THE BIOLOGICAL DIFFERENTIATION OF 99Mo AND 99Tcm IN RABBITS AND ITS EFFECT ON THE GAMMA-COUNTING RATE OF PLASMA SAMPLES

1966 ◽  
Vol 44 (3) ◽  
pp. 363-370
Author(s):  
G. A. Robinson ◽  
A. McCarter
Keyword(s):  
Half Life ◽  
Counting Rate ◽  
Plasma Samples ◽  
Nuclear Decay ◽  
Gamma Energy ◽  
Blood Samples ◽  
Daughter Nuclide ◽  
Gamma Counting ◽  
Beta Emission ◽  
Biological Differentiation

Thirty-one rabbits were each injected intravenously with 250–450 μcuries molybdate-99Mo in transient equilibrium with 99Tcm. Blood samples were taken at intervals from 0.5 to 48 hours after the isotope injections. The gamma-counting rate of the blood plasma was recorded at 13 intervals during the 96 hours subsequent to the bleedings. Gamma curves, uncorrected for nuclear decay, were biphasic for 151 of the 194 samples. Recognizable first components (mean half-life ± s.e.m., 6.12 ± 0.10 hours). represented the buildup of 99Tcm to equilibrium levels in 53 samples (38 of these from rabbits fed on control diets) and decay of "excess" 99Tcm in 101 others (65 for rabbits fed on diets containing 0.4% Na2MoO4). The second components (mean half-life 65.9 ± 1.1 hours) represented a condition of transient equilibrium between 99Mo present in the samples at time of bleeding and the daughter nuclide. Biological differentiation of 99Mo and 99Tcm as observed in this study indicated that the indiscriminate measurement of gamma emissions for 99Mo-containing systems may give apparent 99Mo concentrations 0.57–2.31 times the actual values. Counting of either the total beta emission or a specific 99Mo gamma energy is recommended when the measurement of 99Mo is attempted.

Stability of antioxidant vitamins in whole human blood during overnight storage at 4°C and frozen storage up to 6 months

2018 ◽  
Vol 88 (3-4) ◽  
pp. 151-157 ◽  
Author(s):  
Scott W. Leonard ◽  
Gerd Bobe ◽  
Maret G. Traber
Keyword(s):  
Ascorbic Acid ◽  
Whole Blood ◽  
Healthy Subjects ◽  
Frozen Storage ◽  
Blood Collection ◽  
Plasma Samples ◽  
Optimal Conditions ◽  
Plasma Ascorbic Acid ◽  
Blood Samples ◽  
Sample Handling

Abstract. To determine optimal conditions for blood collection during clinical trials, where sample handling logistics might preclude prompt separation of erythrocytes from plasma, healthy subjects (n=8, 6 M/2F) were recruited and non-fasting blood samples were collected into tubes containing different anticoagulants (ethylenediaminetetra-acetic acid (EDTA), Li-heparin or Na-heparin). We hypothesized that heparin, but not EDTA, would effectively protect plasma tocopherols, ascorbic acid, and vitamin E catabolites (α- and γ-CEHC) from oxidative damage. To test this hypothesis, one set of tubes was processed immediately and plasma samples were stored at −80°C, while the other set was stored at 4°C and processed the following morning (~30 hours) and analyzed, or the samples were analyzed after 6 months of storage. Plasma ascorbic acid, as measured using HPLC with electrochemical detection (LC-ECD) decreased by 75% with overnight storage using EDTA as an anticoagulant, but was unchanged when heparin was used. Neither time prior to processing, nor anticoagulant, had any significant effects upon plasma α- or γ-tocopherols or α- or γ-CEHC concentrations. α- and γ-tocopherol concentrations remained unchanged after 6 months of storage at −80°C, when measured using either LC-ECD or LC/mass spectrometry. Thus, refrigeration of whole blood at 4°C overnight does not change plasma α- or γ-tocopherol concentrations or their catabolites. Ascorbic acid is unstable in whole blood when EDTA is used as an anticoagulant, but when whole blood is collected with heparin, it can be stored overnight and subsequently processed.

