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Sample records for c-peptide determination radioimmunoassay

  1. Diagnostic value of C-peptide determination. [Radioimmunoassay

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    Kober, G; Rainer, O H [Landeskrankenhaus Klagenfurt (Austria). Nuklearmedizinische Abt.

    1983-01-01

    C-peptide and insulin serum determinations were performed in 94 glucagon-stimulated diabetics and in 15 healthy persons. A minimal increase of 1.5 ng C-peptide/ml serum after glucagon injection (1 mg i.v.) was found to be a useful parameter for the differentiation of insulin dependent and non-insulin dependent diabetics. The maximal response to glucagon occurred during the first 10-minutes after the injection (blood was drawn at 2-minutes intervals). Serum insulin levels and basal C-peptide concentrations were of no value in predicting insulin-dependency. Basal C-peptide levels were significantly different from control in juvenile insulin dependent diabetics (decrease) only.

  2. Human C-peptide. Pt. 1. Radioimmunoassay

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    Beischer, W; Keller, L; Maas, M; Schiefer, E; Pfeiffer, E F [Ulm Univ. (Germany, F.R.). Abt. Innere Medizin, Endokrinologie und Stoffwechsel

    1976-08-01

    Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with /sup 125/iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum.

  3. Automatic computation of radioimmunoassay data. Insulin and C-peptide

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    Toyota, T; Kudo, M; Abe, K [Hirosaki Univ., Aomori (Japan). School of Medicine; Kawamata, F; Uehata, S

    1975-09-01

    Radioimmunoassay provided dose response curves which showed linearity by the use of logistic transformation (Rodbard). This transformation which was applicable to radioimmunoassay should be useful for the computer processing of insulin and C-peptide assay. In the present studies, standard curves were analysed by testing the fit of analytic functions to radioimmunoassay of insulin and C-peptides. A program for use in combination with the double antibody technique was made by Dr. Kawamata. This approach was evidenced to be useful in order to allow automatic computation of data derived from the double antibody assays of insulin and C-peptides. Automatic corrected calculations of radioimmunoassay data of insulin was found to be satisfactory.

  4. Measurement of plasma canine C peptide by radioimmunoassay

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    Besch, W; Woltanski, K P; Fischer, U; Kohnert, K D; Ziegler, M

    1985-12-01

    A sensitive radioimmunoassay for canine C peptide (CCP) was established using synthetic CCP, a specific antiserum, and rabbit anti-guinea pig serum. Radioiodination was performed according to a modified chloramine T method. Tracer preparations have been used for 6 weeks after iodination. The standard curve ranges from 0.028 to 3.0 nmol/l. The intra-assay coefficient of variation (CV) was 3-5% and the inter-assay CV was 6-9% in the optimal range between 0.3 and 0.8 nmol/l. The average recovery of CCP added to plasma samples was 100.6% (n = 9). Canine insulin, porcine proinsulin, bovine proinsulin, and human C peptide exhibited no cross-reactivity. The mean fasting plasma CCP concentration was 0.089 +- 0.021 nmol/l in normal dogs and -0.005 +- 0.007 nmol/l (mean +- SEM) in diabetic dogs, respectively.

  5. Insulin and C-peptide in human brain neurons (insulin/C-peptide/brain peptides/immunohistochemistry/radioimmunoassay)

    International Nuclear Information System (INIS)

    Dorn, A.; Bernstein, H.G.; Rinne, A.; Hahn, H.J.; Ziegler, M.

    1983-01-01

    The regional distribution and cellular localization of insulin and C-peptide immunoreactivities were studied in human cadaver brains using the indirect immunofluorescence method, the peroxidase-antiperoxidase technique, and radioimmunoassay. Products of the immune reactions to both polypeptides were observed in most nerve cells in all areas of the brain examined. Immunostaining was mainly restricted to the cell soma and proximal dendrites. Radioimmunoassay revealed that human brain contains insulin and C-peptide in concentrations much higher than the blood, the highest being in the hypothalamus. These findings support the hypothesis that the 'brain insulin' is - at least in part - produced in the CNS. (author)

  6. A study on the C-peptide radioimmunoassay with synthetized connecting peptide

    International Nuclear Information System (INIS)

    Nakagawa, Shoichi; Sasaki, Takashi; Nakayama, Hidetaka; Watanabe, Takuji; Aoki, Shin

    1976-01-01

    A method of C-peptide radioimmunoassay with the synthetized connecting peptide by Yanaihara was tested for the determination of serum C-peptide immunoreactivity (CPR) in normal people and in diabetics with or without insulin treatment. The CPR value obtained by this method was not interfered with by the presence of serum proteins or by the insulin of people with or without insulin treatment judged by the dilution test and the recovery test. The normal fasting CPR was 2.80 +- 0.78 ng/ml with the synthetized C-peptide as a standard. The CPR value increased and reached a maximum 90 minutes after the ingestion of 50 g of glucose. The increase after the glucose loading reduced corresponding to the severity of diabetes, and some juvenile-onset diabetes showed no response. Adult-type diabetics under insulin treatment, however, showed weak but significant CPR response. The increment of CPR and immunoreactive insulin after glucose loading in normal people and non-treated diabetics was well correlated (γ=0.8262). Judged from the above mentioned results, CPR determination in insulin-treated diabetics was thought to be a useful method for the assessment of the insulin-secreting ability of beta-cells of the pancreas. (J.P.N.)

  7. Study on the C-peptide radioimmunoassay with synthetized connecting peptide

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    Nakagawa, S; Sasaki, T; Nakayama, H; Watanabe, T; Aoki, S [Hokkaido Univ., Sapporo (Japan). School of Medicine

    1976-01-01

    A method of C-peptide radioimmunoassay with the synthetized connecting peptide by Yanaihara was tested for the determination of serum C-peptide immunoreactivity (CPR) in normal people and in diabetics with or without insulin treatment. The CPR value obtained by this method was not interfered with by the presence of serum proteins or by the insulin of people with or without insulin treatment judged by the dilution test and the recovery test. The normal fasting CPR was 2.80 +- 0.78 ng/ml with the synthetized C-peptide as a standard. The CPR value increased and reached a maximum 90 minutes after the ingestion of 50 g of glucose. The increase after the glucose loading reduced corresponding to the severity of diabetes, and some juvenile-onset diabetes showed no response. Adult-type diabetics under insulin treatment, however, showed weak but significant CPR response. The increment of CPR and immunoreactive insulin after glucose loading in normal people and non-treated diabetics was well correlated (..gamma..=0.8262). Judged from the above mentioned results, CPR determination in insulin-treated diabetics was thought to be a useful method for the assessment of the insulin-secreting ability of beta-cells of the pancreas.

  8. Diagnostic value of C-peptide determination

    International Nuclear Information System (INIS)

    Kober, G.; Rainer, O.H.

    1983-01-01

    C-peptide and insulin serum determinations were performed in 94 glucagon-stimulated diabetics and in 15 healthy persons. A minimal increase of 1.5 ng C-peptide/ml serum after glucagon injection (1 mg i.v.) was found to be a useful parameter for the differentiation of insulin dependent and non-insulin dependent diabetics. The maximal response to glucagon occurred during the first 10-minutes after the injection (blood was drawn at 2-minutes intervals). Serum insulin levels and basal C-peptide concentrations were of no value in predicting insulin-dependency. Basal C-peptide levels were significantly different from control in juvenile insulin dependent diabetics (decrease) only. (Author)

  9. Radioimmunoassay of seric C-peptide. Practical value in the study of insulin secretion. Results of 140 stimulation tests

    International Nuclear Information System (INIS)

    Wafflart, Jean.

    1977-10-01

    C-peptide, which appears as a by-product of insulin synthesis, is secreted with this latter in equimolar quantities but is not degraded in the liver. It thus reflects indirectly the insulin secreted. After the structure of C-peptide was determined in 1971 by OYER it was synthesized by YANAIHARA and a radioimmunoassay was developed by KANEKO in 1974. This work was made possible by the recent commercialisation of a Japanese analysis kit, the 'DAIICHI' kit, and its availability through GUERBET TESTS. Part one describes the structural, physiological and immuno properties of C-peptide and its method of determination. Part two is devoted to a review of foreign publications on the practical interest of the C-peptide measurement. Part three gives the results of 140 oral or venous stimulation tests where blood sugar, blood insulin and C-peptide are measured in parallel. The different diabetic pathologies are explored and compared against normal subjects. The purpose of this work is to establish the value of C-peptide as a reflection of insulin secretion on the one hand, and that of a parallel insulin and C-peptide determination on the other [fr

  10. Optimization of reagent concentration for radioiodination of rat C-peptide II in development of radioimmunoassay procedure for rats

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    B R Manupriya

    2018-01-01

    Full Text Available Rat C-peptide is a polypeptide molecule made up of 31 amino acids and secreted from pancreas into circulation in two isoforms I and II. Quantification of rat C-peptide II in rat serum is important as it is directly related to the diagnosis of carbohydrate metabolism abnormalities, pancreatic performance analysis, monitoring of hypoglycemia, and diabetes-related illness in rat model. The aim of the present work is to develop a tracer by chloramine-T method for radioimmunoassay (RIA procedure and to determine the optimum amount of chloramine-T required for the preparation of stable radioiodinated product with a specific activity of around 24.97 MBq/μg, corresponding to 1 125I atom per molecule of the peptide. Tyrosylated rat C-peptide II was selected for the radioiodination procedure as rat C-peptide II does not contain either tyrosine or histidine which is mandatory for the incorporation of 125I atom to the rat C-peptide II. Tyrosylated rat C-peptide II was subjected to radioiodination by chloramine-T method with different concentrations of chloramine-T and sodium metabisulfite (MBS to obtain a stable radiolabeled compound. Optimized reaction conditions relating to the concentration of chloramine-T (10 μg and MBS (20 μg yielded a stable 125I-rat C-peptide II with specific activity of 21.01 MBq/μg corresponding to 0.84 125I atoms per molecule of the peptide. Preparation of high integrity tracer of rat C-peptide II was achieved by combining one molecule of oxidant (chloramine-T and two molecule of reductant (MBS.

  11. C-peptide comparative radioimmunoassays: a study of three commercial kits

    International Nuclear Information System (INIS)

    Villaume, C.; Beck, B.

    1983-01-01

    Plasma C-peptide immunoreactivity (CPR) was measured in 18 fasting subjects with three different commercial kits (RIA-mat C-peptide-, Byk-Mallinckrodt; RIA-gnost-hC-peptide, Hoechst-Behring; human C-peptide radioimmunoassay kit, Novo) The subjects were chosen as to cover a wide range of CPR concentrations (five healthy subjects, six obese subjects, three insulin-dependent diabetics, four normal subjects whose plasmas had been kept at - 20 0 C for periods of 16 or 36 months). CPR was measured with the Novo kit in eight other plasmas which were kept over a period of 36 months, with or without aprotinin. Good correlations have been established among the values found with the three kits. However, absolute concentration values for each subject as well as the dispersion of all plasma C-peptide values varied as a function of the kit used because of antibody specificity differences and because of the various separation methods. The normal range proposed changes with each kit and the blood CPR of a subject can be a normal, reduced or increased one, depending on the kit used. After several months of storage, plasma CPR degradation is observed with the three kits. A protease-inhibitor is necessary in order to avoid this C-peptide degradation due to the apparent existence of a plasma proteolytic enzyme

  12. Fundamental studies on the development of C-peptide radioimmunoassay kit

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    Nakazawa, N; Maki, K; Ogawa, H; Ikeda, O [Daiichi Radioisotope Labs. Ltd., Tokyo (Japan)

    1976-05-01

    We have studied the development of the C-peptide radioimmunoassay kit which is usable in the pancreatic function test with satisfactory results. The C-peptide antiserum was prepared by immunizing rabbits with synthetic human connecting peptide. The antiserum revealed no cross reaction with any C-peptides other than human C-peptide, porcine insulin and gastrointestinal hormone, and showed high specificity to human C-peptide. We adopted the double antibody method in B,F separation, and chose 4/sup 0/C, 48 hrs. for 1st. incubation and 4/sup 0/C, 24 hrs. for 2nd. incubation. On this kit, the assay range was 0.5 ng/ml-30 ng/ml, the recovery rate was 98.4%-107.8% in the recovery test, the coefficient of variance was 6.2% in the intra assay and was 7.6% in the inter assay. We think this kit is sufficiently usable to assay C-peptide in blood.

  13. Fundamental studies on the development of C-peptide radioimmunoassay kit

    International Nuclear Information System (INIS)

    Nakazawa, Nobuhiko; Maki, Kentaro; Ogawa, Hiroshi; Ikeda, Osamu

    1976-01-01

    We have studied the development of the C-peptide radioimmunoassay kit which is usable in the pancreatic function test with satisfactory results. The C-peptide antiserum was prepared by immunizing rabbits with synthetic human connecting peptide. The antiserum revealed no cross reaction with any C-peptides other than human C-peptide, porcine insulin and gastrointestinal hormone, and showed high specificity to human C-peptide. We adopted the double antibody method in B,F separation, and chose 4 0 C, 48 hrs. for 1st. incubation and 4 0 C, 24 hrs. for 2nd. incubation. On this kit, the assay range was 0.5 ng/ml-30 ng/ml, the recovery rate was 98.4%-107.8% in the recovery test, the coefficient of variance was 6.2% in the intra assay and was 7.6% in the inter assay. We think this kit is sufficiently usable to assay C-peptide in blood. (auth.)

  14. Clinical significance of determination of serum C-peptide levels

    International Nuclear Information System (INIS)

    Wang Guohong; Xu Ruiji; Zhang Zhongshu; Wang Xiaoji

    2006-01-01

    Objective: To study the clinical meanings of changes of serum C-peptide levels and insulin/C-peptide ratio. Methods: Serum insulin and C-peptide levels were determined with RIA in 171 patients with DM-2 of all ages (31-50, n= 50, 51-60, n=60, over 60, n=61) and 50 patients with renal insufficiency. The insulin/C-peptide ratio were calculated. Results: The serum C-peptide and insulin levels in patients with renal insufficiency were significantly higher than those in diabetics of all age groups and the insulin/C-peptide ratio were significantly lower than those in diabetics (P 0.05), but the serum C-peptide levels increased as the age of patients increased with decrease of insulin/C-peptide ratio (P<0.01). Conclusion: Abnormal changes of C-peptide levels and insulin/C-peptide ratio in diabetics (the age-factor corrected) might reflect renal dysfunction. (authors)

  15. Clinical significance of the radioimmunological determination of C-peptide

    International Nuclear Information System (INIS)

    Dudczak, R.; Waldhaeusl, W.

    1979-01-01

    The aim of this study was to investigate the relationship of metabolic control to insulinogenic reserve in insulin-dependent diabetics. Thus, the secretory reserve of the pancreatic beta cell was estimated in insulin-dependent diabetics by measuring changes in peripheral serum immunoreactive C-peptide (IRCP) concentrations in response to intravenous arginine (n = 19; 0.5 g/kg,t = 30 min) or glibenclamide-glucose (n = 6; 2 mg HB 419 - 0.33 g/kg intravenously). In the majority of ''stable'' diabetics a small secretory reserve of the beta cell was demonstrated, but both the absolute and relative increase in IRCP was reduced after intravenous arginine or glibenclamide-glucose in comparison with normal controls. In ''unstable'' diabetics a decreased basal concentration of IRCP, significantly smaller than that seen in ''stable'' diabetics (p < 0.01), was accompanied by a complete lack of IRCP release on intravenous arginine administration. Thus, we conclude that the radioimmunological determination of IRCP is of clinical interest in assessing the residual secretory capacity of the beta cell in insulin-dependent diabetics. In revealing a lack of insulin this diagnostic tool seems to detect a group of potentially ''unstable'' diabetics in need of strict observation, which would minimize the risks of bad metabolic control. (author)

  16. Clinical significance of the radioimmunological determination of C-peptide

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    Dudczak, R; Waldhaeusl, W [Vienna Univ. (Austria). 1. Medizinische Klinik

    1979-10-12

    The aim of this study was to investigate the relationship of metabolic control to insulinogenic reserve in insulin-dependent diabetics. Thus, the secretory reserve of the pancreatic beta cell was estimated in insulin-dependent diabetics by measuring changes in peripheral serum immunoreactive C-peptide (IRCP) concentrations in response to intravenous arginine (n = 19; 0.5 g/kg,t = 30 min) or glibenclamide-glucose (n = 6; 2 mg HB 419 - 0.33 g/kg intravenously). In the majority of stable diabetics a small secretory reserve of the beta cell was demonstrated, but both the absolute and relative increase in IRCP was reduced after intravenous arginine or glibenclamide-glucose in comparison with normal controls. In unstable diabetics a decreased basal concentration of IRCP, significantly smaller than that seen in stable diabetics (p < 0.01), was accompanied by a complete lack of IRCP release on intravenous arginine administration. Thus, we conclude that the radioimmunological determination of IRCP is of clinical interest in assessing the residual secretory capacity of the beta cell in insulin-dependent diabetics. In revealing a lack of insulin this diagnostic tool seems to detect a group of potentially unstable diabetics in need of strict observation, which would minimize the risks of bad metabolic control.

  17. Cross-validation of commercial enzyme-linked immunosorbent assay and radioimmunoassay for porcine C-peptide concentration measurements in non-human primate serum.

    Science.gov (United States)

    Gresch, Sarah C; Mutch, Lucas A; Janecek, Jody L; Hegstad-Davies, Rebecca L; Graham, Melanie L

    2017-09-01

    C-peptide concentration is widely used as a marker of insulin secretion and is especially relevant in evaluating islet graft function following transplantation, because its measurement is not confounded by the presence of exogenous insulin. To address the shortage of human islet donors, the use of porcine islets has been proposed as a possible solution and the stringent pig-to-non-human primate (NHP) model is often the most relevant for pre-clinical evaluation of the potential for diabetes reversal resulting from an islet xenograft. The Millipore radioimmunoassay (RIA) was exclusively used to measure porcine C-peptide (PCP) until 2013 when the assay was discontinued and subsequently a commercially available enzyme-linked immunosorbent assay (ELISA) from Mercodia has been widely adopted. Both assays have been used in pre-clinical trials evaluating the therapeutic potential of xenograft products in reversing diabetes in the pig-to-NHP model, to interpret data in a comparable way it may be useful to perform a harmonization of C-peptide measurements. We performed a method comparison by determining the PCP concentration in 620 serum samples collected from 20 diabetic cynomolgus macaques transplanted with adult porcine islets. All analyses were performed according to manufacturer instructions. With both assays, we demonstrated an acceptable detection limit, precision, and recovery. Linearity of the ELISA met acceptance criteria at all concentrations tested while linearity of the RIA only met acceptance criteria at five of the eight concentrations tested. The RIA had a detection limit of 0.16 ng/mL, and recovery ranged from 82% to 96% and met linearity acceptance criteria at 0.35 ng/mL and from 0.78 to 2.33 ng/mL. The ELISA had a detection limit of 0.03 ng/mL, and recovery ranged from 81% to 115% and met linearity acceptance criteria from 0.08 to 0.85 ng/mL. Both assays had intra-assay precision assay precision ELISA demonstrated a significant correlation with RIA (R

  18. Determination of phenobarbital by radioimmunoassay

    International Nuclear Information System (INIS)

    Yamaoka, A.; Takatori, T.

    1979-01-01

    A radioimmunoassay for phenobarbital has been studied. Antiphenobarbital antisera were obtained by repeated immunization of rabbits with p-succinamidophenobarbital conjugated to bovine serum albumin. Less than 0.2 pmol of phenobarbital could be measured by this procedure. The specificity of the antibodies was directed to substituents on the nitrogen atoms of the barbituric rings as well as to substituents at the carbon 5-position of the ring. (Auth.)

  19. Characterization of an insulin-like growth factor-I/somatomedin-C radioimmunoassay specific for the C-peptide region

    International Nuclear Information System (INIS)

    Hintz, R.L.; Liu, F.; Seegan, G.

    1982-01-01

    Insulin-like growth factor-I (IGF-I) and somatomedin-C (SM-C) have been shown to be functionally identical by a number of criteria. We have synthesized the 12 amino acid C-peptide region of IGF-I (Gly-Tyr-Gly-Ser-Ser-Ser-Arg-Arg-Ala-Pro-Glu-Thr) and developed a RIA based on antibodies against this synthetic peptide. IGF-I and SM-C were indistinguishable in this RIA. No other peptides competed for this antiserum. The SM-C/IGF-I values of acid-chromatographed serum were strongly age dependent. The mean of children 1-5 yr old was 0.67 +/- 0.033 U/ml (mean +/- sD; n = 23), whereas the mean of children 12-17 yr old was 2.01 +/- 0.66 U/ml (n = 39) and the mean of 38 adults 26-85 yr old was 1.05 +/- 0.34. The SM-C/IGF-I values measured by this RIA were also growth hormone dependent. Thus, this region-specific RIA provides a clinically useful assessment of serum SM-C/IGF-I levels

  20. Human c-peptide immunoreactivity (CPR) in blood and urine - evaluation of a radioimmunoassay method and its clinical applications

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    Kuzuya, T; Matsuda, A; Saito, T; Yoshida, S

    1976-01-01

    A double-antibody radioimmunoassay method, using synthetic human connecting peptide as an immunizing antigen and standard, was evaluated for clinical assay of blood and urine samples. Normal fasting blood connecting peptide immunoreacivity (CPR) was 2.45 +- 0.96 ng/ml, increasing promptly after a 50 g oral glucose load, but somewhat slower than insulin. Molar concentration of CPR exceeded that of insulin. CPR responses to glucose were subnormal in diabetics, very low in juvenile-type cases, and often poor in patients on insulin treatment. Fasting CPR levels were elevated in patients on corticosteroid treatment and with uraemia. A patient with insulin 'auto-antibody' had high serum CPR. A considerable amount of CPR appeared in urine. Normal daily excretion of CPR was 1.52 +- 0.55 ..mu..g/kg or 55.1 +- 18.2 ng/mg creatinine. Urine CPR was very low in juvenile-type diabetics, and elevated in patients on corticosteroid treatment. The results confirm that blood and urine CPR are useful measures of the endocrine pancreatic function.

  1. Determination of serum IgD radioimmunoassay

    International Nuclear Information System (INIS)

    Fayol, V.; Hartmann, D.J.; Sabbagh, I.; Ville, G.

    1986-01-01

    We describe a sensitive liquid phase radioimmunoassay for serum IgD. Extreme values obtained from 85 control patients sera are 0.2 and 121 mg/l with an arithmetic mean of 25 mg/l. In atopic patients (with high serum IgE levels), arithmetic mean is 47 mg/l [fr

  2. Determination of serum IgD radioimmunoassay

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    Fayol, V.; Hartmann, D.J.; Sabbagh, I.; Ville, G.

    1986-01-01

    We describe a sensitive liquid phase radioimmunoassay for serum IgD. Extreme values obtained from 85 control patients sera are 0.2 and 121 mg/l with an arithmetic mean of 25 mg/l. In atopic patients (with high serum IgE levels), arithmetic mean is 47 mg/l.

  3. Qualitative determination of tubulin by radioimmunoassay

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    Joniau, M [Louvain Univ. (Belgium). Interdisciplinary Research Centre; Brabander, M de [Janssen Pharmaceutica, Beerse (Belgium). Lab. of Oncology; Mey, J de [Brussels Univ. (Belgium). Medische Stichting Koningin Elisabeth; Hoebeke, J [Brussels Univ. (Belgium). Lab. of Biochemical Pathology

    1977-06-15

    The use of an antiserum specific for tubulin in cytochemical studies was described previously. Here a report is presented on its application in a radioimmunoassay for tubulin useful in the concentration range of 0.5 to 20 ..mu..g tubulin/ml. The advantages of this technique over the classical colchicine binding assay are discussed in terms of sensitivity and nonsusceptibility to the degree of polymerization and thermal denaturation of tubulin allowing its application to cell culture homogenates.

  4. Determination of carbofuran in water by radioimmunoassay

    International Nuclear Information System (INIS)

    Zhu Guonian; Wu Huiming; Yang Ting; Hu Xiuqing

    2004-01-01

    A competitive radioimmunoassay (RIA) method was established to detect carbofuran in water samples. Compared with traditional analytical methods RIA provided a easy procedure with higher sensitivity. The detective limitation of RIA for carbofuran was proved to be 0.175 ng/ml. A study was performed to test validation of the RIA. In this study carbofuran residues in water samples were detected simultaneously by RIA and by high performance liquid chromatograph (HPLC). The linear correlation coefficient of the test results was measure to be 0.9985. (authors)

  5. Human C-peptide. Pt. 1

    International Nuclear Information System (INIS)

    Beischer, W.; Keller, L.; Maas, M.; Schiefer, E.; Pfeiffer, E.F.

    1976-01-01

    Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with 125 iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum. (orig.) [de

  6. Determination of triiodothyronine in serum by enzyme- and radioimmunoassay

    International Nuclear Information System (INIS)

    Oellerich, M.; Haindl, H.; Medizinische Hochschule Hannover

    1981-01-01

    An evaluation of a heterogeneous enzyme immunoassay for determination of triiodothyronine in serum (Enzymun-Test T 3 , Boehringer Mannheim) is presented. The enzyme immunoassay was compared with the laboratory routine radioimmunoassay. The precision of both assays was satisfactory at triiodothyronine concentrations between 1.0 and 8.0 nmol/l (coefficients of variation from day to day 3 from 96-104% and with the radioimmunoassay from 88-111%. A comparison of the results obtained by Enzymun-Test T 3 and the radioimmunoassay in a series of 103 patients showed a good correlation between both methods. L-thyroxine did not cause a relevant cross-reaction in the enzyme immunoassay. About 20 unknown samples can be analyzed in triplicate by Enzymun-Test T 3 within 260 minutes. (orig.) [de

  7. Determination of plasma oxytocin by radioimmunoassay

    International Nuclear Information System (INIS)

    Ogawa, Satsuki; Fukuchi, Soitsu; Miura, Tadashi

    1978-01-01

    A simple radioimmunoassay was applied to the measurement of oxytocin in human plasma. A high specificity of immunoassay was demonstrated by the fact that large excess of angiotensin I and II, and ACTH did not displace labelled oxytocin from the antibody. Lysine-8-vasopressin and arginine-8-vasopressin showed very little cross-reaction in the assay, possessing only 0.002% of the immunological potency of oxytocin. The specific activity of 125 I-oxytocin was 166 μCi/μg. Adsorption and extraction capacities of Florisil were 96.6 +- 2.1% and 85.7 +- 2.5%, respectively. Intra- and inter-assay variability were 7.2 +- 4.9% and 4.3 +- 2.2%, respectively. The sensitivity of the assay was below 1 pg/tube. Normal levels of plasma oxytocin were 0 - 2.2 pg/ml (n=13) in males and 0 - 10.4 pg/ml (n=10) in females. Plasma oxytocin levels in the 39th and 40th weeks of pregnancy were 27.9 +- 4.14 pg/ml (n=4) and 29.8 +- 17.1 pg/ml (n=13), respectively. The levels increased to 33.1 +- 12.1 pg/ml (n=7) and 37.1 +- 17.5 pg/ml (n=7) in the first and third stages of labor, and decreased to 13.6 +- 5.25 pg/ml (n=6) on the 2nd to 8th day after labor. The radioimmunoassay for oxytocin in plasma is considered to be sufficiently applicable for clinical use. (auth.)

  8. Direct salivary cortisol radio-immunoassay determination. Clinical applications

    International Nuclear Information System (INIS)

    Simon, C.; Cherfan, J.; Kurtz, F.; Vignon, F.; Schlienger, J.L.; Chabrier, G.

    1987-01-01

    Salivary cortisol levels reflect the biologically active free fraction of blood cortisol. The authors describe the results obtained with the aim of a radio-immunoassay commercial serum cortisol kit, without prealable extraction in different physiological and pathological situations. Salivary cortisol determination appears performant both in nycthemeral studies and in stimulation or freination tests [fr

  9. Determination of digoxin by enzyme immunoassay and radioimmunoassay

    International Nuclear Information System (INIS)

    Mueller, H.; Braeuer, H.; Foerster, G.; Reinhardt, M.

    1978-01-01

    The results of parallel determinations of digoxin in the sera of non selected patients (n=104) by enzyme immunoassay (EMIT.EIA) and radioimmunoassay (J-125 labeled RIA) were compared with each other. The determinations revealed considerably different concentrations; the values determined by EIA were statistical lower (for EIA 1,09+'0,99ng/ml, for RIA 1,34+'1,01ng/ml, p [de

  10. Radioimmunoassay for determination of the hormonal and immune states in patients aczema; psoriasis and neurodermatitis

    International Nuclear Information System (INIS)

    Baltabaev, T.S.

    1989-01-01

    The hormonal and immune status was investigated by a radioimmunoassay in 105 patiets with dermatosis (55 female and 50 male patients aged 15 to 80): 51 suffered frm ecsema, 41 -from psoriasis, and 13 - from neurodermatitis. Serum concentrations of T 3 , T 4 , TSH, insulin, trypsin, C-peptide, cortisol, and IgE were investigated. Disorders of the hormonal and immune status were noted in the examinees with relation to sez, type of disease, season, time-period and extent of disease

  11. Oxytocin determination by radioimmunoassay in cattle. 1

    International Nuclear Information System (INIS)

    Schams, D.; Schmidt-Polex, B.; Kruse, V.

    1979-01-01

    A radioimmunoassay for oxytocin in cow plasma is described. Antisera were raised in rabbits against synthetic oxytocin coupled to bovine thyroglobulin. Iodinated oxytocin free of unlabelled oxytocin and most likely also free of diiodo-oxytocin was used as radioactive tracer. The tracer showed a high degree of purity, and was stable on storage. It could be used in the assay for 2-3 months. The assay showed very little cross-reactivity with vasopressin. Acetone was used for the extraction of oxytocin from plasma as well as from standards made of synthetic exytocin in pooled cow plasma. Inhibition curves obtained with plasma collected from cows at parturition were parallel to those obtained with the oxytocin standard preparation. The mean recovery of oxytocin added to cow plasma was 106% (SD=14). The within-assay coefficient of variation (CV) varied from 5.2 to 10.9%, and the between-assay CV was in the order of 13%. The assay sensitivity was 1 pg (0.5 μU) per tube, corresponding to 3 pg/ml plasma. Around the time of milking the plasma oxytocin profile showed a strong response to the preparation for milking, and a further effect related to the attachment of the teat cups of the milking machine. Peak concentrations were in the range of 15-50 pg/ml. During parturition there was a peak of oxytocin (65 pg/ml) coinciding with the expulsion phase. After this peak levels decreased by remained measurably elevated until the expulsion of the placenta. The plasma disappearance curve for immunoreactive oxutocin after the infusion of 100 IU oxytocin over a period of 1 h showed two components with apparent half-lives of 7-9 and 25 min, respectively. (author)

  12. Method of insulin determination by radioimmunoassay technique

    Energy Technology Data Exchange (ETDEWEB)

    Kokot, F; Kuska, J [Slaska Akademia Medyczna, Katowice (Poland)

    1973-01-01

    Technical details of a radioimmunological method of insulin determination in blood serum have been presented. Clinical value of the method was checked in 31 healthy subjects following oral or intravenous glucose administration, or after pancreatic islet stimulation using tolbutamide.

  13. Determination of hormone parathyroid by radioimmunoassay

    International Nuclear Information System (INIS)

    Fisher-Ferraro, Catalina; Moos de Ephraim, Monica; Mautalen, Carlos; Mitta, A.E.A.

    1978-10-01

    The labelling of bovine parathyroid hormone and its employment for the determination of seric PTH by radioimmunoanalysis is described. The specific activity of 131 I PTH is 200-350mCi/mg and the damage 3-5%. The method used for radioimmunoanalysis was that of C.D. Arnaud and coworkers. (author) [es

  14. Insulin C-peptide test

    Science.gov (United States)

    C-peptide ... the test depends on the reason for the C-peptide measurement. Ask your health care provider if ... C-peptide is measured to tell the difference between insulin the body produces and insulin someone injects ...

  15. Radioimmunoassay for determination of thyroglobulin in human serum

    International Nuclear Information System (INIS)

    Rodriguez Cabrera, M.E.; Blanca Fernandez, S.; Baldor Navarro, F.; Rodriguez Gonzalez, J.C.

    1996-01-01

    We described the development and analytical evaluation of a radioimmunoassay with double antibody in liquid phase for human serum thyroglobulin determination using a set of reagents produced in the National Institute of Endocrinology. The reference interval for normal population was 5.7 - 44 ng/ml (X± 2DS; n=170). The intra-assay precipision was 8.1 % (control serum A) and 7.0 (control serum B) and the inter-assay precision was 9.1 % (control serum A) and 9.2 % (control serum B). The sensibility was 4.7 ng/ml and the recovery was 95 %

  16. Intrinsic factor in human amniotic fluid as determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Wahlstedt, V.; Stenman, U.-H.; Ylinen, K.; Graesbeck, R.

    1983-01-01

    The intrinsic factor (IF) concentration in 55 human amniotic fluid specimens was determined by radioimmunoassay (RIA). The antiserum was produced by immunizing rabbits with the cobalamin-IF complex isolated from human gastric juice. The median concentration of IF was 0.17 nmol/l and the extreme values <0.07-2.51 nmol/l. Three specimens with a clearly elevated level (0.96, 1.11 and 2.51 nmol/l) were observed. The highest value was associated with a fetal malformation, viz. obstruction of the proximal gut. There was no evident correlation between the concentration of IF in amniotic fluid and gestational age. (author)

  17. Pancreatic elastase in human serum. Determination by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Geokas, M.C. (Univ. of California, Davis); Brodrick, J.W.; Johnson, J.H.; Largman, C.

    1977-01-10

    This study demonstrates that a serine endopeptidase of pancreatic origin (elastase 2) circulates in human blood. A specific and highly sensitive radioimmunoassay has been developed for pancreatic elastase 2 in human serum. The inactivation of elastase 2 employed as radioiodinated tracer with an active site-specific reagent (phenylmethanesulfonyl fluoride) was necessary to prevent its binding by serum ..cap alpha../sub 1/-antitrypsin and ..cap alpha../sub 2/-macroglobulin while maintaining its immunoreactivity. The assay is based upon competition of standard human pancreatic elastase 2 with /sup 125/I-labeled phenylmethanesulfonyl elastase 2 for specific antibody binding sites, after which a second antibody precipitation step is used to separate bound from free /sup 125/I-labeled phenylmethanesulfonyl elastase 2. The minimum detectable concentration of elastase 2 was 0.9 ng/ml. The average normal fasting serum level determined was 71 ng/ml, approximately 80-fold greater than the minimum detectable amount.

  18. Comparison of commercially available radioimmunoassays for the determination of bile acids in serum

    Energy Technology Data Exchange (ETDEWEB)

    Wildgrube, H.J.; Schiller, W.; Winkler, M.; Weber, J.; Campana, H.; Mauritz, G.

    1982-05-01

    Three commercially available radioimmunoassays for the determination of bile acids in serum were evaluated with respect to specificity and precision. The SLCG-radioimmunoassay (Abbott) measures only sulphated glycolithocholic acid, the CG-radioimmunoassay (Abbott) measures chiefly cholic acid conjugates, and the CBA-radioimmunoassay (Becton-Dickinson) measures all conjugated bile acids, with an over-response to taurine metabolites. With respect to cross reactions, the performances of the CG-and the CBA-radioimmunoassays differed significantly from those stated by the manufacturers, the former showing a 32% response to taurocholic acid, the latter responding only 118% to taurochenodeoxycholic acid. At physiological concentrations of albumin + globulin, the recovery of defined cholanic acids was 85-101%. Good reproducibility was shown by the CG-radioimmunoassay in the range 0.5-10.9 ..mu..mol/l, by the CBA-radioimmunoassay in the range 1.0-25.0 ..mu..mol/l, and by the SLCG-radioimmunoassay in the range 0.5-3.0 ..mu..mol/l. There were no important differences in the inter- and intra-assay precision of the three methods.

  19. Comparative studies on the determination of alphafetoprotein by enzyme immunoassay and by radioimmunoassay

    International Nuclear Information System (INIS)

    Haller, G.; Linneke, P.; Voss, P.; Jeske, W.

    1987-01-01

    Alphafetoprotein (AFP) was determined in serum of pregnant women in the tenth till sixteenth week of pregnancy by means of two enzyme immunoassays (Enzymun-Test AFP, Boehringer Mannheim, FRG and AFP EIA 'Dessau' 1000, Research Institute for Vaccine Dessau, GDR) and a radioimmunoassay (Radioimmunoassay Kit, AFP-PR, CIS, France). Parallel determinations in sera of 438 patients, who had come to surveillance for the first consultation were estimated. A comparison between the methods showed a good correlation. (author)

  20. Determination of antithrombin III by radioimmunoassay and its clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Chan, V; Chan, T K; Wong, V; Tso, S G; Todd, D [Queen Mary Hospital, Hong Kong

    1979-04-01

    A radioimmunoassay (RIA) has been developed for the determination of antithrombin III (AT III) in man. The detection limit was 25 ..mu..g/dl. At III-RIA level and biological activity (anti-Xa) was significantly correlated (r = 0.737, P < 0.0001). Plasma levels in 36 healthy males (mean +- SD, 19.9 +- 2.5 mg/dl) and 21 healthy females (19.1 +- 2.4 mg/dl) were similiar. Serial AT III measurements in normal menstruating females showed lower levels during midcycle and higher concentrations during menstruation. In carcinomas, the AT III levels were lower than normal, particularly in hepatocellular carcinoma. In cirrhosis of liver, the levels were markedly decreased and in some patients were below that found in congenital AT III deficiency. Patients with deep vein thrombosis and patients with heart valve replacement had lower levels than normal, while patients with cerebral vascular occlusion had normal levels. The possible use of AT III as a diagnostic tool of post-operative deep vein thrombosis was demonstrated in one patient after hysterectomy. The increased sensitivity, specificity and precision of this type of assay offer distinct advantages over existing methods of AT III estimation.

  1. Automatic computation of radioimmunoassay data

    International Nuclear Information System (INIS)

    Toyota, Takayoshi; Kudo, Mikihiko; Abe, Kanji; Kawamata, Fumiaki; Uehata, Shigeru.

    1975-01-01

    Radioimmunoassay provided dose response curves which showed linearity by the use of logistic transformation (Rodbard). This transformation which was applicable to radioimmunoassay should be useful for the computer processing of insulin and C-peptide assay. In the present studies, standard curves were analysed by testing the fit of analytic functions to radioimmunoassay of insulin and C-peptides. A program for use in combination with the double antibody technique was made by Dr. Kawamata. This approach was evidenced to be useful in order to allow automatic computation of data derived from the double antibody assays of insulin and C-peptides. Automatic corrected calculations of radioimmunoassay data of insulin was found to be satisfactory. (auth.)

  2. Determination of the range of control limits in radioimmunoassay measurements

    International Nuclear Information System (INIS)

    Fiori, A.M.C.

    1981-01-01

    A grouping technique is proposed for control limits in radioimmunoassay measurements. It has the advantage of working with control limits of 99.7% without the inconvenience of the confidence intervals. The method is practical and simple. It provides considerable flexibility for the processing of data. As the number of samples increases, the control limits become better defined. (author) [es

  3. Radioimmunoassay for determination of tumor markers in the diagnosis of rectal cancer recurrences

    International Nuclear Information System (INIS)

    Ozhiganov, E.L.; Kuznetsova, L.F.

    1991-01-01

    The levels of tumor markers were determined in patients with rectal cancer recurrences by radioimmunoassay. An increase in a CEA level was observed most frequently. An increase in the levels of α-fetoprotein, ferritin and β 2 -microglobulin was observed. It was shown that the most specific and effective diagnostic test of rectal cancer recurrences was the determination of a CEA level

  4. Radioimmunoassay for the determination of free and conjugated abscisic acid

    International Nuclear Information System (INIS)

    Weiler, E.W.

    1979-01-01

    The characterization and application of a radioimmunoassay specific for free and conjugated abscisic acid (ABA) is reported, The antibodies produced against a bovine serum albumin-(+-)-ABA conjugate have a high affinity for ABA (Ka= 1.3 x 10 9 l mol -1 ). Trans, trans-ABA and related compounds, such as xanthoxin, phaseic acid, dihydrophaseic acid, vomifoliol or violaxanthin do not interfere with the assay. The detection limit of this method is 0.25 x 10 -12 mol ABA, the measuring range extends to 20 x 10 -12 mol, and average recoveries are 103%. Because of the high specificity of this immunoassay, no extract purification steps are required prior to analysis. Several hundred plants can be analyzed per day in a semi-automatic assay performance. ABA has been detected in all higher plant families examined, but was absent in the blue-green alga, Spirulina platensis, the liverwort Marchantia polymorpha, and two species of fungi. (orig.) [de

  5. Radioimmunoassay of hair for determining opiate-abuse histories

    International Nuclear Information System (INIS)

    Baumgartner, A.M.; Jones, P.F.; Baumgartner, W.A.; Black, C.T.

    1979-01-01

    Heroin and morphine metabolites can be detected in hair with the use of commerically available radioimmunoassay reagents and with minor sample preparation. Hair samples obtained from morphine-treated mice and heroin users contained nanogram levels of the drug per milligram of hair (single human hair). The results of the hair analyses for all subjects admitting the use of heroin were positive, whereas the results of only 30% of thin-layer chromatographic urinanalyses of these same subjects were positive. In addition, differences in drug concentration for sections of hair near the scalp and near the distal end correlated with the length of time the drug had been used. These results exemplify the potential advantages of the use of hair analysis over urine and serum analyses in terms of accessibility, sample stability, and long-term retention of information

  6. Normal levels of plasma FSH and LH in the menstrual cycle as determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Lemgruber, I.; Pinto, J.C.M.; Linhares, E.; Granafer, A.

    1981-01-01

    The biological methods were not able to establish adequately the separate determination of FSH and LH. The introduction of radioimmunoassay had allowed the identification of plasma FSH and LH for the purpose of routine clinical use. The utilization of commercial kits, however, obliges each laboratory to have normal levels of his own. Such is the finality of this work, studying samples from 200 normal women, hospitalized for surgical reasons and having not any endocrinological problem. (author) [pt

  7. Antigenic relatedness of primate procollagens as determined by a competitive radioimmunoassay

    International Nuclear Information System (INIS)

    Taubman, M.B.; Goldberg, B.

    1978-01-01

    A radioimmunoassay specific for the nonhelical carboxy terminal portion of human type I procollagen was used to study the antigenic relatedness of primate procollagens. The assay identified reactive antigen in primate sera and in the media of primate fibroblast cultures. The displacement curves generated in the assay indicated that human and ape type I procollagens have antigenically identical carboxy terminal determinants which are partially cross-reactive with those from Old and New World monkeys. (author)

  8. Ovulation following gonadotrophin treatment and determination of serum estradiol and progesterone by radioimmunoassay

    International Nuclear Information System (INIS)

    Vesper, B.; Lisse, K.; Ittrich, G.

    1979-01-01

    The use of gonadotrophins to release ovulation is indicated in women with urgent desire for children and with negative response to clomiphene therapy. 69 patients treated with 100 therapeutic gonadotrophin series were examined. Estrogens and progesterone were determined by radioimmunoassay. The treatment resulted in ovulation in 54 women, 12 patients developed an ovarian reaction with an increase of estrogen, and in 34 cases no ovarian response was detectable. 6 women became pregnant during gonadotrophin therapy and further 2 after treatment

  9. Development and evaluation of the determination of the polyamines spermine and spermidine by radioimmunoassay

    International Nuclear Information System (INIS)

    Shaw, G.G.

    1985-08-01

    In 1975 Bartos et al described a radio-immunoassay for spermine which lacked specificity. In subsequent years the same group has reported the production of a specific antibody to spermidine and to spermine. The availability of specific antibodies potentially transformed the usefulness of radioimmunoassay from a system useful for semi-quantitative screening to one with a much broader applicability in the area of quantitative assay of polyamines. It was claimed that the assay would quantify as little as 10 picogrammes of spermidine or spermine. Up to 1982 when the present project commenced no other groups had reported using the Bartos assay. The present study was therefore indicated in order to determine whether specific antibodies could be produced in laboratories other than those of the Bartos group and to validate the assay by comparing it with the much more widely used and well established HPLC methods currently available

  10. Determination of degree of oncologic disease spreading with the use of radioimmunoassay

    International Nuclear Information System (INIS)

    Chebotareva, Eh.D.; Shishkina, V.V.; Korolev, V.I.; Sklyar, S.Yu.; Kukot', V.A.

    1989-01-01

    An effort to evaluate the possibility of applying tumor morkers to determine the degree of oncologic desease propagation is made. Radioimmunoassay of 431 patients with tumors with different localization is performed. In patients with lung, esophagus, stomach, rectum cancer the level of carcinoembryonic antigen (CEA) in the blood serum is studied, with mammary gland cancer - the CEA, ferritin and prolactin levels. An increase of CEA level is detected under wide-spread forms of lung, esophagus, stomach and rectum cancer, and an increase of CEA, ferritin and prolactin levels-under mammary gland cancer. It is shown that radioimmunoassay of tumor marker level is quite information content as to the evaluation of tumor process propagation under digestive tract, lung and mammary gland cancer. 12 refs.; 5 tabs

  11. Radioimmunoassay methods for the determination of L-triiodo-thyronine and thyroxine

    International Nuclear Information System (INIS)

    1976-01-01

    An improved, simplified radioimmunoassay method for the in vitro determination of L-triiodo-thyronine in unextracted blood serum is described which involves the use of a combination reagent constituted by a buffered solution containing radioactive L-triiodothyronine and an inhibitor for inhibiting the binding of L-triiodothyronine to thyroxine-binding globulin. Optionally the reagent may also include an antiserum containing an antibody capable of immunoreactivity with L-triiodothyronine. Packaged test kits for use in conveniently carrying out the radioimmunoassay are also provided. Certain salts of 8-anilino-1-naphtalene sulfonic acid, which may be regarded as purified forms of the acid, are preferably employed as inhibitors for inhibiting binding of L-triiodothyronine to thyroxine-binding globulin

  12. Connecting peptide (c-peptide) and the duration of diabetes mellitus ...

    African Journals Online (AJOL)

    Objective: C-peptide is derived from proinsulin and it is secreted in equimolar concentration with insulin. Plasma C-peptide is more stable than insulin and it provides an indirect measure of insulin secretory reserve and beta cell function. To determine relationship between C-peptide and duration of diabetes mellitus, age, ...

  13. Radioimmunoassay method for the determination of cardiotonic glycosides

    International Nuclear Information System (INIS)

    1975-01-01

    A kit method for the in vitro determination of digoxin and digitoxin is described. The blood serum is mixed with the reagent which consists of an aqueous buffer solution containing a radiolabeled hapten for the glycoside. Antiserum with specific antibodies is added and the mixture is incubated. Thereafter, a thin strip of membrane mainly consisting of an ionexchanger is brought into contact with the mixture to separate the antibody bound hapten from the unbound hapten. The ratios of both are determined by counting the radioactive hapten

  14. Determination of carcinoembryonic antigen: experiences with a new radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Lamerz, R [Univ., Munich; Ruider, H

    1976-04-01

    The determination of the carcinoembryonic antigen (CEA) as RIA-test was examined and tested. Labelling was carried out with /sup 125/I according to the chloramin T-method, as RIA in the form of a competitive double antibody examination. The method was tested on patients with colonic and pancreatic carcinomas.

  15. Prenatal sex determination by radioimmunoassay of testosterone with and without chromatography of the amniotic fluid

    International Nuclear Information System (INIS)

    Distler, W.; Boniver-Ollmann, U.; Tigges, J.; Terinde, R.; Claussen, U.

    1979-01-01

    Amniotic fluid testosterone measured by radioimmunoassay (RIA) without chromatography (immunoreactive testosterone) seems not to be a definitive test for prenatal sex determination in all cases. In this study testosterone (T) levels measured by RIA with chromatography of the amniotic fluid samples were compared with immunoreactive testosterone (iT) values, to determine the predictive accuracy of the two methods. In 111 amniotic fluid samples between 15 and 19 weeks of gestation iT and T were measured parallelly. There are significant differences between iT- and T-means of both sexes (p [de

  16. Results of the HPL determination using a new enzymatic immunoassay - comparison with a commercial radioimmunoassay

    International Nuclear Information System (INIS)

    Leis, D.; Schneider, B.; Keller, A.; Braun, S.

    1982-01-01

    An enzymatic immunoassay recently developed by the firm Organon, Oss, Netherlands, to determine HPL in the serum of pregnant women was compared to a widely used radioimmunoassay marketed by the firm Amersham-Buchler, Braunschweig. The values determined showed a good correlation. The accuracy of measurement was within the generally accepted range for immunological assays of this kind. The assay procedures are comparable with regard to the expenditure of time and work. A great advantage of the EIA is due to the absence of radioactive substances, which permits this test to be performed in any laboratory equipped with a centrifuge and photometer. (orig.) [de

  17. Radioimmunoassay compared to an enzymatic method for serum bile acid determination

    International Nuclear Information System (INIS)

    Samuelson, K.

    1980-01-01

    Radioimmunoassay (RIA) of cholic and chenodeoxycholic acid was compared to a total bile acid determination with 3α-hydroxysteroid dehydrogenase (3α HSD) and a gas liquid chromatographic (GLC) determination of individual bile acids. When sera from patients with increased bile acid concentration were analysed the results indicated a good correlation between GLC and the other methods. Analysis of sera from healthy subjects indicated a good correlation between GLC and RIA. No correlation existed between RIA and 3α-HSD when serum bile acids were analysed in healthy subjects partly due to the presence of varying amounts of secondary bile acids. (author)

  18. Standardization of the radioimmunoassay technique for the determination of human gastrin and its clinical application

    International Nuclear Information System (INIS)

    Peig Ginabredra, M.G.

    1989-01-01

    It was developed and standardized a system of radioimmunoassay for the determination of gastrin, employing synthetic human gastrin for radioiodination and preparation of standard as well as specific antibody raised rabbits. The hormone was labeled with 125 I by the Cloramine T techique and purified by anion exchange chromatography in QAE-Sephadex A-25, being determined its specific activity. The tracer thus obtained was submitted to analysis of purity by poliacrilamide gel eletrophoresis and precipitation of proteins by trichloroacetic acid. Its stability evaluated according to the time of storage, being its purity and adequation for the use in radioimmunoassay also compared to a tracer obtained from a commercial diagnosis kit. The assays were performed by incubation of radioiodinated gastrin, standard gastrin prepared in plasma free from this hormone (from zero to 500 pmol/l) or samples to be assayed with the antiserum for 4 days at 4 0 C. The separation between the free gastrin and the gastrin bound to the antibody was carried out by adsorption of the free hormone to the charcoal, whose ideal concentration was previously determined. Plasma free from gastrin was obtained from time-expired blood bank plasma submitted to extraction with charcoal. When performed the quality control, this radioimmunoassay was shown specific, accurate, precise and sensitive, allowing the performance of valid assays. Its validation was even confirmed by clear discrimination not only of the gastrin concentration in subjects with very low levels (gastrectomized) and extremely high levels (Zollinger-Ellison syndrome) as well as gastrin concentrations in subjects with other diseases, such as Chagas disease, pernicious anemia and chronic renal failure. (author) [pt

  19. Use of radioimmunoassay procedures for the determination of sex hormones in animal tissues

    International Nuclear Information System (INIS)

    Hoffmann, B.

    1983-01-01

    Radioimmunoassay methods for the determination of sex steroids and other compounds with sex hormone-like activities in various edible animal tissues and endocrine glands have been developed. Reliability of these methods, allowing quantification in a range of 10 -11 M, has been adequately demonstrated. When applied to monitoring residues of anabolic sex hormones in edible tissues of veal calves, physiological baseline levels of some endogenous ''anabolic'' steroids (like testosterone, oestrogens) were established; in the case of xenobiotics residues at the scheduled time of slaughter could be quantified (trenbolone) and a regulatory method to implement the ban of diethylstilbestrol was introduced. (author)

  20. Use of radioimmunoassay procedures for the determination of sex hormones in animal tissues

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, B. (Institut fuer Veterinaermedizin des Bundesgesundheitsamtes (Robert von Ostertag-Institut), Berlin (Germany, F.R.))

    1983-07-01

    Radioimmunoassay methods for the determination of sex steroids and other compounds with sex hormone-like activities in various edible animal tissues and endocrine glands have been developed. Reliability of these methods, allowing quantification in a range of 10/sup -11/ M, has been adequately demonstrated. When applied to monitoring residues of anabolic sex hormones in edible tissues of veal calves, physiological baseline levels of some endogenous ''anabolic'' steroids (like testosterone, oestrogens) were established; in the case of xenobiotics residues at the scheduled time of slaughter could be quantified (trenbolone) and a regulatory method to implement the ban of diethylstilbestrol was introduced.

  1.  Pleiotropic action of proinsulin C-peptid

    Directory of Open Access Journals (Sweden)

    Michał Usarek

    2012-03-01

    Full Text Available  Proinsulin C-peptide, released in equimolar amounts with insulin by pancreatic β cells, since its discovery in 1967 has been thought to be devoid of biological functions apart from correct insulin processing and formation of disulfide bonds between A and B chains. However, in the last two decades research has brought a substantial amount of data indicating a crucial role of C-peptide in regulating various processes in different types of cells and organs. C-peptide acts presumably via either G-protein-coupled receptor or directly inside the cell, after being internalized. However, a receptor binding this peptide has not been identified yet. This peptide ameliorates pathological changes induced by type 1 diabetes mellitus, including glomerular hyperfiltration, vessel endothelium inflammation and neuron demyelinization. In diabetic patients and diabetic animal models, C-peptide substitution in physiological doses improves the functional and structural properties of peripheral neurons and protects against hyperglycemia-induced apoptosis, promoting neuronal development, regeneration and cell survival. Moreover, it affects glycogen synthesis in skeletal muscles. In vitro C-peptide promotes disaggregation of insulin oligomers, thus enhancing its bioavailability and effects on metabolism. There are controversies concerning the biological action of C-peptide, particularly with respect to its effect on Na /K -ATPase activity. Surprisingly, the excess of circulating peptide associated with diabetes type 2 contributes to atherosclerosis development. In view of these observations, long-term, large-scale clinical investigations using C-peptide physiological doses need to be conducted in order to determine safety and health outcomes of long-term administration of C-peptide to diabetic patients.

  2. Production of peptide antisera specific for mouse and rat proinsulin C-peptide 2

    DEFF Research Database (Denmark)

    Blume, N; Madsen, O D; Kofod, Hans

    1990-01-01

    for antibody binding to the immunizing antigen. Antisera to C-peptide 2, stained islet beta-cells on mouse and rat, but not monkey pancreas sections in immunocytochemical analysis. Preabsorption to the synthetic C-peptide 2, but not the synthetic mouse and rat C-peptide 1 abolished staining. In conclusion we......Mice and rats have two functional non-allelic insulin genes. By using a synthetic peptide representing a common sequence in mouse and rat C-peptide 2 as antigen, we have produced rabbit antisera specific for an epitope which is not present in mouse or rat C-peptide 1. Long-term immunization did...... not seem to increase the end point titre as tested in direct ELISA. The specificity of the antiserum was determined by competitive ELISA and histochemistry on pancreas sections. Only the synthetic C-peptide 2, but not the homologous synthetic C-peptide 1 from mouse and rat competed efficiently in ELISA...

  3. Determination of a glucose-containing tetrasaccharide in urine by radioimmunoassay

    International Nuclear Information System (INIS)

    Zopf, D.A.; Levinson, R.E.; Lundblad, A.

    1982-01-01

    A radioimmunoassay is described that allows rapid determination of a urinary oligosaccharide - Glcα1-6Glcα1-4Glcα1-4Glc [(Glc) 4 ] - at concentrations >2pmol/μl. Antibodies produced in rabbits immunized with the phenethylamine derivative of (Glc) 4 coupled to keyhole limpet hemocyanin bind tritiated (Glc) 4 -alditol. Studies comparing the activities of (Glc) 4 and several of its derivatives and analogues as inhibitors of binding of tritiated (Glc) 4 -alditol show that (Glc) 4 is detected with maximum specificity and sensitivity only after reduction to (Glc) 4 -alditol. Quantitation of (Glc) 4 in urine samples reduced with sodium borohydride gives excellent agreement with a previously used but more laborious method that employs gas-liquid chromatography-mass spectrometry (GLC/MS) (correlation coefficient = 0.98). Studies of the excretion rate of (Glc) 4 in urine of women during pregnancy using the radioimmunoassay method confirm and extend previous results using the GLC/MS method. (Auth.)

  4. Determination of a glucose-containing tetrasaccharide in urine by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Zopf, D.A.; Levinson, R.E. (National Cancer Inst., Bethesda, MD (USA)); Lundblad, A. (University Hospital, Lund (Sweden). Dept. of Clinical Chemistry)

    1982-01-15

    A radioimmunoassay is described that allows rapid determination of a urinary oligosaccharide - Glc..cap alpha..1-6Glc..cap alpha..1-4Glc..cap alpha..1-4Glc ((Glc)/sub 4/) - at concentrations >2pmol/..mu..l. Antibodies produced in rabbits immunized with the phenethylamine derivative of (Glc)/sub 4/ coupled to keyhole limpet hemocyanin bind tritiated (Glc)/sub 4/-alditol. Studies comparing the activities of (Glc)/sub 4/ and several of its derivatives and analogues as inhibitors of binding of tritiated (Glc)/sub 4/-alditol show that (Glc)/sub 4/ is detected with maximum specificity and sensitivity only after reduction to (Glc)/sub 4/-alditol. Quantitation of (Glc)/sub 4/ in urine samples reduced with sodium borohydride gives excellent agreement with a previously used but more laborious method that employs gas-liquid chromatography-mass spectrometry (GLC/MS) (correlation coefficient = 0.98). Studies of the excretion rate of (Glc)/sub 4/ in urine of women during pregnancy using the radioimmunoassay method confirm and extend previous results using the GLC/MS method.

  5. Radioimmunoassay method for determination of 3, 3', 5'-triiodothyronine (reverse - T3)

    International Nuclear Information System (INIS)

    Kosowicz, J.

    1979-01-01

    To introduce radioimmunoassay, 3, 3', 5'-triiodothyronine (reverse-T 3 ) was coupled to bovine serum albumin by the carbodiimide technique and rabbits were immunized with the conjugates obtained. The immunizations were performed by multiple site intradermal injections at places in which cornynebacterium parvum was previously injected to enhance immunologic reaction. After 3 months the rabbits raised antisera to reverse-T 3 of a high titer and specificity. To obtain labelled 125 I-reverse T 3 , 3,3'-diiodothyronine was used. Iodination was performed by the chloramine T technique and the iodination mixture was subjected to gel filtration on Sephadex G-25 (fine) column. The purified monolabelled 125 I-reverse T 3 had a specific activity of 3,000 milli Curie/mg. The reverse T 3 radioimmunoassay of a high sensitivity (ca 2 pg/tube) was introduced in the clinical studies and facilitated direct determination of reverse T 3 in sera without the need of plasma extractions. The interference of serum proteins (TBG) was avoided by adding 8-anilino-1-naphtalene sulfonic acid to serum samples. Separation of free from antibody bound antigens was achieved by polyethylene glycol precipitation or immunoprecipitation. (author)

  6. Radioimmunoassay determination of urinary prostaglandins in patients with progressive systemic sclerosis

    International Nuclear Information System (INIS)

    Ramirez P, P.; Erbessd, M.L.; Mares, G.; Recinos, G.; Graef S, A.; Lavalle, C.

    1985-01-01

    The results of urinary determinations of E-2 prostaglandines by radioimmunoassay (RIA) in 24-hour urine are presented for three groups: progressive systemic sclerotic patients with normotension and with elevated or normal APR, progressive systemic sclerotic patients with hypertension and with normal or low APR, control group of normal subjects. In a recent report of progressive systemic sclerosis in patients we demonstrated changes in the urine concentratrion of APR levels, sodium excretion and in total blood volume. Based on these findings we felt the need to perform quantifications of E-2 prostaglandines (PGE-2) in 24-hour recently taken urine samples stored at 70 0 and measure the sodium amounts excreted in the urine. We concluded that urinary determination of E-2 prostaglandines was the most suitable for our study as it allowed the establishment of relationships between APR, aldosterone and metabolic sodium balance. (author)

  7. Average concentrations of FSH and LH in seminal plasma as determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Milbradt, R.; Linzbach, P.; Feller, H.

    1979-01-01

    In 322 males, 25 to 50 years of age, levels of LH and FSH respectively were determined in seminal plasma by radioimmunoassay. Average values of 0,78 ng/ml and 3,95 ng/ml were found as for FSH and LH respectively. Sperm count and motility were not related to FSH levels, but were to LH levels. A high count of spermatozoa corresponded to high concentration of LH, and normal motility was associated with higher levels of LH as compared to levels associated with asthenozoospermia. With respect to count of spermatozoa of a single or the average patient, it is suggested that the ratio of FSH/LH would be more meaningful than LH level alone. (orig.) [de

  8. Comparative determination of the rheumatic factor by means of agglutination, immunofluorescence and radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, L.; Storz, H.; Hein, G.; Schlenvoigt, G. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Bereich Medizin)

    1982-01-01

    The rheumatic factor (RF) was determined by means of agglutination, immunofluorescence (IF) test and radioimmunoassay (RIPEGA) in random groups of 56 patients with rheumatoid arthritis (RA), 13 patients with seronegative RA and 39 patients with psoriasis arthropathica. All three methods are of equal value with regard to the number of positive results. Further classification of seronegative patients, i.e. patients with a negative agglutination reaction and the clinical symptoms of RA is possible with the IF method and, above all, by means of RIPEGA. But because of the comprehensive test devices the two methods are only an alternative. Titer differences are attributed to the different indication principles and the immunological heterogeneity of RF. An improvement of the diagnosis of activity was not possible.

  9. Importance of radioimmunoassay for the determination of tumor markers in the diagnosis of malignant lymphomas

    International Nuclear Information System (INIS)

    Purizhanskij, I.I.; Pavlichuk, S.N.; Toritsina, L.K.

    1989-01-01

    The investigation was conducted to study the role of the determination of tumor markers (CEA, β 2 -microglobulin, IgE and ferritin) in patients with malignant lymphomas. Altogether 66 patients with Hodgkin's disease, 60 with non-Hodgkin's lymphomas and 15 with clinocohematological remission over one year were investigated, using radioimmunoassay with commercial kits of reagents. An increase in the level of β 2 -MG was shown to depend on the spreading of a lymphoproliferative process. An elevated level of IgE was noted in Hodgkin's disease whereas a significant rise was unnoticed in non-Hodgkin's lymphomas. An increase in the level of serum ferritin was noted in an advanced and aggressive lymphoproliferative process. The CEA test in malignant lymphomas is not informative

  10. Comparative determination of the rheumatic factor by means of agglutination, immunofluorescence and radioimmunoassay

    International Nuclear Information System (INIS)

    Jaeger, L.; Storz, H.; Hein, G.; Schlenvoigt, G.

    1982-01-01

    The rheumatic factor (RF) was determined by means of agglutination, immunofluorescence (IF) test and radioimmunoassay (RIPEGA) in random groups of 56 patients with rheumatoid arthritis (RA), 13 patients with seronegative RA and 39 patients with psoriasis arthropathica. All three methods are of equal value with regard to the number of positive results. Further classification of seronegative patients, i.e. patients with a negative agglutination reaction and the clinical symptoms of RA is possible with the IF method and, above all, by means of RIPEGA. But because of the comprehensive test devices the two methods are only an alternative. Titer differences are attributed to the different indication principles and the immunological heterogeneity of RF. An improvement of the diagnosis of activity was not possible. (author)

  11. Evaluation of extraction methods for progesterone determination in rabbit (Oryctolagus cuniculus) feces by radioimmunoassay

    International Nuclear Information System (INIS)

    Korndoerfer, Clotilde Maria; Meirelles, Cyro Ferreira; Bueno, Ives Claudio da Silva; Abdalla, Adibe Luiz

    1998-01-01

    The purpose of this study was to find a practical procedure for the extraction of progesterone (P 4 ) from feces and to determine if the P4 plasma profiles during pregnancy were reflected in total fecal P4 of pregnant rabbits. The rabbit was used as model for the techniques. Plasma and feces were collected from 11 rabbits during a period of 42 days. Three different methods of P4 extraction were used. The total P4 was measured by solid-phase radioimmunoassay (RIA) with 125 I-P4 as the tracer. Results suggested that it was possible to extract total P4 from rabbit feces with methanol and petroleum ether. Plasma and fecal P4 profiles were compared for both pregnant and ovariectomized rabbits. It was possible to differentiate total P4 extracted from day two through 28 after breeding (p<0.01). (author)

  12. Evaluation of extraction methods for progesterone determination in rabbit (Oryctolagus cuniculus) feces by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Korndoerfer, Clotilde Maria; Meirelles, Cyro Ferreira; Bueno, Ives Claudio da Silva; Abdalla, Adibe Luiz [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Secao de Ciencias Animais]. E-mail: cfmeirel@esalq.usp.br

    1998-07-01

    The purpose of this study was to find a practical procedure for the extraction of progesterone (P{sub 4}) from feces and to determine if the P4 plasma profiles during pregnancy were reflected in total fecal P4 of pregnant rabbits. The rabbit was used as model for the techniques. Plasma and feces were collected from 11 rabbits during a period of 42 days. Three different methods of P4 extraction were used. The total P4 was measured by solid-phase radioimmunoassay (RIA) with {sup 125} I-P4 as the tracer. Results suggested that it was possible to extract total P4 from rabbit feces with methanol and petroleum ether. Plasma and fecal P4 profiles were compared for both pregnant and ovariectomized rabbits. It was possible to differentiate total P4 extracted from day two through 28 after breeding (p<0.01). (author)

  13. Intracellular Signalling by C-Peptide

    Directory of Open Access Journals (Sweden)

    Claire E. Hills

    2008-01-01

    Full Text Available C-peptide, a cleavage product of the proinsulin molecule, has long been regarded as biologically inert, serving merely as a surrogate marker for insulin release. Recent findings demonstrate both a physiological and protective role of C-peptide when administered to individuals with type I diabetes. Data indicate that C-peptide appears to bind in nanomolar concentrations to a cell surface receptor which is most likely to be G-protein coupled. Binding of C-peptide initiates multiple cellular effects, evoking a rise in intracellular calcium, increased PI-3-kinase activity, stimulation of the Na+/K+ ATPase, increased eNOS transcription, and activation of the MAPK signalling pathway. These cell signalling effects have been studied in multiple cell types from multiple tissues. Overall these observations raise the possibility that C-peptide may serve as a potential therapeutic agent for the treatment or prevention of long-term complications associated with diabetes.

