Glucocorticoids directly affect spectrophotometry of bilirubin in amniotic fluid.

1984 ◽  
Vol 30 (5) ◽  
pp. 677-680
Author(s):  
A Milwidsky ◽  
S Yagel ◽  
M Chaouat ◽  
M Mayer
Keyword(s):  
Amniotic Fluid ◽  
Binding Sites ◽  
Time Dependent ◽  
Hemolytic Disease ◽  
Low Concentrations ◽  
Chemical Determination ◽  
Cautious Interpretation ◽  
Layer Chromatography

Abstract Dexamethasone or prednisolone, added in vitro to bilirubin-containing amniotic fluid, produces a time-dependent decrease in the 450-nm absorbance of the pigment. Neither the chemical determination of bilirubin in amniotic fluid nor the lecithin/sphingomyelin ratio as determined by thin-layer chromatography is affected by these glucocorticoids. The effect probably is not a result of displacement of bilirubin from its binding sites on albumin, because the absorbance of a solution of crystalline bilirubin at 450 nm is unaffected by added bovine serum albumin. Light scattering of amniotic fluid increases slightly when dexamethasone is added, whether or not low concentrations of bilirubin (less than 1.6 mumol/L) are present. Thus the effect on absorbance evidently is not ascribable to supersaturation and formation of a colloidal sol of bilirubin particles. This direct interference of glucocorticoids with the spectrophotometry of bilirubin in amniotic fluid prompts cautious interpretation of such data as an index to the severity of hemolytic disease of the fetus, specifically in cases of Rhesus-isoimmunization that are being treated with glucocorticoids.

scholarly journals Validation by isoelectric focusing of the anion-exchange isotransferrin fractionation step involved in determination of carbohydrate-deficient transferrin by the CDTect assay

1998 ◽  
Vol 44 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Torsten Arndt ◽  
Rolf Hackler ◽  
Tilman O Kleine ◽  
Axel M Gressner
Keyword(s):  
Isoelectric Focusing ◽  
Laboratory Diagnosis ◽  
Good Precision ◽  
Chronic Alcohol Abuse ◽  
Negative Results ◽  
Iron Saturation ◽  
Low Concentrations ◽  
Carbohydrate Deficient Transferrin

Abstract Serum concentration of carbohydrate-deficient transferrin (CDT) is used for laboratory diagnosis of chronic alcohol abuse. Using isoelectric focusing for validation of the initial isotransferrin fractionation step involved in the determination of CDT by the CDTect assay, we found a complete in vitro iron saturation of transferrin and sufficient stability of the transferrin iron load during column passage; effective separation of non-CDT-isotransferrins and CDT-isotransferrins at the microcolumns; partial coelution of trisialo-Fe2-transferrin, which did not significantly affect CDT measurement; partial retention of CDT-isotransferrins, especially disialo-Fe2-transferrin, which may cause falsely negative results for CDT at the upper reference limits; good precision of the isotransferrin fractionation step; and no significant effects of low concentrations of serum protein and transferrin. We strongly urge standardization of CDT analysis and suggest isoelectric focusing for validation of CDT analysis methods and verification of odd results.

Densitometry of phosphatidylcholine and sphingomyelin in high-density lipoproteins.

1983 ◽  
Vol 29 (7) ◽  
pp. 1435-1437 ◽  
Author(s):  
G Schmitz ◽  
H U Jabs ◽  
G Assmann
Keyword(s):  
Sulfuric Acid ◽  
Phosphotungstic Acid ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Concentrations ◽  
Layer Chromatography ◽  
Inexpensive Technique ◽  
Native Plasma ◽  
Enzymatic Methods

