scholarly journals Determination of serum triglycerides by an accurate enzymatic method not affected by free glycerol.

1985 ◽  
Vol 31 (7) ◽  
pp. 1227-1228 ◽  
Author(s):  
D R Sullivan ◽  
Z Kruijswijk ◽  
C E West ◽  
M Kohlmeier ◽  
M B Katan

Abstract In this automated single-run enzymatic procedure for specific determination of triglycerides in serum, free glycerol is removed from the reaction mixture by pre-incubation with glycerol phosphate oxidase and peroxidase. The subsequent addition of lipase and the chromogen, 4-aminoantipyrine, results in the formation of color proportional to the amount of triglycerides in serum. Standards containing triolein in aqueous detergent are used to calibrate the method. For serum pools from the Centers for Disease Control with target values of 0.74, 1.41, and 2.63 mmol/L, the method produced biases of +0.01, -0.05, and 0.00 mmol/L, respectively (mean: -0.01 mmol/L or -0.4%). The mean coefficient of variation was 1.4% within and 2.5% between days; the combined CV, 2.9%. Ninety 6-microL serum samples can be analyzed per hour. The method is more accurate and precise than one based on an NADH-coupled enzyme system with separate addition of lipase.

1994 ◽  
Vol 40 (1) ◽  
pp. 52-55 ◽  
Author(s):  
H E van Ingen ◽  
H J Huijgen ◽  
W T Kok ◽  
G T Sanders

Abstract We performed an analytical evaluation of a commercially available instrument for determining ionized magnesium through use of a neutral carrier, liquid-membrane-based ion-selective electrode. Reproducibility (CV 2-4%), linearity (0.30-2.50 mmol/L), lower limit of detection (0.30 mmol/L), and absence of interference from Ca2+ indicate adequate performance for measuring ionized magnesium in plasma or serum samples in the normal to high-concentration range. Sodium in excess of 150 mmol/L caused a negative bias, which can be explained by ionic strength-induced changes in activity coefficients. The use of heparin as an anticoagulant must be restricted to concentrations < 15 units/mL because of the binding of magnesium to heparin. The mean +/- SD concentration of ionized magnesium and its fraction of total magnesium in 76 healthy volunteers were 0.56 +/- 0.05 mmol/L and 0.65 +/- 0.04, respectively.


2012 ◽  
Vol 69 (5) ◽  
pp. 389-393 ◽  
Author(s):  
Snezana Djordjevic ◽  
Vesna Kilibarda ◽  
Slavica Vucinic ◽  
Tomislav Stojanovic ◽  
Biljana Antonijevic

Background/Aim. Saliva is a body fluid which, like serum, can be used for determination of concentrations of certain drugs, both in pharmacotherapy as well as in acute poisonings. The aim of this study was to determine carbamazepine concentrations in both saliva and serum in acute poisoning in order to show if there is a correlation between the obtained values, as well as to monitor toxicokinetics of carbamazepine in body fluides. Methods. Saliva and serum samples were obtained from 26 patients treated with carbamazepine and 20 patients acutely poisoned by the drug immediately after their admission in the Emergency Toxicology Unit. Determination of salivary and serum carbamazepine concentrations was performed by the validated high pressure liquid chromatographyultraviolet (HPLC-UV) method. Results. A significant correlation of salivary and serum carbamazepine concentrations in both therapeutic application and acute poisoning (r = 0.9481 and 0.9117, respectively) was confirmed. In acute poisonings the mean ratio between salivary and serum concentrations of carbamazepine (0.43) was similar to the mean ratio after its administration in therapeutic doses (0.39), but there were high inter-individual variations in carbamazepine concentrations in the acutely poisoned patients, as a consequence of different ingested doses of the drug. In acute poisoning the halftime of carbamazepine in saliva and serum was 12.57 h and 6.76 h, respectively. Conclusion. Our results suggest a possible use of saliva as an alternative biological material for determination of carbamazepine concentrations in therapeutic application and acute poisoning as well, and a possible extrapolation of the results obtained in saliva to serum concentrations of carbamazepine.


1965 ◽  
Vol 11 (6) ◽  
pp. 617-623 ◽  
Author(s):  
Than Myint ◽  
Harold B Houser

Abstract This simplified thiochrome method for the determination of thiamine eliminates deproteinization, sample dilution (other than reagent), and purification by adsorption column; pH need not be adjusted as it is automatically controlled. The method depends upon the hydrolysis of whole blood and serum with N HCI, N/10 HCI, and diastase enzyme. Reproducibility was good; the mean differences (± S.D.) between duplicate blood and serum samples were 2.36 ± 2.87 and 1.5 ± 1.70 mµg./ml., respectively. Recovery of added thiamine ranged from 94 to 104% with a mean of 99.5 ± 3.41%. Storage of hydrolysates for 30 days did not change the results, and low serum concentrations could be measured in serum. Whole blood and serum values of thiamine in 44 healthy adults ranged from 11.3 to 47.8 mµg./ml. (mean, 29.3) and from trace amounts to 20.5 mµg./ml. (mean, 10.2), respectively.