  14. Application of reaction type of C-peptide release test in diabetes mellitus

    International Nuclear Information System (INIS)

    Chen Dong; Duan Wenruo; He Juan; Lu Zhenfang

    2001-01-01

    The author is to confirm the effect of C-peptide release test and types of release reaction in appraisal of pancreas function of β-cell and selection of treatment for diabetes mellitus (DM) patients. The serum C-peptide release test of 67 normal controls and 217 DM patients were determined by RIA, and the results were analyzed and compared. C-peptide release test can reflect the pancreas function of β-cell better, the peak of C-peptide ≥ 0.6 nmol/L after lunch can be the limit of whether to reduce the level of blood glucose only by oral drug. The authors should adjust the treatment through analyzing the type of C-peptide release reaction. C-peptide release test is very important in evaluating the pancreas function of β-cell, classifying the type of DM and selecting the treatment

  15. Three-site sandwich radioimmunoassay with monoclonal antibodies for a sensitive determination of human alpha-fetoprotein

    International Nuclear Information System (INIS)

    Nomura, M.; Imai, M.; Takahashi, K.; Kumakura, T.; Tachibana, K.; Aoyagi, S.; Usuda, S.; Nakamura, T.; Miyakawa, Y.; Mayumi, M.

    1983-01-01

    Utilizing monoclonal antibodies against human alpha-fetoprotein, 3 distinct antigenic determinants were identified. These antigenic determinants, provisionally designated a, b and c, were arranged in such a manner that the binding of one determinant with the corresponding antibody did not inhibit, or only barely inhibited the binding of antibodies directed to the other 2 determinants. Monoclonal antibodies with 3 different specificities were, therefore, applied to develop a sandwich-type solid-phase radioimmunoassay of the antigen in which wells were coated with anti-a, and radiolabeled anti-b together with radiolabeled anti-c was employed to detect the bound antigen. The 3-site sandwich radioimmunoassay involving 3 different determinants gave a higher sensitivity than 2-site assays in which only anti-b or anti-c was employed as a radiolabeled reagent, because the radioactivity of the 2 labeled antibodies was added on the antigen bound to immobilized anti-a. (Auth.)

  16. Development of SI-traceable C-peptide certified reference material NMIJ CRM 6901-a using isotope-dilution mass spectrometry-based amino acid analyses.

    Science.gov (United States)

    Kinumi, Tomoya; Goto, Mari; Eyama, Sakae; Kato, Megumi; Kasama, Takeshi; Takatsu, Akiko

    2012-07-01

    A certified reference material (CRM) is a higher-order calibration material used to enable a traceable analysis. This paper describes the development of a C-peptide CRM (NMIJ CRM 6901-a) by the National Metrology Institute of Japan using two independent methods for amino acid analysis based on isotope-dilution mass spectrometry. C-peptide is a 31-mer peptide that is utilized for the evaluation of β-cell function in the pancreas in clinical testing. This CRM is a lyophilized synthetic peptide having the human C-peptide sequence, and contains deamidated and pyroglutamylated forms of C-peptide. By adding water (1.00 ± 0.01) g into the vial containing the CRM, the C-peptide solution in 10 mM phosphate buffer saline (pH 6.6) is reconstituted. We assigned two certified values that represent the concentrations of total C-peptide (mixture of C-peptide, deamidated C-peptide, and pyroglutamylated C-peptide) and C-peptide. The certified concentration of total C-peptide was determined by two amino acid analyses using pre-column derivatization liquid chromatography-mass spectrometry and hydrophilic chromatography-mass spectrometry following acid hydrolysis. The certified concentration of C-peptide was determined by multiplying the concentration of total C-peptide by the ratio of the relative area of C-peptide to that of the total C-peptide measured by liquid chromatography. The certified value of C-peptide (80.7 ± 5.0) mg/L represents the concentration of the specific entity of C-peptide; on the other hand, the certified value of total C-peptide, (81.7 ± 5.1) mg/L can be used for analyses that does not differentiate deamidated and pyroglutamylated C-peptide from C-peptide itself, such as amino acid analyses and immunochemical assays.

  17. Correlation of the sectetion of insulin and C-peptide in cancer patients

    International Nuclear Information System (INIS)

    Modnikov, O.P.; Lomtev, N.G.

    1983-01-01

    Insulin and C-peptide levels were studied with a radioimmunoassay in the peripheral blood serum of 44 patients with gastric and cervical cancer and 22 healthy persons. Hyperfunction of the pancreatic insular apparatus was shown in cancer patients which was expressed in a statistically significant increase in the C-peptide level. In gastric cancer patients hyperfunction of the insular apparatus was accompanied by hypoinsulinemia, and in cervical cancer patients by hormoinsulinemia. An analysis has shown that the ratio insulin/C-peptide in gastric and cervical cancer patients was about the same and significantly lower than the control. A conclusion has been made that in spite of difference in the initial insulin concentration, the same phenomenon - acceleration of the metabolic clearance of insulin - occurs in patients with cancer of the above sites. The C-peptide level decreased, the ratio insulin/C-peptide increased, i.e. hyperfunction of the insular apparatus disappeared and the metabolic clearance of insulin slowed down

  18. Correlation of the secretion of insulin and C-peptide in cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Modnikov, O P; Lomtev, N G [Kirgizskij Nauchno-Issledovatel' skij Inst. Onkologii i Radiologii, Frunze (USSR)

    1983-08-01

    Insulin and C-peptide levels were studied with a radioimmunoassay in the peripheral blood serum of 44 patients with gastric and cervical cancer and 22 healthy persons. Hyperfunction of the pancreatic insular apparatus was shown in cancer patients which was expressed in a statistically significant increase in the C-peptide level. In gastric cancer patients hyperfunction of the insular apparatus was accompanied by hypoinsulinemia, and in cervical cancer patients by hormoinsulinemia. An analysis has shown that the ratio insulin/C-peptide in gastric and cervical cancer patients was about the same and significantly lower than the control. A conclusion has been made that in spite of difference in the initial insulin concentration, the same phenomenon - acceleration of the metabolic clearance of insulin - occurs in patients with cancer of the above sites. The C-peptide level decreased, the ratio insulin/C-peptide increased, i.e. hyperfunction of the insular apparatus disappeared and the metabolic clearance of insulin slowed down.

  19. Somatomedin A in human serum: determined by radioimmunoassay and radioreceptorassay; results and implications

    International Nuclear Information System (INIS)

    Hall, K.; Sara, V.

    1981-01-01

    The polypeptide hormones in the somatomedin family were discovered as three different biological activities of serum: insulin-like activity (ILA), sulphation factor activity (SFA) and multiplication stimulatory activity (MSA). Three different biological actions on three different target tissues have been used to identify the somatomedins during their purification. All the somatomedins contain ILA, SFA and MSA but their order of potency of biological action varies from tissue to tissue. It is apparent that the pattern of somatomedin levels determined throughout human life varies according to the technique used for their determination. Each assay has a unqiue order of crossreaction for the various somatomedins, and is sensitive to different forms present in blood. Thus the different patterns must reflect the predominance of specific somatomedins at certain stages of life. The heterogeneity of polypeptide hormones in the circulating blood is well recognized but its relation to age and development has yet to be fully explored. Methods for the estimation of the somatomedins must take account of such differences. In the radioimmunoassay field it is generally recognized that each type of antibody has a unique recognition pattern. This applies equally to the radioreceptorassay where the specificity of the receptor varies according to species, organ and age. Consequently, it is essential that age-related standards are established for each technique for the determination of somatomedins. (Auth.)

  20. Applications of a solid phase radioimmunoassay (SPRIA) to the micro-determination of ABO blood group

    International Nuclear Information System (INIS)

    Wu Fenqiang; Guo Jingyuan

    1995-01-01

    The authors report a simple, rapid, sensitive and accurate solid phase radioimmunoassay (SPRIA) method which has been improved. The research included the tests of its methodological parameters, sensitivity, accuracy, and the studies on its applications to the detection of blood group substances in varied forensic biological materials. The coefficient variation of intra-assay was 5.6%, and that of inter-assay was 10.15%. As to its applications to the forensic serology, the ABO blood groups of human bloodstain, hair follicular tissues and salivary stains had been tested and the results were satisfying. Later, 50 unknown type bloodly samples had been blind tested. The judging level used to identify the positive and negative wells was 800 cpm, that meant, if the radioactive count of a well were over 800 cpm, it was determined as a positive well, if that of a well were below 800 cpm, it was negative well. As SPRIA is a method of micro-determination which can micro-test the blood group antigens contained in varied forensic biological materials, it should has a good future of its applications to the forensic medicine fields

  1. Determination of plasma aldosterone in children by thin layer chromatography and radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Parth, K; Zimprich, H; Brunel, R [The Ludwig Boltzmann Institute of Paediatric Endocrinology; The Karolinen Kinderspital, Vienna)

    1976-01-01

    An accurate and relatively simple radioimmunoassay for the determination of aldosterone concentration in peripheral plasma has been developed. 0.5-2.0 ml plasma with added ..cap alpha..1.2-/sup 3/H..omega..aldosterone is extracted with dichloromethane. Purification of the extract is achieved by thin layer chromatography in the system benzene-acetone 1:1. Recovery of ..cap alpha..1,2-/sup 3/H..omega..aldosterone is 58+-6 (sd) %. Bound and free fractions are separated by dextran-coated charcol. The intra-assay reproducibility is 8.8 % and the inter-assay reproducibility varies from 11.4-16.1%. The sensitivity of the assay for a 5 ml plasma sample can be put at 0.2 ng/100 ml. Normal values determined in 52 healthy children of different age groups are presented. Furthermore the aldosterone stimulating effect of low sodium diet (17 children), severe and prolonged vomiting (19 children) and synthetic ACTH (10 children) has been studied by our modified method.

  2. A method for tissue extraction and determination of prostate concentrations of endogenous androgens by radioimmunoassay

    International Nuclear Information System (INIS)

    Albert, J.; Geller, J.; Geller, S.; Lopez, D.

    1976-01-01

    A method for simultaneously determining concentrations of major androgens in prostate has been developed. Extraction techniques used to isolate the androgens from minced tissue include homogenization with high-speed blades in Delsal's solvent mixture, adsorption to silica gel, followed by column and one thin-layer chromatography (TLC). Radioimmunoassays (RIA) of small aliquots of TLC eluates are used to quantitate picogram amounts of 5α-dihydrotestosterone (DHT) and 5α-androstanediols (Diol) and to estimate testosterone (T) and androstenedione (Ad). Contamination of blanks was reduced to RIA sensitivity limits primarily by treatment of glassware in a self-cleaning oven. The specificity of the method for each androgen was established by TLC separations of known prostate metabolites, antisera specificities, and parallelism of sample aliquots to androgen RIA standards. The overall precision, in terms of coefficients of variation, was 21% for DHT and 24% for Diol. T and Ad could not be measured with acceptable precision because their very low concentrations in prostate (<=0.5 ng/g tissue) were less than RIA sensitivity limits. Accuracy studies indicated recoveries ranging from 96% for Diol to 121% for DHT. In human benign hypertrophic prostate tissue, DHT averaged 153 ng/g soluble protein (5.8 ng/g tissue) which was 17 times higher than values obtained in human spleen and kidney; Diol in prostate showed no consistent differences from values noted in kidney or spleen

  3. Basic and clinical study on determination of gastrin in the blood by radioimmunoassay

    International Nuclear Information System (INIS)

    Yonahara, Yoshio; Kato, Masayuki; Kashima, Hiroshi; Ito, Yasushi; Takahara, Yoshiko

    1975-01-01

    The usefulness of a radioimmunoassay kit in the determination of gastrin in the blood was examined with the following results. (1) The kit is best used within two weeks during which time its specific radioactivity remains high. Correction of the pH of the buffer solution must be conducted without fail. (2) If the temperature and time of the incubation are strictly controlled, it is possible to obtain almost the same results for each condition of time and temperature. (3) As for reproducibility, scattering was observed to some extent at high concentrations, but little at low concentrations. The recovery rate was as good as 100.6% on the average, indicating the usefulness of this method in clinical tests. (4) In 30 normal subjects, the blood levels of gastrin ranged from 52 to 123 (average 86.8 23.3) pg/ml. In gastric ulcers and duodenal ulcers, it was normal or slightly higher. Further, duodenal ulcers showed higher blood levels than did gastric ulcers, and chronic gastritis showed values slightly higher than normal. It was also interesting that blood levels of gastrin were unusually high in megaloblastic anemias. (author)

  4. The determination of antithrombin III by radioimmunoassay and its clinical application

    International Nuclear Information System (INIS)

    Chan, V.; Chan, T.K.; Wong, V.; Tso, S.G.; Todd, D.

    1979-01-01

    A radioimmunoassay (RIA) has been developed for the determination of antithrombin III (AT III) in man. The detection limit was 25 μg/dl. At III-RIA level and biological activity (anti-Xa) was significantly correlated (r = 0.737, P < 0.0001). Plasma levels in 36 healthy males (mean +- SD, 19.9 +- 2.5 mg/dl) and 21 healthy females (19.1 +- 2.4 mg/dl) were similiar. Serial AT III measurements in normal menstruating females showed lower levels during midcycle and higher concentrations during menstruation. In carcinomas, the AT III levels were lower than normal, particularly in hepatocellular carcinoma. In cirrhosis of liver, the levels were markedly decreased and in some patients were below that found in congenital AT III deficiency. Patients with deep vein thrombosis and patients with heart valve replacement had lower levels than normal, while patients with cerebral vascular occlusion had normal levels. The possible use of AT III as a diagnostic tool of post-operative deep vein thrombosis was demonstrated in one patient after hysterectomy. The increased sensitivity, specificity and precision of this type of assay offer distinct advantages over existing methods of AT III estimation. (author)

  5. Radioimmunoassay determination of the effect on animal reproduction of alternative of feeding suplementation in dairy cows

    International Nuclear Information System (INIS)

    Villalba, Patricio; Ambuludi, Eduardo

    1993-01-01

    The principal object of this trial was to evaluate the influence of three alternatives of feeding suplementation in dairy cows in the post-partum period in ecuadorian highlands. Thirty sic animals in fist lactation were used in this experiment and were divided in three groups according to the feed intake: Group A diet was 5 Kg. of a commercial concentrate mixture with 12 per cent of crude protein plus pasture ad libitum; Group B diet was green banans (Musa paradisiaca) and pasture and Group C diet was the control only pasture. Using Radioimmunoassay technique (RIA), progesterone values were determinated in milk from each cow. the sampling was sequential, two samples a week, starting 6 days after parturition, until the animal was pregnant or until the study was finished, 150 days after post-partum for each cow. This research allowed us to evaluate the ovaric post-partum activity of each group: Frequency and length of the oestrus cycles; efficiency of oestrus detection, calving-first, oestrus period, calving-conception length, conception rate, and services per conception. Additional datas were used in this study such as: milk production, palpations and treatments

  6. Development of a radioimmunoassay for the determination of buprenorphine in biological samples

    International Nuclear Information System (INIS)

    Debrabandere, L.; Boven, M. Van; Daenens, P.

    1993-01-01

    The development of a specific and sensitive radioimmunoassay for the detection of buprenorphine in urine samples is described. With minor adjustments, the assay was also applied to the analysis for buprenorphine in plasma samples. The 2-diazobenzoic acid derivative of buprenorphine has been prepared as a hapten. The immunization of rabbits with the hapten-bovine serum albumin conjugate resulted in the production of antibodies, which cross-reacted with N-dealkylbuprenophine up to about the 90% level. The antibodies showed very low cross-reactivities with the 3-O-glucuronides and with the structural analogue etorphine. The assay was mainly used to prescreen for buprenorphine in urine samples of persons suspected of Temgesic misuse and to determine buprenorphine in plasma samples. A linear calibration graph for buprenorphine was obtained after logit-log regression. The spiking recovery study showed a linear regression. Intra-and inter-assay relative standard deviations were -1 (Student's t-distribution, p 0.01, degrees of freedom = 8). (Author)

  7. A high-throughput mass spectrometry assay to simultaneously measure intact insulin and C-peptide.

    Science.gov (United States)

    Taylor, Steven W; Clarke, Nigel J; Chen, Zhaohui; McPhaul, Michael J

    2016-04-01

    Measurements of fasting levels of insulin and C-peptide are useful in documenting insulin resistance and may help predict development of diabetes mellitus. However, the specific insulin and C-peptide levels associated with specific degrees of insulin resistance have not been defined, owing to marked variability among immunoassays and lack of standardization. Herein, we describe a multiplexed liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for intact insulin and C-peptide. Insulin and C-peptide were enriched from patient sera using monoclonal antibodies immobilized on magnetic beads and processed on a robotic liquid handler. Eluted peptides were analyzed by LC-MS/MS. Bovine insulin and a stable isotopically-labeled (13C/15N) C-peptide were utilized as internal standards. The assay had an analytical measurement range of 3 to 320 μIU/ml (18 to 1920 pmol/l) for insulin and 0.11 to 27.2 ng/ml (36 to 9006 pmol/l) for C-peptide. Intra- and inter-day assay variation was less than 11% for both peptides. Of the 5 insulin analogs commonly prescribed to treat diabetes, only the recombinant drug insulin lispro caused significant interference for the determination of endogenous insulin. There were no observed interferences for C-peptide. We developed and validated a high-throughput, quantitative, multiplexed LC-MS/MS assay for intact insulin and C-peptide. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Comparative determination of phenytoin by spectrophotometry, gas chromatography, liquid chromatography, enzyme immunoassay, and radioimmunoassay

    International Nuclear Information System (INIS)

    Castro, A.; Ibanez, J.; DiCesare, J.L.; Adams, R.F.; Malkus, H.

    1978-01-01

    Sera from patients being treated with phenytoin were analyzed for the drug by spectrophotometry, gas chromatography, radioimmunoasay, enzyme immunoassay, and liquid chromatography. The assay values obtained were intercompared statistically. Enzyme immunoassay and liquid chromatography appear to be attractive alternatives to the more traditional methods of spectrophotometry and gas chromatography. Our radioimmunoassay data correlated poorly with results by the four other methods

  9. Determination of progesterone for reproduction control in cows using a 3H radioimmunoassay. 1

    International Nuclear Information System (INIS)

    Taubert, H.; Barth, T.; Hempel, G.; Graeser, K.

    1984-01-01

    For verification of cow fertility a 3 H radioimmunoassay of progesterone in milk and blood plasma was developed. It is of high specificity and accuracy as well. Extraction of progesterone from milk was facilitated by application of alcohol. Suggested differences in milk and plasma progesterone levels between pregnant and nonpregnant cows could be revealed

  10. Therapeutic drug monitoring by radioimmunoassay: Determination of aminoglycoside antibiotics and vancomycin in plasma

    International Nuclear Information System (INIS)

    Glaubitt, D.; Drechsler, H.J.; Knoch, K.; Siafarikas, K.

    1984-01-01

    Radioimmunoassay of aminoglycoside antibiotics (gentamicin, tobramycin, netilmicin) or vancomycin in plasma may considerably aid to assess their appropriate dosage and, if necessary, to rapidly adjust it to the assumed requirement. Thus the dosage of the antibiotic is kept large enough as to lead to the desired therapeutic result but not as high as to cause side effects. (orig.)

  11. Application of radioimmunoassays to determine steroids at the time of parturition in the cow

    International Nuclear Information System (INIS)

    Agthe, O.; Kolm, H.P.

    1976-01-01

    The influence of single or repeated intramuscular injections of 100 or 200 IU ACTH on peripheral plasma levels of oestrogens, progesterone and corticosteroids was studied in cows during late pregnancy. Radioimmunoassays were applied for measuring unconjugated oestrogens (oestrone and oestradiol-17β) and progesterone. For determining corticoids competitive protein binding was used. Five German black pied cows pregnant for 260-67 days were injected with ACTH either once (two cows with one single injection) or repeatedly (one cow with five and two cows with 12 injections) at 4-h intervals. Blood samples were drawn at 4- to 12-h intervals from one day before to four days after the beginning of ACTH application. Four cows served as control animals. Corticosteroid levels increased drastically from about 3 up to 30 ng/ml after ACTH injection. This effect lasted for 4-6h after a single injection and for 4-6h after the last of the repeated applications. Oestrogen and progesterone levels were not affected by single ACTH applications. If repeated injections were given, oestrogen levels increased from about 0.6 to levels above 1.2 ng/ml. In contrast to oestrogen, progesterone levels fell from 7 ng/ml to about 2 ng/ml during the first 24 h but returned to initial values within the following 24 h. In one cow, however, progesterone concentration remained below 2 ng/ml. In this animal premature parturition occurred on day 270, i.e. 2 days after the last injection. (author)

  12. Use of radioimmunoassay for quantitative determination of progesterone in milk samples from dairy cows in Zimbabwe

    International Nuclear Information System (INIS)

    Freymark, P.J.; McCabe, C.T.

    1986-01-01

    A maximum 90-day service interval is an important economic factor in dairying. The determination of pregnancy at 21 to 26 days post-insemination can ensure that particular attention is paid to non-pregnant cows at subsequent heats, and thus help reduce this interval. In Zimbabwe a radioimmunoassay for milk progesterone using an iodinated tracer was developed in 1982 from a previously established assay for plasma progesterone. Progesterone antiserum is produced locally and the assay is used as an early pregnancy diagnosis test in dairy cattle. During 1983 two pilot schemes were instituted to investigate breed differences, logistics, and feasibility under the local conditions, and to identify constraints. Milk samples taken 24 days post-insemination were found to differentiate best between pregnant and non-pregnant cows for both major breeds in the country (Friesian/Holstein and Jersey). Pregnant cows had an average of 13.76 ng/mL (+-1.06) progesterone on day 24 while non-pregnant cows averaged 0.34 ng/mL (+-0.13) of progesterone. Apparently 12.2% of cows subsequently lost their embryos after day 24, and these cows averaged 9.98 ng/mL (+-1.52). Milk samples were also taken on the day of insemination; the results showed that 11% of cows were incorrectly inseminated when progesterone concentrations were high (2.59 ng/mL+-0.80). A National Early Pregnancy Diagnosis Scheme using milk progesterone was implemented in December 1984 and results to date are discussed in the paper. (author)

  13. Development and standardization of radioimmunoassay technique for human proinsulin determining and its use in the study of type II diabetes mellitus associated to obesity

    International Nuclear Information System (INIS)

    Nascimento, Martha do

    1996-01-01

    The availability of immunoassay methodology for proinsulin is important to define its physiological and pathophysiological significance in humans. Serum concentration of proinsulin are elevated in patients with type II Diabetes Mellitus (NIDDM) and recently diagnosed Type I, so a raised circulating concentration of proinsulin may serve as an early indicator of β cells dysfunction. recently, in NIDDM the serum concentrations of proinsulin and its B-chain-C-peptide junctional split form, des (31-32), were found to correlate with diastolic blood pressure, a risk factor for cardiovascular disease. The development of a sensitive and specific radioimmunoassay (RIA) methodology for proinsulin has been difficult due to its low concentration in serum and the presence of proinsulin conversion intermediates in fluids and tissues. Also other potentially cross-reactive peptides, including insulin and C-peptide, can interfere in the assay. This work describe a highly specific human proinsulin RIA developed by using biosynthetic human proinsulin (hPI) as immunogen, standard and tracer. (author)

  14. Changes of serum leptin and c-peptide level in children with type 1 diabetic mellitus

    International Nuclear Information System (INIS)

    Du Tongxin; Wang Zizheng; Sun Junjiang; Wang Shukui; Qi Shaokang

    2001-01-01

    To deplore the relationship between leptin and c-peptide in children with type 1 diabetic mellitus (DM). The levels of serum leptin and c-peptide (C-P) in 65 type 1 DM children (including 31 before and after insulin treatment) and 30 normal controls were measured by radioimmunoassay (RIA). The results found that there was significant differences (P < 0.01) in leptin and C-P between DM children and normal controls, also in 31 DM children before and after treatment. It showed a positive correlation between leptin and C-P. The changes of the leptin/C-P ratio in DM children compared with normal controls and that before and after treatment were also significantly different. It suggested that leptin may have close relationship in the development, progress and the occurrence of complications in children with DM and also provide a new clue for their diagnosis treatment and complication occurrence

  15. Sensitivity and reproducibility of urinary C-peptide as estimate of islet B-cell function in insulin-treated diabetes

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Faber, O K

    1989-01-01

    The aims of the present study were to evaluate the ability of urinary C-peptide determination to demonstrate presence of residual insulin secretion, and to evaluate the reproducibility of urinary C-peptide excretion in 125 insulin-treated diabetic patients. C-peptide was determined in two...

  16. Ultrasensitive radioimmunoassay for direct determination of free triiodothyronine concentration in serum

    International Nuclear Information System (INIS)

    Weeke, J.; Oerskov, H.

    1975-01-01

    Free triiodothyronine (T 3 ) in serum has been measured directly in dialysates of serum, using a wick chromatographic radioimmunoassay. Adequate sensitivity was attained by the use of [ 125 I]T 3 with a very high specific activity (2,000 to 3,000μCi/μg). Sera were dialysed against a Krebs-Ringer bicarbonate buffer modified so as to be similar to plasma water. Dialysis took place under carefully controlled circumstances. The influence on the equilibrium of total to free T 3 of temperature, serum dilution and dialysis time was studied. By the present method, free T 3 in serum from groups of subjects including 20 men, 10 women taking oral contraceptives and 20 women with normal menstrual cycles were identical, averaging 5.2 pg/ml. A chromatographic radioimmunoassay of total T 3 using high specific activity [ 125 I]T 3 and a very small test sample is also described. (auth.)

  17. Release of leukotriene C4 from human polymorphonuclear leucocytes as determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Aehringhaus, U.; Woelbling, R.H.; Peskar, B.M.; Peskar, B.A.; Koenig, W.; Patrono, C.

    1982-01-01

    Rabbits were immunized with a conjugate of leukotriene (LT)C 4 and bovine serum albumin prepared by coupling the single free amino group of the hapten to the protein using gluteraldehyde. Binding of [ 3 H]LTC 4 to the antibodies obtained is inhibited by 50% with 1.5 ng LTC 4 . The relative cross-section of LTD 4 is 16% and of LTC 4 -methyl ester 3.6%. The validity of the radioimmunoassay was demonstrated by comparison with bioassay using the isolated guinea pig ileum. Using the radioimmunoassay it could be shown that endogenous LTC 4 is released in a dose-dependent manner by human polymorphonuclear leucocytes stimulated with the divalent cation ionophore A23187. (Auth.)

  18. A simplified radioimmunoassay for digoxin determination using a 125-I-labelled solid-phase kit

    International Nuclear Information System (INIS)

    Doering, W.; Bluemel, E.

    1978-01-01

    Our experience with a commercially available kit (Radioimmunoassay DIGOXIN, Boehringer, Mannheim) using ( 125 J)-labelled digoxin and antibody-coated tubes is reported. This simplified method requires only two pipetting steps per sample and results can be obtained in 70 min. The intra- and interassay coefficient of variation ranged between 7% and 8%. The specific digoxin antibody antibody gave no clinical relevant cross-reactions with spironolactone or prednisone ( [de

  19. Measurement of serum free thyroxine using fT4(fraction) determined by solidphase radioimmunoassay: First clinical results

    International Nuclear Information System (INIS)

    Reiners, C.; Walter, H.; Moll, E.; Boerner, W.

    1983-01-01

    The novel solidphase RIA SPAC ET permits the simultaneous determination of TF 4 , TT 4 and fT 4 -fraction. The duration until the complete results of this assay can be obtained is a little bit less than for parallel radioimmunologic FT 4 - and TT 4 -determinations. The results of our quality control survey indicate that the precision of the precommercial kits tested should be improved. In addition, the normal range of FT 4 from 5.5 pg/ml to 12.5 pg/ml should be adapted in the final assay version of the approximately 30% higher normal ranges which are common with alternative FT 4 -radioimunoassays. In comparison to FT 4 -I, TT 4 /TBG-ratio and other FT 4 -radioimmunoassays, the diagnostic accuracy of FT 4 determined by SPAC ET is equally good. Estrogen-mediated TBG elevations on oral contraceptives are well compensated. In pregnancy, the known tendency towards lower FT 4 levels can be seen with the beginning of the second trimester. While there are no changes of FT 4 levels on medication with acetylosalicyclic acid, a slight tendency towards lower FT 4 determined by SPAC ET can be seen on therapy with phenytoin. Under treatment with heparin, FT 4 by SPAC ET is elevated. This is more reasonable than the decreases of FT 4 concentrations observed with radioimmunoassays using FT 4 analogues as tracers. RIA SPAC ET is an interesting alternative to routinely used direct and indirect methods for determination of free thyroxine. (orig.) [de

  20. A new procedure for coupling antibody to paper discs for radioimmunoassay: application to the determination of alpha-fetoprotein

    International Nuclear Information System (INIS)

    Sasaki, T.; Tsukada, Y.; Hirai, H.

    1983-01-01

    Horse anti-alpha-fetoprotein was coupled to CM-cellulose discs by a modified carbodiimide reaction. The resulting coupled CM-discs were used in solid-phase radioimmunoassay of human alpha-fetoprotein. The sensitivity of these discs and conventional BrCN activated filter paper discs coupled anti-alpha-fetoprotein was approximately the same. A fair correlation between the alpha-fetoprotein levels determined by both methods was observed. The coupling procedure with carbodiimide is simple and the use of hazardous BrCN is eliminated. (Auth.)

  1. A simple method for the determination of the specific activity of 125I-tracer used in radioimmunoassay

    International Nuclear Information System (INIS)

    Bhupal, V.; Mani, R.S.

    1986-01-01

    The specific activity of the 125 I-thyroxin used in thyroxin radioimmunoassay (RIA) was determined by a simple method involving combination of RIA and displacement analysis. It was compared with the value obtained by the conventional method based on radioiodination data. It is indicated that even for a non-protein hormone like thyroxin the specific activity of 125 I-thyroxin derived from iodination data is not reliable. The specific activites obtained by displacement analysis were consistent with the experimental findings. (author)

  2. Comparative study of radioimmunoassay dates

    International Nuclear Information System (INIS)

    Venegas Sanchez, Ruth.

    1986-01-01

    The radioimmunoassay is frequently used in clinical chemistry for the concentration determination of several substances like hormones as thyrotropine and thyroxine. In this experiment the dates of tyroxine radioimmunoassay are processed by three methods: a) like the recommendation of the IAEA, b) Dr. G. Chase method, c) according to the provider. The best method was Dr. Chase's. (author)

  3. Thyroxine determination in serum by radioimmunoassay and competitive protein-binding analysis (simultaneous study using four test kits)

    International Nuclear Information System (INIS)

    Wagner, K.

    1978-01-01

    Three commercial test kits for radioimmunological T 4 -determination have been tested (T 4 -RIA Abbott, RIA-mat T 4 , T 4 -RIA Henning). The RIA method has also been compared with a CPBA test (Tetralute) for routine application. 1) The results show that CPBA (Tetralute) is superior over the three radioimmuno-assays with regard to intra-assay variance. The T 4 -RIA Abbott has been inferior to the two other RIA under test and to the Tetralute with regard to inter-assay variance. 2) The four test kits show significant differences and considerable deviations from the given nominal values in comparison with the mean values of two control sera. A control for correctness does not seem to be appropriate as it cannot be decided which of the test kits yields the true value of T 4 content. No systematic difference has been observed between RIA and CPBA in the determination of T 4 in control sera. 3) No detectable difference has been found among the RIA-T 4 test kits and comparing them with the CBPA test regarding their diagnostic precision. A good correlation of T 4 values of euthyroid patients comparing the Tetralute and the three radioimmunological test kits. The mean values of euthyroid sera obtained by the three radioimmuno-assays and the Tetralute are not in agreement with each other. (orig.) [de

  4. Trypsin radioimmunoassay

    International Nuclear Information System (INIS)

    Scheithauer, R.; Wolf, F.; Tympner, F.

    1981-01-01

    In 29 patients with suspicion of pancreatic disease standard secretin-pancreozymin-test was performed parallel to trypsin determination by radioimmunoassay before and after stimulation with secretin. Mean serum trypsin in normal subjects was 175 ng BIT/ml (range 90-250), the maximum after stimulation being 20 minutes after secreting injection (range 110-550). Preliminary normal values are 270 ng BIT/ml for basal concentration and 650 ng BIT/ml for 20 min after secretin stimulation. In the group of normals there was no case of misinterpretation. In patients with several pathological parameters (n = 10) basal trypsin concentration was increased in 7 cases, the stimulated value was concordant with the definite diagnosis in every case. Significant advantage for diagnostics was derived in patients having had pancreatic diseases before, however being actually normal with respect to standard diagnostic parameters. All these patients revealed increased trypsin concentrations after stimulation and 50% of them showed increased basal values. Equivocal results were seen in patients with endstage pancreatitis as well as in case of obstruction during reduced secretion. (orig.) [de

  5. Evaluation of a radioimmunoassay for the determination of anti-native DNA antibodies

    International Nuclear Information System (INIS)

    Johanet, C.; Soulie, E.; Absalon, Y.B.; Ocwieja, T.; Abuaf, N.

    1991-01-01

    The anti-native DNA antibodies were measured by a radioimmunoassay (RIA) type Farr assay in the sera from 648 patients: 108 with active or inactive systemic lupus erythematosus (SLE), 181 with clinical symptoms of another connective tissue disease, 171 with liver diseases, 29 with different pathology and 159 normal sera were obtained from a blood bank. The anti-DNA kit has been calibrated against the first international units/ml. This assay has proved to be sensitive and specific, and appears to be reliable for the diagnosis and follow-up of SLE patients. The authors propose a new reference cut-off level higher than producer's one [fr

  6. Presence of melatonin in various cat brainstem nuclei determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Sallanon, M.; Touret, M.; Claustrat, B.

    1982-01-01

    Microdissected samples of juvenile cat brain tissue were assayed for melatonin content using a double antibody radioimmunoassay. Immunoreactive melatonin was consistently detected, albeit in variable amounts, in pineal, habenula, the region of the nucleus gracilis, gigantocellular reticular formation of the pons and medulla oblongata. Among the negative areas were raphe nuclei, substantia nigra dn locus caeruleus. These findings suggest that melatonin may play a role in some structures of the central nervous system outside the pineal-hypothalamo-pituitary axis. This immunoreactive melatonin could reflect a local synthesis, or a tissular uptake of melatonin from blood or cerebrospinal fluid. (author)

  7. HBsAg d and y subtypes determined by inhibition radio-immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, R [Border Blood Transfusion Service, East London (South Africa)

    1981-12-01

    An inhibition radioimmunoassay for the detection of HBsAg/d and HBsAg/y antigens is described. A survey of 211 asymptomatic HBsAg positive blood donors showed 190 to be of type HBsAg/d and 3 to be of type HBsAg/y, while the remaining 18 could not be typed. Of 43 patients with acute hepatitis 39 were type HBsAg/d and 4 were type HBsAg/y. The statistically significant (p smaller than 0,01) increase in type HBsAg/y may reflect a changing pattern in offending viral strain with the passage of time.

  8. Local preparation and evaluation of liquid phase radioimmunoassay for determination of human serum cortisol

    International Nuclear Information System (INIS)

    Sallam, Kh.M.; El-Bayoumy, A.S.A.; Ebeid, N.H.; Michael, E.; Zein, N.; Elfarargy, Ah.F.

    2017-01-01

    The main objective of the present study was the preparation of the primary reagents of cortisol radioimmunoassay (RIA) using liquid phase double antibody technique. Three basic components were prepared and characterized to obtain valid and accurate system. These components were polyclonal anti-cortisol antibody, "1"2"5I-cortisol RIA tracer and cortisol standards. Cortisol requires conjugation step to be real antigen. Therefore, in this study this mandatory conjugation step was performed & characterized. Then formulation, optimization and validation of this liquid phase RIA technique were carried out. This assay is precise, specific and sensitive enough for using as a diagnostic tool for the adrenal cortex status. (author)

  9. Circulating Dopamine and C-Peptide Levels in Fasting Nondiabetic Hypertensive Patients

    OpenAIRE

    Tomaschitz, Andreas; Ritz, Eberhard; Kienreich, Katharina; Pieske, Burkert; M?rz, Winfried; Boehm, Bernhard O.; Drechsler, Christiane; Meinitzer, Andreas; Pilz, Stefan

    2012-01-01

    OBJECTIVE Accumulating evidence supports a potential role for dopamine in the regulation of insulin secretion. We examined the association between circulating dopamine and C-peptide concentrations using data from the Graz Endocrine Causes of Hypertension (GECOH) study. RESEARCH DESIGN AND METHODS After 12 h of fasting, we measured plasma dopamine and serum C-peptide levels and established determining factors of insulin secretion in 201 nondiabetic hypertensive patients (mean age 48.1 ? 16.0 y...

  10. C-Peptide Is a Sensitive Indicator for the Diagnosis of Metabolic Syndrome in Subjects from Central Mexico.

    Science.gov (United States)

    Gonzalez-Mejia, M Elba; Porchia, Leonardo M; Torres-Rasgado, Enrique; Ruiz-Vivanco, Guadalupe; Pulido-Pérez, Patricia; Báez-Duarte, Blanca G; Pérez-Fuentes, Ricardo

    2016-05-01

    Metabolic Syndrome (MetS) is associated with elevated risk for developing diabetes and cardiovascular disease. A key component of MetS is the development of insulin resistance (IR). The homeostatic model assessment (HOMA) model can determine IR by using insulin or C-peptide concentrations; however, the efficiency of insulin and C-peptide to determine MetS has not been compared. The aim of the study was to compare the efficiency of C-peptide and insulin to determine MetS in Mexicans. Anthropometrics, glucose, insulin, C-peptide, triglycerides, and high-density lipoproteins were determined in 156 nonpregnant females and 114 males. Subjects were separated into normal or positive for MetS. IR was determined by the HOMA2 calculator using insulin or C-peptide. Correlations were calculated using the Spearman correlation coefficient (ρ). Differences between correlations were determined by calculating Steiger's Z. The sensitivity was determined by the area under receiver operating characteristics curve (AUC) analysis. Independent of the MetS definition [Adult Treatment Panel III (ATP III), International Diabetes Federation (IDF), or World Health Organization (WHO)], C-peptide and insulin were significantly higher in MetS subjects (P indicator of MetS. Since C-peptide has recently emerged as a biomolecule with significant importance for inflammatory diseases, monitoring C-peptide levels will aid clinicians in preventing MetS.

  11. Gonadotropin determination in 24-h-urine by sensitive LH and FSH radioimmunoassays

    International Nuclear Information System (INIS)

    Raid, A.; Fenske, M.; Koenig, A.

    1979-01-01

    Urinary lutropin (LH) and follitropin (FSH) were precipitated with acetone and measured by specific radioimmunoassays. Recovery experiments with special regard to urinary pH values were done by adding 125 I-labelled LH and FSH to unprocessed urine. At pH 4.5 68.6% of LH and 66.1% of FSH were recovered. Increasing pH values up to 6.0 resulted in a significant recovery loss of 125 I-LH, but not of 125 I-FSH. Immunoreactive FSH concentrations decreased significantly 6 and 48 hours after starting storage at room temperature. In healthy males and females there were found mean LH and FSH concentrations in 24-h-urine which were similar to those reported by others: LH: males: 22.6 IU; cycling females: 17.8 IU; postmenopausal females: 49.1 IU; FSH: males 6.0 IU; cycling females: 15.0 IU; postmenopausal females: 48.5 IU. Because of their high sensitivity and practicability. These radioimmunoassays could be clinically useful approaches in assessment of pituitary and gonadal disorders in human subjects. (author)

  12. Determination of polycyclic aromatic hydrocarbons in urine from coke-oven workers with a radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Herikstad, B.V.; Ovrebo, S.; Haugen, A.; Hagen, I. (Center for Industrial Research, Oslo (Norway))

    1993-02-01

    Considerable amounts of polycyclic aromatic hydrocarbons (PAH) are present in the workplace. In order to obtain a better understanding of the occupational hazards connected with PAH exposure various biomonitoring methods need to be applied. The level of PAH in urine collected from coke-oven workers has been measured by a recently developed radioimmunoassay. A significant correlation between estimated exposure levels for PAH and urinary levels of PAH was observed. During the winter period the control group was found to have an average concentration of 0.44 ng PAH/mmol creatinine, whereas the low, medium and high exposure groups contained 0.44, 0.71 and 0.85 ng PAH/mmol creatinine respectively. The urinary PAH level in the samples collected during the summer period was higher, i.e. 0.81, 0.94 and 1.10 ng PAH/mmol creatinine, for the low, medium and high exposure groups. Furthermore, a correlation was also observed between smoking and levels of urinary PAH. We conclude that this radioimmunoassay may be suitable as a simple and sensitive routine assay for monitoring individuals exposed to PAH.

  13. Fasting plasma C-peptide, glucagon stimulated plasma C-peptide, and urinary C-peptide in relation to clinical type of diabetes

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Faber, O K

    1989-01-01

    with a fasting plasma C-peptide value less than 0.20 nmol/l, a glucagon stimulated plasma C-peptide value less than 0.32 nmol/l, and a urinary C-peptide value less than 3.1 nmol/l, or less than 0.54 nmol/mmol creatinine/24 h, or less than 5.4 nmol/24 h mainly were Type 1 diabetic patients; while patients with C...

  14. Specific bile acid radioimmunoassays for separate determinations of unconjugated cholic acid, conjugated cholic acid and conjugated deoxycholic acid in serum and their clinical application

    International Nuclear Information System (INIS)

    Matern, S.; Gerok, W.

    1977-01-01

    Specific radioimmunoassays for separate determinations of serum unconjugated cholic, conjugated cholic and conjugated deoxycholic acids have been developed. Prior to the radioimmunoassay, extraction of serum bile acids was performed with Amberlite XAD-2. Unconjugated cholic acid was separated from glyco- and taurocholic acids by thin-layer chromatography. At 50% displacement of bound labeled glyco[ 3 H]cholic acid using antiserum obtained after immunization with cholic acid-bovine serum albumin-conjugate the cross-reactivity of taurocholic acid was 100%, cholic acid 80%, glycochenodeoxycholic acid 10%, chenodeoxycholic acid 7%, conjugated deoxycholic acid 3%, and conjugated lithocholic acid 3 H]cholic acid was linear on a logit-log plot from 5 to 80 pmol of unlabeled glycocholic acid. Fasting serum conjugated cholic acid in healthy subjects was 0.68 +- 0.34 μmol/l. Unconjugated cholic acid was determined by a solid phase radioimmunoassay using the cholic acid antibody chemically bound to Sepharose. The displacement curve of [ 3 H]cholic acid in the solid phase radioimmunoassay was linear on a logit-log plot from 5 to 200 pmol of unlabeled cholic acid. The coefficient of variation between samples was 5%. Fasting serum conjugated deoxycholic acid concentrations in 10 healthy subjects ranged from 0.18 to 0.92 μmol/l determined by a radioimmunoassay using antiserum obtained after immunization with deoxycholic acid-bovine serum albumin-conjugate. The clinical application of these bile acid radioimmunoassays is shown by an 'oral cholate tolerance test' as a sensitive indicator of liver function and by an 'oral cholyglycine tolerance test' as a useful test for bile acid absorption. (orig.) [de

  15. Radioimmunoassay for biopterin

    International Nuclear Information System (INIS)

    Nagatsu, Toshiharu; Yamaguchi, Tokio; Kato, Takeshi; Sugimoto, Takashi; Matsuura, Sadao.

    1979-01-01

    Specific antibodies against biopterin, neopterin, and 6,7-dimethylpterin were prepared and a new type of radioimmunoassay, to which these pterins were subjected was developed. This new type of radioimmunoassay was used to determine biopterin in human urine. Specific antiserum against biopterin did not crossreact significantly with tetrahydro-biopterin, dihydro-biopterin, neopterin, 6,7-dimethylpterin, pterin, or folic acid and showed 30% binding of biopterinyl-caproyl- ( 125 I ) tyramide at a dilution of 1:800. The antisera against neopterin and dimethylpterin also showed a high specificity and did not cross-react significantly with the other pterins. The sensitivity of the radioimmunoassay was increased about ten-fold by pre-incubating the antiserum with 6,7-dimethylpterinyl-caproyl to remove antibodies against the caproic acid moiety of the biopterin conjugate. The recovery of biopterin or tetrahydro-biopterin added human urine was nearly 100% according to this type of radioimmunoassay, and the biopterin concentrations in the urine that were obtained by means of this type of radioimmunoassay showed a fairly good agreement with the values obtained by means of bioassay. The biopterin contents per milliliter of human urine showed considerable variations depending on the subjects, but those per milligram of creatinine were found to be fairly constant in normal subjects. Therefore, biopterin concentrations per milligram of creatinine in human urine may be a good indicator of biopterin metabolism in clinical chemistry. This new type of radioimmunoassay is simple, highly specific, and reproducible. Therefore, it may be very useful for the screening of atypical phenylketonuria due to biopterin deficiency and also for the study of the pathogenesis of various biopterin metabolic diseases. (J.P.N.)

  16. Radioimmunoassay for biopterin

    Energy Technology Data Exchange (ETDEWEB)

    Nagatsu, T; Yamaguchi, T; Kato, T [Tokyo Inst. of Tech. (Japan); Sugimoto, T; Matsuura, S

    1979-06-01

    Specific antibodies against biopterin, neopterin, and 6,7-dimethylpterin were prepared and a new type of radioimmunoassay, to which these pterins were subjected was developed. This new type of radioimmunoassay was used to determine biopterin in human urine. Specific antiserum against biopterin did not crossreact significantly with tetrahydro-biopterin, dihydro-biopterin, neopterin, 6,7-dimethylpterin, pterin, or folic acid and showed 30% binding of biopterinyl-caproyl- ( /sup 125/I ) tyramide at a dilution of 1:800. The antisera against neopterin and dimethylpterin also showed a high specificity and did not cross-react significantly with the other pterins. The sensitivity of the radioimmunoassay was increased about ten-fold by pre-incubating the antiserum with 6,7-dimethylpterinyl-caproyl to remove antibodies against the caproic acid moiety of the biopterin conjugate. The recovery of biopterin or tetrahydro-biopterin added human urine was nearly 100% according to this type of radioimmunoassay, and the biopterin concentrations in the urine that were obtained by means of this type of radioimmunoassay showed a fairly good agreement with the values obtained by means of bioassay. The biopterin contents per milliliter of human urine showed considerable variations depending on the subjects, but those per milligram of creatinine were found to be fairly constant in normal subjects. Therefore, biopterin concentrations per milligram of creatinine in human urine may be a good indicator of biopterin metabolism in clinical chemistry. This new type of radioimmunoassay is simple, highly specific, and reproducible. Therefore, it may be very useful for the screening of atypical phenylketonuria due to biopterin deficiency and also for the study of the pathogenesis of various biopterin metabolic diseases.

  17. Determination of antibody levels to Candida albicans in healthy and hospitalised adults using a radioimmunoassay

    International Nuclear Information System (INIS)

    Cobb, S.J.; Parratt, D.

    1978-01-01

    A radioimmunoassay for antibody to Candida albicans is described. The test uses whole, killed of organisms as the antigen and radiolabelled sheep anti-human globulins to quantitate different classes of antibody to C. albicans. The assay has been compared with an Ouchterlony precipitin method and found to be simpler, more rapid, and more sensitive than the latter. Results obtained from two groups of symptomless adults indicated that the range of antibody level was wider for a hospitalised group than for a group of blood transfusion donors, particularly in respect of IgG and IgA antibody. The reason for the increase of antibody in hospital patients was not clear but may have been related to antibiotic therapy. The difficulties in interpretation of Candida serology have therefore been re-assessed in the light of more detailed knowledge of the range and type of antibody to be expected in normal individuals. (author)

  18. Validation of a radioimmunoassay for the determination of total corticosterone in rat plasma

    DEFF Research Database (Denmark)

    Pedersen, Tine Karen Hjort

    2000-01-01

    Abstract A radioimmunoassay (RIA) for total corticosterone (CORT) in rat plasma requiring a plasma volume of 2 μl was established. The importance of inactivating plasma corticosteroid-binding globulin (CBG), denatured by heat, before measuring CORT was shown. The method was evaluated and shown...... the blood sampling procedure. The result showed that the method had a capacity to detect CORT concentrations comparable with previous reported basal concentrations. Finally, the possible stress inducing effect of the blood sampling procedure was examined using two groups of male rats housed under either...... conventional or enriched environmental conditions. The result indicated that conventional environment housing induces slightly stressed animals compared to enriched housing. Enriched housing may provide an environment that makes it possible for rats to compensate for a stressful situation, i.e., the blood...

  19. Sensitive radioimmunoassay for the determination of antibodies to mouse hepatitis virus

    Energy Technology Data Exchange (ETDEWEB)

    Leibowitz, J L [California Univ., San Diego, La Jolla (USA); Fung, L S; Levy, G A [Toronto Univ., Ontario (Canada)

    1983-05-01

    A solid-phase radioimmunoassay is described for the detection of antibodies to mouse hepatitis virus. Viruses were purified by velocity and isopycnic gradient centrifugation and 96-well plastic plates were coated with viral antigens. To allow the detection of most serotypes of low titered antisera, a pool of antigens from several viral serotypes were employed. The second antibody, an affinity-purified goat antimouse immunoglobulin, detects IgG, IgM and IgA antibodies. This assay is more sensitive than either the plaque reduction assay or the commercially available enzyme-linked immunosorbant assay and proved to be useful for screening mouse colonies for the presence of mouse hepatitis virus, following seroconversion in experimental animals and in the production of monoclonal antibodies to both structural and nonstructural proteins.

  20. A sensitive radioimmunoassay for the determination of antibodies to mouse hepatitis virus

    International Nuclear Information System (INIS)

    Leibowitz, J.L.; Fung, L.S.; Levy, G.A.

    1983-01-01

    A solid-phase radioimmunoassay is described for the detection of antibodies to mouse hepatitis virus. Viruses were purified by velocity and isopycnic gradient centrifugation and 96-well plastic plates were coated with viral antigens. To allow the detection of most serotypes of low titered antisera, a pool of antigens from several viral serotypes were employed. The second antibody, an affinity-purified goat antimouse immunoglobulin, detects IgG, IgM and IgA antibodies. This assay is more sensitive than either the plaque reduction assay or the commercially available enzyme-linked immunosorbant assay and proved to be useful for screening mouse colonies for the presence of mouse hepatitis virus, following seroconversion in experimental animals and in the production of monoclonal antibodies to both structural and nonstructural proteins. (Auth.)

  1. The Determinations of Estrogen and Progesterone Receptor in Breast Cancer Cell by Radioimmunoassay Method

    International Nuclear Information System (INIS)

    Kim, Chi Yeul

    1981-01-01

    The estrogen and progesterone receptors which are bound to the cytoplasmic protein of cancer cells were measured in 20 patients with the early breast cancer by means of radioimmunoassay using charcoal. 1) The patients with estrogen receptor positive were 13 (65%) of 20 cases and with progestrone receptor positive were 7 cases (35%) in the early breast cancer. 2) Coexistence of estrogen and progesterone receptor positive was noted in 7 cases (35%). The cases of estrogen receptor positive and progesterone receptor negative were 6 cases (33.3%), while there were no cases of estrogen receptor negative with progesterone receptor positive. 3) Coincidence of estrogen and progesterone negative was noticed in 7 cases (35%). Conclusively it is considered that the measurement of estrogen and progesterone receptors has relevance as predictive value, in the response to hormonal manipulations and chemotherapy for breast cancer patients.

  2. C-Peptides for diagnostics and therapy: a veterinary medicine point of view

    Directory of Open Access Journals (Sweden)

    Derek A. Rosenfield

    Full Text Available ABSTRACT: Empirical studies proved that C-peptides are performing numerous intrinsic biological roles, and serve as a marker for pancreatic performance analysis. Since the last decade, C-peptide assays for differential diagnosis in veterinary diabetic patients are becoming more available, but still only for a very limited number of species. Studies on C-peptide as a diagnostic tool, therapy for associated complications, or as replacement therapies for C-peptide deficiency still showed not to be a common practice in veterinary medicine. This review was conducted to determine the potential importance of C-peptide in Veterinary Medicine, relevant in the diagnosis of diabetes and for other metabolic processes, as well as its proposed therapeutic benefits. Numerous articles were identified that reported positive results in their experimental studies, whether C-peptide as a biomarker for pancreatic performance in dogs, cats, and horses, as a non-invasive method to monitor nutritional status in primates, or to investigate its potential therapeutic benefits for diabetes-related illnesses.

  3. Measles and canine distemper virus antibodies in patients with multiple sclerosis determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Arnadottir, T.

    1980-01-01

    Antibodies against measles virus (MV) and canine distemper virus (CDV) were measured by solid-phase radioimmunoassay (RIA) of sera and cerebrospinal fluid (CSF) from 28 patients with multiple sclerosis (MS) and matched neurological controls. When the groups were compared for MV antibody titers and CDV antibody titers of sera and MV/CDV serum antibody titer ratios, no significant difference was found. The CDV antibody titers and the MV antibody titers were in good correlation. CDV antibodies showed RIA titration curves typical of low avidity antibodies. In tests for MV antibodies in CSF, 82% of the MS patients and 19% of the controls were positive, whereas 36% of the MS patients and 4% of the controls were positive in CDV RIA. The correlation between MV and CDV antibody levels, the low avidity of CDV antibodies and the fact that absorption of the specimens with MV antigen abolished all CDV antibody activity suggest that the CDV antibodies are MV antibodies cross-reacting with CDV. It is concluded that canine distemper virus is unlikely to be involved in the etiology of multiple sclerosis. (author)

  4. Heterogeneity of human plasma insulin: techniques for separating immunoreactive components and their determination by radioimmunoassay

    International Nuclear Information System (INIS)

    Souza, Iracelia Torres de Toledo e

    1977-01-01

    When human plasma is filtered on Sephadex G-SO fine, insulin immunoreactivity is recovered in two peaks: 'big insulin', the higher molecular weight component and 'little insulin', the lower molecular component, having elution volumes that correspond to those of porcine proinsulin 125 I and porcine insulin 125 I respectively. The presence of another form of immunoreactive insulin 'big big insulin' was detected from an insuloma suspect and its elution pattern corresponding to serum albumin. The eluates correspondent to 'big' and 'little' insulin as well as 'big big' component were assayed by radioimmunoassay using crystalline human insulin as a standard, porcine insulin 125 tracer and anti insulin serum. The antibody, raised in guinea-pigs, was sensitive and potent being adequate for the assay. The reactivity of insulin and proinsulin was tested against the antibody. The relative proportions of several components of total immunoreactive insulin in plasma were studied in basal conditions in five normal subjects and in the patient JSC with pancreatic insulin-secreting tumor as well as after glucose stimuli in all tolbutamide in JSC. (author)

  5. Liquid phase radioimmunoassay system for determination of progesterone in human serum using different radiolabeled tracers

    International Nuclear Information System (INIS)

    Mehany, N.L.; El-Kolaly, M.T.; Sallam, Kh.M.; EI-Hashash, M.A.

    2007-01-01

    The preparation and development of primary reagents of progesterone radioimmunoassay (R1A) technique with low cost is considered to be the main objective of the present study . The preparation of 125 l-progesterone radiotracers was carried out using chloramine-T, iodogen and lactoperoxidase oxidation methods and they were purified using high perfomance liquid chromatography (HPLC). Tyramine hydrochloride was conjugated with activated progesterone 11α-hemisuccinate and then iodinated using Na 125 I.The tracers obtained were investigated in terms of radiochemical purity, radiochemical yield and immunoreactivity. The production of polyclonal antibodies was undertaken by immunizing six New-Zealand rabbits subcutaneously through primary injection and four booster doses.The preparation of progesterone standards were carried out by preparing stock standard solution of progesterone in ethanol. After evaporation of ethanol, the steroid assay buffer was used as a standard matrix to prepare the working standards required. Optimization and validation of the assay were carried out. The results obtained provide a highly sensitive, specific and accurate RIA system of progesterone based on liquid phase separation. In conclusion, this assay could be used in evaluating corpus luteum insufficiency among women in child bearing period

  6. Immunological half-life of porcine proinsulin C-peptide

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, H; Horino, M; Matsumura, S [Kawasaki Medical Coll., Kurashiki (Japan). Div. of Endocrinology; Kobayshi, K; Suetsugu, N [Yamaguchi Univ., Ube (Japan). School of Medicine

    1975-11-01

    Immunological half-lifes of injected porcine C-peptide and insulin with RIA were studied and calculated as 9.8 and 8.0 minutes. Higher circulating levels of C-peptide as compared to insulin in normal young swines lead to speculation about a longer half-life of C-peptide. This hypothesis was verified in this study. Immunological half-lifes of porcine proinsulin and insulin in the pig were 20 and 6 minutes, respectively.

  7. Influence of C-Peptide on Glucose Utilisation

    Directory of Open Access Journals (Sweden)

    B. Wilhelm

    2008-01-01

    Full Text Available During the recent years, multiple studies demonstrated that C-peptide is not an inert peptide, but exerts important physiological effects. C-peptide binds to cell membranes, stimulates the Na,K-ATPase and the endothelial nitric oxide (NO synthase. Moreover, there is evidence that C-peptide decreases glomerular hyperfiltration and increases glucose utilisation. Nevertheless, there is still limited knowledge concerning mechanisms leading to an increased glucose utilisation either in rats or in humans. The aim of this paper is to give an overview over the published studies regarding C-peptide and glucose metabolism from in vitro studies to longer lasting studies in humans.

  8. Direct determination of free thyroxine in two simultaneous radioimmunoassays with different test principles

    International Nuclear Information System (INIS)

    Lohkamp, F.; Schmidt, M.

    1982-01-01

    Serum FT 4 was measured simultaneously by the commercial FT 4 kits of Amersham-Buchler and Corning Medical in 4 groups with defined thyroid function as follows: 57 euthroid subjects with and without goitre, 27 patients on T 4 supplementation. 12 subjects on oral contraceptives and 26 subclinically hyperthyroid patients. All patients underwent physical examination, thyroid scintigraphy and additional in-vitro tests (total thyroxine T 4 , total triiodothyronine T 3 and TRH/TSH assay). Both assays generally correlated well with the definded thyroid functional status except for the patients on oral contraceptives. Contrary to the FT 4 -test (Amersham-Buchler) in this group the FT 4 -test (Corning Medical) produced a significantly increased mean for FT 4 as compared to the euthyroid group thus indicating a probably insufficient compensation for high but not necessarily abnormal levels of TBG concentration. Using the FT 4 -assay (Amersham-Buchler) the normal range of FT 4 values of euthyroid subjects from the area of Bamberg with marked iodine deficiency agrees well with recently published results of a multicentre trial thus confirming the assumption of serum FT 4 not being strongly dependent on iodine intake. The results of the FT 4 -test (Corning) showed a wider scatter of normal ranges of FT 4 values for all groups and concomitantly reduced discrimination compared to the corresponding simultaneously obtained FT 4 -test (Amersham-Buchler) results. Though cost and time saving, the commercial radioimmunoassays will require further critical evaluation of normal range validity on larger populations of defined abnormalities will require further critical evaluation of normal range validity on larger populations of defined abnormalities of thyroid function to elucidate inherent deficiencies of the new FT 4 methods and of their diagnostic efficiency. (orig./MG) [de

  9. Polyacrylamide gel electrophoretic preparation of labelled and non-labelled peptides for radioimmunoassay

    International Nuclear Information System (INIS)

    Besch, W.; Woltanski, K.P.; Keilacker, H.; Kohnert, K.D.

    1986-01-01

    Radioiodinated polypeptide hormones, such as insulin, glucagon, human growth hormone, and human C-peptide are employed for radioimmunoassays for investigation of hormonal alterations in states of disturbed carbohydrate metabolism. Iodination was performed using chloramine T. Iodination products of these polypeptide hormones and, for preparation of standard material, native human C-peptide from cadaver pancreases were fractionated by polyacrylamide gel electrophoresis at pH 8.9. Disc electrophoresis in 24 cm long gel rods resulted in stable tracers with high specific activity as well as homogeneous standard material being highly suitable for radioimmunoassays. (author)

  10. Radioimmunoassay apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Apparatus for performing a quantitative radioimmunoassay comprising: a substantially spherical bead for carrying an antibody and a gripper for gripping said bead, said gripper comprising an integrally formed unit having a single elongate handle portion and a plurality of resilient fingers arranged at the base of the handle so that when said bead is secured within said fingers, said bead may be freely rotated about any diametric axis of the bead. In particular the invention relates to an apparatus for a two site immunoradiometric assay for serum ferritin in human blood samples. (author)

  11. Canine C-peptide for characterization of experimental diabetes in dogs

    International Nuclear Information System (INIS)

    Fischer, U.; Besch, W.; Freyse, E.-J.

    1985-01-01

    Radioimmunoassay of canine C-peptide (CCP) was developed for the characterization of endogenous beta cell function in experimentally diabetic dogs. The animals were rendered diabetic by subtotal pancreatectomy and intrasurgical infusion of 2 mg/kg streptozotocin into the superior pancreaticoduodenal artery. After an average duration of diabetes of 5 months the animals showed zero peripheral venous fasting CCP levels with no response to feeding, OGTT/i.v. glucagon loading or i.v. glucose tolerance testing. The data on CCP levels entirely coincided with simultaneously measured plasma IRI levels. In non-diabetic control animals clear-cut CCP increases were observed after all stimuli. The experimental model provided an IDDM-type diabetes without toxic symptoms but with a sufficient exocrine pancreatic function. The comparison showed that plasma IRI analyses would also allow reliable characterization of insulinogenic functions in these animals. (author)

  12. Proinsulin C-peptide interferes with insulin fibril formation

    International Nuclear Information System (INIS)

    Landreh, Michael; Stukenborg, Jan-Bernd; Willander, Hanna; Söder, Olle; Johansson, Jan; Jörnvall, Hans

    2012-01-01

    Highlights: ► Insulin and C-peptide can interact under insulin fibril forming conditions. ► C-peptide is incorporated into insulin aggregates and alters aggregation lag time. ► C-peptide changes insulin fibril morphology and affects backbone accessibility. ► C-peptide may be a regulator of fibril formation by β-cell granule proteins. -- Abstract: Insulin aggregation can prevent rapid insulin uptake and cause localized amyloidosis in the treatment of type-1 diabetes. In this study, we investigated the effect of C-peptide, the 31-residue peptide cleaved from proinsulin, on insulin fibrillation at optimal conditions for fibrillation. This is at low pH and high concentration, when the fibrils formed are regular and extended. We report that C-peptide then modulates the insulin aggregation lag time and profoundly changes the fibril appearance, to rounded clumps of short fibrils, which, however, still are Thioflavine T-positive. Electrospray ionization mass spectrometry also indicates that C-peptide interacts with aggregating insulin and is incorporated into the aggregates. Hydrogen/deuterium exchange mass spectrometry further reveals reduced backbone accessibility in insulin aggregates formed in the presence of C-peptide. Combined, these effects are similar to those of C-peptide on islet amyloid polypeptide fibrillation and suggest that C-peptide has a general ability to interact with amyloidogenic proteins from pancreatic β-cell granules. Considering the concentrations, these peptide interactions should be relevant also during physiological secretion, and even so at special sites post-secretory or under insulin treatment conditions in vivo.

  13. Proinsulin C-peptide interferes with insulin fibril formation

    Energy Technology Data Exchange (ETDEWEB)

    Landreh, Michael [Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm (Sweden); Stukenborg, Jan-Bernd [Department of Women' s and Children' s Health, Astrid Lindgren Children' s Hospital, Pediatric Endocrinology Unit, Karolinska Institutet and University Hospital, S-17176 Stockholm (Sweden); Willander, Hanna [KI-Alzheimer' s Disease Research Center, NVS Department, Karolinska Institutet, S-141 86 Stockholm (Sweden); Soeder, Olle [Department of Women' s and Children' s Health, Astrid Lindgren Children' s Hospital, Pediatric Endocrinology Unit, Karolinska Institutet and University Hospital, S-17176 Stockholm (Sweden); Johansson, Jan [KI-Alzheimer' s Disease Research Center, NVS Department, Karolinska Institutet, S-141 86 Stockholm (Sweden); Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-751 23 Uppsala (Sweden); Joernvall, Hans, E-mail: Hans.Jornvall@ki.se [Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm (Sweden)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer Insulin and C-peptide can interact under insulin fibril forming conditions. Black-Right-Pointing-Pointer C-peptide is incorporated into insulin aggregates and alters aggregation lag time. Black-Right-Pointing-Pointer C-peptide changes insulin fibril morphology and affects backbone accessibility. Black-Right-Pointing-Pointer C-peptide may be a regulator of fibril formation by {beta}-cell granule proteins. -- Abstract: Insulin aggregation can prevent rapid insulin uptake and cause localized amyloidosis in the treatment of type-1 diabetes. In this study, we investigated the effect of C-peptide, the 31-residue peptide cleaved from proinsulin, on insulin fibrillation at optimal conditions for fibrillation. This is at low pH and high concentration, when the fibrils formed are regular and extended. We report that C-peptide then modulates the insulin aggregation lag time and profoundly changes the fibril appearance, to rounded clumps of short fibrils, which, however, still are Thioflavine T-positive. Electrospray ionization mass spectrometry also indicates that C-peptide interacts with aggregating insulin and is incorporated into the aggregates. Hydrogen/deuterium exchange mass spectrometry further reveals reduced backbone accessibility in insulin aggregates formed in the presence of C-peptide. Combined, these effects are similar to those of C-peptide on islet amyloid polypeptide fibrillation and suggest that C-peptide has a general ability to interact with amyloidogenic proteins from pancreatic {beta}-cell granules. Considering the concentrations, these peptide interactions should be relevant also during physiological secretion, and even so at special sites post-secretory or under insulin treatment conditions in vivo.

