276. The technical and biological validation of an LH assay for use with the Western Grey Kangaroo (Macropus fuliginosis) and Black-flanked Rock Wallaby (Petrogale lateralis lateralis)

2008 ◽  
Vol 20 (9) ◽  
pp. 76
Author(s):  
P. Matson ◽  
C. Mayberry ◽  
N. Willers ◽  
M. A. Blackberry ◽  
G. B. Martin
Keyword(s):  
Plasma Concentrations ◽  
Standard Curve ◽  
Biological Validation ◽  
Grey Kangaroo ◽  
Coefficients Of Variation ◽  
Western Grey Kangaroo ◽  
Technical Validation ◽  
Zoo Biology ◽  
Smithsonian Institute ◽  
And Control

Methods for the measurement of marsupial LH invariably rely upon the similarity of the LH molecule between different species and usually use anti-ovine or anti-bovine LH antibody and an ovine or bovine labelled LH preparation. Initial attempts to measure plasma LH in the Western Grey Kangaroo with assays using antibodies to 4 different isoforms of ovine LH raised in 7 different rabbits were unsuccessful. An enzymeimmunoassay (EIA) developed for the Asian elephant (Zoo Biology 23:45–63) was then applied to the Western Grey Kangaroo and the Black-flanked Rock Wallaby. This EIA has an anti-bovine-LH monoclonal antibody (518B7 provided by Dr Jan Roser, University of California, Davis, USA), biotinylated ovine LH label and bovine LH standard (NIADDK-oLH-26 and NIH-bLH-B10, both provided by Dr Janine Brown and Nicole Abbondanza, Smithsonian Institute, Front Royal, Virginia USA). Technical validation showed that serial dilution down to 1:8 of plasma from 7 individuals of each species showed parallelism to the assay standard curve, and control samples (1.24–5.30 ng/mL) had between-assay coefficients of variation <9%. Biological validation was achieved by challenging animals with intramuscular GnRH (Fertagyl®, 2.5 µg/kg) and measuring LH before and 25 min after the injection. Significant increases in plasma concentrations of LH (mean ± sem; all P > 0.0005) were seen after GnRH for both the Western Grey Kangaroo (from 5.0 ± 0.8 ng/mL to 9.4 ± 1.2 ng/mL; n = 19) and the Black-flanked Rock Wallaby (from 6.0 ± 0.7 ng/mL to 10.6 ± 0.6 ng/mL; n = 28). In conclusion, this assay can be successfully used to measure LH in these two species.

The measurement of luteinising hormone in the western grey kangaroo (Macropus fuliginosus ocydromus) and the black-flanked rock wallaby (Petrogale lateralis lateralis)

2009 ◽  
Vol 31 (1) ◽  
pp. 61 ◽  
Author(s):  
Phillip Matson ◽  
Christopher Mayberry ◽  
Nicole Willers ◽  
Margaret A. Blackberry ◽  
Graeme B. Martin
Keyword(s):  
Enzyme Immunoassay ◽  
Luteinising Hormone ◽  
Standard Curve ◽  
Grey Kangaroo ◽  
Western Grey Kangaroo

An enzyme immunoassay with an anti-bovine-LH antibody (518B7) was applied to female western grey kanagaroos (Macropus fuliginosus ocydromus) and black-flanked rock wallabies (Petrogale lateralis lateralis). Validation showed parallelism to the assay standard curve, and significant increases in plasma LH concentrations after challenging animals with intramuscular GnRH.

A Sensitive and Facile Assay for the Measurement of Activated Protein C Activity Levels in Vivo

1993 ◽  
Vol 69 (05) ◽  
pp. 441-447 ◽  
Author(s):  
Carolyn L Orthner ◽  
Billy Kolen ◽  
William N Drohan
Keyword(s):  
Protein C ◽  
Plasma Concentrations ◽  
Limited Proteolysis ◽  
Activated Protein C ◽  
Microtiter Plate ◽  
Reversible Inhibitor ◽  
Activity Levels ◽  
Standard Curve ◽  
Agarose Beads