Abstract We describe the quantitative densitometric determination of phosphatidylcholine (PC) and sphingomyelin (SP) in human serum after precipitation with phosphotungstic acid/MgCl2 and use of thin-layer chromatography. After development, chromatographic plates were charred with methanolic sulfuric acid and MnCl2 and scanned by direct reflectance densitometry in an automated densitometric system interfaced to a basic programmable computing integrator. The method is sensitive enough to detect abnormally low concentrations of PC and SP in high-density lipoproteins. The accuracy of the method was tested either with the Bartlett phosphorus assay or with enzymatic methods for PC and SP; correlations of the described method with the enzymatic determinations were r = 0.93 and 0.88, respectively. Day-to-day precision (CV) for the phospholipid determination was 8.6% for PC and 12.2% for SP. The major advantage of this inexpensive technique is that native plasma or serum or the serum supernate after precipitation can be used without prior delipidation. With this technique serum high-density lipoproteins had PC values of 1.08 (SD 0.32) mmol/L in men (n = 158) and 1.12 (SD 0.37) mmol/L in women (n = 192); similarly, SP values were 0.23 (SD 0.07) mmol/L in the men and 0.23 (SD 0.08) mmol/L in the women. The differences by sex are not significant.

AN ACCURATE METHOD FOR THE ESTIMATION OF LOW CONCENTRATIONS OF DEXTRAN IN PLASMA

1957 ◽  
Vol 35 (6) ◽  
pp. 383-390 ◽  
Author(s):  
Robert E. Semple
Keyword(s):  
Aqueous Extract ◽  
Accurate Method ◽  
Protein Precipitation ◽  
In Vitro Tests ◽  
Plasma Samples ◽  
Carbohydrate Concentration ◽  
Low Concentrations ◽  
Standard Deviations

A method is presented for the determination in plasma of small (50–150 mg./100 ml.) amounts of dextran. The procedure, which requires between 3 and 4 hours, consists of protein precipitation, glucose removal by dialysis, and the determination of the carbohydrate concentration of the resulting aqueous extract by a modified anthrone technique. Results of in vitro tests show that average dextran recovery is essentially 100% and that standard deviations in recovery range from 1.7 to 2.5% depending upon the dextran concentration. Deviations are reduced to a range of 1.4–1.7% by the use of duplicate plasma samples.

Radial "high-performance" thin-layer chromatography used to assess fetal lung maturity

1990 ◽  
Vol 36 (5) ◽  
pp. 728-731 ◽  
Author(s):  
J R Mackenzie ◽  
M Truesdale
Keyword(s):  
Thin Layer ◽  
Amniotic Fluid ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Fetal Lung ◽  
Additional Method ◽  
Layer Chromatography ◽  
Hptlc Method ◽  
Lung Maturity

Abstract A radial "high-performance" thin-layer chromatographic (HPTLC) method is described by which the percentages and ratios of phosphatidylinositol, sphingomyelin, lecithin, phosphatidylethanolamine, phosphatidylglycerol, and dimethyl phosphatidylethanolamine may be determined simultaneously. An additional method for radial HPTLC determination of saturated phosphatidylcholine is described. We report results of application of these methods to greater than 2000 specimens of amniotic fluid from both diabetic and nondiabetic cases.

Effect of reticulocytosis on lactate dehydrogenase isoenzyme distribution in serum: in vivo and in vitro studies

1990 ◽  
Vol 36 (9) ◽  
pp. 1638-1641 ◽  
Author(s):  
S C Kazmierczak ◽  
W J Castellani ◽  
F Van Lente ◽  
E D Hodges ◽  
B Udis
Keyword(s):  
Flow Cytometry ◽  
Lactate Dehydrogenase ◽  
Cell Types ◽  
In Vitro Studies ◽  
Hemolytic Disease ◽  
Dehydrogenase Isoenzyme ◽  
Disease Analysis

Abstract We investigated the effect of reticulocytosis on the lactate dehydrogenase (LD; EC 1.1.1.27) isoenzyme LD1/LD2 ratio in patients with and without evidence of hemolytic disease. Analysis of sera from patients with reticulocytosis and in vivo hemolysis showed a mean LD1/LD2 ratio of 0.92 compared with a ratio of 0.69 in patients with in vivo hemolysis and normal reticulocyte counts. Determination of LD isoenzymes in erythrocyte lysate revealed significantly increased LD1/LD2 ratios for patients with marked reticulocytosis compared with those for patients with normal-to-minimal increases in reticulocytes. Finally, separation of mature erythrocytes and reticulocytes by flow cytometry revealed marked differences in the LD1/LD2 isoenzyme distribution between these two cell types. The ability of hemolysis to cause a "flipped" LD1/LD2 ratio is dependent on the proportion of the hemolyzed cells that are reticulocytes.