  14. Sensitive radioimmunoassay and enzyme-linked immunosorbent assay for the simultaneous determination of chloroquine and its metabolites in biological fluids

    International Nuclear Information System (INIS)

    Escande, C.; Chevalier, P.; Verdier, F.; Bourdon, R.

    1990-01-01

    Two new methods for the simultaneous determination of chloroquine and its two main metabolites (monodesethylchloroquine and bisdesethylchloroquine) in biological samples, radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA), are described. Antiserum is produced in rabbits immunized with N-(2-carboxyethyl)desethylchloroquine:protein conjugate. Besides chloroquine, this antiserum recognizes with good affinity the two main metabolites, monodesethylchloroquine and bisdesethylchloroquine (70 and 40% of crossreaction, respectively). Amodiaquine cross reacts by 4.5%; cross reactions with monodesethylamodiaquine, bisdesethylamodiaquine, and other antimalarial drugs are less than 1%. No extraction step or sample preparation is required for either system. Sensitivity limits are, respectively, 0.70 nM (3 pg of chloroquine sulfate measured in 10 microL of plasma sample) for RIA, and 10 nM (22 pg of chloroquine sulfate measured in 5 microL of plasma sample) for ELISA. The interassay coefficients of variation are, respectively, less than 10 and less than 16% for RIA and ELISA in the range 14-410 nM (6-180 ng/mL). The results of both methods are well correlated (r = 0.97) and correlate with spectrophotometry (r = 0.98) and HPLC results (r = 0.93). Because of their high sensitivity, both methods can be used in the case of chloroquine poisoning and in the control of malaria prophylaxis and treatment

  15. Measurement of insulin and C-peptide excitatory test levels in gestational diabetes mellitus

    International Nuclear Information System (INIS)

    Du Tongxin; Wang Zizheng

    2001-01-01

    To investigate the function of islet β cells in patients with gestational diabetes mellitus (GDM), serum insulin and C-peptide (C-P) excitatory test levels were measured dynamically by radioimmunoassay in 41 patients with GDM and 30 normal pregnant controls. The results showed that there were significant difference in insulin and C-peptide excitatory test levels between normal pregnancy for 32-40 weeks and patients with GDM (P < 0.001). The secretory peak of insulin occurred at 60 min in normal pregnancy, while at 120 min in patients with GDM, and the recovery postponed in patients with GDM. The peak time for C-P was just as same as that of insulin, but the peak error for C-P between normal pregnant controls and patients with GDM was more larger than that for insulin and it recovered more slowly. It suggested that majority of islet β cells in patients with GDM were good enough for response to islet resistance factors and big stress from pregnancy, and also suggested a relation between pregnancy and islet β cells function

  16. Progesterone radioimmunoassay

    International Nuclear Information System (INIS)

    Allen, R.M.; Redshaw, M.R.

    1981-01-01

    This patent claims a radioimmunoassay for progesterone, which comprises contacting, in an acidic medium a sample of liquid with a predetermined amount of antibodies raised against a progesterone-protein complex, the protein being attached to the 11-position of progesterone by means of a bridging group and with a predetermined amount of a progesterone derivative having an iodinatable group attached to its 3-position by means of a bridging group, the iodinatable group being iodinated with one or more atom(s) of a radioisotope of iodine, separating the steroid bound in the resulting antibody-antigen complex from the free steroid and measuring the radioactivity of the free steroid component or of the antibody-antigen complex. Sufficient sensitivity has been achieved to enable a progesterone assay to be carried out directly on a sample of biological fluid, such as serum, plasma, urine or milk. (U.K.)

  17. A Study of the Insulin and the C-Peptide Responses to Oral Glucose Load in Nondiabetic and Diabetic Subjects

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myung Chul; Choi, Sung Jae; Kim, Eung Jin; Koh, Chang Soon; Min, Hun Ki [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1977-03-15

    The present study was undertaken to evaluate the significance of the insulin and the C-peptide response to oral glucose loads in normal and diabetic subjects and to establish the effects of the obesity. In this study, the authors have measured plasma insulin and C-peptide by means of radioimmunoassay in 10 nonobese normal, 5 obese normal, 13 nonobese moderate diabetic patients, 9 obese moderate diabetic patients and 9 severe diabetic patients. The results obtained were as follows; 1) In 10 nonobese normal subjects, the plasma insulin level at fasting state and at 30, 60, 90, and 120 min after oral glucose loads were 15.7+-3.4, 48.3+-9.8, 40.4+-6.7, 37.4+-6.5 and 26.0+-4.2 uU/ml (Mean+-S.E.) and C-peptide were 1.9+-0.3, 3.9+-0.6, 6.3+-0.6, 5.7+-0.5 and 4.0+-0.5 ng/ml. The change of C-peptide was found to go almost parallel with that of insulin and the insulin value reaches to the highest level at 30 min whereas C-peptide reaches to its peak at 60 min.. 2) The plasma insulin level in 5 obese normal subjects were 38.9+-12.3, 59.5+-12.3, 59.2+-17.1, 56.1+-20.0 and 48.4+-17.2 uU/ml and the C-peptide were 5.5+-0.4, 6.8+-0.5, 7.9+-0.8, 7.9+-0.8 and 7.8+-2.0 ng/ml. The insulin response appeared to be greater than nonobese normal subjects. 3) In 13 nonobese moderate diabetic patients, the plasma insulin levels were 27.1+-4.9, 44.1+-6.0, 37.3+-6.6, 35.5+-8.1 and 34.7+-10.7 uU/ml and the C-peptide levels were 2.7+-0.4, 4.9+-0.7, 6.5+-0.5, 7.0+-0.3 and 6.7+-1.0 ng/ml. There was little significance compared to nonobese normal groups but delayed pattern is noted. 4) In 9 obese moderated diabetic patients, the plasma insulin levels were 22.1+-7.9, 80.0+-19.3, 108.0+-27.0, 62.0+-17.6 and 55.5+-10.l uU/ml and the C-peptide levels were 5.2+-0.4, 8.0+-1.0, 10.4+-1.6, 10.4+-1.7 and 10.1+-1.0 ng/ml and its response was also greater than that of nonobese moderate diabetic patients. 5) The plasma insulin concentrations in 9 severe diabetic subjects were 8.0+-3.8, 12.1+-3.5, 16.8+-4.6, 19

  18. Determination of total bile acids in serum. A comparison of a radioimmunoassay with an enzymatic-fluorimetric method

    International Nuclear Information System (INIS)

    Starkey, B.J.; Marks, V.

    1982-01-01

    A solid phase radioimmunoassay kit method for total conjugated bile acids has been compared to an enzymatic fluorimetric method for total serum bile acids. The methods were compared with respect to: precision, cross-reactivity (molar equivalence) of different bile salts, recovery of different bile salts from serum, the reference range for a healthy population, linearity, coefficient of correlation, diagnostic effectiveness, cost and ease of assay. Both assays seemed equally capable of predicting the presence or absence of liver disease. Radioimmunoassay had little advantage over the enzymatic-fluorimetric method. Its relative ease was far outweighed by its greater cost and poorer analytical performance. (Auth.)

  19. Kinetics of circulating endogenous insulin, C-peptide, and proinsulin in fasting nondiabetic man

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Tronier, B; Bülow, J B

    1987-01-01

    Plasma concentrations of insulin, C-peptide, and proinsulin were measured in different vascular beds in order to determine renal, hepatic, and systemic kinetics of the endogenous peptides in the fasting condition. Nineteen nondiabetic subjects were studied, two were normal, nine had minor vascular...

  20. Studies on local preparation of double antibody radioimmunoassay for determination of alpha fetoprotein as a tumor marker

    International Nuclear Information System (INIS)

    Elkolaly, M.T.; Mehany, N.L.; Ragab, M.T.; El-Mohty, A.A.

    2001-01-01

    The preparation of primary reagents of AFP- RIA technique with low cost is considered to be one of the main objective of labelled compounds Dept., Radioisotope production Division, Hot Labs Centre, Atomic Energy Authority, Egypt. The development of a radioimmunoassay system based on local production of basic reagents for the measurement of AFP in human serum is described. The assay followed by 100 μ1 of locally prepared 125 I-AFP to 100 μ1 standards and unknown samples. After overnight incubation at 4 degree, separating reagents were added in following sequence 100 μ1 non-immune rabbit serum (1:200) followed by addition of 100μ1 of donkey anti-rabbit serum, (1:20), then 500μ1 of 8 percentage polyethylene glycol (PEG) were added into all assay tubes. The tubes were allowed to stand for 30 minutes at room temperature and then centrifuged for 15 minutes. the tubes were decanted and counted in a gamma counter. The results of the present study showed that the assay is highly sensitive where the detection limit or minimal detectable dose of AFP assay approximately 1.5 I U/ml. The reliability of the present procedure was assessed by examining its reproducibility on pooled human serum samples selected to represent different levels of AFP. The data of intra-assay and intra-assay precision revealed the consistency of the results obtained by the method of the present study. The present technique for determination of serum AFP agreed well with commercially available kits (DPC, double antibody-diagnostic product corporation, los angeles, USA). The technical simplicity of this specific, accurate and reasonably precise method may suggest that the technique should be suited for routine laboratory use

  1. Radioimmunoassay in clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Ametov, A S

    1982-01-01

    A wide application of radioimmunoassay in clinical practice is shown. The main theoretical aspects of radioimmunoassay and the fields of application in clinical practice - endocrinology, oncology, allergology, cardiology, pharmacology, pediatrics, hematology, obstetrics and gynecology, are presented.

  2. Steroid radioimmunoassays

    International Nuclear Information System (INIS)

    Shinde, Y.; Hacker, R.R.; Ntunde, B.; Smith, V.G.

    1981-01-01

    An estrogen radioimmunoassay was used to study the problem of blanks in steroid assays. Negligible binding (1.5 percent) in the non-antibody tubes prevailed throughout the study. The assay was validated using accepted procedures. Both water and solvent blanks had estrogen concentrations of 7-9 pg/tube. However, neither water nor solvent blanks showed a dose-related response, indicating that they were 'real' blanks. Exogenous estradiol, when added to water and solvent in quantities less than the estimated blank, was not quantitatively recovered. However, exogenous estradiol added to the water solvent in quantities greater than the blank estimate was quantitatively recovered. The sensitivity of the reference standard curve was 6-10 pg/tube, approximately the same as the blank estimate. These results indicated that the estimates of water and solvent blanks were measures of the assay sensitivity. In such circumstances, it is suggested that blank estimates should not be subtracted from sample values. If the blank estimates are high, attention should be directed towards improving the sensitivity of the assay

  3. Radioimmunoassay and chemical ionization/mass spectrometry compared for plasma cortisol determination

    International Nuclear Information System (INIS)

    Lindberg, C.; Johnson, S.; Hedner, P.; Gustafsson, A.

    1982-01-01

    A method is described for determination of cortisol in plasma and urine, based on chemical ionization/mass spectrometry with deuterium-labeled cortisol as the internal standard. The within-run precision (CV) was 2.5-5.7%, the between-run precision 4.6%. Results by this method were compared with those by a radioimmunological method (RIANEN Cortisol, New England Nuclear) for 395 plasma samples. The latter method gave significantly higher (approx. 25%) cortisol values

  4. Radioimmunoassay in microtiter plates

    International Nuclear Information System (INIS)

    Hirschberg, T.; Hirschberg, H.

    1987-01-01

    A radioimmunoassay was performed in the wells of casein-coated microplates employing 125 I-labelled sheep anti-human second antibody. The antigen-antibody complexes were thereafter dislodged from the well walls using detergent sodium dodecyl sulfate (SDS) and the entire contents of the wells were simultaneously absorbed into 48 cellulose acetate-absorbing cartridges. All 48 cartridges were transferred to counting vials and the radioactivity determined by standard gamma counting techniques. The particular advantage of the method described here is the ease with which the supernatants can be collected and transferred to counting vials with minimal handling of radioactive samples. 6 refs.; 1 figure; 1 table

  5. Peptide radioimmunoassays in clinical medicine

    International Nuclear Information System (INIS)

    Geokas, M.C.; Yalow, R.S.; Straus, E.W.; Gold, E.M.

    1982-01-01

    The radioimmunoassay technique, first developed for the determination of hormones, has been applied to many substances of biologic interest by clinical and research laboratories around the world. It has had an enormous effect in medicine and biology as a diagnostic tool, a guide to therapy, and a probe for the fine structure of biologic systems. For instance, the assays of insulin, gastrin, secretin, prolactin, and certain tissue-specific enzymes have been invaluable in patient care. Further refinements of current methods, as well as the emergence of new immunoassay techniques, are expected to enhance precision, specificity, reliability, and convenience of the radioimmunoassay in both clinical and research laboratories

  6. Changes in pancreatic somatostatin content in spontaneously diabetic mice, as determined by radioimmunoassay and immunohistochemical methods

    International Nuclear Information System (INIS)

    Makino, H.; Matsushima, Y.; Kanatsuka, A.; Yamamoto, M.; Kumagai, A.; Nishimura, M.

    1979-01-01

    A specific RIA for somatostatin (SRIF) was used to determine the SRIF content of the pancreas and hypothalamus in spontaneously diabetic C57BL/KsJ dbdb and C57BL/6J obob mice. In addition, SRIF- and glucagon-containing cells were examined in the pancreatic islets with an immunohistochemical technique. In dbdb mice, immunoassayable pancreatic SRIF content was increased, as was the number of SRIF- or glucagon-containing cells. In obob mice, immunoassayable pancreatic SRIF content was also increased, but no increase was noted in the number of SRIF- or glucagon-containing cells. The hypothalamic SRIF content of either strain was not different from that of controls. These results regarding pancreatic SRIF content were in accord with some but not all previous reports. These differences may be related to the age of the mice or to the conditions in which they were bred. The pancreatic SRIF increase in both dbdb and obob mice may be attributable to hyperglucagonemia, hyperglycemia, or a decrease in insulin action. Further work is necessary to clearly delineate the mechanism

  7. Handbook of radioimmunoassay

    International Nuclear Information System (INIS)

    Abraham, G.E.

    1977-01-01

    This handbook provides clear, detailed descriptions of ways to set up radioimmunoassay procedures for a variety of polypeptides and low molecular weight compounds. It covers extensively the subjects of statistical evaluation of radioimmunoassay, instrumentation in radioimmunoassay, and radiation safety in the performance of radioimmunoassay. Related nonconventional methods are also discussed. Contributors to this handbook have presented their own procedures for performing the radioimmunoassay and their rationale for choosing particular reagents and conditions. Emphasis is on providing sufficient information to enable relatively inexperienced immunoassayists to set up assay systems with a minimum of difficulty

  8. Radioimmunoassay reagent and its use in a radioimmunoassay

    International Nuclear Information System (INIS)

    Polito, A.J.; Knight, W.S.

    1977-01-01

    A radioimmunoassay to detect or determine a steroid of the cortisone and aldosterone group has been developed. The invention particularly concerns a steroid derivative containing imidazole group which is radioactively labelled. The invented reagents are labelled with iodine 125. (VJ) [de

  9. Quantitative determination of the organ distribution of the cell adhesion molecule cell-CAM 105 by radioimmunoassay

    International Nuclear Information System (INIS)

    Odin, P.; Oebrink, B.

    1987-01-01

    The authors have previously identified a 105,000-Da plasma membrane glycoprotein, denoted cell-CAM 105, that is involved in intercellular adhesion of reaggregating rat hepatocytes. In this communication they report on the development of a radioimmunoassay for cell-CAM 105, employing purified cell-CAM 105, specific antisera against the molecule, and formalin-fixed protein A-containing staphylococci for precipitation of the immune complexes. The assay was shown to be sensitive, specific, precise, rapid, and easy to perform. They used this radioimmunoassay in investigations of the occurrence of cell-CAM 105 in different rat organs. Cell-CAM 105 was present in a wide spectrum of organs in varying amounts. The highest concentrations were found in the gastrointestinal tract, liver, some secretory glands, vagina, kidney, and lung. The results were confirmed by immunoblotting, which revealed one distinct protein component, corresponding to cell-CAM 105, in each positive organ

  10. Measurement of antibodies to tubulin by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Mead, G M; Cowin, P; Whitehouse, J M.A. [CRC Medical Oncology Unit, Southampton General Hospital, Southampton, U.K.

    1979-07-24

    A solid-phase double antibody radioimmunoassay capable of measuring antibody to tubulin, the principal component of microtubules, is described. This assay is simple, combining sensitivity with specificity and also allowing determination of antibody subclasses.

  11. DNA methylation mediates the effect of maternal cognitive appraisal of a disaster in pregnancy on the child's C-peptide secretion in adolescence: Project Ice Storm.

    Directory of Open Access Journals (Sweden)

    Lei Cao-Lei

    Full Text Available Animal and human studies suggest that prenatal exposure to stress is associated with adverse health outcomes such as type 2 diabetes. Epigenetic modification, such as DNA methylation, is considered one possible underlying mechanism. The 1998 Quebec ice storm provides a unique opportunity to study an independent prenatal stressor on child outcomes. C-peptide is the best measure of endogenous insulin secretion and is widely used in the clinical management of patients with diabetes. The objectives of this study are to determine 1 the extent to which prenatal exposure to disaster-related stress (maternal objective hardship and maternal cognitive appraisal influences children's C-peptide secretion, and 2 whether DNA methylation of diabetes-related genes mediates the effects of prenatal stress on C-peptide secretion. Children's (n = 30 C-peptide secretion in response to an oral glucose tolerance test were assessed in blood at 13½ years. DNA methylation levels of selected type 1 and 2 diabetes-related genes were chosen based upon the genes associated with prenatal maternal objective hardship and/or cognitive appraisal levels. Bootstrapping analyses were performed to determine the mediation effect of DNA methylation. We found that children whose mothers experienced higher objective hardship exhibited higher C-peptide secretion. Cognitive appraisal was not directly associated with C-peptide secretion. DNA methylation of diabetes-related genes had a positive mediation effect of objective hardship on C-peptide secretion: higher objective hardship predicted higher C-peptide secretion through DNA methylation. Negative mediation effects of cognitive appraisal were observed: negative cognitive appraisal predicted higher C-peptide secretion through DNA methylation. However, only one gene, LTA, remained a significant mediator of cognitive appraisal on C-peptide secretion after the conservative Bonferroni multiple corrections. Our findings suggest that DNA

  12. Levels of human and rat hypothalamic growth hormone-releasing factor as determined by specific radioimmunoassay systems

    International Nuclear Information System (INIS)

    Audhya, T.; Manzione, M.M.; Nakane, T.; Kanie, N.; Passarelli, J.; Russo, M.; Hollander, C.S.

    1985-01-01

    Polyclonal antibodies to synthetic human pancreatic growth hormone-releasing factor [hpGRF(1-44)NH 2 ] and rat hypothalamic growth hormone-releasing factor [rhGRF(1-43)OH] were produced in rabbits. A subsequent booster injection by the conventional intramuscular route resulted in high-titer antibodies, which at a 1:20,000 dilution were used to develop highly sensitive and specific radioimmunoassays for these peptides. The antibody to hpGRF(1-44)NH 2 is directed against the COOH-terminal region of the molecule, as shown by its cross reactivity with various hpGRF analogues. Serial dilutions of human and rat hypothalamic extracts demonstrated parallelism with the corresponding species-specific standard and 125 I-labeled tracer. There was no cross reactivity with other neuropeptides, gastrointestinal peptides, or hypothalamic extracts of other species. Age-related changes in hypothalamic GRF content were present in rats, with a gradual increase from 2 to 16 weeks and a correlation between increasing body weight and GRF content. These radioimmunoassays will serve as important tools for understanding the regulation of growth hormone secretion in both human and rat

  13. An assessment of radioimmunoassay procedures for determination of anti-acetylcholine receptor antibodies in the sera of patients with myasthenia gravis

    International Nuclear Information System (INIS)

    Carter, B.; Harrison, R.; Lunt, G.G.; Morris, H.; Savage-Marengo, T.; Stephenson, F.A.

    1981-01-01

    A reproducible radioimmunoassay procedure for the determination of anti-acetylcholine receptor antibodies in the sera of patients with myasthenia gravis is described and examined in detail. The assay combines features of a number of methods previously outlined and allows repeat determinations of antibody titre in a given myasthenic serum sample with coefficient of variation 6%. The mean +- standard deviation for normal human serum anti-acetylcholine receptor antibodies was found by this procedure to be 0.024 +- 0.033 nmol/l α-bungarotoxin binding sites whereas the range for myasthenic patients was 0-139.14 nmol/l with a mean value of 7.55 nmol/l α-bungarotoxin binding sites. (author)

  14. Setting-up and validation of two radioimmunoassay methods for determination of plasma progesterone concentration in mares, cows and rats

    International Nuclear Information System (INIS)

    Rosa e Silva, A.A.M.; Caldas, M.C.S.; Campos, L.M.A.; Gradela, A.

    1993-01-01

    Two reliable radioimmunoassay (RIA) methods which permits the measurement of progesterone (P 4 ) in plasma of equine, bovine and rats are described. After extraction of plasma with diethylic ether the RIA methods were performed. The first one utilizes 125 I progesterone (double antibody method) and the other 1,2,6,7,16, 17 3 H progesterone (adsorption in charcoal/dextran). Both two methods were suitable in the valuation of plasma P 4 concentration in different physiological reproductive conditions. The method of the double antibody showed higher sensibility beyond to be less expensive than the other method. Despite it, the two RIA methods were much less expensive than available commercial Kits in the market. (author)

  15. Radioimmunoassay for determination of blood aldosterone and renin in the diagnosis of some forms of arterial hypertension

    International Nuclear Information System (INIS)

    Khamidov, R.I.; Khalmuratova, R.A.; Sattarova, F.K.

    1987-01-01

    Aldosterone concentration and renin activity in the blood from the ulnar, inferior cava veins at the level of the 12th thoracic vertebra, the left and right renal veins were studied in 60 patients with arterial hypertension by means of a radioimmunoassay kits (France). The patients were divided into 4 groups: with primary and idiopathic hyperaldosteronism, renal-parenchymatous and essential arterial hypertension. The diagnosis of primary and idiopathic hyperaldosteronism was also confirmed by low blood renin activity. Renin activity in the peripheral venous blood was considerably elevated in renal-parenchymatous arterial hypertension and was normal in essential hypertension. Aldosterone concentration in the blood from the vena cava inferior and renal veins was 1.6-2-fold as high on the affected side as on the contralateral one

  16. Radioimmunoassay of anabolic steroids

    International Nuclear Information System (INIS)

    Hampl, R.; Stranska, I.; Starka, L.; Picha, J.; Chundela, B.

    1978-01-01

    Alternative antisera against 17 α-methyltestosterone and 19-nortestosterone were raised and used for radioimmunoassay of anabolic steroids. Tritiated compounds were used as radioligands. The RIA method suitable for doping control is proposed for 17 α-alkylated anabolic steroids in both plasma and urine, using qoat antiserum against methyltestosterone-3-carboxymethyloxime-BSA. Sensitivity of the method was expressed as least amount of nonradioactive methandienone which, when added to normal urine or plasma, caused statistically significant decrease of measured supernatant radioactivity at 99% level. The amounts from 50 to 500 pg were tested, each in eight parallel determinations. The amounts of 100 pg for plasma and 200 pg for urine met these criteria. The respective coefficients of variation did not depend on the amount of steroid added in this range. They averaged 4.60% for plasma and 4.95% for urine, respectively. (T.I.)

  17. Delta antibody radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Urbankova, J

    1985-11-15

    The principle and procedure are described of the radioimmunoassay of delta antibody (delta-Ab) using the ABBOTT ANTI-DELTA kit by Abbott Co. A description is given of the kit, the working procedure and the method of evaluation. The results are reported of the incidence of delta-Ab in sera of patients with viral hepatitis B, in haemophiliacs, carriers of the hepatitis B virus surface antigen (HBsAg) and blood donors. The presence was detected of delta-Ab in one HBsAg carrier. The necessity is emphasized of delta-Ab determinations in the blood of donors in view of the antibody transfer with blood and blood preparations.

  18. Radioimmunoassay of erythropoietin

    Energy Technology Data Exchange (ETDEWEB)

    Goldwasser, E; Sherwood, J B [Chicago Univ., IL (USA). Dept. of Biochemistry

    1981-07-01

    A brief review of the historical development of the radioimmunoassay (RIA) for serum erythropoietin is given. It has been shown that there is reasonable agreement between the results obtained by RIA and those obtained by the previously used bioassay. By RIA, a mean normal serum titre of 18 mu/ml erythropoietin has been determined in a study of 445 individuals. Serum erythropoietin results for patients with polycythaemia vera have not been shown to be significantly different from normal values but in patients with secondary polycythaemia, serum titres averaging 94 mu/ml have been found. The predicted physiological changes in erythropoietin titre have also been demonstrated in humans using the RIA; increasing after bleeding and decreasing after red cell administration. Studies of erythropoietin levels in experimental animals have shown that, with the particular antiserum used, the sensitivity of the RIA is markedly reduced.

  19. Importance of radioimmunoassay of insulin secretion disorder as atherogenic factor

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, Yu A; Bespalova, V A; Vakhrusheva, L L; Kirbasova, N P; Severtseva, V V

    1984-11-01

    Using a radioimmunoassay a C-peptide levei was revealed in children, pregnant and lying-in women as well as in patients with insulin-dependent diabetes mellitus. After breakfast and insulin administration wich curative purposes the IRI concentration in children increased whereas the C-peptide level changed insignificantly. Changes of the insulin secretion were more noticeable in severe diabetes mejlitus with vascular complications and in disease decompensation. The atherogenic nature of the lipid metaboiism (an increase in the cholesterol, triglyceride and ..beta..-lipoprotein levels), changes in the liver and tendency to vascular involvement are results of insulin effect inadequacy. Such metabolic derangements in pregnant women create unfavorable conditions for the development of fetus and may lead to early atherogenic processes.

  20. Progesterone radioimmunoassay

    International Nuclear Information System (INIS)

    Stroufova, A.; Kozlova, J.

    1976-01-01

    RIA methods of determining progestorone using the SORIN kit made in Italy and the NEN kit made in Great Britain were compared. Plasma extraction, the initial sample size for examination and recovery, the range of calibration curves of the two kits, the variation coefficient, the values of the blank sample and the values of progesterone determined in the normal menstrual cycle are discussed in detail. Variation coefficient: Sorin (calibration curve 9 to 11%, biological material 9.2%), NEN (calibration curve 12%, biological material 27.8%); determinations of progesterone levels during a normal menstrual cycle were 10 to 15% higher with the NEN kit; tritiated samples were measured with a 30 to 37% efficiency using the SORIN kit and 15 to 18% efficiency using the NEN kit. The turbidity and later sediment which formed during the determination of steroid hormones in biological materials after the addition of the scintillation solution did not reduce the efficiency of measurement. Priority is given to the SORIN kit. (L.O.)

  1. Immunochemical heterogeneity of calcitonin in man: effect on radioimmunoassay

    International Nuclear Information System (INIS)

    Snider, R.H.; Moore, C.F.

    1977-01-01

    Determinations of blood levels of human calcitonin by radioimmunoassay have varied considerably in different laboratories. Much of the controversy over calcitonin levels can be attributed to the multiplicity of immunoreactive forms of the hormone (iCT), the differing region specificities of the antisera utilized for measurement by radioimmunoassay, protein effects, different rates of degradation of the various iCT fractions and the specific methodology of the radioimmunoassay

  2. Correlations between fasting plasma C-peptide, glucagon-stimulated plasma C-peptide, and urinary C-peptide in insulin-treated diabetics

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Frøland, A

    1987-01-01

    This study correlated fasting plasma C-peptide (CP), plasma CP 6 min after stimulation with 1 mg glucagon i.v., and the mean of three 24-h urinary excretions of C-peptide (UCP)/creatinine in 132 insulin-treated diabetics. Patients were divided into three groups: group 1, stimulated CP less than 0.......06 nM (n = 51); group 2, stimulated CP 0.06-0.60 nM (n = 48); and group 3, stimulated CP greater than 0.60 nM (n = 33). In all patients fasting CP was closely correlated to stimulated CP (r = .988, P less than .001), whereas the correlations between UCP and both fasting CP (r = .904, P less than .001......) and stimulated CP r = .902, P less than .001) were slightly less pronounced. The associations between UCP and both fasting CP (r = .716, P less than .001) and stimulated CP (r = .731, P less than .001) were modest in group 2, and even more so in group 3 (r = .557, P less than .001 and r = .641, P less than .001...

  3. Study on the determination of human placental lactogen (HPL) using an enzyme-immunoassay. Comparison with a commercial radio-immunoassay in the course of normal pregnancies

    International Nuclear Information System (INIS)

    Schneider, B.

    1982-01-01

    A novel enzyme-immunoassay (EIA) for determining human placental lactogen (HPL) was studied for its practicability and quality. The precision of the system in series was tested by using a serum taken each in the 19th, 29th and 40th pregnancy week. A normal range graph between the 10th and the 40th pregnancy week (10 sera per pregnancy week) was established from 310 sera of normal-course pregnancies. The graph practically agreed with the known RIA-established graphs. When comparing with a radio-immunoassay for HPL of routine application and known quality criteria, r=0.93 indicated a close correlation of the values found. (orig./MG) [de

  4. Determination by radioimmunoassay of the sum of oxidized and reduced forms of NAD and NADP in picomole quantities from the same acid extract

    International Nuclear Information System (INIS)

    Bredehorst, R.; Lengyel, H.; Hilz, H.

    1979-01-01

    The sum of the amounts of NAD + NADH was determined from the same acid tissue extract with the aid of a highly specific radioimmunoassay for 5'-AMP. NAD was converted to 5'-AMP via ADP-ribose by alkaline treatment while NADH was converted first to ADP-ribose by incubation of the acid extract at 25 0 C followed by alkaline conversion to 5'-AMP. Removal of phosphate groups in NADP and NADPH by treatment of the extracts with alkaline phosphates extended the procedure to the quantification of NADP(H). When combined with enzymic analyses of the oxidized coenzyme forms, NAD/NADH and NADP/NADPH ratios could also be obtained from the same extracts. The sensitivity of the test allows quantification of pyridine nucleotides in the range of 0.1-10 pmol. (orig.)

  5. Elastic fibers in human skin: quantitation of elastic fibers by computerized digital image analyses and determination of elastin by radioimmunoassay of desmosine.

    Science.gov (United States)

    Uitto, J; Paul, J L; Brockley, K; Pearce, R H; Clark, J G

    1983-10-01

    The elastic fibers in the skin and other organs can be affected in several disease processes. In this study, we have developed morphometric techniques that allow accurate quantitation of the elastic fibers in punch biopsy specimens of skin. In this procedure, the elastic fibers, visualized by elastin-specific stains, are examined through a camera unit attached to the microscope. The black and white images sensing various gray levels are then converted to binary images after selecting a threshold with an analog threshold selection device. The binary images are digitized and the data analyzed by a computer program designed to express the properties of the image, thus allowing determination of the volume fraction occupied by the elastic fibers. As an independent measure of the elastic fibers, alternate tissue sections were used for assay of desmosine, an elastin-specific cross-link compound, by a radioimmunoassay. The clinical applicability of the computerized morphometric analyses was tested by examining the elastic fibers in the skin of five patients with pseudoxanthoma elasticum or Buschke-Ollendorff syndrome. In the skin of 10 healthy control subjects, the elastic fibers occupied 2.1 +/- 1.1% (mean +/- SD) of the dermis. The volume fractions occupied by the elastic fibers in the lesions of pseudoxanthoma elasticum or Buschke-Ollendorff syndrome were increased as much as 6-fold, whereas the values in the unaffected areas of the skin in the same patients were within normal limits. A significant correlation between the volume fraction of elastic fibers, determined by computerized morphometric analyses, and the concentration of desmosine, quantitated by radioimmunoassay, was noted in the total material. These results demonstrate that computerized morphometric techniques are helpful in characterizing disease processes affecting skin. This methodology should also be applicable to other tissues that contain elastic fibers and that are affected in various heritable and

  6. Radioimmunoassay for plasma renin activity

    International Nuclear Information System (INIS)

    1975-01-01

    A radioimmunoassay for the determination of renin activity in blood plasma is described. The plasma sample is mixed with a generator buffer solution also containing an inhibitor for enzymes which convert angiotensin I into other substances. The renin in the plasma sample converts angiotensinogen into angiotensin I. The amount of angiotensin I is then measured with a competitive binding method using 125 I-labelled angiotensin I and antibodies to angiotensin I

  7. Radioimmunoassays of papain in beer

    International Nuclear Information System (INIS)

    Rauch, P.; Fukal, L.; Strejcek, F.; Kas, J.

    1984-01-01

    A radioimmunoassay (RIA) of papain is described which is capable of detecting 0.2 μg of papain/ml in beer, a level approximately 1% of that normally used for chillproofing. Changes in incubation conditions significantly accelerate the papain determination with only slight loss of accuracy. Apart from the high sensitivity it has been shown that the method is highly specific and distinguishes papain from the other chillproofing enzymes used. (author)

  8. A sensitive radioimmunoassay for fentanyl

    International Nuclear Information System (INIS)

    Michiels, M.; Hendriks, R.; Heykants, J.

    1977-01-01

    Antiserum to fentanyl was obtained in rabbits repeatedly injected with carboxyfentanyl conjugated to bovine serum albumin. Using the antiserum, a highly sensitive radioimmunoassay has been developed, based on the dextran-coated charcoal method. It proved possible to assay the drug directly in plasma, in amounts as small as 30 picogram in 0.5 ml. The antibody was highly specific for fentanyl and no cross-reaction was observed with its major metabolites. This sensitive and specific radioimmunoassay method was employed to determine fentanyl in plasma from six volunteers after an intravenous bolus of 0.2 mg, and in plasma from dogs treated both intravenously and subcutaneously with 0.02 mg/kg. The plasma level of fentanyl could be followed for up to 6 h after a therapeutic dose in dogs and man. (orig.) [de

  9. Preparation Of Liquid Phase-Double Antibodies Radioimmunoassay For The In Vitro Determination Of Prolactin Hormone In Human Serum

    International Nuclear Information System (INIS)

    MEHANY, N.L.; EL-KOLALY, M.T.; EBEID, N.H.; MEKY, N.H.

    2009-01-01

    In the present study, the preparation of the basic reagents of prolactin (PRL) radioimmunoassay (RIA) technique using liquid phase double antibody with low cost is considered to be the main objective. Three primary components were prepared and characterized to obtain valid and accurate system. These components were polyclonal antibody (anti-PRL), 125 I-prolactin ( 125 I-PRL) radio-iodinated tracer and PRL standards. The production of polyclonal anti-PRL was undertaken by immunizing eight males of white New-Zealand rabbits (two groups) with highly purified PRL antigen through primary injection and five booster doses subcutaneously and intramuscular. The preparation of radio-iodinated ( 1 '2 5 I-PRL) tracer was carried out using chloramine-T method. The preparation of PRL standards were carried out using highly purified PRL antigen in assay buffer. The obtained PRL-antisera were characterized in terms of titer, immuno response and displacement profile. Formulation, optimization and validation of the local liquid phase RIA system were carried out. The results obtained provide a highly sensitive, specific and accurate RIA system of PRL. In conclusion, this technique could be used in diagnosis of pituitary dysfunction such as hyperprolactinaemia and hyperprolactinaemia, prolactinoma, galactorrhoea, amenorrhea and diagnosis of infertility in males and females.

  10. Application of Magnetizable Cellulose Particles in Radioimmunoassay for In-Vitro Determination of Follicle Stimulating Hormone in Human Serum

    International Nuclear Information System (INIS)

    Ebeid, N.H.; El-Bayoumy, A.S.A.

    2017-01-01

    The measurement of Follicle Stimulating Hormone ( FSH) in human serum is essential for investigating fertility and especially disorders of the hypothalamic pituitary gonadal axis. Therefore, the present study aimed to prepare radioimmunoassay (RIA) system using solid phase magnetic particles for the in-vitro quantitative measurement of FSH in human serum. The preparation of polyclonal antibody (anti-FSH), "1"2"5I-FSH tracer and FSH standards was carried out. The activation of magnetic particles using 1, /1-carbonyl diimidazole (CDI) and coupling of activated particles with purified anti-FSH were carried out. Optimization and validation of the assay were undertaken. The reproducibility as measured by the intra-and inter-assay variations is acceptable. The recovery and dilution tests indicated accurate calibration and appropriate matrix. The present technique is in a good agreement well with the currently used commercial kit (Izotop, IRMA). The magnetic particles of the present system for estimation of FSH retain their characteristics during storage for 12 months at 4 °C. It can be concluded that this technique proved to be sensitive, specific, precise and accurate for routine laboratory use

  11. Determination of serum progesterone by radioimmunoassay (RIA) on fertility control and early pregnancy diagnosis in angora goats

    International Nuclear Information System (INIS)

    Ozsar, S.; Guven, B.; Ozekin, N.; Noyan, A.

    1984-01-01

    This study was undertaken to provide information on diagnosis of cyclicity, confirmation of estrus so that mating timing and confirmation of return on non-return (pregnancy diagnosis) in Angora goats by using progesterone radioimmunoassay (RIA) in serum as well as observing the sexual behaviours of the goats. The cyclic reproductive activity of 20 mature Angora goat does with normal previous reproductive function, 5 does which had never become pregnant in the previous breeding seasons, and 10 does which were old for breeding was investigated. Circulating progesterone was relatively low (0.45 ng/ml) at estrus (day 0) and increased progressively to 3.45 ng/ml during the subsequent luteal phase. This high level was maintained until day-3 of the succeding estrus cycle, when it decreased abruptly. Pregnancy diagnosis based on the levels of progesterone in serum was confirmed by kidding. 1.5 ng/ml or more progesterone was used as an indication of pregnancy (within 21 days after mating). The accuracy of pregnancy by progesterone assay was 100%. It was concluded that the use of progesterone RIA in serum is a reliable and convenient means of monitoring ovarian activity and early pregnancy. (author)

  12. A Study of the Insulin and the C-Peptide Responses to Oral Glucose Load in Nondiabetic and Diabetic Subjects

    International Nuclear Information System (INIS)

    Lee, Myung Chul; Choi, Sung Jae; Kim, Eung Jin; Koh, Chang Soon; Min, Hun Ki

    1977-01-01

    The present study was undertaken to evaluate the significance of the insulin and the C-peptide response to oral glucose loads in normal and diabetic subjects and to establish the effects of the obesity. In this study, the authors have measured plasma insulin and C-peptide by means of radioimmunoassay in 10 nonobese normal, 5 obese normal, 13 nonobese moderate diabetic patients, 9 obese moderate diabetic patients and 9 severe diabetic patients. The results obtained were as follows; 1) In 10 nonobese normal subjects, the plasma insulin level at fasting state and at 30, 60, 90, and 120 min after oral glucose loads were 15.7±3.4, 48.3±9.8, 40.4±6.7, 37.4±6.5 and 26.0±4.2 uU/ml (Mean±S.E.) and C-peptide were 1.9±0.3, 3.9±0.6, 6.3±0.6, 5.7±0.5 and 4.0±0.5 ng/ml. The change of C-peptide was found to go almost parallel with that of insulin and the insulin value reaches to the highest level at 30 min whereas C-peptide reaches to its peak at 60 min.. 2) The plasma insulin level in 5 obese normal subjects were 38.9±12.3, 59.5±12.3, 59.2±17.1, 56.1±20.0 and 48.4±17.2 uU/ml and the C-peptide were 5.5±0.4, 6.8±0.5, 7.9±0.8, 7.9±0.8 and 7.8±2.0 ng/ml. The insulin response appeared to be greater than nonobese normal subjects. 3) In 13 nonobese moderate diabetic patients, the plasma insulin levels were 27.1±4.9, 44.1±6.0, 37.3±6.6, 35.5±8.1 and 34.7±10.7 uU/ml and the C-peptide levels were 2.7±0.4, 4.9±0.7, 6.5±0.5, 7.0±0.3 and 6.7±1.0 ng/ml. There was little significance compared to nonobese normal groups but delayed pattern is noted. 4) In 9 obese moderated diabetic patients, the plasma insulin levels were 22.1±7.9, 80.0±19.3, 108.0±27.0, 62.0±17.6 and 55.5±10.l uU/ml and the C-peptide levels were 5.2±0.4, 8.0±1.0, 10.4±1.6, 10.4±1.7 and 10.1±1.0 ng/ml and its response was also greater than that of nonobese moderate diabetic patients. 5) The plasma insulin concentrations in 9 severe diabetic subjects were 8.0±3.8, 12.1±3.5, 16.8±4.6, 19

  13. An accurate determination of human grawth hormone content in different pituitary extracts, using a radioimmunoassay with polyacrylamide gel electrophoresis as a bound-free separation system

    International Nuclear Information System (INIS)

    Bartoline, P.; Assis, L.M. de; Scwarz, I.; Pieroni, R.R.

    1977-01-01

    Human growth hormone was extracted and purified according to the method of Roos et al. A first control of its purification and integrity was performed through molecular weight determination by gel filtration on Sephadex G-100 and on plyacrylamide gel electrophoresis (PAGE). Its biological activity was confirmed by the growth promoted in non-hypophysectomized rats at plateau. The main object, however, was the setting up of an accurate, reproducible method that could furnish the more absolute and comparable value of rafioimmunoassayable HGH content in perfect agreement with the results obtained by other laboratories. This was accomplished through a radioimmunoassay system that uses HGH labelled with 125 I, where the separation of the bound from the free antigen is achieved on polyacrylamide gel electrophoresis, by a modification introduced in the original method of Davis. The resulting values, extremely close to that stated by the KABI-Laboratories (Stockolm), through obtained in quite different conditions of incubation, antibody concentration and with no use of second antibody, represent a confident approach to a comparable measure of this hormone in extract, which can also be applied to plasma determinations [pt

  14. C-peptide increases Na,K-ATPase expression via PKC- and MAP kinase-dependent activation of transcription factor ZEB in human renal tubular cells.

    Directory of Open Access Journals (Sweden)

    Dana Galuska

    Full Text Available Replacement of proinsulin C-peptide in type 1 diabetes ameliorates nerve and kidney dysfunction, conditions which are associated with a decrease in Na,K-ATPase activity. We determined the molecular mechanism by which long term exposure to C-peptide stimulates Na,K-ATPase expression and activity in primary human renal tubular cells (HRTC in control and hyperglycemic conditions.HRTC were cultured from the outer cortex obtained from patients undergoing elective nephrectomy. Ouabain-sensitive rubidium ((86Rb(+ uptake and Na,K-ATPase activity were determined. Abundance of Na,K-ATPase was determined by Western blotting in intact cells or isolated basolateral membranes (BLM. DNA binding activity was determined by electrical mobility shift assay (EMSA. Culturing of HRTCs for 5 days with 1 nM, but not 10 nM of human C-peptide leads to increase in Na,K-ATPase α(1-subunit protein expression, accompanied with increase in (86Rb(+ uptake, both in normal- and hyperglycemic conditions. Na,K-ATPase α(1-subunit expression and Na,K-ATPase activity were reduced in BLM isolated from cells cultured in presence of high glucose. Exposure to1 nM, but not 10 nM of C-peptide increased PKCε phosphorylation as well as phosphorylation and abundance of nuclear ERK1/2 regardless of glucose concentration. Exposure to 1 nM of C-peptide increased DNA binding activity of transcription factor ZEB (AREB6, concomitant with Na,K-ATPase α(1-subunit mRNA expression. Effects of 1 nM C-peptide on Na,K-ATPase α(1-subunit expression and/or ZEB DNA binding activity in HRTC were abolished by incubation with PKC or MEK1/2 inhibitors and ZEB siRNA silencing.Despite activation of ERK1/2 and PKC by hyperglycemia, a distinct pool of PKCs and ERK1/2 is involved in regulation of Na,K-ATPase expression and activity by C-peptide. Most likely C-peptide stimulates sodium pump expression via activation of ZEB, a transcription factor that has not been previously implicated in C-peptide

  15. Solid phase tube radioimmunoassay for digoxin detection

    International Nuclear Information System (INIS)

    Stellner, K.; Glatz, C.; Linke, R.

    1975-01-01

    A solid phase radioimmunoassay with 125 I is described for cardiac patients. The test for the digoxin determination and the poisoning due to cardiac glycosides can be measured very accurately and carried out easily. In addition, the test determination can be automatically performed in connection with other tests. (GSE/LH) [de

  16. Insulin and C peptide response, and antibody levels in hepatitis C related chronic liver disease

    International Nuclear Information System (INIS)

    Abbas, Z.; Tariq, N.; Iqbal, M.; Shah, M.A.

    2002-01-01

    Objective: Patients with cirrhosis due to hepatitis C (HC) have an increased prevalence of diabetes mellitus. The pathogenic mechanism by which HC predisposes to DM is not clear. The objective of this study was to determine the insulin and C-peptide response to 75 gram oral glucose load and measure anti phospholipid antibody levels in patients with chronic liver disease due to HC. Design: a prospective study. Place and duration of study: This study was conducted at the department of medicine, Jinnah postgraduate medical centre over period of three months. Subjects and methods: An analytical case control study was carried out on 37 patients (m-18,f=19); none of these patients had received interferon. They were divided into four groups: (a) HC cirrhosis with DM (n=9 ), (b) HC cirrhosis without DM (n=11), (c) hepatitis B (HB) cirrhosis without DM (n=7), (d) chronic hepatitis C without DM (n=10). Group C and D were taken as controls. Fasting blood samples were taken and repeated after 2 hours of 75 gram oral glucose load (2 h PG). Result: mean ages of group A,B,C and D were (yr +- SD) 51.3 +- 7.6,48.9 +- 2.4, 33.7 +-10.8 and 31.7 +- 8.8 respectively. There was no statistically significant difference in the age, Pugh score and body mass index of HC cirrhotic patients with and without DM. Patients of group A had higher fasting and 2 h PG glucose levels (P=0.003 and 0.000) and higher fasting insulin level (p=0.045). However, increments in insulin and c peptide levels 2 h PG were much less (p=0.048 and 0.003). HB cirrhotics without diabetes (group C behaved just like HC cirrhotic without diabetes (group B). Patients of group D had normal glucose tolerance and insulin and C peptide levels. All four groups had normal anti phospholipid antibody levels. Conclusion: Patients with cirrhosis due to HC nd HB show evidence of glucose intolerance in spite of hyperinsulinaemia probably due to insulin resistance. HC cirrhotics with diabetes have fasting hyperglycemia in spite of

  17. Solid phase radioimmunoassays

    International Nuclear Information System (INIS)

    Wide, L.

    1977-01-01

    Solid phase coupled antibodies were introduced to facilitate the separation of bound and free labelled ligand in the competitive inhibition radioimmunoassay. Originally, the solid matrix used was in the form of small particles and since then a number of different matrices have been used such as very fine powder particles, gels, paper and plastic discs, magnetic particles and the inside surface of plastic tubes. The coupling of antibodies may be that of a covalent chemical binding, a strong physical adsorbtion, or an immunological binding to a solid phase coupled antigen. New principles of radioimmunoassay such as the solid phase sandwich techniques and the immunoradiometric assay were developped from the use of solid phase coupled antigens and antibodies. The solid phase sandwich techniques are reagent excess methods with a very wide applicability. Several of the different variants of solid phase techniques are suitable for automation. Advantages and disadvantages of solid phase radioimmunoassays when compared with those using soluble reagents are discussed. (orig.) [de

  18. Radioimmunoassay for tetrahydrocortisol

    International Nuclear Information System (INIS)

    Mougey, E.H.

    1978-01-01

    A radioimmunoassay for urinary tetrahydrocortisol (THF) is described. Antibodies were produced in rabbits against a THF-monohemisuccinate:bovine serum albumin conjugate. The radioimmunoassay procedure involves enzymic hydrolysis of the urine, extraction with ethyl acetate, radioimmunoassay, and separation of free from bound steroid with Somogyi reagents. The antibody showed some cross-reaction with tetrahydro substance S (36%) which does not occur in urine in appreciable amounts and with tetrahydrocortisone (10%) which does. An analysis of monkey urine extracts before and after tlc purification revealed that the THF antibody was specific enough to permit assay of urines for THF during stress experiments without a purification step. THF values obtained correlated very highly with 17-hydroxycorticosteroid values on the same urines obtained from monkeys during a chair restraint experience (r = 0.97). Also for comparison pruposes these same urines were assayed for free THF, total cortisol, and free cortisol. The free (unconjugated) steroids showed the greatest percentage increase over basal levels

  19. Theoretical and practical application of radioimmunoassays

    International Nuclear Information System (INIS)

    Sokolowski, G.; Wood, W.G.

    1981-01-01

    This book describes experiences made not only in developing and producing commercial reagent kits, but also those made in university research and diagnostic laboratories. The fundamental principles (radioactivity, immunoassay) are explained briefly and tersely. Then the components of the radioimmunoassay are described in detail and illustrated by selected practical examples (production of antibodies, separation of bound and free portions, standards). This chapter is followed by systematic instructions for composing a radioimmunoassay. The actual conditions of the complex problem of quality safety is explained, a field in which particularly the authors are to be regarded as pioneers. Finally an outlook indicates that radioactive alternatives, incorporating the principle of immunologic determinations methods, are available or will be developed for at least a few radioimmunoassays. (orig./MG) [de

  20. Radioimmunoassay of cholylglycine in serum

    International Nuclear Information System (INIS)

    Wakushima, Tadashi; Yamanishi, Yasuhito; Hirayama, Chisato

    1979-01-01

    Serum levels of cholylglycines (CG) were determined by radioimmunoassay and that of total bile acids (TBA) by enzymatic method. In normal subjects, serum levels of CG, TBA and CG/TBA ratio were 0.6 +- 0.4 μM, 7 +- 2 μM, and 0.08 +- 0.06, respectively. They were increased markedly in acute hepatitis and moderately in chronic hepatitis and cirrhosis. Thus, measurement of serum CG as compared with serum TBA appears to be a sensitive liver test. (author)

  1. Radioimmunoassay in children with glomerulonephritis

    International Nuclear Information System (INIS)

    Ametov, A.S.; Gavryushova, L.P.; Shashinka, M.; Mumladze, Eh.B.; Tvorogova, T.M.; Dakhuk, B.; Dronova, V.I.; Toritsina, D.K.; Petrova, T.V.

    1985-01-01

    Proceeding from a radioimmunoassay of various biologically active substances in the blood and urine (ACTH, cortisol, FSH, LH, prolatin, progesterone, estradiol, plasma renin activity and β 2 -microglobulin) of 220 children with glomerulonephritis change of all indices with relation to the type and gravity of glomerulonephritis as well as renal function was revealed. The nature of influence on corticosteroid and immunosuppressive therapy was shown. The authors consider it appropriate to use the determination of biologically active substances in the blood and urine for a more profound estimation of a child's status

  2. Protective effect of C-peptide on experimentally induced diabetic nephropathy and the possible link between C-peptide and nitric oxide.

    Science.gov (United States)

    Elbassuoni, Eman A; Aziz, Neven M; El-Tahawy, Nashwa F

    2018-06-01

    Diabetic nephropathy one of the major microvascular diabetic complications. Besides hyperglycemia, other factors contribute to the development of diabetic complications as the proinsulin connecting peptide, C-peptide. We described the role of C-peptide replacement therapy on experimentally induced diabetic nephropathy, and its potential mechanisms of action by studying the role of nitric oxide (NO) as a mediator of C-peptide effects by in vivo modulating its production by N G -nitro-l-arginine methyl ester (L-NAME). Renal injury markers measured were serum urea, creatinine, tumor necrosis factor alpha, and angiotensin II, and malondialdehyde, total antioxidant, Bcl-2, and NO in renal tissue. In conclusion, diabetic induction resulted in islet degenerations and decreased insulin secretion with its metabolic consequences and subsequent renal complications. C-Peptide deficiencies in diabetes might have contributed to the metabolic and renal error, since C-peptide treatment to the diabetic rats completely corrected these errors. The beneficial effects of C-peptide are partially antagonized by L-NAME coadministration, indicating that NO partially mediates C-peptide effects.

  3. Radioimmunoassay of pancreatic glucagon

    International Nuclear Information System (INIS)

    Nooijen, W.J.

    1979-01-01

    The author presents some of the problems and concepts related to the development of a radioimmunoassay of pancreatic glucagon. A specific derivatization of glucagon for raising specific anti-glucagon antisera is introduced, and special procedures for diminishing the non-specific effect are outlined. (G.T.H.)

  4. Erythropoietin radioimmunoassay studies

    International Nuclear Information System (INIS)

    Garcia, J.F.

    1982-01-01

    A highly sensitive radioimmunoassay capable of measuring erythropoietin concentrations in very small amounts of serum as been developed. After establishing normal human values on a large series of serum samples, serum samples from patients with polycythemia vera and patients with secondary polycythemia were obtained and the erythropoietin concentrations measured

  5. Radioimmunoassay for human myoglobin

    International Nuclear Information System (INIS)

    Kondo, Akira

    1981-01-01

    1 A new radioimmunoassay (RIA) for human myoglobin (Mb) using two antibody technique was developed as a microassay of Mb. This RIA is characterized as follows; 1) Radioiodination of human Mb was successfully done for the first time by chloramine T method, which yielded Iabelled Mb with high specific activities ranging 40 - 60 μCi/μg. 2) Affinity chromatography was used to obtain purified anti-human Mb antibody, which improved the sensitivity of the RIA remarkably, and excluded the effects of serum and urine. 2 The sensitivity of the RIA was 1 ng/ml in sera and 2 ng/ml in urine. The average recovery was 92.7%. Both intra-assay and inter-assay coefficients of variation were below 10%. 3 With this method, Mb purified from skeletal and cardiac muscles was shown to have same immunological nature. 4 Serum concentrations of Mb in normal adults were 13.1 +- 6.1 ng/ml (mean +- S.D.) with a range of 1 - 28 ng/ml. No sex difference was observed. Urinary Mb Ievels in normal adults were less than 4 ng/ml and 24-hour urinary excretions were less than 6 μg. With this method, serum and urinary Mb concentrations were determined in patients with various disorders such as myopathies and myocardial disorders and with anesthesia. Serum Mb concentrations were revealed to be elevated to 50000 ng/ml in malignant hyperthermia, 4000 ng/ml in acute myocardial infarction, 1000 ng/ml in Duchenne muscular dystrophy and 4000 ng/ml in polymyositis. Urinary Mb level was elevated when serum Mb rose to 2000 - 3000 ng/ml. 5 In order to apply RIA of Mb in daily clinical practices, time needed for the assay was shortened by separation of free and antibody-bound Mb by the polyethylene glycol method immediately after incubation was performed at 37 0 C for 2 hours. (author)

  6. Radioimmunoassay for human myoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, A. (Tokushima Univ. (Japan). School of Medicine)

    1981-04-01

    1 A new radioimmunoassay (RIA) for human myoglobin (Mb) using two antibody technique was developed as a microassay of Mb. This RIA is characterized as follows; 1) Radioiodination of human Mb was successfully done for the first time by chloramine T method, which yielded Iabelled Mb with high specific activities ranging 40 - 60 ..mu..Ci/..mu..g. 2) Affinity chromatography was used to obtain purified anti-human Mb antibody, which improved the sensitivity of the RIA remarkably, and excluded the effects of serum and urine. 2 The sensitivity of the RIA was 1 ng/ml in sera and 2 ng/ml in urine. The average recovery was 92.7%. Both intra-assay and inter-assay coefficients of variation were below 10%. 3 With this method, Mb purified from skeletal and cardiac muscles was shown to have same immunological nature. 4 Serum concentrations of Mb in normal adults were 13.1 +- 6.1 ng/ml (mean +- S.D.) with a range of 1 - 28 ng/ml. No sex difference was observed. Urinary Mb Ievels in normal adults were less than 4 ng/ml and 24-hour urinary excretions were less than 6 ..mu..g. With this method, serum and urinary Mb concentrations were determined in patients with various disorders such as myopathies and myocardial disorders and with anesthesia. Serum Mb concentrations were revealed to be elevated to 50000 ng/ml in malignant hyperthermia, 4000 ng/ml in acute myocardial infarction, 1000 ng/ml in Duchenne muscular dystrophy and 4000 ng/ml in polymyositis. Urinary Mb level was elevated when serum Mb rose to 2000 - 3000 ng/ml. 5 In order to apply RIA of Mb in daily clinical practices, time needed for the assay was shortened by separation of free and antibody-bound Mb by the polyethylene glycol method immediately after incubation was performed at 37/sup 0/C for 2 hours.

  7. Radioimmunoassay for pyridostigmine

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, H.G.; Lukey, B.J.; Gepp, R.T.; Corpuz, R.P.; Lieske, C.N.

    1988-01-01

    Pyridostigmine is a cholinergic drug used for the treatment of myasthenia gravis and for antagonizing the effects of non-depolarizing muscle relaxants. In addition, military organizations in several countries have an active interest in pyridostigmine as a pretreatment compound for nerve agent poisoning. Anti-pyridostigmine antibodies were produced in rabbits using a pyridostigmine analog conjugated to keyhole limpet hemocyanin. These antibodies were used for development of a radioimmunoassay that has a linear standard curve (r2=0.986) ranging from 0.5 to 10.0 ng/ml of pyridostigmine bromide in a 0.1-ml plasma sample. This assay measures pyridostigmine in plasma with better sensitivity and much greater through-put than do current state-of-the-art high-performance liquid chromatography techniques. In addition, only small volumes (100ml) of the plasma samples are required. Plasma levels of pyridostigmine were determined in the rat after intramuscular administration (0.056mg/kg) of pyridostigmine bromide. Estimates of the various pharmacokinetic parameters were calculated using the computer program NONLIN84. The results were as follows: apparent volume of distribution = 1.97 1/kg, absorption rate constant = 0.277 min-1, elimination rate constant = 0.0273 min-1, area under the curve = 1010 ng x min/ml, absorption rate half-life = 2.41 min, elimination rate half-life = 24.8 min, maximal plasma concentration (Cmax) = 21.3 ng/ml and time to Cmax = 9.02 min.

  8. Determination of progesterone for reproduction control in cows using a /sup 3/H radioimmunoassay. 1. Methods and choice of testing samples

    Energy Technology Data Exchange (ETDEWEB)

    Taubert, H; Barth, T; Hempel, G; Graeser, K [VEB Saechsisches Serumwerk Dresden (German Democratic Republic); Bezirksinstitut fuer Veterinaerwesen, Dresden (German Democratic Republic))

    1984-01-01

    For verification of cow fertility a /sup 3/H radioimmunoassay of progesterone in milk and blood plasma was developed. It is of high specificity and accuracy as well. Extraction of progesterone from milk was facilitated by application of alcohol. Suggested differences in milk and plasma progesterone levels between pregnant and nonpregnant cows could be revealed.

  9. Prediction of Impending Type 1 Diabetes through Automated Dual-Label Measurement of Proinsulin:C-Peptide Ratio.

    Directory of Open Access Journals (Sweden)

    Annelien Van Dalem

    Full Text Available The hyperglycemic clamp test, the gold standard of beta cell function, predicts impending type 1 diabetes in islet autoantibody-positive individuals, but the latter may benefit from less invasive function tests such as the proinsulin:C-peptide ratio (PI:C. The present study aims to optimize precision of PI:C measurements by automating a dual-label trefoil-type time-resolved fluorescence immunoassay (TT-TRFIA, and to compare its diagnostic performance for predicting type 1 diabetes with that of clamp-derived C-peptide release.Between-day imprecision (n = 20 and split-sample analysis (n = 95 were used to compare TT-TRFIA (AutoDelfia, Perkin-Elmer with separate methods for proinsulin (in-house TRFIA and C-peptide (Elecsys, Roche. High-risk multiple autoantibody-positive first-degree relatives (n = 49; age 5-39 were tested for fasting PI:C, HOMA2-IR and hyperglycemic clamp and followed for 20-57 months (interquartile range.TT-TRFIA values for proinsulin, C-peptide and PI:C correlated significantly (r2 = 0.96-0.99; P<0.001 with results obtained with separate methods. TT-TRFIA achieved better between-day %CV for PI:C at three different levels (4.5-7.1 vs 6.7-9.5 for separate methods. In high-risk relatives fasting PI:C was significantly and inversely correlated (rs = -0.596; P<0.001 with first-phase C-peptide release during clamp (also with second phase release, only available for age 12-39 years; n = 31, but only after normalization for HOMA2-IR. In ROC- and Cox regression analysis, HOMA2-IR-corrected PI:C predicted 2-year progression to diabetes equally well as clamp-derived C-peptide release.The reproducibility of PI:C benefits from the automated simultaneous determination of both hormones. HOMA2-IR-corrected PI:C may serve as a minimally invasive alternative to the more tedious hyperglycemic clamp test.

  10. Commercial radioimmunoassay for beta subunit of human chorionic gonadotropin: falsely positive determinations due to elevated serum luteinizing hormone

    International Nuclear Information System (INIS)

    Fowler, J.E. Jr.; Platoff, G.E.; Kubrock, C.A.; Stuzman, R.E.

    1982-01-01

    Among 17 men who had received seemingly curative treatment for unilateral non-seminomatous germ cell tumors for the testis and who had consistently normal serum human chorionic gonadotropin (HCG) levels at a reference laboratory, 7 (41%) had at least one falsely positive commercial serum HCG determination. To investigate the cause of these falsely positive determinations the authors measured the cross reactivity of luteinizing hormone (LH) and follicle stimulating hormone (FSH) standards in the commercial HCG assay, and studied the relationships between commercial HCG levels and serum LH levels, serum FSH levels and gonadal status in men with and without normal gonadal function. The falsely positive HCG determinations appeared to be due to elevated serum LH levels and cross reactivity of LH in the commercial HCG assay because: 1) there was substantial cross reactivity of the LH standards in the commercial assay, 2) the serum LH was elevated in four of six men with solitary testes, 3) there was a striking correlation between elevated serum LH levels and falsely elevated commercial HCG levels in ten men with solitary or absent testes, and 4) there were no falsely positive HCG determinations in 13 normal men but there were falsely positive HCG determinations in seven of ten anorchid men

  11. Development and standardization of radioimmunoassay technique for human proinsulin determining and its use in the study of type II diabetes mellitus associated to obesity; Desenvolvimento e padronizacao da tecnica de radioimunoensaio para a determinacao de pro-insulina humana e sua aplicacao no estudo do diabetes mellitus tipo II associado a obesidade

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Martha do

    1996-12-31

    The availability of immunoassay methodology for proinsulin is important to define its physiological and pathophysiological significance in humans. Serum concentration of proinsulin are elevated in patients with type II Diabetes Mellitus (NIDDM) and recently diagnosed Type I, so a raised circulating concentration of proinsulin may serve as an early indicator of {beta} cells dysfunction. recently, in NIDDM the serum concentrations of proinsulin and its B-chain-C-peptide junctional split form, des (31-32), were found to correlate with diastolic blood pressure, a risk factor for cardiovascular disease. The development of a sensitive and specific radioimmunoassay (RIA) methodology for proinsulin has been difficult due to its low concentration in serum and the presence of proinsulin conversion intermediates in fluids and tissues. Also other potentially cross-reactive peptides, including insulin and C-peptide, can interfere in the assay. This work describe a highly specific human proinsulin RIA developed by using biosynthetic human proinsulin (hPI) as immunogen, standard and tracer. (author) 133 refs., 17 figs., 36 tabs.

  12. Development and standardization of radioimmunoassay technique for human proinsulin determining and its use in the study of type II diabetes mellitus associated to obesity; Desenvolvimento e padronizacao da tecnica de radioimunoensaio para a determinacao de pro-insulina humana e sua aplicacao no estudo do diabetes mellitus tipo II associado a obesidade

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Martha do

    1997-12-31

    The availability of immunoassay methodology for proinsulin is important to define its physiological and pathophysiological significance in humans. Serum concentration of proinsulin are elevated in patients with type II Diabetes Mellitus (NIDDM) and recently diagnosed Type I, so a raised circulating concentration of proinsulin may serve as an early indicator of {beta} cells dysfunction. recently, in NIDDM the serum concentrations of proinsulin and its B-chain-C-peptide junctional split form, des (31-32), were found to correlate with diastolic blood pressure, a risk factor for cardiovascular disease. The development of a sensitive and specific radioimmunoassay (RIA) methodology for proinsulin has been difficult due to its low concentration in serum and the presence of proinsulin conversion intermediates in fluids and tissues. Also other potentially cross-reactive peptides, including insulin and C-peptide, can interfere in the assay. This work describe a highly specific human proinsulin RIA developed by using biosynthetic human proinsulin (hPI) as immunogen, standard and tracer. (author) 133 refs., 17 figs., 36 tabs.