SummaryActivated protein C (APC) is a serine protease which plays an important role as a naturally occurring antithrombotic enzyme. APC, which is formed by thrombin-catalyzed limited proteolysis of the zymogen protein C, functions as an anticoagulant by proteolytic inactivation of the coagulation cofactors VIIIa and Va. APC is inhibited by several members of the serpin family as well a by α2-macroglobulin. APC is being developed as a therapeutic for the prevention and treatment of thrombosis. We have developed an assay to quantify circulating levels of enzymatically active APC during its administration to patients, in healthy individuals, and in various disease states. This assay utilizes an EDTA-dependent anti-protein C monoclonal antibody (Mab) 7D7B10 to capture both APC and protein C from plasma, prepared from blood collected in an anticoagulant supplemented with the reversible inhibitor p-aminobenzamidine. Mab 7D7B10-derivatized agarose beads are added to the wells of a 96-well filtration plate, equilibrated with Tris-buffered saline, and incubated for 10 min with 200 μl of plasma. After washing, APC and protein C are eluted from the immunosorbent beads with a calcium-containing buffer into the wells of a 96-well microtiter plate containing antithrombin III (ATIII) and heparin. The amidolytic activity of APC is then measured on a kinetic plate reader following the addition of L-pyroglutamyl-L-prolyl-L-arginine-p-nitroanilide (S-2366) substrate.The rate of substrate hydrolysis was proportional to APC concentration over a 200-fold concentration range (5.0 to 1,000 ng/ml) when measured continuously over a 15 to 30 min time period. The coefficient of variation was 5.9% at 35 ng/ml and 8.8% at 350 ng/ml APC. The sensitivity of the assay could be increased by measuring the amount of color produced after longer incubation times in the endpoint mode. The measured APC activity levels were little affected by varying protein C or prothrombin over the extremes of 0 to 150% of normal plasma concentrations. By constructing the standard curve in protein C-deficient plasma, the concentration of APC activity in normal pooled plasma was determined to be 2.8 ng/ml (45 pM), which represents 0.08% of the protein C concentration. The assay was approximately 50-fold more sensitive than the identical assay, but using Mab-coated microtiter wells rather than immunosorbent beads as the capture step.

Morphometric Registration of Cytotoxic Changes of Epithelial Cells In Vitro: A Methodological Study

1990 ◽  
Vol 17 (3) ◽  
pp. 174-176
Author(s):  
Lis Andersen ◽  
Dorthe Arenholt-Bindslev
Keyword(s):  
Culture System ◽  
Optimal Allocation ◽  
Volume Density ◽  
Cell Culture System ◽  
Allocation Of Resources ◽  
Methodological Study ◽  
Epithelial Cell Culture ◽  
Coefficients Of Variation ◽  
And Control

Quantification of toxicity-induced cytomorphological effects in an epithelial cell culture system is described. Estimates of volume density and star volume of mitochondria and lysosomes are given. Mean volumes (n = 5) and coefficients of variation of these parameters were equal in experimental (TPA-treatment) and control cultures. An optimal allocation of resources for estimating cytomorphometric parameters would be to increase the number of culture flasks.

scholarly journals Impact on Antibiotic Resistance, Therapeutic Success, and Control of Side Effects in Therapeutic Drug Monitoring (TDM) of Daptomycin: A Scoping Review

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 263
Author(s):  
Carolina Osorio ◽  
Laura Garzón ◽  
Diego Jaimes ◽  
Edwin Silva ◽  
Rosa-Helena Bustos
Keyword(s):  
Side Effects ◽  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Bacterial Resistance ◽  
Plasma Concentrations ◽  
Resistant Bacteria ◽  
Therapeutic Drug ◽  
Therapeutic Success ◽  
Favorable Clinical Outcome ◽  
And Control