scholarly journals Feasibility of Extrapolating Randomly Taken Plasma Samples to Trough Levels for Therapeutic Drug Monitoring Purposes of Small Molecule Kinase Inhibitors

2021 ◽  
Vol 14 (2) ◽  
pp. 119
Author(s):  
Ruben A. G. van Eerden ◽  
Esther Oomen-de Hoop ◽  
Aad Noordam ◽  
Ron H. J. Mathijssen ◽  
Stijn L. W. Koolen
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Small Molecule ◽  
Trough Concentration ◽  
Drug Monitoring ◽  
Half Life ◽  
Kinase Inhibitors ◽  
Therapeutic Drug ◽  
Blood Samples ◽  
Elimination Half ◽  
Trough Levels

Small molecule kinase inhibitors (SMKIs) are widely used in oncology. Therapeutic drug monitoring (TDM) for SMKIs could reduce underexposure or overexposure. However, logistical issues such as timing of blood withdrawals hamper its implementation into clinical practice. Extrapolating a random concentration to a trough concentration using the elimination half-life could be a simple and easy way to overcome this problem. In our study plasma concentrations observed during 24 h blood sampling were used for extrapolation to trough levels. The objective was to demonstrate that extrapolation of randomly taken blood samples will lead to equivalent estimated trough samples compared to measured Cmin values. In total 2241 blood samples were analyzed. The estimated Ctrough levels of afatinib and sunitinib fulfilled the equivalence criteria if the samples were drawn after Tmax. The calculated Ctrough levels of erlotinib, imatinib and sorafenib met the equivalence criteria if they were taken, respectively, 12 h, 3 h and 10 h after drug intake. For regorafenib extrapolation was not feasible. In conclusion, extrapolation of randomly taken drug concentrations to a trough concentration using the mean elimination half-life is feasible for multiple SMKIs. Therefore, this simple method could positively contribute to the implementation of TDM in oncology.

Half-lives of spherical proton emitters within the framework of fractional calculus

2014 ◽  
Vol 23 (09) ◽  
pp. 1450044 ◽  
Author(s):  
Abdullah Engin Çalik ◽  
Hüseyin Şirin ◽  
Hüseyin Ertik ◽  
Buket Öder ◽  
Mürsel Şen
Keyword(s):  
Fractional Calculus ◽  
Fractional Derivative ◽  
Nuclear Structure ◽  
Caputo Fractional Derivative ◽  
Half Life ◽  
Nuclear Decay ◽  
Life Values ◽  
Derivative Order

In this paper, the half-life values of spherical proton emitters such as Sb , Tm , Lu , Ta , Re , Ir , Au , Tl and Bi have been calculated within the framework of fractional calculus. Nuclear decay equation, related to this phenomenon, has been resolved by using Caputo fractional derivative. The order of fractional derivative μ being considered is 0 < μ ≤ 1, and characterizes the fractality of time. Half-life values have been calculated equivalent with empirical ones. The dependence of fractional derivative order μ on the nuclear structure has also been investigated.

Search for Melanoma Markers in Plasma and Serum Samples

2005 ◽  
Vol 11 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Roberta Seraglia ◽  
Susanna Vogliardi ◽  
Graziella Allegri ◽  
Stefano Comai ◽  
Mario Lise ◽  
...  
Keyword(s):  
High Frequency ◽  
Healthy Subjects ◽  
Ionic Species ◽  
Low Molecular Weight ◽  
Ionization Mass ◽  
Plasma Samples ◽  
Serum Samples ◽  
Blood Samples ◽  
Melanoma Patients ◽  
Diagnostic Ions

Fourteen blood samples from patients with melanomas and 11 blood samples from healthy subjects were analyzed by matrix-assisted laser desorption/ionization mass spectrometry. The study focussed on species of low molecular weight, in the 800–5000 Da range, present in plasma and sera. While for healthy subjects plasma samples lead to the production of a higher number of ionic species, for melanoma patients a high number of diagnostic ions, present with high frequency and with quite high relative abundance, are present, in particular, in serum samples and, to a lesser extent, also in plasma. Since plasma samples are obtained more easily in comparison to sera, it is possible to suggest that plasma can also be used for these studies.

