Luminescent probes for detergent solutions. A simple procedure for determination of the mean aggregation number of micelles

Abstract Recent reports have suggested that determination of glycosylated hemoglobin may serve as a clinical aid for long-term blood glucose control in diabetes mellitus. We describe a simple procedure for measuring it by ion-exchange chromatography. Hemolysates were subjected to Bio-Rex 70 chromatographic separation on small columns. Percentages in the normal group ranged from 4.7 to 8.8% of total hemoglobin; the mean +/- standard error was 6.61 +/- 0.31%. Values in the diabetic group ranged from 6.9 to 17.4%; the mean was 10.83 +/- 0.34. Plasma glucose concentrations after fasting, plotted vs. the percent of glycosylated hemoglobin, revealed a linear relationship at normal or moderately high glucose concentrations. However, the values for glycosylated hemolgobin approached a plateau with grossly higher plasma glucose concentrations after fasting. Our results support the view that, due to its long half-life, the estimation of glycoylated hemoglobin reflects the integrated glucose concentrations to which the erythrocytes have been previously exposed.

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Detection of Circulating Tissue Factor and Factor VII in a Normal Population

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650365 ◽

1996 ◽

Vol 75 (05) ◽

pp. 772-777 ◽

Cited By ~ 30

Author(s):

Sybille Albrecht ◽

Matthias Kotzsch ◽

Gabriele Siegert ◽

Thomas Luther ◽

Heinz Großmann ◽

...

Keyword(s):

Tissue Factor ◽

Normal Population ◽

Mean Value ◽

Factor Vii ◽

Significant Difference ◽

Age Dependent ◽

The Mean ◽

Highly Correlated ◽

And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

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Determination of Plasminogen in Clots and Thrombi

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655625 ◽

1966 ◽

Vol 16 (01/02) ◽

pp. 038-050 ◽

Cited By ~ 6

Author(s):

Ulla Hedner ◽

Inga Marie Nilsson ◽

B Robertson

Keyword(s):

Mean Value ◽

Main Mechanism ◽

Clot Lysis ◽

Post Mortem ◽

Digestion Time ◽

Normal Volunteers ◽

Casein Solution ◽

The Mean

SummaryThe plasminogen content was determined by a casein method in plasma and serum from 20 normal volunteers. The mean plasminogen content was found to be 10.1 ACU (the arbitrary caseinolytic unit defined in such a way that using a 3% casein solution and a digestion time of 20 min. at 37°C, 10 ACU gave an extinction of 0.300). No difference between serum and plasma regarding the plasminogen content was found.Plasminogen was determined in drained and drained plus washed clots prepared from 2 ml plasma. The highest values found in the drained clots were 0.9 ACU/clot and 0.2 ACU/clot in the drained plus washed clots.Plasminogen was also determined in drained and drained plus washed clots prepared from plasma with added purified plasminogen. The plasminogen was recovered in the washing fluid. According to these tests, then, purified added plasminogen is washed out of the clots.The plasminogen content of 20 thrombi obtained post mortem was also determined. The mean value was found to be 0.7 ACU/cm thrombus. Judging from our results, the “intrinsic clot lysis theory” is not the main mechanism of clot dissolution.

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SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

Acta Endocrinologica ◽

10.1530/acta.0.0720714 ◽

1973 ◽

Vol 72 (4) ◽

pp. 714-726 ◽

Cited By ~ 3

Author(s):

A. Burger ◽

B. Miller ◽

C. Sakoloff ◽

M. B. Vallotton

Keyword(s):

Ionic Strength ◽

Limit Of Detection ◽

Improved Method ◽

Accuracy Of Measurement ◽

Tracer Amount ◽

The Mean ◽

Physiological Values ◽

Hyperthyroid Patients ◽

Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

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Determination of the Probability Distribution of the Mean Sound Level

Archives of Acoustics ◽

10.2478/v10168-010-0041-1 ◽

2010 ◽

Vol 35 (4) ◽

pp. 543-550 ◽

Cited By ~ 4

Author(s):