Antimicrobial resistance (AR) is a problem that threatens the search for adequate safe and effective antibiotic therapy against multi-resistant bacteria like methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE) and Clostridium difficile, among others. Daptomycin is the treatment of choice for some infections caused by Gram-positive bacteria, indicated most of the time in patients with special clinical conditions where its high pharmacokinetic variability (PK) does not allow adequate plasma concentrations to be reached. The objective of this review is to describe the data available about the type of therapeutic drug monitoring (TDM) method used and described so far in hospitalized patients with daptomycin and to describe its impact on therapeutic success, suppression of bacterial resistance, and control of side effects. The need to create worldwide strategies for the appropriate use of antibiotics is clear, and one of these is the performance of therapeutic drug monitoring (TDM). TDM helps to achieve a dose adjustment and obtain a favorable clinical outcome for patients by measuring plasma concentrations of an administered drug, making a rational interpretation guided by a predefined concentration range, and, thus, adjusting dosages individually.

scholarly journals Effects of Dietary Supplementation with Different Polyunsaturated Fatty Acids on Expression of Genes Related to Somatotropic Axis Function in the Liver, Selected Blood Indicators, Milk Yield and Milk Fatty Acids Profile in Dairy Cows

2016 ◽  
Vol 16 (4) ◽  
pp. 1045-1058 ◽  
Author(s):  
Essa Dirandeh ◽  
Armin Towhidi ◽  
Zarbakht Ansari ◽  
Saeeid Zeinoaldini ◽  
Mehdi Ganjkhanlou
Keyword(s):  
Fatty Acids ◽  
Plasma Concentrations ◽  
Dietary Supplementation ◽  
Omega 3 ◽  
Milk Fatty Acids ◽  
Somatotropic Axis ◽  
Fatty Acids Profile ◽  
Expression Of Genes ◽  
Omega 6 ◽  
And Control

Abstract The objective of this study was to investigate whether dietary supplementation with different polyunsaturated fatty acids (PUFA s) affects expression of genes related to somatotropic axis and the plasma concentrations of insulin, glucose, non-esterified fatty acids (NEFA), beta hydroxyl butyrate acids (BHBA) and insulin-like growth factor 1 (IGF1) and milk fatty acids profile. Right after calving, Holstein cows (n=45) were randomly assigned to one of three diets supplemented with roasted whole soybean as a source of omega-6 PUFA (omega-6, n=15), linseed as a source of omega-3 PUFA (omega-3, n=15) or palm oil (control, n=15). Each cow was in the study over a period of 70 days. Blood samples were collected every two weeks from day 1 to 70 of lactation and plasma concentrations of insulin, glucose, NEFA, BHBA and IGF1 were determined. Liver samples were taken from a subset of 18 cows (6 per diet) at day 70 postpartum and hepatic mRNA level of total growth hormone-receptor 1A (GHR1A), insulin receptor (INSR), IGF1 and insulinlike growth factor binding protein (IGFBP2) was assessed. Experimental diets did not affect milk yield. Plasma glucose and insulin concentrations were greater for omega-3 treatment compared to omega-6 and control treatments. Cows fed diets enriched in omega-3 exhibited greater INSR and GHR1A mRNA expression, and a tendency for greater IGF1 mRNA expression in the liver compared to omega-6 and control cows. Plasma IGF1 concentration was significantly higher in omega-3 treatment compared with omega-6 and control treatments. Results of this study suggest that feeding omega-3 PUFA s during early postpartum couples with the somatotropic axis, leading to an increase in plasma IGF1 concentration in dairy cows.

Thyroid and parathyroid-independent increase in plasma 1,25-dihydroxyvitamin D during late pregnancy in the rat

1988 ◽  
Vol 116 (3) ◽  
pp. 381-385 ◽  
Author(s):  
T. M. Nguyen ◽  
A. Halhali ◽  
H. Guillozo ◽  
M. Garabedian ◽  
S. Balsan
Keyword(s):  
Vitamin D ◽  
Placental Transfer ◽  
Plasma Concentrations ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Vitamin D Metabolites ◽  
Pregnant Rats ◽  
Dihydroxyvitamin D ◽  
Fetal Plasma ◽  
And Control

