Fluorimetric Determination of Creatine

1960 ◽  
Vol 6 (6) ◽  
pp. 537-548 ◽  
Author(s):  
Rex B Conn
Keyword(s):  
Alkaline Solution ◽  
Normal Adult ◽  
Adult Males ◽  
Fluorimetric Determination ◽  
Fluorimetric Method ◽  
Fluorescent Products ◽  
Colorimetric Methods

Abstract A new fluorimetric method for determining creatine in serum, blood, and urine is described. The method is based upon the coupling of guanidine compounds with ninhydrin in alkaline solution to produce highly fluorescent products. In degree of sensitivity and simplicity the method possesses several advantages over currently used colorimetric methods, and creatine can be determined in concentrations as low as 1.0 X 10-7M. The serum creatine concentration was found to be 0.41 mg.% in normal adult males, who excrete only small amounts of creatine in the urine.

scholarly journals Determination of the Normal Range of Serum LH and FSH Levels in Normal Adult Males

1990 ◽  
Vol 66 (5) ◽  
pp. 572-583 ◽  
Author(s):  
Yoshiaki KUMAMOTO ◽  
Naoki ITOH ◽  
Hiroshi MARUTA ◽  
Yoshio TAKAGI ◽  
Naoto MIKUMA ◽  
...  
Keyword(s):  
Normal Adult ◽  
Adult Males ◽  
Normal Range ◽  
Serum Lh

scholarly journals Stability-Indicating Photochemical Method for the Assay of Riboflavin: Lumichrome Method

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Iqbal Ahmad ◽  
Syed Haider Abbas ◽  
Zubair Anwar ◽  
Muhammad Ali Sheraz ◽  
Sofia Ahmed ◽  
...  
Keyword(s):  
Light Intensity ◽  
Alkaline Solution ◽  
Fluorescence Emission ◽  
Spectrometric Method ◽  
Fluorimetric Method ◽  
Stability Indicating ◽  
Photochemical Conversion ◽  
Photochemical Method ◽  
Two Component

A stability-indicating photochemical method for the assay of riboflavin (RF) in photodegraded samples and aged vitamin preparations has been developed. It is based on photochemical conversion of RF to lumichrome (LC) in alkaline solution under controlled conditions of light intensity, temperature, pH, time of exposure, and distance. Under these conditions about two-thirds of RF is converted to LC and on the basis of the RF : LC ratio the concentration of RF can be determined in degraded solutions. The method involves the extraction of photolyzed solutions of RF (pH 2.0) with chloroform and determination of LC along with lumiflavin (LF) by a two-component spectrometric method at 356 and 445 nm. The method has been validated and the results of the assay of RF in photodegraded solutions compare well with those of the standard USP fluorimetric method. The recovery of the method is 99–101% and the precision is within 2%. The method is stability-indicating and can be applied to the assay of RF in photodegraded solutions and aged vitamin preparations. The method is specific compared to that of the USP fluorimetric method in which the degraded LC may interfere with the fluorescence emission of RF.

FLUORIMETRIC DETERMINATION OF FREE PLASMA 11-HYDROXYCORTICOSTEROIDS IN MAN

1960 ◽  
Vol XXXIII (II) ◽  
pp. 297-307 ◽  
Author(s):  
Pieter De Moor ◽  
Omer Steeno ◽  
Monique Raskin ◽  
Achiel Hendrikx
Keyword(s):  
Human Plasma ◽  
Screening Test ◽  
Plasma Cholesterol ◽  
Adrenocortical Function ◽  
Plasma Samples ◽  
Fluorimetric Determination ◽  
Background Fluorescence ◽  
Fluorimetric Method ◽  
Free Plasma

ABSTRACT A fluorimetric method for the determination of the free 11-hydroxycorticosteroids (cortisol and corticosterone) in human plasma has been described. Using a routine fluorimeter, 1–2 ml plasma samples are needed for a valid determination. The procedure is reliable as judged by the criteria of Borth (1957). One single trained technician can perform 40–50 determinations a day. Background fluorescence equivalent to about 3 μg % hydrocortisone is found; this background fluorescence does not appear to be related to plasma cholesterol. The method is designed primarily to study the dynamics of adrenocortical function in a given individual and can be of help as an emergency screening test (a determination can be done in one hour) in cases of suspected adrenocortical dysfunction.

Fluorimetric Method for the Determination of Cortisol in Small Quantities of Salmonid Plasma

1968 ◽  
Vol 25 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Edward M. Donaldson ◽  
Ulf H. Fagerlund ◽  
Peter J. Schmidt
Keyword(s):  
Fluorimetric Determination ◽  
Fluorimetric Method ◽  
Low Cortisol ◽  
Validation Experiments

A method is described for the fluorimetric determination of cortisol in 1-ml aliquots of salmonid plasma. Validation experiments are presented which indicate that the reliability of the method is satisfactory. The method provides the means for the determination of low cortisol concentrations, such as those encountered in hypophysectomized or resting salmonids (0.01–0.05 μg/ml).

scholarly journals Significant Population Variation in Adult Male Height Associated with the Y Chromosome and the Aromatase Gene

