RADIOIMMUNOASSAY OF 3,3′-DI-IODOTHYRONINE IN UNEXTRACTED SERUM: THE EFFECT OF ENDOGENOUS TRI-IODOTHYRONINE

1978 ◽  
Vol 79 (3) ◽  
pp. 357-362 ◽  
Author(s):  
T. J. VISSER ◽  
L. M. KRIEGER-QUIST ◽  
R. DOCTER ◽  
G. HENNEMANN

The development of a highly sensitive and specific radioimmunoassay for 3,3′-di-iodothyronine (3,3′-T2) is described. The assay was applied to the measurement of 3,3′-T2 in unextracted human serum and used 8-anilino-l-naphthalene-sulphonic acid to inhibit the binding of 3,3′-T2 to serum transport proteins. The lower limit of detection of the assay was 2 fmol 3,3′-T2 per tube, which corresponded to 10 pmol 3,3′-T2/l serum. The mean concentration of 3,3′-T2 in normal serum was found to be 23 pmol/l, which is considerably lower than most values reported previously. Evidence is presented which suggests that the cross-reactivity of tri-iodothyronine with the antiserum to 3,3′-T2 is an important factor in the measurement of serum concentrations of 3,3′-T2 by radioimmunoassay.

1978 ◽  
Vol 24 (3) ◽  
pp. 414-419 ◽  
Author(s):  
A C Van Steirteghem ◽  
M H Zweig ◽  
A N Schechter

Abstract Measurement of the mass concentration of serum enzymes by radioimmunoassay provides direct quantitation of specific isoenzymes and may be less subject to some of the limitations of traditional assay procedures for enzymes. We describe the development of a sensitive and specific radioimmunoassay for the muscle isoenzyme of creatine kinase, CM-MM, in human serum. CK-MM, purified from human skeletal muscle, was used to raise high-titer antisera and for iodination by the Chloramine T method. The radioimmunoassay required 50 microliter of sample, utilized a double-antibody separation method, and was completed in 24 h. Cross reactivity with CK-BB was virtually zero, 3--17% with CK-MB. The mass concentration of CK-MM in the serum of healthy subjects ranged from 36 to 1668 microgram/liter and correlated closely with total CK enzymatic activity. Serum concentrations of CK-MM from casually selected patients correlated less well with total CK enzymatic activity, suggesting the existence of other CK isoenzymes or the presence of inactive forms.


2020 ◽  
Vol 16 (6) ◽  
pp. 744-752
Author(s):  
Kuan Luo ◽  
Xinyu Jiang

Background: Diabetes Mellitus (DM) is a major public metabolic disease that influences 366 million people in the world in 2011, and this number is predicted to rise to 552 million in 2030. DM is clinically diagnosed by a fasting blood glucose that is equal or greater than 7 mM. Therefore, the development of effective glucose biosensor has attracted extensive attention worldwide. Fluorescence- based strategies have sparked tremendous interest due to their rapid response, facile operation, and excellent sensitivity. Many fluorescent compounds have been employed for precise analysis of glucose, including quantum dots, noble metal nanoclusters, up-converting nanoparticles, organic dyes, and composite fluorescent microspheres. Silicon dot as promising quantum dots materials have received extensive attention, owing to their distinct advantages such as biocompatibility, low toxicity and high photostability. Methods: MnO2 nanosheets on the Si nanoparticles (NPs) surface serve as a quencher. Si NPs fluorescence can make a recovery by the addition of H2O2, which can reduce MnO2 to Mn2+, and the glucose can thus be monitored based on the enzymatic conversion of glucose by glucose oxidase to generate H2O2. Therefore, the glucose concentration can be derived by recording the fluorescence recovery spectra of the Si NPs. Results: This probe enabled selective detection of glucose with a linear range of 1-100 μg/mL and a limit of detection of 0.98 μg/mL. Compared with the commercial glucometer, this method showed favorable results and convincing reliability. Conclusion: We have developed a novel method based on MnO2 -nanosheet-modified Si NPs for rapid monitoring of blood glucose levels. By combining the highly sensitive H2O2/MnO2 reaction with the excellent photostability of Si NPs, a highly sensitive, selective, and cost-efficient sensing approach for glucose detection has been designed and applied to monitor glucose levels in human serum with satisfactory results.


2018 ◽  
Vol 74 (1) ◽  
pp. 6054-2018
Author(s):  
MAREK SZCZUBIAŁ ◽  
ROMAN DABROWSKI ◽  
WOJCIECH ŁOPUSZYŃSKI ◽  
MARIOLA BOCHNIARZ ◽  
MAGDALENA KRAWCZYK ◽  
...  

