Citations

AbstractBackground: High-sensitivity cardiac troponin assays will augment the frequency of increased results, making important the determination of reference change values to distinguish acute from chronic increases. We assessed short- and long-term biological variability of cardiac troponin T (cTnT) in healthy subjects with a novel high-sensitivity (hs) assay.Methods: We collected blood from 20 healthy volunteers at 5 time points for short-term study and biweekly at 4 times from the same volunteers for long-term study. We analyzed serum samples in duplicate with a hscTnT assay on the Roche Modular E170 and computed reference change values (RCVs) for analytical, intraindividual, interindividual, and total change values (CVA, CVI, CVG, and CVT, respectively) and the index of individuality (II). We calculated RCVs by using a log-normal approach, owing to the skewed results of the data.Results: Short- and long-term CVA values were 53.5% and 98%. CVI and CVG were 48.2% and 85.9%, respectively, for short-term studies and 94% and 94% for long-term studies. Mean δ values for the within-day study were 58% and −57.5%, and between-day mean δ values were 103.4% and −87%. Within- and between-day IIs were 0.8 and 0.14, respectively.Conclusions: The biological variation demonstrated with the hscTnT assay is higher than prior data for cardiac troponin I. This may be attributed to differences in biology or assay imprecision at low concentrations. A short-term change (RCV log normal) of 85% and a long-term change of 315% is necessary to define a changing pattern.

Realizing education and awareness are paramount in making clinical trials available, the authors sought to evaluate a statewide navigation service to identify how it might improve cancer clinical trial accessibility in Florida for physicians and patients.

Pregnancy-associated plasma protein-A (PAPP-A) increases local IGF-I bioavailability through cleavage of inhibitory IGF binding protein (IGFBP)-4 in a variety of systems, including the cardiovascular system. To test the hypothesis that expression of PAPP-A promotes the development of atherosclerotic lesions, we generated transgenic mice that express human PAPP-A in arterial smooth muscle. Four founder lines were characterized for transgenic human PAPP-A mRNA and protein expression, IGFBP-4 protease activity, and tissue specificity. In study I, apolipoprotein E knockout (ApoE KO) mice, a well-characterized mouse model of atherosclerosis, and ApoE KO mice expressing the human PAPP-A transgene at relatively high levels (ApoE KO/Tg) were fed a high-fat diet. At harvest, aortas were dissected and opened longitudinally for en face staining of lipid-rich lesions. Lesion area was increased 3.5-fold in aortas from ApoE KO/Tg compared with ApoE KO mice ( P < 0.001), but no significant difference was seen in lesion number. In study II, replacement of PAPP-A expression in arterial smooth muscle of double ApoE KO/PAPP-A KO mice resulted in a 2.5-fold increase in lesion area ( P = 0.002), without an effect on lesion number. PAPP-A transgene expression was associated with a significant increase in an IGF-responsive gene ( P < 0.001), suggesting increased local IGF-I action. We therefore conclude that expression of human PAPP-A localized to arterial smooth muscle accelerates lesion progression in a mouse model of atherosclerosis. These data provide further evidence for the importance of PAPP-A in the cardiovascular system and suggest PAPP-A as a potential therapeutic target in the control of atherosclerosis.

Abstract A recent report indicated significant interference of naproxen with total bilirubin measurement when using the Jendrassik and Grof method. We explored the possibility of avoiding this interference by using a different method. We observed that naproxen has no effect on total bilirubin measurement by any method, but O-desmethylnaproxen (the naproxen metabolite) interfered significantly with total bilirubin assays using the Jendrassik and Grof method (Beckman Coulter [Brea, CA] and Siemens [Tarrytown, NY] bilirubin method). The Roche (Indianapolis, IN) bilirubin assay based on a different method was not affected. When serum samples of 9 patients receiving naproxen were analyzed for total bilirubin level, we observed good correlation in total bilirubin values measured by all 3 methods in 7 of 9 patients with therapeutic naproxen concentrations. In contrast, in 2 patients with elevated naproxen levels, the total bilirubin values observed by using the Beckman and Siemens methods were significantly higher than the value obtained by the Roche assay. The naproxen metabolite interferes with assays based on the Jendrassik and Grof method but not with the Roche bilirubin assay.

We retrospectively reviewed the first 14 patients who received preoperative paravertebral blockade prior to minimally invasive cardiac surgical procedures. The use of paravertebral blockade along with an anesthetic technique designed to facilitate rapid recovery allowed early extubation in the operating room or intensive care unit in all but one patient. Extubated patients leaving the operating room were comfortable. No postoperative respiratory complications occurred.