Rapid radioisotopic procedure for determination of nortriptyline in plasma.

1976 ◽  
Vol 22 (6) ◽  
pp. 761-764 ◽  
Author(s):  
K P Maguire ◽  
G D Burrows ◽  
J P Coghlan ◽  
B A Scoggins

Abstract With the widespread use of tricyclic antidepressant drugs, the relationship between the concentration of the drug in the plasma and the therapeutic response is of considerable interest. We describe a double-isotope derivative dilution procedure for measuring plasma nortriptyline. In the method, [14C]nortriptyline is used for estimating procedural losses and [3H]acetic anhydride for derivative formation. The assay is rapid and adequately specific, sensitive, precies, and reproducible for routine clinical use. We used it to investigate the variation in steady-state drug concentrations in plasma of persons who were on a 150 mg/day dose of nortriptyline. Intra-individual variation from day to day was 10-14%. This variation was not significantly affected by the dosage schedule, the time of sampling after an oral dose, or the storage of the plasma samples. For 19 patients on 150 mg of nortriptyline per day, the mean concentration in plasma was 181 +/- 22 (SE) mug/liter, a value that compares well with our previous findings and those of other groups.

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Leila Shafie Bafti ◽  
Maryam Alsadat Hashemipour ◽  
Hamidreza Poureslami ◽  
Zeinab Hoseinian

The aim of the present study was to evaluate the relationship between BMI and tooth decay in a population of Iranian children. In this cross-sectional descriptive/analytical study, 1482 children were selected from kindergartens and preschool centers in Kerman, Iran. The children underwent examination of deciduous teeth (using the dmft index) after determination of height and weight for calculation of BMI. The relationship between BMI (after adjustment for age) and dmft was determined using Poisson’s regression model. The mean of dmft in children with normal BMI was 1.5-fold that in subjects with extra body weight. Age had a significant effect on dmft. In addition, dmft was higher in boys compared to girls. The results of the present study showed that caries rate in the deciduous teeth of 3–6-year-old children decreases with an increase in body weight.


1966 ◽  
Vol 12 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Wendell T Caraway ◽  
Herman Marable

Abstract A colorimetric carbonate procedure for the determination of uric acid has been modified to include incubation of serum with uricase to destroy uric acid. Residual nonurate chromogens are subtracted from total chromogens to obtain the concentration of "true" uric acid. Result obtained by the carbonate and the uricase-carbonate methods were in good agreement. The mean concentration of nonurate chromogens in serum is approximately 2% of the true uric acid values. Recovery of uric acid added to serum is essentially quantitative. Formaldehyde markedly inhibits uricase activity and interferes with recoveries. The uricase-carbonate method is applicable to hemolytic serum and to serums from patients with uremia or those receiving high doses of salicylate in which excess concentrations of nonurate chromogens may be encountered.


2018 ◽  
Vol 7 (1) ◽  
pp. 31
Author(s):  
Holiday Robley ◽  
Michael E. Barnes

Digital color values were collected from the eggs of 128 spawns from individual landlocked fall Chinook salmon Oncorhynchus tshawytscha females from Lake Oahe, South Dakota, USA, in 2008, 2009, 2015 and 2016. For all spawns, the mean (SE) a* value, a measure of red-green chromaticness, was 10.99 (0.27), and ranged from 3.98 to 18.71. Mean (SE) b* (yellow-green) was 20.27 (0.32), and ranged from 9.28 to 28.50. Mean (SE) L* (white-black) was 20.73 (0.48), and ranged from 3.98 to 18.71. Egg total color index also showed considerable variation, with a mean (SE) of 23.05 (0.37) and range from 11.70 to 31.64. Egg survival to the eyed-stage was weakly, but significantly, correlated to b* (r = 0.206), L* (r = 0.185), Chroma (r = 0.211), and Entire Color Index (r = 0.211). Spawns with no egg survival had eggs with significantly lower a* values compared to spawns where at least some of the eggs survived to the eyed stage. L*, a*, b*, Chroma, and Entire Color Index varied significantly among the years, but Hue and egg survival to the eyed stage did not. The results of this study indicate a possible link between egg color and landlocked fall Chinook salmon egg survival, possibly due to differences in the diets of feral broodstock females or their ability to deposit bodily carotenoids in the developing eggs.


