Digoxin-like immunoreactivity in normal human plasma and urine, as detected by a solid-phase radioimmunoassay.

1984 ◽  
Vol 30 (3) ◽  
pp. 450-451 ◽  
Author(s):  
S Balzan ◽  
A Clerico ◽  
M Grazia del Chicca ◽  
U Montali ◽  
S Ghione

Abstract Reports on the presence of digoxin-like immunoreactive substance(s) (DLIS) in the plasma and urine of several animal species and a few human test subjects prompted us to undertake to confirm the presence of DLIS in plasma and urine of normal persons and to investigate some characteristics of this antibody-DLIS binding. For this purpose we used a modified radioimmunoassay kit involving antidigoxin antibody-coated test tubes and 125I-labeled digoxin to measure DLIS in urine and concentrated plasma of ostensibly healthy subjects. In 12 separate experiments with plasma the mean sensitivity was 5.12 (SD 1.11) pg per tube, expressed as digoxin. There was no significant cross reactivity with human serum albumin in concentrations up to 200 g/L. The mean DLIS value (in digoxin equivalents) for plasma from 24 normal subjects was 33.58 (SD 14.24) ng/L. Its mean concentration in urine from five subjects was 315.00 (SD 91.38) ng/L.

1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.


1982 ◽  
Vol 52 (1) ◽  
pp. 109-113 ◽  
Author(s):  
H. A. Jones ◽  
J. C. Clark ◽  
E. E. Davies ◽  
R. E. Forster ◽  
J. M. Hughes

The rate of uptake of carbon monoxide (CO) in the lungs of normal subjects were measured at inspired concentrations of less than 1, 300, and 3,000 ppm (less than 0.0001–0.3%) using radioactive CO (11CO). In nine subjects the rate of uptake was monitored at the mouth during rebreathing. At inspired CO concentrations of approximately 1, 300, and 3,000 ppm and a mean alveolar O2 fraction of 0.15, the mean lung diffusing capacity was 25.8, 26.4, and 25.3 ml . min-1. Torr-1, respectively. In seven subjects the measurements were repeated after a period of O2 breathing, giving a mean alveolar O2 fraction of 0.78. The calculated membrane diffusing capacity was 31.9, 33.7, and 32.0 ml . min-1. Torr-1 at less than 1, 300, and 3,000 ppm inspired CO. We conclude that there is no difference in the rate of uptake of CO over the range of concentrations studied in these experiments. No evidence for the presence of a facilitated transport system for CO in the normal human lung was found.


1971 ◽  
Vol 40 (4) ◽  
pp. 327-336 ◽  
Author(s):  
W. C. Dick ◽  
S. D. Deodhar ◽  
Carol J. Provan ◽  
G. Nuki ◽  
W. W. Buchanan

1. Uptake of intravenously administered radioactive technetium (99mTc) was measured over the knee joints in normal human volunteers, in patients with osteoarthritis and in groups of synovectomized and unoperated patients with rheumatoid arthritis. The uptake was compared with clinical indices of inflammation (pain, tenderness swelling and stiffness), and the clearance rate of intra-articularly injected radioactive xenon (133Xe). The 99mTc uptakes were found to be unrelated to the isotope dose and the day-to-day reproducibility was acceptable. 2. The mean uptake of 99mTc was within normal limits in osteoarthritis. Both in synovectomized and in unoperated rheumatoid arthritis 99mTc uptake was significantly higher than in normal subjects. 3. Of the clinical indices studied significant correlation of 99mTc uptake was found with pain and swelling in all groups of patients studied. 4. Faster clearance of 133Xe in unoperated rheumatoid arthritis correlated well with the higher 99mTc uptakes. 5. The results confirm that 99mTc uptakes are raised in inflammatory arthritis but not in degenerative arthritis. The relation of 99mTc uptake to the clinical indices of inflammation and to the 133Xe clearance from the joint is discussed.