  13. Use of radioimmunoassay to study secretory potentialities of β-cells in patients with insulin-independent diabetes mellitus

    International Nuclear Information System (INIS)

    Balabolkin, M.I.; Sharapov, A.N.

    1984-01-01

    The nature of insulin and C-peptides secretion in 21 patient with insulin-independent diabetes mellitus (IIDM) with different acetilating phenotype in the course of intravenous glucose loadin is studied by means of the radioimmunoassay. In all patients a different nature of insulin secretion during the first stage is revealed. In the group of fast acetilators an increase in the immuno-reactive insulin (IRI) concentration in the blood serum has been observed, more strongly pronounced in patients with accompanying obesity, whereas in the group of slow acetilators a regular decrease in the IRI level is revealed during this period. The nature of C-peptides secretion in patients with the second type of diabetes mellitus with different acetilator phenotype repeats in the main the IRI dynamics characteristic of fast and slow acetilators. In patients with IIDM with obesity belonging to fast acetilators, the nature of C-peptide secretion has dynamics with differing from IRI

  14. Application of solid-phase radioimmunoassay in determining antibodies to Aujeszky's disease virus in blood serum of vaccinated pigs

    International Nuclear Information System (INIS)

    Rodak, L.; Smid, B.; Valicek, L.

    1983-01-01

    In the blood sera of pigs vaccinated with inactivated vaccines manufactured by three different manufacturers the RIA method was used to determine the specific antibodies to the virus of Aujeszky's disease. In certain groups of vaccinated pigs the results of the RIA examination are unfavourably affected by the bond of antibodies to the cellular antigenous determinants. This proves that following vaccination antibodies are formed not only against the viral antigen but also against the antigens of cells on which the vaccination virus is propagated. These shortcomings are eliminated by the use of suitable cellular cultures for the preparation of viral and control antigens. Antigens are applicable for RIA and for ELISA examinations of blood sera of infected and vaccinated pigs. The advantages are described of the RIA and ELISA methods as compared with the virus neutralization test. (author)

  15. Application of solid-phase radioimmunoassay in determining antibodies to Aujeszky's disease virus in blood serum of vaccinated pigs

    Energy Technology Data Exchange (ETDEWEB)

    Rodak, L; Smid, B; Valicek, L [Vyzkumny Ustav Veterinarniho Lekarstvi, Brno-Medlanky (Czechoslovakia)

    1983-11-01

    In the blood sera of pigs vaccinated with inactivated vaccines manufactured by three different manufacturers the RIA method was used to determine the specific antibodies to the virus of Aujeszky's disease. In certain groups of vaccinated pigs the results of the RIA examination are unfavourably affected by the bond of antibodies to the cellular antigenous determinants. This proves that following vaccination antibodies are formed not only against the viral antigen but also against the antigens of cells on which the vaccination virus is propagated. These shortcomings are eliminated by the use of suitable cellular cultures for the preparation of viral and control antigens. Antigens are applicable for RIA and for ELISA examinations of blood sera of infected and vaccinated pigs. The advantages are described of the RIA and ELISA methods as compared with the virus neutralization test.

  16. Pregnancy-induced rise in serum C-peptide concentrations in women with type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Rehfeld, Jens F; Pedersen-Bjergaard, Ulrik

    2009-01-01

    OBJECTIVE: The purpose of this study was to investigate whether pregnancy induces increased insulin production as a marker of improved beta-cell function in women with long-term type 1 diabetes. RESEARCH DESIGN AND METHODS: This was a prospective study of 90 consecutive pregnant women with type 1.......85). Multivariate regression analysis revealed a positive association between the absolute increase in C-peptide concentrations during pregnancy and decreased A1C from 8 to 33 weeks (P = 0.003). CONCLUSIONS: A pregnancy-induced increase in C-peptide concentrations in women with long-term type 1 diabetes...... in 35 women. RESULTS: C-peptide concentrations gradually increased throughout pregnancy regardless of serum glucose concentrations in the 90 women with a median duration of diabetes of 17 years (range 1-36 years). Among 35 women with paired recordings of stimulated C-peptide, C-peptide production...

  17. Radioimmunoassay in endocpinology

    International Nuclear Information System (INIS)

    Ametov, A.S.; Torjtsina, L.K.

    1983-01-01

    Radioimmunoassay of the level of various hormones in blood for the diagnosis of thyroid gland diseases, diabetes mellitus, pancreatic gland diseases, adrenal cortex, phophorous-calcium exchange, cerebral-hypophysial deseases, peripheric endocrine glands diseases and others are considered. It is shown that CEA methods implantation in clinical practice permits to obtain a number of new data on mechanism of neurohumoral interrelations of various organs and organism systems

  18. Automation systems for radioimmunoassay

    International Nuclear Information System (INIS)

    Yamasaki, Paul

    1974-01-01

    The application of automation systems for radioimmunoassay (RIA) was discussed. Automated systems could be useful in the second step, of the four basic processes in the course of RIA, i.e., preparation of sample for reaction. There were two types of instrumentation, a semi-automatic pipete, and a fully automated pipete station, both providing for fast and accurate dispensing of the reagent or for the diluting of sample with reagent. Illustrations of the instruments were shown. (Mukohata, S.)

  19. Early determination of the congenital hypothyroidism by means of the cuantification of STH and T4 by radioimmunoassay method

    International Nuclear Information System (INIS)

    De Penados, R.C.

    1986-11-01

    It was investigated the advantages and disadvantages and conditions of working for the diagnosis of the congenital hypothyroidism by RIA, and its future implementation. It was determined concentration of neonatal STH and neonatal T4 in whole blood of 517 new borns, obtained by capilar punction and recollected in filter paper. 261 samples were found with levels of T4 between normal limits and STH between 0 and 12.5 u U/ml correspond to a normal thyroid function. 29 samples with normal T4 and STH above 30 u U/ml, correspond to a possible primary hypothyroidism. 171 samples with normal T4 and STH between 12.5 and 30 u U/ml were found. (Author)

  20. Clinical significance of two-step magnetic radioimmunoassay for determining serum free T3 and free T4

    International Nuclear Information System (INIS)

    Chen Bing

    1996-01-01

    The concentrations of the serum free T 3 (FT 3 ), free T 4 (FT 4 ), total triodothyronine (TT 3 ), total thyroxine (TT 4 ) and thyrotropin (TSH) are determined for 355 cases of normal persons, pregnant women and various thyropathetic patients. The normal values of FT 3 and FT 4 are 2.0-8.5 pmol/l, and 9.5-26.5 pmol/l, respectively. Neither FT 3 nor FT 4 is affected by the thyroxine combined with globulin (TBG), which is of unique diagnostic value for those with variable TBG (such as pregnant women hyperthyroidism, hypothyroidism, etc.), FT 3 and FT 4 are the most sensitive indices for diagnosis of hyperthyroidism, and hypothyroidism, respectively. In addition, FT 3 and FT 4 can greatly contribute to the observation of curative effectiveness under treatment

  1. Improved radioimmunoassay of plasma cortisol

    International Nuclear Information System (INIS)

    Donohue, J.; Sgoutas, D.

    1975-01-01

    We report a simplified radioimmunoassay procedure for determination of plasma cortisol. The method offers the advantage that tracer, antibody, and assay buffer are added in a single step with the use of semi-automated equipment. Thus, critical pipetting procedures are minimized, and assay time is reduced to 4 h. No prior extraction or chromatographic purification of cortisol is required. The procedure is simple, reliable, and accurate. For either between-assay or within-assay determinations, the coefficients of variation are about 6 percent. Our results compare well with those obtained from a procedure that included extraction and chromatographic purification of cortisol in several plasma samples. Conditions for optimizing the assay are also discussed. (auth)

  2. Elevation of plasma gonadotropin concentration in response to mammalian gonadotropin releasing hormone (GRH) treatment of the male brown trout as determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Crim, L.W.; Cluett, D.M.

    1974-01-01

    Rapid increase of the plasma gonadotropin concentration as measured by radioimmunoassay has been demonstrated in response to GRH treatment of the sexually mature male brown trout. Peak gonadotropin values were observed within 15 minutes of GRH treatment, however, the return to baseline values was prolonged compared with the mammalian response. These data support the concept that the brain, operating via releasing hormones, plays a role in the control of pituitary hormone secretion in fish

  3. Simultaneous radioimmunoassay for luteinizing hormone and prolactin

    International Nuclear Information System (INIS)

    Steele, M.K.; Deschepper, C.F.

    1985-01-01

    A combined radioimmunoassay (RIA) for the measurement of the anterior pituitary proteins luteinizing hormone (LH) and prolactin (PRL) is described and compared with individual RIAs for these hormones. The standard curves and the sample values for LH and PRL were identical when determined in a combined or in an individual RIA. This technique may prove useful to a number of laboratories where it is desirable to determine levels of more than one hormone in limited sample volumes

  4. Association between low C-peptide and fragility fractures in postmenopausal women without diabetes.

    Science.gov (United States)

    Ferro, Y; Russo, C; Russo, D; Gazzaruso, C; Coppola, A; Gallotti, P; Zambianchi, V; Fodaro, M; Romeo, S; Galliera, E; Marazzi, M G; Romanelli, M M C; Giannini, S; Pujia, A; Montalcini, T

    2017-10-01

    C-peptide has been shown to exert several, previously unknown, biological effects. A recent cross-sectional study demonstrated an association between low C-peptide serum levels and low lumbar bone density of postmenopausal women not affected by diabetes. To date, very little research attention has been directed toward the association between C-peptide and osteoporotic fractures. To contribute toward filling this gap, we investigated the association between C-peptide and fractures in postmenopausal women. A cohort of 133 non-diabetic postmenopausal women with and without a history of fractures was evaluated in this cross-sectional investigation. Standardized interviews were performed to gather information on the patients' fracture history. All of the participants underwent a bone mineral density assessment by DXA, radiographs, and a serum C-peptide measurement. Thirty-four women presented fractures. Bivariate analysis revealed an inverse correlation between C-peptide and fractures (r = -0.27, p = 0.002). A significant difference in mean C-peptide levels was also found between women with vs. without fractures (p = 0.01, adjusted for age, BMI and glucose). Logistic regression analysis showed that C-peptide levels, femoral and vertebral BMD were all negatively associated with fracture status (B = -1.097, ES = 0.401, p = 0.006, 95% CI 0.15-0.73; B = -15.6, SE = 4.17, p C-peptide levels and a history of fractures in postmenopausal women without diabetes. These results suggest that C-peptidemay exert an effect on bone mineral density. However, further large-scale studies are needed to corroborate this finding and investigate the potential underlying mechanisms involved.

  5. Automation of radioimmunoassay

    International Nuclear Information System (INIS)

    Yamaguchi, Chisato; Yamada, Hideo; Iio, Masahiro

    1974-01-01

    Automation systems for measuring Australian antigen by radioimmunoassay under development were discussed. Samples were processed as follows: blood serum being dispensed by automated sampler to the test tube, and then incubated under controlled time and temperature; first counting being omitted; labelled antibody being dispensed to the serum after washing; samples being incubated and then centrifuged; radioactivities in the precipitate being counted by auto-well counter; measurements being tabulated by automated typewriter. Not only well-type counter but also position counter was studied. (Kanao, N.)

  6. Radioimmunoassay of plasma progesterone

    Energy Technology Data Exchange (ETDEWEB)

    Langer, L; Veleminsky, J [Institute of Clinical Endocrinology, Lubochna (Czechoslovakia); Hampl, R; Starka, L [Vyzkumny Ustav Endokrinologicky, Prague (Czechoslovakia); Holan, J [Comenius Univ., School of Medicine, Martin (Czechoslovakia). Dept. of Physics and Nuclear Medicine

    1978-06-30

    A simple modification of plasma progesterone radioimmunoassay is described. 11..cap alpha..-Hydroxyprogesterone hemisuccinate - BSA conjugate was used as an immunogen. (1,2,6,7-H-3) Progesterone specific radioactivity 82 Ci.mmol/sup -1/ was purchased from Radiochemical Centre Amersham (England). The method has been applied for the analysis of more than 2000 plasma samples. The typical fluctuation of progesterone in plasma during the menstrual cycle, using data obtained with this method is illustrated. The reliability criteria of the method are given.

  7. Radioimmunoassay for Melatonin

    International Nuclear Information System (INIS)

    Tapp, E.; Skinner, R.G.; Phillips, V.

    1980-01-01

    A radioimmunoassay for melatonin has been developed and used to measure the level of melatonin of male and post-menopausal female patients coming to operation for benign and malignant conditions. The amount of melatonin in the serum of the females was considerably lower than that in males. No difference could be found between patients suffering from benign and malignant conditions. A patient with a non-parenchymatous pineal tumour had considerably lower levels in the serum at three months after surgery and radiotherapy. A further month later melatonin could not be found in samples of serum taken over a 24-hour period. (author)

  8. Radioimmunoassay to quantitatively measure cell surface immunoglobulins

    International Nuclear Information System (INIS)

    Krishman, E.C.; Jewell, W.R.

    1975-01-01

    A radioimmunoassay techniques developed to quantitatively measure the presence of immunoglobulins on the surface of cells, is described. The amount of immunoglobulins found on different tumor cells varied from 200 to 1140 ng/10 6 cells. Determination of immunoglobulins on the peripheral lymphocytes obtained from different cancer patients varied between 340 to 1040 ng/10 6 cells. Cultured tumor cells, on the other hand, were found to contain negligible quantities of human IgG [pt

  9. Radioimmunoassays - what is their diagnostic value

    International Nuclear Information System (INIS)

    Panitz, N.

    1983-01-01

    A selection is made of hormones and enzymes which are measurable by radioimmunoassay and their organ-specific function is described. Endocrine function tests together with the stimulating or suppressing substances, reaction in the organism and the examined regulation are listed. Non-radioactive immunological determination methods and the use of monoclonal antibodies in vitro and in vivo with ''tumor imaging'' are indicated. (orig.) [de

  10. 21 CFR 862.1135 - C-peptides of proinsulin test system.

    Science.gov (United States)

    2010-04-01

    .... Measurements of C-peptides of proinsulin are used in the diagnosis and treatment of patients with abnormal insulin secretion, including diabetes mellitus. (b) Classification. Class I (general controls). The device...

  11. Quantification of trypsin with a radioimmunoassay in herring larvae (Clupea harengus L.) compared with a highly sensitive fluorescence technique to determine tryptic enzyme activity

    International Nuclear Information System (INIS)

    Ueberschaer, B.; Pedersen, B.H.; Hjelmeland, K.

    1993-01-01

    Enzymatic activity and quantity of the protease trypsin were measured in individual herring larvae (Clupea harengus L.). The enzymatic activity assay was done by a fluorescence technique, and a radioimmunoassay was used for quantification of trypsin. The results are compared and the differences between the techniques discussed. Both methods have similar results, as high or low values in trypsin quantity were reflected in high or low values of tryptic activity. Quantity and activity were linearly and positively correlated, but small differences between methods were found at the lowest detection limits. Both techniques reflect the high variability between individual larvae. (orig.)

  12. Radioimmunoassay of steroid hormone

    International Nuclear Information System (INIS)

    Murakami, Tadashi

    1975-01-01

    Low acid pepsin treated gamma-globulin was applied to ammonium sulfate salting out method, which was a method to separate bound fraction from free one in radioimmunoassay of steroid hormone, and the effect of the separation and the standard curve were examined. Pepsin treated gamma-globulin was prepared in pH 1.5 to 5.5 and then the pepsin was completely removed. It had an effect to accelerate the precipitation in radioimmunoassay of steroid hormone labelled with 3 H. The effect of pepsin treated gamma-globulin to adhere free steroid hormone and to slat out bound one was compared with that of human gamma-globulin. Pepsin treated gamma-globulin, which was water soluble, could easier reach its optimal concentration, and the separation effect was better than human gamma-globulin. The standard curve of it was steeper, particularly in a small dose, and the reproducibility was also better. It could be applied not only to aldosterone and DOC, but also to the steroid hormones, such as progesterone and DHEA, and it seemed suitable for routine measurement method. (Kanao, N.)

  13. Radioimmunoassay of oxytocin

    International Nuclear Information System (INIS)

    Dawood, M.Y.; Raghavan, K.S.; Pociask, C.

    1978-01-01

    The evaluation of a radioimmunoassay of oxytocin is described. The method involved careful collection and transportation of blood at 4 0 C, acidification of the plasma, extraction with Fuller's earth and radioimmunoassay using antisera raised in rabbits immunized against oxytocin conjugated to bovine serum albumin and 125 I-labelled oxytocin. The antisera showed insignificant cross-reaction with a variety of small peptides including vasopressin and vasotocin. The limit of detection of the assay was 2.5 pg with intra-assay and interassay coefficients of variation of 7 to 15% and 12 to 18% respectively. Seventy-seven per cent (88 out of 116) of the pregnant women tested had detect-able maternal plasma oxytocin. Serial samples of maternal plasma showed a significant increase in oxytocin from the first to the second stage of labour and a significant decrease in the third stage. Oxytocin concentrations in the umbilical arterial plasma were significantly higher in patients in labour. The significance of these findings is discussed. (author)

  14. Radioimmunoassay of platelet proteins

    International Nuclear Information System (INIS)

    Pepper, D.S.

    1987-01-01

    The radioimmunoassay of platelet-specific proteins has proven to be an excellent way of monitoring platelet activation in vivo. In contrast to earlier methods such as aggregometry, which has been the major tool used in the evaluation of antiplatelet drugs, the RIAs are capable of working with samples which have been subjected to physiological conditions such as haematocrit, oxygen tension, shear rate and ionized calcium concentration. Also, in contrast to aggregometry, no choice of agonist is necessary. Thus, for the first time it has been possible to monitor the effects of therapeutic intervention with drugs upon the platelet release reaction in vivo. It seems reasonable to equate the release reaction in vivo with activation in vivo, though the stimuli necessarily remain unknown. Nevertheless, the fact that a significant number of the compounds mentioned in Table 3 are indeed capable of reducing platelet activation in vivo and that this effect can be measured objectively is a major step forward in our understanding of platelet pharmacology. Two important goals remain to be achieved, however, the establishment of nonhuman animal models for the evaluation of newer compounds in vivo and longer-term goal of proving in the clinical setting the relevance or otherwise of platelet activation per se to the clinical outcome of a particular disease. In this respect, the availability of accurate, reliable and specific radioimmunoassays has a central role

  15. Fall in C-Peptide During First 2 Years From Diagnosis

    Science.gov (United States)

    Greenbaum, Carla J.; Beam, Craig A.; Boulware, David; Gitelman, Stephen E.; Gottlieb, Peter A.; Herold, Kevan C.; Lachin, John M.; McGee, Paula; Palmer, Jerry P.; Pescovitz, Mark D.; Krause-Steinrauf, Heidi; Skyler, Jay S.; Sosenko, Jay M.

    2012-01-01

    Interpretation of clinical trials to alter the decline in β-cell function after diagnosis of type 1 diabetes depends on a robust understanding of the natural history of disease. Combining data from the Type 1 Diabetes TrialNet studies, we describe the natural history of β-cell function from shortly after diagnosis through 2 years post study randomization, assess the degree of variability between patients, and investigate factors that may be related to C-peptide preservation or loss. We found that 93% of individuals have detectable C-peptide 2 years from diagnosis. In 11% of subjects, there was no significant fall from baseline by 2 years. There was a biphasic decline in C-peptide; the C-peptide slope was −0.0245 pmol/mL/month (95% CI −0.0271 to −0.0215) through the first 12 months and −0.0079 (−0.0113 to −0.0050) from 12 to 24 months (P < 0.001). This pattern of fall in C-peptide over time has implications for understanding trial results in which effects of therapy are most pronounced early and raises the possibility that there are time-dependent differences in pathophysiology. The robust data on the C-peptide obtained under clinical trial conditions should be used in planning and interpretation of clinical trials. PMID:22688329

  16. Pathological consequences of C-peptide deficiency ininsulin-dependent diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Ahmad Ghorbani; Reza Shafiee-Nick

    2015-01-01

    Diabetes is associated with several complicationssuch as retinopathy, nephropathy, neuropathy andcardiovascular diseases. Currently, insulin is the mainused medication for management of insulin-dependentdiabetes mellitus (type-1 diabetes). In this metabolicsyndrome, in addition to decrease of endogenous insulin,the plasma level of connecting peptide (C-peptide) is alsoreduced due to beta cell destruction. Studies in the pastdecade have shown that C-peptide is much more than abyproduct of insulin biosynthesis and possess differentbiological activities. Therefore, it may be possible thatC-peptide deficiency be involved, at least in part, in thedevelopment of different complications of diabetes. It hasbeen shown that a small level of remaining C-peptide isassociated with significant metabolic benefit. The purposeof this review is to describe beneficial effects of C-peptidereplacement on pathological features associated withinsulin-dependent diabetes. Also, experimental andclinical findings on the effects of C-peptide on wholebodyglucose utilization, adipose tissue metabolism andtissues blood flow are summarized and discussed. Thehypoglycemic, antilipolytic and vasodilator effects ofC-peptide suggest that it may contribute to fine-tuningof the tissues metabolism under different physiologic orpathologic conditions. Therefore, C-peptide replacementtogether with the classic insulin therapy may prevent,retard, or ameliorate diabetic complications in patientswith type-1 diabetes.

  17. Radioimmunoassay analysis of baculovirus granulins and polyhedrins

    International Nuclear Information System (INIS)

    Summers, M.D.; Hoops, P.

    1980-01-01

    Granulin and polyhedrin proteins were purified by preparative sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis from the baculoviruses Autographa californica, Rachiplusia ou, Heliothis zea, Heliothis armigera. Trichoplusia ni, and Spodoptera frugiperda. Antisera were raised against Autographa californica (Ac) polyhedrin and Trichoplusia ni (Tn) granulin and analyzed for homologous and heterologous immunoreactivity by immunodiffusion and radioimmunoassay (RIA). Ac polyhedrin and Tn granulin antisera recognized antigenic determinants on several baculovirus polyhedrin and granulin proteins even though the heterologous proteins had different immunoreactivities when compared by competition radioimmunoassay. Antigenic differences among granulin and polyhedrin proteins were also detected by altered slopes of the competition reaction curves. Antiserum raised against Ac polyhedrin which was purified in the presence of SDS was tested by competition RIA for its ability to detect and react with native polyhedrin produced in the infected TN-368 cells. Ac polyhedrin antiserum had similar if not identical ability to bind to native polyhedrin and to polyhedrin purified in the presence of SDS

  18. Anamnesis of the radioimmunoassay: A historical reminiscence

    Energy Technology Data Exchange (ETDEWEB)

    Kallee, E

    1984-01-27

    Anamnesis of the Radioimmunoassay - A Historical Reminiscence: Several requirements have to be met before the first radioimmunoassay of a proteohormone (i.e., insulin) could be developed. One of these requirements was that iodination ought not substantially impair the immunologic properties of the insulin molecule. Since the reversibility of antigen adsorption to antibodies is the most important basis of all immunoassays, the adsorptive behavior of proteins first had to be studied at extremely low protein concentrations. Only after these requirements had been investigated was direct electrophoretic detection of a nonprecipitating anti-hormone antibody possible by desorption of insulin on filter paper. Later, the inaccuracy of the species specificity of insulin-binding antibodies proved to be particularly useful for the determination of insulin in human sera.

  19. Variables associated with persistence of C-Peptide secretion among patients with Type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Ibrahim Abbood Zaboon

    2017-01-01

    Full Text Available Background: C-peptide is a reliable method for estimating the beta-cell residual function. The objective of this study to assess the variables associated with persistence of C-peptide secretion among patients with Type 1 diabetes mellitus (T1DM. Patients and Methods: This was a cross-sectional study conducted from October 2015 to September 2016. This study enrolled patients with T1DM with at least 1 year or more duration. Random C-peptide with concomitant plasma glucose at least 144 mg/dl (8 mmol/l was measured and at this cutoff considered as a stimulated value. Variables that were assessed were age at the time of enrollment, age at the diagnosis of diabetes, gender, family history of diabetes, duration of diabetes, frequency of insulin per day, insulin dose (units/kg/day, type of insulin, devices delivery, body mass index (BMI at enrollment, blood pressure, glucose (plasma, lipid profile, glycated hemoglobin (HbA1c, thyrotropin (TSH, and antibodies to glutamic acid decarboxylase (GAD65, thyroid peroxidase antibodies (anti-TPO, and tissue transglutaminase antibodies-IgA (anti-TTG-IgA. Results: A total 324 patients were included in the study. A higher level of C-peptide has been seen if the disease acquired at the age of 18 years and older with detectable C-peptide observed among 17.7% of those diagnosed at age <18 years versus 31.7% for those aged 18 years or above. The more the duration of diabetes, the more is the loss of C-peptide. On logistic regression analysis, only duration of diabetes <6 years, and insulin dose <1 U/kg/day were statistically significantly associated with the detectable level of C-peptide in this cohort of T1DM. Conclusion: Diagnosis of TIDM at a late age, positive family history of diabetes, those requiring <1 U of insulin per kg per day, and higher fasting glucose was associated with higher and more detectable C-peptide. On multivariable analysis, the only duration of diabetes <6 years and insulin dose <1 U of insulin

  20. Application of radioimmunoassay in food industry

    International Nuclear Information System (INIS)

    Rauch, P.; Fukal, L.; Kas, J.

    1983-01-01

    Radioimmunoassay can be used in evaluating the quality and wholesomeness of food. The method is advantageous for its speed, specificity, high sensitivity, relative ease of performance, and the possibility of performing a great number of parallel determinations using automation and computer evaluation. It can be used in determining macromolecules of proteins and enzymes. The determination of papain in beer is shown by way of example. Other possibilities of the method include: the determination of microbial toxins of the peptide nature, vitamins, hormones, antibiotics, pesticides and their residues, alkaloids, and carcinogenic materials. (M.D.)

  1. Radioimmunoassay of type D oncovirus from continuous J-96 cells

    International Nuclear Information System (INIS)

    Vlasenkova, N.K.; Altshtejn, A.D.; Zhdanov, V.M.; Kitsak, V.Ya.

    1978-01-01

    The radioimmunoassay of the J-96 virus and an extract of J-96 cells in the homologous and heterologous systems aimed at detecting antigenic determinants of p25 of Mason-Pfizer virus and group-specific and interspecies antigenic determinants p30 of Rauscher leukaemia virus demonstrated that (1) J-96 virus contains a major internal protein immunologically identical with p25 protein of Mason-Pfizer virus based on the antigenic determinants detectable by the radioimmunoassay used; and (2) no interspecies antigenic determinants characteristic of the major internal protein of mammalian type C viruses were detectable in the J-96 virus or the J-96 cell extract. (author)

  2. Radioimmunoassay for jasmonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Knoefel, H.D.; Brueckner, C.; Kramell, R.; Sembdner, G.; Schreiber, K. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen)

    1984-01-01

    A radioimmunoassay (RIA) for the natural plant growth regulator jasmonic acid (JA) was developed. The antiserum was raised in rabbits against (+-)-JA linked to bovine serum albumin. As tracer tritium labelled (+-)-JA (spec. act. 7.4 x 10/sup 9/ Bq x mmol/sup -1/) was used. Cross-reactivity studies with compounds structurally related to JA demonstrated the antiserum to be specific for JA, abscisic acid normally present in the same extract does not interfer. The RIA has a detection limit of 2 ng (-)-JA methylester, a measuring range 2-200 ng, and no extensive purification is required prior to estimation. Therefore, in JA analysis the RIA described is superior to GC, HPLC, and bioassay. This new method has been employed for studies on the distribution of JA in different plant organs of the broad bean, Vicia faba L.

  3. Radioimmunoassay of synthetic steroids

    Energy Technology Data Exchange (ETDEWEB)

    Raynaud, J -P; Bucourt, R; Salmon, J

    1975-12-01

    The sensitivity of a radioimmunoassay depends on the intrinsic association constant of the interaction between ligand and antibody. Its specificity depends on the position of the chain which forms the link with the antigen. Thus, an antibody specific of estradiol has been obtained by coupling estradiol to albumin via a chain at position 7. For synthetic steroids the structure of which is sufficiency different from that of natural hormones, the requirements for a sensitive assay method not involving chromatography are simply maximum affinity and positioning of the couple at a site which does not undergo metabolic attack. These criteria were used to develop assays for R 2858 and R 2453 which obviate the need to administer radioactive product in clinical pharmacology. Cross-reaction with structural analogs may be used to assay competitors. Thus, R 2323 antibody, highly specific for endogenous steroids, may be used to assay other trienes such as R 1697 (trenbolone) and R 2010 (norgestrienone).

  4. A radioimmunoassay for chicken avidin

    International Nuclear Information System (INIS)

    Kulomaa, M.S.; Elo, H.A.; Tuohimaa, P.J.

    1978-01-01

    A double-antibody solid-phase radioimmunoassay for chicken avidin is reported. Avidin was labelled with 125 I by the chloramine-T method. The bound and free avidin were separated with a second antibody bound to a solid matrix. In the logit-log scale the standard curve was linear from 1-2 to 100-200ng of avidin/ml. Cross-reaction of ovalbumin was less than 0.015%. Saturation of biotin-binding sites of avidin with an excess of biotin decreased radioimmunoassay values by about 15%. Recovery studies indicated that avidin can be assayed from all chicken tissues studied with radioimmunoassay, whereas the [ 14 C]biotin/bentonite method gave poor recoveries for avidin in the liver and kidney. Radioimmunoassay and the [ 14 C]biotin/bentonite method gave similar concentrations for oviduct avidin. (author)

  5. Clinical indications of prolactin radioimmunoassay

    International Nuclear Information System (INIS)

    Lengyel, A.M.J.; Vieira, J.G.H.; Zanella, M.R.; Zampieri, M.; Chacra, A.R.

    1980-01-01

    Is a review is presented of the main clinical uses of prolactin measurements, including the galactorrhea-amenorrhea syndrome, an experiment employing the prolactin radioimmunoassay is related. (Author) [pt

  6. Analysis of changes of serum leptin, C-peptide levels and peripheral fat tissue leptin receptor expression in obesity

    International Nuclear Information System (INIS)

    Du Tongxin; Sun Junjiang; Wang Shukui; Fu Lei

    2002-01-01

    Objective: To explore the mechanism of obesity and obesity accompanied type two diabetes mellitus by investigating changes of serum leptin, C-peptide (C-P) levels and leptin receptor expression in peripheral adipose tissues. Methods: Peripheral leptin receptor density was measured via radio-ligand binding method, serum leptin and C - P levels were measured via radioimmunoassay in 91 cases (38 in obesity group, 23 in over weight, and 30 in normal controls). Results: With the increase of body mass index (BMI), the peripheral leptin receptor density of the over weight and obese cases decreased and was mash less than that of normal cases (both p<0.01, respectively). There was no statistical differences for Kd value among the three groups, suggesting no associated change between the binding ability of leptin receptor to its ligand. There was a negative correlation between BMI and leptin receptor density (r = -0.70, p < 0.01). The serum leptin and C-P levels in weight excess and obese subjects with type two DM were both increased, but significantly higher in obese group than those in weight excess group (p < 0.01). The increase of C-P was much marked than that of leptin. Serum C-P level was positively correlated with BMI. Conclusion: Changes of serum leptin, C-P levels and peripheral leptin receptor expression in cases with simple obesity and obesity accompanied with type two DM were related closely with BMI. Type 2 DM in obese subjects was related with leptin resistance and insulin resistance

  7. C-Peptide Is Independently Associated with an Increased Risk of Coronary Artery Disease in T2DM Subjects: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Lingshu Wang

    Full Text Available C-peptide has been reported to be a marker of subclinical atherosclerosis in type 2 diabetes mellitus (T2DM patients, whereas its role in coronary artery disease (CAD has not been clarified, especially in diabetics with differing body mass indices (BMIs.This cross-sectional study included 501 patients with T2DM. First, all subjects were divided into the following two groups: CAD and non-CAD. Then, binary logistic regression was used to determine the risk factors for CAD for all patients. To clarify the role of obesity, we re-divided all subjects into two additional groups (obese and non-obese based on BMI. Finally, binary logistic regression was used to determine the risk factors for CAD for each weight group.The patients with CAD showed a higher BMI and fasting C-peptide level in addition to an increased prevalence of traditional risk factors for CAD, such as hypertension, insulin resistance, higher cholesterol, cysteine-C (Cys-C and lower estimated glomerular filtration rate (eGFR. Logistic regression analysis showed that fasting C-peptide (OR=1.513, p=0.005, insulin treatment (OR=1.832, p=0.027 hypertension (OR=1.987, p=0.016 and hyperlipidemia (OR=4.159, p<0.001 significantly increased the risk of clinical CAD in the T2DM patients independent of age, gender, diabetes duration, smoking and alcohol statuses, fasting insulin and glucose, hypoglycemic episodes, UA and eGFR. Additionally, in both of the obese (OR=1.488, p=0.049 and non-obese (OR=1.686, p=0.037 DM groups, C-peptide was associated with an increased risk of CAD after multiple adjustments.C-peptide is associated with an increased CAD risk in T2DM patients, no matter whether they are obese or not.

  8. Radioimmunoassay of measles virus hemagglutinin protein G

    International Nuclear Information System (INIS)

    Lund, G.A.; Salmi, A.A.

    1982-01-01

    Guinea pig and rabbit antisera from animals immunized with purified measles virus hemagglutinin (G) protein were used to establish a solid-phase four-layer radioimmunoassay for quantitative measurement of the G protein. The sensitivity of the assay was 2 ng of purified G protein, and 200 μg of protein from uninfected Vero cells neither decreased the sensitivity nor reacted non-specifically in the assay. Radioimmunoassay standard dose-response curves were established and unknown values interpolated from these using the logit program of a desktop computer. Using this procedure, a measles virus growth curve in infected Vero cells was determined by measurement of G protein production. Under these same conditions, hemagglutination was not sensitive enough to detect early hemagglutinin production. Viral antigens in canine distemper virus, Newcastle disease virus, parainfluenza viruses 1-4, simian virus 5, and respiratory syncytial virus-infected cell lysates did not cross-react in the radioimmunoassay. A small degree of cross-reactivity was detected with mumps viral antigens, both with Vero cell-derived (wild-type strain) and egg-derived (Enders strain) purified virus preparations and with a cell lysate antigen prepared from wild-type mumps virus-infected Vero cells. (Auth.)

  9. Radioimmunoassay of measles virus hemagglutinin protein G

    Energy Technology Data Exchange (ETDEWEB)

    Lund, G A; Salmi, A A [Turku Univ. (Finland)

    1982-08-01

    Guinea pig and rabbit antisera from animals immunized with purified measles virus hemagglutinin (G) protein were used to establish a solid-phase four-layer radioimmunoassay for quantitative measurement of the G protein. The sensitivity of the assay was 2 ng of purified G protein, and 200 ..mu..g of protein from uninfected Vero cells neither decreased the sensitivity nor reacted non-specifically in the assay. Radioimmunoassay standard dose-response curves were established and unknown values interpolated from these using the logit program of a desktop computer. Using this procedure, a measles virus growth curve in infected Vero cells was determined by measurement of G protein production. Under these same conditions, hemagglutination was not sensitive enough to detect early hemagglutinin production. Viral antigens in canine distemper virus, Newcastle disease virus, parainfluenza viruses 1-4, simian virus 5, and respiratory syncytial virus-infected cell lysates did not cross-react in the radioimmunoassay. A small degree of cross-reactivity was detected with mumps viral antigens, both with Vero cell-derived (wild-type strain) and egg-derived (Enders strain) purified virus preparations and with a cell lysate antigen prepared from wild-type mumps virus-infected Vero cells.

  10. Preparation of Double Antibody Radioimmunoassay for Determination of Alpha fetoprotein as a Tumor Marker using BALB/C Mice as Host Animals

    International Nuclear Information System (INIS)

    Abdel-Ghany, I.Y.; EI- Mouhty, N.R.A.; Shafil, H.M.; Mehany, N.L.

    2009-01-01

    The aim of the present work was to prepare liquid phase radioimmunoassay system (RIA) reagents. Development as well as optimization and validation of this RIA system for the measurement of alpha fetoprotein (AFP) in human serum are described. The production of polyclonal antibodies was carried out by immunizing four BALB/C mice subcutaneously. The preparation of 125 I-AFP tracer was performed using chloramine-T oxidation method. The preparation of AFP standards was done by diluting cord sera using assay buffer. The results obtained provide a highly sensitive,precise and accurate RIA system of AFP based on liquid phase separation. In conclusion, this assay could be used for the diagnosis and management of patients with certain malignant diseases and in prenatal diagnosis of neural tube defects

  11. Type-specific IgG and IgA antibodies in old lymphogranuloma venerum determined by solid-phase radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Meurman, O.; Terho, P.; Sonck, C.E.

    1981-01-01

    A solid-phase radioimmunoassay (RIA) using egg-grown purified Chlamydia trachomatis lymphogranuloma venereum (LGV) serotypes L1, L2, and L3 as antigen was used to measure type-specific IgG and IgA antibodies in sera of 36 patients who had contracted LGV infection about 40 years ago. The RIA test gave compatible results with the standard microimmunofluorescence test, and by RIA it was possible to identify the infecting serotype in 30 out of 36 patients studied. In 28 cases this was L2 and in two cases L1. Each patient had IgG antibodies and most of them (80%) IgA antibodies to at least one of the LGV serotypes. The antibody titers were still high 40 years after the acute infection, being higher than in male patients with a recent chlamydial urethritis. Highest antibody titers were detected in LGV patients who had a severe disease with intestinal involvement.

  12. Type-specific IgG and IgA antibodies in old lymphogranuloma venerum determined by solid-phase radioimmunoassay

    International Nuclear Information System (INIS)

    Meurman, O.; Terho, P.; Sonck, C.E.

    1981-01-01

    A solid-phase radioimmunoassay (RIA) using egg-grown purified Chlamydia trachomatis lymphogranuloma venereum (LGV) serotypes L1, L2, and L3 as antigen was used to measure type-specific IgG and IgA antibodies in sera of 36 patients who had contracted LGV infection about 40 years ago. The RIA test gave compatible results with the standard microimmunofluorescence test, and by RIA it was possible to identify the infecting serotype in 30 out of 36 patients studied. In 28 cases this was L2 and in two cases L1. Each patient had IgG antibodies and most of them (80%) IgA antibodies to at least one of the LGV serotypes. The antibody titers were still high 40 years after the acute infection, being higher than in male patients with a recent chlamydial urethritis. Highest antibody titers were detected in LGV patients who had a severe disease with intestinal involvement. (orig.)

  13. Levels of 25(OHD3, IL-2, and C-peptide in Children with Type 1 Diabetes Mellitus (T1DM Receiving Vitamin D3 Supplementation

    Directory of Open Access Journals (Sweden)

    Tjahyo Suryanto

    2018-01-01

    Full Text Available Type 1 Diabetes Mellitus (T1DM has become a health problem in many countries. T1DM is the consequence of autoimmune destruction process of β cells. There was relationship between vitamin D deficiency with T1DM. The destruction process was caused by an imbalance of pro-inflammatory and anti-inflammatory cytokines. One of the pro-inflammatory cytokines is IL-2. C-peptide examination to see the function of beta cells due to destruction of pancreatic beta cell. Administration of vitamin D3 supplementation still cause controversy and give varying results. This randomized clinical trial was conducted to determine the levels of 25(OHD3, IL-2, and C-peptide in people with T1DM who received vitamin D3 supplementation. The subjects were 26 children with T1DM, divided into K1 group (received vitamin D3 supplementation and K2 group (received placebo. The results showed higher levels of 25(OHD3 in the K1 group and statistically found a significant difference (p = 0.00. Higher levels of IL-2 and lower C-peptide were obtained in the K1 group and no statistically significant differences were found (p = 0.76 and p= 0.26. The insignificant relationship and the negative correlation were found between 25(OHD3 and IL-2 (p = 0.71; r = - 0.12, 25(OHD3 and C-peptide (p = 0.59; r = -0.16, also levels of IL-2 and C-peptide (p = 0.13; r = -0.44 in children with type 1 diabetes who received vitamin D3 supplementation. From this study can be concluded that administration vitamin D3 supplementation in patients with T1DM can increase levels 25(OHD3 significantly. This increase has not significantly lowered levels of IL-2 and increased levels of C-peptide. However, there was an absolute decrease in the rate of slower C-peptide in the supplemented group than in the placebo group.

  14. C-peptide prevents SMAD3 binding to alpha promoters to inhibit collagen type IV synthesis.

    Science.gov (United States)

    Li, Yanning; Zhong, Yan; Gong, Wenjian; Gao, Xuehan; Qi, Huanli; Liu, Kun; Qi, Jinsheng

    2018-07-01

    Activation of transforming growth factor β1 (TGFB1)/SMAD3 signaling may lead to additional synthesis of collagen type IV (COL4), which is a major contributor to extracellular matrix (ECM) accumulation in diabetic nephropathy (DN). C-peptide can attenuate fibrosis to have unique beneficial effects in DN. However, whether and how C-peptide affects TGFB1/SMAD3-activated COL4 synthesis is unclear. In this study, pathological changes, expression of COL4 a1-a5 chains ( Col4a1-a5 ), COL4 distribution and protein and TGFB1 and SMAD3 protein were first assessed in a rat model of diabetes. Then, rat mesangial cells were treated with high glucose (HG) and/or C-peptide to investigate the underlying mechanism. Col4a1-a5 expression, COL4 protein and secretion, TGFB1 protein, SMAD3 nuclear translocation and binding of SMAD3 to its cognate sites in the promoters of Col4a1a2 , Col4a3a4 and Col4a5 were measured. It was found that C-peptide attenuated glomerular pathological changes and suppressed renal Col4a1 -a5 mRNA expression, COL4 protein content and TGFB1 protein content. C-peptide had a dose-dependent effect to inhibit Col4a1-a5 mRNA expression, COL4 protein content and secretion, in HG-stimulated mesangial cells. In addition, the HG-induced increase in TGFB1 protein content was significantly reduced by C-peptide. Although not apparently affecting SMAD3 nuclear translocation, C-peptide prevented SMAD3 from binding to its sites in the Col4a1a2 , Col4a3a4 and Col4a5 promoters in HG-stimulated mesangial cells. In conclusion, C-peptide could prevent SMAD3 from binding to its sites in the Col4a1a2 , Col4a3a4 and Col4a5 promoters, to inhibit COL4 generation. These results may provide a mechanism for the alleviation of fibrosis in DN by C-peptide. © 2018 Society for Endocrinology.

  15. Insulin and C-peptide secretion in non-obese patients with polycystic ovarian disease.

    Science.gov (United States)

    Mahabeer, S; Jialal, I; Norman, R J; Naidoo, C; Reddi, K; Joubert, S M

    1989-09-01

    Plasma glucose, immunoreactive insulin (IRI) and C-peptide responses during an oral glucose tolerance test (oGTT) were assessed in 11 non-obese patients with polycystic ovarian disease (PCOD) and 11 reference subjects matched for age, height and weight. Also, 6 patients with PCOD and 6 normal women were subjected to intravenous glucose tolerance testing (ivGTT) On oGTT, all subjects exhibited normal glucose tolerance; however, PCOD patients had significantly higher mean plasma glucose levels at 30, 60, 90 and 120 min and higher mean incremental glucose areas. In addition the patients with polycystic ovaries showed higher mean basal IRI and C-peptide levels, higher mean glucose stimulated IRI and C-peptide levels and higher mean incremental IRI and C-peptide values. The molar ratios of C-peptide/IRI were significantly lower in the PCOD group at all time intervals after glucose stimulation when compared to the normal women. During ivGTT, there were significantly higher mean glucose levels at 5, 40, 50 and 60 min in the PCOD group when compared to the reference group. The IRI response to intravenous glucose in the PCOD women was similar to the reference group. The findings on oGTT suggest that non-obese patients with PCOD have increased pancreatic IRI secretion as well as impaired hepatic extraction of the hormone.

  16. Radioimmunoassay of triiodothyronine in urine

    International Nuclear Information System (INIS)

    Kosowicz, J.; Gembicki, M.; Schneider, E.; Eder, M.

    1977-01-01

    In 21 cases of hypothyroidism, in 39 cases of hyperthyroidism, in 54 healthy subjects, in 23 pregnant women, and in certain internal diseases determinations of triiodothyronine were carried out in urine by radioimmunoassay. Anti-T 3 antibodies were obtained in rabbits and sheep immunized with a complex of bovine albumin with triiodothyronine ester. Labelled triiodothyronine of high specific activity was obtained by iodinating triodothyronine by the chloramine method. Determinations of triiodothyronine were performed in morning urine and the obtained values were calculated for one-hour excretion. In healthy subjects the excretion of T 3 was from 20 to 95 ng/hour, in hyperthyroidism it was significantly raised to from 120 to over 600 ng/hour, while in most cases of hypothyroidism it was decreased. In pregnancy the urinary excretion of T 3 was normal amounting to from 34 to 87 ng/hour, although in most cases the serum T 3 concentration was raised. In cases of anorexia nervosa and in obese starving subjects the excretion of T 3 fell significantly, and similarly low excretion was found in some cases of debilitating diseases and myocardial infarction. (author)

  17. Stability and reproducibility of a single-sample urinary C-peptide/creatinine ratio and its correlation with 24-h urinary C-peptide.

    Science.gov (United States)

    McDonald, Tim J; Knight, Bridget A; Shields, Beverley M; Bowman, Pamela; Salzmann, Maurice B; Hattersley, Andrew T

    2009-11-01

    C-peptide measurement in blood or 24-h urine samples provides useful information regarding endogenous insulin secretion, but problems related to the rapid degradation of C-peptide in blood and difficulty of 24-h urine collection have limited widespread routine clinical use of this test. We assessed the feasibility of measuring urinary C-peptide (UCP) with correction for creatinine concentration in single urine samples. We analyzed UCP using a routine electrochemiluminescence immunoassay in samples from 21 healthy volunteers. We investigated the stability of UCP with different preservatives and storage conditions and compared the reproducibility of urinary C-peptide/creatinine ratio (UCPCR) in first- and second-void fasting urines, then assessed correlations with 24-h collections. UCPCR was unchanged at room temperature for 24 h and at 4 degrees C for 72 h even in the absence of preservative. UCPCR collected in boric acid was stable at room temperature for 72 h. UCPCR remained stable after 7 freeze-thaw cycles but decreased with freezer storage time and dropped to 82%-84% of baseline by 90 days at -20 degrees C. Second-void fasting UCPCRs were lower than first-void (median 0.78 vs 1.31, P = 0.0003) and showed less variation (CV 33% vs 52%), as second-void UCPCRs were not influenced by evening food-related insulin secretion. Second-void fasting UCPCR was highly correlated with 24-h UCP (r = 0.8, P = 0.00006). Second-void fasting UCPCR is a reproducible measure that correlates well with 24-h UCP in normal samples. The 3-day stability of UCPCR at room temperature greatly increases its potential clinical utility.

  18. Determination of antibodies for the core antigen of the hepatitis B virus by means of a direct radioimmunoassay with /sup 32/P-marked core particles. Nachweis von Antikoerpern gegen das Core Antigen des Hepatitis B Virus durch einen direkten Radioimmunoassay mit /sup 32/P markierten Core Partikeln

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, W

    1983-11-04

    After characterization of the protein kinase of the hepatitus B virus and the purification of this enzyme, the enzyme was proved to be a component of the core particle with a high affinity for ATP. Based on this a new procedure for the determination of the diagnostically important antibody for HBcAg (anti HBc) is presented, namely the direct radioimmunoassay by means of the marking of HBcAg with /sup 32/P. This procedure is much more sensitive than the traditional inhibitory test using an enzyme-marked anti-HBc immunoglobulin as a reagent (EIBA). Using this new RIA anti-HBc was shown to be present in the majority of the EIBA anti-HBc positive serums and also in a large number of EIBA anti-HBc negative serums from a population at high risk for the Hepatitis B virus. The significance of reproducible threshold values was also shown. RIA activity was seldom found in healthy blood donors without HBsAg and anti-HBs. On the other hand blood donors with increased serum transaminase values showed a significantly higher frequency of activity. This weak activity only determinable in dRIA, could be attributed to a very limited heaptitis B viral infection or to a cross-reaction. (TRV)

  19. Radioimmunoassay of polypeptide hormones and enzymes

    International Nuclear Information System (INIS)

    Felber, J.P.

    1974-01-01

    General principles of radioimmunoassay are reviewed. Detailed procedures are reviewed for the following hormones: insulin, pituitary hormones, gonadotropins, parathyroid hormone, ACTH, glucagon, gastrin, and peptide hormones. Radioimmunoassay of enzymes is also discussed. (U.S.)

  20. Radioimmunoassay of human urinary kallikrein

    International Nuclear Information System (INIS)

    Goering, W.

    1980-01-01

    Using a human urinary kallikrein, purified by means of Trasylol sepharose, it has been possible to develop a radioimmunoassay of kallikrein capable of detecting the substance down to a concentration of 0.5 ng/ml. The specific activity of the tracer labelled with 125-iodine using the Chloramine-T method was 30-70 nCi/ng of kallikrein. The antiserum titres for the antikallikrein serum were 1:20.000 up to 1:50.000. Human urine, submandibular and parotid salivae as well as pancreatic secretion in this RIA reacted in the same manner as the kallikrein standard solution. The kallikrein content in urine, as determined by the RIA was between 0 and 300 ng/ml, in the saliva between 400 and 2.000 ng/ml, and in the pancreatic juice between 300 and 12.000 ng/ml. Using human serum, only an incomplete immunological cross-reaction could be achieved. In human liquor as well as in animal preparation, no cross-reacting substances could be detected. (orig.) [de

  1. Radioimmunoassay for human ACTH

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, S; Oyama, H; Tenku, A; Horino, M [Kawasaki Medicial School, Kurashiki, Okayama (Japan); Kobayashi, K

    1977-03-01

    A radioimmunoassay method for human adrenocorticotropic hormone (ACTH) is described. The antiserum was produced in a guinea pig by multiple injections of a total of 1 mg of porcine ACTH adsorbed with CM-cellulose and mixed with complete Freund's adjuvant. The antiserum used for this study at a final dilution of 1:500,000 was obtained from a guinea pig after 10 immunizations. A highly purified native ACTH (Li, ..cap alpha.. sub(h)sup(1-39) ACTH) was used as an assay standard and a tracer hormone. Separation of free and bound hormone was achieved by dextran coated charcoal. Extraction of ACTH from plasma samples was performed by Donald's method modified with silicic acid. The antibody appeared to be directed against the C-terminal portion of the hormone molecule and showed no significant reaction with other pituitary hormones (GH, TSH, LH, FSH, Hpr, Oxytocin, Arginine-and Lysine-Vasopressin). Plasma ACTH levels of 5 healthy subjects at nine o'clock averaged 32 +- 8.5 pg/ml (M +- SD). Plasma ACTH concentrations in a case of Sheehan's syndrome and of an untreated adrenogenital syndrome at nine o'clock were less than 20 and 194 pg/ml, respectively. A case of Cushing's syndrome accompanied with bilateral nodular hyperplasia of the adrenal cortex showed diminished diurnal variation and normal levels of plasma ACTH. In contrast, elevated plasma ACTH levels and lack of diurnal rhythm of ACTH secretion were observed in a suspected case of Cushing's disease.

  2. Radioimmunoassay for urinary albumin

    International Nuclear Information System (INIS)

    Woo, J.; Floyd, M.; Cannon, D.C.; Kahan, B.

    1978-01-01

    We describe a rapid, sensitive, and precise radioimmunoassay for urinary albumin (U/sub alb/). Aliquots of diluted urine were incubated at room temperature for 1 h with 125 I-labelled albumin and a rabbit antiserum monospecifid for human albumin. Phase separation was effected by the double-antibody technique. The dose-response curve was linear in the range of 15.6 to 10,000 ng, equivalent to 4 to 3000 mg/liter of urine. The limit of sensitivity was 16 ng of albumin. The coefficient of assay variation was 4.8%, both at 44 mg/liter and at 1304 mg/liter. A displacement curve obtained with a serially diluted urine sample of high albumin concentration was completely superimposable with the curve for which human albumin was used as a standard. In 26 normal individuals the range for U/sub alb/ was 2.2 to 12.6 mg/24 h, and for albumin clearance (C/sub alb/), 1.8 x 10 -5 --19.6 x 10 -5 ml/min. After renal homografts in 25 patients, U/sub alb/ ranged from 16.9 to 9928 mg/24 h, and C/sub alb/ from 2.7 x 10 -4 to 1.7 x 10 -1 ml/min. Both increased U/sub alb/ and C/sub alb/ correlated well with the severity of renal homograft rejection

  3. Radioimmunoassay for a human prostate specific antigen

    International Nuclear Information System (INIS)

    Machida, T.; Miki, M.; Ohishi, Y.; Kido, A.; Morikawa, J.; Ogawa, Y.

    1983-01-01

    As a marker for prostatic cancer, a prostate-specific antigen was purified from human prostatic tissues. Double antibody radioimmunoassay utilizing immune reaction was developed on the basis of the purified prostatic antigen (PA). Measurement results have revealed that PA radioimmunoassay is much better than prostatic acid phosphatase (PAP) radioimmunoassay in the diagnosis of prostatic cancer

  4. Improvements in the automated radioimmunoassay for cAMP or cGMP

    International Nuclear Information System (INIS)

    Brooker, G.

    1988-01-01

    The work others in developing antibodies and the original radioimmunoassay for cyclic nucleotides provides the basis for these sensitive assays. The acetylation radioimmunoassay for cyclic nucleotides has enabled the measurement of cyclic AMP and cyclic GMP in very small biological samples. This is because accurate determinations can be made in samples containing less than 1 fmol of cyclic AMP or cyclic GMP. The Gamma-Flo automated radioimmunoassay system has been adapted to these assays such that cyclic nucleotides can be automatically measured at a rate of about 60 samples/hr. The Gamma-Flo instrument provides high-precision assays and eliminates human intervention in all steps of the radioimmunoassay. The automated assay has been in continuous operation in our laboratory over the last 10 years and this chapter summarizes the methodology and delineates improvements which have occurred over that time frame. Details for the preparation of the radioligands apply also to the manual acetylated radioimmunoassay for cyclic nucleotides

  5. Radioimmunoassay for tumor antigen of human cervical squamous cell carcinoma

    International Nuclear Information System (INIS)

    Kato, H.; Torigoe, T.

    1977-01-01

    A heterologous antiserum for human cervical squamous cell carcinoma was prepared and specificity determined by Ouchterlony immunodiffusion and immunofluorescence studies. With this antiserum, a tumor antigen was purified from human cervical squamous cell carcinoma tissue. The specificities of the antigen and the antiserum were then re-examined by a radioimmunoassay method using 125 I-labeled purified antigen. Although normal cervical tissue extract showed a moderate cross-reactivity in the radioimmunoassay, the circulating antigen activity could not be detected in normal women or in several patients with other carcinomas, whereas 27 of 35 patients with cervical squamous cell carcinoma showed detectable serum antigen activity. All patients with advanced stages of cervical squamous cell carcinoma showed detectable antigen levels. These results indicate that there is a quantitative abnormality, at least, of this tumor antigen in patients with cervical squamous cell carcinoma and that the radioimmunoassay for the antigen is a potentially useful tool in clinical care

  6. Aflatoxin B1 use in radioimmunoassay

    International Nuclear Information System (INIS)

    Liu Yinkun; Zhang Xiaying; Chen Ruiqun; Gu Tianjue

    1987-01-01

    Antibodies against Aflatoxin B 1 (AFB 1 ) were obtained after multiple-site injections of bovine serum albumin-AFB 1 conjugate into rabbits. The greatest specific binding effciency of antibody for AFB 1 is 70∼80%. The sensitivity of radioimmunoassay (RIA) for AFB 1 is between 0.46∼2.3 ng. The retrievel rate of AFB 1 by RIA from intentionally contaminated serum and rice is between 70∼80%. Detailed methods for the preparation of conjugate, immune serum, and methods for antibody titer determination are described

  7. Radioimmunoassay of serum myoglobin in neuromuscular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Askmark, H; Osterman, P O; Roxin, L E; Venge, P [University Hospital, Uppsala (Sweden)

    1981-01-01

    Radioimmunoassay of serum myoglobin was performed in 85 patients with muscular symptoms. Elevated levels were found in 93% of patients with myogenic myopathy, in 54% with myasthenia gravis and in 50% with neurogenic myopathy. All 11 patients with polymyositis had elevated myoglobin concentrations. In six of seven patients with polymyositis, who were followed up with repeated determinations, a clear relationship between myoglobin levels and clinical course was found. In general serum myoglobin seemed to be a more sensitive indicator of muscle disease than creatine kinase.

  8. Radioimmunoassay of serum myoglobin in neuromuscular diseases

    International Nuclear Information System (INIS)

    Askmark, H.; Osterman, P.O.; Roxin, L.-E.; Venge, P.

    1981-01-01

    Radioimmunoassay of serum myoglobin was performed in 85 patients with muscular symptoms. Elevated levels were found in 93% of patients with myogenic myopathy, in 54% with myasthenia gravis and in 50% with neurogenic myopathy. All 11 patients with polymyositis had elevated myoglobin concentrations. In six of seven patients with polymyositis, who were followed up with repeated determinations, a clear relationship between myoglobin levels and clinical course was found. In general serum myoglobin seemed to be a more sensitive indicator of muscle disease than creatine kinase. (author)

  9. Problems in radioimmunoassay of human lutropin with commercially available regents

    International Nuclear Information System (INIS)

    Hammond, J.E.; Phillips, J.C.; Straight, C.B.; Hammond, M.G.

    1980-01-01

    To evaluate five commercially available reagent sets supplied for the radioimmunoassay of lutropin, we determined whether there was parallelism between the curve given by dilutions of the standards supplied by the manufacturers, by dilutions of a serum pool, and by dilutions of a standard preparation from human pituitaries, LER-907. These studies demonstrated significant analytical problems with three of the five sets. We conclude that each user should carefully evaluate all commercially available radioimmunoassays for lutropin (and, by inference, for other peptide hormones) before use

  10. Relation of muscle indices with metabolic parameters and C-peptide in type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Tuzun, S.; Oner, C.; Dabak, M.R.; Kasikci, H.O.; Sargin, M.

    2017-01-01

    Objective: To assess the relation between bioimpedance measurements and metabolic parameters and C-peptide in patient with type 2 diabetes mellitus (DM). Study Design: Cross-sectional study. Place and Duration of Study: Kartal Dr Lutfi Kirdar Training and Research Hospital, Pendik Kaynarca Diabetes Center, Exercise and Metabolism Unit, between January and March 2015. Methodology: Patients with DM, aged less than 65 years, were assessed for bioimpedance analysis, fasting plasma glucose (FPG), HbA1c, C-peptide levels, triglyceride levels, LDL-cholesterol, and HDL-cholesterol levels. Skeletal muscle index, total muscle index, skeletal muscle percentage, and total muscle percentage were used for muscle-related analyses. Mann-Whitney U-test or independent t-test were used to compare differences between two independent groups. Pearson correlation test or Spearman correlation test were used to find out correlation between variables. Results: A total of 359 DM patients were enrolled in the study. Mean age was 51.6+-8.0 years, and 278 (77.7%) of the participants were females. After adjusting age and gender variables, there was no relation between muscle-related measurements and FPG, triglyceride, LDL-cholesterol (p>0.05). However, there was muscle-related indexes (MRI) positively correlation with C-peptide and inversely associated with HDL-cholesterol (p<0.05). Conclusion: Muscle-related indices positively correlated with C-peptide, which showed endogenous insulin reserve. (author)

  11. A linear graph for digoxin radioimmunoassay

    International Nuclear Information System (INIS)

    Smith, S.E.; Richter, A.

    1975-01-01

    The determination of drug or hormone concentrations by radio-immunoassay involves interpolation of values for radioisotope counts within standard curves, a technique which requires some dexterity in curve drawing and which results in some inaccuracy in practice. Most of the procedures designed to overcome these difficulties are complex and time-consuming. In radioimmunoassays involving saturation of the antibody-binding sites a special case exists in that the bound radioactivity is directly proportional to the specific activity of the ligand in the system. Thus a graph of the ratio of radioactivity bound in the absence to that in the presence of added non-radioactive ligand is linear against the concentration of added ligand (Hales,C.N., and Randle, P.J., 1963, Biochem. J., vol. 88, 137). A description is given of a simple and convenient modification of their method, and its application to the routine clinical determination of digoxin using a commercial kit (Lanoxitest β digoxin radioimmunoassay kit, Wellcome Reagents Ltd.). Specially constructed graph paper, which yields linearity with standard solutions, was designed so that it could be used directly without data transmission. The specific activity function appears as the upper arithmetical horizontal scale; corresponding values of the concentration of non-radioactive ligand in the solution added were individually calculated and appear on the lower scale opposite the appropriate values of the upper scale. The linearity of the graphs obtained confirmed that binding of digoxin was approximately constant through the range of clinical concentrations tested (0.5 to 8ng/ml), although binding declined slightly at higher concentrations. (U.K.)

  12. Influence of molecular weight of DNA on the determination of anti-DNA antibodies in systemic lupus erythematosus (SLE) sera by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Geisert, M; Heicke, B; Metzmann, E; Zahn, R K

    1975-04-01

    Using a radioimmunoassay (RIA) based on the Farr technique with radioactively labeled /sup 3/H-DNA for quantitative measurements of anti-DNA antibodies in sera of patients with systemic lupus erythematosus (SLE), the influence of molecular weight of DNA (ranging from 0.1 x 10/sup 6/ to 22.0 x 10/sup 6/ daltons) on binding and precipitation in this system has been investigated. Comparing our results with mathematical models it follows that one antibody molecule is fixed on the average to a statistical DNA segment of 2 x 10/sup 6/ to 4 x 10/sup 6/ daltons. Furthermore binding capacity of the DNA was found to be independent of the molecular weight, as demonstrated in a double label experiment using /sup 14/C and /sup 3/H-labeled DNA of different size. However, the amount of radioactivity precipitated was found to depend on the molecular weight of the labeled DNA following a non-linear function. It was calculated that a minimal ratio of fixed antibody molecules per a certain size of DNA was necessary for precipitation. The mathematical treatment of the observed non-linear precipitation dependence will be discussed using various statistical models. The results indicate that the quantitative measurements of anti-DNA antibodies with the Farr technique e.g., for diagnosis and control of SLE in clinical immunology is highly dependent on the molecular weight of the labeled DNA used in the assay system and reliable results are only obtained with DNA of a sufficiently high molecular weight. (auth)

  13. Radioimmunoassay for hepatitis B core antigen

    International Nuclear Information System (INIS)

    Sagnelli, E.; Pereira, C.; Triolo, G.; Vernace, S.; Paronetto, F.

    1982-01-01

    Serum hepatitis B core antigen (HBcAg) is an important marker of hepatitis B virus replication. We describe an easy, sensitive radioimmunoassay for determination of HBcAg in detergent-treated serum pellets containing Dane particles. Components of a commercial kit for anticore determination are used, and HBcAG is measured by competitive inhibition of binding of 125 I-labeled antibodies to HBcAg with HBcAg-coated beads. We assayed for HBcAG in the sera of 49 patients with hepatitis B surface antigen (HBsAg)-positive chronic hepatitis, 50 patients with HBsAg-negative chronic hepatitis, and 30 healthy volunteers. HBcAg was detected in 41% of patients with HBsAg-positive chronic hepatitis but not in patients with HBsAg-negative chronic hepatitis. Hepatitis Be antigen (an antigen closely associated with the core of Dane particles) determined in the same sera by radioimmunoassay, was not detected in 50% of HBcAg-positive sera

  14. A radioimmunoassay for anti-virus antibodies in farm animals

    International Nuclear Information System (INIS)

    Rodak, L.; Smid, B.; Sedlacek, M.

    1978-01-01

    A radioimmunoassay for determination of antibodies to Aujeszky's disease virus in piq serum is described. The results show a number of advantaqes of this method over the routinely employed virus-neutralization test. The possibility of using the RIA method in diagnosing other viral diseases of farm animals is suggested. (authors)

  15. Radioimmunoassay of follicle stimulating hornone in human plasma

    International Nuclear Information System (INIS)

    Akande, E.O.

    1976-01-01

    A radioimmunoassay method for Follicle Stimulating Hormone (fsh) in human plasma is described. The method proved to be reliable in determining fsh levels in normally menstruating women as well as women in varying clinical states. The patterns and levels of fsh obtained from 16 menstrual cycles in 12 normally menstruating women showed agreement with previous results of Franchimont, Faiman and Ryan, etc

  16. Quality control of radioiodinated gastrin for radioimmunoassay

    International Nuclear Information System (INIS)

    Ginabreda, M.G.P.; Borghi, V.C.; Bettarello, A.

    1988-07-01

    Radioiodinated human gastrin has been prepared at IPEN laboratory for radioimmunoassay use. This work developed the quality control of this tracer analyzing parameters of the labelling reaction, chromatographic purification and radioimmunoassay. The radioiodination yield obtained in five experiments was reproducible and similar when analyzed on 7% polyaraylamide gel eletrophoresis - PAGE - (mean + - SD of 51.70 + - 10.76%) and by1 25 I incorporation checked through thrichloroacetic acid precipitation - TCA - (57-36 + - 9.69%). Similary, after purification the labelled gastrin revaled high and reproducible purity degree when submitted to PAGE (96.57 + - 1.06%) and CA (94.82 + - 4.20%) analysis. The respective specific activities varied from 62 to 307 uCi/ug, being determined by the self-displacement method, which is based on the immunoactivity of the tracer. In this way, the antibody titers required to bind 50% of the tracer ranged from 1:32.000 to 1:180.000. Consequently, the respective doses producing 50% fall in the maximum response of the radioimmunoassays ranged from 155.0 to 24.0 pmol/1, but remained unchanged for each tracer even after three months of its preparations. The tracers presented very low non-specific binding values (1.78 + - 0.79%), stablespecific binding values (46.49 + - 5.65%) and a good between-assay precision, evaluated by an internal quality control sample (25.71 + - 4.30%) with coefficient of variation of 16.74%). The PAGE analysis of the unlabeled gastrin used in the first and last radioiodination revealed an unique and unaltered component, confirming the quality of the tracers. (author) [pt

  17. Recent advances in steroid radioimmunoassay

    International Nuclear Information System (INIS)

    Jeffcoate, S.L.