ABSTRACT The effect of thyroparathyroidectomy (TPTX) on the plasma concentrations of the vitamin D metabolites (25-(OH)D, 24,25-(OH)2D and 1,25-(OH)2D) has been studied in pregnant rats and their fetuses during the last quarter of gestation. Maternal and fetal vitamin D metabolites were not significantly affected by TPTX. A significant increase in plasma 1,25-(OH)2D concentrations was observed in both TPTX and control mothers and fetuses from days 19 to 21. Fetal and maternal plasma 25-(OH)D were positively correlated in both control and TPTX groups. Such a correlation was also found for 24,25-(OH)2D in the two groups. In contrast, a positive correlation between maternal and fetal plasma concentrations of 1,25-(OH)2D was found in TPTX but not in control rats. These data suggest that major alterations in calcium metabolism, such as that produced by maternal TPTX, are insufficient to affect the changes in maternal and fetal plasma 1,25-(OH)2D during late pregnancy significantly. They also suggest that parathyroid hormone, thyroxine, and/or calcitonin may control a possible placental transfer of 1,25-(OH)2D in the rat. J. Endocr. (1988) 116, 381–385

Quantification of the Plasma Concentrations of Perampanel Using High-Performance Liquid Chromatography and Effects of the CYP3A4*1G Polymorphism in Japanese Patients

2020 ◽  
Vol 58 (10) ◽  
pp. 915-921
Author(s):  
Sho Ohkubo ◽  
Yumiko Akamine ◽  
Tadashi Ohkubo ◽  
Yuka Kikuchi ◽  
Masatomo Miura
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Clinical Practice ◽  
Plasma Volume ◽  
High Performance ◽  
Plasma Concentrations ◽  
Japanese Patients ◽  
Hplc Method ◽  
Limit Of Quantification ◽  
Coefficients Of Variation

Abstract Here, we developed a novel high-performance liquid chromatography (HPLC) method for quantification of perampanel in clinical practice and investigated the relationships between the plasma concentrations of perampanel obtained by this HPLC method and the CYP3A4*1G polymorphism. The developed HPLC method was validated based on US Food and Drug Administration. The developed HPLC method could be performed with a plasma volume of only 200 μL and had a limit of quantification (LOQ) of 2.5 ng/mL. The coefficients of variation (CVs) for intra- and inter-day assays were less than 10.4 and 7.2%, respectively, and the accuracy was &lt;2.4% for both assays. A total of 12 patients who received 2 mg perampanel had C0 values ranging from 70.5 to 451 ng/mL, and the CV showed a large variation of 51.4%. No correlations were observed between the dose-adjusted C0 and the CYP3A4*1G polymorphism. This method was superior to previously reported methods in terms of plasma volume and LOQ and was clinically applicable. Perampanel showed high variations in individual plasma concentrations; however, individual differences could not be predicted from analysis of the CYP3A4*1G polymorphism before perampanel administration. Therefore, after beginning perampanel treatment, the dose should be determined based on the observed plasma concentration.

Immunoradiometric assay with use of magnetizable particles: measurement of thyrotropin in blood spots, to screen for neonatal hypothyroidism.

1986 ◽  
Vol 32 (10) ◽  
pp. 1966-1968 ◽  
Author(s):  
K V Waite ◽  
G F Maberly ◽  
G Ma ◽  
C J Eastman
Keyword(s):  
Incubation Time ◽  
Separation Procedure ◽  
Immunoradiometric Assay ◽  
Assay Sensitivity ◽  
Neonatal Hypothyroidism ◽  
Blood Spots ◽  
Standard Curve ◽  
Coefficients Of Variation ◽  
Specialized Equipment ◽  
Short Incubation Time

Abstract We adapted a commercial immunoradiometric assay (IRMA) to measure thyrotropin in filter-paper blood spots. Two 3-mm blood spots are used for each standard and sample. These are incubated for 2 h with radiolabeled antibody and for 30 min with magnetic antibody, followed by a 10-min separation procedure. Assay sensitivity is 6 milli-int. units/L. Coefficients of variation (precision profile of the standard curve) ranged from 4.3 to 9.6%. The coefficient of correlation (r) between thyrotropin concentrations in the blood spots and in serum was 0.93. Pre-elution of the blood spots is necessary for short incubation time. Short incubation time, little need for specialized equipment, the high precision and sensitivity characteristic of IRMA, and ease of collection, transport, and storage of the blood-spot samples make this assay suitable for neonatal hypothyroid screening.

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