2005 ◽  
Vol 91 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Dario Cotesta ◽  
Chiara Caliumi ◽  
Piero Alò ◽  
Luigi Petramala ◽  
Maria Gabriella Reale ◽  
...  

Aims and background The aim of our study was to investigate the plasma chromogranin A (CgA) and adrenomedullin (AM) levels in patients with pheochromocytomas. Methods and study design We collected blood samples for measurement of plasma CgA and AM in 21 patients with pheochromocytomas, 43 healthy subjects and 26 patients with solid non-functioning adrenocortical adenomas. In 11 patients with pheochromocytomas plasma CgA and AM were measured again four weeks after tumor removal. CgA and AM were measured by means of a novel solid-phase two-site immunoradiometric assay based on monoclonal antibodies (CgA-RIA CT, CIS bio international) and by a specific radioimmunoassay (RIA, Phoenix Pharm. Inc.), respectively. Results The mean plasma CgA level (±SD) in patients with pheochromocytomas (204 ± 147.9 ng/mL) was significantly higher (P <0.001) than that in healthy subjects (41.6 ± 10.7 ng/mL) and in patients with non-functioning adrenocortical adenomas (47.3 ± 17.6 ng/mL). The mean plasma AM concentration (±SD) in patients with pheochromocytomas (27.5 ± 10.4 pg/mL) was significantly higher (P <0.001) than that in HS (13.8 ± 4.5 pg/mL) and in patients with non-functioning adrenocortical adenomas (16.6 ± 7.3 pg/mL). Plasma CgA levels correlated with plasma AM levels (r = 0.501; P <0.02) and with plasma metanephrine levels (r = 0.738; P <0.0001) in patients with pheochromocytomas. In 11 patients with pheochromocytomas plasma CgA and AM concentrations significantly decreased after tumor removal (P <0.001 for both). Circulating CgA and AM had a sensitivity of 76.2% and 81%, a specificity of 97.7% and 90.7%, and an accuracy of 91% and 88%, respectively. Conclusion This study demonstrates that circulating CgA and AM levels are increased in pheochromocytoma patients compared with healthy subjects and patients with non-functioning adrenocortical adenomas. Moreover, at the time of diagnosis plasma CgA levels correlated with plasma AM levels and with plasma metanephrine levels in all patients with pheochromocytomas. In conclusion, plasma CgA and AM concentrations may represent additional biochemical parameters for clinical monitoring of patients with pheochromocytomas.


1986 ◽  
Vol 32 (1) ◽  
pp. 80-83 ◽  
Author(s):  
A E Steiner ◽  
J L Wittliff

Abstract We used a whole-cell glucocorticoid receptor assay to examine characteristics of the glucocorticoid receptor in the lymphocytes of normal human donors. We measured binding of [3H]dexamethasone to the lymphocytes of four different donors on several different occasions; the variation about the mean for the assays was +/- 15%. Whole-cell assays in 15 normal subjects showed a mean value of 6.18 fmol/10(6) cells or 3722 sites per cell, with a somewhat higher level in men (7.67 fmol/10(6) cells, or 4620 sites per cell) than women (4.48 fmol/10(6) cells, or 2698 sites per cell). We saw no correlation between donor age and receptor values, in either group. Assays in which we used [3H]prednisolone demonstrated similar binding properties as with [3H]dexamethasone. The mean glucocorticoid receptor value for normal human T-cells from three donors was 2.52 fmol/10(6) cells, or 1518 sites per cell.