2001 ◽  
Vol 86 (9) ◽  
pp. 4147-4150 ◽  
Author(s):  
Justine A. Ellis ◽  
Margaret Stebbing ◽  
Stephen B. Harrap
Keyword(s):  
Confidence Interval ◽  
Y Chromosome ◽  
Adult Height ◽  
Large Population ◽  
Population Sample ◽  
Population Variation ◽  
Normal Adult ◽  
Adult Males ◽  
Gene Encoding

The determination of human adult height is dependent on both environmental and genetic factors. Rare causes of abnormal stature have been identified, including mutations in the gene encoding aromatase (CYP19) and regions on the Y chromosome. However, the possible role of these loci in the genetic control of normal adult height is unknown. We have performed an association study using common biallelic polymorphisms within CYP19 and the Y chromosome to determine whether these loci are associated with variation in height in 413 adult males and 335 females drawn at random from a large population sample. An association between CYP19 and height was found (difference, 2.0 cm; 95% confidence interval, 0.16–3.8; P = 0.003), but this was more evident in men (difference, 2.3 cm; 95% confidence interval, 0.38–4.4; P = 0.05) than women (difference, 0.2 cm; 95% confidence interval, −2.1 to 1.6; P = 0.94). An association was also found with the Y chromosome (P = 0.009; difference of 1.9 cm; 95% confidence interval, 0.5–3.4). Additionally, when men were grouped according to haplotypes of the CYP19 and Y chromosome polymorphisms, a difference of 4.2 cm (95% confidence interval, 0.67–7.3) was detected (P = 0.004). These results suggest that in men, genetic variation in CYP19 and on the Y chromosome are involved in determining normal adult height, and that these loci may interact in an additive fashion.

scholarly journals A fluorimetric method for the determination of tryptophan in animal tissues

1974 ◽  
Vol 139 (3) ◽  
pp. 625-631 ◽  
Author(s):  
M. K. Gaitonde
Keyword(s):  
Rat Brain ◽  
Maximum Intensity ◽  
Fluorescent Product ◽  
Animal Tissues ◽  
Fluorimetric Method ◽  
Tissue Extracts ◽  
Naturally Occurring ◽  
Fluorescent Products ◽  
Ninhydrin Reagent

Tryptophan, tryptamine and peptides containing N-terminal tryptophan give two highly fluorescent products on treatment with dithiothreitol and acid ninhydrin reagent 1 or 2. The first fluorescent product (product A) gives an emission at 500nm on activation at 390–400nm and is stable for 20min. The second product (product B), which gives an emission at 530nm on activation at 470nm, is detectable within 1h after the reaction. It gives almost maximum intensity in 4h and is stable for at least 48h. Except lysine, which in equimolar amounts gives less than 1% of a product similar to product B, no other naturally occurring amino compounds give fluorescent products. A procedure is given for the determination of 0.05–34nmol of tryptophan in tissue extracts. By using this procedure rat brain was found to contain 17.56±0.76 (s.e.m.) nmol/g wet wt.

Characterization of Tamm-Horsfall Urinary Glycoprotein

1973 ◽  
Vol 31 ◽  
pp. 420-421
Author(s):  
John P. Robinson ◽  
J. David Puett
Keyword(s):  
Electron Microscopy ◽  
Circular Dichroism ◽  
Secondary Structure ◽  
Quaternary Structure ◽  
Normal Adult ◽  
Morphological Properties ◽  
Adult Males ◽  
Circular Dichroïsm ◽  
Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

HAPTEN-RADIOIMMUNOASSAY OF PLASMA OESTRADIOL

1973 ◽  
Vol 72 (2) ◽  
pp. 330-344 ◽  
Author(s):  
Peter Doerr
Keyword(s):  
Adult Male ◽  
Normal Values ◽  
Normal Adult ◽  
Adult Males ◽  
Reagent Blank ◽  
Keyhole Limpet Haemocyanin ◽  
Ether Extraction ◽  
The Mean ◽  
Assay Precision ◽  
Plasma Oestradiol

ABSTRACT A hapten-radioimmunoassay for plasma oestradiol is described and information about the reliability of the method is given in detail. Oestradiol-3-hemisuccinate coupled to keyhole limpet haemocyanin is used for immunization of rabbits. The antiserum utilized for the assay is characterized by its titer, affinity and specificity. Following ether extraction and NaOH-light petroleum partition oestradiol is separated from crossreacting oestrogens by TLC. Oxidation of oestradiol on the plate is prevented by mercaptoethanol. To separate free and antibody bound ligand 250 μg dextran-coated charcoal per tube is used in the presence of bovine serum gammaglobulin (1 mg/ml). The between-assay precision based on 15 different determinations of control samples from normal adult male plasma was 9.4% (C. V.). The mean reagent blank value of 31 determinations was equivalent to 0.3 pg oestradiol and the detection limit in terms of the 99% confidence limit for a single blank value, was equivalent to 4.3 pg oestradiol. A procedure for detecting plasma blanks is described. Plasma oestradiol is separated from approximately all concomitant substances originally present in the sample by enzymatic conversion into oestrone and a second TLC. No plasma blanks could be detected with respect to normal adult male plasma. Normal values for adult males based on 51 subjects were characterized by a median of 17.2 pg/ml and the 95 percentiles of 9.5–27.6.

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