    1977-01-01

    The advances since 1974 in the techniques of measuring steroid molecules by radioimmunoassay are reviewed in this paper. They are considered under the following headings: preparation and use of antisera; preparation and use of tracers; preparation of biological samples before assay; dispensing of the reagents in the assay; separation of free and bound radioactivity; counting and data processing; quality control and standardization. (orig.) [de

  18. Radioimmunoassay in the diagnosis of arterial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Slavnov, V N; Olejnik, V A; Yakovlev, A A; Yugrinov, O G; Markov, V V [Kievskij Nauchno-Issledovatel' skij Inst. Ehndokrinologii i Obmena Veshchestv (Ukrainian SSR)

    1984-11-01

    The paper is concerned with the results of a study of the aldosterone concentration and renin activity, the general level of catecholamines and their fractions in the peripheral blood and blood taken at selective venography from the vena cava inferior, renal and adrenal veins of 108 patients with hypertension, aldosteroma and idiopathic hyperaldosteronism, adrenal and extraadrenal pheochromocytoma, renovascular and renoparenchymatous arterial hypertension. The aldosterone concentration and renin activity were determined with radioimmunoassay, and the general content of catecholamines and their fractions with a radioenzymatic method using standard kits. It has been shown that the radioimmunoassay to determine the aldosterone concentration and renin activity makes possible differential diagnosis of hypertension, aldosteroma, idiopathic and secondary hyperaldosteronism. A considerable increase in the blood plasma renin activity on the affected side was revealed in the patients with renovascular hypertension, and in renoparenchymatous hypertension it was equal in both renal veins. The study of the total content of catecholamines and their fractions in the blood from different parts of the venous system can be used for topical diagnosis of adrenal and extraadrenal pheochromocytoma.

  19. Radioimmunoassay in the diagnosis of arterial hypertension

    International Nuclear Information System (INIS)

    Slavnov, V.N.; Olejnik, V.A.; Yakovlev, A.A.; Yugrinov, O.G.; Markov, V.V.

    1984-01-01

    The paper is concerned with the results of a study of the aldosterone concentration and renin activity, the general level of catecholamines and their fractions in the peripheral blood and blood taken at selective venography from the vena cava inferior, renal and adrenal veins of 108 patients with hypertension, aldosteroma and idiopathic hyperaldosteronism, adrenal and extraadrenal pheochromocytoma, renovascular and renoparenchymatous arterial hypertension. The aldosterone concentration and renin activity were determined with radioimmunoassay, and the general content of catecholamines and their fractions with a radioenzymatic method using standard kits. It has been shown that the radioimmunoassay to determine the aldosterone concentration and renin activity makes it possible to resort to differential diagnosis of hypertension, aldosteroma, idiopathic and secondary hyperaldosteronism. A considerable increase in the blood plasma renin activity on the affected side was revealed in the patients with renovascular hypertension, and in renoparenchymatous hypertension it was equal in both renal veins. The study of the total content of catecholamines and their fractions in the blood from different parts of the venous system can be used for topical diagnosis of adrenal and extraadrenal pheochromocytoma

  20. Present status and future possibilities of radioimmunoassay in animal production

    International Nuclear Information System (INIS)

    Karg, H.; Claus, R.; Hoffmann, B.; Schallenberger, E.; Schams, D.

    1976-01-01

    Radioimmunoassays and related isotope techniques have provided new possibilities in hormone analysis. Because of the new dimensions of sensitivity (nanogram and picogram range) it became possible to elucidate for many hormones their levels in peripheral blood plasma. Since some steps of the assay procedures could be automatized, and the evaluation computerized, the efficiency (for example, it is possible to run several thousand determinations weekly in one laboratory) can hardly be equalled by non-isotopic hormone analysis techniques. In animal husbandry the technique can be applied to mapping of physiological phenomena, diagnostic approaches in clinics, control of bio-techniques, residue studies of exogenous hormones, and attempts to use hormonal parameters as guide lines in connection with breeding programmes. The discovery that progesterone levels in milk reflect the corpus luteum function introduced far-reaching radioimmunoassay (RIA) application for fertility control under field conditions. With some other hormones, results of single determinations only allow limited interpretation because of different dynamics, for example releasing pattern, short-term (episodic, diurnal) and long-term (seasonal) variations and clearance properties. Furthermore, questions concerning the interactions between the actual plasma level of the hormone determined and the receptor sites in the target organ have to be solved. There are still gaps concerning the development of radioimmunoassays for important hormones. At present and in the foreseeable future of endocrinology in animal production, radioimmunoassays are indispensible. (author)

  1. Elevated C-peptide and insulin predict increased risk of colorectal adenomas in normal mucosa

    International Nuclear Information System (INIS)

    Vidal, Adriana C; Keku, Temitope O; Lund, Pauline Kay; Hoyo, Cathrine; Galanko, Joseph; Burcal, Lauren; Holston, Rachel; Massa, Berri; Omofoye, Oluwaseun; Sandler, Robert S

    2012-01-01

    Lower concentrations of the insulin–like growth factor binding protein-1 (IGFBP-1) and elevated concentrations of insulin or C-peptide have been associated with an increase in colorectal cancer risk (CRC). However few studies have evaluated IGFBP-1 and C-peptide in relation to adenomatous polyps, the only known precursor for CRC. Between November 2001 and December 2002, we examined associations between circulating concentrations of insulin, C-peptide, IGFBP-1 and apoptosis among 190 individuals with one or more adenomatous polyps and 488 with no adenomatous polyps using logistic regression models. Individuals with the highest concentrations of C-peptide were more likely to have adenomas (OR = 2.2, 95% CI 1.4-4.0) than those with the lowest concentrations; associations that appeared to be stronger in men (OR = 4.4, 95% CI 1.7-10.9) than women. Individuals with high insulin concentrations also had a higher risk of adenomas (OR = 3.5, 95% CI 1.7-7.4), whereas higher levels of IGFBP-1 were associated with a reduced risk of adenomas in men only (OR = 0.3, 95% CI 0.1-0.7). Overweight and obese individuals with higher C-peptide levels (>1 st Q) were at increased risk for lower apoptosis index (OR = 2.5, 95% CI 0.9-7.1), an association that remained strong in overweight and obese men (OR = 6.3, 95% CI 1.0-36.7). Higher levels of IGFBP-1 in overweight and obese individuals were associated with a reduced risk of low apoptosis (OR = 0.3, 95% CI 0.1-1.0). Associations between these peptides and the apoptosis index in overweight and obese individuals, suggest that the mechanism by which C-peptide could induce adenomas may include its anti-apoptotic properties. This study suggests that hyperinsulinemia and IGF hormones predict adenoma risk, and that outcomes associated with colorectal carcinogenesis maybe modified by gender

  2. Antibodies to cytoskeletal proteins as evidenced by immunofluorescence microscopy and radioimmunoassay

    International Nuclear Information System (INIS)

    Zugehoer, M.; Struy, H.; Morenz, J.

    1987-01-01

    In patients suffering from chronic hepatitis, collagenosis and infectious mononucleosis, resp., as well as in blood donors antibodies against cytoskeletal antigens such as actin, myosin, actinin, desmin, keratin, and tubulin were determined by radioimmunoassay

  3. Comparison of tritiated and iodinated tracers in the radioimmunoassay of progesterone in cow milk

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R M; Redshaw, M R [Hoechst Pharmaceuticals Research Ltd., Milton Keynes (UK); Holdsworth, R [Milk Marketing Board, Worcester (UK). Veterinary Research Unit

    1980-01-01

    Progesterone levels in the milk of cows were determined by two radioimmunoassay methods. Excellent correlation (r = 0.95) was found between the method using an iodinated radioligand and that using a conventional tritiated tracer.

  4. Diagnosis of prostate cancer using a radioimmunoassay for prostatic acid phosphatase in serum

    International Nuclear Information System (INIS)

    Lea, O.A.; Hoeisaeter, P.Aa.

    1981-01-01

    The paper describes the development and evaluation of a specific radioimmunoassay for the determination of prostatic acid phosphatase in serum as a useful aid in the detection of prostatic cancer. (Auth.)

  5. Antibodies to cytoskeletal proteins as evidenced by immunofluorescence microscopy and radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Zugehoer, M; Struy, H; Morenz, J

    1987-01-01

    In patients suffering from chronic hepatitis, collagenosis and infectious mononucleosis, resp., as well as in blood donors antibodies against cytoskeletal antigens such as actin, myosin, actinin, desmin, keratin, and tubulin were determined by radioimmunoassay.

  6. The effect of oral and intravenous dextrose on C-peptide secretion in ponies.

    Science.gov (United States)

    de Laat, M A; van Haeften, J J; Sillence, M N

    2016-02-01

    Managing equine hyperinsulinemia is crucial for preventing laminitis, but our understanding of the mechanisms involved in insulin dysregulation in this species is incomplete. C-peptide is co-secreted with insulin but is resistant to hepatic metabolism and can be used to study insulin dysregulation. This study examined C-peptide secretion in serial blood samples collected after oral and i.v. dextrose (0.75 g/kg) administration to 9 ponies (BCS, 7.1 ± 0.5). The ponies were designated as hyperinsulinemic (HI) or normoinsulinemic (NI) responders before the study, using oral glucose tests and fasted glucose-to-insulin ratios, and responses were compared between the 2 groups. C-peptide concentrations increased ( dextrose, with similar area under the concentration-time curve (AUC) for both tests and a significant correlation with AUC. The AUC was similar in HI and NI ponies after i.v. dextrose, indicating similar pancreatic capacity for both groups. However, for oral dextrose, the AUC and the AUC were markedly higher ( < 0.05) in the HI ponies, indicating a greater secretion rate of these peptides. Slower insulin clearance might have also contributed to the larger AUC in HI ponies, but this hypothesis requires further investigation with specific measures of hepatic insulin clearance.

  7. Radioimmunoassay determination of the effect on animal reproduction of alternative of feeding suplementation in dairy cows. Alternativas de alimentacion en vacas lecheras y sus efectos en la reproduccion animal, determinados por radioinmunoanalisis, RIA

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, Patricio [Comision Ecuatoriana de Energia Atomica, Quito (Ecuador); Ambuludi, Eduardo [Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del (Ecuador)

    1993-07-01

    The principal object of this trial was to evaluate the influence of three alternatives of feeding suplementation in dairy cows in the post-partum period in ecuadorian highlands. Thirty sic animals in fist lactation were used in this experiment and were divided in three groups according to the feed intake: Group A diet was 5 Kg. of a commercial concentrate mixture with 12 per cent of crude protein plus pasture ad libitum; Group B diet was green banans (Musa paradisiaca) and pasture and Group C diet was the control only pasture. Using Radioimmunoassay technique (RIA), progesterone values were determinated in milk from each cow. the sampling was sequential, two samples a week, starting 6 days after parturition, until the animal was pregnant or until the study was finished, 150 days after post-partum for each cow. This research allowed us to evaluate the ovaric post-partum activity of each group: Frequency and length of the oestrus cycles; efficiency of oestrus detection, calving-first, oestrus period, calving-conception length, conception rate, and services per conception. Additional datas were used in this study such as: milk production, palpations and treatments.

  8. Development of a radioimmunoassay of tetracycline and its derivatives

    International Nuclear Information System (INIS)

    Zitzewitz, A. von.

    1981-01-01

    A radioimmunoassay for tetracycline was developed in the context of the present work. The determination of tetracycline content in biological samples is to be made valid using tetracycline RIA. As well as the carbodiimide method, a by radioimmunologists extremely seldomly used way involving a condensation reaction between protein and haptene via the Mannich reaction was successfully applied. Antibodies were produced using a conventional immunisation method after Abraham, the other applied alternative method after Vaitukaitis et al. The general working methods had to be adapted to the tetracycline RIA. All variable parameters of the antigen-antibody bond were tested to optimize the incubation conditions of the system as well as to control the tracer for a degradation. The detection limit of RIA is 10 - 12 , the measuring range from 10 - 12 to 10 - 10 mol for tetracycline hydrochloride and rolitetracycline respectively and up to 10 - 9 mol for its derivates. The investigations for cross reactions showed a high specificity for tetracycline (100%) and its intravenously appliable pyrrolidino-methyl derivative rolitetracycline (88%). Standard curves could be drawn up using either of the two compounds tetracycline and rolitetracycline as standard. The pharmaco-kinetic behaviour of the parenteral administrable tetracycline was analyzed as example for the possible applications of the tetracycline radioimmunoassay. Parallel animal tests administring 3 H tetracycline hydrochloride were performed for radioimmunoassay reference. The possible application of tetracycline radioimmunoassay in food analysis is discussed. (orig./MG) [de

  9. Development of radioimmunoassay for pantothenic acid in biological tissues

    International Nuclear Information System (INIS)

    Wyse, B.W.

    1977-01-01

    The purpose of this research was to develop a radioimmunoassay for quantitating pantothenic acid levels in biological tissues and to compare the new method with a microbiological procedure. Since pantothenic acid is a nonantigenic compound with a small molecular weight, it was treated as a hapten and conjugated with an immunogenic protein. A new technique for covalently linking haptens with primary alcohol groups to proteins was developed. To prepare an antiserum for the radioimmunoassay, pantothenic acid-bovine serum albumin antigen was injected into the foot pads of rabbits. As antibodies to pantothenic acid hapten were elicited they were characterized using three classical techniques: ring precipitant test, gel diffusion (Ouchterlony), and skin test (Arthus). For the radioimmunoassay an appropriate dilution of antiserum was incubated in the presence of tritium labeled pantothenic acid and non-radioactive pantothenic acid for the standard curve or tissue extracts containing pantothenic acid. After incubation overnight, the antibodies were precipitated and solubilized and the radioactivity was counted in a liquid scintillation counter. Blood pantothenic acid levels of sixty-eight senior citizens were determined by the radioimmunoassay and by microbiological assay with Lactobacillus plantarum. A highly significant correlation was found between the two assays

  10. Purification and characterization of insulin and the C-peptide of proinsulin from Przewalski's horse, zebra, rhino, and tapir (Perissodactyla).

    Science.gov (United States)

    Henry, J S; Lance, V A; Conlon, J M

    1993-02-01

    Within the order Perissodactyla, the primary structure of insulin has been strongly conserved. Insulin from Przewalski's horse and the mountain zebra (suborder Hippomorpha) is the same as that from the domestic horse and differs from insulin from the white rhinoceros and mountain tapir (suborder Ceratomorpha) by a single substitution (Gly-->Ser) at position 9 in the A-chain. A second molecular form of Przewalski's horse insulin isolated in this study was shown to represent the gamma-ethyl ester of the Glu17 residue of the A-chain. This component was probably formed during the extraction of the pancreas with acidified ethanol. The amino acid sequence of the C-peptide of proinsulin has been less well conserved. Zebra C-peptide comprises 31 amino acid residues and differs from Przewalski's horse and domestic horse C-peptide by one substitution (Gln30-->Pro). Rhino C-peptide was isolated only in a truncated form corresponding to residues (1-23) of intact C-peptide. Its amino acid sequence contains three substitutions compared with the corresponding region of horse C-peptide. It is postulated that the substitution (Pro23-->Thr) renders rhino C-peptide more liable to proteolytic cleavage by a chymotrypsin-like enzyme than horse C-peptide. C-peptide could not be identified in the extract of tapir pancreas, suggesting that proteolytic degradation may have been more extensive than in the rhino. In contrast to the ox and pig (order Artiodactyla), there was no evidence for the expression of more than one proinsulin gene in the species of Perissodactyla examined.

  11. Basal C-peptide Level as a Surrogate Marker of Subclinical Atherosclerosis in Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Sung-Tae Kim

    2011-02-01

    Full Text Available BackgroundRecent studies have revealed that C-peptide induces smooth muscle cell proliferation and causes human atherosclerotic lesions in diabetic patients. The present study was designed to examine whether the basal C-peptide levels correlate with cardiovascular risk in type 2 diabetes mellitus (T2DM patients.MethodsData was obtained from 467 patients with T2DM from two institutions who were followed for four years. The medical findings of all patients were reviewed, and patients with creatinine >1.4 mg/dL, any inflammation or infection, hepatitis, or type 1 DM were excluded. The relationships between basal C-peptide and other clinical values were statistically analyzed.ResultsA simple correlation was found between basal C-peptide and components of metabolic syndrome (MS. Statistically basal C-peptide levels were significantly higher than the three different MS criteria used in the present study, the Adult Treatment Panel III (ATP III of the National Cholesterol Education Program's (NCEP's, World Health Organization (WHO, and the International Diabetes Federation (IDF criteria (NCEP-ATP III, P=0.001; IDF, P<0.001; WHO, P=0.029. The multiple regression analysis between intima-media thickness (IMT and clinical values showed that basal C-peptide significantly correlated with IMT (P=0.043, while the analysis between the 10-year coronary heart disease risk by the United Kingdom Prospective Diabetes Study risk engine and clinical values showed that basal C-peptide did not correlate with IMT (P=0.226.ConclusionBasal C-peptide is related to cardiovascular predictors (IMT of T2DM, suggesting that basal C-peptide does provide a further indication of cardiovascular disease.

  12. The promotion of radioimmunoassay in human health

    International Nuclear Information System (INIS)

    Dudley, R.A.

    1983-01-01

    Radioimmunoassay is an analytical technique which makes use of highly specific and sensitive antibodies to segregate particular substances of interest and radioactive tracers to permit quantification of minute amounts. Some procedures use specific biological ''reagents'' other than antibodies and tracers other than radionuclides. Radioimmunoassay plays an enormous role in medical diagnosis and research. Depending on the services to be performed, the radioimmunoassay laboratories are classified into 4 categories. The laboratory of each category is staffed and equipped with facilities according to its scope and quantity of work. From 1980-1982, nearly US$ 2 million had been used under the Agency's Technical Cooperation Programme for the promotion of radioimmunoassay in human health

  13. Promotion of radioimmunoassay in human health

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, R A [International Atomic Energy Agency, Vienna (Austria). Div. of Life Sciences

    1983-06-01

    Radioimmunoassay is an analytical technique which makes use of highly specific and sensitive antibodies to segregate particular substances of interest and radioactive tracers to permit quantification of minute amounts. Some procedures use specific biological ''reagents'' other than antibodies and tracers other than radionuclides. Radioimmunoassay plays an enormous role in medical diagnosis and research. Depending on the services to be performed, the radioimmunoassay laboratories are classified into 4 categories. The laboratory of each category is staffed and equipped with facilities according to its scope and quantity of work. From 1980-1982, nearly US $2 million had been used under the Agency's Technical Cooperation Programme for the promotion of radioimmunoassay in human health.

  14. Radioimmunoassay of luteinizing hormone in hypothyroidism

    International Nuclear Information System (INIS)

    Sobieszczyk, S.

    1975-01-01

    Radioimmunoassay of luteinizing hormone was performed in 18 women with primary hypothyroidism and 15 women with secondary hypothyroidism. The results of determinations were compared with LH values found in healthy women at reproductive age and after menopause. It was observed that in primary hypothyroidism the level of LH is normal, in young women it was from 6 to 25 m IU/ml, while in the postmenopausal period it increased to 70 to 200 m IU/ml. In secondary hypothyroidism due to pituitary hypofunction the LH level is undetectable or lies in the range of lowest values observed in healthy subjects, not exceeding 8 m IU/ml. Determinations of serum LH may be useful for differential diagnosis of primary and secondary hypothyroidism. (author)

  15. Radioimmunoassays for catalase and glutathion peroxidase

    International Nuclear Information System (INIS)

    Baret, A.; Courtiere, A.; Lorry, D.; Puget, K.; Michelson, A.M.

    1982-01-01

    Specific and sensitive radioimmunoassays for human, bovine and rat catalase (CAT) and glutathion Peroxidase (GPX) are described. The obtained values are expressed as enzymatic units per μg of immunoreactive protein. They appear to closely correspond to specific activities of the purified enzymes determined by colorimetric protein-assay. Indeed, the values of the specific activities of purified human CAT is 57.9 k/mg and that of purified rat GPX is 180 units/mg. This result validates the present RIAs and the association of the two techniques allows the determination of a further parameter. In conclusion, RIAs for CAT and GPX can be applied with great specificity and sensitivity to a wide variety of human, rat and bovine medias

  16. Radioimmunoassay of influenza A virus haemagglutinin. I

    International Nuclear Information System (INIS)

    Russ, G.; Styk, B.; Polakova, K.

    1978-01-01

    Haemagglutinin released from influenza A virus recombinant MRC11 [antigenically identical to the strain A/Port Chalmers/1/73 (H3N2)] by bromelain treatment and purified by rate zonal centrifugation (further on B-HA) was examined for possible contamination by neuraminidase. Specific enzymatic activities of the MRC11 virus and the B-HA respectively showed that B-HA contained less than 0.1% of enzymatically active neuraminidase originally present in the virus. Gel double diffusion tests, specificities of rabbit antisera induced by B-HA as well as radioimmunoprecipitation experiments demonstrated that B-HA was devoid of any antigenically active neuraminidase. Precipitation of 125 I-labelled B-HA with antisera to influenza virus recombinants with N2 neuraminidase was evidently caused by antibodies to host antigenic determinant(s) present in these sera. As for purity and radioimmunoprecipitation properties, B-HA is quite suitable for radioimmunoassay experiments. (author)

  17. Radioimmunoassay for detection of VP1 specific neutralizing antibodies of foot and mouse disease virus

    International Nuclear Information System (INIS)

    Patzer, E.J.; Jackson, M.L.; Moore, D.M.

    1985-01-01

    A solid-phase radioimmunoassay was developed for the detection of antibodies against a specific region of the VP1 protein of the A24 and O1 serotypes of foot and mouth disease virus. The antibody titers from the radioimmunoassay showed a positive correlation with neutralizing antibody titers determined by a mouse protection assay. The specificity of the assay resides in the peptide used as antigen. The assay is rapid, reproducible and does not require the use of whole virions. (orig.)

  18. Comparison of acid ethanol extraction and acid gel filtration prior to IGF-I and IGF-II radioimmunoassays; Improvement of determinations in acid ethanol extracts by the use of truncated IGF-I as radioligand

    Energy Technology Data Exchange (ETDEWEB)

    Bang, P; Eriksson, U; Wivall, I -L; Hall, K [Department of Endocrinology, Karolinska Institute, Stockholm (Sweden); Sara, V [Department of Pathology, Karolinska Institute, Stockholm (Sweden)

    1991-01-01

    Insulin-like growth factor binding proteins interfere in the IGF-I and -II radioimmunoassays. In an attempt to overcome this problem, we have compared the use of truncated IGF-I, with reduced IGFBP affinity, and IGF-I as radioligands for IGF-I RIA measurements in serum separated by acid gel filtration or acid ethanol extraction followed by cryo-precipitation. With truncated IGF-I as radioligand the IGF-I measurements in acid gel filtrates and acid ethanol extracts were significantly correlated in healthy subjects (N=42, r=0.91, p<0.001) and in patients with acromegaly (N=10, r=0.85, p<0.01), GH deficiency (N=10, r=0.88, p<0.001) or Type I diabetes mellitus (N=10, r=0.90, p<0.001). In contrast, the IGF-I concentrations in acid ethanol extracts determined with IGF-I as radioligand did not correlate with those in acid gel filtrates using truncated IGF-I radioligand in patients with acromegaly (r=0.61, NS) or GH deficiency (r=0.46, NS). In the latter group the mean IGF-I concentrations measured in acid ethanol extracts were erroneously elevated by 112%. Low-affinity antibodies used for IGF-II RIA determinations failed to give reliable results in acid ethanol extracts from patients with Type I diabetes mellitus or GH deficiency. In conclusion, erroneously high IGF-I concentrations owing to binding of the radioligand to IGFBPs not completely removed by acid ethanol extraction can be avoided by the use of truncated IGF-I as radioligand. (author).

  19. Effect of gestational age and blood glucose on C-peptide excretion rate and clearance in neonates.

    Science.gov (United States)

    Salis, Emma R; Soelbeck, Mikkel K; Reith, David M; Wheeler, Benjamin J; Broadbent, Roland S; Medlicott, Natalie J

    2016-01-01

    The aim of this study was to measure urinary C-peptide concentrations, and then calculate C-peptide clearance (Cl), and excretion rate (UER) in neonates. In addition, the effect of gestational age (GA) and blood glucose levels (BGL) on C-peptide UER were investigated. Insulin concentrations in plasma and C-peptide concentrations were measured in plasma and urine, in 20 neonates. Chemiluminescent immunoassays were used for insulin and C-peptide measurements, with urine diluted to 40% with bovine serum albumin 1% in phosphate buffered saline. Urine volume and time of collection were recorded and used to calculate UER and Cl. The mean Cl of C-peptide was 0.309 ± 0.329 mL/min/kg, and UER was 0.0329 ± 0.0342 pmol/min/kg. Correlations between Cl or UER and GA were not significant (P > 0.05). No significant correlation was shown between Cl or UER and BGL (P > 0.05). Both Cl and UER were highly variable in neonates, but were not correlated with GA. Additionally, BGL did not appear to affect C-peptide UER and Cl. As GA and BGL did not appear to affect Cl and UER, urinary C-peptide may provide a non-invasive method of measuring insulin production in neonates. © 2015 The Authors. Journal of Paediatrics and Child Health © 2015 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  20. C-Peptide Decline in Type 1 Diabetes Has Two Phases: An Initial Exponential Fall and a Subsequent Stable Phase.

    Science.gov (United States)

    Shields, Beverley M; McDonald, Timothy J; Oram, Richard; Hill, Anita; Hudson, Michelle; Leete, Pia; Pearson, Ewan R; Richardson, Sarah J; Morgan, Noel G; Hattersley, Andrew T

    2018-06-07

    The decline in C-peptide in the 5 years after diagnosis of type 1 diabetes has been well studied, but little is known about the longer-term trajectory. We aimed to examine the association between log-transformed C-peptide levels and the duration of diabetes up to 40 years after diagnosis. We assessed the pattern of association between urinary C-peptide/creatinine ratio (UCPCR) and duration of diabetes in cross-sectional data from 1,549 individuals with type 1 diabetes using nonlinear regression approaches. Findings were replicated in longitudinal follow-up data for both UCPCR ( n = 161 individuals, 326 observations) and plasma C-peptide ( n = 93 individuals, 473 observations). We identified two clear phases of C-peptide decline: an initial exponential fall over 7 years (47% decrease/year [95% CI -51%, -43%]) followed by a stable period thereafter (+0.07%/year [-1.3, +1.5]). The two phases had similar durations and slopes in patients above and below the median age at diagnosis (10.8 years), although levels were lower in the younger patients irrespective of duration. Patterns were consistent in both longitudinal UCPCR ( n = 162; ≤7 years duration: -48%/year [-55%, -38%]; >7 years duration -0.1% [-4.1%, +3.9%]) and plasma C-peptide ( n = 93; >7 years duration only: -2.6% [-6.7%, +1.5%]). These data support two clear phases of C-peptide decline: an initial exponential fall over a 7-year period, followed by a prolonged stabilization where C-peptide levels no longer decline. Understanding the pathophysiological and immunological differences between these two phases will give crucial insights into understanding β-cell survival. © 2018 by the American Diabetes Association.

  1. Radioimmunoassay method for detection of gonorrhea antibodies

    International Nuclear Information System (INIS)

    1975-01-01

    A novel radioimmunoassay for the detection of gonorrhea antibodies in serum is described. A radionuclide is bound to gonorrhea antigens produced by a growth culture. In the presence of gonorrhea antibodies in the serum, an antigen-antibody conjugate is formed, the concentration of which can be measured with conventional radiometric methods. The radioimmunoassay is highly specific

  2. Radioimmunoassay for thyroid stimulating hormone (TSH)

    International Nuclear Information System (INIS)

    1980-01-01

    An improved double antibody radioimmunoassay method is described for the determination of thyroid stimulating hormone (TSH) in biological and other fluids. Highly purified second antibody is immobilised on to hydrophilic, hydrolyzed polyacrylamide particles of a suspendable size to form a solid phase second antibody reagent. The immobilised second antibody reagent is used to precipitate the reaction product of the first antibody with labelled and unlabelled thyroid stimulating hormone (TSH-anti-TSH-complex) so as to produce a two-phase system which permits rapid and efficient separation of bound TSH in the solid phase from free TSH in the liquid phase. Details of the preparation of this novel second antibody-polyacrylamide reagent and of the assay procedure for human TSH are described. (U.K.)

  3. Radioimmunoassay for progesterone in bovine milk

    International Nuclear Information System (INIS)

    Ruiz, Miriam; Figueredo, Nancy; Castillo, Sonia; Pizarro

    2002-01-01

    A system for the measurement of progesterone in bovine milk by radioimmunoassay has been developed and validated. This assay includes an iodine tracer purified by HPLC, the standard prepared in fat-free milk and an antibody anti-progesterone combined with second antibody. The detection limit of the assay is at 0.2 nmol/L calculated from the maximum binding menus two standard deviations and the precision is satisfactory. In the recovery assay was used 4 milk different samples and the result was 98% of recuperation. The progesterone was determinate in milk samples from post-partum animals taking samples three times per week for 40 days. The assay is simple, rapid and possibility the progesterone measurement without sample dilution, distinguish the cyclic changes of this hormone that reflect the ovarian activity in the animals. (author)

  4. Role of C-peptide in Altered Lipid Profile among Apparently Healthy Adults of Vijayapura City, Karnataka

    Directory of Open Access Journals (Sweden)

    Chandrahas M.Kulkarni

    2016-04-01

    Full Text Available Background: C-peptide is produced in equimolar concentration during insulin production as inactive molecule by beta islet cells of Langerhans. C-peptide is most useful biomarker of endogenous insulin production. Aim and Objectives: To predict metabolic syndrome in advance by estimation of C-peptide and lipid profile in healthy adults. Material and Methods: Serum C-peptide, fasting blood glucose and lipid profile of 128 healthy individuals were estimated. Adults in the age group of 18 to 60 years of both sexes were included in study. Results: C-peptide levels were increased in 27%, Serum cholesterol in 30%, LDL Cholesterol in 55% and triglyceride levels in 21% of healthy individuals. Significant correlation was observed between C peptide, age, serum cholesterol, LDL and cholesterol LDL ratio in male subjects only. In our study group most of the subjects (both males and females fell in overweight group. Conclusion: Cpeptide level and lipid profile may be considered as useful biomarkers to predict type 2 diabetes mellitus in advance, possibly due to insulin resistance.

  5. The association between newborn regional body composition and cord blood concentrations of C-peptide and insulin-like growth factor I

    DEFF Research Database (Denmark)

    Carlsen, Emma M; Renault, Kristina M; Jensen, Rikke B

    2015-01-01

    BACKGROUND: Third trimester fetal growth is partially regulated by C-peptide and insulin-like growth factor I (IGF-I). Prenatal exposures including maternal obesity and high gestational weight gain as well as high birth weight have been linked to subsequent metabolic disease. We evaluated...... with both C-peptide (p tissue accumulation was associated with cord blood C-peptide and IGF-I. Total and abdominal fat masses were related to C-peptide but not to IGF-I. Thus, newborn adiposity is partially mediated through C-peptide and early...

  6. Radioimmunoassay of thyroid hormones

    International Nuclear Information System (INIS)

    Bartalena, L.; Mariotti, S.; Pinchera, A.

    1987-01-01

    For many years, methods based on iodine content determination have represented the only techniques available for the estimation of total thyroid hormone concentrations in serum. Subsequently, simple, sensitive, and specific radioligand assays for thyroid hormones have replaced these chemical methods. For the purpose of this chapter, iodometric techniques are only briefly summarized for their historical importance, whereas attention is focused on radioligand assays

  7. Radioimmunoassay of protein hormones

    International Nuclear Information System (INIS)

    Talas, M.; Fingerova, H.

    1976-01-01

    A survey is presented of the history of RIA methods for FSH, LH, HCG, HPL and prolactin determinations with special regard to the double antibody method in a kinetic system. Problems are shown in 125 I-labelling protein hormones in preparing own antisera. (L.O.)

  8. A radioimmunoassay for abscisic acid

    International Nuclear Information System (INIS)

    Walton, D.; Dashek, W.; Galson, E.

    1979-01-01

    We have developed a radioimmunoassay (RIA) for abscisic acid (ABA) in the 0.1 ng to 2.5 ng range. Antibodies were obtained from rabbits immunized with ABA bound via its carboxyl group to bovine serum albumin. Cross-reactivity studies indicate that ABA esters are completely cross-reactive with ABA, while trans, trans abscisic acid (t-ABA) phaseic acid (PA) and dihydrophaseic acid (DPA) have much lower but significant cross-reactivities. Purification methods which reduce the levels of cross-reacting substances are described. (orig.) 891 AJ/orig. 892 MKO [de

  9. Radioimmunoassay and other related techniques

    International Nuclear Information System (INIS)

    Zarkawi, Moutaz

    1993-04-01

    The article reviews principles, requirements and reliability criteria of radioimmunoassay (RIA). Since basic reactions involved in RIA and related techniques are derived from reactions which take place in the immune system (IS) of humans and animals, the IS and the way it works will be described. In addition to RIA which involves the use of isotopes as tracers (labels), other non-radioisotopic and recent immunoassay techniques i.e. enzyme-linked immunosorbent assay (ELISA), chemiluminescence immunoassay (CLIA) and fluoroimmunoassay (FIA) will be dealt with. Some important and related terms will be defined and explained. (author). 59 refs., 4 figs

  10. Measurements of urinary kinins by HPLC-radioimmunoassay

    International Nuclear Information System (INIS)

    Fejes-Toth, G.; Naray-Fejes-Toth, A.; Froelich, J.C.

    1984-01-01

    In this paper the authors describe a method for the individual determination of urinary kinins. Extraction from the urine is performed on an Amberlite CG-50 column and kinins are eluted with formic acid. The samples are further purified and kinins are separated by reversed phase HPLC. Bradykinin and lysylbradykinin are quantified by a sensitive radioimmunoassay capable of detecting 0.1 fmol of either peptide. Procedural losses are monitored by measuring the recovery of [ 3 H]bradykinin and [ 3 H]lysylbradykinin. Simple methods for labeling of bradykinin and lysylbradykinin with tritium are also presented. Recoveries of [ 3 H]bradykinin and [ 3 H]lysylbradykinin from biological material ranged between 77 and 91%. The combination of HPLC with radioimmunoassay makes it possible to determine kinin concentrations of biological samples with a higher sensitivity and greater specificity than previous methods. (Auth.)

  11. Development of a radioimmunoassay for pig pancreatic kallikrein

    Energy Technology Data Exchange (ETDEWEB)

    Fink, E; Guettel, C [Muenchen Univ. (Germany, F.R.). Chirurgische Klinik

    1978-07-01

    A radioimmunoassay for the determination of pig pancreatic kallikrein was developed. The chloramine-T method was employed for the labelling of the antigen with /sup 125/I. The assay allows the determination of kallikrein in concentrations as low as 0.4 ..mu..g/l. Pig urinary and pig submandibular kallikreins are indistinguishable from pig pancreatic kallikrein by the assay. No cross reactivity was observed for bovine trypsin and chymotrypsin, porcine trypsin and kallikreins of guinea pig submandibular glands and guinea pig coagulation glands. Because of the high specificity of the assay, which is not attainable with conventional assays based on the enzymatic activity, the radioimmunoassay is highly suited for investigations into the physiological role and the pharmacological mechanism of action of pig glandular kallikreins.

  12. Radioimmunoassay of dehydroepiandrosterone sulfate

    International Nuclear Information System (INIS)

    Vieira, J.G.H.; Furlanetto, R.P.; Russo, E.M.K.; Noguti, K.O.; Chacra, A.R.

    1980-01-01

    The development of a radioimmunological method for the measurement of dehydroepiandrosterone sulfate in serum is described. For the immunization of rabbits, a DHA-3-hemissuccinate-bovine serum albumin conjugate was synthetized and a highly specific anti-serum was produced. The method developed requires only simple dilution prior to assay and the normal values for the different age groups were determined in 146 normal individuals. (Author) [pt

  13. A radioimmunoassay for vasopressin

    International Nuclear Information System (INIS)

    Glaenzer, K.

    1989-01-01

    Described are the development and RIA experimental clinical use of determination for an antidiuretic hormone, 8-arginine vasopressin. The lower limits of detection for this RIA were 0.3 pg/ml in the plasma and 0.6 pg/ml in the urine. For purposes of reference, plasma AVP levels were determined in 50 normal volunteers and found to average 1.2 ± 0.6 pg/ml in females and 1.7 ± 0.7 pg/ml in males. The average AVP excretion with the urine ws 73 ± 43 ng/day. AVP levels determined in urine and plasma samples from patients showing diabetes insipidus centralis or healthy subjects that had not been offered any drink for 24 hours provided evidence in confirmation of supposed physiological interactions. The plasma AVP concentrations of subjects, in which the osmotic processes were impaired by the effects of contrast media used for X-ray examinations, proved to be far above the maximum antidiuretic concentrations and were also very likely to be within the effective range for cardiovascular influences. A series of further examinations was to throw some light on the question whether dramatic surges in ADH during and after surgical replacement of the mitral valve would be accompagnied by the occurrence of a hypoosmolar syndrome. Other examinations were to give insights into the particular role of AVP in the regulation of blood pressure. The last series of examinations had the aim to elucidate the interactions between the angiotensin-renin system and AVP secretion, which were studied in healthy volunteers using the tilting table test both before and during suppression of angiotensin II formation by captopril. There was no conclusive evidence from these examinations that angiotensin II mediates the stimulation of plasma AVP under the conditions of passive orthostatism. (orig./MG) With 24 figs., 8 tabs [de

  14. Radioimmunoassay of trypsin

    International Nuclear Information System (INIS)

    Stagg, B.H.; Wood, T.P.

    1979-01-01

    This review describes the development and application of a novel test to determine levels of human immunoreactive trypsin, an enzyme produced solely by the pancreas, in biological fluids. Being organ-specific, the assay of immunoreactive trypsin should be an ideal marker of pancreatic function, and this is supported by the results of a number of clinical and research investigations. Use of this assay in studies of chronic pancreatitis, juvenile-onset diabetes, and cystic fibrosis, has yielded much valuable data, and it is expected that further research will lead to and improved understanding of these and other conditions associated with the pancreas in health and disease. (author)

  15. Expression and Purification of C-Peptide Containing Insulin Using Pichia pastoris Expression System

    Directory of Open Access Journals (Sweden)

    Mohammed N. Baeshen

    2016-01-01

    Full Text Available Increase in the incidence of Insulin Dependent Diabetes Mellitus (IDDM among people from developed and developing countries has created a large global market for insulin. Moreover, exploration of new methods for insulin delivery including oral or inhalation route which require very high doses would further increase the demand of cost-effective recombinant insulin. Various bacterial and yeast strains have been optimized to overproduce important biopharmaceuticals. One of the approaches we have taken is the production of recombinant human insulin along with C-peptide in yeast Pichia pastoris. We procured a cDNA clone of insulin from Origene Inc., USA. Insulin cDNA was PCR amplified and cloned into yeast vector pPICZ-α. Cloned insulin cDNA was confirmed by restriction analysis and DNA sequencing. pPICZ-α-insulin clone was transformed into Pichia pastoris SuperMan5 strain. Several Zeocin resistant clones were obtained and integration of insulin cDNA in Pichia genome was confirmed by PCR using insulin specific primers. Expression of insulin in Pichia clones was confirmed by ELISA, SDS-PAGE, and Western blot analysis. In vivo efficacy studies in streptozotocin induced diabetic mice confirmed the activity of recombinant insulin. In conclusion, a biologically active human proinsulin along with C-peptide was expressed at high level using Pichia pastoris expression system.

  16. Clinical application of radioimmunoassays

    International Nuclear Information System (INIS)

    Dolecek, R.

    1974-01-01

    The normal average values of immunoreactive insulin (IRI) in the course of the glycemic curve and in glycemia in patients suffering from diabetes, acromegaly and in diagnostics of insulinomas are given. Changes of IRI values after peroral loading with glucose in obese patients and in patients suffering from burns are given. The values of the growth hormone (STH) are given: normal, in patients suffering from obesity, children of small growth, patients with severe burns and in patients suffering from pneumoconiosis with quick progression. The conditions are also stated for the determination of the levels of the luteinizing hormone and the follicle-stimulating hormone, the human placental lactogen and values of renin activity and angiotensin in patients suffering from burns, the values of the adrenocorticotropic hormone and the thyreotropic hormone. (J.P.)

  17. Heterologous radioimmunoassay for arginine vasopressin

    International Nuclear Information System (INIS)

    Shimamoto, K.; Murase, T.; Yamaji, T.

    1976-01-01

    A sensitive and specific radioimmunoassay for arginine vasopressin (AVP) was developed utilizing the antisera against lysine vasopressin (LVP) in combination with a labeled AVP. The assay employs an acetone extraction procedure and detects as little as 0.8 pg. per millimeter of AVP in human plasma. In normal subjects, the mean (+- S.D.) plasma concentration of AVP was 4.9 +- 1.2 pg. per milliliter after fluid deprivation and 1.2 +- 0.4 pg. per milliliter after water loading. Plasma AVP levels correlated significantly with plasma osmolalities. In four patients with diabetes insipidus, plasma AVP concentrations ranged from less than 0.8 to 1.2 pg. per milliliter, whereas six patients with the syndrome of inappropriate ADH secretion showed plasma levels of AVP which correspond to those of the dehydrated state in normal subjects or greater, although plasma osmolalities were low in all cases. It was concluded that the present radioimmunoassay method for AVP provides a useful way of assessing neurohypophyseal function in man

  18. Apparatus for use in radioimmunoassays

    International Nuclear Information System (INIS)

    Chen, C-H.; Tsay, H-M.; Heyer, R.E.

    1979-01-01

    Apparatus for solid-phase antibody separation techniques used in radioimmunoassays is described in this invention. It consists of a rectangular prism tray with multiple wells protruding into its interior from one side. Near the base of the tray is an orifice used for creating evacuated condition within the structure. At the base of each well there is an orifice of such size and shape as to retain an aqueous liquid under given pressure conditions but permit the evacuation of this liquid at reduced pressure. The outlet of these orifices is in the shape of an inverted conical frustrum. Each of the wells contains an antibody coated disc of porous cellulose paper surrounded by a plastic support. The porous nature of the cellulose paper ensures contact between the antibody coating and the antigen. The use of antibody coated porous cellulose paper in combination with the vacuum operated apparatus simplifies the manipulative steps whilst still maintaining the sensitivity of the radioimmunoassay. It also obviates the need for aspiration and thus lessens the risk of contamination from one sample to another. (UK)

  19. Use of radioimmunoassay technique for the determination of post-partum ovaric activity in high and low milk production in dairy cows

    International Nuclear Information System (INIS)

    Villalba, P.; Paneluisa, S.; Arcos, E.

    1993-01-01

    The principal objective of this study was to determinate the post-partum ovarian activity in milking cows of high and low production in one farm of ecuadorian highland. For this experiment was necessary to use 48 animals between second and sith calving, the milk samples were collected according one pre-stablished protocol and the same was: one sample 5th or 6th days, twice a week until the cows were pregnacy and 180 days after parturitium if the cow is open. Additional data were compiled in each farm and both the results of the progesterone by RIA were used to determinate the diferents reproductive parameters in the post-partum of the cows. The most of reproductives parameters in the post-partum of the cows in the both group didn't have significance but the conception rate, services per conception, number of pregnacy cows and percentaje of non visibles heats had one high significance between the treatments

  20. Application of solid-phase radioimmunoassay in determining antibodies to Aujeszky's disease virus in blood serum of vaccinated pigs

    Energy Technology Data Exchange (ETDEWEB)

    Rodak, L.; Smid, B.; Valicek, L. (Vyzkumny Ustav Veterinarniho Lekarstvi, Brno-Medlanky (Czechoslovakia))

    1983-11-01

    In the blood sera of pigs vaccinated with inactivated vaccines manufactured by three different manufacturers the RIA method was used to determine the specific antibodies to the virus of Aujeszky's disease. In certain groups of vaccinated pigs the results of the RIA examination are unfavourably affected by the bond of antibodies to the cellular antigenous determinants. This proves that following vaccination antibodies are formed not only against the viral antigen but also against the antigens of cells on which the vaccination virus is propagated. These shortcomings are eliminated by the use of suitable cellular cultures for the preparation of viral and control antigens. Antigens are applicable for RIA and for ELISA examinations of blood sera of infected and vaccinated pigs. The advantages are described of the RIA and ELISA methods as compared with the virus neutralization test.

  1. The clinical significance of detecting serum glutamic acid decarboxylase antibody (GAD), C-peptide and insulin in diabetics

    International Nuclear Information System (INIS)

    Zheng Tingliang; Zhang Jinchi; Yao Yingfei; Chen Linxing; Huang Hua

    2005-01-01

    Objective: To explore the clinical significance of detecting serum glutamic acid decarboxylase (GAD) antibody, C-peptide (CP) and insulin (INS) in the classification of diabetic patients. Methods: Serum GAD antibody, CP and INS concentration were determined with RIA in 27 patients with type 1 diabetes mellitus (DM1) and 49 patients with type 2 diabetes mellitus (DM2). Sugar-electrode-method was used to detect the concentrations of fasting plasma glucose (FPG) in these patients. Results: The positive rate of GAD antibody in DM1 patients (66.7%) were significantly higher than that in DM2 group (8.2%) (P<0.01), The levels of CP and INS were lower in DM1 group than those in DM2 group as well (P<0.01). Conclusion: GAD antibody is a valuable marker to predict the impairment of β-cell GAD antibody levels, together with CP /FPG and INS/FPG ratios, might be useful in determining the type of DM and guiding the therapy. (authors)

  2. Preserved C-peptide levels in overweight or obese compared with underweight children upon diagnosis of type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Hyeoh Won Yu

    2015-06-01

    Full Text Available PurposeWe hypothesized that overweight or obese children might develop type 1 diabetes mellitus (T1DM early despite residual beta-cell function. Factors independently associated with preservation of C-peptide level were analyzed.MethodsWe retrospectively reviewed the medical data of 135 children aged 2.1-16.5 years with autoimmune T1DM. Body mass index (BMI, pubertal stage, and glycosylated hemoglobin (HbA1c and C-peptide levels were evaluated. Patients were assigned to underweight (22.2%, normal weight (63.7%, and overweight or obese (14.1% groups according to their BMI.ResultsPreservation of serum C-peptide levels (≥0.6 ng/mL was found in 43.0% of subjects. With increasing BMI, the proportions of children with preserved C-peptide levels increased from 33.3% to 41.9% to 63.2%, with marginal significance (P=0.051. Interaction analysis indicated no effect of BMI score on age at onset associated with serum C-peptide levels. The lower the C-peptide level, the younger the age of onset (P<0.001, after adjustment for BMI z-score and HbA1c level. However, no significant relationship between BMI z-score or category and onset age was evident. Upon multivariate-adjusted modeling, the odds that the C-peptide level was preserved increased by 1.2 fold (P=0.001 per year of life, by 3.1 folds (P=0.015 in children presenting without (compared to with ketoacidosis, and by 5.0 folds (P=0.042 in overweight or obese (compared to underweight children.ConclusionOverweight or obese children had slightly more residual beta-cell function than did underweight children. However, we found no evidence that obesity temporally accelerates T1DM presentation.

  3. Fasting serum C-peptide is useful for initial classification of diabetes mellitus in children and adolescents

    Directory of Open Access Journals (Sweden)

    Min Jung Cho

    2014-06-01

    Full Text Available PurposeWith rising obesity rates in children, it is increasingly difficult to differentiate between type 1 and type 2 diabetes mellitus (T1DM, T2DM on clinical grounds alone. Using C-peptide as a method of classifying diabetes mellitus (DM has been suggested. This study aimed to find a correlation between fasting C-peptide level and DM types in children and adolescents.MethodsA total of 223 diabetic children, newly diagnosed at 5 hospitals between January 2001 and December 2012, were enrolled in this study. Initial DM classification was based on clinical and laboratory data including fasting C-peptide at diagnosis; final classification was based on additional data (pancreatic autoantibodies, human leukocyte antigen type, and clinical course.ResultsOf 223 diabetic children, 140 were diagnosed with T1DM (62.8% and the remaining 83 with T2DM (37.2%. The mean serum C-peptide level was significantly lower in children with T1DM (0.80 ng/mL than in children with T2DM (3.91 ng/mL. Among 223 children, 54 had a serum C-peptide level 3.0 ng/mL; 48 of them (97.9% were diagnosed with T2DM.ConclusionIn this study, we found that if the C-peptide level was 3.0 ng/mL, a T1DM diagnosis is unlikely. This finding suggests that serum fasting C-peptide level is useful for classifying DM type at the time of diagnosis in youth.

  4. [Correlation analysis of the pre-pregnant body mass index, the gestational weight gain and umbilical cord blood C peptide].

    Science.gov (United States)

    Chen, X L; Han, Y; Zhao, X M; Liu, Y; Lü, J J

    2017-01-03

    Objective: To explore the correlation among the pre-pregnant body mass index (BMI), gestational weight gain (GWG) and umbilical cord blood C peptide, and to investigate the influence of maternal weight management on the incidence of baby long-term metabolic syndrome. Methods: During May to Aug.2015, 485 pregnant women in Zhejiang Taizhou first people's hospital and Taizhou Huangyan maternal &child care service centre were selected in random and divided into four groups according to pre-pregnant BMI: low body mass, normal body mass, over body mass and obese group, and also divided into two groups for getting gestational diabetes mellitus (GDM) or not. According to the gestational weight gain (GWG), all the cases were divided into two groups: above the Institute Of Medicine (IMO) 2009 recommendations or not. According to the outcome, the GDM group which had received weight control treatment, was divided into successful treat group or not. At last, we tested the umbilical cord blood C peptide and birth weight of each newborn and compared the difference in all subgroups. The correlation between the umbilical cord blood C peptide and birth weight were analysed. Results: (1) In the pre-pregnant BMI groups, there were significant differences of incidence of GDM ( P 0.05). (2) Newborn birth weight and the umbilical cord blood C peptide were positively correlated ( r =0.673, P newborn birth weight in all subgroups. (4) All groups showed correlations with neonatal umbilical cord blood C peptide, the GDM mostly (β=0.58), pre-pregnant BMI secondly (β: 0.36, 0.38) , and GWG weakly (β=0.17). (5) By stratification analysis, in GDM group, low body mass was negatively correlated with umbilical cord blood C peptide ( P gestational weight gain and umbilical cord blood C peptide. Suitable maternal weight control especially pre-pregnant body mass index control will lower the baby long-term metabolic syndrome incidence.

  5. Thyroid hormone radioimmunoassay

    International Nuclear Information System (INIS)

    Rodriguez, S.; Richmond, M.; Quesada, S.; Lahaman, S.; Ramirez, A.; Herrera, J.F.

    1988-01-01

    The International Atomic Energy Agency (AIEA) is carrying out the ARCAL VIII Program 'Thiroid Hormone Readioimmunoassay'. The Immunoassay Laboratory of INCIENSA is in charge of this program, with the participation of four National Hospital System laboratories, which carried out Thyroxine (T4). Triodothyroxine (T3) and Thyroid Stimulating Hormone (TSH) assays with NETRIA Reagents (North East Thames Region Immunoassay Unit). The variability was shown to be between 9-20 per cent for T4, 12-22 per cent for TSH and 22-36 per cent for T3. The study also evaluated the quality of a tracer (T3-l125 and T4 l125) produced at INCIENSA. In this case the intrassay variability was 8,4 per cent for T3 and 6,8 per cent for T4 in 32 determinations evaluated during 6 months. It was concluded that the T4 and TSH tests but not the T3 test are valid and reproducible when NETRIA Ragents are used. The tracer made at INCIENSA can be used up to 6 weeks after the radioiodination with l125. A successful thyroid-related hormones quality control was defined in Costa Rica by taking advantage of the support of a prestigious international agency, the IAEA. (author). 13 refs, 4 figs

  6. Development of SAAP3D force field and the application to replica-exchange Monte Carlo simulation for chignolin and C-peptide.

    Science.gov (United States)

    Iwaoka, Michio; Suzuki, Toshiki; Shoji, Yuya; Dedachi, Kenichi; Shimosato, Taku; Minezaki, Toshiya; Hojo, Hironobu; Onuki, Hiroyuki; Hirota, Hiroshi

    2017-12-01

    Single amino acid potential (SAAP) would be a prominent factor to determine peptide conformations. To prove this hypothesis, we previously developed SAAP force field for molecular simulation of polypeptides. In this study, the force field was renovated to SAAP3D force field by applying more accurate three-dimensional main-chain parameters, instead of the original two-dimensional ones, for the amino acids having a long side-chain. To demonstrate effectiveness of the SAAP3D force field, replica-exchange Monte Carlo (REMC) simulation was performed for two benchmark short peptides, chignolin (H-GYDPETGTWG-OH) and C-peptide (CHO-AETAAAKFLRAHA-NH 2 ). For chignolin, REMC/SAAP3D simulation correctly produced native β-turn structures, whose minimal all-atom root-mean-square deviation value measured from the native NMR structure (except for H) was 1.2 Å, at 300 K in implicit water, along with misfolded β-hairpin structures with unpacked aromatic side chains of Tyr2 and Trp9. Similar results were obtained for chignolin analog [G1Y,G10Y], which folded more tightly to the native β-turn structure than chignolin did. For C-peptide, on the other hand, the α-helix content was larger than the β content on average, suggesting a significant helix-forming propensity. When the imidazole side chain of His12 was protonated (i.e., [His12Hip]), the α content became larger. These observations as well as the representative structures obtained by clustering analysis were in reasonable agreement not only with the structures of C-peptide that were determined in this study by NMR in 30% CD 3 CD in H 2 O at 298 K but also with the experimental and theoretical behaviors having been reported for protonated C-peptide. Thus, accuracy of the SAAP force field was improved by applying three-dimensional main-chain parameters, supporting prominent importance of SAAP for peptide conformations.

  7. Development of SAAP3D force field and the application to replica-exchange Monte Carlo simulation for chignolin and C-peptide

    Science.gov (United States)

    Iwaoka, Michio; Suzuki, Toshiki; Shoji, Yuya; Dedachi, Kenichi; Shimosato, Taku; Minezaki, Toshiya; Hojo, Hironobu; Onuki, Hiroyuki; Hirota, Hiroshi

    2017-12-01

    Single amino acid potential (SAAP) would be a prominent factor to determine peptide conformations. To prove this hypothesis, we previously developed SAAP force field for molecular simulation of polypeptides. In this study, the force field was renovated to SAAP3D force field by applying more accurate three-dimensional main-chain parameters, instead of the original two-dimensional ones, for the amino acids having a long side-chain. To demonstrate effectiveness of the SAAP3D force field, replica-exchange Monte Carlo (REMC) simulation was performed for two benchmark short peptides, chignolin (H-GYDPETGTWG-OH) and C-peptide (CHO-AETAAAKFLRAHA-NH2). For chignolin, REMC/SAAP3D simulation correctly produced native β-turn structures, whose minimal all-atom root-mean-square deviation value measured from the native NMR structure (except for H) was 1.2 Å, at 300 K in implicit water, along with misfolded β-hairpin structures with unpacked aromatic side chains of Tyr2 and Trp9. Similar results were obtained for chignolin analog [G1Y,G10Y], which folded more tightly to the native β-turn structure than chignolin did. For C-peptide, on the other hand, the α-helix content was larger than the β content on average, suggesting a significant helix-forming propensity. When the imidazole side chain of His12 was protonated (i.e., [His12Hip]), the α content became larger. These observations as well as the representative structures obtained by clustering analysis were in reasonable agreement not only with the structures of C-peptide that were determined in this study by NMR in 30% CD3CD in H2O at 298 K but also with the experimental and theoretical behaviors having been reported for protonated C-peptide. Thus, accuracy of the SAAP force field was improved by applying three-dimensional main-chain parameters, supporting prominent importance of SAAP for peptide conformations.

  8. Radioimmunoassay of plasma corticotrophin

    International Nuclear Information System (INIS)

    Hummer, L.

    1977-01-01

    An assay has been established, based on antibodies against the N-terminal part of the ACTH molecule with a high affinity, a detection limit of 2 pg ACTH when assaying 200 ul unextracted plasma, and implying a total incubation time of three days. The antibody has been obtained by immunizing guinea-pigs with synthetic human 1-24 ACTH coupled to bovine serum albumin. The selected antibody has an equilibrium constant of 4 x 10 11 litres/mole in a final dilution of 1/320.000. The antiserum reacts with synthetic human 1-39 ACTH as well as with synthetic human 1-24 ACTH, and the hormonally inactive synthetic human 11-24 ACTH fragment as well as alpha- and beta-melanocyte-stimulating hormones do not cross-react in the assay. The interassay coefficient of variation of replicate estimates was 11-13%. The reproducibility of the standard curve have been evaluated by calculating the amount of ACTH corresponding to 5% of the (B/T)o value, 1.2+-0.4 pg ACTH/tube+-SD and 50% of (B/T)o value, 15.7+-2.6 pg ACTH/tube+-SD. Validation of the assay has been obtained by assaying samples from patients with verified adrenal disorders, and the accuracy is supported by ACTH determinations in test, where metyrapon had been administered intravenously. A stimulation of ACTH production by insulin-induced hypoglycaemia has been found as well. Special attention is always paid as to the conditions for the blood sampling. A reference interval of 10-76 ng/l has been found (115 normal subjects). (orig.) [de

  9. Evaluation of radioimmunoassay of anti-thyroglobulin antibodies

    International Nuclear Information System (INIS)

    Lourme, J.; Dessaint, J.P.; Capron, A.

    1985-01-01

    A statistical analysis is performed on the results of 881 determinations of thyroglobulin antibodies in humans. Antibodies were assayed comparatively by radioimmunoassay using a sandwich method and by tanned red cell haemagglutination. A very good concordance was found between the two techniques, apart from the low titer zone. A significant correlation was observed between on the one side, the radioactivity index of the diluted serum, defined as the increment of radioactivity bound by undiluted patient serum over the positive threshold, divided by this threshold, and, on the other side, the antibody titer, i.e. the reciprocal of the highest serum dilution superior to the positive threshold by radioimmunoassay. The corresponding linear regression allows to define a arbitrary unit system which associates values of the radioactivity index with an average antibody titer [fr

  10. The subcellular and organ distribution and natural form of histidyl-proline diketopiperazine in rat brain determined by a specific radioimmunoassay.

    Science.gov (United States)

    Yanagisawa, T; Prasad, C; Peterkofsky, A

    1980-11-10

    Histidyl-proline diketopiperazine is produced in brain as a product of the metabolism of thyrotropin-releasing hormone. A number of the previously observed central nervous system and pituitary activities resulting from an exposure to thyrotropin-releasing hormone appear to involve the conversion of the releasing factor to the cyclic dipeptide. In the present study, the development of a rabbit antiserum that is highly specific for histidyl-proline diketopiperazine is described; the antiserum has essentially no capability to bind thyrotropin-releasing hormone or a number of other related peptides. The antibody can also distinguish between the natural form of the cyclic dipeptide and a diastereomer containing D-proline. A procedure for extraction, with high yield, of histidyl-proline diketopiperazine from brain is described. With the aid of the specific antiserum it was found that the preponderance of the cyclic dipeptide in rat brain is bound to high molecular weight material, mainly in the range of Mr = 70,000; histidyl-proline diketopiperazine can be disassociated from this material by boiling in salt/methanol solution. The concentration of the dipeptide in rat brain is in the range of 275 to 565 pmol/brain, approximately 2.5 times the concentrations determined for thyrotropin-releasing hormone (113 to 210 pmol/brain). A study of the subcellular distribution of histidyl-proline diketopiperazine and thyrotropin-releasing hormone suggests that the releasing factor is concentrated in synaptosomal vesicles while the diketopiperazine is not. A determination of the regional distribution of thyrotropin-releasing hormone and histidyl-proline diketopiperazine indicated that both peptides are found in highest concentrations in pituitary and hypothalamus, but are detectable in other areas of brain as well.

  11. Diurnal Variations in Serum Glucose, Insulin and C-Peptide of Normal Korean Adults

    International Nuclear Information System (INIS)

    Choi, Du Hyok; Chung, June Key; Lee, Hong Kyu; Koh, Chang Soon; Hong, Kee Suk

    1983-01-01

    It is already well known that many factors are involved in maintaining normal blood glucose level. The amount and components of meal are also thought to be some of the factors which affect the blood glucose and insulin levels. It is reported that as for Koreans sugar takes up over 75% out of 2,098 kcal, the average daily calorie intake per adult. It implies that Koreans take a high-sugar diet compared with Westerners who take 40-50% of sugar out of their total average daily calorie. For the purpose of studying diurnal variations in serum glucose, insulin and C-peptide of normal Koreans adults based on ordinary Korean diet, we selected 13 normal Korean male adults and divided them into two groups, Group I (7 persons) and Group II (6 persons). We put Group I on 3,100 kcal and 75% sugar diet, and Group II on 2,100 kcal and 69% sugar diet per day for over 4 days. Serum glucose, insulin and C-peptide were checked every 30 minutes or every hour throughout 2 hour. Results are as follows: 1. As for serum glucose level, in the preprandial fasting state in the morning, mean±S.D. of Group I was 91.1±3.2 mg%, while that of Group II is 82.5±4.4 mg%. Both groups showed peaks of increased glucose level t postprandial 1 hour after each meal. The peak returned to the level shown during the fasting state at postprandial 1 hour after breakfast while the relatively high glucose levels were maintained respectively even for 2 or 3 hours after lunch and dinner. 2. As for serum insults level, Group I showed mean±S.D. of 14.7±3.0 μU/ml while Group II shows that of 7.0±2.6 μU/ml in the fasting state. Group I particularly showed the largest peak from preprandial a half or one and half an hour to postprandial one hour of lunch, and made relatively small peaks (47.7±10.8 μU/ml) at postprandial 1 hour after breakfast and dinner. No such large peak was marked in Group II, though it showed relatively similar patterns of peak after each meal. 3. As for C-peptide, in the fasting state

  12. Diurnal Variations in Serum Glucose, Insulin and C-Peptide of Normal Korean Adults

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Du Hyok; Chung, June Key; Lee, Hong Kyu; Koh, Chang Soon [Seoul National University College of Medicine, Seoul (Korea, Republic of); Hong, Kee Suk [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1983-03-15

    It is already well known that many factors are involved in maintaining normal blood glucose level. The amount and components of meal are also thought to be some of the factors which affect the blood glucose and insulin levels. It is reported that as for Koreans sugar takes up over 75% out of 2,098 kcal, the average daily calorie intake per adult. It implies that Koreans take a high-sugar diet compared with Westerners who take 40-50% of sugar out of their total average daily calorie. For the purpose of studying diurnal variations in serum glucose, insulin and C-peptide of normal Koreans adults based on ordinary Korean diet, we selected 13 normal Korean male adults and divided them into two groups, Group I (7 persons) and Group II (6 persons). We put Group I on 3,100 kcal and 75% sugar diet, and Group II on 2,100 kcal and 69% sugar diet per day for over 4 days. Serum glucose, insulin and C-peptide were checked every 30 minutes or every hour throughout 2 hour. Results are as follows: 1. As for serum glucose level, in the preprandial fasting state in the morning, mean+-S.D. of Group I was 91.1+-3.2 mg%, while that of Group II is 82.5+-4.4 mg%. Both groups showed peaks of increased glucose level t postprandial 1 hour after each meal. The peak returned to the level shown during the fasting state at postprandial 1 hour after breakfast while the relatively high glucose levels were maintained respectively even for 2 or 3 hours after lunch and dinner. 2. As for serum insults level, Group I showed mean+-S.D. of 14.7+-3.0 muU/ml while Group II shows that of 7.0+-2.6 muU/ml in the fasting state. Group I particularly showed the largest peak from preprandial a half or one and half an hour to postprandial one hour of lunch, and made relatively small peaks (47.7+-10.8 muU/ml) at postprandial 1 hour after breakfast and dinner. No such large peak was marked in Group II, though it showed relatively similar patterns of peak after each meal. 3. As for C-peptide, in the fasting state

  13. A newly developed precise and sensitive radioimmunoassay for clonidine

    International Nuclear Information System (INIS)

    Arndts, D.; Struck, C.J.; Staehle, H.

    1979-01-01

    A new precise and sensitive radioimmunoassay for clonidine has been developed. Synthesis and analysis of the hapten (4-carboxy-clonidine; St 1984) as well as antibody production in rabbits are described in detail. At a final dilution of 1:1000 the resulting immune serum binds 50% of a tritiated clonidine standard containing 1 ng of clonidine. The detection limit of the presented radioimmunoassay for clonidine is 0.1 ng/ml. The coefficient of variation did not exceed 4.3% for any of 7 standard determinations with 5 replicates. There was no relevant crossreactivity of inactive clonidine metabolites apart from 4-OH-clonidine. To avoid any errors from cross-reaction clonidine was selectively and quantitatively extracted into diethylether from unknown plasma samples. Following concentration of the extracts even such low concentrations as 20 pg of clonidine/ml plasma were detectable. With the radioimmunoassay applied in pharmacokinetic studies a maximal clonidine concentration in blood plams of healthy human volunteers was determined to 0.6 ng/ml 1.5 h after oral administration of 150 μg. (orig.) [de

  14. Investigations of serum HPL during pregnancy using two different radioimmunoassays

    International Nuclear Information System (INIS)

    Stracke, H.