Determination of tissue plasminogen activator and its "fast" inhibitor in plasma.

1986 ◽  
Vol 32 (3) ◽  
pp. 482-485 ◽  
Author(s):  
J Chmielewska ◽  
B Wiman
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Plasma Samples ◽  
Inhibitor Concentration ◽  
Blood Samples ◽  
Analytical Recovery ◽  
Specific Determination ◽  
Tissue Plasminogen ◽  
Coupled Assay

Abstract We describe efficient, accurate methods for specific determination of tissue plasminogen activator (t-PA, EC 3.4.21.31) and its "fast" inhibitor in plasma. In this coupled assay, a sample containing t-PA is incubated with plasminogen, a plasmin (EC 3.4.21.7) substrate of low Km and high Kcat, and fibrin as a stimulator. The inhibitor of t-PA is determined by incubating the sample with a known amount of t-PA in excess, then determining the residual t-PA. Both t-PA and t-PA inhibitor can be determined in many samples simultaneously within a few hours. These assays are modifications of procedures described by us (Clin Chim Acta 1983;127:279-88 and Thromb Res 1983;31:427-36). Their accuracy as assessed by analytical recovery of pure t-PA added to blood samples (91 +/- 4%) or of partly purified inhibitor added to plasma samples (102 +/- 10%) is satisfactory, as is their precision. For the t-PA assay the CV was 1.6% (within run) or 4.1% (between run). The corresponding values for the inhibitor assay were 4.5% (within run) or 8.4% (between run) if the inhibitor concentration exceeded 3 arb. units/mL.

Effect of Endotoxin on Kinetics of Antithrombin III

1979 ◽  
Author(s):  
H. Tanaka ◽  
N. Kobayashi ◽  
T. Takeuchi ◽  
M. Takada ◽  
T. Haekawa
Keyword(s):  
Half Life ◽  
Antithrombin Iii ◽  
Coagulation Factors ◽  
Synthesis Rate ◽  
Blood Samples ◽  
At Iii ◽  
Kinetics Of ◽  
Plasma Half Life

The kinetics of antithrombin III(AT III) in dogs were studied using I-125-labelled AT III and Se-75-methionine. As reported at the last meeting of ISH, the plasma half-life of AT III was 1.7±0.2 days in normal 5 control dogs. The double i.v. administration of 200 ug/ltg of endotoxin and the single i.v. administration of 1 mg/kg of endotoxin resulted in 30% decrease of plasma AT III, 60% decrease of coagulation Factors (I, II, V, VII, VIII, IX), the shortening of plasma half-life of AT III to 1.4 days and the increase of J3u values, suggesting increase of the synthesis rate of AT III. Then, the synthesis of AT III was studied directly using Se-75-methionine. After i.v. injection of Se-75-methionine, blood samples were obtained. One ml of sample plasma was incubated for 24 hrs with 1 ml of anti-AT III antiserum, which was produied in rabbits and the radioactivity of the precipitates were determined. About 80% of AT III was recovered in the precipitates by this method. The maximum radioactivity was obtained 18 hrs after injection of Se-75-methionine, and 0.27 % of total injected Se-75-methionine were utilized to the production of AT III.These results indicates that; 1. Endotoxin accelerates the metabolism of AT III. 2. The analysis of AT III production is possible using Se-75-methionine as a tracer.

What Determines Primary Breast Cancer Patients' Hope to Recover

1998 ◽  
Vol 82 (3) ◽  
pp. 835-840
Author(s):  
Bert De Brabander ◽  
Pol Gerits ◽  
Robert Sacré ◽  
Jan Lamote
Keyword(s):  
Breast Cancer ◽  
Central Nervous System ◽  
Real Life ◽  
Plasma Samples ◽  
Breast Cancer Patients ◽  
Main Metabolite ◽  
Blood Samples ◽  
The Central Nervous System ◽  
Life Stressor ◽  
Na Depletion