Wojciech Batko ◽

Bartosz Przysucha

Keyword(s):

Probability Distribution ◽

Probability Distribution Function ◽

Mean Value ◽

Sound Level ◽

Function Form ◽

Noise Levels ◽

Logarithmic Mean ◽

The Mean ◽

Estimation Of Uncertainty

AbstractAssessment of several noise indicators are determined by the logarithmic mean <img src="/fulltext-image.asp?format=htmlnonpaginated&src=P42524002G141TV8_html\05_paper.gif" alt=""/>, from the sum of independent random resultsL1;L2; : : : ;Lnof the sound level, being under testing. The estimation of uncertainty of such averaging requires knowledge of probability distribution of the function form of their calculations. The developed solution, leading to the recurrent determination of the probability distribution function for the estimation of the mean value of noise levels and its variance, is shown in this paper.

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Direct Determination of the Mean Nitrogen Concentration in Connection with Nitrogen Washout with Multiple Breath Method

Scandinavian Journal of Clinical and Laboratory Investigation ◽

10.3109/00365516409060524 ◽

1964 ◽

Vol 16 (3) ◽

pp. 332-338 ◽

Cited By ~ 3

Author(s):

T. Lundman ◽

E. Orinius ◽

I. Ståhle

Keyword(s):

Nitrogen Concentration ◽

Direct Determination ◽

Nitrogen Washout ◽

The Mean

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Simultaneous Determination of Alogliptin, Linagliptin, Saxagliptin, and Sitagliptin in Bulk Drug and Formulation by UPLC Q-TOF-MS

Current Pharmaceutical Analysis ◽

10.2174/1573412915666190708162012 ◽

2020 ◽

Vol 17 (1) ◽

pp. 95-105

Author(s):

Ramji Rathod ◽

Faraat Ali ◽

Amrish Chandra ◽

Robin Kumar ◽

Meenakshi Dahiya ◽

...

Keyword(s):

Internal Standard ◽

Gradient Elution ◽

Ultra Performance Liquid Chromatography ◽

Pharmaceutical Dosage Forms ◽

Sensitivity And Selectivity ◽

The Mean ◽

Bulk Drug ◽

Positive Ion ◽

Higher Sensitivity

Background: A simple and sensitive Ultra Performance Liquid Chromatography-Mass Spectrometry method was developed and validated to measure the concentrations of Alogliptin (ALO), Linagliptin (LIN), Saxagliptin (SAX), and Sitagliptin (SIT) using Pioglitazone (PIO) as an internal standard. Methods: Chromatographic separation of six gliptins was achieved on a C-18 column (100×2.1 mm, 2.7 μm) using a mobile phase consisting of formic acid in water, 0.1%v/v: acetonitrile in gradient elution. Electrospray ionization (ESI) source was operated in the positive ion mode. Targeted MS/MS mode on a QTOF MS was used to quantify the drug utilizing the transitions of 340.1(m/z), 473.2 (m/z), 316.2 (m/z), 408.1 (m/z), and 357.1 (m/z) for ALO, LIN, SAX, SIT and PIO respectively. Results: As per ICH Q2R1 guidelines, a detailed validation of the method was carried out and the standard curves were found to be linear over the concentration ranges of 1516.0-4548.1 ng mL-1, 519.8- 1559.4 ng mL-1, 1531.4-4594.3 ng mL-1and 1519.6-4558.8 ng mL-1 for ALO, LIN, SAX and SIT respectively. Precision and accuracy results were within the acceptable limits. The mean recovery was found to be 98.8 _ 0.76 % (GEM), 102.2 _ 1.59 % (LIN), 95.3 _ 2.74 % (SAX) and 99.2 _ 1.75 % (SIT) respectively. Conclusions: The optimized validated UPLC QTOF-MS/MS method offered the advantage of shorter analytical times and higher sensitivity and selectivity. The optimized method is suitable for application in quantitative analysis of pharmaceutical dosage forms for QC laboratory.

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