    1978-01-01

    The interassay investigations showed that it is absolutely necessary to standardize the HPL antisera as well as the standard sera, as it is otherwise impossible to compare and interpret the findings of different HPL radioimmunoassays. The investigations have shown that in addition to conventional clinical examinations and laboratory test methods (urine estriol determination, DHEAS-dehydroepiandrosterone sulphate test-, urine pregnandiol determination, and determination of heat-resisting alkaline serum phosphatase), HPL concentration determination is a parameter of the nutritive function of the placenta. (orig.) [de

  15. Radioimmunoassay of renin in human renal tissues

    International Nuclear Information System (INIS)

    Wowra, B.

    1981-01-01

    A method has been developed to quantitatively determine renin in human kidney tissue. The angiotensin I split off angiotensinogs by renin was radioimmunologically determined. The renin-renin substrate reaction rate followed a saturation kinetics, as it increased the larger the substrate content in the incubation medium until it acquired a maximum value; the reaction rate decreased with substrate concentrations over 40 mg/ml incubation medium. The discontinuance of the renin reaction after incubation by adding acid, boiling and neutralizing again, gave highest renin values. The RIA scattering was 8.3% for double determination of the same sample, for the determination in different RIA additions 7.0%. The detection limit was 20 pg angiotensin I. A direct comparison of radioimmunoassay and bioassay exhibited a very significant agreement of both methods, where the radioimmunologically measured renin values were on average four times larger than those obtained using biological technique. The definition of the so-called normal values for absolute and specific renin concentration in human kidney tissue enabled one to assess the renin values in various syndromes. (orig./MG) [de

  16. Radioimmunoassay of human prostate-specific acid phosphatase in the diagnosis and follow-up of therapy of prostatic cancer

    International Nuclear Information System (INIS)

    Vihko, P.

    1981-01-01

    The author describes the development of a radioimmunoassay for the determination of serum prostate-specific acid phosphatase and studies its application to the diagnosis and follow-up of therapy of prostatic carcinoma. (Auth./C.F.)

  17. Haloperidol plasmatic levels and their clinical response to the treatment. Comparison between the radioimmunoassay and radioreceptorassay: preliminary data

    Energy Technology Data Exchange (ETDEWEB)

    Cabranes, J A; Almoguera, I; Santos, J L; Prieto, P; Ramos, J A

    1988-06-01

    Schizophrenic patients were treated with haloperidol. Their haloperidol levels in plasma were determined with radioimmunoassay (RIA) and radioreceptor assay (RRA). The results obtained are compared with the clinical improvement. (M.C.B.).

  18. A sensitive radioimmunoassay for colchicine

    International Nuclear Information System (INIS)

    Scherrmann, J.M.; Boudet, L.; Pontikis, R.; Nguyen-Hoang-Nam; Fournier, E.

    1980-01-01

    A sensitive and rapid radioimmunoassay for colchicine was developed using an antibody raised in goats after injection of N-desacetylthiocolchicine conjugated with bovine serum albumin. The incubation time is short and dextran-coated charcoal was used for the separation. The sensitivity of the assay was 0.35 ng/ml urine or serum. A low cross-reactivity was observed with colchicine derivatives and the other drugs tested. The RIA was applied to the measurement of colchicine in the serum of a patient given a 1mg oral dose of the drug. Peak levels of colchicine were attained at 2 hrs. following administration and the drug was rapidly distributed, the concentration decreasing to < 1 ng/ml by 8 hrs. The 24 and 48 hr. concentrations indicated a prolonged excretion of colchicine and a long elimination half-time. (U.K.)

  19. Radioimmunoassay for nortriptyline and amitriptyline

    International Nuclear Information System (INIS)

    Turner, P.

    1977-01-01

    A description has been given (Aherne, G.W.; Marks, V.; Mould, G.; Stout, G.; Lancet; 1214, June 4 (1977)) of a radioimmunoassay (RIA) technique having advantages for monitoring patient response by estimation of plasma concentrations of nortriptyline and amitriptyline. A wide range of monoamine-reuptake-inhibiting drugs is now used in the treatment of depressive illness. There are other analytical techniques such as gas-liquid chromatography which can be used in the estimation of most of these drugs and their major metabolites, as well as for the identification of some other centrally-acting drugs such as benzodiazepines. The chromatographic technique was able to detect the administration of the wrong drug in one comparative study of two antidepressive drugs. Chromatographic and RIA methods therefore both have their own analytical roles according to the clinical or research problem being investigated. (U.K.)

  20. Preparation of albumin radioimmunoassay kit

    International Nuclear Information System (INIS)

    Chen Suoshu; Wang Yanzhen; Wang Zhenshan

    1990-01-01

    This paper presents the preparation of Albumin (Alb) radioimmunoassay kit and its preliminary clinical application. The kit is mainly applied to the measurement of Alb concentration in human urine, adopting second antibody-PEG method. The measurement range is (1-50 μg/ml). The curve obtained with a serially diluted urine sample of high Alb concentration was a straight line. Recovery, detectability, intra- and inter-batch variation coefficients were 95.7%-103.6%, 0.1 μg/ml, 5.8% and 6.4% respectively. The kit was tried out clinically for measuring Alb in urine samples in about 1200 normal individuals and 600 various patients of related renal diseases. The preliminary clinical results show that Alb RIA is conducive to the early diagnosis of kidney function abnormalities

  1. Methadone radioimmunoassay: two simple methods

    International Nuclear Information System (INIS)

    Robinson, K.; Smith, R.N.

    1983-01-01

    Two simple and economical radioimmunoassays for methadone in blood or urine are described. Haemolysis, decomposition, common anticoagulants and sodium fluoride do not affect the results. One assay used commercially-available [1- 3 H](-)-methadone hydrobromide as the label, while the other uses a radioiodinated conjugate of 4-dimethylamino-2,2-diphenylpentanoic acid and L-tyrosine methyl ester. A commercially-available antiserum is used in both assays. Normethadone and α-methadol cross-react to a small extent with the antiserum while methadone metabolites, dextropropoxyphene, dipipanone and phenadoxone have negligible cross-reactivities. The 'cut-offs' of the two assays as described are 30 and 33 ng ml -1 for blood, and 24 and 21 ng ml -1 for urine. The assay using the radioiodinated conjugate can be made more sensitive if required by increasing the specific activity of the label. (author)

  2. Radioimmunoassay method for triiodothyronine and thyroxine

    International Nuclear Information System (INIS)

    Hollander, C.S.

    1975-01-01

    This invention relates to a radioimmunoassay method for triiodothyronine or thyroxine or triiodothyronine and thyroxine present in unextracted serum containing thyroxine binding prealbumin and thyroxine binding globulin. Procedures using 125 I and 131 I are described

  3. Metabolic risk profiles in diabetes stratified according to age at onset, islet autoimmunity and fasting C-peptide

    DEFF Research Database (Denmark)

    Wod, Mette; Yderstræde, Knud B; Halekoh, Ulrich

    2017-01-01

    OBJECTIVE: Islet autoimmunity, age at onset and time to insulin treatment are often used to define subgroups of diabetes. However, the latter criterion is not clinical useful. Here, we examined whether an unbiased stratification of diabetes according to age at onset, fasting C-peptide and GAD......, fasting C-peptide above or below 300 pmol/l (CPEPhigh or CPEPlow), and presence or absence of GADab (GADpos or GADneg). HbA1c, BMI, blood pressure (BP), lipid profile, alanine aminotransferase (ALT) and creatinine were evaluated. RESULTS: GADab were present in 13% of the cohort. Age at onset...... as GADposCPEPhigh; n=327) and patients with type 2 diabetes (GADnegCPEPhigh; n=3,544). Patients with LADA defined an intermediate group with higher HbA1c but otherwise lower cardiometabolic risk than patients with type 2 diabetes. CONCLUSIONS: Our results demonstrate that fasting C-peptide and GADab status...

  4. Validation of a radioimmunoassay for rat insulin

    International Nuclear Information System (INIS)

    Delattre, E.; Boschero, A.C.

    1984-01-01

    A methodological approach that permits, in a radioimmunoassay, the evaluation of rat insulin by using bovine insulin as reference is presented. As in general the technics for radioimmunoassay of different substances follow the same principles (competitive inhibition), we believe that the methodology presented here could be used for evaluation of other hormones when the adequated referential, of know biological activity, is not available. (Author) [pt

  5. Oxytocin determination by radioimmunoassay in cattle. 2

    International Nuclear Information System (INIS)

    Schams, D.; Baumann, G.; Leidl, W.

    1982-01-01

    Oxytocin concentration in jugular vein blood was measured radioimmunologically with a detection limit of 3 pg/ml plasma in male and female cattle. Five bulls were tested; during mating a cow in oestrus with intromission and ejaculation, during mounting a dummy or another bull with ejaculation into an artificial vagina or during false mounts. No increase in oxytocin concentrations could be observed, but stimulation with an electro-ejaculator caused an increase ranging from 5-84 pg/ml after a latent period of 3-5 min. A similar response was observed in two cows following the same procedure. The contact with a bull, false mount or mating with intromission and ejaculation was not followed by a measurable oxytocin release in 5 test cows. The following stimulation techniques, massage of vulva and clitoris, massage of cervix and uterus per rectum, artificial insemination, introduction of a speculum into the vagina or insufflation of air into the vagina were performed with 5 cows and 5 heifers. Insufflation of air into the vagina was the most effective stimulus, eleciting an oxytocin release up to 588 pg/ml. All 5 heiers responded positively, as well as 4 cows in oestrus. The other manipulations cuased an oxytocin response mainly in heifers (whether in oestrus or dioestrus), whereas only one cow in oestrus responded with an oxytocin release. In general, oxytocin concentrations increase about 30-90 s after the start of the stimulus. (author)

  6. A dietary pattern that is associated with C-peptide and risk of colorectal cancer in women.

    Science.gov (United States)

    Fung, Teresa T; Hu, Frank B; Schulze, Matthias; Pollak, Michael; Wu, Tianying; Fuchs, Charles S; Giovannucci, Edward

    2012-06-01

    Higher serum C-peptide concentrations have shown to be associated with an increased risk of colorectal cancer (CRC). Therefore, we used diet information to identify food groups that correlated with fasting serum concentrations of C-peptide and assess the association of this dietary pattern and CRC risk. Major food contributors to fasting C-peptide concentrations were identified with stepwise linear regression in a subsample (n = 833) of women from a large cohort. We then summed the consumption frequency of the major food contributors to form a C-peptide dietary pattern for the entire cohort (n = 66,714). Risk for CRC was computed using Cox proportional hazard model with the C-peptide dietary pattern score as the predictor. In up to 20 years of follow-up, we ascertained 985 cases of CRC and 758 colon cancer. After adjusting for confounders, the C-peptide dietary pattern, characterized by higher meat, fish, and sweetened beverage intake, but lower coffee, high fat dairy, and whole grains intake, showed direct association with CRC risk (RR comparing extreme quintiles = 1.29, 95 % CI = 1.05-1.58, p trend = 0.048). The same comparison was slightly stronger for colon cancer (RR = 1.35, 95 % CI = 1.07-1.70, p trend = 0.009). In stratified analysis, there was no association between the C-peptide dietary pattern and colon cancer among lean and active women. However, for overweight or sedentary women, RR for the same comparison was 1.58 (95 % CI = 1.20-2.07, p trend = 0.002) (p for interaction = 0.007). We derived a dietary pattern that correlated with C-peptide concentrations. This pattern was associated with an increase in colon cancer, especially among women who were overweight or sedentary.

  7. Radioimmunoassay for 2,4-dichlorophenoxyacetic acid

    International Nuclear Information System (INIS)

    Knopp, D.; Dobberkau, H.J.; Nuhn, P.

    1985-01-01

    Antisera to 2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, have been obtained from rabbits following immunization with various 2,4-D-protein conjugates. Employing [ 125 I] 2,4-D-tyramine as the radioligand for the antisera, very poor assay sensitivity was achieved because of a much higher affinity of the antibodies to the tracer. When using [6- 3 H] 2,4-D (specific radioactivity 465 GBq/mmol) a sensitive and specific radioimmunoassay (RIA) for 2,4-D could be developed, which allows determination directly in water, plasma and urine samples. Levels as low as approximately 100 pg (450 femtomoles) of 2,4-D can be detected. The antiserum is fairly specific for 2,4-D. Other related phenoxycarboxylic acids and dichlorophenol showed a cross-reactivity smaller than 10%. After a single administration of 2,4-D (0.91 mg/100 g body weight, orally) to rats, plasma and urine levels were determined at different times. Results correspond to those found in the literature, thus indicating the utility of the RIA. Further applications and limitations are discussed. (orig.)

  8. New sensitive direct radioimmunoassay for human plasma renin and its clinical application

    International Nuclear Information System (INIS)

    Higaki, J.; Ogihara, T.; Imai, N.; Kumahara, Y.; Hontani, S.; Nishiura, M.; Ogawa, H.; Hirose, S.; Murakami, K.

    1984-01-01

    A new sensitive direct radioimmunoassay for human plasma renin has been developed. Renin was purified from Haas' preparation utilizing a pepstatin-C 6 -Sepharose affinity chromatography. Antiserum, prepared by immunizing rabbits with the purified renin, was used for the direct radioimmunoassay at a final dilution of 1:30,000. The antibody was specific for human renal and plasma renin, but did not cross-react with cathepsin D, trypsin, or renins of mouse, dog, and rat. Radioimmunoassay was performed by the double antibody technique using the delayed tracer addition method. In this method, a standard curve was obtained over a range from 0.2 to 8.0 ng/ml. The values from this assay correlated well with total renin activity measured as the generation rate of angiotensin I after trypsin activation, but correlated weakly with active renin activity. This finding disclosed that both active and inactive renin were detected by this method. In normal participants, plasma renin concentration determined by direct radioimmunoassay was increased by standing and furosemide injection. The plasma renin concentration determined by direct radioimmunoassay of patients with essential hypertension was not significantly different from values in normal controls. The values were higher in patients with renovascular hypertension, malignant hypertension and Bartter's syndrome, but lower in patients with primary aldosteronism than in normal controls. 20 references, 7 figures

  9. C peptide and insulin releasing RIA test for the investigation of β cell function in diabetic patients

    International Nuclear Information System (INIS)

    Shi Ailan; Zhu Chengmo; Wang Qiyu; Wang Ping

    1993-01-01

    Results of C-peptide releasing RIA test in 15 normals, and 100 diabetes were summarized and compared with glucose tolerance test and serum insulin for investigating the characteristics in different types of diabetes and evaluating the functional state of islet β cell. In 36 cases of IDDM the fasting blood sugar was significantly increased, and further elevated after eating of bread, but its peak time delay in 2 hours (normalin 1 hour). The level of basal C-peptide is very low, but shows slightly weak on no response after bread stimulating test, all of this denotes that β cell function of islets severely injured. The increasing of fasting blood sugar in 64 cases of NIDDM was lower than those of IDDM. Fasting C-peptide and insulin was normal or increased, their peak value increased after bread stimulation with peak time delayed also at 2 hours. Above results demonstrated that the function of islets B cell decreased but not fully deprived. It is concluded that C-peptide and insulin stimulating test, together with OGTT can accurately assess the islets β cell function, and also have important significance in the pathogenesis, classification and staging, prognostic evaluation and monitoring of therapeutic effects in diabetes

  10. Nature of the Charged-Group Effect on the Stability of the C-Peptide Helix

    Science.gov (United States)

    Shoemaker, Kevin R.; Kim, Peter S.; Brems, David N.; Marqusee, Susan; York, Eunice J.; Chaiken, Irwin M.; Stewart, John M.; Baldwin, Robert L.

    1985-04-01

    The residues responsible for the pH-dependent stability of the helix formed by the isolated C-peptide (residues 1-13 of ribonuclease A) have been identified by chemical synthesis of analogues and measurement of their helix-forming properties. Each of the residues ionizing between pH 2 and pH 8 has been replaced separately by an uncharged residue. Protonation of Glu-2- is responsible for the sharp decrease in helix stability between pH 5 and pH 2, and deprotonation of His-12+ causes a similar decrease between pH 5 and pH 8. Glu-9- is not needed for helix stability. The results cannot be explained by the Zimm-Bragg model and host-guest data for α -helix formation, which predict that the stability of the C-peptide helix should increase when Glu-2- is protonated or when His-12+ is deprotonated. Moreover, histidine+ is a strong helix-breaker in host-guest studies. In proteins, acidic and basic residues tend to occur at opposite ends of α -helices: acidic residues occur preferentially near the NH2-terminal end and basic residues near the COOH-terminal end. A possible explanation, based on a helix dipole model, has been given [Blagdon, D. E. & Goodman, M. (1975) Biopolymers 14, 241-245]. Our results are consistent with the helix dipole model and they support the suggestion that the distribution of charged residues in protein helices reflects the helix-stabilizing propensity of those residues. Because Glu-9 is not needed for helix stability, a possible Glu-9-\\cdots His-12+ salt bridge does not contribute significantly to helix stability. The role of a possible Glu-2-\\cdots Arg-10+ salt bridge has not yet been evaluated. A charged-group effect on α -helix stability in water has also been observed in a different peptide system [Ihara, S., Ooi, T. & Takahashi, S. (1982) Biopolymers 21, 131-145]: block copolymers containing (Ala)20 and (Glu)20 show partial helix formation at low temperatures, pH 7.5, where the glutamic acid residues are ionized. (Glu)20(Ala)20Phe forms a

  11. Evaluation of a radioimmunoassay for the determination of anti-native DNA antibodies. Evaluation d'une technique radio-immunologique pour la detection des anticorps anti-ADN natif

    Energy Technology Data Exchange (ETDEWEB)

    Johanet, C.; Soulie, E.; Absalon, Y.B.; Ocwieja, T.; Abuaf, N. (Hopital Saint-Antoine, 75 - Paris (FR))

    1991-01-01

    The anti-native DNA antibodies were measured by a radioimmunoassay (RIA) type Farr assay in the sera from 648 patients: 108 with active or inactive systemic lupus erythematosus (SLE), 181 with clinical symptoms of another connective tissue disease, 171 with liver diseases, 29 with different pathology and 159 normal sera were obtained from a blood bank. The anti-DNA kit has been calibrated against the first international units/ml. This assay has proved to be sensitive and specific, and appears to be reliable for the diagnosis and follow-up of SLE patients. The authors propose a new reference cut-off level higher than producer's one.

  12. Islet Cell Associated Autoantibodies and C-Peptide Levels in Patients with Diabetes and Symptoms of Gastroparesis

    Directory of Open Access Journals (Sweden)

    Elias S. Siraj

    2018-02-01

    Full Text Available IntroductionIndividuals with diabetes are at increased risk for complications, including gastroparesis. Type 1 diabetes mellitus (T1DM is an autoimmune disorder resulting in decreased beta-cell function. Glutamic acid decarboxylase-65 antibody (GADA is the most commonly used test to assess autoimmunity while C-peptide level is used to assess beta-cell function. Patients with type 2 diabetes mellitus (T2DM, who are GADA positive, are labeled latent autoimmune diabetes in adults (LADA.ObjectiveTo characterize patients with T1 and T2DM who have symptoms of gastroparesis using GADA and C-peptide levels and to look for association with the presence of gastroparesis and its symptom severity.Design113 T1DM and 90 T2DM patients with symptoms suggestive of gastroparesis were studied. Symptom severity was assessed using Gastroparesis Cardinal Symptom Index (GCSI. Serum samples were analyzed for GADA and C-peptide.ResultsDelayed gastric emptying was present in 91 (81% of T1DM and 60 (67% of T2DM patients (p = 0.04. GADA was present in 13% of T2DM subjects [10% in delayed gastric emptying and 20% in normal gastric emptying (p = 0.2]. Gastric retention and GCSI scores were mostly similar in GADA positive and negative T2DM patients. GADA was present in 45% of T1DM subjects [46% in delayed gastric emptying and 41% in normal gastric emptying (p = 0.81]. Low C-peptide levels were seen in 79% T1DM patients and 8% T2DM. All seven T2DM patients with low C-peptide were taking insulin compared to 52% of T2DM with normal C-peptide.ConclusionGADA was present in 13% while low C-peptide was seen in 8% of our T2DM patients with symptoms of gastroparesis. Neither did correlate with degree of delayed gastric emptying or symptom severity.ClinicalTrials.gov IdentifierNCT01696747.

  13. Radioimmunoassay of penicilloyl groups in biological fluids

    International Nuclear Information System (INIS)

    Wal, J-M.; Bories, G.

    1975-01-01

    Penicilloyl-protein conjugates may be formed in man or animals after therapeutic treatment but cannot be detected by the classical microbiological assay methods used for penicillin. Allergies have been noted in consumers of products coming from animals treated with penicillin (milk particularly). Although these compounds present a risk to public health, they passed unnoticed through hygienic food inspection. Therefore a specific and sensitive method was devised for the assay of these derivatives in biological fluids where they can be present in trace amounts. An iodine-125 labelled conjugate has been prepared. Already usable for the detection of antipenicilloyl antibodies in sera of penicillin allergic patients, it has been used for the development of a radioimmunoassay of penicilloyl groups. Assay is done directly on milk, urine and serum without previous extraction and with a detection limit of a few ppb. It permits a rapid, specific and easy to handle determination in the sera of hospital patients as well as in the inspection of animal products at the slaughter house and at the dairy

  14. Radioimmunoassay for chlorinated dibenzo-p-dioxins

    International Nuclear Information System (INIS)

    Albro, P.W.; Chae, K.; Luster, M.I.; Mckinney, J.D.

    1980-01-01

    The invention provides a double-antibody radioimmunoassay method for the determination of chlorinated dibenzo-p-dioxins, particularly, 2,3,7,8-tetrachlorodibenzo-p-dioxin, in environmental samples including animal tissues such as monkey liver and adipose tissues. The limit of detection is approximately 25 picograms for 2,3,7,8-tetrachlorodibenzo-pdioxin. Assuming an appropriate cleanup procedure is used, chlorinated dibenzofurans are the only likely interferences, and these can be distinguished through the use of two antisers of different dibenzo-furan/dibenzodioxin selectivities. The invention includes the preparation of a reproducible antigen, an appropriate radiolabeled hapten, and effective sample extracts. A feature of the assay method is the use of a nonionic detergent (e.g., ''cutscum'' or ''triton x-305'') to solubilize the extremely hydrophobic dibenzo-p-dioxins in a manner permitting their binding by antibodies. The immunoassay is applicable to screening samples in order to minimize the demand for mass spectrometric screening, and to routine monitoring for exposure to known chlorinated dibenzo-p-dioxins in potentially contaminated environments

  15. Automated, computer interpreted radioimmunoassay results

    International Nuclear Information System (INIS)

    Hill, J.C.; Nagle, C.E.; Dworkin, H.J.; Fink-Bennett, D.; Freitas, J.E.; Wetzel, R.; Sawyer, N.; Ferry, D.; Hershberger, D.

    1984-01-01

    90,000 Radioimmunoassay results have been interpreted and transcribed automatically using software developed for use on a Hewlett Packard Model 1000 mini-computer system with conventional dot matrix printers. The computer program correlates the results of a combination of assays, interprets them and prints a report ready for physician review and signature within minutes of completion of the assay. The authors designed and wrote a computer program to query their patient data base for radioassay laboratory results and to produce a computer generated interpretation of these results using an algorithm that produces normal and abnormal interpretives. Their laboratory assays 50,000 patient samples each year using 28 different radioassays. Of these 85% have been interpreted using our computer program. Allowances are made for drug and patient history and individualized reports are generated with regard to the patients age and sex. Finalization of reports is still subject to change by the nuclear physician at the time of final review. Automated, computerized interpretations have realized cost savings through reduced personnel and personnel time and provided uniformity of the interpretations among the five physicians. Prior to computerization of interpretations, all radioassay results had to be dictated and reviewed for signing by one of the resident or staff physicians. Turn around times for reports prior to the automated computer program generally were two to three days. Whereas, the computerized interpret system allows reports to generally be issued the day assays are completed

  16. Radioimmunoassay of canine growth hormone

    International Nuclear Information System (INIS)

    Eigenmann, J.E.; Eigenmann, R.Y.

    1981-01-01

    A sensitive radioimmunoassay (RIA) for canine growth hormone (GH) was developed. Antibodies were elicited in rhesus monkeys. One antiserum exhibited a working titer at a dilution of 1:500 000. Radioiodination was performed enzymatically employing lactoperoxidase. Logit-log transformation and least squares fitting resulted in straight line fitting of the standard curve between 0.39 and 50 ng/ml. Formation of large-molecular [ 125 I]GH during storage caused diminished assay sensitivity. Therefore [ 125 I]GH was re-purified by gel chromatography. Using this procedure, high and reproducible assay sensitivity was obtained. Tracer preparations were used for as long as 3 months after iodination. Diluted plasma from normal and acromegalic dogs resulted in a dose-response curve parallel to the standard curve. Canine prolactin exhibited a cross-reactivity of 2%. The within-assay coefficient of variation (CV) was 3.8 and the between-assay CV was 7.2%. Mean plasma GH concentration in normal dogs was 1.92 +- 0.14 ng/ml (mean +- SEM.) GH levels in acromegalic dogs were appreciably higher. Insulin-induced hypoglycaemia, arginine and ornithine administration resulted in inconsistent and sluggish GH increment. A better response was obtained by injecting a low dose of clonidine. Clonidine administration to hypopituitary dogs resulted in absent or poor GH increment. (author)

  17. Improved radioimmunoassay for human TSH

    International Nuclear Information System (INIS)

    Spencer, C.A.; Nicoloff, J.T.

    1980-01-01

    This study concerns the optimization of the human TSH (h-TSH) radioimmunoassay with special emphasis on reducing the heterogeneity of the 125 I h-TSH tracer. Enzymatic iodination of h-TSH with glucose oxidase/lactoperoxidase was shown to be superior to either low or high dose chloramine-T procedures, producing a high specific activity reagent (70-150 μCi/μg) with minimal evidence of damage. Tracer purification procedures not only affected initial immunoactivity but also storage stability and heterogeneity of the resulting 125 I h-TSH. The assay developed using these technical approaches shows a sensitivity limit of 0.005+-0.001 (S.E.M.) μU/tube; 50% displacement at 0.18+-0.08 (S.E.M.) μU/tube and complete delineation between euthyroid (n=49, 2.44+-0.18 (S.E.M.) mU/l, range 1.00-6.08) and hyperthyroid (n=62, 0.34+-0.02 (S.E.M.) mU/l, range 0.10-0.85), serum h-TSH levels. (Auth.)

  18. Socioecological correlates of energy balance using urinary C-peptide measurements in wild female mountain gorillas.

    Science.gov (United States)

    Grueter, Cyril C; Deschner, Tobias; Behringer, Verena; Fawcett, Katie; Robbins, Martha M

    2014-03-29

    Maintaining a balanced energy budget is important for survival and reproduction, but measuring energy balance in wild animals has been fraught with difficulties. Female mountain gorillas are interesting subjects to examine environmental correlates of energy balance because their diet is primarily herbaceous vegetation, their food supply shows little seasonal variation and is abundant, yet they live in cooler, high-altitude habitats that may bring about energetic challenges. Social and reproductive parameters may also influence energy balance. Urinary C-peptide (UCP) has emerged as a valuable non-invasive biomarker of energy balance in primates. Here we use this method to investigate factors influencing energy balance in mountain gorillas of the Virunga Volcanoes, Rwanda. We examined a range of socioecological variables on energy balance in adult females in three groups monitored by the Karisoke Research Center over nine months. Three variables had significant effects on UCP levels: habitat (highest levels in the bamboo zone), season (highest levels in November during peak of the bamboo shoot availability) and day time (gradually increasing from early morning to early afternoon). There was no significant effect of reproductive state and dominance rank. Our study indicates that even in species that inhabit an area with a seemingly steady food supply, ecological variability can have pronounced effects on female energy balance. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Triiodothyronine radioimmunoassay. Comparison of the different factors between two technics

    International Nuclear Information System (INIS)

    Gehin-Fouque, F.; Etling, N.; Pradelles, P.; Bornet, H.

    1980-01-01

    Triiodothyronine concentration was determined in human serum and in thyroid extracts by two radioimmunoassay technics. Both antibodies, radioactive T 3 , stable T 3 , protein-binding-hormone inhibitors, methods used to separate the free from the bound fractions were different. Each factor from a method was substituted to the homologue of the other method. The results occasionnally showed a variation of 32% in the first method and 50% in the second one. However the results gave a correct interpretation of the triiodothyronine values measured in human serum and in thyroid extracts [fr

  20. Radioimmunoassay for prostatic acid phosphatase in human serum. Methodologic aspects

    Energy Technology Data Exchange (ETDEWEB)

    Pradalier, N; Canal, P; Pujol, A; Fregevu, Y [Groupe de Recherches du Centre Claudius-Regaud, Toulouse (France); Soula, G [Faculte des Sciences Pharmaceutiques, Toulouse (France)

    1982-01-01

    We propose a double antibody radioimmunoassay for human prostatic acid phosphatase (PAP) in serum for diagnosis and management of prostatic adenocarcinoma under treatment. The antigen is purified from human prostatic fluid by a gel-filtration on Sephadex G 100 followed by affinity chromatography on Con A Sepharose. A specific antibody is raised in rabbits and purified by immunoadsorption with a female serum. The described technique offers both radioisotopic sensibility and immunologic specificity. Physiological values determined in the serum of 125 healthy males are below 2 ng/ml. No significative differences are observed with age. The proposed technique also shows significant differences between values evaluated for benign prostatic hyperplasia and prostatic adenocarcinoma.

  1. Quality control in radioimmunoassay for Argentina, Chile, Paraguay and Uruguay

    International Nuclear Information System (INIS)

    Quiroga, S.

    1984-10-01

    The purpose of this project was the development of an External Quality Control Programme on Radioimmunoassay among laboratories from Argentina and other Latinoamerican countries. The purpose of this programme was to improve the performance of the participating laboratories in order to increase the diagnostic value of patient results. The number of returns of this programme (Buenos Aires I) were compared against those of the previous one (Programme I) (Contract 2737/RB) to determine if the objectives were fulfilled. The preparation of the samples and the evaluation of the results of the first six samples were analyzed in the progress report sent on December 30th, 1983 and were reanalysed including late results

  2. Radioimmunoassay of plasma cortisol and its clinical application

    International Nuclear Information System (INIS)

    Ninomiya, Tetsuhiro; Ishitobi, Kazuyuki; Harada, Yoshimichi

    1975-01-01

    A system for the radioimmunoassay of plasma cortisol was developed together with a nonchromatographic method for the assay. An anti-cortisol serum, produced by immunization of rabbits with cortisol-21-hemisuccinate-BSA, proved to have a high affinity and a high specificity for cortisol. The results determined by this system were satisfactory. The nonchromatographic method correlated well with the chromatographic one in normal subjects, who showed 66.2 +- 34.8 ng/ml (case number 22) plasma cortisol levels from 9:00 to 10:00 AM. Various provocation tests were applied to normal subjects and to patients with endocrine disease, and the results were discussed. (auth.)

  3. Assessment of the specificity of norethisterone radioimmunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Bedolla-Tovar, N; Rahman, S A; Cekan, S Z; Diczfalusy, E [Swedish Medical Research Council, Karolinska Hospital, Stockholm

    1978-06-01

    It is concluded that (1) the significance of cross- reaction studies as well as that of the parallelism test for the assessment of the over-all specificity of the assay is limited, (2) a single chromatography prior to the radioimmunoassay proper improves the assay specificity, but may not be sufficient to remove all interfering compounds, (3) a comparison of the direct and chromatographic assay procedures using several antisera is useful for the selection of the relatively most specific radioimmunoassay procedure. In the present study, this is the technique employing either antiserum C or antiserum D, the latter, however, only after chromatography.

  4. Fall in C-Peptide During First 4 Years From Diagnosis of Type 1 Diabetes: Variable Relation to Age, HbA1c, and Insulin Dose.

    Science.gov (United States)

    Hao, Wei; Gitelman, Steven; DiMeglio, Linda A; Boulware, David; Greenbaum, Carla J

    2016-10-01

    We aimed to describe the natural history of residual insulin secretion in Type 1 Diabetes TrialNet participants over 4 years from diagnosis and relate this to previously reported alternative clinical measures reflecting β-cell secretory function. Data from 407 subjects from 5 TrialNet intervention studies were analyzed. All subjects had baseline stimulated C-peptide values of ≥0.2 nmol/L from mixed-meal tolerance tests (MMTTs). During semiannual visits, C-peptide values from MMTTs, HbA1c, and insulin doses were obtained. The percentage of individuals with stimulated C-peptide of ≥0.2 nmol/L or detectable C-peptide of ≥0.017 nmol/L continued to diminish over 4 years; this was markedly influenced by age. At 4 years, only 5% maintained their baseline C-peptide secretion. The expected inverse relationships between C-peptide and HbA1c or insulin doses varied over time and with age. Combined clinical variables, such as insulin-dose adjusted HbA1c (IDAA1C) and the relationship of IDAA1C to C-peptide, also were influenced by age and time from diagnosis. Models using these clinical measures did not fully predict C-peptide responses. IDAA1C ≤9 underestimated the number of individuals with stimulated C-peptide ≥0.2 nmol/L, especially in children. Current trials of disease-modifying therapy for type 1 diabetes should continue to use C-peptide as a primary end point of β-cell secretory function. Longer duration of follow-up is likely to provide stronger evidence of the effect of disease-modifying therapy on preservation of β-cell function. © 2016 by the American Diabetes Association.

  5. Measurement of alpha-fetoprotein in maternal serum: three commercial radioimmunoassay kits and two non-commercial radioimmunoassays compared

    International Nuclear Information System (INIS)

    Forest, J.C.; Verreault, F.; Pouliot, M.

    1982-01-01

    We evaluated three commercial radioimmunoassay kits (Amersham, Dainabot, Clinical Assays) and two non-commercial methods for determining alpha-fetoprotein in maternal serum during pregnancy. All five procedures were found to be acceptable with respect to practicability, sensitivity, linearity, and precision. Similar results were obtained with Dainabot, Clinical Assays, and the two non-commercial methods, but the Amersham method revealed a proportional error, results being about 20% lower than those by the other methods. Use of the international unit system is suggested for reporting results for AFP, to facilitate comparison between methods and laboratories

  6. Radioimmunoassay of thyrotropin concentrated from serum

    International Nuclear Information System (INIS)

    Nisula, B.C.; Louvet, J.P.

    1978-01-01

    A method for concentrating human TSH (hTSH) from serum for use in RIAs is described. The method takes advantage of the affinity of the plant lectin, concanavalin A, for the carbohydrate portion of the hTSH molecule. The hTSH from 2.5 ml serum was adsorbed to concanavalin A covalently linked to sepharose and then radioimmunoassayed using the hTSH antiserum and hTSH for iodination distributed by the National Pituitary Agency. For the RIA standard curve, the hTSH reference preparation was concentrated from a serum wwith undetectable hTSH in order to correct for recovery and to control for nonspecific effects. The percentage of serum hTSH extracted from 2.5 ml serum with the concentration procedure was 76.6 +- 3.4% (mean +- SD). The coefficient of correlation between serum hTSH, determined with the concentration procedure, and serum hTSH determined without was 0.979 (P < 0.001). Over 95% of normal adult men and women had detectable levels of serum hTSH, ranging from < 0.56 to 4.0 μU/ml. The mean of detectable serum hTSH levels in normal adult women (n = 11) was 1.54 +- 1.03 μU/ml (mean +- SD) and in normal men (n = 9) was 2.02 +- 1.15 μU/ml (mean +- SD). Clinically hyperthyroid patients with diffuse and nodular toxic goiters (n = 8) and patients with hypothyroidism secondary to pituitary disease (n = 6), four of whom were taking replacement doses of thyroid hormone, had undetectable serum hTSH levels. Serum hTSH in patients with primary hypothyroidism uniformly exceeded the normal range. This hTSH concentrating procedure enhances the effective sensitivity and, therefore, the clinical utility of the RIA for hTSH in serum

  7. Radioimmunoassay and evaluation for serum SIgA and CG of the hepatopathy patients

    International Nuclear Information System (INIS)

    Liu Junchi; Du Shujun; Lu Jun; Tang Xiaolin; Mao Shaorong

    1995-01-01

    Serum SIgA and CG of 247 hepatopathy (male 140, female 99) are radioimmunoassayed. The Clinical Significance of SIgA, CG for hepatisms is evaluated. The results show that the assay of SIgA, CG has an important significance for the doctor to choose the treatment plans and determine the prognosis

  8. False radioimmunoassay of thyroxine and triiodothyronine in the presence of hormone binding autoantibodies in serum

    International Nuclear Information System (INIS)

    Herrmann, J.; Kley, H.K.; Rudorff, K.H.; Kroell, H.J.; Krueskemper, H.L.

    1976-01-01

    Radioimmuno-assay of thyroxine and triiodothyronine in a 14-year-old girl with primary hypothyroidism and nodular goitre as a result of Hashimoto's thyroiditis gave falsely low values due to the presence of hormone-binding antibodies. Such antibodies occur in Hashimoto's thyroiditis and thyroid carcinoma. Their presence requires special methods for determining these hormones. (orig.) [de

  9. Microfilter paper radioimmunoassay of cortisol and dehydroepiandosterone sulphate in capillary blood

    International Nuclear Information System (INIS)

    Bodrogi, L.; Feher, T.

    1982-01-01

    A microfilter paper method is reported for cortisol and dehydroepiandosterone sulphate radioimmunoassay in fingertip capillary blood. The steroid content of dry blood spot on filter paper is determined. The results are compared to those obtained by conventional technique used for venous blood. Control experiments validated the introduction of this simple and rapid method to assess hormone function in clinical chemistry. (author)

  10. Adsorption columns for use in radioimmunoassays

    International Nuclear Information System (INIS)

    1976-01-01

    Adsorption columns are provided which can be utilized in radioimmunoassay systems such as those involving the separation of antibody-antigen complexes from free antigens. The preparation of the columns includes the treatment of retaining substrate material to render it hydrophilic, preparation and degassing of the separation material and loading the column

  11. Rationale for the development of radioimmunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Roulston, J E; Adam, T [Charing Cross Group of Hospitals, London (UK)

    1978-02-01

    A theoretical study of the principles of radioimmunoassay and allied techniques is presented with a view to the application in practical developmental research. Both equilibrium and sequential saturation methods are discussed and their respective advantages noted. Simple methods for the estimation of the affinity constant by saturation techniques and use of the Scatchard plot are outlined.

  12. Improved radioimmunoassay for thyroid hormone and reagent

    International Nuclear Information System (INIS)

    1980-01-01

    Improvements in the radioimmunoassay of the thyroid hormones, thyroxine or triiodothyronine, are described. Hydrolyzed cross-linked polyacrylamide particles covalently bonded against the thyroid hormone are employed as solid phase substrates for the thyroid hormone antibodies. The polyacrylamide particles are dyed yellow or blue to facilitate the various manipulative steps during the radioimmunoassay. The particles are characterized by their ability to form stable hydrophilic suspensions. As a result the reaction mixture, during which thyroid hormone is separated from serum proteins and competitive binding in the presence of radioactive tracer with the antibody occurs, requires no agitation to maintain the desired homogeneous condition. This is in contrast to the settling problems experienced with cellulose, dextran and glass particles. In addition, the non-specific binding property of the polyacrylamide particles is so low that the initially separated solid phase particles following incubation can be directly measured for radioactivity levels without any initial washings thus increasing the speed and convenience of the assay procedure. Details of the preparation of the dyed, hydrolyzed polyacrylamide particles, the coupling of antiserum to these particles and the radioimmunoassay procedure are given. Data obtained from the radioimmunoassays of hypothyroid, euthyroid and hyperthyroid sera demonstrated the satisfactory performance of the assay. (U.K.)

  13. Evaluation of radioimmunoassay data by a minicomputer

    International Nuclear Information System (INIS)

    Venot, A.; Ingrand, J.; Roucayrol, J.C.; Valeyre, J.; Deltour, G.

    1977-01-01

    A program is proposed for routine use in every radioimmunoassay laboratory part of a bigger unit such as a department of nuclear medicine. Its main features are maniability and ability to avoid undue effects of outlying experimental values. A non specialized technician can operate himself, the data being fed off-line by a paper tape into a Multi 8 Intertechnique minicomputer [fr

  14. C-Peptide, Baseline and Postprandial Insulin Resistance after a Carbohydrate-Rich Test Meal - Evidence for an Increased Insulin Clearance in PCOS Patients?

    Science.gov (United States)

    Stassek, J; Erdmann, J; Ohnolz, F; Berg, F D; Kiechle, M; Seifert-Klauss, V

    2017-01-01

    Introduction Known characteristics of patients with PCOS include infertility, menstrual disorders, hirsutism and also often insulin resistance. These symptoms increase with increasing body weight. In the LIPCOS study ( L ifestyle I ntervention for Patients with Polycystic Ovary Syndrome [ PCOS ]) long-term changes of the PCOS in dependence on pregnancy and parenthood were systematically assessed. In the framework of the LIPCOS study, PCOS patients were given a standardised carbohydrate-rich test meal in order to examine glucose homeostasis and insulin secretion. The results were compared with those of a eumenorrhoeic control group who all had corresponding BMI values and corresponding ages. Methods and Patients 41 PCOS patients (without diabetes) and 68 controls received a standardised carbohydrate-rich test meal (260 kcal, 62 % carbohydrates, 32 % fat, 6 % proteins) in order to generate a submaximal insulin and glucose stimulation. The values were determined at baseline and postprandial after 60, 120 and 180 minutes. In addition, the corresponding C-peptide levels were recorded. Results In the PCOS patients (n = 41), the insulin secretion test after a standardised test meal showed almost identical baseline and postprandial insulin levels when compared with those of the age- and BMI-matched eumenorrhoeic controls (n = 68). In the PCOS patients, the baseline and postprandial glucose levels were significantly elevated (92.88 ± 10.28 [PCOS] vs. 85.07 ± 9.42 mg/dL [controls]; p PCOS patients formally exhibit a higher fasting insulin resistance than controls. In spite of the higher stimulated C-peptide levels, the insulin levels did not increase more strongly with increasing glucose levels than in controls which may be indicative of a higher insulin clearance in PCOS patients.

  15. TRH radioimmunoassay for unextracted human urine

    International Nuclear Information System (INIS)

    Mitsuma, Terunori; Hirooka, Yoshibumi; Nihei, Noriyuki

    1975-01-01

    The authors developed a TRH radioimmunoassay for unextracted human urine using anti-TRH antibody produced by immunization of rabbits with a TRH-bis-diazotized-bovine serum albumin conjugate. The antibody had no crossreactivity with TRH analogues, amino acids or pituitary hormones, but with L or DL-Aze3-TRH. TRH was radioiodinized by Greenwood-Hunter's method, followed by purification on Sephadex G-10. Inactivation of TRH by serum was well documented. The authors found however that this inactivation of TRH could be prevented by adjusting the pH to 3.0 or by keeping the temperature between 4 0 C and -20 0 C. All assay procedures were performed in 0.01 M phosphate buffer with 0.15 M NaCl (pH 7.5) at 4 0 C. Free and bound forms were separated with a second antibody system. In this system, sensitivity was 0.01 ng/tube, recovery was approximately 100%, intrassay reproducibility was 3.2% and interassay variation was 9.8%. TRH levels in urine measured with this system were undetectable to 9.0 ng/ml in normal subjects, undetectable in hyperthyroid patients or a tertiary hypothyroid patient and 13 to 24 ng/ml in primary hypothyroid patients. Approximately 6 percent of the intravenously administered TRH was excreted into the urine within 12 hours following administration in a normal subject. As a result this assay system is quite attractive for clinical determination as well as research application. (Evans, J.)

  16. Postprandial C-Peptide to Glucose Ratio as a Marker of β Cell Function: Implication for the Management of Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Yoshifumi Saisho

    2016-05-01

    Full Text Available C-peptide is secreted from pancreatic β cells at an equimolar ratio to insulin. Since, in contrast to insulin, C-peptide is not extracted by the liver and other organs, C-peptide reflects endogenous insulin secretion more accurately than insulin. C-peptide is therefore used as a marker of β cell function. C-peptide has been mainly used to assess the presence of an insulin-dependent state for the diagnosis of type 1 diabetes. However, recent studies have revealed that β cell dysfunction is also a core deficit of type 2 diabetes, and residual β cell function is a key factor in achieving optimal glycemic control in patients with type 2 diabetes. This review summarizes the role of C-peptide, especially the postprandial C-peptide to glucose ratio which likely better reflects maximum β cell secretory capacity compared with the fasting ratio in assessing β cell function, and discusses perspectives on its clinical utility for managing glycemic control in patients with type 2 diabetes.

  17. Radioimmunoassay - renin - angiotensin. Principles of radioimmunoassay and their application in measuring renin and angiotensin

    Energy Technology Data Exchange (ETDEWEB)

    Krause, D K; Hummerich, W; Poulsen, K [eds.

    1978-01-01

    Typical pitfalls such as impurity of 'standard', tracer damage, crossreactivity of antiserum, unspecific binding of protecting proteins, blank effects with negative results, charcoal stripping, invisible coprecipitate or uncertainty in the analysis of the calibration curve (graph, logit-log, polynormal or spline function) can occur in any type of radioimmunoassay; they are detailed in the general part of this book. The special position occupied by radioimmunological quantification of parameters of the renin-angiotensin system creates additional, even more serious problems. While the radioimmunological determination of the decapeptide angiotensin I no longer causes major obstacles, measurement of the biologically active octapeptide angiotensin II is still only possible in a few centers. The (indirect) determination of plasma renin is characterized by a situation where the enzyme renin may be clearly defined in theory as a specific 10-11-leucine-leucine-endopeptidase cleaving only a decapeptide, but the actual renin assay, however, measures various forms of renin and other angiotensin-forming (or angiotensin-destroying) enzymes at the same time.

  18. Radioimmunoassay of Alb, β2-M and THP

    International Nuclear Information System (INIS)

    Xie Zhiyuan; Li Shengqi; Ren Shusheng; Chen Yuying

    1993-01-01

    The combined determination of β 2 -M, THP, Alb, IgG may be used as the sensitive indication of the early degeneration of kidney function. The authors observed 107 cases, and found that the anomalous examine-out ratios of hemorrhage β 2 -M and UTHP are 50.75% and 65.67% respectively, 1.5-2.3 times higher than the C cr animals examine-out ratio. The radio-immunoassay of β 2 -M and THP is a better measure for discovering light kidney function injury in early period than C cr method. The clinical value of the radio-immunoassay of β 2 -M, THP is obviously better than the traditional and classical method. The diseases of anybody system may influence the kidney function through various mechanisms. The retrogression of kidney tissue of the patients in old-and mid-age leads to decrease of kidney function. The combination of β 2 -M and THP has the highest anomalous examine-out ratios of kidney function; the next is urine Alb

  19. Radioimmunoassay of TSH subunits in thyroid diseases and endocrine opthalmopahty

    International Nuclear Information System (INIS)

    Eder, W.

    1982-01-01

    Highly sensitive radioimmunoassays of hTSH sub-units were developed. The hormone preparations were labelled with 125-iodine according to a modified chloramine -T method, and purified by chromatography using biogel P6 and P60. Rabbit antisera were used as antibodies. Separation of the antibody-bound and of the free antigens was carried out via the double antibody method. The antiserum required for this purpose was obtained from a goat. The sensitivity of the assay was influenced by changing the protein content of the buffer, the incubation volume, the tracer amounts, the incubation time and the incubation temperature. For hTSH-α, the lowest detectable limit was found to be 50 pg/ml, for hTSH-#betta# 20 pg/ml. Thus, the sub-units could be determined for 98% of the patients under review. The #betta#-TSH radioimmunoassay is largely specific, TSH cross-reacts to a degree of 5%. The computerized evoluation was carried out by means of Spline approximation using the Siemens 4004 computer. Precision and accurateness are in compliance with generally accpted criteria. The serum levels of α and #betta# sub-units showed no discordancy with regard to TSH. In all groups of patients examined, the levels of the hormone-specific #betta#-chain were found to be exclusively dependent upon the actual thyroid activity. (orig.) [de

  20. Radioimmunoassay of prostaglandin F in plasma of pregnant women

    International Nuclear Information System (INIS)

    Albert, P.

    1980-01-01

    The aim of this dissertation was to determine quantitatively prostaglandin-F in the plasma of pregnant women in order to obtain further knowledge on changes in PG-F during pregnancy, in particular during the last three months. The plasma of women with clinically normal pregnancies was taken. Prior to radioimmunoassay the plasma was extracted (separation of PG from other plasma components) and chromatography carried out (group separation of PG). The efficiency of this process, as measured by the recovery rate of 3 H-PGF, lies between 60.99% and 93.01% for extraction and between 80.58% and 92.16% for chromatography. The plasma was extracted and analysed chromatographically for the assay. The radioimmunoassay was carried out according to the procedure recommended by the manufacturer. A calibration curve was produced without difficulty. The results of the examination of plasma samples were unsatisfactory because of the low sensitivity of the assay; PG-F values of the same order were obtained for all weeks of pregnancy. (orig./MG) [de

  1. Programs for radioimmunoassays and radioreceptorassays using SPSS-X.

    Science.gov (United States)

    Amador, A G; Hodges, S L

    1989-01-01

    Two sets of programs written using SPSS-X, and designed for the analysis of data obtained by radioimmunoassay or radioreceptorassay are presented. The main advantages of the programs are that they are easily edited, their commands are simple and logical, and they can be used for any type of radioimmunoassay or radioreceptorassay, respectively. The programs for radioimmunoassay can also be used for fluorescenceimmunoassay and luminescenceimmunoassay.

  2. Radioimmunoassay of deoxynivalenol in wheat and corn

    International Nuclear Information System (INIS)

    Xu, Y.C.; Zhang, G.S.; Chu, F.S.

    1986-01-01

    With the availability of antibody against deoxynivalenol triacetate (DON-triacetate), a radioimmunoassay (RIA) for DON in wheat was developed. DON is extracted from the sample with acetonitrile-water defatted with hexane, and then reacted with acetic anhydride to form DON-triacetate. The reaction mixture is loaded onto a C-18 cartridge to remove excess reagents and impurities. Acetylated DON is eluted from the cartridge with 50% methanol in water, and then analyzed by radioimmunoassay utilizing antiserum against DON-triacetate and tritiated DON-triacetate. Overall recovery for DON added to wheat between 50 and 5000 ppb was 86% with a standard deviation of 7% and coefficient of variation of 8%. The limit of detection for DON was about 20 ppb. Analysis of 12 naturally contaminated wheat, corn, and mixed feed samples for DON revealed that RIA results agreed well with thin layer chromatographic analyses performed by other laboratories

  3. 125I Radioimmunoassay of serum ursodeoxycholyl conjugates

    International Nuclear Information System (INIS)

    Hill, A.; Ross, P.E.; Bouchier, I.A.D.

    1983-01-01

    A radioimmunoassay for serum ursodeoxycholic conjugates using an iodine-125 ligand has been developed. The bile acid was present in normal fasting serum (0.19 +- SD 0.19 μmol/l, n=24) and 2-hour post-prandial serum (0.8 +- SD 0.8 μmol/l, n=16). Gallstone patients undergoing oral ursodeoxycholic acid therapy had significantly higher post-prandial serum levels (21.5 +- SD 14.0 μmol/l, n=15) by radioimmunoassay. Gas liquid chromatography analysis indicated that in normal serum ursodeoxycholic acid was totally conjugated, whereas sera from gallstone patients contained a proportion as the free bile acid (10.2 +- SD 8.1 μmol/l, n=15). Following an oral dose of ursodeoxycholic acid, both unconjugated and conjugated forms of the bile acid appeared in the serum of healthy individuals. (Auth.)

  4. Radioimmunoassay of human Hageman factor (factor XII)

    International Nuclear Information System (INIS)

    Saito, H.; Ratnoff, O.D.; Pensky, J.

    1976-01-01

    A specific, sensitive, and reproducible radioimmunoassay for human Hageman factor (HF, factor XII) has been developed with purified human HF and monospecific rabbit antibody. Precise measurements of HF antigen were possible for concentrations as low as 0.1 percent of that in normal pooled plasma. A good correlation (correlation coefficient = 0.82) existed between the titers of HF measured by clot-promoting assays and radioimmunoassays among 42 normal adults. Confirming earlier studies, HF antigen was absent in Hageman trait plasma, but other congenital deficient plasmas, including those of individuals with Fletcher trait and Fitzgerald trait, contained normal amounts of HF antigen. HF antigen was reduced in the plasmas of patients with disseminated intravascular coagulation or advanced liver cirrhosis, but it was normal in those of patients with chronic renal failure or patients under treatment with warfarin. HF antigen was detected by this assay in plasmas of primates, but not detectable in plasmas of 11 nonprimate mammalian and one avian species

  5. The Association between Newborn Regional Body Composition and Cord Blood Concentrations of C-Peptide and Insulin-Like Growth Factor I.

    Directory of Open Access Journals (Sweden)

    Emma M Carlsen

    Full Text Available Third trimester fetal growth is partially regulated by C-peptide and insulin-like growth factor I (IGF-I. Prenatal exposures including maternal obesity and high gestational weight gain as well as high birth weight have been linked to subsequent metabolic disease. We evaluated the associations between newborn regional body composition and cord blood levels of C-peptide and IGF-I.We prospectively included obese and normal-weight mothers and their newborns; cord blood was collected and frozen. Analyses of C-peptide and IGF-I were performed simultaneously, after recruitment was completed. Newborn regional body composition was assessed with dual-energy X-ray absorptiometry scanning (DXA within 48 hours of birth.Three hundred thirty-six term infants were eligible to participate in the study; of whom 174 (52% infants had cord blood taken. Total, abdominal and arm and leg fat mass were positively associated with C-peptide (p < 0.001. Arm and leg fat mass was associated with IGF-I concentration: 28 g [95% confidence interval: 4, 53] per doubling of IGF-I. There was no association between total or abdominal fat mass and IGF-I. Fat-free mass was positively associated with both C-peptide (p < 0.001 and IGF-I (p = 0.004.Peripheral fat tissue accumulation was associated with cord blood C-peptide and IGF-I. Total and abdominal fat masses were related to C-peptide but not to IGF-I. Thus, newborn adiposity is partially mediated through C-peptide and early linear growth is associated with IGF-I.

  6. Folic acid derivatives for use in radioimmunoassay

    International Nuclear Information System (INIS)

    Ali, A.

    1981-01-01

    The chemical preparation of two folic acid derivatives, labelled with 125 I or 131 I, is described for use in radioimmunoassay of folic acid and its metabolites in biological fluids such as blood serum. Labelled compounds of the present invention more closely resemble folic acid in that they have glutamic acid in the terminal position. Examples of the use of these compounds in three different assays are given. (U.K.)

  7. Significance and radioimmunoassay of gastric inhibitory polypeptide

    International Nuclear Information System (INIS)

    Zheng Ping; Zeng Minde; Yuan Jimin

    1995-01-01

    We have established the GIP Radioimmunoassay which has high sensitivity and specificity by labelling with iodogen and purified with HPLC. Using this method, the plasma GIP level was measured in 64 cases of which there are 10 normal individuals, 25 cases of diabetes and 29 cases of liver cirrhosis . The results showed that the plasma GIP level was significantly increased in patients with liver cirrhosis and correlated to degree of glucose tolerance damage

  8. Radioimmunoassay of ovine alpha-fetoprotein

    International Nuclear Information System (INIS)

    Lai, P.C.W.

    1978-01-01

    Highly purified ovine alpha-fetoprotein (AFP) was used both for radioisotope labelling and as the reference standard in the double antibody radioimmunoassay of ovine AFP. The sensitivity of the assay is 2 ng/ml which is about 8000 times more sensitive than radioimmunodiffusion assay. The assay is of sufficient sensitivity to quantitate AFP in normal adult sheep serum, pregnancy serum, amniotic fluid and fetal lamb serum. (Auth.)

  9. Status of radioimmunoassay services in the Philippines

    International Nuclear Information System (INIS)

    Valencia, I.G.; Bonoan, L.S.; Medina, V.F.O.

    1986-01-01

    This paper discusses the participation of the Philippines as a member state of the International Atomic Energy Agency (IAEA) in the Regional Cooperation Agreement (RCA) project on radioimmunoassay of thyroid related hormones in Asia and the Pacific. Seven of the twenty-three radioassay laboratories engaged in RIA work have signified their agreement to participate in the program. The proposed organization and function structure of the project, the projected RIA use and strategy to popularize use of RIA are given. (ELC)

  10. Radioimmunoassay of measles virus antibodies in SSPE

    International Nuclear Information System (INIS)

    Jankowski, M.A.; Gut, W.; Kantoch, M.

    1982-01-01

    A sensitive radioimmunoassay (RIA) was introduced for detecting measles virus IgG and IgM antibodies. The hyperimmune response to the measles virus could be demonstrated more accurately by RIA than by haemagglutination inhibition (HI). The ratio between RIA and HI antibody titres was decidedly higher in sera and cerebrospinal fluids of patients with subacute sclerosing panencephalitis than in those of other groups tested. (author)

  11. Carcinoembryonic antigen radioimmunoassay in hepatic tumor

    International Nuclear Information System (INIS)

    Aburano, Tamio; Tonami, Norihisa; Hisada, Kinichi

    1976-01-01

    Carcinoembryonic antigen (CEA) radioimmunoassay with the sandwich method was performed in addition to both α 1 -fetoprotein (AFP) radioimmunoassay and liver scintigraphy to elevate the diagnostic accuracy of hepatic tumor in nuclear medicine. All of the ten healthy controls and 47 of 52 cases with benign disease showed a CEA titer less than 2.5ng/ml. 78 of 188 cases (41%) of malignant disease showed a titer of over 2.5ng/ml; however most positive cases were metastatic, especially to the liver. In metastatic liver cancer, thirtythree out of 46 cases (72%) showed a strongly positive CEA titer. Over 5ng/ml was taken as the lower limit for predicting metastasis to the liver. On the other hand, in primary liver cancer thirty-two out of 35 cases (91%) showed a strongly positive AFP titer over 200ng/ml, although only one case showed a CEA titer over 5ng/ml. Seven cases (15%) of metastatic liver cancer also showed a strongly positive AFP titer; however six of these positive cases showed a CEA titer over 5ng/ml. In metastatic liver cancer, eleven out of 46 cases (24%) showed no clearcut focal defects on liver scintigram. Nine of these negative cases showed a CEA titer over 5ng/ml, and at subsequent operation metastatic liver lesions were found. The overall diagnostic accuracy for detecting metastatic liver cancer with a combination of both methods was 95%. CEA radioimmunoassay was found to be useful for the elucidation of the nature of focal hepatic lesions in addition to AFP radioimmunoassay, and moreover could be used as an adjunct to liver scintigraphy for the detection of metastatic lesions in the liver. (auth.)

  12. Radioimmunoassay of parathyroid hormone: past and future

    International Nuclear Information System (INIS)

    Yalow, R.S.

    1986-01-01

    In this report on radioimmunoassay of parathyroid hormone (iPTH) it was shown that the rate of disappearance of iPTH from plasma differed markedly in patients with primary hyperthyroidism or those with uremia and secondary hyperparathyroidism and that for each patient the rate of disappearance depended on the antiserum used for assay. The heterogeneity of iPTH in plasma was soon rapidly confirmed in many laboratories. (Auth.)

  13. Studies on the radioimmunoassay of thyroid hormones

    International Nuclear Information System (INIS)

    Kim, J.R.; Awh, O.D.; Park, K.B.; Kim, Y.S.

    1980-01-01

    To establish radioimmunoassay (RIA) systems of 3,5,3'-triiodo-L-thyronine (T 3 ) and thyroxine (T 4 ), various experiments such as 125 I labelling, antibody raising, preparation of hormone-free sera and efficient separations of the free hormones from those of antibody bound etc. were conducted. By optimizing many factors, assay systems were successfully established. Some detailed methodological aspects were described. (author)

  14. Human aldolase B subunit-specific radioimmunoassay

    International Nuclear Information System (INIS)

    Asaka, M.; Alpert, E.

    1983-01-01

    A radioimmunoassay was developed for the direct quantification of aldolase B in human serum and tissues. The method is a double-antibody radioimmunoassay technique using radioiodinated aldolase B homopolymer as ligand, chicken antibodies to aldolase B and rabbit antibodies to chicken IgG. This radioimmunoassay was shown to be specific for the aldolase B subunit, with no cross-reactivity with either human aldolase A subunit or homopolymeric human aldolase C (C 4 ). The lowest measurable amount by this method was 2 ng/ml. Aldolase B is predominantly found in normal liver tissue, with relatively-high aldolase B levels also observed in kidney. Aldolase B levels in the serum obtained from 11 normal subjects ranged from 23 to 38 ng/ml, with a mean of 28.5 +- 9.2 (S.D.) ng/ml. Almost all of patients with hepatitis had serum aldolase B levels greater than 30 ng/ml. In cancer patients, serum aldolase B was slightly elevated in patients with metastatic liver cancer and primary lever cell carcinoma, whereas no elevation of serum aldolase B was shown in patients without liver metastasis. (Auth.)

  15. The production of antibodies for radioimmunoassay

    International Nuclear Information System (INIS)

    Court, G.

    1975-01-01

    Three factors which affect the outcome of any immunisation schedule designed to produce antisera for radio-immunoassay, the antigen, the method of immunisation and the choice of animal are considered. Several factors concerning the nature of the antigen are dealt with, for example, the molecular size and immunogenicity of the antigen. It is noted that the larger polypeptide and proteins are sufficiently immunogenic to elicit a useful antibody response alone and that whilst substances with molecular weights of less than 2000 may produce a response alone they will probably produce a better one if they are conjugated (chemically coupled) to a much larger molecule. The method of immunisation is discussed including a consideration of the use of adjuvant and the route and timing of injections. It is noted that antisera showing the relevant properties for radio-immunoassay are rarely produced without emulsification of the immunogen in Freund's adjuvant although this is not an absolute requirement for antibody production. Data are presented comparing the intramuscular and multiple intradermal routes of injection. The results, however, fail to demonstrate any major advantage for either method although the latter may be more economical, producing high titre antisera with relatively small amounts of immunogen. Because of their convenience rabbits are generally the first choice of animal for raising antisera for radioimmunoassay although guinea pigs, chickens and sheep have been used successfully in many cases

  16. Pengaruh Transplantasi Allograf Pancreatic Stem Cell terhadap Kadar Insulin dan C-Peptide Tikus Putih Penderita Diabetes Melitus Tipe I

    Directory of Open Access Journals (Sweden)

    Boedi Setiawan

    2016-09-01

    Full Text Available Diabetes mellitus is one of the degenerative diseases in which the therapy still remains unresolved and is still a serious threat to the global health, including to the health of Indonesian people. The aim of this study was to describe the level of insulin and C-peptide in diabetes mellitus type I white rats treated with pancreatic stem cell allograft through intrapancreatic laparotomy. This study was conducted at the Institute of Tropical Diseases, Universitas Airlangga, Surabaya in a 6 month period (July–December 2014. Twelve male white rats Rattus novergicus Wistar strain, were randomly divided into two groups. The first group (P0 was injected by alloxan, 150 mg/kg body weight, without stem cell therapy. Another group was injected by alloxan, 150 mg/kg body weight, and was treated with 1x106/kg body weight pancreatic stem cell throughintrapancreatic laparotomy (P1. The experiment was finalized on the 31th day of the experiment. The results showed that the blood glucose levels at the end of experiment were highly significantly different p<0.01 between the treatment group that received stem cell therapy (P1 and P0 positive control, although the average value of blood glucose levels was not as normal as on the first day. C-peptide and insulin levels of P0 and P1 group differed significantly (p<0.01. It can be concluded that stem cell therapy through intrapancreatic laparotomy can reduce blood glucose levels and increase the levels of C-peptide and insulin.

  17. Fall in C-peptide during first 2 years from diagnosis: evidence of at least two distinct phases from composite Type 1 Diabetes TrialNet data.

    Science.gov (United States)

    Greenbaum, Carla J; Beam, Craig A; Boulware, David; Gitelman, Stephen E; Gottlieb, Peter A; Herold, Kevan C; Lachin, John M; McGee, Paula; Palmer, Jerry P; Pescovitz, Mark D; Krause-Steinrauf, Heidi; Skyler, Jay S; Sosenko, Jay M

    2012-08-01

    Interpretation of clinical trials to alter the decline in β-cell function after diagnosis of type 1 diabetes depends on a robust understanding of the natural history of disease. Combining data from the Type 1 Diabetes TrialNet studies, we describe the natural history of β-cell function from shortly after diagnosis through 2 years post study randomization, assess the degree of variability between patients, and investigate factors that may be related to C-peptide preservation or loss. We found that 93% of individuals have detectable C-peptide 2 years from diagnosis. In 11% of subjects, there was no significant fall from baseline by 2 years. There was a biphasic decline in C-peptide; the C-peptide slope was -0.0245 pmol/mL/month (95% CI -0.0271 to -0.0215) through the first 12 months and -0.0079 (-0.0113 to -0.0050) from 12 to 24 months (P < 0.001). This pattern of fall in C-peptide over time has implications for understanding trial results in which effects of therapy are most pronounced early and raises the possibility that there are time-dependent differences in pathophysiology. The robust data on the C-peptide obtained under clinical trial conditions should be used in planning and interpretation of clinical trials.

  18. The role of insulin C-peptide in the coevolution analyses of the insulin signaling pathway: a hint for its functions.

