Search results for "specificity"
showing 10 items of 2234 documents
ENDOCRINE TUMOURS: Calcitonin in thyroid and extra-thyroid neuroendocrine neoplasms: the two-faced Janus.
2020
An increased calcitonin serum level is suggestive of a medullary thyroid cancer (MTC), but is not pathognomonic. The possibility of false positives or other calcitonin-secreting neuroendocrine neoplasms (NENs) should be considered. Serum calcitonin levels are generally assessed by immunoradiometric and chemiluminescent assays with high sensitivity and specificity; however, slightly moderately elevated levels could be attributable to various confounding factors. Calcitonin values >100 pg/mL are strongly suspicious of malignancy, whereas in patients with moderately elevated values (10–100 pg/mL) a stimulation test may be applied to improve diagnostic accuracy. Although the standard protoco…
Effects of diabetes definition on global surveillance of diabetes prevalence and diagnosis: a pooled analysis of 96 population-based studies with 331…
2015
Diabetes has been defined on the basis of different biomarkers, including fasting plasma glucose (FPG), 2-h plasma glucose in an oral glucose tolerance test (2hOGTT), and HbA1c. We assessed the effect of different diagnostic definitions on both the population prevalence of diabetes and the classification of previously undiagnosed individuals as having diabetes versus not having diabetes in a pooled analysis of data from population-based health examination surveys in different regions.
A comparative study of the sperm nuclear morphometry in cattle, goat, sheep, and pigs using a new computer-assisted method (CASMA-F)
2012
This study was designed to compare the sperm nuclear morphometry of four species of domestic artiodactyls (cattle, sheep, goats, and pigs), using the newly developed automatic computer-assisted sperm morphometry analysis-F. The study was divided into two experiments. In the first experiment, samples from 20 males from each species were collected, diluted, and divided into four sample aliquots. The first was labeled directly with Hoechst 33342, and the others were processed as smears. Between smears, one group was directly labeled with Hoechst after air drying, and the other was fixed either with glutaraldehyde (GLUT), or with methanol, and afterward labeled with Hoechst. Digital images of t…
Selective bilateral blood sampling from the inferior petrosal sinus in Cushing's disease: effects of corticotropin-releasing factor and thyrotropin-r…
1993
We sought to enhance the sensitivity of selective bilateral blood sampling to determine adrenocorticotropin (ACTH) and prolactin levels in the inferior petrosal sinus (IPS) by administering two stimulatory agents--corticotropin-releasing factor (CRF) and thyrotropin-releasing hormone (TRH). We then determined the ACTH and prolactin levels in the IPS of 10 patients with Cushing's disease. After peripheral administration of both CRF and TRH, ACTH levels were significantly higher on the tumor side in all patients. The prolactin level was significantly higher on the tumor side when CRF or TRH was used to stimulate pituitary secretion. Postsurgical immunohistochemistry studies revealed productio…
Clinical relevance of thyroid-stimulating autoantibodies in pediatric graves' disease-a multicenter study.
2014
Context and Objective: The incidence of TSH receptor (TSHR) stimulating autoantibodies (TSAbs) in pediatric Graves' disease (GD) is controversial. This large, multicenter study evaluated the clinical relevance of TSAbs in children with GD both with Graves' orbitopathy (GO) and without orbital disease. Design: We conducted a cross-sectional retrospective study. Setting: Sera were collected in seven American and European academic referral centers and evaluated in a central laboratory. Patients and Samples: A total of 422 serum samples from 157 children with GD, 101 control individuals with other thyroid and nonthyroid autoimmune diseases, and 50 healthy children were studied. Main Outcome Me…
Thyroid hormone controls carnitine status through modifications of gamma-butyrobetaine hydroxylase activity and gene expression.
2002
The carnitine system plays a key role in beta-oxidation of long-chain fatty acids by permitting their transport into the mitochondrial matrix. The effects of hypothyroidism and hyperthyroidism were studied on gamma-butyrobetaine hydroxylase (BBH), the enzyme responsible for carnitine biosynthesis in the rat. In rat liver, BBH activity was decreased in the hypothyroid state and increased in hyperthyroid animals. The modifications in BBH activity correlated with changes in the enzyme Vmax values. These changes were shown to be related to hepatic BBH mRNA abundance. Thyroid hormones are known to interact with lipid metabolism, in particular by increasing long-chain fatty acid oxidation through…
Sex differences in GABAA receptor binding in rat brain measured by an improved in vitro binding assay.
1990
The distribution of GABAA receptor sites was studied in female and male rat brain by an improved in vitro binding assay using 3H-muscimol and carefully washed membrane fractions. The binding studies revealed a single class of binding sites exhibiting the properties of GABAA receptors. The specific binding of 3H-muscimol was measured in four brain areas: the preoptic brain area, mediobasal hypothalamus, corticomedial amygdala and cerebral cortex. The equilibrium dissociation constants (KD) ranged from 11.2 to 23.3 nM in diestrous females and from 13.1 to 50.4 nM in males, the maximal number of binding sites (Bmax) from 3290 to 10240 fmol/mg protein in females and from 5495 to 17449 fmol/mg p…
Striated muscle-specific serine/threonine-protein kinase beta (SPEGβ) segregates with high- versus low-responsiveness to endurance exercise training
2019
Bidirectional selection for either high or low responsiveness to endurance running has created divergent rat phenotypes of high-response trainers (HRT) and low-response trainers (LRT). We conducted proteome profiling of HRT and LRT gastrocnemius of 10 female rats (body weight 279 ± 35 g; n = 5 LRT and n = 5 HRT) from generation 8 of selection. Differential analysis of soluble proteins from gastrocnemius was conducted by label-free quantitation. Genetic association studies were conducted in 384 Russian international-level athletes (age 23.8 ± 3.4 yr; 202 men and 182 women) stratified to endurance or power disciplines. Proteomic analysis encompassed 1,024 proteins, 76 of which exhibited stat…
Low Levels of Mitochondrial DNA and Symbiont Diversity in the Worldwide Agricultural Pest, the Greenhouse Whitefly Trialeurodes vaporariorum (Hemipte…
2015
Trialeurodes vaporariorum, the greenhouse whitefly, is a cosmopolitan agricultural pest. Little is known about the genetic diversity of T. vaporariorum and the bacterial symbionts associated with this species. Here, we undertook a large phylogeographic study by investigating both the mitochondrial (mt) diversity and the infection status of 38 T. vaporariorum collections from 18 countries around the world. Genetic diversity of T. vaporariorum was studied by analyzing sequence data from the mt cytochrome oxidase I, cytochrome b, and NADH dehydrogenase subunit 5 genes. Maximum-likelihood (ML) phylogeny reconstruction delineated 2 clades characterized by limited sequence divergence: one clade c…
Muscle fiber-type distribution predicts weight gain and unfavorable left ventricular geometry: a 19 year follow-up study
2006
Abstract Background Skeletal muscle consists of type-I (slow-twitch) and type-II (fast-twitch) fibers, with proportions highly variable between individuals and mostly determined by genetic factors. Cross-sectional studies have associated low percentage of type-I fibers (type-I%) with many cardiovascular risk factors. Methods We investigated whether baseline type-I% predicts left ventricular (LV) structure and function at 19-year follow-up, and if so, which are the strongest mediating factors. At baseline in 1984 muscle fiber-type distribution (by actomyosin ATPase staining) was studied in 63 healthy men (aged 32–58 years). The follow-up in 2003 included echocardiography, measurement of obes…