2003 ◽  
Vol 42 (04) ◽  
pp. 157-166 ◽  
Author(s):  
K. Brandt-Mainz ◽  
L. Freudenberg ◽  
A. Frilling ◽  
W. Grimm ◽  
A. Bockisch ◽  
...  

Summary: Aim of our study was to evaluate the increasing sensitivity within three generations of thyroglobulin (Tg) as-says, which were available during the past decade, and its clinical impact for patients with differentiated thyroid carcinoma. Methods: Determination of Tg using the IRMA introduced in 1989 (Dynotest®Tg, Henning Berlin, Berlin; assay A) and 1994 (Selco®Tg, Medipan Diagnostica, Selchow; assay B), as well as the IEMA available recently (Medizym®Tg Rem, Medipan Diagnostica, Selchow; assay C). Results: We found a close correlation between the measurable Tg values of assay A and B (r = 0.985; p <0.001) as well as assay B and C (r = 0.978; p <0.001). Assay B (lowest detection limit: 0.3 ng/ml) was more than twice as sensitive as assay A and did not show quite as many disturbances of recovery (in 0.5% versus 4% of our patients). Due to its strict calibration to the European reference preparation CRM 457, Tg values determined by assay C were in the mean 1.9-fold higher than by assay B. Thus, with its functional sensitivity of 0.03 ng/ml assay C is nearly 20-fold more sensitive than assay B. Whereas the proportion of measurable Tg values was only 22% in a selected group of patients (criterion of inclusion: Tg in assay B ≤1 ng/ml with TSH-suppressive conditions; n = 317 serum samples from 103 patients), it was 68% in assay C, with good intraindividual reproducibility of these values in the course. Conclusion: The ultrasensitive assay C is especially suitable for the follow-up of treated thyroid cancer patients being considered as cured, and may shorten the time interval until the detection of a recurrence markedly: the gain of time calculated from the Tg courses in patients with a gradually progressive tumor relapse ranged from 5 to 15 months.


2011 ◽  
Vol 3 (02) ◽  
pp. 104-109 ◽  
Author(s):  
Venencia Albert ◽  
Arulselvi Subramanian ◽  
Kanchana Rangarajan ◽  
Ravindra Mohan Pandey

ABSTRACT Aim: The aim of our study was to do an agreement analysis of two different laboratory methods used to measure electrolytes i.e., between the ISE based Beckman Coulter Synchron CX9 PRO Biochemistry analyzer and RAL′s Ion3 Flame Photometer (Técnica para el Laboratorio, Barcelona, Spain), in serum samples. Materials and Methods: This cross sectional study was done over a period of three months from September′09 through December′09 on routine biochemistry samples. A total of 6492 samples were received for routine biochemistry analysis from those 630 blood samples were randomly processed for this study. Two ml of sample was taken in a plain gel tube (LABTECH Disposables, Ahmedabad, India), centrifuged and further processed using both systems within one hour of the sampling to obtain the Na and K concentrations in the samples. The bias and variability of differences in measured values were analyzed according to Bland and Altman method. Results: Flame photometry method has drawbacks such as low throughput, requires manual operation, is a time consuming procedure. Ion selective electrodes technique is a more universal method for the high throughput determination of electrolytes in physiological samples; Beckman Coulter Synchron CX9 PRO is an example of such a system. The mean difference between the two methods (standard minus test) and 95% limits of agreement for sodium in serum was -7.8±17.3 (-42.2 to 26.6) and in urine was -22±41 (-104 to 60). Similarly, the mean difference between the two methods for potassium values in serum was found to be -0.25±0.75 (-1.75 to 1.25) and in urine was -5.3±38.9 (-83.1 to 72.5). With 95% confidence interval, the value of sodium and potassium as determined by both the methods lie between the upper and lower limit showing 95% limits of agreement. Conclusion: Good degree of agreement was seen on comparing the two methods for measuring the electrolytes; the use of Synchron CX9 in place of Flame photometer for electrolyte analysis in serum and urine is justified or use the two interchangeably.