The aim of this study was the investigation of the circulating concentration of IGF-1 in female dogs with spontaneous mammary tumours. The study was performed on 34 female dogs undergoing surgery due to spontaneously occurring mammary gland tumours (24 malignant and 10 benign) and 10 clinically healthy fe-male dogs. The serum concentrations of IGF-1 were determined by specific ELISA Kit assay. The mean con-centrations of IGF-1 were significantly higher (P < 0.05) both in dogs with malignant (173.35 ± 120.45 ng/ml) and benign (130.58 ± 59.0 ng/ml) mammary tumours than in healthy controls (117.45±71.0 ng/ml). In the group of female dogs with mammary carcinomas, the mean concentration of IGF-1 gradually increased from 132.85 ± 65.64 ng/ml in dogs with grade 1 tumours to 317.74 ± 119.25 ng/ml in those with grade 3 tumours, and significant differences (P < 0.05) were found among dogs with various grade tumours. These findings suggest that circulating IGF-1 may play an important role in the pathogenesis of canine mammary tumour. Moreover, high IGF-1 levels may reflect tumour cell differentiation into a more aggressive phenotype. .


1988 ◽  
Vol 34 (2) ◽  
pp. 257-260 ◽  
Author(s):  
P E Ball ◽  
H Munzer ◽  
H P Keller ◽  
E Abisch ◽  
J Rosenthaler

Abstract A specific radioimmunoassay involving a mouse monoclonal antibody to cyclosporine has been developed for monitoring the parent drug in blood. Pretreatment with methanol removes cyclosporine from the erythrocytes. The limit of detection is about 12 micrograms/L, sample volume is 50 microL of blood, and within- and between-assay CVs are less than 7%. Assay results correlated well with those obtained by "high-performance" liquid chromatography (HPLC) for liver (n = 42), for heart (n = 64), for bone-marrow (n = 36), and for kidney (n = 140). For blood specimens obtained from patients treated with cyclosporine postoperatively for as long as 65 months, the mean RIA/HPLC ratio in all with transplant indications was close to 1. Therefore, the specific radioimmunoassay apparently can be used instead of HPLC to measure the parent drug in blood.


1978 ◽  
Vol 24 (3) ◽  
pp. 422-428 ◽  
Author(s):  
M H Zweig ◽  
A C Van Steirteghem ◽  
A N Schechter

Abstract We describe a sensitive, specific radioimmunoassay for the BB isoenzyme of creatine kinase (CK-BB) in serum. A sequential saturation assay was used to achieve sufficient sensitivity to detect the isoenzyme in 100-microliter serum samples of all healthy persons and patients tested. Bound and free antigen were separated by a second antibody system. Large excesses of purified isoenzyme MM did not react in the assay. Cross reactivity of two preparations of CK-MB was only 1 to 7+. The 95th percentile of serum CK-BB in 208 healthy adults was 6.2 microgram/liter. Within-assay and between-assay precision ranged from 5.5 to 11.9% and 9.7 to 13.6%, respectively.


1991 ◽  
Vol 37 (4) ◽  
pp. 504-507 ◽  
Author(s):  
Chizuko Ukita ◽  
Mitsushige Nishikawa ◽  
Akira Shouzu ◽  
Mitsuo Inada

Abstract We developed a simple and highly sensitive RIA for glycated protein (GP), and used it to measure GP in serum and urine from 15 normal controls and 30 diabetics (14 with urinary excretion rate of albumin, Ualb less than 15 micrograms/min, group A; nine with 15 less than or equal to Ualb less than or equal to 150 micrograms/min, group B; and seven with Ualb greater than 150 micrograms/min, group C). The mean serum concentration of GP was above normal in all groups of diabetics, and the mean glycation ratios of serum protein (SGP) were higher in groups B and C than in normal subjects. Urinary concentrations of GP also were increased in groups B and C, although the glycation ratio of urinary protein (UGP) was decreased in group C. Consequently, the selectivity of urinary excretion of GP (UGP/SGP) was significantly decreased in group C. Moreover, there was a significant difference in the mean values of selectivity between groups of patients with various degrees of retinopathy. We suggest that measurements of serum and urinary GP are useful to evaluate the progression of diabetic complications.


1990 ◽  
Vol 68 (4) ◽  
pp. 1576-1580 ◽  
Author(s):  
E. Zocca ◽  
L. M. Fabbri ◽  
P. Boschetto ◽  
M. Plebani ◽  
M. Masiero ◽  
...  

