Improvements in and clinical utility of a continuous-flow method for routine measurement of dialyzable (ultrafiltrable) calcium.

1979 ◽  
Vol 25 (11) ◽  
pp. 1939-1943 ◽  
Author(s):  
J Toffaletti ◽  
G N Bowers
Keyword(s):  
Continuous Flow ◽  
Clinical Utility ◽  
Clinical Laboratory ◽  
Serum Samples ◽  
The Past ◽  
Baseline Noise ◽  
Routine Service ◽  
Routine Measurement ◽  
Routine Clinical Laboratory ◽  
Continuous Flow Method

Abstract We describe modifications to the original continuous-flow procedure for dialyzable calcium (Clin. Chem. 23: 1258, 1977) needed to make the method more suitable for routine clinical laboratory use. The modifications simplify the continuous-flow (AutoAnalyzer) manifold, decrease baseline noise, increase the sensitivity, and permit use of a less-expensive fluorometer. Bias due to variation in serum processing is minimized by use of serum samples minimally exposed to air and a pH 7.40 buffer in place of the routinely processed sera and pH 7.30 buffer used formerly. Day-to-day precision (CV) during the past year for samples that included three different lots of quality-control sera was 2 to 3%. The analysis requires 200 micro L of serum, collected with minor additional precautions. We find that dialyzable calcium can be dependably measured in the routine service laboratory and show how this information is clinically more useful than is information on total calcium in serum.

scholarly journals Quantification of Serum Proteins Using Capillary Electrophoresis

1995 ◽  
Vol 32 (5) ◽  
pp. 493-497 ◽  
Author(s):  
M A Jenkins ◽  
M D Guerin
Keyword(s):  
Capillary Electrophoresis ◽  
Gel Electrophoresis ◽  
Serum Proteins ◽  
Clinical Laboratory ◽  
Charged Particles ◽  
Protein Electrophoresis ◽  
Agarose Gel Electrophoresis ◽  
Serum Samples ◽  
Routine Clinical Laboratory ◽  
Sample Dilution

Capillary electrophoresis is a technique that can be automated for the separation of charged particles. By investigating suitable sample dilution and injection time and adhering to a strict washing procedure we have been able to quantify paraproteins in serum samples. This has enabled us to use the technique of capillary electrophoresis for the provision of serum protein electrophoresis in a routine clinical laboratory. We present our findings of 260 serum samples, which included 76 samples with paraproteins analysed by both capillary electrophoresis (EC) and high resolution agarose gel electrophoresis (HRAGE). CE was able to detect all the monoclonal bands detected by HRAGE, and, in particular, better able to detect IgA monoclonal bands occurring in the beta region. The major advantages of CE over HRAGE relate to the automated nature of CE with the elimination of the need for a densitometer.

scholarly journals An Improved Continuous Flow Method for Serum Creatinine Using the Jaffé Reaction

1980 ◽  
Vol 17 (3) ◽  
pp. 153-154 ◽  
Author(s):  
W A White ◽  
E C Attwood
Keyword(s):  
Serum Creatinine ◽  
Continuous Flow ◽  
First Generation ◽  
Flow Method ◽  
Baseline Noise ◽  
Continuous Flow Method

A method for the measurement of creatinine is described in which serum is dialysed directly into a combined alkaline picrate reagent. Baseline noise and drift are eliminated, and precision is improved by avoiding the need to add further reagents after dialysis. This may be of particular interest to laboratories that perform this assay on first-generation AutoAnalyzer equipment.

Single- and coupled-enzyme nylon tube reactors for routine determination of pyruvate and lactate in serum.

1979 ◽  
Vol 25 (2) ◽  
pp. 285-288 ◽  
Author(s):  
P V Sundaram ◽  
W Hinsch
Keyword(s):  
Lactate Dehydrogenase ◽  
Continuous Flow ◽  
Clinical Laboratory ◽  
Low Cost ◽  
Serum Lactate ◽  
Tube Reactor ◽  
Nylon Tube ◽  
Lactate And Pyruvate ◽  
Routine Clinical Laboratory

Abstract We describe the use of a continuous-flow clinical analyzer with an immobilized coupled-enzyme nylon tube reactor and an immobilized single-enzyme nylon tube reactor for routine estimation of lactate and pyruvate in serum. These reactors are incorporated into the flow system of a modified continuous-flow analyzer (Technicon AutoAnalyzer). Results for serum lactate and pyruvate by this method are compared with those by corresponding methods in which the same enzymes are used in solution, either automatically (pyruvate) or manually (lactate) performed. Routine clinical laboratory determinations with use of the coupled-enzyme system lactate dehydrogenase and alanine aminotransferase, co-immobilized in the nylon tube reactor for estimation of lactate, and lactate dehydrogenase reactors for estimation of pyruvate give reliable and reproducible results with high precision at low cost.

