinical Research
ABSTRACT Background:,The Hiding Heidi low-contrast ,face' test is a new paediatric contrast test to evaluate the ability to detect objects with low contrast. The purpose of the present study was to compare the Hiding Heidi low-contrast ,face' test (HH) with the Pelli,Robson contrast sensitivity test (PR) and the functional acuity contrast test (FACT) in the low-contrast assessment. Methods:,Thirty university students participated in the present study. The contrast ability was evaluated by using three different methods: HH, PR and FACT. The HH was repeated on two separate occasions to test the repeatability. Results:,There was a significant positive correlation between HH and PR (r = 0.65, P < 0.01); between HH and FACT at 6 cycles per degree (c.p.d.; r = 0.64, P < 0.01); between HH and FACT at 3 c.p.d. (r = 0.91, P < 0.01); and between HH and FACT at 1.5 c.p.d. (r = 0.56, P < 0.01). The paired t -test showed a significant difference between HH and PR (t = ,6.05, P < 0.01); between HH and FACT at 6 c.p.d. (t = ,11.16, P < 0.01); between HH and FACT at 3 c.p.d. (t = ,8.35, P < 0.01); and between HH and FACT at 1.5 c.p.d. (t = ,5.64, P < 0.01). They had good agreement. The HH had a high repeatability. Conclusions:,The HH had a positive correlation but produced significantly different readings when compared with FACT and PR. The features and role of HH in clinical contrast sensitivity assessment are discussed. [source]

Closure Procedures for Monotone Bi-Factorial Dose,Response Designs

BIOMETRICS, Issue 1 2005
M. Hellmich
Summary Two goals of multiple-dose factorial trials are (i) demonstrating improved effectiveness of a fixed combination over each of its components as well as (ii) identifying a safe and effective dose range. The authors address both goals though with focus on the second by closure procedures that guarantee strong control of the familywise error rate. Two different families of null hypotheses are investigated for bi-factorial dose,response designs that are monotone with respect to the matrix partial order. One is suitable to find the minimum effective dose(s) and the other one is large enough to identify the highest effective dose step(s). Likelihood ratio tests and appropriate multiple contrast tests are applied to an unbalanced clinical trial example taken from Hung (2000, Statistics in Medicine19, 2079,2087). Full computer code written in the R language is available from the Internet. [source]