Simple, Rapid Determination of Lecithin and Sphingomyelin in Amniotic Fluid

1973 ◽  
Vol 19 (12) ◽  
pp. 1394-1396 ◽  
Author(s):  
K G Blass ◽  
R J Thibert ◽  
T F Draisey
Keyword(s):  
Sulfuric Acid ◽  
Amniotic Fluid ◽  
Rapid Determination ◽  
Standard Addition ◽  
Standard Curve ◽  
Sample Application ◽  
Instant Thin Layer Chromatography ◽  
Rhodamine B Dye ◽  
Layer Chromatography

Abstract We describe a rapid and very sensitive modified determination of lecithin and sphingomyelin in amniotic fluid. It requires 1.5 ml of amniotic fluid and can be done in less than 40 min. Modifications include "Instant Thin Layer Chromatography" plates (Gelman) with a punched disc system of sample application, as well as elimination of the acetone wash steps, and substitution of Rhodamine B dye for the corrosive sulfuric acid char technique of detection. The procedure can be quantified, and exact concentrations of lecithin in amniotic fluid can be determined by a standard addition procedure, or from a standard curve.

Vasodilation and glomerular binding of adrenomedullin in rabbit kidney are not CGRP receptor mediated

1997 ◽  
Vol 273 (2) ◽  
pp. R716-R724 ◽  
Author(s):  
H. Hjelmqvist ◽  
R. Keil ◽  
M. Mathai ◽  
T. Hubschle ◽  
R. Gerstberger
Keyword(s):  
Binding Sites ◽  
Membrane Receptors ◽  
Rabbit Kidney ◽  
Calcitonin Gene ◽  
Body Fluid Homeostasis ◽  
Mild Reduction ◽  
Specific Membrane ◽  
Camp Formation

The polypeptide adrenomedullin (ADM) was infused systemically to conscious rabbits to elucidate its actions on overall circulation and especially the renovascular bed and the formation and/or release of hormones important for body fluid homeostasis, including adrenocortical steroids. ADM lowered mean arterial pressure from 71.5 +/- 3.2 to 64.7 +/- 3.2 mmHg only at the highest dose of 25 pmol.min-1.kg-1 infused intravenously for 20 min and concomitantly induced tachycardia, possibly due to both baroreflex activation and direct cardiostimulatory effects. Renal blood flow (RBF) determined in rabbits chronically equipped with a perivascular ultrasonic flow probe increased from 55.4 +/- 2.1 to 67.4 +/- 2.7 and from 58.2 +/- 3.5 to 75.2 +/- 6.0 ml/min at ADM infusions of 5 and 25 pmol.min-1.kg-1, respectively. The elevation in RBF persisted even in the presence of the calcitonin gene-related peptide (CGRP1 receptor antagonist CGRP-(8-37). Of all osmoregulatory hormones tested, only corticosterone (Cort) plasma concentration increased in response to the highest ADM dose from 17.6 +/- 3.1 to 38.9 +/- 6.2 ng/ml, probably due to haroreflex activation. Subdepressor doses of ADM, however, caused a mild reduction in circulating Cort. Expression of functional high-affinity binding sites specific for ADM in vitro could be demonstrated for the renal artery and outer cortical glomeruli using 125I-labeled rat ADM as radioligand and determination of cellular adenosine 3',5'-cyclic monophosphate (cAMP) formation within the glomeruli. The ineffectiveness of CGRP-(8-37) to displace radiolabeled ADM from its binding sites, to inhibit ADM-induced glomerular cAMP formation, and to prevent ADM-induced renal vasodilation supports the hypothesis of ADM altering renal hemodynamics by interacting with ADM- and not CGRP-specific membrane receptors.

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