Solid-Phase Radioimmunoassay of Thyroxine in Untreated Serum

1975 ◽  
Vol 21 (10) ◽  
pp. 1406-1413 ◽  
Author(s):  
John Seth ◽  
Frederick J Rutherford ◽  
Ian McKenzie
Keyword(s):  
Serum Proteins ◽  
Clinical Laboratory ◽  
Solid Phase ◽  
Gel Filtration ◽  
Serum Samples ◽  
Total Thyroxine ◽  
Solid Phase Radioimmunoassay ◽  
Technical Simplicity ◽  
Routine Clinical Laboratory ◽  
Antigen Antibody

Abstract We describe a simple, convenient solid-phase radioimmunoassay of total thyroxine in unextracted serum. Serum samples are added directly to the assay incubation mixture, interference in the antigen/antibody reaction by the thyroxine-binding serum proteins being almost completely eliminated by the addition of 8-anilino-1-naphthalene sulfonic acid and incubation at pH 10.5. Residual interference is compensated for by including thyroxine-free serum in the standards. Use of thyroxine antibodies that are coupled to a solid support permits separation of free and antibody-bound hormone by a single washing step, followed by centrifugation. The method is specific, accurate, and reasonably precise. The results obtained compare well with those for radioimmunoassay of thyroxine in serum freed of protein by gel filtration, and with results of a competitive protein-binding method. The technical simplicity of the procedure should readily permit automation. These features suggest that the technique should be well suited for routine clinical laboratory use.

Enzyme immunoassay with flow-amperometric detection of NADH.

1982 ◽  
Vol 28 (9) ◽  
pp. 1848-1851 ◽  
Author(s):  
H M Eggers ◽  
H B Halsall ◽  
W R Heineman
Keyword(s):  
Clinical Laboratory ◽  
Amperometric Detection ◽  
Electrochemical Technique ◽  
Serum Samples ◽  
Laboratory Procedure ◽  
Detection Range ◽  
Optimum Detection ◽  
Routine Clinical Laboratory ◽  
Good Agreement

Abstract Using phenytoin as a model analyte, we demonstrate that an enzyme-coupled immunoassay based on flow-injection analysis and amperometric detection of NADH is both feasible and practical. Good agreement with a routine clinical laboratory procedure for phenytoin was obtained for patients' serum samples. The electrode must be protected to prevent fouling by proteins in the analytical sample. The optimum detection range for NADH was at 0.01 of the concentrations of NADH generated during the several minutes required for each analysis. This suggests that the electrochemical technique should be extendable to the determination of species at concentrations in the microgram per liter range.

Determination of Thyroxine-Binding Globulin

1969 ◽  
Vol 15 (12) ◽  
pp. 1132-1140 ◽  
Author(s):  
R C Roberts ◽  
T F Nikolai
Keyword(s):  
Standard Deviation ◽  
Clinical Laboratory ◽  
Binding Capacity ◽  
Serum Samples ◽  
Thyroxine Binding Globulin ◽  
Total Thyroxine ◽  
The Mean ◽  
Routine Clinical Laboratory ◽  
Supernatant Solution

Abstract A method for determining thyroxine-binding globulin (TBG) concentration as the total thyroxine-binding capacity, has been developed. Prior electrophoretic separation of the three serum thyroxine-binding proteins is not required. Serum samples are diluted with a barbital-salicylate buffer pH 8.6, which inhibits thyroxine-binding by prealbumin. After incubation with 100 µg/100 ml thyroxine containing 131l-thyroxine, dextran-coated charcoal is added to the sample, which binds all the thyroxine not bound to TBG. The radioactivity in the supernatant solution is directly related to the concentration of TBG present. The Pearson’s correlation coefficient between the TBG results for this new assay and the polyacrylamide electrophoretic assay is 0.964. The mean TBG concentration and standard deviation for 80 normals was 19.2 ± 2.6 µg/100 ml. Pregnant women and women taking estrogens had a mean and standard deviation of 35.8 ± 4.8 µg/100 ml. Males from TBG-deficient families had TBG values of 5 µg/100 ml or less, and females from these families had values ranging from 8 to 12 µg/100 ml. The new assay is considerably simpler in equipment requirements and technic than the assays currently being used, and should be more practical for routine clinical laboratory use.