    Directory of Open Access Journals (Sweden)

    Shuai Wang

    Full Text Available As the linker between the A chain and B chain of proinsulin, C-peptide displays high variability in length and amino acid composition, and has been considered as an inert byproduct of insulin synthesis and processing for many years. Recent studies have suggested that C-peptide can act as a bioactive hormone, exerting various biological effects on the pathophysiology and treatment of diabetes. In this study, we analyzed the coevolution of insulin molecules among vertebrates, aiming at exploring the evolutionary characteristics of insulin molecule, especially the C-peptide. We also calculated the correlations of evolutionary rates between the insulin and the insulin receptor (IR sequences as well as the domain-domain pairs of the ligand and receptor by the mirrortree method. The results revealed distinctive features of C-peptide in insulin intramolecular coevolution and correlated residue substitutions, which partly supported the idea that C-peptide can act as a bioactive hormone, with significant sequence features, as well as a linker assisting the formation of mature insulin during synthesis. Interestingly, the evolution of C-peptide exerted the highest correlation with that of the insulin receptor and its ligand binding domain (LBD, implying a potential relationship with the insulin signaling pathway.

  19. The influence of body mass index and age on C-peptide at the diagnosis of type 1 diabetes in children who participated in the diabetes prevention trial-type 1.

    Science.gov (United States)

    Sosenko, Jay M; Geyer, Susan; Skyler, Jay S; Rafkin, Lisa E; Ismail, Heba M; Libman, Ingrid M; Liu, Yuk-Fun; DiMeglio, Linda A; Evans-Molina, Carmella; Palmer, Jerry P

    2018-05-01

    The extent of influence of BMI and age on C-peptide at the diagnosis of type 1 diabetes (T1D) is unknown. We thus studied the impact of body mass index Z-scores (BMIZ) and age on C-peptide measures at and soon after the diagnosis of T1D. Data from Diabetes Prevention Trial-Type 1 (DPT-1) participants C-peptide measures with BMIZ and age in 2 cohorts: oral glucose tolerance tests (OGTTs) at diagnosis (n = 99) and mixed meal tolerance tests (MMTTs) C-peptide from OGTTs (n = 99) at diagnosis and MMTTs (n = 80) after diagnosis were positively associated with BMIZ and age (P C-peptide measures. In an example, 2 individuals with identical AUC C-peptide values had an approximate 5-fold difference in values after adjustments for BMIZ and age. The association between fasting glucose and C-peptide decreased markedly when fasting C-peptide values were adjusted (r = 0.30, P C-peptide measures are strongly and independently related to BMIZ and age at and soon after the diagnosis of T1D. Adjustments for BMIZ and age cause substantial changes in C-peptide values, and impact the association between glycemia and C-peptide. Such adjustments can improve assessments of β-cell impairment at diagnosis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Anti-DNA antibody in serum measured by radioimmunoassay (Farr technique)

    Energy Technology Data Exchange (ETDEWEB)

    Manthorpe, R; Palit, J; Bendixen, G [Rigshospitalet, Copenhagen (Denmark)

    1978-01-01

    The anti DNA antibody determination in serum is increasingly used because it supports the diagnosis of systemic lupus erythematosus (SLE) with high selectivity. The present work evaluates several of the technical variables of the Farr radioimmunoassay for anti-DNA antibody determination and describes a recommendable procedure. The most important sources of error are emphasized and the range for normal blood donors and a group of hospital patients without SLE is given.

  1. Anti-DNA antibody in serum measured by radioimmunoassay (Farr technique)

    International Nuclear Information System (INIS)

    Manthorpe, R.; Palit, J.; Bendixen, G.

    1978-01-01

    Anti-DNA antibody determination in serums is increasingly used because it supports the diagnosis of systemic lupres erythematosus (SLE) with high selectivity. The present work evaluates several of the technical variables of the Farr radioimmunoassay for anti-DNA antibody determination and describes a recommendable procedure, emphasizes the most important sources of error and gives the range of normal blood donors and a group of hospital patients without SLE. (author)

  2. Glucose, insulin and C-peptide secretion in obese and non obese women with polycystic ovarian disease.

    Science.gov (United States)

    Mahabeer, S; Naidoo, C; Joubert, S M

    1990-06-01

    Plasma glucose, immunoreactive insulin (IRI) and C-peptide responses during oral glucose tolerance testing (OGTT) were evaluated in 10 non obese women with polycystic ovarian disease (NOB-PCOD) and 10 obese women with polycystic ovarian disease (OB-PCOD). Mean plasma glucose response at 120 minutes in OB-PCOD showed impaired glucose tolerance. Also in this group, 1 patient had frank diabetes mellitus, whilst 3 other patients had impaired glucose tolerance 1 NOB-PCOD patient had impaired glucose tolerance. Mean plasma glucose levels and mean incremental glucose areas were higher in the OB-PCOD at all time intervals and reached statistical significance at 60 and 90 minutes. Mean plasma IRI levels were also higher in OB-PCOD at all time intervals, and reached statistically significant higher levels at 0, 60 and 90 minutes. Mean serum C-peptide valves were also higher at all time intervals in OB-PCOD. The relationship between acanthosis nigricans, obesity and PCOD was also analysed. It is evident from this study that obesity has a significant negative impact on the overall carbohydrate status in women with PCOD.

  3. The Association of Fasting Glucose, Insulin, and C-Peptide, with 19-Year Incidence of Coronary Heart Disease in Older Japanese-American Men; the Honolulu Heart Program

    Directory of Open Access Journals (Sweden)

    Nazneem Wahab

    2018-04-01

    Full Text Available The role of fasting glucose, insulin levels, and C-peptide in coronary heart disease (CHD in non-diabetic individuals remains uncertain. We examined the association between fasting glucose, insulin and C-peptide with the long-term incidence of CHD in Japanese-American men. In 1980–1982, from a random sample of the Honolulu Heart Program men (n = 1378, aged 61–81 years, data on several CHD and metabolic risk factors were obtained to examine the relation of fasting glucose, insulin and C-peptide to 19-year CHD incidence. Age-adjusted incidence of CHD increased with increasing quintiles of glucose, insulin and C-peptide. Age-adjusted CHD rates in the glucose quintiles were 11.9, 11.6, 14.4, 18.1 and 24.1 per 1000 person-years (trend p < 0.001. In individual Cox models (lowest quintiles of glucose, insulin and C-peptide as reference the relative risks (95% confidence interval of CHD incidence for the glucose quintiles adjusting for age, smoking, hypertension, cholesterol, physical activity, and body mass index, were 0.9 (0.6–1.4, 1.2 (0.8–1.8, 1.4 (0.9–2.2, and 1.7 (1.1–2.6, respectively (trend p = 0.004. Insulin and C-peptide were not significantly associated with CHD on multivariate analysis. Fasting glucose remained the only significant predictor of increased CHD risk (p = 0.003 in a model combining all 3 metabolic variables. In this cohort, only fasting glucose independently predicts long-term incidence of CHD. Age-adjusted insulin and C-peptide levels were associated with CHD incidence, but after adjustment for other risk factors, do not independently predict CHD.

  4. Solid phase separation technique for use in radioimmunoassays

    International Nuclear Information System (INIS)

    Tu, J.I.

    1979-01-01

    A radioimmunoassay procedure, and article of manufacture for carrying out that procedure, are disclosed herein. The solid phase separation technique utilized in the radioimmunoassay of this invention utilizes a test tube, the internal surface of which has been coated with two antibody layers

  5. Radioimmunoassay techniques and reproductive management of livestock in North Africa

    International Nuclear Information System (INIS)

    Lahlou-Kassi, A.; Lakhdissi, H.

    1984-01-01

    The report summarizes the principal applications of progesterone radioimmunoassay (P 4 -RIA) in Morocco for evaluating and improving fertility in cattle, sheep and camels. In cattle, P 4 -RIA of blood or milk helped to determine the time for onset of sexual functions after parturition and the incidence of silent oestrus. It is especially important to assess the first factor in semi-extensively managed herds, while the second factor occurs mainly in intensively managed herds. P 4 -RIA is an important tool in fertility improvement programmes involving induction and synchronization of oestrus and testing for early pregnancy. In sheep, P 4 -RIA helped to define the optimum age at first mating of ewe lambs and the optimum mating season of the year for adult ewes. In camels, analysis of the profile of plasma progesterone before and after mating suggests that P 4 -RIA could be used for early pregnancy testing. (author)

  6. Radioimmunoassay for prostatic acid phosphatase in human serum. Methodologic aspects

    International Nuclear Information System (INIS)

    Pradalier, N.; Canal, P.; Pujol, A.; Fregevu, Y.; Soula, G.

    1982-01-01

    We propose a double antibody radioimmunoassay for human prostatic acid phosphatase (PAP) in serum for diagnosis and management of prostatic adenocarcinoma under treatment. The antigen is purified from human prostatic fluid by a gel-filtration on Sephadex G 100 followed by affinity chromatography on Con A Sepharose. A specific antibody is raised in rabbits and purified by immunoadsorption with a female serum. The described technique offers both radioisotopic sensibility and immunologic specificity. Physiological values determined in the serum of 125 healthy males are below 2 ng/ml. No significative differences are observed with age. The proposed technique also shows significant differences between values evaluated for benign prostatic hyperplasia and prostatic adenocarcinoma [fr

  7. Radioimmunoassay of paralytic shellfish toxins in clams and mussels

    International Nuclear Information System (INIS)

    Yang, G.C.; Imagire, S.J.; Yasaei, P.; Ragelis, E.P.; Park, D.L.; Page, S.W.; Carlson, R.E.; Guire, P.E.

    1987-01-01

    Shellfish contaminated with paralytic shellfish poisons (PSP) compromise human health. The threat of this contamination results in enormous economic losses in the recreational and commercial exploitation of shellfish resources in the affected areas. Most states deal with the PSP problem either by prohibiting the collection of shellfish during certain time periods or by instituting monitoring programs. The only recognized method of analysis for PSP that is currently and routinely used in monitoring programs is the time-of-death mouse bioassay. Several attempts to develop simple and highly specific biochemical assays for the detection and quantitation of the PSP toxins have been reported. More recently, much improved immunoassays have been developed. To evaluate the validity and usefulness of the immunoassay for the determination of PSP toxins, the authors have used extracts of shellfish gathered from Maine and Connecticut to compare the results of the mouse bioassay and HPLC methods with the radioimmunoassay developed previously

  8. A selective and simplified radioimmunoassay of 25-hydroxyvitamin D3

    International Nuclear Information System (INIS)

    Hummer, L.; Nilas, L.; Tjellesen, L.; Christiansen, C.

    1984-01-01

    A simple, non-chromatographic and selective assay for determination of 250 HD 3 in serum is described. The serum sample is deproteinated with acetonitrile and the supernatant purified over a small prepacked cartridge, Sep-pak. In the eluate from the cartridge, 250 HD 3 is measured by radioimmunoassay. The selectivity of the assay for 250 HD 3 is improved by adding vitamin D 2 to the antiserum; the assay is thus capable of measuring 250 HD 3 in serum samples containing up to a ratio of 250 HD 2 /250 HD 3 equal to 150. The simplicity, speed and the small amount of sample needed (0.5 ml) make this method suitable for use in a routine clinical laboratory. Because of its selectivity for 250 HD 3 the assay is a necessary prerequisite in the further investigation of metabolic discrimination between vitamins D 2 and D 3 . (author)

  9. Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid

    International Nuclear Information System (INIS)

    Delaage, M.A.; Puizillout, J.J.

    1981-01-01

    Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid were developed. High titer antibodies, having a well-defined high specificity, have been raised by coupling the side-chain of both molecules to human serum albumin. Serotonin is first converted into N-hemisuccinate, and then treated like 5-HIAA, namely, conjugated with HSA for the immunogen. Synthesis of 125 I iodinated analogues was performed by coupling 5-HIAA or N-succinyl serotonin to glycyltyrosine, without any contact between both molecules and the oxidizing reagents. Chemical conversions of biological samples (by succinylation for 5-HT and amidation for 5-HIAA) were carried out. This critical step makes the antigen molecules resemble the immunogen more closely, thus allowing an appreciable gain in specificity and sensitivity. These assays allow the rapid determination of 5-HT and 5-HIAA in small amounts of tissue, blood, cerebral spinal fluid or perfusate without any purification, with a sensitivity threshold of 50 pg

  10. Radioimmunoassay for pregnancy-associated plasma protein A

    International Nuclear Information System (INIS)

    Sinosich, M.J.; Teisner, B.; Folkerson, J.; Saunders, D.M.; Grudzinskas, J.G.

    1982-01-01

    A specific and highly sensitive radioimmunoassay for determination of pregnancy-associated plasma protein A in human serum is described. The minimum detection limit for this protein was 2.9 μg/L. The within- and between-assay coefficients of variation were 4.0 and 4.5%, respectively. The circulating protein was detected within 32 days of conception in eight normal pregnancies and within 21 days in a twin pregnancy. Circulating concentrations in the mother at term were consistently higher (10-fold) than in matched amniotic fluid; none was detected in the umbilical circulation. This protein was also detected in the circulation of patients with hydatidiform mole. This assay will permit investigations into the clinical evaluation of measurements of the protein during early pregnancy and trophoblastic disease

  11. Performance of various mathematical methods for calculation of radioimmunoassay results

    International Nuclear Information System (INIS)

    Sandel, P.; Vogt, W.

    1977-01-01

    Interpolation and regression methods are available for computer aided determination of radioimmunological end results. We compared the performance of eight algorithms (weighted and unweighted linear logit-log regression, quadratic logit-log regression, Rodbards logistic model in the weighted and unweighted form, smoothing spline interpolation with a large and small smoothing factor and polygonal interpolation) on the basis of three radioimmunoassays with different reference curve characteristics (digoxin, estriol, human chorionic somatomammotropin = HCS). Great store was set by the accuracy of the approximation at the intermediate points on the curve, ie. those points that lie midway between two standard concentrations. These concentrations were obtained by weighing and inserted as unknown samples. In the case of digoxin and estriol the polygonal interpolation provided the best results while the weighted logit-log regression proved superior in the case of HCS. (orig.) [de

  12. Radioimmunoassay of nortestosterone and related steroids

    International Nuclear Information System (INIS)

    Hampl, R.; Starka, L.; Picha, J.; Chundela, B.

    1979-01-01

    A radioimmunoassay of nortestosterone and related steroids, including its principal metabolites, is described and evaluated. Antisera against nortestosterone-17β-hemisuccinate- and nortestosterone-3-carboxymethyloxime-bovine serum albumin were raised in goats. By using a mixture of such antisera with different selectivity, the cross-reactions of several naturally occuring steroids can be reduced. The method can be applied for the detection of nortestosterone in both unprocessed or hydrolyzed urine extracts and also in plasma. It has been used as a screening test for anabolics in doping control. (orig.) [de

  13. Radioimmunoassay for thyroid-stimulating hormone (TSH)

    International Nuclear Information System (INIS)

    Blakemore, J.I.; Lewin, N.; Burgett, M.W.

    1978-01-01

    This invention provides a method for the radioimmunoassay of thyroid-stimulating hormone which utilizes a rapid and convenient version of a double antibody procedure. Highly purified second antibody is bound, by means of covalent bonds, to hydrolyzed polyacrylamide particles to produce a two-phase system. The solid phase comprises immobilized second antibody bound to the reaction product of labeled and unlabeled thyroid-stimulating hormone with the first antibody (first antibody-antigen complex) and the liquid phase comprises free (unbound) labeled and unlabeled thyroid-stimulating hormone. The two phases are separated and the radioactivity of either phase is measured

  14. Radioimmunoassay. A revolution in the analytic procedure

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, H; Eckert, H G [Farbwerke Hoechst A.G., Frankfurt am Main (Germany, F.R.). Radiochemisches Lab.

    1978-04-01

    Radioimmunoassay is an analytic method which combines the sensitivity of radioactive measurement and the specificity of the antigen-antibody reaction Substances down to a concentration of some picograms per ml serum (or biological material) can be measured in the presence of a millionfold excess of otherwise interfering substances. The method is easy to carry out (test tube chemistry). The main field of application at the moment is in endocrinology; further possibilities of application are in pharmaceutical research, environmental protection, forensic medicine, and for general analytic purposes. Radioactive sources are used only in vitro in the nanocurie range, i.e. radiation exposure is negligible.

  15. Transfer of estradiol to human milk. [Radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, S.; Nygren, K.G.; Johansson, E.D.B.

    1978-11-15

    A radioimmunoassay for the measurement of estradiol in human milk is evaluated. The detection limit was found to be 25 pg of estradiol per milliliter of milk. In milk samples collected from four lactating women during three to four months and from one pregnant and lactating woman, the concentration of estradiol was found to be below the detection limit of the assay. When six lactating women were given vaginal suppositories containing 50 or 100 mg of estradiol, it was possible to estimate the estradiol concentration in milk. A ratio of transfer of estradiol from plasma to milk during physiologic conditions is calculated to be less than 100 : 10.

  16. Radioimmunoassay in the diagnosis of fascioliasis

    Energy Technology Data Exchange (ETDEWEB)

    Tomanek, J; Willomitzer, J; Chroustova, E [Veterinary Research Inst., Brno (Czechoslovakia)

    1978-06-30

    The objective of the study was to develop a sensitive and specific radioimmunoassay (RIA) method for the diagnosis of F. hepatica infection that would be convenient to use in examining large numbers of samples. The main problem was the preparation of a suitable antigen or specific fraction, since the crude extract of adult Fasciola hepatica is a heterogeneous mixture of somatic, metabolic and host substances with possible nonspecific antigenic properties. The antigen was a protein fraction separated from crude extract of adult F. hepatica by gel filtration and labelled with /sup 125/iodine.

  17. Solid phase double-antibody radioimmunoassay procedure

    International Nuclear Information System (INIS)

    Niswender, G.D.

    1977-01-01

    The present invention is concerned with the radioimmunoassay (RIA) procedure for assaying body fluid content of an antigenic substance which may either be an antigen itself or a hapten capable of being converted, such as by means of reaction with a protein, to an antigenic material. The present invention is concerned with a novel and improved modification of a double-antibody RIA technique in which there is a first antibody that is specific to the antigenic substance suspected to be present in a body fluid from which the assay is intended. The second antibody, however, is not specific to the antigenic substance or analyte, but is an antibody against the first antibody

  18. Radioimmunoassay procedure using a stabilized complex

    International Nuclear Information System (INIS)

    Sultanian, I.V.; Irani, J.H.

    1978-01-01

    An improved radioimmunoassay procedure involves the use of a stabilized complex of labelled antigen and antibody which has an extended shelf life as compared to the same complex absent the stabilizers. Since the time needed to incubate the mixture of labelled antigen and antibody is eliminated, the time for completing the assay is considerably shortened and simplified. The components for carrying out the procedure are packaged in a kit basically including standard antigen for generation of a standard curve, a stabilized labelled antigen-antibody complex and reference serum, if used. A plurality of stabilizers are used in the complex to provide a shelf life of six weeks or more. 10 claims

  19. Radioimmunoassay in the diagnosis of fascioliasis

    International Nuclear Information System (INIS)

    Tomanek, J.; Willomitzer, J.; Chroustova, E.

    1978-01-01

    The objective of the study was to develop a sensitive and specific radioimmunoassay (RIA) method for the diagnosis of F. hepatica infection that would be convenient to use in examining large numbers of samples. The main problem was the preparation of a suitable antigen or specific fraction, since the crude extract of adult Fasciola hepatica is a heterogeneous mixture of somatic, metabolic and host substances with possible nonspecific antigenic properties. The antigen was a protein fraction separated from crude extract of adult F. hepatica by gel filtration and labelled with 125 iodine. (T.I.)

  20. Radioimmunoassay of sodium cromoglycate in human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K; Gardner, J J; Lockley, W J.S.; Preston, J R; Wilkinson, D J [Fisons plc, Loughborough (UK). Pharmaceutical Div.

    1983-01-01

    A sensitive radioimmunoassay method for sodium cromoglycate in human plasma is described. The lowest quantifiable concentration of sodium cromoglycate is 0.93 nmol/l when 0.1 ml plasma samples are analysed. The range of the method is limited; both 0.01 and 0.1 ml volumes of plasma must be analysed to encompass the concentration range 0.93-139 nmol/l which may be encountered in plasma samples from patients and human volunteers. The method is specific for sodium cromoglycate as indicated by a low cross-reactivity of the anti-cromoglycate antiserum with a number of drugs.

  1. HLA-DR typing by radioimmunoassay

    International Nuclear Information System (INIS)

    Tosi, R.; Tanigaki, N.; Centis, D.; Rossi, P.L.; Alfano, G.; Ferrara, G.B.; Pressman, D.

    1980-01-01

    A radioimmunoassay procedure is described by which peripheral blood lymphocytes can be typed for HLA-DR specificities. The major advantages of this method are the following: simple and reproducible procedure, no need for B lymphocyte separation, no need for optimal viability, and no need for preabsorption of antisera with platelets. This method will find an application in the genetic and biochemical analysis of the HLA complex, and in the clinical tests of Ia antigens for diagnostic or prognostic purposes and in retrospective transplant studies

  2. Development of a radioimmunoassay for papain

    International Nuclear Information System (INIS)

    Rauch, P.; Fukal, L.; Marek, M.; Strejcek, F.; Kas, J.

    1984-01-01

    Various well-tried radioimmunoassay (RIA) techniques were compared for the quantitation of papain. The evaluation of individual assays was performed by logit-log analysis. The most compatible analytical steps were combined in order to obtain the optimal analytical conditions of the assay. The preferred RIA involves papain labelling with lactoperoxidase, a double antibody method as the separation step and a 24 h incubation period at 2 0 C. It permits the detection of 16 ng of papain per tube. In contrast, a method using immobilized antibody was satisfactory for rapid quantitation of papain with quite acceptable accuracy. (Auth.)

  3. A solid phase radioimmunoassay for free triiodothyronine in serum: assay development and validation

    International Nuclear Information System (INIS)

    Liu Fangyan; Zhou Meiying; Yin Linxiang; Yang Jianzhong; Hua Chenglin

    1999-01-01

    A solid phase radioimmunoassay for free triiodothyronine in serum was developed based on double-antibody coated tubes. The method was turned out to be reliable with good reproducibility, higher sensitivity and easy performance. The measurable range of FT 3 in serum was 1.2 to 38 pmol/L. The mean coefficients of variation within and between assays were 1.79%∼3.18% and 4.72%∼9.31%, respectively. The FT 3 concentrations in euthyroid serum as determined by this method were 2.8 to 7.8 pmol/L. The FT 3 values determined by this new method correlated well with those measured by a commercial radioimmunoassay (r = 0.853)

  4. Urinary C-peptide: a useful tool for evaluating the endogenous insulin reserve in cohort and longitudinal studies of diabetes in childhood.

    Science.gov (United States)

    de Beaufort, C E; den Boer, N C; Bruining, G J; Eilers, G A; van Strik, R; Weterings, T

    1988-09-01

    Increasing research into the remission phase of type I diabetes mellitus stresses the importance of a non-traumatic and reliable method for the evaluation of endogenous insulin production. We compared 24-h urinary C-peptide excretion (UCE) with plasma C-peptide values before and after stimulation with 1 mg glucagon in 24 type I diabetic children. Fasting plasma C-peptide values and stimulated plasma C-peptide values showed a linear correlation with 24 h UCE. Mean plasma C-peptide levels correlated inversely with the exogenous insulin dose. A slightly better correlation was found between the exogenous insulin dose and 24 h UCE. Control data of 24 h UCE were obtained from healthy siblings. A linear correlation with age was found up to 10 years of age above which UCE values seem to reach a plateau. This effect of age, as well as the frequency of sampling was taken into account in the derivation of 95% reference intervals for UCE. The measurement of 24 h UCE appears to be a useful parameter to assess endogenous insulin production in diabetic children, provided that age is taken into account.

  5. Short-term glucagon stimulation test of C-peptide effect on glucose utilization in patients with type 1 diabetes mellitus.

    Science.gov (United States)

    Mojto, Viliam; Rausova, Zuzana; Chrenova, Jana; Dedik, Ladislav

    2015-12-01

    This work aimed to evaluate the use of a four-point glucagon stimulation test of C-peptide effect on glucose utilization in type 1 diabetic patients using a new mathematical model. A group of 32 type 1 diabetic patients and a group of 10 healthy control subjects underwent a four-point glucagon stimulation test with blood sampling at 0, 6, 15 and 30 min after 1 mg glucagon bolus intravenous administration. Pharmacokinetic and pharmacokinetic/pharmacodynamic models of C-peptide effect on glucose utilization versus area under curve (AUC) were used. A two-sample t test and ANOVA with Bonferroni correction were used to test the significance of differences between parameters. A significant difference between control and patient groups regarding the coefficient of whole-body glucose utilization and AUC C-peptide/AUC glucose ratio (p ≪ 0.001 and p = 0.002, respectively) was observed. The high correlation (r = 0.97) between modeled coefficient of whole-body glucose utilization and numerically calculated AUC C-peptide/AUC glucose ratio related to entire cohort indicated the stability of used method. The short-term four-point glucagon stimulation test allows the numerically calculated AUC C-peptide/AUC glucose ratio and/or the coefficient of whole-body glucose utilization calculated from model to be used to diagnostically identify type 1 diabetic patients.

  6. Radioimmunoassays in prenatal genetic diagnosis

    International Nuclear Information System (INIS)

    Santavy, J.; Janouskova, M.; Fingerova, H.; Krikal, Z.

    1981-01-01

    Prenatal medicine strives to reveal hereditary disorders and congenital malformations before delivery. The application of RIA significantly widened the spectrum of available diagnostic possibilities. We first focused our attention on determining alpha-1-fetoprotein in the amniotic fluid and the serum. We used the results of 33 examinations of the amniotic fluid and 100 samples of the blood serum to compile a graph of physiological values during pregnancy. The graph is used in assessing clinical samples in suspect congenital disorders of neural tube closure and other malformations. In the last two years we have tested testosterone determination in the amniotic fluid to ascertain prenatally the fetal sex in early pregnancy. The results were satisfactory and agreed in 70.6%. (author)

  7. New Solid Phases for Estimation of Hormones by Radioimmunoassay Technique

    International Nuclear Information System (INIS)

    Sheha, R.R.; Ayoub, H.S.M.; Shafik, M.

    2013-01-01

    The efforts in this study were initiated to develop and validate new solid phases for estimation of hormones by radioimmunoassay (RIA). The study argued the successful application of different hydroxy apatites (HAP) as new solid phases for estimation of Alpha fetoprotein (AFP), Thyroid Stimulating hormone (TSH) and Luteinizing hormone (LH) in human serum. Hydroxy apatites have different alkali earth elements were successfully prepared by a well-controlled co-precipitation method with stoichiometric ratio value 1.67. The synthesized barium and calcium hydroxy apatites were characterized using XRD and Ftir and data clarified the preparation of pure structures of both BaHAP and CaHAP with no evidence on presence of other additional phases. The prepared solid phases were applied in various radioimmunoassay systems for separation of bound and free antigens of AFP, TSH and LH hormones. The preparation of radiolabeled tracer for these antigens was carried out using chloramine-T as oxidizing agent. The influence of different parameters on the activation and coupling of the used apatite particles with the polyclonal antibodies was systematically investigated and the optimum conditions were determined. The assay was reproducible, specific and sensitive enough for regular estimation of the studied hormones. The intra-and inter-assay variation were satisfactory and also the recovery and dilution tests indicated an accurate calibration. The reliability of these apatite particles had been validated by comparing the results that obtained by using commercial kits. The results finally authenticates that hydroxyapatite particles would have a great potential to address the emerging challenge of accurate quantitation in laboratory medical application

  8. Radioimmunoassay for luteinizing hormone releasing hormone in plasma

    International Nuclear Information System (INIS)

    Saito, Shiro; Musa, Kimitaka; Oshima, Ichiyo; Yamamoto, Suzuyo; Funato, Toyohiko

    1975-01-01

    A sensitive and specific double antibody radioimmunoassay has been developed capable of measuring LH-RH in extracted human plasma. Thyrotropin releasing hormone, lysine vasopressin and most of LH-RH analogues did not appear to affect the assay. Hypothalamic extract and some of the LH-RH analogues produced displacement curves which were parallel to the curve obtained with the synthetic LH-RH. Sensitivity of the radioimmunoassay was about 3 pg per assay tube. The coefficient of variation of intraassays was 6.4%, while that of interassays was 9.6%. Exogenous LH-RH could be quantitatively extracted by acidic ethanol when varying amounts of synthetic LH-RH were added to the plasma. Immunoreactivity of LH-RH was preserved in plasma for 2 hrs in the cold but was gradually reduced thereafter. The plasma levels of LH-RH were 20 pg/ml or less in normal adults and not detectable in children. Aged males over 60 yr and postmenopausal women showed a tendency to have higher levels of plasma LH-RH. The plasma LH-RH level was significantly higher in midcycle than in the follicular or luteal stages. The disappearance rate of LH-RH from the circulation after intravenous injection could be represented as half-times of 4-6 min. Between 0.2-0.4% of the injected dose was excreted into urine within 1 hr. These results indicate that the determination of LH-RH might be a useful tool for elucidating hypothalamic-pituitary-gonad interactions. (auth.)

  9. Development of a radioimmunoassay for circulating levels of gonadotropin releasing hormone

    International Nuclear Information System (INIS)

    Moodbidri, S.B.; Joshi, L.R.; Sheth, A.R.; Rao, S.S.

    1976-01-01

    A specific and sensitive radioimmunoassay system has been developed for measuring gonadotropin releasing hormone (GnRH) in unextracted human serum. Circulating levels of GnRH, LH and FSH were determined in 37 serum samples obtained from twenty normal healthy women on different days of the menstrual cycle. GnRH and LH but not FSH exhibited similar patterns during the menstrual cycle. 125 I-labelled GnRH was used in the RIA system. (author)

  10. Radioimmunoassay detection of levels of triiodothyronine and thyroxine in Mangalarga Marchador equine

    International Nuclear Information System (INIS)

    Viana, F.A.B.; Pessoa, J.M.; Biondini, J.

    1991-01-01

    Serum levels of triiodothyronine (T 3 ) and thyroxine (T 4 ) were determined in equine of Mangalarga Marchador breed through radioimmunoassay. Forty-two animals (17 males and 25 females), with age ranging from two to eighteen years, were utilized. The values recorded for males and females were, respectively: 101.68 ± 23.44 and 71.14 ± 18.82 ng/d l of T 3 (P 4 (P<0.05). (author). 10 refs, 1 tab

  11. Radioimmunoassay of haloperidol in human serum: correlation of serum haloperidol with serum prolactin

    International Nuclear Information System (INIS)

    Poland, R.E.; Rubin, R.T.

    1981-01-01

    A radioimmunoassay (RIA) for measurement of serum haloperidol is described. Compared to gaschromatography (GC), RIA vaues average 40% higher. However, a simple organic extraction of serum yields statistically equivalent RIA and GC haloperidol determinations. For both men and women combined, there was a positive correlation between dose (mg/kg/day) and steady-state serum haloperidol level (r = +0.86) and between steady-state serum haloperidol and serum prolactin (PRL) concentration

  12. Clarification of the technic of intrinsic factor radioimmunoassay for the cat and the rat

    International Nuclear Information System (INIS)

    Perrin, M.O.; Nicolas, J.P.; Dubrasquet, M.

    1983-01-01

    Cats and rats secrete very small quantities of gastric juice (GJ). In order to measure the Intrinsic Factor (IF) in GJ of animals certain modifications are necessary. It is very important to select with great care pernicious anemia sera which will be used to cross react with the animals' IF to determine their IF level by radioimmunoassay. The technic described here enables the dosage of low quantities of IF with a 7 per cent coefficient of variation [fr

  13. Immunoradiometric assay for prolactin in serum and tissue; Comparison with radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Ohnami, Shumpei; Nakata, Hajime; Eto, Sumiya (University of Occupational and Environmental Health Hospital, Kitakyushu, Fukuoka (Japan))

    1990-09-01

    Prolactin (PRL) concentrations in sera and tumors of patients with various pituitary tumors were measured by both immunoradiometric assay (IRMA) and radioimmunoassay (RIA). PRL concentrations in sera and tumor tissues measured by IRMA were well correlated with those measured by RIA. PRL concentrations in sera reflected those of tumors removed. This IRMA is a simple and useful method for PRL determination in serum and tissue. (author).

  14. Interferences in radioimmunoassay of aflatoxins in food and fodder samples of plant origin

    International Nuclear Information System (INIS)

    Rauch, P.; Fukal, L.; Brezina, P.; Kas, J.

    1988-01-01

    Cross-reactions and resulting nonspecific binding of substances with structures resembling aflatoxins (derivatives of coumarin, and cinnamonic and benzoic acids, etc.) were investigated. The concentrations of these substances causing erroneously high or false positive values in radioimmunoassay were determined. One μg aflatoxin B 1 /kg sample may be simulated by the occurrence of 5 g coumarin, 10 g caffeic acid, 16 g chlorogenic acid, or 15 g vanillin/kg fodder or food sample

  15. Radioimmunoassay of bleomycin in plasma and urine

    International Nuclear Information System (INIS)

    Teale, J.D.; Clough, J.M.; Marks, V.

    1977-01-01

    Antibodies to bleomycin were raised by immunization of sheep and rabbits with bleomycin-albumin conjugates. The combination of a high-titre, high-avidity sheep antiserum and iodinated bleomycin produced a radioimmunoassay sensitive to 8 ng of bleomycin per ml of plasma or urine. Untreated specimens (100 μl) of plasma or urine could be added directly to the assay tubes. The anti-serum was specific for bleomycin and showed no cross-reaction with other anti-cancer agents used in combination chemotherapy. Over a concentration range of 20 to 100 ng/ml. recovery of bleomycin from plasma was 110% and from urine, 93%. Repeated assay of plasma samples showed a decrease in bleomycin levels unless the samples were kept at 4 0 C or below. Assay of bleomycin levels in plasma and urine from patients under treatment with bleomycin showed similarities with results reported using a microbiological assay. The radioimmunoassay offers a more reliable, rapid and sensitive method for the measurement of bleomycin. (author)

  16. Improvement of C peptide zero BMI 24-34 diabetic patients after tailored one anastomosis gastric bypass (BAGUA).

    Science.gov (United States)

    Garciacaballero, M; Martínez-Moreno, J M; Toval, J A; Miralles, F; Mínguez, A; Osorio, D; Mata, J M; Reyes-Ortiz, A

    2013-03-01

    Although bariatric surgery proved to be a very effective method in the treatment of patients in whose pancreas still produce insulin (type 2 diabetes), the accompanied metabolic syndrome and their diabetes complications, there is no information on the effect of this type of surgery in BMI24-34 patients when pancreas do not produce insulin at all (type 1, LADA and long term evolution type 2 diabetes among others). We report preliminary data of a serie of 11 patients all with a C-peptide values below 0.0 ng/ml. They were followed for 6 to 60 months (mean 19 months) after surgery. We studied the changes in glycemic control, evolution of the metabolic syndrome and diabetes complications after one anastomosis gastric bypass (BAGUA). All values relative to glycemic control were improved HbA1c (from 8.9 ± 0.6 to 6.7 ± 0.2%), FPG (Fasting Plasma Glucose) [from 222.36 ± 16.87 to 94 ± 5 (mg/dl)] as well as the daily insulin requirement of rapid (from 40.6 ± 12.8 to 0 (U/d) and long-lasting insulin (from 41.27 ± 7.3 U/day to 15.2 ± 3.3 U/day). It resolved 100% of the metabolic syndrome diseases as well as severe hypoglycaemia episodes present before surgery and improved some serious complications from diabetes like retinopathy, nephropathy, neuropathy, peripheral vasculopathy and cardiopathy. Tailored one anastomosis gastric bypass in BMI 24-34 C peptide zero diabetic patients eliminated the use of rapid insulin, reduced to only one injection per day long-lasting insulin and improved the glycemic control. After surgery disappear metabolic syndrome and severe hypoglycaemia episodes and improves significantly retinopathy, neuropathy, nephropathy, peripheral vasculopathy and cardiopathy. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  17. Skim Milk, Whey, and Casein Increase Body Weight and Whey and Casein Increase the Plasma C-Peptide Concentration in Overweight Adolescents12

    DEFF Research Database (Denmark)

    Arnberg, Karina; Mølgaard, Christian; Michaelsen, Kim Fleischer

    2012-01-01

    insulin, and insulin secretion estimated as the plasma C-peptide concentration in overweight adolescents. Overweight adolescents (n = 203) aged 12–15 y with a BMI of 25.4 ± 2.3 kg/m2 (mean ± SD) were randomized to 1 L/d of skim milk, whey, casein, or water for 12 wk. All milk drinks contained 35 g protein....... Outcomes were BMI-for-age Z-scores (BAZs), waist circumference, plasma insulin, homeostatic model assessment, and plasma C-peptide. We found no change in BAZ in the pretest control and water groups, whereas it was greater at 12 wk in the skim milk, whey, and casein groups compared with baseline...... and with the water and pretest control groups. The plasma C-peptide concentration increased from baseline to wk 12 in the whey and casein groups and increments were greater than in the pretest control (P

  18. Study of neuropeptide distribution in the central nervous system by the combined use of radioimmunoassay with the neuroatomic punch technique

    International Nuclear Information System (INIS)

    Valenca, M.M.; Negro Vilar, A.

    1991-01-01

    In order to demonstrate an experimental method to study neuropeptide distribution in the central nervous system, the content of beta-endorphin present in several brain regions was determined by the combined use of radioimmunoassay with the neuroanatomic punch technique described by Palkovits. (author)

  19. Radioimmunoassay of diagoxin with the aid of the solid phase - microtitre plating technique

    International Nuclear Information System (INIS)

    Scheidt, C.

    1982-01-01

    Preliminary results are reported here on the development of a digoxin-radioimmunoassay with an anti-digoxin antibody (goat) in a solid phase technique (mictrotitre plate). The advantages compared to conventional RIAs are: Cross reactions towards digoxin is minimal, both in vitro and in vivo. The calibraton range extends from 0.25 to 8 ng/ml. The radioactive load could be reduced significantly by use of smaller amounts of tracer (0.004 μCi/single determination) and by reduction of waste volume (solid), waste weight (solid) and liquid waste. The DIGOXIN RIA BIOTEST MTP is, in addition, the only digoxin radioimmunoassay where radioactive waste is produced in a sealed form. The test is a simple one and can be carried out without the need for complicated apparatus and techniques. (orig./MG) [de

  20. Steroid radioimmunoassay: contribution of standards to blank values, ch. 4

    International Nuclear Information System (INIS)

    Froelich, M.; Termorshuizen, W.; Kenter, E.; Molenaar, A.J.

    1977-01-01

    The sensitivity of the radioimmunoassay of steroids is considerably reduced by high blank values which may be derived in part from co-chromatographed standards. Blank levels approach the detection limit of the radioimmunoassay of aldosterone, testosterone and androstenedione when 10,000 dpm (30-35 pg) labelled steroids are used as reference standard. When 20 μg aldosterone, testosterone, or androstenedione is used as standard, blank levels of up to 12,800 pg were measured in the radioimmunoassay. Application of the standards on a separate strip does not improve the results. From the experiments it appeared that contamination took place by transport by the solvent

  1. A competitive-inhibiton radioimmunoassay for influenza virus envelope antigens

    International Nuclear Information System (INIS)

    Russ, G.; Styk, B.; Vareckova, E.; Polakova, K.

    1976-01-01

    A double-antibody competitive-inhibition radioimmunoassay for influenza virus envelope antigens is described. A viral antigen preparation from influenza A virus recombinant MRC11 [antigenically identical to A/Port Chalmers/1/73 (H3N2)] consisting of haemagglutinin and neuraminidase was labelled with radioiodine. Rabbit antisera were allowed to react with the labelled antigen and the resultant antigen-antibody complexes were precipitated with the appropriate antiglobulin. The competitive-inhibition radioimmunoassay very sensitively elucidated differences even among closely related influenza virus strains. Attempts have been made to eliminate neuraminidase from radioimmunoprecipitation to obtain a competitive-inhibition radioimmunoassay system for haemagglutinin alone. (author)

  2. Radioiodinated derivatives for steroid radioimmunoassay. Application to the radioimmunoassay of cortisol

    International Nuclear Information System (INIS)

    Gomez-Sanchez, C.; Milewich, L.; Holland, O.B.

    1977-01-01

    Gamma-emitting steroid tracers for use in the radioimmunoassay of steroids have a number of advantages over the more common tritiated tracers. The steroid derivatives aldosterone-3-(p-hydroxybenzoyl) hydrazone, aldosterone-3-(p-hydroxyphenylpropionyl)hydrazone, deoxycorticosterone-3-(p-hydroxyphenylpropionyl)hydrazone, and cortisol-3-(p-hydroxyphenylpropionyl)hydrazone were synthesized by a one-step procedure and iodinated ([ 125 I]). To illustrate the usefulness of these derivatives, we describe the details of a cortisol radioimmunoassay. The use of the radioiodinated tracer appeared to increase the specificity of the antigen-antibody reaction when compared with [ 3 H]cortisol. The methodology involved in the preparation of the steroid derivatives described above can be extended to other 3-oxo-4-ene-containing steroids, with the advantages of economy, simplicity, and versatility

  3. Meta-genome-wide association studies identify a locus on chromosome 1 and multiple variants in the MHC region for serum C-peptide in type 1 diabetes.

    Science.gov (United States)

    Roshandel, Delnaz; Gubitosi-Klug, Rose; Bull, Shelley B; Canty, Angelo J; Pezzolesi, Marcus G; King, George L; Keenan, Hillary A; Snell-Bergeon, Janet K; Maahs, David M; Klein, Ronald; Klein, Barbara E K; Orchard, Trevor J; Costacou, Tina; Weedon, Michael N; Oram, Richard A; Paterson, Andrew D

    2018-05-01

    The aim of this study was to identify genetic variants associated with beta cell function in type 1 diabetes, as measured by serum C-peptide levels, through meta-genome-wide association studies (meta-GWAS). We performed a meta-GWAS to combine the results from five studies in type 1 diabetes with cross-sectionally measured stimulated, fasting or random C-peptide levels, including 3479 European participants. The p values across studies were combined, taking into account sample size and direction of effect. We also performed separate meta-GWAS for stimulated (n = 1303), fasting (n = 2019) and random (n = 1497) C-peptide levels. In the meta-GWAS for stimulated/fasting/random C-peptide levels, a SNP on chromosome 1, rs559047 (Chr1:238753916, T>A, minor allele frequency [MAF] 0.24-0.26), was associated with C-peptide (p = 4.13 × 10 -8 ), meeting the genome-wide significance threshold (p C>T, MAF 0.07-0.10, p = 8.43 × 10 -8 ). In the stimulated C-peptide meta-GWAS, rs61211515 (Chr6:30100975, T/-, MAF 0.17-0.19) in the MHC region was associated with stimulated C-peptide (β [SE] = - 0.39 [0.07], p = 9.72 × 10 -8 ). rs61211515 was also associated with the rate of stimulated C-peptide decline over time in a subset of individuals (n = 258) with annual repeated measures for up to 6 years (p = 0.02). In the meta-GWAS of random C-peptide, another MHC region, SNP rs3135002 (Chr6:32668439, C>A, MAF 0.02-0.06), was associated with C-peptide (p = 3.49 × 10 -8 ). Conditional analyses suggested that the three identified variants in the MHC region were independent of each other. rs9260151 and rs3135002 have been associated with type 1 diabetes, whereas rs559047 and rs61211515 have not been associated with a risk of developing type 1 diabetes. We identified a locus on chromosome 1 and multiple variants in the MHC region, at least some of which were distinct from type 1 diabetes risk loci, that were associated with C-peptide

  4. Report on the national seminar on radioimmunoassays

    International Nuclear Information System (INIS)

    1979-01-01

    Deliberations of the National Seminar on Radioimmunoassays (RIA) held at Bombay during 16-20 January 1978 are reported. Various aspects of the application of RIA techniques in India were discussed in the seminar. They included the basic requirements of RIA in India, the state-of-the-art of RIA in India, radiation protection in RIA, quality control of RIA, usefulness and limitations of RIA in clinical diagnosis and use of RIA in tropical infectious diseases. Difficulties encountered in the practice of RIA techniques in India were found to be mainly related to availability of 125 I, RIA kits, antisera and hormones. The need for establishing a centralised assay service for RIA was examined and it was concluded that such a step would be premature in the present situation. Recommendations made and guidelines spelt out deal with resources for RIA, research, referral assay service, training and information exchange and dissemination. (M.G.B.)

  5. A radioimmunoassay for neurotensin in human plasma

    International Nuclear Information System (INIS)

    Blackburn, A.M.; Bloom, S.R.

    1979-01-01

    A radioimmunoassay was developed for detecting the neurotensin peptide in human plasma. The plasma was specific for neurotensin as no cross-reaction was found with any of the other gut hormones tested. Changes of 5 pmol/l could be detected with 95% confidence. Neurotensin was unstable in both blood and plasma but considerable protection was afforded by addition of aprotinin, rapid separation of plasma and immediate deep freezing. Neurotensin-like immunoreactivity was detected in human plasma in both a small and large molecular form. The mean fasting level of plasma neurotensin-like immunoreactivity in 36 healthy volunteers was 29 +- 3 pmol/l. A significant increment of 27 +- 8 pmol/l plasma neurotensin immunoreactivity was detected after a large meal in nine healthy men. In view of the present results in man and also of neurotensin's potent pharmacological actions in experimental animals, neurotensin appears to fulfil some of the criteria needed for a hormone. (UK)

  6. Sensitive radioimmunoassay for plasma arginine vasopressin

    International Nuclear Information System (INIS)

    Thibonnier, M.; Soto, M.E.; Corvol, P.; Milliez, P.; Marchetti, J.; Menard, J.

    1980-01-01

    Using an ion exchange resin, a sensitive radioimmunoassay for plasma arginine vasopressin (AVP) was developed. This assay was characterized by the absence of blank values, an excellent recovery rate, great sensitivity (0.1 pg of AVP was significantly detected) and reproducibility. In 8 normal men, plasma AVP after overnight dehydration was 1.57+-0.17 pg/ml, and dropped to 0.58+-0.11 pg/ml after 20 ml/kg oral water loading. Significant correlations between plasma AVP levels and plasma or urinary osmolality confirm the validity of this assay. In complete pituitary diabetes insipidus (n=4) plasma AVP was undetectable whereas it was frankly increased in Schwartz-Bartter syndrome (3 to 33 pg/ml, n=8) [fr

  7. Standardised multicentre procedure for plasma gonadotrophin radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, K M; Hayes, M; Jeffcoate, S L [Chelsea Hospital for Women, London (UK)

    1982-09-01

    A radioimmunoassay method for the assay of luteinising hormone (LH) and follicle-stimulating hormone (FSH) in serum/plasma has been designed for use in laboratories of varying expertise in the United Kingdom. The major sources of experimental error leading to poor within-laboratory performance and between-laboratory comparability were identified: quality of tracer, use of calibration standards, and separation procedure. A simple rugged kit was designed which was extensively tested first in our laboratory and then in a small multi-centre field trial before being made available. It is now used routinely by 26 health service and research laboratories. The working range of the assays is 1-50 IU/l (LH) and 0.3-16 IU/l (FSH). The between-batch reproducibility was 5-11% (CV) over the dose range 4.8-18 IU/l (LH) and 1.6-15 IU/l (FSH).

  8. Radioimmunoassay of 17-beta - estradiol in plasma

    International Nuclear Information System (INIS)

    Kyian, T.S.; Wajchenberg, B.L.

    1980-01-01

    A radioimmunoassay technique for the measurement of plasma E 2 was standardized utilizing a highly specific antisera against E 2 [-6(-0-carboximetil)-oxime] BSA without the need of previous chromatographic purification. The anti-E 2 serum was highly specificic, showing high affinity with affinity constants:K 1 =1.62 x 10 12 M -1 and K 2 =2.94x10 11 M -1 , calculated by Scatchard plot. The standard-curve sensitivity was 2 picograms. The method was specific and accurate, showing an intra-assay precision with a mean C.V. of 2.9%, with the inter-assay evaluation showing a mean C.V. of 5.0%. This method was employed to evaluate E 2 secretion during the menstrual cycle in 6 normal female. (Author) [pt

  9. Radioimmunoassay in basic and clinical pharmacology

    International Nuclear Information System (INIS)

    Patrono, C.; Peskar, B.A.

    1987-01-01

    The subject of the book is the development, validation and application of radioimmunoassay (RIA) techniques for the measurement of a variety of substances in animal and human body fluids. The book discusses methodological and conceptual issues related to the main classes of mediators of drug action and to drugs themselves, as assayed by this particular analytical technique. A number of introductory chapters provide basic information concerning production and characterization of antibodies, labeling techniques, statistical aspects and validation criteria, insight into problems related to the development and validation of RIA for the newly discovered mediator(s). In the following chapters, the emphasis is placed on the technical details relevant to each class of compounds and on specific aspects of their applications to basic and/or clinical pharmacological studies. New developments in this area, such as monoclonal antibodies and non-radioactive labeling techniques, are also covered

  10. Beta-endorphin radioimmunoassay: specificity studies

    Energy Technology Data Exchange (ETDEWEB)

    Colas-Linhart, N.; Perdrisot, R.; Petiet, A.; Bok, B.

    1986-01-01

    This note describes the technical details of a cerebrospinal fluid (CSF) B-Endorphin (B-End) radioimmunoassay (RIA). We used an antiserum raised in rabbits against human B-End which cross-reacs 100% with B-Lipotrophin (B-Lph). Thus, filtration chromatography is used to separate both peptides. The assay is sensitive (limit detection=14 pmoles/l), reproducible (the intra and inter assay coefficients of variation are 5 and 6% respectively). Specificity studies are performed to verify the cross-reactions with other opioid peptides and the non specific reactions with the biological fluid (CSF). In order to evaluate the effects of iodine-containing contrast media on the RIA, additional standard curves were analyzed in the presence of varying concentrations of two contrast materials.

  11. Quantitation of secretory protein levels by radioimmunoassay

    International Nuclear Information System (INIS)

    Klein, J.L.; Dawson, J.R.

    1978-01-01

    A radioimmunoassay was designed for the detection of secretory protein, a component of secretory immunoglobulin A, in human serum. The assay uses free secretory protein isolated from human colostrum, and antisera raised in rabbits to be purified antigen. The mean level of secretory protein in the control group was 2.34+-0.41 μg/ml (mean+-S.E.M.). The level in cord blood was slightly lower (0.74+-0.26 μg/ml), while the level in patients with ovarian carcinoma was significantly increased (12.67+-1.43 μg/ml). Pregnant women have increasingly secretory protein levels with increasing length of gestation (5.86+-2.02, 11.55+-1.30 and 17.00+-1.16 μg/ml for the first, second and third trimesters, respectively. (Auth.)

  12. Radioimmunoassay for GRF and CRF in humans

    International Nuclear Information System (INIS)

    Stalla, G.K.; Losa, M.; Kaliebe, T.; Stalla, J.; Schopohl, J.; Muller, O.A.; Von Werder, K.

    1987-01-01

    In 1981 the structure of ovine CRF was established. One year later others isolated a 44 amino acid peptide with GH releasing activity from a pancreatic islet cell carcinoma of an acromegalic patient (hp GRF/sup 1-44/). In 1983 the gene of human CRF was cloned and the amino acid sequence of hCRF could be elucidated. It differs in 7 amino acids from oCRF. Many investigators demonstrated the biological activity of these peptides in vitro and in vivo. The aim of the authors study was to establish radioimmunoassays for GRF and hCRF with the synthetic derivates, measure endogenous GFR and CRF and circulating GRF- and CRF-levels after intravenous injection and calculate metabolic clearance rate and half-time of disappearance from serum for both releasing hormones

  13. Radioimmunoassay of human plasma protein C

    International Nuclear Information System (INIS)

    Wang Bocheng; Li Jinquan; Jing Jian; Zhang Manda

    1995-01-01

    A radioimmunoassay method for the measurement of human plasma protein C (PC) is established. PC was isolated and purified from human plasma. The antisera against PC was obtained by immunizing rabbits. Iodination of PC was carried out with chroramine-T. The sensitivity was 3.94% μg/L, and the assay covered 6.25∼1024 μg/L for PC. The intra-assay and inter-assay CV were 4.4% and 9.68% respectively, with a recovery rate of 104.28%. There was no cross reaction with factor II. The normal value was 3.84 +- 0.34 mg/L in 36 normal persons. Value of 1.03 +-0.41 mg/L was found in 16 patients with fulminating hepatitis complicated with coagulation disturbance. It is an effective approach for the diagnosis of hereditary or acquired PC deficiency and also for the study of thrombotic diseases

  14. Radioimmunoassay for medical diagnosis and research

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, R A; Vavrejn, B [International Atomic Energy Agency, Vienna (Austria). Div. of Life Sciences

    1982-12-01

    Health and disease in living systems depend on the dynamic interplay of thousands of biochemical substances occurring in living systems in concentrations ranging from parts per hundred to parts per billion or trillion. Radioimmunoassay (RIA) is a highly specific and sensitive technique for measuring the concentration of such biochemical substances. It represents one of the most dramatically expanding areas of medical diagnosis and research. Reviewed here is the recent progress on RIA, with emphasis on methodology and on its adaptation and application in developing countries. The number of biological substances (ligands) being assayed by RIA continues to expand. RIA is central to diagnosis, epidemiology and research. It has been successfully applied in the study of parasitic and infectious diseases. Introduction of RIA into developing countries, for which the Agency's help is sought and given, presents numerous problems: personnel, equipment, adaptability of techniques to local needs, and public support.

  15. Radioimmunoassay of urine oxytocin in man

    International Nuclear Information System (INIS)

    Zebidi, A.; Geelen, G.; Allevard, A.M.; Sempore, B.; Jarsaillon, E.; Meunier, C.; Gharib, C.

    1978-01-01

    A radioimmunoassay (RIA) for oxytocin (OT) in urine is described. 125 I-OT was prepared, and antibodies were raised in rabbits against OT coupled to bovine serumalbumine. This allowed us to set up a RIA for OT which limit of detection is 1.25 pg/tube (0.6 μU). The use of an extraction procedure using CG 50 Amberlite is essential. The recovery after extraction reaches 70.5 %. pH 5 is the optimum pH were urine samples must be stored. The superposition of the elution peak of endogenous OT on that of exogenous hormone is an argument in favour of the validity of such an extraction procedure. Daily urinary excretion of OT reaches 9.58 mU +- 3.48 in 18 healthy young men [fr

  16. Radioimmunoassay of cholecystokinin in tissue and plasma

    International Nuclear Information System (INIS)

    Jansen, J.B.M.J.

    1984-01-01

    The physiological and pathophysiological role of the pancreas hormone, the polypeptide 'cholecystokinin' (CCK) is not well-established yet. This is due to the lack of specific and reliable radioimmunoassays for CCK. The aim of this thesis is to develop such an assay meeting the requirements of high specificity and sensitivity. Several problems were faced, such as (1) the cross-reactivity of existing antibodies with the stomach hormone gastrin and (2) changes in immunoreactivity caused by the introduction of the labelling isotope 125 I and various labels (prepared according to the Bolton-Hunter method) into the polypeptide. The reliability of the assay for the measurement in human tissue and blood is extensively evaluated, inter alia, in patients with pancreas insufficiency (alcohol, cystic fibrosis) and with coeliac disease. (Auth.)

  17. Radioimmunoassay of progesterone in unextracted serum

    International Nuclear Information System (INIS)

    Haynes, S.P.; Corcoran, J.M.; Eastman, C.J.; Doy, F.A.

    1980-01-01

    A rapid, precise radioimmunoassay for progesterone in 25 μL of unextracted serum is described. Progesterone is released from its binding protein by adding an optimal amount of cortisol, which binds to the same protein (cortisol binding globulin) as progesterone. The amount of cortisol required does not cross react with the specific progesterone antibody used. This approach considerably shortens assay time and removes a tedious and imprecise stage in the conventional assay of serum progesterone. Results correlated well (r = 0.97) with a method involving organic solvent extraction of progesterone from serum. During the two years we have used this mehod in a busy diagnostic endocrine laboratory, the between-assay precision (CV) for low-, medium-, and high-concentration quality control sera was 12, 7, and 9%, respectively. Data from participation in an independent external quality-control program verified the adequacies of the method

  18. A beta-endorphin radioimmunoassay: specificity studies

    International Nuclear Information System (INIS)

    Colas-Linhart, N.; Perdrisot, R.; Petiet, A.; Bok, B.

    1986-01-01

    This note describes the technical details of a cerebrospinal fluid (CSF) B-Endorphin (B-End) radioimmunoassay (RIA). We used an antiserum raised in rabbits against human B-End which cross-reacs 100% with B-Lipotrophin (B-Lph). Thus, filtration chromatography is used to separate both peptides. The assay is sensitive (limit detection=14 pmoles/l), reproducible (the intra and inter assay coefficients of variation are 5 and 6% respectively). Specificity studies are performed to verify the cross-reactions with other opioid peptides and the non specific reactions with the biological fluid (CSF). In order to evaluate the effects of iodine-containing contrast media on the RIA, additional standard curves were analyzed in the presence of varying concentrations of two contrast materials [fr

  19. Radioimmunoassay of cholecystokinin in human plasma

    International Nuclear Information System (INIS)

    Byrnes, D.J.; Henderson, L.; Borody, T.; Rehfeld, J.F.

    1981-01-01

    A sensitive radioimmunoassay for cholecystokinin (CCK) has been developed. Porcine CCK-33 was labelled by conjugation with 125 I-hydroxyphenyl-propionic acid succinimide ester. Antibodies were raised against porcine CCK-33 covalently coupled to egg albumin. Plasma samples were extracted with 96% ethanol prior to assay. Free and bound hormone were separated by dextran-coated charcoal. The antibodies bound CCK-8 and CCK-33 with equimolar potency. The assay detection limit was 1 pmol/l plasma. Within and between assay coefficients of variation were +-12.7 and 13.0% at mean plasma CCK concentrations of 13.2 and 13.6 pmol/l. The concentration of CCK in 47 normal fasting subjects ranged from undetectable to 22 pmol/l. Ingestion of a mixed meal in 9 normal subjects increased the plasma concentration from 8.3 +- 2.5 S.E. to 24.4 +- 6.5 pmol/l. (Auth.)

  20. Effects of haemolysis, urea and bilirubin on the precision of digoxin and insulin radioimmunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Dwenger, A.; Trautschold, I.

    1982-01-01

    The influence of haemolysis, uraemia and hyperbilirubinaemia on the radioimmunoassay for both digoxin and insulin has been investigated for five separation techniques (dextran/charcoal; coated tube; polyethyleneglycol 4000; sodium sulphite; double antibody). Recoveries, and intra- and interassay precision were calculated. It was demonstrated that even in serum samples with a rather high degree of haemolysis (haemoglobin up to 50 g/l) digoxin can be measured by using each of the five separation techniques without any significant interference. Visible haemolysis (haemoglobin above 200 mg/l) leads either to disturbance or to a complete failure of insulin radioimmunoassays with all separation techniques. This effect can be largely neutralized, and precision improved, by using N-ethyl-maleimide. With the exception of the coated tube separation technique the intraassay precision has a CV of < 10%, and the interassay CV is between 10 and 20%. Elevated urea concentrations interfered in the digoxin radioimmuno-assay only when the coated tube technique was used. The insulin radioimmunoassay, however was affected by high urea when either the double antibody or the coated tube technique was used. Here the intraassay precision also has a coefficient of variation < 10%, the interassay CV lying between 10 and 20%. Bilirubin influenced the digoxin test when the sodium sulphite separation was used, and it affected the insulin determinations with polyethyleneglycol 4000 and sodium sulphite. The intra- and interassay precision were however also around 10% and between 10 and 20% respectively. Compared with the interassay precision of 15% CV for digoxin and 13% for insulin for a pool-serum from blood donors, the decrease of interassay precision caused by haemolysis, uraemia and hyperbilirubin-aemia was insignificant.

  1. Comparison of the methods for tissue triiodothyronine T(3) extraction and subsequent radioimmunoassay

    International Nuclear Information System (INIS)

    Takaishi, M.; Miyachi, Y.; Aoki, M.; Shishiba, Y.; Asahi Life Foundation, Tokyo

    1978-01-01

    Although there have been various reports on tissue T 3 concentration, the examination of the quality of radioimmunoassay has not been available. In the present study, we tried to determine whether the available methods for T 3 extraction are adequate for the various methods of T 3 radioimmunoassays used. T 3 was extracted from liver by ethanol extraction or by acid butanol extraction (Flock's method) and the extract was applied to radioimmunoassay either by Seralute T 3 column, ANS-double antibody or the ANS-charcoal method. The values of T 3 were compared with those obtained by isotope-equilibration method. The dilution curve of ethanol extract was not parallel with that of the standard in ANS-charcoal or ANS-double antibody technique. When the extract was tested by Seralate method, the dilution curve was parallel to the standard, whereas the T 3 value obtained with this method was two-fold higher than that with the isotope equilibration technique. The analysis of the ethanol extract suggested that the lipid extracted by ethanol interfered with the assay. The acid butanol extract when tested either by the ANS-double antibody or Seralate method, showed parallelism to the standard curve and gave T 3 values almost identical with those by the isotope-equilibration method. When tested by ANS-charcoal method, the dilution curve of the acid butanol extract was not parallel to the standard. Thus, to obtain reliable results, tissue extraction by Flock's method and subsequent T 3 radioimmunoassay by either ANS-double antibody or Seralate T 3 method are recommended. (author)

  2. Development of an enzyme-radioimmunoassay for the measurement of dopamine in human plasma and urine

    International Nuclear Information System (INIS)

    Faraj, B.A.; Walker, W.R.; Camp, V.M.; Ali, F.M.; Cobbs, W.B. Jr.

    1978-01-01

    An enzyme-radioimmunoassay for the measurement of dopamine is described. It is based on the incubation of plasma or urine in the presence of catechol-0-methyltransferase and S-adenosylmethionine. The 0-methylated dopamine metabolite formed (3-0-methyldopamine) was characterized by radioimmunoassay. As little as 0.5 ng of dopamine can be detected. The assay was found to be specific, since no cross-reactivity was noted for several compounds related to dopamine. The enzyme-radioimmunoassay of dopamine was used to determine the concentrations of dopamine in urine and plasma of normal volunteers. In this group, urinary dopamine averaged 182.1 +- 2.2 μg/24 hr, and the plasma concentration 0.211 +- 0.052 ng/ml. However, in children wPth neuroblastoma, there was a several-fold increase over controls in the average urinary and plasma levels of dopamine (8,500 μ/24 hr and 2.3 ng/ml). The assay was also used to monitor blood levels of dopamine following the administration of L-dopa and dopamine to patients with cardiomyopathy

  3. Preoperative Fasting Plasma C-Peptide Levels as Predictors of Remission of Type 2 Diabetes Mellitus after Bariatric Surgery: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Yan, Wenmao; Bai, Rixing; Yan, Ming; Song, Maomin

    2017-12-01

    The study evaluated the predictive role of preoperative fasting C-peptide, hemoglobin (Hb)A1c, fasting plasma glucose (FPG), and body mass index (BMI) levels on diabetes remission in patients with type 2 diabetes following bariatric surgery. Medline, PubMed, Central, and Google Scholar databases of up to September 7, 2016 were searched using the following terms: type 2 diabetes mellitus, gastric bypass, Roux-en-Y, anastomosis, C-peptide, weight loss, HbA/HbA1c, predictive/predictor. Meta-analysis of the pooled data indicated that fasting C-peptide was predictive of increased chance of remission of type 2 diabetes (pooled difference in means = 0.93, 95% confidence interval [CI] = 0.61 to 1.25, p fasting plasma C-peptide was associated with increased type 2 diabetes remission after bariatric surgery, whereas baseline HbA1c and FPG levels were associated with reduced chance of remission. These parameters may be used as a guideline in weighing the risks and benefits for surgical intervention in patients with type 2 diabetes.

  4. Radioimmunoassay of methaqualone in human urine compared with chromatographic methods

    International Nuclear Information System (INIS)

    Mule, S.J.; Kogan, M.; Jukofsky, D.

    1978-01-01

    The 125 I-radioimmunoassay for methaqualone in human urine was evaluated by a comparison with newly modified gas-liquid chromatographic and thin-layer chromatographic methods. The statistically significant sensitivity value for the radioimmunoassay was at 2 μg of methaqualone per liter of urine. The coefficient of variation was 2.88 -+ 0.16% intraassay. There was cross-reactivity only with metabolites of methaqualone, 4'-hydroxymethaqualone being twice as sensitively measured as methaqualone. There was complete agreement between results by radioimmunoassay and by gas-liquid chromatography in 96.7% of the samples analyzed. Only 1.2% of the radioimmunoassay values were false positives, and 2.1% false negatives (phi = 0.8917, P < 0.001). Comparisons between the thin-layer chromatographic data and the gas--liquid chromatographic or radioimmunoassay data showed less agreement because of the 50- to 200-fold higher sensitivity of the latter techniques. Gas--liquid chromatography therefore appears to represent the best reference method for the evaluation of the radioimmunoassay, which appears to be a very sensitive and reliable technique for detecting methaqualone and its metabolites in human urine

  5. Identification and accurate quantification of structurally related peptide impurities in synthetic human C-peptide by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Li, Ming; Josephs, Ralf D; Daireaux, Adeline; Choteau, Tiphaine; Westwood, Steven; Wielgosz, Robert I; Li, Hongmei

    2018-06-04

    Peptides are an increasingly important group of biomarkers and pharmaceuticals. The accurate purity characterization of peptide calibrators is critical for the development of reference measurement systems for laboratory medicine and quality control of pharmaceuticals. The peptides used for these purposes are increasingly produced through peptide synthesis. Various approaches (for example mass balance, amino acid analysis, qNMR, and nitrogen determination) can be applied to accurately value assign the purity of peptide calibrators. However, all purity assessment approaches require a correction for structurally related peptide impurities in order to avoid biases. Liquid chromatography coupled to high resolution mass spectrometry (LC-hrMS) has become the key technique for the identification and accurate quantification of structurally related peptide impurities in intact peptide calibrator materials. In this study, LC-hrMS-based methods were developed and validated in-house for the identification and quantification of structurally related peptide impurities in a synthetic human C-peptide (hCP) material, which served as a study material for an international comparison looking at the competencies of laboratories to perform peptide purity mass fraction assignments. More than 65 impurities were identified, confirmed, and accurately quantified by using LC-hrMS. The total mass fraction of all structurally related peptide impurities in the hCP study material was estimated to be 83.3 mg/g with an associated expanded uncertainty of 3.0 mg/g (k = 2). The calibration hierarchy concept used for the quantification of individual impurities is described in detail. Graphical abstract ᅟ.