We investigated whether leukotriene B4 (LTB4) is released from the lungs of sensitized subjects during asthmatic reactions induced by toluene diisocyanate (TDI). We examined three groups of TDI-sensitized subjects, one after no exposure to TDI, the second 8 h after an exposure to TDI that caused an early asthmatic reaction, and the third 8 h after an exposure to TDI that caused a late asthmatic reaction. We analyzed bronchoalveolar lavage (BAL) fluid by reverse-phase high-performance liquid chromatography and by specific radioimmunoassay. The mean concentration of LTB4 was higher [0.31 +/- 0.09 (SE) ng/ml, range 0.15-0.51] in BAL fluid of sensitized subjects who developed a late asthmatic reaction than in BAL fluid of subjects who developed an early asthmatic reaction (0.05 +/- 0.04 ng/ml, range 0-0.224), and no LTB4 was detectable in the control subjects. We also performed BAL 8 h after TDI exposure on four TDI-sensitized late-dual reactors who were on steroid treatment. In this group of subjects no LTB4 was detectable. These results suggest that LTB4 may be involved in late asthmatic reactions induced by TDI.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Shuang Han ◽  
Yifeng Xue ◽  
Junlan Zhang ◽  
Jianrong Huang ◽  
Xiuxia Liu ◽  
...  

A chemiluminescent immunoassay for human serum osteocalcin, or bone Gla protein, was established using a double-antibody sandwich model. Examination of the hook effect revealed that it was significantly reduced, and no hook effect was observed at an osteocalcin concentration of 4000 ng/mL. The established method showed good analytical performance and thermal stability. The limit of detection was 0.03 ng/mL. The intra-assay coefficient of variation (CV) was 3.22%–5.64%, the interassay CV was 4.42%–7.25%, and the recovery rate was 93.22%–107.99%. Cross-reactivity (CR) was not observed with bovine, rat, mouse, rabbit, or porcine samples. The developed method showed a good correlation with the N-MID product from Roche. In total, 1069 clinical patient samples were measured using the reagent kit developed in this study.


1992 ◽  
Vol 38 (10) ◽  
pp. 1968-1974 ◽  
Author(s):  
J Jaouhari ◽  
F Schiele ◽  
S Dragacci ◽  
P Tarallo ◽  
J P Siest ◽  
...  

Abstract We describe a competitive enzyme immunoassay, the ExtrAvidin-biotin system, for determining osteocalcin in human serum or plasma. Antibodies were raised against bovine osteocalcin. Binding of the antibodies to osteocalcin was calcium-dependent. Limit of detection is 0.07 nmol/L (0.4 microgram/L). The standard curve for method is linear between 0.3 and 17.6 nmol/L (1.9 and 100 micrograms/L). Interassay CV over the range 0.9 to 14.8 nmol/L (5.3 to 84 micrograms/L) is 7.5% to 11.7%. Analytical recovery is 105% +/- 5% (mean +/- SD). The measurement, which is adapted to microtiter plates, requires only 20 microL of serum and 5 h. The coefficient of correlation between the concentrations measured by this method and by a commercially available radioimmunoassay kit (CIS Biointernational) is 0.91. Osteocalcin can be measured in serum or heparinized plasma. Hemolysis (174 mumol/L hemoglobin) reduces osteocalcin concentration by 54%. High concentrations of triglycerides (7 mmol/L) give an overestimation of 63%. Serum concentrations of osteocalcin measured in 130 healthy subjects (ages 15-64 years) and 86 children (ages 4-14 years) were 1.4 +/- 0.8 and 4.0 +/- 1.5 nmol/L (8.1 +/- 4.6 and 22.5 +/- 8.6 micrograms/L), respectively (mean +/- SD).


1975 ◽  
Vol 21 (11) ◽  
pp. 1658-1662 ◽  
Author(s):  
Charles J Least ◽  
George F Johnson ◽  
Harvey M Solomon

Abstract We describe a sensitive and precise gas-chromatographic method in which benzylmalonate methylester monoamide is used as the internal standard for the simultaneous determination of primidone, phenylethylmalonamide, carbamazepine, and diphenylhydantoin. The trimethylsilyl derivatives of the anticonvulsants are well separated from each other and from normal serum constituents. The lower limit of detection for each drug is 0.5 mg/liter when 1 ml of serum is analyzed. Withinrun precision (CV), established by analysis of 10 replicates, was as follows: primidone (5.4 mg/liter), 2.6%; phenylethylmalonamide (5.5 mg/liter), 1.6%; diphenylhydantoin (6.6 mg/liter), 3.8%; and carbamazepine (10.4 mg/liter), 3.2%. Fifty specimens were analyzed for primidone and 35 for diphenylhydantoin by a standard gas-chromatographic method involving on-column methylation and by the procedure we have developed. The mean value observed for primidone with the on-column alkylation procedure was 9.3 mg/liter and with our procedure was 9.6 mg/liter. When values for our assay were regressed against values for the standard method, the slope of the least-squares line was 0.936, the intercept was 1.00 mg/liter, and r was 0.939. The mean values observed for diphenylhydantoin by on-column methylation and with our procedure were both 12.6 mg/liter. When values for our assay were regressed against the standard method, the slope of the leastsquares line was 0.944, the intercept was 0.3 mg/liter, and r was 0.988


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