Threshold pixel size for shape determination of microcalcifications in digital mammography: a pilot study

2005 ◽  
Vol 114 (1-3) ◽  
pp. 415-423 ◽  
Author(s):  
M. Ruschin ◽  
B. Hemdal ◽  
I. Andersson ◽  
S. Börjesson ◽  
M. Håkansson ◽  
...  
Keyword(s):  
Pilot Study ◽  
Digital Mammography ◽  
Pixel Size ◽  
Shape Determination

Studies on the Fibrinolytic System in Human Plasma: Quantitative Determination of Plasminogen Activators and Proactivators

1979 ◽  
Vol 41 (02) ◽  
pp. 365-383 ◽  
Author(s):  
C Kluft
Keyword(s):  
Pilot Study ◽  
Plasma Level ◽  
Human Plasma ◽  
Plasminogen Activators ◽  
Venous Occlusion ◽  
Quantitative Information ◽  
Optimal Recovery ◽  
Dextran Sulphate ◽  
Baseline Levels

SummaryEffects due to plasma plasminogen activators and proactivators are usually studied in assay systems where inhibitors influence the activity and where the degree of activation of proactivators is unknown. Quantitative information on activator and proactivator levels in plasma is therefore not availableStudies on the precipitating and activating properties of dextran sulphate in euglobulin fractionation presented in this paper resulted in the preparation of a fraction in which there was optimal recovery and optimal activation of a number of plasminogen activators and proactivators from human plasma. The quantitative assay of these activators on plasminogen-rich fibrin plates required the addition of flufenamate to eliminate inhibitors. The response on the fibrin plates (lysed zones) could be coverted to arbitrary blood activator units (BAU). Consequently, a new activator assay which enables one to quantitatively determine the plasma level of plasminogen activators and proactivators together is introduced.Two different contributions could be distinguished: an activity originating from extrinsic activator and one originating from intrinsic proactivators. The former could be assayed separately by means of its resistance to inhibition by Cl-inactivator. Considering the relative concentrations of extrinsic and intrinsic activators, an impression of the pattern of activator content in plasma was gained. In morning plasma with baseline levels of fibrinolysis, the amount of extrinsic activator was negligible as compared to the level of potentially active intrinsic activators. Consequently, the new assay nearly exclusively determines the level of intrinsic activators in morning plasma. A pilot study gave a fairly stable level of 100 ± 15 BAU/ml (n = 50). When fibrinolysis was stimulated by venous occlusion (15 min), the amount of extrinsic activator was greatly increased, reaching a total activator level of 249 ± 27 BAU/ml (n = 7).

scholarly journals Effects of Delayed Sample Processing on Determination of Total and High Molecular Weight (HMW) Adiponectin in Serum and Plasma: A Pilot Study

2016 ◽  
Vol 8 (3) ◽  
pp. 19
Author(s):  
Choaping Ng ◽  
Felicity J Rose ◽  
Sahar Keshvari ◽  
Marina M Reeves ◽  
Goce Dimeski ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Pilot Study ◽  
High Molecular Weight ◽  
Accurate Determination ◽  
Mean Difference ◽  
Serum Samples ◽  
Blood Samples ◽  
Hmw Adiponectin ◽  
Total Adiponectin