Type V Bekesy Pattern: Interpretation and Clinical Utility

1967 ◽  
Vol 10 (4) ◽  
pp. 733-744 ◽  
Author(s):  
William F. Rintelmann ◽  
Earl R. Harford
Keyword(s):  
Clinical Utility ◽  
The Past ◽  
Type V ◽  
Clinical Cases

Recent studies indicate there is some disagreement concerning the interpretation and clinical utility of the Type V Bekesy pattern. Bekesy tracings obtained over the past six years from a sample of clinical cases were analyzed and a definition was established for the Type V pattern. This definition was applied to Bekesy tracings obtained from normal listeners, hypoacusics, and pseudohypoacusics. The Type V pattern was found frequently among pseudohypoacusics and only rarely among other individuals.

A Hexagonal (II) Phase Phospholipid Neutralization Assay for Lupus Anticoagulant Identification

1993 ◽  
Vol 70 (05) ◽  
pp. 787-793 ◽  
Author(s):  
Douglas A Triplett ◽  
Linda K Barna ◽  
Gail A Unger
Keyword(s):  
Hemophilia A ◽  
Clinical Laboratory ◽  
Neutralization Assay ◽  
Confirmatory Test ◽  
Specific Factor ◽  
Clinical Settings ◽  
Drug Induced ◽  
Variable Screening ◽  
Routine Clinical Laboratory

SummaryLupus anticoagulants (LAs) are immunoglobulins (IgG, IgM, or both) which interfere with in vitro phospholipid (PL) dependent tests of coagulation (e.g. APTT, dilute PT, dilute Russell Viper Venom Time). These antibodies may be identified in a wide variety of clinical settings. With the exception of heparinized patient samples, the presence of LAs is often the most common cause of an unexplained APTT in a routine clinical laboratory. The diagnosis of LAs is difficult due to variable screening reagent sensitivity and intrinsic heterogeneity of LAs. Recently, Rauch and colleagues have shown human monoclonal hybridoma LAs were inhibited by hexagonal (II) phase PLs. In contrast, lamellar phase PLs had no effect. We have evaluated a new assay system, Staclot LA®, which utilizes a hexagonal (II) phase PL (egg phosphatidylethanolamine [EPE]) as a confirmatory test for LAs. Plasma samples from the following patient populations were studied: LA positive, heparinized, oral anticoagulated, hemophilia A and B, and specific factor inhibitors (factors V, VIII, IX). Unlike previous studies, the LA positive patients were a mixed population including: autoimmune diseases, drug-induced, and post-infection. Our findings confirm the specificity of hexagonal (II) phase PL neutralization of LAs.

scholarly journals Triangulating abuse liability assessment for flavoured cigar products using physiological, behavioural economic and subjective assessments: a within-subjects clinical laboratory protocol

BMJ Open ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. e023850
Author(s):  
Catherine S Wall ◽  
Rose S Bono ◽  
Rebecca C Lester ◽  
Cosima Hoetger ◽  
Thokozeni Lipato ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Subjective Effects ◽  
Latin Square ◽  
Abuse Liability ◽  
Smoke Inhalation ◽  
Nicotine Concentration ◽  
The Past ◽  
The Usa ◽  
Behavioural Economic ◽  
Scientific Meetings

IntroductionIn the USA, Food and Drug Administration regulations prohibit the sale of flavoured cigarettes, with menthol being the exception. However, the manufacture, advertisement and sale of flavoured cigar products are permitted. Such flavourings influence positive perceptions of tobacco products and are linked to increased use. Flavourings may mask the taste of tobacco and enhance smoke inhalation, influencing toxicant exposure and abuse liability among novice tobacco users. Using clinical laboratory methods, this study investigates how flavour availability affects measures of abuse liability in young adult cigarette smokers. The specific aims are to evaluate the effect of cigar flavours on nicotine exposure, and behavioural and subjective measures of abuse liability.Methods and analysesParticipants (projected n=25) are healthy smokers of five or more cigarettes per day over the past 3 months, 18–25 years old, naive to cigar use (lifetime use of 50 or fewer cigar products and no more than 10 cigars smoked in the past 30 days) and without a desire to quit cigarette smoking in the next 30 days. Participants complete five laboratory sessions in a Latin square design with either their own brand cigarette or a session-specific Black & Mild cigar differing in flavour (apple, cream, original and wine). Participants are single-blinded to cigar flavours. Each session consists of two 10-puff smoking bouts (30 s interpuff interval) separated by 1 hour. Primary outcomes include saliva nicotine concentration, behavioural economic task performance and response to various questionnaire items assessing subjective effects predictive of abuse liability. Differences in outcomes across own brand cigarette and flavoured cigar conditions will be tested using linear mixed models.Ethics and disseminationThe Virginia Commonwealth University Institutional Review Board approved the study (VCU IRB: HM20007848). Dissemination channels for study findings include scientific journals, scientific meetings, and policy briefs.Trial registration numberNCT02937051.

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