Bionatura ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 1970-1973
Author(s):  
Faezeh Ghasemi ◽  
Alireza Kamali ◽  
Maryam Shokrpour

Oxidative stress has been identified to play a vital role in the pathogenesis of spontaneous abortion were characterized as an imbalance between the generation of pro-oxidants, free radicals, and reactive species, and enzymatic and non-enzymatic antioxidant defenses in favor of the former. In the present study, the pro-oxidant-antioxidant balance was assessed in women with spontaneous abortion and compared with healthy age-matched controls. A group of 50 females with spontaneous abortion were considered patients, and a group of age-matched healthy pregnant women was considered controls. The pro-oxidant-antioxidant balance (PAB) assay was carried out on participants' serum samples. The mean age of the spontaneous abortion group was 30.84 ± 3.82, and controls were 26.53 ± 4.05 years. The obtained PAB values were 236.74 ± 11.37 HK and 148.69 ± 76.50 HK in patients and controls. Our results demonstrate the significant rise of PAB values in subjects with spontaneous abortion compared to healthy controls (p< 0.0001). Our study showed that the PAB values might be involved in the termination of spontaneous abortion.


2001 ◽  
Vol 84 (5) ◽  
pp. 1363-1370 ◽  
Author(s):  
Marta M D C Vila ◽  
Matthieu Tubino ◽  
Graciliano de Oliveira Neto

Abstract A flow injection (FI) enzymatic system, based on the use of immobilized salicylate hydroxylase in glass beads, was developed for the determination of salicylate. Salicylate hydroxylase and nicotinamide adenine dinucleotide (NADH) are used to convert salicylate to catechol. The reaction of catechol with 4-aminophenol at high pH yields a colored product which is detected spectrophotometrically at 565 nm. Ten samples of human serum containing from 5.0 × 10−4 to 5.0 × 10−3 mol/L added salicylate were analyzed and the recovery was determined. Eight additional serum samples containing salicylate were analyzed by the Trinder test and the proposed method. The results obtained with the 2 methods showed good agreement by the statistical Student's t-test. The relative precision of the method is about 3.4% (RSD of the mean recovery). Considering the lowest concentration analyzed, the quantitative limit of detection is about 0.2 × 10−5 mol/L (3 × SD). The volume of the sample used was 150 μL. The proposed method was also used to analyze medicines containing acetylsalicylic acid. The results were statistically compared with those obtained through the U.S. Pharmacopoeia procedure and showed excellent agreement.


1969 ◽  
Vol 15 (12) ◽  
pp. 1132-1140 ◽  
Author(s):  
R C Roberts ◽  
T F Nikolai

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.


1976 ◽  
Vol 22 (8) ◽  
pp. 1310-1313 ◽  
Author(s):  
S H Grossman ◽  
E Mollo ◽  
G Ertingshausen

Abstract We describe a totally enzymatic method for determination of serum triglycerides (triacylglycerols) specifically adaptable to the CentrifiChem system. The method involves lipolysis with lipase from Rhizopus arrhizus alone and quantitation of the resulting glycerol with glycerol dehydrogenase in a kinetic, fixed-time mode. Hydrolysis by the lipase is complete, for concentrations up to at least 5.0 g/liter, in 10 min at room temperature. The unfavorable equilibrium for the oxidation of glycerol is overcome by increasing the pH and adding excess NAD+. Under these conditions the glycerol determination is linear to at least 4.0 g of glycerol per liter, as triglyceride. The test exhibits acceptable accuracy and precision, and results correlate well with those by an alternative totally enzymatic procedure. The present method is unaffected by phosphatase and a considerably simplified reagent is used.


1996 ◽  
Vol 76 (06) ◽  
pp. 0925-0931 ◽  
Author(s):  
John F Carroll ◽  
Keith A Moskowitz ◽  
Niloo M Edwards ◽  
Thomas J Hickey ◽  
Eric A Rose ◽  
...  

SummaryTwenty-one cardiothoracic surgical patients have been treated with fibrin as a topical hemostatic/sealing agent, prepared from bovine fibrinogen clotted with bovine thrombin. Serum samples have been collected before treatment with fibrin and postoperatively between 1 and 9 days, 3 and 12 weeks, and 6 and 8 months. The titers of anti-bovine fibrinogen antibodies, measured by ELISA specific for immunoglobulins IgG or IgM, increased to maximal values after about 8 or 6 weeks, respectively. After 8 months, IgG titers were on average 20-fold lower than the mean maximal value, while IgM titers returned to the normal range. IgG was the predominant anti-bovine fibrinogen immunoglobulin as documented by ELISA, affinity chromatography and electrophoresis. Anti-bovine fibrinogen antibodies present in patients reacted readily with bovine fibrinogen, but did not cross-react with human fibrinogen as measured by ELISA or by immunoelectrophoresis. A significant amount of antibodies against bovine thrombin and factor V has been found, many cross-reacting with the human counterparts. No hemorrhagic or thrombotic complications, or clinically significant allergic reactions, occurred in any patient, in spite of antibody presence against some bovine and human coagulation factors. The treatment of patients with bovine fibrin, without induction of immunologic response against human fibrinogen, appeared to be an effective topical hemostatic/sealing measure.


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