The main purpose was to offer evidence for the hypothesis that the stronger an acute real life stressor, namely, hearing from the physician that one has breast cancer and that one has to undergo mastectomy, the greater the induced noradrenaline (NA) depletion in the central nervous system (CNS) and the more the pa-dent loses hope to recover. The data were derived from answers to interviews, questionnaires, and analyses of blood samples obtained from the patients on the day of admission to the hospital for a biopsy and 24 hours after the surgeon communicated the results of the biopsy to the patients. Analysis showed that a decline in 3-Methoxy 4-Hydroxy Methoxy 4-Hydroxy Phenylethylene Glycol (MHPG) concentration in blood plasma samples after being informed of the diagnosis is associated with less hope of recovery. MHPG is the main metabolite of CNS noradrenaline.

scholarly journals Quality Control of Serum and Plasma by Quantification of (4E,14Z)-Sphingadienine-C18-1-Phosphate Uncovers Common Preanalytical Errors During Handling of Whole Blood

2018 ◽  
Vol 64 (5) ◽  
pp. 810-819 ◽  
Author(s):  
Xinyu Liu ◽  
Miriam Hoene ◽  
Peiyuan Yin ◽  
Louise Fritsche ◽  
Peter Plomgaard ◽  
...  
Keyword(s):  
Whole Blood ◽  
Plasma Samples ◽  
Blood Samples ◽  
Disease States ◽  
Long Term Storage ◽  
Reliable Assessment ◽  
Therapeutic Decisions ◽  
Life Threatening ◽  
Research Findings

Abstract BACKGROUND Nonadherence to standard operating procedures (SOPs) during handling and processing of whole blood is one of the most frequent causes affecting the quality of serum and plasma. Yet, the quality of blood samples is of the utmost importance for reliable, conclusive research findings, valid diagnostics, and appropriate therapeutic decisions. METHODS UHPLC-MS-driven nontargeted metabolomics was applied to identify biomarkers that reflected time to processing of blood samples, and a targeted UHPLC-MS analysis was used to quantify and validate these biomarkers. RESULTS We found that (4E,14Z)-sphingadienine-C18-1-phosphate (S1P-d18:2) was suitable for the reliable assessment of the pronounced changes in the quality of serum and plasma caused by errors in the phase between collection and centrifugation of whole blood samples. We rigorously validated S1P-d18:2, which included the use of practicality tests on &gt;1400 randomly selected serum and plasma samples that were originally collected during single- and multicenter trials and then stored in 11 biobanks in 3 countries. Neither life-threatening disease states nor strenuous metabolic challenges (i.e., high-intensity exercise) affected the concentration of S1P-d18:2. Cutoff values for sample assessment were defined (plasma, ≤0.085 μg/mL; serum, ≤0.154 μg/mL). CONCLUSIONS Unbiased valid monitoring to check for adherence to SOP-dictated time for processing to plasma or serum and/or time to storage of whole blood at 4 °C is now feasible. This novel quality assessment step could enable scientists to uncover common preanalytical errors, allowing for identification of serum and plasma samples that should be excluded from certain investigations. It should also allow control of samples before long-term storage in biobanks.

scholarly journals University of Kiel Radiocarbon Measurements VII

Radiocarbon ◽  
1973 ◽  
Vol 15 (1) ◽  
pp. 113-126 ◽  
Author(s):  
H. Erlenkeuser ◽  
H. Willkomm
Keyword(s):  
Oxalic Acid ◽  
Half Life ◽  
Counting Rate ◽  
Background Sample ◽  
Organic Fractions ◽  
Modern Standard

This list contains data obtained during 1971. Unless otherwise stated, all organic samples or organic fractions are carefully washed with dil. HCl and dil. NaOH to remove all carbonates. Age calculations are based on 95% of NBS oxalic acid standard activity with modern value A.D. 1950. Results are calculated using the Libby half-life and are given in the B.P. scale. Also ages of shells are calculated with the NBS oxalic acid standard. Ages are not corrected for δC13 variations. Errors correspond to Iσ variation of sample net counting rate including statistics of modern standard and background. Sample activities, if given in per cent refer to 0.95 NBS oxalic acid standard activity.

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