The Potential of Phosphorescence Spectrometry in Clinical Chemistry—The New Generation of Instrumentation and Methodology

1975 ◽  
Vol 21 (3) ◽  
pp. 285-299 ◽  
Author(s):  
C M O'Donnell ◽  
J D Winefordner

Abstract We review recent advances in instrumentation and methodology in phosphorimetry that should facilitate the use of phosphorimetry for clinical analyses and recent phosphorescence studies of interest to the clinical chemist. We indicate recent advances, particularly improvements in instrumentation, novel methodologies, and new chemical processes that result in either an increase in sensitivity or selectivity (or both) of measurement of compounds of clinical importance. The greatest use of phosphorimetry in the clinical laboratory will not be for the analysis of very large numbers of samples for one species via automatic instrumentation, but rather will be for the analysis of those molecular species difficult or impossible to measure by conventional methods (colorimetry, fluorometry, etc.). Although various instrumental and methodological advances are discussed separately here, the most important use of these advances in clinical chemistry will undoubtedly be when two or more of them are combined, for example, in the use of time- or frequency-resolved phosphorimetry for the selective measurement of the phosphorescence resulting with inorganic probes and the appropriate choice of solvent and pH (of course, the instrument could contain an image vidicon detector for rapid determination of the spectrum, the decay curve, or both).

1999 ◽  
Vol 37 (6) ◽  
pp. 1771-1776 ◽  
Author(s):  
H. Ceri ◽  
M. E. Olson ◽  
C. Stremick ◽  
R. R. Read ◽  
D. Morck ◽  
...  

Determination of the MIC, based on the activities of antibiotics against planktonic bacteria, is the standard assay for antibiotic susceptibility testing. Adherent bacterial populations (biofilms) present with an innate lack of antibiotic susceptibility not seen in the same bacteria grown as planktonic populations. The Calgary Biofilm Device (CBD) is described as a new technology for the rapid and reproducible assay of biofilm susceptibilities to antibiotics. The CBD produces 96 equivalent biofilms for the assay of antibiotic susceptibilities by the standard 96-well technology. Biofilm formation was followed by quantitative microbiology and scanning electron microscopy. Susceptibility to a standard group of antibiotics was determined for National Committee for Clinical Laboratory Standards (NCCLS) reference strains: Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, andStaphylococcus aureus ATCC 29213. Growth curves demonstrated that biofilms of a predetermined size could be formed on the CBD at specific time points and, furthermore, that no significant difference (P > 0.1) was seen between biofilms formed on each of the 96 pegs. The antibiotic susceptibilities for planktonic populations obtained by the NCCLS method or from the CBD were similar. Minimal biofilm eradication concentrations, derived by using the CBD, demonstrated that for biofilms of the same organisms, 100 to 1,000 times the concentration of a certain antibiotic were often required for the antibiotic to be effective, while other antibiotics were found to be effective at the MICs. The CBD offers a new technology for the rational selection of antibiotics effective against microbial biofilms and for the screening of new effective antibiotic compounds.


1970 ◽  
Vol 16 (2) ◽  
pp. 107-110 ◽  
Author(s):  
M A Evenson ◽  
P Jones ◽  
B Darcey

Abstract The need for simultaneous determination of the concentration of diphenylhydantoin (Dilantin) and primidone (Mysoline) in serum is frequently expressed to the clinical chemistry laboratory. Isothermal gas-liquid chromatography (GLC) has been used to develop a rapid, specific method. The method involves a single extraction and no derivative formation. The procedure is simple enough to be used with large numbers of samples. Detection limits for the method are 0.3 µg diphenylhydantoin per ml and 0.1 µg primidone per ml. The mean precision of the method is 6.2% and 4.8%, expressed as the coefficient of variation, for diphenylhydantoin and primidone, respectively. Barbiturates and glutethimide added to serum samples did not interfere with the analysis. The method has been used for more than 500 patients without interferences from metabolites, and meets all criteria for routine and emergency use.