<p>Adiponectin is a beneficial adipocyte-secreted hormone, which circulates in a variety of multimeric forms termed low and high molecular weight (LMW/HMW). Effectiveness of clinical therapeutic trials which target adiponectin rely on accurate determination of circulating total and HMW adiponectin levels but the accuracy may be influenced by variations in sample handling processes. The aim of this pilot study was to investigate the effects of delayed processing of blood samples on the concentration of total and HMW adiponectin.</p><p>Materials and Methods: Fasting blood samples were collected for analysis of total and HMW adiponectin concentrations in EDTA plasma and serum from eight healthy participants.  Samples were centrifuged post 15 min storage at 4<sup>o</sup>C as the comparative ‘ideal’ method or after up to 72 h of refrigerated storage or 6 h at room temperature. Total and HMW adiponectin concentrations were measured by ELISA.</p><p>Results: Under ideal handling conditions measurements of total and HMW adiponectin concentrations were significantly higher in serum than in plasma (mean difference: -1.3 µg/mL [95% CI: -1.6, -1.0], p&lt;0.001; and, -0.6 µg/mL [95% CI: -0.7, -0.5], p&lt;0.001, respectively).  Storage of blood samples at 4<sup>o</sup>C for 72 h resulted in significant reductions in concentration of total adiponectin in serum (mean difference: -1.4 µg/mL [95% CI: -2.0, -0.8], p=0.001) and HMW adiponectin in plasma (mean difference: -0.6 µg/mL [95%CI: -0.9, -0.2], p=0.007), compared with ideal conditions.  Further analysis of serum samples showed a significant decrease in total adiponectin concentration after 6 h storage at 4<sup>o</sup>C (mean difference: -1.4 µg/mL [95% CI: -2.0, -0.8], p=0.001) compared with ideal conditions.</p><p>Conclusions: Delayed processing of samples may have differential effects on the concentration of total and HMW adiponectin in serum or plasma. Larger studies are warranted for clinical intervention trials.</p>

scholarly journals Shape determination of unidimensional objects: the virtual image correlation method

2010 ◽  
Vol 6 ◽  
pp. 10004
Author(s):  
M. Francois ◽  
B. Semin ◽  
H. Auradou ◽  
J. Vatteville
Keyword(s):  
Correlation Method ◽  
Image Correlation ◽  
Virtual Image ◽  
Shape Determination

Determination of cannabinoids in oral fluid and urine of “light cannabis” consumers: a pilot study

2018 ◽  
Vol 57 (2) ◽  
pp. 238-243 ◽  
Author(s):  
Roberta Pacifici ◽  
Simona Pichini ◽  
Manuela Pellegrini ◽  
Roberta Tittarelli ◽  
Flaminia Pantano ◽  
...  
Keyword(s):  
Pilot Study ◽  
Oral Fluid ◽  
Urine Samples ◽  
Screening Tests ◽  
Gas Chromatography Mass Spectrometry ◽  
Negative Results ◽  
A Value ◽  
Order Of Magnitude ◽  
Confirmation Analysis

Abstract Background In those countries where cannabis use is still illegal, some manufacturers started producing and selling “light cannabis”: dried flowering tops containing the psychoactive principle Δ-9-tetrahydrocannabinol (THC) at concentrations lower than 0.2% together with variable concentration of cannabidiol (CBD). We here report a pilot study on the determination of cannabinoids in the oral fluid and urine of six individuals after smoking 1 g of “light cannabis”. Methods On site screening for oral fluid samples was performed, as a laboratory immunoassay test for urine samples. A validated gas chromatography-mass spectrometry (GC-MS) method was then applied to quantify THC and CBD, independently from results of screening tests. Results On site screening for oral fluid samples, with a THC cut-off of 25 ng/mL gave negative results for all the individuals at different times after smoking. Similarly, negative results for urine samples screening from all the individuals were obtained. Confirmation analyses showed that oral fluid THC was in the concentration range from 2.5 to 21.5 ng/mL in the first 30 min after smoking and then values slowly decreased. CBD values were usually one order of magnitude higher than those of THC. THC-COOH, the principal urinary THC metabolite, presented the maximum urinary value of 1.8 ng/mL, while urinary CBD had a value of 15.1 ng/mL. Conclusions Consumers of a single 1 g dose of “light cannabis” did not result as positive in urine screening, assessing recent consumption, so that confirmation would not be required. Conversely, they might result as positive to oral fluid testing with some on-site kits, with THC cut-off lower than 25 ng/mL, at least in the first hour after smoking and hence confirmation analysis can be then required. No conclusions can be drawn of eventual chronic users.

A novel determination of energy expenditure efficiency during a balance task using accelerometers. A pilot study

2017 ◽  
Vol 31 (2) ◽  
pp. 61-67
Author(s):  
Alejandro Caña-Pino ◽  
Maria Dolores Apolo-Arenas ◽  
Javier Moral-Blanco ◽  
Ernesto De la Cruz-Sánchez ◽  
Luis Espejo-Antúnez
Keyword(s):  
Pilot Study ◽  
Energy Expenditure ◽  
Balance Task
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