2010 ◽  
Vol 93 (5) ◽  
pp. 1462-1467 ◽  
Author(s):  
Megha Sharma ◽  
Pragya Nautiyal ◽  
Surendra Jain ◽  
Deepti Jain

Abstract Combination therapy with acyclovir and zidovudine is used for the treatment of herpes-infected immunocompromised patients. In the view of the optimal drug concentrations (minimum effective concentrations) for viral suppression and avoidance of drug toxicity, monitoring of drug levels has been considered essential to determine drug concentrations in plasma after administration of a dose of acyclovir and zidovudine. A simple, precise, and rapid RP-HPLC method has been developed for this purpose. Chromatographic separation was performed using methanolwater (50 + 50, v/v), pH 2.5 adjusted with orthophosphoric acid, as an isocratic mobile phase at a flow rate of 0.8 mL/min with an Inertsil ODS (C18) column (5 µm particle size, 250 ⨯ 4.60 mm id). Detection was carried out using a UV photo diode array detector at 258 nm. The plasma samples were prepared by a protein precipitation method. The retention time for acyclovir and zidovudine was 3.5 ± 0.2 and 6.2 ± 0.3 min, respectively. The method was linear in the range of 2001800 and 4003600 ng/mL with LOQ of 200 ng (SD = ±1.4) and 400 ng (SD = ±0.9) for zidovudine and acyclovir, respectively, in plasma. The mean accuracy was 98.0 and 96.4, with average extraction recovery of 64.8 ± 2.1 and 77.5 ± 1.7 for lower nominal concentrations of acyclovir and zidovudine, respectively.


1970 ◽  
Vol 53 (3) ◽  
pp. 539-542
Author(s):  
R W Henningson

Abstract A 1968 North American authentic milk sample survey determined that the mean freezing point value of milk is –0.5404°C. Statistical concepts permit the calculation of a value, –0.525°C, 2.326 standard deviations from a mean with 95% confidence that 99% of all subsequent observations will be below the value. Based on this survey, it was recommended that the Interpretation of the freezing point value of milk be made a part of the official final action thermistor cryoscopic method for the determination of the freezing point value of milk, and include the following: an upper limit for the freezing point value of milk, an official definition of an authentic milk sample, and a logical procedure for the confirmation of added water. A copy of the report and an explanatory letter were sent to approximately 100 North American regulatory agencies. Reports were received from 49 regulatory agencies with 39 favoring the recommendations, 6 opposing the recommendations, and 4 having no opinion. It is recommended that the Interpretation of the freezing point of milk be included in both the thermistor cryoscopic and the Hortvet methods.


1982 ◽  
Vol 28 (3) ◽  
pp. 457-461 ◽  
Author(s):  
P K Sonsalla ◽  
T A Jennison ◽  
B S Finkle

Abstract A quantitative "high-pressure" liquid-chromatographic assay for tricyclic antidepressant drugs in plasma or serum is described in which amitriptyline, nortriptyline, imipramine, desipramine, doxepin, and desmethyldoxepin are separated with a 10-micrometer particle size silica column and a methanol/NH4OH/NH4NO3 solvent system. The drugs and two internal standards are extracted with hexane/isoamyl alcohol, the solvent layer is evaporated at 40 degrees C, and the drugs are detected at 254 nm. Drug concentrations are linear with absorbance from 25 to 1000 micrograms/L; within-assay and between-assay CVs are less than or equal to 10%.


1993 ◽  
Vol 71 (5) ◽  
pp. 769-770
Author(s):  
K. Soliman ◽  
L. Zikovsky ◽  
C. Dallaire

The concentration of Al, P, and Si in 142 samples of five fruit juices, measured with neutron activation analysis and atomic absorption spectroscopy, varies from 0 to 1.44, 31 to 201, and 1.5 to 35 µg/mL, respectively. The mean concentration of Al in apple, grape, grapefruit, orange, and pineapple juices is 0.54, 0.94, 0.24, 0.29, and 0.62 µg/mL, respectively. The mean concentration of P in the same juices is 102, 115, 124, 127, and 76 µg/mL. The storage of juice in aluminized containers with internal plastic coating does not increase the concentration of Al in the juice.


1963 ◽  
Vol 26 (1) ◽  
pp. 65-73 ◽  
Author(s):  
M. G. BRUSH

SUMMARY Plasma levels of progesterone and 20 α-hydroxypregn-4-en-3-one have been studied after intravenous (i.v.) and intramuscular (i.m.) injections of progesterone in sheep. I.v. injected progesterone was removed from the bloodstream very rapidly and it was necessary to give 50 mg. before it was possible to detect progesterone at times up to 10 min. after the injection. With 100 mg. amounts of progesterone injected i.v. the mean concentration in samples taken up to 10 min. after the injection was 34·7 μg./100 ml. plasma (range 4–110 μg./100 ml. in 9 samples), but after 1 hr. the mean level was 2·2 μg./100 ml. plasma (range 0–10 μg./100 ml. in 10 samples). The concentrations of 20 α-hydroxypregn-4-en-3-one were usually, but not always, less than those of progesterone. When progesterone was given by i.m. injection it was not possible to establish detectable blood levels. The effect of the injection vehicle was also studied for each injection route. Some new modifications of Short's method (1958) for the determination of plasma progesterone are described and discussed.


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