1976 ◽  
Vol 128 (2) ◽  
pp. 184-187 ◽  
Author(s):  
Helen L. White ◽  
Malcolm N. McLeod ◽  
Jonathan R. T. Davidson

SummaryCatechol O-methyltransferase of lysed human red blood cells was assayed under optimal conditions, using saturating concentrations of the substrates, S-adenosyl-L-methionine and 3,4-dihydroxybenzoic acid. The mean enzyme activity found in 24 normal subjects was 29.2 nmol/hr/ml RBC. The mean activity in blood of 33 female unipolar depressives was not significantly different from normal. However, higher enzyme activities were observed in the blood of 11 schizophrenic patients (38.9 nmol/hr/ml RBC). Partially purified enzyme preparations from blood of normal and schizophrenic individuals were indistinguishable with respect to substrate specificities, isoelectric pH values, and ratios of the two O-methylated products. Therefore it is unlikely that any defect in O-methylation which may occur in schizophrenia can be attributed to a change in the intrinsic properties of erythrocyte catechol O-methyltransferase.


2003 ◽  
Vol 16 (2) ◽  
pp. 129-138
Author(s):  
C. Konidaris ◽  
P.G. Mitlianga ◽  
G.K. Papadopoulos

The 65 kD isoform of Glutamic Acid Decarboxylase (GAD), is one of the major autoantigens in human type 1 diabetes mellitus. This enzyme shares aminoacid identity, in select regions already determined as antigenic with its counterpart from E. coli. We tested the reactivity of diabetic and normal sera and an E. coli GAD-specific monoclonal antibody (2D9) to E. coli GAD by solid phase and competition ELISA, as well as immunoblotting to check for cross-reactivity of autoantibodies to the two antigens. Specific antibodies for E. coli GAD are present in diabetics and normal subjects without any differences in frequency and titer. The reactivity of such antibodies in ELISA could be blocked in a dose-dependent manner by the addition of excess antigen in the liquid phase. Furthermore, the monoclonal antibody against E. coli GAD does not recognise human recombinant GAD65 in an ELISA. We conclude that there is no basis for cross-reactivity between the two antigens, and antibody reactivity to GAD65 in man cannot arise from cross-reactivity to the E. coli enzyme.


Author(s):  
Linda M. Morgan ◽  
Brian A. Morris ◽  
Vincent Marks

Summary A radioimmunoassay for the measurement of gastric inhibitory polypeptide (GIP) in unextracted plasma in man has been developed using a rabbit antiserum raised against porcine GIP. Porcine GIP was employed also as standard and to produce a 125I-labelled tracer. The assay was able to distinguish 110 pg/ml GIP from zero in plasma samples. Negligible cross-reactivity was demonstrated with cholecystokinin, insulin, pancreatic polypeptide, glucagon, secretin, and vasoactive intestinal polypeptide. The mean overnight fasting plasma GIP level in 28 normal subjects was 203 pg/ml (range: undetectable—420 pg/ml). Plasma GIP levels rose, within 45 minutes of eating a mixed meal, to a mean level of 1573 pg/ml.


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.


1988 ◽  
Vol 34 (8) ◽  
pp. 1591-1593 ◽  
Author(s):  
R Bützow ◽  
H Alfthan ◽  
U H Stenman ◽  
A M Suikkari ◽  
H Bohn ◽  
...  

Abstract This time-resolved immunofluorometric assay (IFMA) developed for measurement of placental protein 5 (PP5) involves two antibodies: a monoclonal anti-PP5 antibody attached to a solid phase and an europium(III) chelate-labeled polyclonal anti-PP5 antibody as a tracer. The measuring range is 0.05-100 micrograms/L and the detection limit is 20 times lower than that of a PP5 radioimmunoassay (RIA) performed with the same polyclonal antiserum. By IFMA, PP5 could be detected and quantified in all plasma and serum samples of nonpregnant and pregnant individuals, whereas PP5 was undetectable by RIA in serum of healthy men and nonpregnant women. The mean concentration of PP5 in sera from men was 0.43 micrograms/L (SD 0.13, range 0.19-0.75, n = 47) and in sera from nonpregnant women 0.49 micrograms/L (SD 0.19, range 0.20-0.90, n = 41). PP5 concentrations in serum showed no systematic variation during the menstrual cycle. In serum samples from 60 pregnant women the results obtained by IFMA and RIA correlated well (r = 0.97).


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