Search results for "Reference"
showing 10 items of 2491 documents
Variations in central corneal thickness during the menstrual cycle in women.
2007
PURPOSE: We report changes in the central corneal thickness during various phases of the menstrual cycle. METHODS: We recruited 16 healthy women of reproductive age and measured the central corneal thickness at 3 points in their menstrual cycle, beginning on days 1 to 3 and again at ovulation and at the end of the cycle (days 27-32). Ovulation was determined with a test that determines the peak of luteinizing hormone in the urine. RESULTS: We found that the central cornea was thinnest at the beginning of the cycle (mean = 536 microm). Corneal thickness increased at ovulation (mean = 549 microm) and at the end of the cycle (mean = 559 microm). The difference in corneal thickness was statisti…
Uterine effects of clomiphene citrate in women with polycystic ovary syndrome: a prospective controlled study
2006
Background Previous data on the efficacy of clomiphene citrate, the most commonly used drug for treating anovulatory infertility in patients with polycystic ovary syndrome (PCOS), have shown a discrepancy between ovulation and pregnancy rates. In the present subanalysis (of a larger previously published randomized controlled trial), the effect of clomiphene citrate on several ultrasonographic markers of uterine receptivity in PCOS patients who ovulated under treatment was studied. Methods Thirty-three PCOS women who ovulated under 150 mg daily clomiphene citrate and 33 healthy controls were studied. Uterine, subendometrial and endometrial blood flows, endometrial thickness and pattern were …
Fibrinolytic parameters in normotensive pregnancy with intrauterine fetal growth retardation and in severe preeclampsia
1991
In pregnancy a decrease in fibrinolytic activity, which is due to an increase in plasminogen activator inhibitor activity and plasminogen activator inhibitor type 1 and type 2, has been described. Because the placenta is a source of both type 1 and type 2 plasminogen activator inhibitor, we have studied them and other fibrinolytic parameters in a group of normotensive pregnant women with intrauterine fetal growth retardation and in two groups of women with preeclampsia, with or without intrauterine growth retardation. A significant increase in plasminogen activator inhibitor type 1 antigen and plasminogen activator inhibitor activity was observed in preeclampsia, with or without intrauterin…
Multicenter validation of the magnetic resonance t2* technique for segmental and global quantification of myocardial iron
2009
Purpose To assess the transferability of the magnetic resonance imaging (MRI) multislice multiecho T2* technique for global and segmental measurement of iron overload in thalassemia patients. Materials and Methods Multiecho T2* sequences were installed on six MRI scanners. Five healthy subjects (n = 30) were scanned at each site; five thalassemia major (TM) patients were scanned at the reference site and were rescanned locally (n = 25) within 1 month. T2* images were analyzed using previously validated software. Results T2* values of healthy subjects showed intersite homogeneity. On TM patients, for global heart T2* values the correlation coefficient was 0.97, coefficients of variation (CoV…
Eye position tunes the contribution of allocentric and egocentric information to target localization in human goal-directed arm movements.
1997
Subjects were required to point to the distant vertex of the closed and the open configurations of the Muller-Lyer illusion using either their right hand (experiment 1) or their left hand (experiment 2). In both experiments the Muller-Lyer figures were horizontally presented either in the left or in the right hemispace and movements were executed using either foveal or peripheral vision of the target. According to the illusion effect, subjects undershot and overshot the vertex location of the closed and the open configuration, respectively. The illusion effect decreased when the target was fixated and when the stimulus was positioned in the right hemispace. These results confirm the hypothe…
Elements of Significance Testing with Equivalence Problems
1991
AbstractThe paper outlines an approach to the general methodological problem of equivalence assessment which is based on the classical theory of testing statistical hypotheses. Within this frame of reference it is natural to search for decision rules satisfying the same criteria of optimality which are customarily applied in deriving solutions to one- and two-sided testing problems. For three standard situations very frequently encountered in medical applications of statistics, a concise account of such an optimal test for equivalence is presented. It is pointed out that tests based on the well-known principle of confidence interval inclusion are valid in the sense 1 of guaranteeing the pre…
Reference Standards for Software Evaluation
1990
AbstractThe field of automated ECG analysis was one of the earliest topics in Medical Informatics and may be regarded as a model both for computer-assisted medical diagnosis and for evaluating medical diagnostic programs. The CSE project has set reference standards of two kinds: In a broad sense, a standard how to perform a comprehensive evaluation study, in a narrow sense, standards as specific references for evaluating computer ECG programs. The evaluation methodology used within the CSE project is described as a basis for presentation of results which are published elsewhere in this issue.
Age-dependent inbreeding risk and offspring fitness costs in female black grouse
2011
Dispersal is an important mechanism used to avoid inbreeding. However, dispersal may only be effective for part of an individual's lifespan since, post-dispersal individuals that breed over multiple reproductive events may risk mating with kin of the philopatric sex as they age. We tested this hypothesis in black grouse Tetrao tetrix , and show that yearling females never mated with close relatives whereas older females did. However, matings were not with direct kin suggesting that short-distance dispersal to sites containing kin and subsequent overlap of reproductive lifespans between males and females were causing this pattern. Chick mass was lower when kinship was high, suggesting impor…
Plasma lipid, apolipoprotein and Lp(a) levels in elderly normolipidemic women: Relationships with coronary heart disease and longevity
1995
The relation between plasma lipids and coronary heart disease (CHD) in the elderly is still debated, as well as the proposed role of lipoproteins as markers of longevity. In this study both normolipidemic elderly and middle-aged women with CHD showed higher triglycerides and apolipoprotein B levels and lower high-density lipoprotein (HDL)-cholesterol and apolipoprotein A-I levels in comparison with age-matched subjects without CHD. In the middle-aged group, hypertension and HDL-cholesterol levels and, in the elderly group, only HDL-cholesterol levels were independently associated with CHD. No significant difference was found between a group of healthy centenarians and elderly and middle-age…
What are the roles of calorie restriction and diet quality in promoting healthy longevity?
2014
Epidemiological and experimental data indicate that diet plays a central role in the pathogenesis of many age-associated chronic diseases, and in the biology of aging itself. Data from several animal studies suggest that the degree and time of calorie restriction (CR) onset, the timing of food intake as well as diet composition, play major roles in promoting health and longevity, breaking the old dogma that only calorie intake is important in extending healthy lifespan. Data from human studies indicate that long-term CR with adequate intake of nutrients results in several metabolic adaptations that reduce the risk of developing type 2 diabetes, hypertension, cardiovascular disease and cance…