1971 ◽  
Vol 17 (8) ◽  
pp. 715-720 ◽  
Author(s):  
Thomas O Tiffany ◽  
George F Johnson ◽  
Max E Chilcote

Abstract The GeMSAEC fast analyzer provides the clinical chemistry laboratory with an analytical instrument that can be used to perform large numbers of kinetic enzyme analyses. Precise enzyme-rate analyses can be done routinely, on a large scale, and at a decreased cost per test. Improved precision in analyses of enzymes should provide more reliable data because analytical variation is lessened. We have asked how the fast analyzer might provide more useful diagnostic information to the clinician. We have selected the ratio of SGOT to SGPT activity in serum as an example, and examined instrumental precision. The coefficients of variation of the ratio, determined in the range of 50 and 140 Karmen units (which represents slightly elevated to clearly elevated values), are 4.8% and 2.2%, respectively. We examined the feasibility of measuring two or more enzyme activities simultaneously in one sample, to produce a diagnostic enzyme profile. Determination of SGOT, SGPT, and GLDH in parallel is presented as an example. In addition, we illustrate spectrophotometric linearity at 340 nm and discuss instrumental noise and an experimental approach to determining it by use of a premix experiment.


2005 ◽  
Vol 43 (10) ◽  
pp. 5003-5008 ◽  
Author(s):  
G.-C. Lee ◽  
D.-G. Lee ◽  
S.-M. Choi ◽  
J.-H. Yoo ◽  
S.-H. Park ◽  
...  

2014 ◽  
Vol 12 (1) ◽  
pp. 65-76
Author(s):  
Ivana Rasic-Misic ◽  
Emilija Pecev-Marinkovic

Lead is one of the most studied clinically important metals due its high toxicity and a high number of workers exposed to it. The interest toward Pb is elevated by the fact that children are especially susceptible to lead poisoning. Research regarding lead poisoning requires a complex, multi-disciplinary (clinical medical and clinical chemical) approach. Monitoring human exposure to lead (intake, i.e. poisoning) may be achieved by quantification of Pb in tissues and body fluids. For that reason, a number of accurate and reliable analytical methods for the determination of Pb (analytical/preanalytical variable) were developed. An objective of this review paper is to provide key information necessary for proper interpretation of results of lead related clinical/laboratory tests.


1997 ◽  
Vol 41 (7) ◽  
pp. 1537-1540 ◽  
Author(s):  
F Peyron ◽  
A Favel ◽  
H Guiraud-Dauriac ◽  
M El Mzibri ◽  
C Chastin ◽  
...  

A rapid-flow cytofluorometric susceptibility test for in vitro amphotericin B testing of yeasts was evaluated and compared to the National Committee for Clinical Laboratory Standards (NCCLS) M27-T reference broth macrodilution method. The flow cytofluorometric method is based on the detection of decreased green fluorescence intensity of cells stained with DiOC5(3), a membrane potential-sensitive cationic dye, after drug treatment. Testing was performed on 134 clinical isolates (Candida spp. and Torulopsis glabrata). From the dose-response curve obtained for each isolate, three endpoints were calculated by computer analysis (the concentrations at which the fluorescence intensity was reduced by 50, 80, and 90%, i.e., 50% inhibitory concentration [IC50], IC80, and IC90, respectively). A regression analysis correlating these endpoints with the M27-T MICs showed that the best agreement was obtained with IC80. The flow cytofluorometric method showed good reproducibility with control strains. These initial results suggest that the flow cytofluorometric method is a valid alternative to the NCCLS reference method.


1958 ◽  
Vol 4 (2) ◽  
pp. 127-141 ◽  
Author(s):  
Abraham Saifer ◽  
Shirley Gerstenfeld ◽  
Michael C Zymaris

Abstract A rapid, semiautomatic system of microchemical analysis for the clinical chemistry laboratory has been proposed. Five basic elements of this system are: (1) The use of siliconated-heparinized plasma. (2) The use of the calibrated-pipet-tip buret technic for measuring small (0.10-ml.) samples. (3) The use of the decantation principle as a precision step in making quantitative transfers. (4) The use of automatic syringe pipets for adding constant volumes of reagents, (5) The use of specific enzymatic methods, whenever these are applicable, for the determination of biologic constituents. The analytic system has already been applied to the determination of such important biologic constituents as glucose, urea nitrogen, phosphorus, acid and alkaline phosphatases, sodium and potassium, calcium, and total protein. The semiautomatic system permits the use of microprocedures in a clinical chemistry laboratory by persons of limited technical skill.


1960 ◽  
Vol 38 (3) ◽  
pp. 475-478 ◽  
Author(s):  
P. Harris

The number of R. buoliana per shoot is a good index of its abundance in a pine stand; but the determination of the index at low population levels involves counting large numbers of shoots. However, for the conspicuous third instar larvae and older stages it can be determined rapidly by counting the number of individuals present on a tree and estimating the number of shoots by measuring the stem diameter and referring to a predetermined shoot-diameter curve for the stand.


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