  6. Combined radioimmunoassay of HBs-antigen and anti-HBs using the Biotest combRIA-Au kit

    International Nuclear Information System (INIS)

    Kselikova, M.; Novak, J.; Urbankova, J.

    1979-01-01

    Hepatitis B antigen and antibody were determined simultaneously by radioimmunoassay using the Biotest combRIA-Au kit. The results in determining antigens and antibodies in sera with a known content of these substances by this kit nearly equal those of isolated determinations of antigen by the Abbott AUSRIA II-125 kit, and of antibody by the Abbott AUSAB kit, resp., except for a negligible number of sera with a very low content of either antigen or antibody. (author)

  7. Insulin secretion and glucose uptake by isolated islets of the hamster. Effect of insulin, proinsulin and C-peptide

    Energy Technology Data Exchange (ETDEWEB)

    Dunbar, J C; McLaughlin, W J; Walsh, M F.J.; Foa, P P [Sinai Hospital of Detroit, Mich. (USA). Dept. of Research

    1976-01-01

    Isolated pancreatic islets of normal hamsters were perfused either in a closed or in a open system. When the buffer was recirculated and the endogenous insulin was allowed to accumulate, the islets secreted significantly less insulin than when the system was open and the endogenous insulin was washed away. The addition of monocomponent insulin or of proinsulin to the perfusion buffer significantly decreased insulin secretion. The inhibitory action of proinsulin was significantly greater than that of monocomponent insulin. C peptide had no effect. When pancreatic islets were incubated in a fixed volume of stationary buffer containing unlabeled glucose (1.0 mg or 3.0 mg/ml) and glucose-U-/sup 14/C (1.0 ..mu..C/ml), the amount of insulin secreted and the /sup 14/CO/sub 2/ produced by each islet decreased progressively as the number of islets in the sample increased. Under these conditions, the concentration of insulin required to inhibit insulin secretion increased with the concentration of glucose in the medium. Proinsulin did not alter the incorporation of leucine-4.5-/sup 3/H into total extractable insulin (insulin + proinsulin). Thus, insulin and proinsulin appear to inhibit insulin release, but not insulin synthesis.

  8. Radioimmunoassay of antidiuretic hormone. Application to rats and to man

    International Nuclear Information System (INIS)

    Fressinaud-Masdefeix, Philippe.

    1976-06-01

    The general principles of antidiuretic hormone secretion are known from kidney function explorations and the use of biological methods. Radioimmunoassay of the hormone should contribute towards a better understanding of this secretion in the fields of both physiology and pathology. After a review on antidiuretic hormone and the methods used so far for its investigation, part two of this work concentrates on the development of our own radioimmunological system applied to this hormone. The system is specific, though interference in the measurement from metabolite(s) of the hormone cannot be absolutely ruled out; reproducible, as witnessed by the 'inter-test' variation coefficient of 8%; and sensitive, since the hormone is easily measured in the urine, when secretion is slowed down. In spite of its sensitivity however the hormone determination in the plasma is not possible for a small sample volume because of the difficulty of obtaining high-affinity specific antibodies. To our knowledge only one plasma ADH determination is in common use to date. Part three is devoted to the application of this technique in rats and man, and the results obtained [fr

  9. Improved performance of a double antibody radioimmunoassay for carcinoembryonic antigen

    International Nuclear Information System (INIS)

    Zimmerman, R.

    1979-01-01

    A new double antibody solid-phase radioimmunoassay (RIA) for carcinoembryonic antigen (CEA) is critically analyzed. The aim of the study was 4-fold: (a) to define the level of sensitivity (a comparison of 3 different assay procedures revealed that the author's sequential assay was more sensitive than most previously reported RIAs, while competitive and non-equilibrium assay had wider measuring ranges); (b) to analyze recoveries of CEA in either serum, plasma or urine (the recovery , even in urine, was very close to expected values, indicating that no CEA is lost or degraded during brief storage or in the extraction procedure); (c) to evaluate inter- and intra-assay variations, since most clinical management is dependent on serial assays rather than single determinations. The coefficients of variation were low both within and between assays. A change of 3 ng CEA is required for significant change (>2 S.D.) at the normal serum level which is 16 ng CEA/ml in the authors assay. At levels above normal, a change of 4 ng is required; (d) the assay was also developed for determination of CEA levels in a large series of perchlorid acid treated serum, plasma or urine samples. This forms the basis for an assay suitable for serial assays with high sensitivity and accuracy in various neoplastic diseases. (Auth.)

  10. Development and clinical application of human gastrin radioimmunoassay

    International Nuclear Information System (INIS)

    Ginabreda, M.G.P.; Borghi, V.C.; Bettarello, A.

    1988-08-01

    The determination of human gastrin levels in the blood is very important for diagnosis of gastrointestinal disorders. This work describes the radioimmunoassay of gastrin developed according to Russell et al. and its clinical application measuring fasting levels of this hormone in normal subjects, gastrectomized, chagasics, patients with chronic renal failure (CRF), pernicious anemia (PA) and Zollinger-Ellison syndrome (ZES). Synthetic human gastrin was used for radioiodination and as standard, while the specific antibody was raised in rabbits. Gastrin was radioiodinated by a modification of the chloramine T technique and purified by anion exchange chromatography in QAE-Sephadex A-25 to a specific activity around 200 uCi/ug. The assays were performed by incubation of 125 I-gastrin, standard gastrin (zero to 500 pmol/l) or unknown samples with the antiserum for 4 days at 4 0 C. The antibody bound and free 125 I-gastrin was separated by adsorption of the latter to the charcoal. The basal gastrin values of normal subjects ranged from 2 to 74 pmol/l, being these levels higher in the chagasics (from 6 to 261 pmol/l). Higher levels of gastrin were determined in patients with CRF (from 12 to 350 pmol/l), PA (from 160 to 680 pmol/l) and with ZES(1010 pmol/l), while very low levels were confirmed in gastrectomized (from 1 to 8 pmol/l). (author) [pt

  11. Radioimmunoassay and related procedures in medicine

    International Nuclear Information System (INIS)

    1978-01-01

    Full text: Radioassay procedures for the measurement of substances such as hormones, vitamins and drugs in the body fluids and tissues, above all in the blood, are now in the front rank of medical applications of radioactive materials. These procedures, which are carried out on specimens in the medical laboratory and do not involve the administration of any radioactive material to the patient, are now widely employed in the routine diagnosis and investigation of disease, whilst their use in research has led to important advances in many branches of medicine. Typical of radioassay methods is radioimmunoassay, which depends on the antigen-antibody reaction between the substance to be measured and the antibodies in an antiserum against that substance produced in a guinea-pig, rabbit, sheep or other animal. The importance of radioimmunoassay was recently underlined by the award of the Nobel Prize in medicine for 1977 to Dr. Rosalyn Yalow of the United States of America for her pioneer work on the method over the past two decades, particularly in relation to the measurement of protein hormones. This symposium was the third on the subject to have been sponsored by the IAEA. The first took place in Vienna in 1969 and the second in Istanbul in 1973. During the four years from 1973 to 1977, the growing commercial availability of reagents and kits for radioassays brought them into routine use. This in turn led to an increasing awareness of the need for assay standardization and quality control and to an increasing attention to techniques of assay data analysis. The burgeoning demands made on assay services stimulated interest in the possibilities for automation of assay procedures. Promising new methods were developed, notably solid-phase radioassay and radioreceptor assay. At the same time there was a resurgence of interest in alternative assay methods not based on the use of radioactive materials, which made a critical re-examination of the entire subject desirable. The

  12. Radioimmunoassay and related procedures in medicine

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-02-15

    Full text: Radioassay procedures for the measurement of substances such as hormones, vitamins and drugs in the body fluids and tissues, above all in the blood, are now in the front rank of medical applications of radioactive materials. These procedures, which are carried out on specimens in the medical laboratory and do not involve the administration of any radioactive material to the patient, are now widely employed in the routine diagnosis and investigation of disease, whilst their use in research has led to important advances in many branches of medicine. Typical of radioassay methods is radioimmunoassay, which depends on the antigen-antibody reaction between the substance to be measured and the antibodies in an antiserum against that substance produced in a guinea-pig, rabbit, sheep or other animal. The importance of radioimmunoassay was recently underlined by the award of the Nobel Prize in medicine for 1977 to Dr. Rosalyn Yalow of the United States of America for her pioneer work on the method over the past two decades, particularly in relation to the measurement of protein hormones. This symposium was the third on the subject to have been sponsored by the IAEA. The first took place in Vienna in 1969 and the second in Istanbul in 1973. During the four years from 1973 to 1977, the growing commercial availability of reagents and kits for radioassays brought them into routine use. This in turn led to an increasing awareness of the need for assay standardization and quality control and to an increasing attention to techniques of assay data analysis. The burgeoning demands made on assay services stimulated interest in the possibilities for automation of assay procedures. Promising new methods were developed, notably solid-phase radioassay and radioreceptor assay. At the same time there was a resurgence of interest in alternative assay methods not based on the use of radioactive materials, which made a critical re-examination of the entire subject desirable. The

  13. C-Peptide Test

    Science.gov (United States)

    ... insulin injections or an insulin pump; when your health practitioner suspects that you have insulin resistance ; when you have documented ... Preparation Needed? Fasting for 8 to 10 hours before blood testing ...

  14. Monoclonal antibodies to human chorionic gonadotropin and their application to two-site sandwich radioimmunoassay

    International Nuclear Information System (INIS)

    Mizuchi, A.; Iio, M.; Miyachi, Y.

    1984-01-01

    Monoclonal antibodies were prepared against human chorionic gonadotropin (HCG). One monoclonal antibody recognized a conformational determinant expressed only on native HCG molecule and another monoclonal antibody had the specificity for the epitopes located on the β-subunit of HCG. Monoclonal antibodies reacting with different antigenic determinants on the HCG molecule were used to develop a simplified 2-site sandwich radioimmunoassay in which one monoclonal antibody was immobilized and another labeled with 125 iodine. This assay was highly specific for HCG and there was no cross-reactivity with α,β-subunit of HCG, luteinizing hormone and follicle stimulating hormone. (Auth.)

  15. Radioimmunoassay of CA 19-9 tumor marker in the diagnosis of thyroid cancer

    International Nuclear Information System (INIS)

    Markov, V.V.; Slavnov, V.N.; Komissarenko, I.V.; Kovpak, N.A.; Kovalenko, A.E.; Guda, B.B.

    1999-01-01

    Applicability of determining carbohydrate antigen CA 19-9 content in blood serum, tissue extracts, and thyroid tumor aspiration biopsy samples to the differential diagnosis of benign and malignant tumors of thyroid is studied. Radioimmunoassay was used for measurements. It is shown that determination of marker CA 19-9 in blood serum is not informationally capable for the differential diagnosis of thyroid tumors. Considerable increase in CA 19-9 concentration was found in tumor aspiration biopsy samples from patients with malignant tumors this fact can be used for preoperative diagnosis of thyroid cancer [ru

  16. Possible application of tumor marker radioimmunoassay in diagnosis of testicular and prostatic carcinomas

    Energy Technology Data Exchange (ETDEWEB)

    Kausitz, J

    1988-10-01

    Determinations of alpha fetoprotein and chorionic gonadotropin levels by radioimmunoassay in 340 patients with germ cell tumors of the testes have confirmed that tumor markers are suitable prognostic parameters, facilitate assessment of the clinical stage, are sensitive parameters of the efficacy of chemotherapy and enable early detection of relapses. In a group of 71 patients with prostate cancer, systematic determination of prostate specific antigen levels proved to be a reliable method of monitoring and a sensitive method of detecting remote metastases. (author). 5 figs., 13 tabs., 23 refs.

  17. 1 α-hydroxycholecalciferol-25-hydroxy esters and their use in radioimmunoassay

    International Nuclear Information System (INIS)

    Fairney, A.; Baggiolini, E.; Uskokovic, M.R.

    1981-01-01

    The invention relates to the determination of 1 α, 25-dihydroxycholecalciferol and of optical enantiomers and racemates thereof. More particularly, the invention is concerned with a radioimmunoassay and a reagent for the determination of 1 α, 25-dihydroxycholecalciferol and of optical enantiomers and racemates thereof, with novel antigens and antibodies useful in the said process and with a process for the preparation of the said antigens and antibodies. The invention is also concerned with novel haptens useful in the preparation of said antigens and with a process for the preparation of said haptens. (author)

  18. Radioimmunoassay of total IgE and allergen-specific IgE antibodies with a uniform indicator system in allergies of childhood

    International Nuclear Information System (INIS)

    Struy, H.; Schuster, R.; Sollich, V.; Thal, W.; Morenz, J.

    1984-01-01

    Solid-phase radioimmunoassays for the determination of allergen-specific and total IgE have been developed. In an indirect solid-phase radioimmunoassay for the measurement of allergen-specific antibodies PVC blisters coated with allergens and in a sandwich solid-phase radioimmunoassay blisters coated with antihuman IgE antibodies are incubated sequentially with patient serum, unlabelled antihuman IgE from rabbits purified by affinity chromatography, and finally with antirabbitglobulin from sheep. Antirabbitglobuline was purified by immunoadsorption. The 125 I-labelled antibody with a specific activity of 30 kBq/μg antibody protein could be used universally for the determination of antibodies of each immunoglobulin class. In 160 patients mostly with seasonal asthma these assays supported RAST and PRIST kits and were helpful in the diagnosis of atopic diseases. (author)

  19. Radioimmunoassay in the diagnosis of atypical form of thyrotoxicosis

    Energy Technology Data Exchange (ETDEWEB)

    Livshits, G.Ya.

    1984-11-01

    Fifty-six patients with ''unmotivated'' disorder of the cardiac rhythm were examined. A combined radionuclide study including a study of iodoabsorptive function with a standard technique, thyroid visualization and determination of the thyroxin, triiodothyronine level in the blood serum with the radioimmunoassay using standard diagnostic kits, was conducted, Latent thyroid hyperfunction was revealed in 24 patients (42.8%). Study of iodoabsorptive function revealed pathological changes in 8 patients only, whereas raaioimmunoassay revealed a significant elevation of the peripheral thyroid hormone level as compared to that of the control group in 24 patients. The conclusion is that patients with ''unmotivated'' disorder of the cardiac rhythm often suffer from latent thyrotoxicosis which is the main etiological factor and trigger mechanism of arrhythmias. In such a situation they are the only clinical symptom of thyrotoxicosis that makes it possible to regard this form of disease as monosymptomatic. The early detection of the cause of cardiac rhythm disorder and the prescription of pathogenetic thyrostatic therapy resulted in the return of the cardiac cycle rate to normal in all the patients with sinus tachycardia and prevented relapses of the paroxysmal forms of rhythm disorder.

  20. The radioimmunoassay of serum alpha-fetoprotein levels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y H; Choi, K A; Ahn, K S; Suh, W H; Lee, M J [Korea University College of Medicine, Seoul (Korea, Republic of)

    1982-06-15

    Alpha-fetoprotein (AFP) was first described in the human fetus in 1956 and became a marker protein of primary liver cancer in adults. Serum AFP levels were measured by radioimmunoassay in 212 patients with a variety of malignant and nonmalignant diseases to determine the incidence of leveis elevated above 40 ng/ml. The results obtained are as follows: In 44 cases of total 212 patients, abnormal AFP levels above 40 ng/ml in serum were measured; 24 of 31 patients with primary hepatocellular carcinoma and primary hepatocellular carcinoma with liver cirrhosis (77.4%), 7 of 51 patients with only liver cirrhosis (13.7%), 4 of 10 patients with metastatic liver cancer (40.0%), 4 of 15 patients with chronic hepatitis (26.7%), 2 of 23 patients with acute hepatitis (8.7%), and each one patient with 6 pancreatic carcinoma and 9 cholangiocarcinoma had elevated serum AFP levels. One pregnant woman with gestation 35 weeks had elevated level, but within normal limit during pregnancy.

  1. The radioimmunoassay of serum alpha-fetoprotein levels

    International Nuclear Information System (INIS)

    Kim, Y. H.; Choi, K. A.; Ahn, K. S.; Suh, W. H.; Lee, M. J.

    1982-01-01

    Alpha-fetoprotein (AFP) was first described in the human fetus in 1956 and became a marker protein of primary liver cancer in adults. Serum AFP levels were measured by radioimmunoassay in 212 patients with a variety of malignant and nonmalignant diseases to determine the incidence of leveis elevated above 40 ng/ml. The results obtained are as follows: In 44 cases of total 212 patients, abnormal AFP levels above 40 ng/ml in serum were measured; 24 of 31 patients with primary hepatocellular carcinoma and primary hepatocellular carcinoma with liver cirrhosis (77.4%), 7 of 51 patients with only liver cirrhosis (13.7%), 4 of 10 patients with metastatic liver cancer (40.0%), 4 of 15 patients with chronic hepatitis (26.7%), 2 of 23 patients with acute hepatitis (8.7%), and each one patient with 6 pancreatic carcinoma and 9 cholangiocarcinoma had elevated serum AFP levels. One pregnant woman with gestation 35 weeks had elevated level, but within normal limit during pregnancy

  2. Multiple steroid radioimmunoassays and automation. Versatile techniques for reproductive endocrinology

    International Nuclear Information System (INIS)

    Vihko, R.; Hammond, G.L.; Pakarinen, A.; Viinikka, L.

    1978-01-01

    The combination of the efficient steroid-separating properties of a lipophilic Sephadex derivative Lipidex-5000sup(TM) and the use of antibodies with carefully selected specificity allows the quantitative determination of pregnenolone, progesterone, 17α-hydroxyprogesterone, androstenedione, testosterone, 5α-dihydrotestosterone, 5α-androstanedione, androsterone and 5α-androstane-3α, 17β-diol in 1- to 2-ml samples of both blood serum and amniotic fluid as well as in 300- to 600-mg pieces of prostatic tissue. The adaptation of the pipetting unit and incubator of a discrete clinical chemical analyser, System Olli 3000, for the automation of the radioimmunoassays has resulted in a greatly increased through-put and has decreased the experimental error of the procedure. In studies on reproductive endocrinology, the methodology developed has allowed the detection of a sex difference in androgen composition of the amniotic fluid early in pregnancy. Further, it is very likely that the decline in steroid production by the testis seen during the first year of life and then in senescence is affected by basically different mechanisms. There are also important differences in the steroid content of normal, hyperplastic and carcinomatous prostate. (author)

  3. Multiple steroid radioimmunoassays and automation: versatile techniques for reproductive endocrinology

    International Nuclear Information System (INIS)

    Vihko, R.; Hammond, G.L.; Pakarinen, A.; Viinikka, L.

    1977-01-01

    The combination of the efficient steroid separating properties of a lipophilic Sephadex derivative Lipidex-5000sup(TM), with the use of antibodies with carefully selected specificity allows the quantitative determination of pregnenolone, progesterone, 17α-hydroxyprogesterone, androstenedione, testosterone, 5α-dihydrotestosterone, 5α-androstanedione, androsterone and 5α-androstane-3α, 17β-diol from 1-2 ml samples of blood serum, amniotic fluid or 300-600 mg pieces of prostatic tissue. The adaptation of the pipetting unit and incubator of a discrete clinical chemical analyzer, System Olli 3000, for the automation of the radioimmunoassays has resulted in a greatly increased through-put and decreased experimental error of the procedure. In studies on reproductive endocrinology, the methodology developed has allowed the detection of a sex difference in androgen composition of the amniotic fluid early in pregnancy. Further, it is very likely that the decline in steroid production by the testis seen during the first year of life and then in senescence is affected by basically different mechanisms. There are also important differences in the steroid content of normal, hyperplastic and carcinomatous prostate. (orig.) [de

  4. Radioimmunoassay of antidiuretic hormone in human urine. Applications

    International Nuclear Information System (INIS)

    Zebidi, Abdelkrim.

    1977-10-01

    This work is devoted mainly to the development of a radioimmunological system of antidiuretic hormone (ADH) determination in the urine and its physiological and pathological applications. The radioimmunological method thus replaces the biological measurement of antidiuretic hormone in the urine. This new technique was not possible until specific arginine vasopressin antibodies were obtained and a labelled hormone was prepared according to the criteria set for a radioimmunoassay. The labelled hormone is lysine vasopressin (greater stability). Although 125 I-LVP has lost most of its biological activity the molecule keeps all its immunological properties, behaving in the same way as non-iodinated synthetic LVP towards anti-LVP antibodies. Once specific antivasopressin antibodies and immunologically competent labelled hormone were available, conditions were defined for the radioimmunological ADH test in the urine. This technique, relatively easy to use, allows twenty samples to be measured simultaneously. With this sensitive, specific and reproducible method, it is thus possible to estimate the urinary ADH excretion rates from a 20 ml volume of urine after previous extraction on amberlite CG 50. This extraction method is aimed at both concentrating the hormone and eliminating non-specific interferences. The hormone extraction yield is about 92%+-8 [fr

  5. Separation of lactoferrin and clinical application of its radioimmunoassay

    International Nuclear Information System (INIS)

    Qiang Yizhong; Wang Chongdao; Jin Jian

    1995-02-01

    A new method of separation and purification of lactoferrin (LF), its radioimmunoassay (LF-RIA), and application in the diagnosis of lung cancer are reported. The results showed that this method is much better than what were previously reported, with advantages of high yield, time-saving and economy. The results of the LF-RIA established were good. The coefficients of variation within a batch and between batches were 4.77% and 13.59% respectively and the recovery rate was 97.99%. There was no cross-reaction between lactoferrin and transferrin. The lactoferrin in the bronchial washing fluid (BLF) was determined in 36 lung cancer cases, 21 pulmonary infection cases and 4 normal controls. The results indicated that the BLF content in the lung cancer group was higher than that in the pulmonary infection group or the normal control group and the detection rate was the highest in lung adenocarcinoma. Pathological analysis indicated that the BLF was negatively related to the early and later tumor. (2 figs., 2 tabs.)

  6. Radioimmunoassay of human cardiac tropomyosin in acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, P; McGurk, B; Littler, W A [Queen Elizabeth Hospital, Birmingham (UK)

    1981-03-01

    Tropomyosin was prepared from fresh human myocardium and antisera raised in rabbits. A sensitive radioimmunoassay was developed for the detection of human cardiac /sup 125/I-labelled tropomyosin in human sera down to levels of 1 ng/ml. Values for human cardiac tropomyosin in normal patients ranged from less than 1 to 3 ng/ml. In 18 patients with acute myocardial infarction all had elevated tropomyosin levels ranging from 41 to above 200 ng/ml with a mean peak level of 101 ng/ml. In this study there were no false positive or false negative results. In the initial stages of infarction the time course of appearance and peak levels of cardiac tropomyosin, total creatine kinase and creatine kinase MB isoenzyme were similar. Although total creatine kinase and creatine kinase MB isoenzyme levels were normal after 72 h in patients with single, uncomplicated infarction, cardiac tropomyosin levels were still significantly elevated above normal after this time, being 30-60% of peak valuctional hourly rate of absorption and the plasma /sup 32/P radioactivity at 60 min corrected for extracellular fluid volume provided the best app elements, the characteristics of which are determined by employing the Lagrange multiplier concept. Unknowns of the resulting simultaneous equation consist of usual nodal displacements of the whole stru element codes. Therefore, FAST should be useful in several areas for which all other codes are too unwieldy and expensivnt makers was established, in which the investigations and studies have started.

  7. Radioimmunoassay in the diagnosis of atypical form of thyrotoxicosis

    International Nuclear Information System (INIS)

    Livshits, G.Ya.

    1984-01-01

    Fifty-six patients with ''unmotivated'' disorder of the cardiac rhythm were examined. A combined radionuclide study including a study of iodoabsorptive function with a standard technique, thyroid visualization and determination of the thyroxin, triiodothyronine level in the blood serum with the radioimmunoassay using standard diagnostic kits, was conducted, Latent thyroid hyperfunction was revealed in 24 patients (42.8%). Study of iodoabsorptive function revealed pathological changes in 8 patients only, whereas raaioimmunoassay revealed a significant elevation of the peripheral thyroid hormone level as compared to that of the control group in 24 patients. The conclusion is that patients with ''unmotivated'' disorder of the cardiac rhythm often suffer from latent thyrotoxicosis which is the main etiological factor and trigger mechanism of arrhythmias. In such a situation they are the only clinical symptom of thyrotoxicosis that makes it possible to regard this form of disease as monosymptomatic. The early detection of the cause of cardiac rhythm disorder and the prescription of pathogenetic thyrostatic therapy resulted in the return of the cardiac cycle rate to normal in all the patients with sinus tachycardia and prevented relapses of the paroxysmal forms of rhythm disorder

  8. Evidence for carcinoembryonic antigen using radioimmunoassay and enzyme immunoassay

    International Nuclear Information System (INIS)

    Kungda Gao, L.

    1980-01-01

    A commercially available radioimmunoassay for the determination of carcinoembryonic antigen (CEA) was initially compared with an enzyme immunoassay (EIA). Considerable differences were found between the individual value. For three patients suffering from carcinomas of the digestive tract a better indication of the disease was given in the RIA than in the EIA. A further 110 patients with various illnesses were examined for serum CEA-levels using RIA. A method for measuring CEA in feces by RIA was developed. The normal range lies below 300 ng/ml. This assay could be of significance for the early recognition of colo-rectal carcinoma. In part II of this dissertation CEA was isolated from colo-rectal carcinomas using three different gel filtration media. It was only possible to obtain almost pure CEA (24 μg CEA per μg protein) by one of the methods. Six guinea pigs were immunized with the isolated CEA and all developed antibodies. The isolated CEA was labelled with 125 I and an own RIA saturation sequence and double antibody separation was developed. One of the antisera was able to distinguish without overlap 7 healthy patients from 7 suffering from colo-rectal carcinomas in non-extracted serum. (orig./MG) [de

  9. A radioimmunoassay for lignin in plant cell walls

    International Nuclear Information System (INIS)

    Dawley, R.M.

    1989-01-01

    Lignin detection and determination in herbaceous tissue requires selective, specific assays which are not currently available. A radioimmunoassay (RIA) was developed to study lignin metabolism in these tissues. A β-aryl ether lignin model compound was synthesized, linked to keyhole limpet hemocyanin using a water-soluble carbodiimide, and injected into rabbits. The highest titer of the antiserum obtained was 34 ηg/mL of model derivatized BSA. An in vitro system was developed to characterize the RIA. The model compound was linked to amino activated polyacrylamide beads to mimic lignin in the cell walls. 125 I Radiolabelled protein A was used to detect IgG antibody binding. The RIA was shown in the in vitro system to exhibit saturable binding. The amount of antibody bound decreased when the serum was diluted. Immunoelectrophoresis and competitive binding experiments confirmed that both aromatic rings of the lignin model compound had been antigenic. Chlorogenic acid, a phenolic known to be present in plant cells, did not compete for antibody binding. The RIA was used to measure lignin in milled plant samples and barley seedlings. Antiserum binding to wheat cell walls and stressed barley segments was higher than preimmune serum binding. Antibody binding to stressed barley tissue decreased following NaClO 2 delignification. The RIA was found to be less sensitive than expected, so several avenues for improving the method are discussed

  10. Radioimmunoassay of erythropoietin: analytical performance and clinical use in hematology.

    Science.gov (United States)

    Schlageter, M H; Toubert, M E; Podgorniak, M P; Najean, Y

    1990-10-01

    We report here the performance of a recently commercialized radioimmunoassay kit for determining erythropoietin (EPO) in serum or plasma. The lower detection limit of the method was 3 U/L. Precision, analyzed by the variation coefficients between different assay runs and in the same experiment, was always less than 10%; accuracy was assessed by recovery and dilution tests. In anemic patients (hematocrit 18-39%), the concentration of EPO was logarithmically related to hematocrit. A relatively large dispersion of the results was noted, as reported by others with various RIAs. Patients with severe renal failure demonstrated a very low EPO value, whatever the degree of their anemia. In some chronic anemias resulting from malignancy, EPO concentrations were also relatively low. In the polycythemia vera group, the EPO mean was below normal for greater than 95% of the patients, whatever their clinical stage (first evaluation, relapse, or remission). In contrast, 91% of the patients with pure erythrocytosis had a normal or increased EPO value, even when the etiology was unknown. Measurement of EPO concentration may be useful for the clinical differentiation of myeloproliferative disorders and, subsequently, for their prognosis and choice of treatment.

  11. Radioimmunoassay of fibrinopeptide A: Modifications of technique and clinical trials

    International Nuclear Information System (INIS)

    Schmid, M.

    1981-01-01

    In 1971 Nossel and coworkers developed a highly sensitive radioimmunoassay for the determination of plasma concentration of fibrinopeptide A. Our own experience gained using this test is reported here as well as a number of improvements in methodology which have not only led to a shortening of the whole test procedure to one day but also to greater ease of handling. The modifications concern a gel adsorption procedure for the extraction of FPA from defibrinated plasma samples, the double antibody method for separating free and antibody-bound tracer-phase in assay and automatic evaluation of test results with the aid of a suitable computer programme. Considerations concerning the specificity of conclusions drawn from the test, in particular the necessity of keepin gout interfering plasmin-induced fibrinogen break-down products, play an important role in all changes of methodology. An attempt was made to define a normal range for FPA-plasma levels and a mean value of 1.51 ng/ml at a standard deviation of 0.69 ng/ml was obtained from 42 clinically healthy test patients. Pathologically evaluated FPA-levels were regularly found in patients with septic or thrombotic illness. (orig./MG) [de

  12. An improved method for estradiol-17B radioimmunoassay

    International Nuclear Information System (INIS)

    El-Banna, I.M.; El-Asrag, H.A.; Gamal, M.H.

    1991-01-01

    This work describes an improved radioimmunoassay (RIA) of serum estradiol-17 B (E) using locally generated immuno-chemicals. Estradiol hemisuccinate (E -3-H S) was prepared and conjugated to bovine serum albumin (BSA). The obtained conjugate; E 3-H S: BSA, hadλ max at 280 mu and the steroid BSA molar ratio was 25:1. The immunogen was injected subcutaneously in New Zealand rabbits and large amount of antiserum was harvested with 1 : 10500 antibody titre. The antibody cross reactions with estrone (E ), estriol (E ) and progesterone (P) were determined. Blood samples were collected from cycling Osemi ewes during follicular phase, pregnant ewes near term and daily from a cycling ewe over two consecutive estrous cycles. Serum samples were analysed for E both directly and after diethyl ether extraction (DE). The higher E values were found in the direct assay for pregnant ewes. The direct serum minnature RIA system, described herein, was found to be specific, sensitive, precise and economic.5 fig. 2 tab

  13. Development and validation of a new radioimmunoassay for parathyrin (PTH)

    International Nuclear Information System (INIS)

    Kao, P.C.; Jiang, N.S.; Klee, G.G.; Purnell, D.C.

    1982-01-01

    A radioimmunoassay for human parathyrin has been developed and characterized with whole-molecule (residues 1-84) human parathyrin and with the 1-34, 44-68,and 53-84 amino acid residue fragments of it. The antiserum used reacted with the whole molecule and with the 44-68 and 53-84 fragments, but not with the 1-34 fragment. Parathyrin concentrations in the serum of 118 normal subjects and of 112 patients with surgically proved primary hyperparathyroidism were determined with this assay. The mean results were 39 (SD 13) μL-Eq/mL for the normals and 111 (SD 77) μL-Eq/mL for the patients with primary hyperparathyroidism (p < 0.0005). The upper 95% confidence limit of the normal range was 60 μL-Eq/mL. For 54 patients with primary hyperparathyroidism, the preoperative values for serum parathyrin, calcium, and phosphate-but not creatinine-were statistically different from the postoperative values (paired t-test, p <0.0005). Normal subjects showed significant (p <0.0005) differences in serum calcium concentrations but not in parathyrin concentrations, compared with concentrations found in cancer patients and patients who had thiazide induced hypercalcemia. Phosphate concentration in serum, although not a specific indicator of disease, is a valuable clue to the diagnosis of primary hyperparathyroidism

  14. The radioimmunoassay of clomipramine (Anafranil-Geigy): a tricyclic antidepressant

    International Nuclear Information System (INIS)

    Read, G.F.; Riad-Fahmy, D.

    1977-01-01

    A radioimmunoassay has been developed for the tricyclic antidepressant, clomipramine (Anafranil-Geigy) which allows accurate determination of plasma levels without a pr-assay purification step. This is achieved by generation of specific antisera using an antigen produced by conjugation of clomipramine to bovine serum albumin via the 10,11 bridge positions. As expected cross reaction of the pharmacologically active major metabolite, desmethylclomipramine was 5% and that of didesmethyclomipramine 1%. Specificity was confirmed by comparing titres achieved in the routine assay with those observed in an assay incorporating a pre-assay thin layer chromatographic purification step. Pharmacokinetic data were in agreement with double radioisotope derivative assays and also with previously reported assays using G.C. or G.C./M.S. techniques. The sensitivity is superior to any previous assay known to us for this class of compound. The specificity and precision, coupled with the high sample turnover (greater than 300 samples/week per technician) make the assay ideal for supervision of patient compliance and routine assay of samples generated in large clinical trials. (orig.) [de

  15. Radioimmunoassay and the hormones of thyroid function

    International Nuclear Information System (INIS)

    Stahl, R.J.

    1975-01-01

    Radioimmunoassay (RIA) has provided the tools for wide-reaching investigations that have changed and continue to change many important concepts of thyroid physiology and pathophysiology. The RIA for human thyrotropin (TSH) was developed in 1965; development of the RIA for triiodothyronine (T 3 ), thyroxine(T 4 ), thyroxine-binding globulin (TBG), and recently, thyrotropin-releasing hormone (TRH) and thyroglobulin (Tg) followed. The capacity to measure nanogram and picogram concentrations with relative ease and speed has permitted the demonstration of dynamic relationships of the intrathyroidal and circulating thyroid hormones to each other and to the pituitary and hypothalamic regulating hormones. Evidence for the presence of cross-influences between TRH and other hypothalamic regulating hormones on the secretion of pituitary hormones has accumulated. The impact of the new information on clinical practice is now becoming evident. There is new appreciation of the value of assaying serum T 3 and TSH concentrations in the clinical management of patients with disturbed function of the thyroid, pituitary, or hypothalamus. The necessary components for RIA performance can be purchased separately or in kit form from commercial sources. With appropriate quality-control procedures, precise, sensitive, and reliable data can be generated. Awareness of the specific technical problems relating to the RIA of these hormones is absolutely necessary to assure reliable results. The availability of kits or their components permits the performance of these studies in the community hospital and in reliable commercial-service laboratories. (U.S.)

  16. Chemical Kinetics of Progesterone Radioimmunoassay System

    International Nuclear Information System (INIS)

    Abdel-Fattah, A.A.; Moustsfs, K.A.; El-Kolally, M.T.

    2004-01-01

    Progesterone is one of the steroids secreted by the corpus Iuteum in females during the menstrual cycle, and in a much higher amount by the placenta during pregnancy. It is also secreted in a minor quantities by the adrenal cortex in both males and females. Measurement of serum progesterone represents one of diagnostic values in menstrual disorders and infertility. The progesterone radioimmunoassay is based on the competition between unlabelled progesterone and a fixed quantity of 125 I-labeled progesterone for a limited number of binding sites on progesterone specific antibody. Allowing for a fixed amount of magnetizable immunosorbent to react, the antigen-antibody complex is bound on solid particles which are then separated by magnetic rack, and the radioactivity of the solid phase was counted using gamma counter. In this work, the chemical kinetics of the assay was followed, where the specific rate constant (K) was calculated at 4 degree and 37 degree and the activation energy (E act ) were calculated and the reaction rate was deduced

  17. Radioimmunoassay in developing countries: General principles

    Energy Technology Data Exchange (ETDEWEB)

    Piyasena, R D

    1993-12-31

    Radioimmunoassay (RIA) is probably the most commonly performed nuclear medicine technique. It is an in vitro procedure, where no radioactivity is administered to the patient. But this alone is not the reason for its widespread use. It provides the basis for extremely sensitive and specific diagnostic tests, and its use in present day medicine has brought a virtual information explosion in terms of understanding the pathophysiology of many diseases. The fact that the technology involved is within the technical and economic capabilities of the developing world is evident from the increasing demand for its introduction or expansion of existing services. RIA facilities need not be restricted to urban hospitals, as in the case of in vivo nuclear medicine techniques, but may be extended to smaller district hospitals and other laboratories in peripheral areas. It is also possible to send blood samples to a central laboratory so that a single centre can serve a wide geographical area. There are many laboratories in the industrialized world that receive a major proportion of samples for assay by mail. In recent years, substantial RIA services have been established in many of the developing countries in Asia and Latin America. The International Atomic Energy Agency (IAEA) and World Health Organisation (WHO) have made vital contributions to these activities and have played a catalytic role in assisting member states to achieve realistic goals. In the past five years, more than 250 individual RIA laboratories in developing member states have been beneficiaries of IAEA projects

  18. Radioimmunoassay study of neurophysins in human plasma

    International Nuclear Information System (INIS)

    Reinharz, A.C.; Tissot-Berthet, M.-C.; Vallotton, M.B.

    1978-01-01

    Using a homologous system we have developed a specific and sensitive radioimmunoassay for the measurement of one of the human neurophysins in unextracted human plasma. This neurophysin is specifically secreted in response to oestrogen and has therefore been referred to as human oestrogen-stimulated neurophysin (h-OeSN). The plasma concentration was 0.57 plus minus 0.17 ng/ml (SD) in females and 0.88 plus minus 0.76 ng/ml (SD) in males. This difference is not significant. In women on oral contraceptives, plasma h-OeSN was 2.0 plus minus 1.1 ng/ml. During pregnancy h-OeSN increased progressively to 3.7 plus minus 2.9 ng/ml at the end of the first trimester, and 5.2 plus minus 2.8 ng/ml at term. Plasma h-OeSN concentrations increased rapidly and markedly in men treated with ethinyl-oestradiol. We have also demonstrated the presence of h-OeSN in amniotic and cerebrospinal fluids. A second human neurophysin, which is stimulated by nicotine but not by oestrogen, was also measured. This neurophysin was monitored by a heterologous system using antiserum raised against bovine neurophysin II (b-NII), and b-NII as the standard and tracer. (author)

  19. Radioimmunoassay of creatine kinase BB isoenzyme

    Energy Technology Data Exchange (ETDEWEB)

    Jianguo, Geng [Shanghai Medical Univ. (China). Zhongshan Hospital; and others

    1988-11-01

    A radioimmunoassay of creatine kinase BB isoenzyme (CK-BB) was developed by using CK-BB purified from human brain. The CK-BB antiserum was raised by immunizing rabbite and {sup 125}I-CK-BB iodinated with Bolton-Hunter reagent. The affinity constant was 3.0 x 10{sup 9} mol/L. No cross reactions with creatine kinase MM isoenzyme and neuron-specific enolase were found. The measuring range was 3.5 x 10{sup -8} {approx} 1.2 x 10{sup -5} mmol/L, the average recovery rate 97.5%, with the inter and intrassay CV 3.1% and 12%, respectively. The average serum CK-BB concentration in 83 normal persons was 1.5 x 10{sup -7} +- 8.1 x 10{sup -8} mmol/L, quite different from the values of acute myocardial infarction (5.2 x 10{sup -6} +- 1.2 x 10{sup -4} mmol/L, n = 28) and cerebral vascular accident (8.4 x 10{sup -4} +- 5.0 x 10{sup -4} mmol/L, n = 10).

  20. Radioimmunoassay of bovine heart protein kinase

    International Nuclear Information System (INIS)

    Fleischer, N.; Rosen, O.M.; Reichlin, M.

    1976-01-01

    Immunization of guinea pigs with bovine cardiac cAMP-dependent protein kinase (ATP : protein phosphotransferase, EC 2.7.1.37) resulted in the development of precipitating antibodies to the cAMP-binding subunit of the enzyme. Both the phosphorylated and nonphosphorylated cAMP-binding protein of the protein kinase reacted with the antiserum. A radioimmunoassay was developed that detects 10 ng of holoenzyme and permits measurement of enzyme concentrations in bovine cardiac muscle. Bovine liver, kidney, brain, and skeletal muscle contain protein kinases which are immunologically identical to those found in bovine cardiac muscle. However, the proportion of immunoreactive enzyme activity differed for each tissue. All of the immunologically nonreactive enzyme in skeletal muscle and heart was separable from immunoreactive enzyme by chromatography on DEAE-cellulose. Rat tissues and pig heart contained protein kinase activity that cross reacted immunologically in a nonparallel fashion with bovine cardiac enzyme. These results indicate that cAMP-dependent protein kinases within and between species are immunologically heterogeneous

  1. Radioimmunoassay of arginine vasopressin in human plasma

    International Nuclear Information System (INIS)

    Uhlich, E.; Weber, P.; Groeschel-Stewart, U.; Roeschlau, T.; Wuerzburg Univ.

    1975-01-01

    Antibodies for the radioimmunoassay of arginine vasopressin (AVP) described here were produced in rabbits using synthetic AVP coupled to rabbit γ-globulin with carbodiimide. In three out of six rabbits, significant antibody titres were obtained. Using the best antisera produced, 40% of labelled AVP was bound at a final dilution of 1 : 50,000. After iodination of synthetic AVP with 125 I using the chloramin-T method, a gel filtration on Sephadex G-25 was performed to purify the iodinated AVP. For separation of antibody bound and free hormone, a second antibody precipitation was used. There was no crossreactivity with oxytocin. AVP was extracted from plasma after ammoniumsulfate precipitation of the proteins by adsorption to Florisil. The recovery of AVP added to plasma in amounts of 5-25 pg/ml was 60 +- 15% (n = 6). The minimum amount of AVP detectable was 1 pg per ml plasma. The plasma level in normal adults under standard conditions was 3.4 +- 2.2 pg/ml. This is in agreement with data recently published by other researchers. The applicability and reproducibility was further tested in measurements of samples taken hourly during the entire day under water diuresis and after hormonal stimulation of AVP. (orig.) [de

  2. Falsely elevated triiodothyronine values in radioimmunoassay

    International Nuclear Information System (INIS)

    Skovsted, L.; Moelholm Hansen, J.E.; Nygaard, B.

    1995-01-01

    Five patients with falsely elevated serum triiodothyronine (T 3 ) concentrations (>9 nmol/l) in a radioimmunoassay are reported. The high T 3 -values disagreed with the other thyroid variables investigated as well as with the clinical observations. In sera from all patients a normal non-specific binding of T 3 was found, thus excluding abnormal serum-protein-binding of the hormone. An ethanol extraction of T 3 from serum before RIA reduced the T 3 content in serum from all patients to normal levels (2.0-2.4 nmol/l). These findings indicate the presence in the sera of substances, probably of protein nature, that were interfering with the assay by binding the reagent-antibody and not the antigen. Addition of non-immune rabbit serum prevented this interference and normalized the T 3 -values (1.8-2.4 nmol/l). Thus the interfering substance in T 3 -RIA could be an anti-rabbit antibody, the interaction of which can be eliminated by a minor modification of the assay making it possible to differentiate true from false T 3 -values. (au) 16 refs

  3. Combined radioimmunoassay for triiodothyronine and thyroxine

    International Nuclear Information System (INIS)

    Denning, C.E.; Schick, L.A.

    1980-01-01

    A method for the combined radioimmunoassay for the hormones triiodothyronine (T-3) and thyroxine (T-4) in serum or plasma, wherein the radiolabeled t-3 and t-4 reagents are t-3 and t-4 labeled with the same radioisotope. The hormones are extracted from the serum or plasma sample and separated from their binding proteins by adsorption to a crosslinked dextran gel at a highly alkaline ph. After washing away the dissociated proteins, a predetermined limiting amount of t-3 antibody is incubated with the gel and thereafter radiolabeled t-3 which has become extracted from the gel by antibody binding is washed away. Excess t-3 antibody and a predetermined limiting amount of t-4 antibody are then incubated with the gel and radiolabeled t-3 and t-4 which has become extracted from the gel by antibody binding are thereafter washed away. The respective relative amounts of radiolabeled t-3 and t-4 retained by the gel after the incubations with the respective limiting amounts of t-3 and t-4 antibody are compared with standard results to quantitate the hormones in the sample. The use of excess t-3 antibody in the t-4 antibody incubation is critical to the accuracy of the method, enabling the use of the same radioisotope for radiolabeling t-3 and t-4

  4. Radioimmunoassay in developing countries: General principles

    International Nuclear Information System (INIS)

    Piyasena, R.D.

    1992-01-01

    Radioimmunoassay (RIA) is probably the most commonly performed nuclear medicine technique. It is an in vitro procedure, where no radioactivity is administered to the patient. But this alone is not the reason for its widespread use. It provides the basis for extremely sensitive and specific diagnostic tests, and its use in present day medicine has brought a virtual information explosion in terms of understanding the pathophysiology of many diseases. The fact that the technology involved is within the technical and economic capabilities of the developing world is evident from the increasing demand for its introduction or expansion of existing services. RIA facilities need not be restricted to urban hospitals, as in the case of in vivo nuclear medicine techniques, but may be extended to smaller district hospitals and other laboratories in peripheral areas. It is also possible to send blood samples to a central laboratory so that a single centre can serve a wide geographical area. There are many laboratories in the industrialized world that receive a major proportion of samples for assay by mail. In recent years, substantial RIA services have been established in many of the developing countries in Asia and Latin America. The International Atomic Energy Agency (IAEA) and World Health Organisation (WHO) have made vital contributions to these activities and have played a catalytic role in assisting member states to achieve realistic goals. In the past five years, more than 250 individual RIA laboratories in developing member states have been beneficiaries of IAEA projects

  5. Estimation of urinary angiotensin II by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Fukuchi, S [Tohoku Univ., Sendai (Japan). School of Medicine

    1974-11-01

    Urine samples were collected from fasting subjects after maintaining posture for 2 hr in early morning. Urinary angiotensin II was extracted with SE-Sephadex. The extracts, after being dissolved in phosphate buffer, pH 7.5, were measured by radioimmunoassay. Recovery, sensitivity and accuracy were found to be satisfactory. The normal values obtained from 6 subjects were 52-280 pg/2 hr. The values were almost normal in essential hypertension and in chronic glomerulonephritis. They were high in 3 out of 6 cases with renovascular hypertension and subsequently dropped after surgery. In 6 cases with primary aldosteronism, very low levels were found. These increased after the removal of adrenal adenomas. No positive correlation between simultaneous plasma and urinary angiotensin samples was apparent. Also no positive correlation between urinary angiotensin and urine volume was found. In renovascular hypertention, during glucose infusion, lower values in urine volume and angiotensin excretion were observed on the stenotic side as compared to the intact side. Thus, the angiotensin excretion rate does not appear to be regulated by arterial angiotensin concentration, but rather by the angiotensin perfusion rate.

  6. Serum erythropoietin levels by radioimmunoassay in polycythaemia

    Energy Technology Data Exchange (ETDEWEB)

    Birgegaard, G.; Miller, O.; Caro, J.; Erslev, A. (Cardeza Foundation for Hematological Research, Jefferson University, Philadelphia, Pa.)

    1982-01-01

    A radioimmunoassay (RIA) method for erythropoietin (Epo) was developed and validated against the polycythaemic mouse assay. The correlation was good, with a r=0.94. Several other criteria of specificity were also filled by the RIA, which had a lower detection limit of 5 mU/ml. The mean serum-Epo level in 6 patients with secondary polycythaemia, 50.2 +- 26.2 mU/ml, was significantly higher than in a group of 11 normal subjects, 28.7 +- 7.2 mU/ml (P<0.0002). However, the Epo level in 31 polycythaemia vera (PV) patients, M = 21.9 +- 6.6 mU/ml, was not significantly different from normal (P = 0.006). Since previous studies with bioassay of heat-treated and concentrated plasma samples have shown a decreased serum-Epo level in PV, Epo levels were measured before and after heat treatment and concentration of samples from normals and polycythaemics. It was found that the levels of immunoreactive material increased after heat treatment and 40 times concentration in samples from normals and patients with secondary polycythaemias, but decreased in PV. We conclude that the Epo levels in serum in the low range measured by our and previous RIA:s probably are not true Epo levels but are partly due to an unspecific serum effect, that was removed by heat treatment.

  7. Radioimmunoassay of creatine kinase BB isoenzyme

    International Nuclear Information System (INIS)

    Geng Jianguo

    1988-01-01

    A radioimmunoassay of creatine kinase BB isoenzyme (CK-BB) was developed by using CK-BB purified from human brain. The CK-BB antiserum was raised by immunizing rabbite and 125 I-CK-BB iodinated with Bolton-Hunter reagent. The affinity constant was 3.0 x 10 9 mol/L. No cross reactions with creatine kinase MM isoenzyme and neuron-specific enolase were found. The measuring range was 3.5 x 10 -8 ∼ 1.2 x 10 -5 mmol/L, the average recovery rate 97.5%, with the inter and intrassay CV 3.1% and 12%, respectively. The average serum CK-BB concentration in 83 normal persons was 1.5 x 10 -7 +- 8.1 x 10 -8 mmol/L, quite different from the values of acute myocardial infarction (5.2 x 10 -6 +- 1.2 x 10 -4 mmol/L, n = 28) and cerebral vascular accident (8.4 x 10 -4 +- 5.0 x 10 -4 mmol/L, n = 10)

  8. Development of radioimmunoassay for prolactin binding protein

    Energy Technology Data Exchange (ETDEWEB)

    Raikar, R.S.; Sheth, A.R. (Institute for Research in Reproduction, Bombay (India))

    1982-01-01

    Using a homogenous prolactin binding protein (PBP) preparations from rat seminal vesicle secretion, a sensitive and specific radioimmunoassay (RIA) for PBP has been developed. The assay was highly specific and showed no cross-reaction with other protein hormones from various species. The antiserum had an affinity constant (Ka) of 2.66 x 10/sup 10/ M/sup -1/. The assay sensitivity was in the range of 0.5-1.0 ng of pure PBP per assay tube and the intra- and inter-assay coefficients of variations were 6-8% and 12-14.5% respectively. The overall recovery of PBP to the rat seminal vesicle secretion was 96.8%. Using this RIA, PBP levels in various biological fluids and reproductive tissues were measured. Azoospermic human semen contained significantly higher levels of PBP than normospermic semen. The seminal vesicle of rat exhibited the highest concentration of PBP. Administration of antiserum to PBP to mature male rats resulted in a significant reduction in the weight of ventral prostrate and serum prolactin levels were significantly elevated in these animals suggesting that the antibody raised against the PBP was capable of blocking prolactin receptors.

  9. Radioimmunoassay for human health in developing countries

    International Nuclear Information System (INIS)

    Piyasena, R.D.; Airey, P.L.; Ganatra, R.D.; Nofal, M.

    1989-01-01

    Since first introduced in the early 1960s, radioimmunoassay (RIA) has gained wide acceptance as an analytical method adopted by an increasing number of developing countries as an appropriate technology that can be managed within the capabilities of local infrastructures. An informed estimate would be that there are, at present, more than 500 hospitals, university, or other laboratories in the developing world engaged in RIA on some scale. In the developing world, RIA is used primarily for patient management, but research activity is also increasing as expertise and resources improve. The majority of patient samples processed are in relation to thyroid disorders. However, the technique also is used widely in the investigation of other endocrine conditions and public health problems. Some developing countries have gained the capability to perform radioisotopic microassays in areas of clinical and research importance such as steroid receptor quantification in breast tissue; diagnosis of bacterial and parasitic disorders; investigation of infertility and sterility; narcotic drug abuse; and organ transplantation. 1 fig

  10. A simple radioimmunoassay for plasma cortisol

    International Nuclear Information System (INIS)

    Seth, J.; Brown, L.M.

    1978-01-01

    A simple radioimmunoassay (RIA) for plasma cortisol is described which combines the advantages of (i) direct analysis of untreated plasma samples, (ii) use of solid-coupled anti-cortisol antibodies and (iii) use of a gamma-labelled radioligand. The reagents are relatively easily prepared and stable, and the analysis can be completed in 4 h. Inter-assay precision (C.V.) is 8-11%. Critical examination of specificity using high pressure liquid chromatography showed that 23-35% of the immunoassayable material in plasma was not cortisol. RIA results on samples collected under basal conditions were an average 40 nmol/l lower than fluorimetric results, while in insulin hypoglycaemia and synacthen (ACTH) stimulation tests, this difference increased to over 100 nmol/l. The RIA is technically more simple than fluorimetric, competitive-protein-binding, and many RIA methods, and can be used with advantage in the routine investigation of adrenocortical function. However, using the present antiserum, the RIA is not applicable to investigations on patients receiving metyrapone, nor in suspected cases of congenital adrenal hyperplasia. (Auth.)

  11. Steroid radioimmunoassays. The problems of blanks

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, Y; Hacker, R R; Ntunde, B; Smith, V G [Guelph Univ., Ontario (Canada). Dept. of Animal and Poultry Science

    1981-06-01

    An estrogen radioimmunoassay was used to study the problem of blanks in steroid assays. Negligible binding (1.5 percent) in the non-antibody tubes prevailed throughout the study. The assay was validated using accepted procedures. Both water and solvent blanks had estrogen concentrations of 7-9 pg/tube. However, neither water nor solvent blanks showed a dose-related response, indicating that they were 'real' blanks. Exogenous estradiol, when added to water and solvent in quantities less than the estimated blank, was not quantitatively recovered. However, exogenous estradiol added to the water solvent in quantities greater than the blank estimate was quantitatively recovered. The sensitivity of the reference standard curve was 6-10 pg/tube, approximately the same as the blank estimate. These results indicated that the estimates of water and solvent blanks were measures of the assay sensitivity. In such circumstances, it is suggested that blank estimates should not be subtracted from sample values. If the blank estimates are high, attention should be directed towards improving the sensitivity of the assay.

  12. Parathyroid hormone: radioimmunoassay and clinical interpretation

    International Nuclear Information System (INIS)

    Hawker, C.D.

    1975-01-01

    A radioimmunoassay for serum immunoreactive parathyroid hormone (iPTH), which has had widespread clinical use for five years, is described in detail. The iPTH results in large groups of patients are reported, and are discussed in relation to the specificity of the assay and in relation to other assays. The assay has excellent precision and is highly proficient in discrimination of groups of patients. Ninety-three percent of 412 patients with surgically proven primary hyperparathyroidism were confidently separated from normal subjects or patients with hypercalcemia owing to other causes, while 86 percent of 160 patients with chronic renal failure and secondary hyperparathyroidism had iPTH values more than 2 S.D. above the normal mean. Results in patients with ectopic hyperparathyroidism were lower than in primary hyperparathyroidism although these groups showed considerable overlap. The antiserum used in this assay for iPTH appears to be specific for the carboxy-terminal region of the secreted or intact form of PTH but recognizes predominantly the secreted form rather than carboxy-terminal fragments believed to be in the circulation. It does not recognize amino terminal fragments. The assay is useful in selective venous catheterization for preoperative localization of hyperfunctioning parathyroid tissue

  13. Elevations in the Fasting Serum Proinsulin–to–C-Peptide Ratio Precede the Onset of Type 1 Diabetes

    Science.gov (United States)

    Sims, Emily K.; Chaudhry, Zunaira; Watkins, Renecia; Syed, Farooq; Blum, Janice; Ouyang, Fangqian; Perkins, Susan M.; Mirmira, Raghavendra G.; Sosenko, Jay; DiMeglio, Linda A.

    2016-01-01

    OBJECTIVE We tested whether an elevation in the serum proinsulin–to–C-peptide ratio (PI:C), a biomarker of β-cell endoplasmic reticulum (ER) dysfunction, was associated with progression to type 1 diabetes. RESEARCH DESIGN AND METHODS Fasting total PI and C levels were measured in banked serum samples obtained from TrialNet Pathway to Prevention (PTP) participants, a cohort of autoantibody-positive relatives without diabetes of individuals with type 1 diabetes. Samples were obtained ∼12 months before diabetes onset from PTP progressors in whom diabetes developed (n = 60), and were compared with age-, sex-, and BMI-matched nonprogressors who remained normoglycemic (n = 58). PI:C ratios were calculated as molar ratios and were multiplied by 100% to obtain PI levels as a percentage of C levels. RESULTS Although absolute PI levels did not differ between groups, PI:C ratios were significantly increased in antibody-positive subjects in whom there was progression to diabetes compared with nonprogressors (median 1.81% vs. 1.17%, P = 0.03). The difference between groups was most pronounced in subjects who were ≤10 years old, where the median progressor PI:C ratio was nearly triple that of nonprogressors; 90.0% of subjects in this age group within the upper PI:C quartile progressed to the development of diabetes. Logistic regression analysis, adjusted for age and BMI, demonstrated increased odds of progression for higher natural log PI:C ratio values (odds ratio 1.44, 95% CI 1.02, 2.05). CONCLUSIONS These data suggest that β-cell ER dysfunction precedes type 1 diabetes onset, especially in younger children. Elevations in the serum PI:C ratio may have utility in predicting the onset of type 1 diabetes in the presymptomatic phase. PMID:27385327

  14. Elevations in the Fasting Serum Proinsulin-to-C-Peptide Ratio Precede the Onset of Type 1 Diabetes.

    Science.gov (United States)

    Sims, Emily K; Chaudhry, Zunaira; Watkins, Renecia; Syed, Farooq; Blum, Janice; Ouyang, Fangqian; Perkins, Susan M; Mirmira, Raghavendra G; Sosenko, Jay; DiMeglio, Linda A; Evans-Molina, Carmella

    2016-09-01

    We tested whether an elevation in the serum proinsulin-to-C-peptide ratio (PI:C), a biomarker of β-cell endoplasmic reticulum (ER) dysfunction, was associated with progression to type 1 diabetes. Fasting total PI and C levels were measured in banked serum samples obtained from TrialNet Pathway to Prevention (PTP) participants, a cohort of autoantibody-positive relatives without diabetes of individuals with type 1 diabetes. Samples were obtained ∼12 months before diabetes onset from PTP progressors in whom diabetes developed (n = 60), and were compared with age-, sex-, and BMI-matched nonprogressors who remained normoglycemic (n = 58). PI:C ratios were calculated as molar ratios and were multiplied by 100% to obtain PI levels as a percentage of C levels. Although absolute PI levels did not differ between groups, PI:C ratios were significantly increased in antibody-positive subjects in whom there was progression to diabetes compared with nonprogressors (median 1.81% vs. 1.17%, P = 0.03). The difference between groups was most pronounced in subjects who were ≤10 years old, where the median progressor PI:C ratio was nearly triple that of nonprogressors; 90.0% of subjects in this age group within the upper PI:C quartile progressed to the development of diabetes. Logistic regression analysis, adjusted for age and BMI, demonstrated increased odds of progression for higher natural log PI:C ratio values (odds ratio 1.44, 95% CI 1.02, 2.05). These data suggest that β-cell ER dysfunction precedes type 1 diabetes onset, especially in younger children. Elevations in the serum PI:C ratio may have utility in predicting the onset of type 1 diabetes in the presymptomatic phase. © 2016 by the American Diabetes Association.

  15. Home urine C-peptide creatinine ratio (UCPCR) testing can identify type 2 and MODY in pediatric diabetes.

    Science.gov (United States)

    Besser, Rachel E J; Shields, Beverley M; Hammersley, Suzanne E; Colclough, Kevin; McDonald, Timothy J; Gray, Zoe; Heywood, James J N; Barrett, Timothy G; Hattersley, Andrew T

    2013-05-01

    Making the correct diabetes diagnosis in children is crucial for lifelong management. Type 2 diabetes and maturity onset diabetes of the young (MODY) are seen in the pediatric setting, and can be difficult to discriminate from type 1 diabetes. Postprandial urinary C-peptide creatinine ratio (UCPCR) is a non-invasive measure of endogenous insulin secretion that has not been tested as a diagnostic tool in children or in patients with diabetes duration MODY and type 2 in pediatric diabetes. Two-hour postprandial UCPCR was measured in 264 patients aged MODY, n = 63). Receiver operating characteristic curves were used to identify the optimal UCPCR cutoff for discriminating diabetes subtypes. UCPCR was lower in type 1 diabetes [0.05 (MODY [3.51 (2.37-5.32) nmol/mmol, p MODY (p = 0.25), so patients were combined for subsequent analyses. After 2-yr duration, UCPCR ≥ 0.7 nmol/mmol has 100% sensitivity [95% confidence interval (CI): 92-100] and 97% specificity (95% CI: 91-99) for identifying non-type 1 (MODY + type 2 diabetes) from type 1 diabetes [area under the curve (AUC) 0.997]. UCPCR was poor at discriminating MODY from type 2 diabetes (AUC 0.57). UCPCR testing can be used in diabetes duration greater than 2 yr to identify pediatric patients with non-type 1 diabetes. UCPCR testing is a practical non-invasive method for use in the pediatric outpatient setting. © 2013 John Wiley & Sons A/S.

  16. Nutritional factors and preservation of C-peptide in youth with recently diagnosed type 1 diabetes: SEARCH Nutrition Ancillary Study.

    Science.gov (United States)

    Mayer-Davis, Elizabeth J; Dabelea, Dana; Crandell, Jamie L; Crume, Tessa; D'Agostino, Ralph B; Dolan, Lawrence; King, Irena B; Lawrence, Jean M; Norris, Jill M; Pihoker, Catherine; The, Natalie

    2013-07-01

    To test the novel hypothesis that nutritional factors previously associated with type 1 diabetes etiology or with insulin secretion are prospectively associated with fasting C-peptide (FCP) concentration among youth recently diagnosed with type 1 diabetes. Included were 1,316 youth with autoantibody-positive type 1 diabetes who participated in the SEARCH for Diabetes in Youth study (baseline disease duration, 9.9 months; SD, 6.3). Nutritional exposures included breastfeeding and age at introduction of complementary foods, baseline plasma long-chain omega-3 fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), vitamin D, vitamin E, and, from a baseline food frequency questionnaire, estimated intake of the branched-chain amino acid leucine and total carbohydrate. Multiple linear regression models were conducted to relate each nutritional factor to baseline FCP adjusted for demographics, disease-related factors, and other confounders. Prospective analyses included the subset of participants with preserved β-cell function at baseline (baseline FCP ≥0.23 ng/mL) with additional adjustment for baseline FCP and time (mean follow-up, 24.3 months; SD, 8.2; n = 656). FCP concentration was analyzed as log(FCP). In adjusted prospective analyses, baseline EPA (P = 0.02), EPA plus DHA (P = 0.03), and leucine (P = 0.03) were each associated positively and significantly with FCP at follow-up. Vitamin D was unexpectedly inversely associated with FCP (P = 0.002). Increased intake of branched-chain amino acids and long-chain omega-3 fatty acids may support preservation of β-cell function. This represents a new direction for research to improve prognosis for type 1 diabetes.

  17. Immunodiagnosis of opportunistic mycoses: detection of fungal antigenemia by radioimmunoassays in systemic candidiasis and aspergillosis

    International Nuclear Information System (INIS)

    Weiner, M.H.

    1980-01-01

    The authors have developed radioimmunoassays to the Candida carbohydrate, mannan, and to an Aspergillus cell wall carbohydrate. They evaluate these radioimmunoassays with sera from rabbit models of disseminated mycoses, and further evaluate the radioimmunoassays for their diagnostic usefulness in a panel of patient sera. (Auth.)

  18. Dessert Formulation Using Sucralose and Dextrin Affects Favorably Postprandial Response to Glucose, Insulin, and C-Peptide in Type 2 Diabetic Patients

    OpenAIRE

    Argyri, Konstantina; Sotiropoulos, Alexios; Psarou, Eirini; Papazafiropoulou, Athanasia; Zampelas, Antonios; Kapsokefalou, Maria

    2013-01-01

    BACKGROUND: Dessert compositions may conform to diabetic diet when it contains low sugar or artificial sweetener to replace sugar. However, it is still questionable whether glycemic control in type 2 diabetes patients is improved by the use of diet-conforming dessert compositions. OBJECTIVE: To compare, in type 2 diabetes patients, the glycemic, insulin, and C-peptide responses to seven modified dessert compositions for diabetics (D-dessert) with the response to seven similar desserts of non-...

  19. Estimation of antibodies to human cytomegalovirus by immunofluorescence and radioimmunoassay

    International Nuclear Information System (INIS)

    Jankowski, M.; Gut, W.; Nawrocka, E.

    1980-01-01

    The 125 I labelled IgG fraction against rabbit IgG of goat origin was employed for the detection of CMV IgG and IgM antibodies in the double indirect radioimmunoassay. The results were compared with those obtained in complement fixation, indirect immunofluorescence and anti-complement immunofluorescence tests. The application of labelled anti-fc antisera, instead of antisera against whole IgG in the tests for detection of specific CMV IgG antibody resulted in increased sensitivity of radioimmunoassay and reduction of non-specific cytoplasmatic reactions in preparations stained by indirect immunofluorescence. The absorption of sera with protein A rich staphylococci and aggregates to immunoglobulin eliminated unwanted secondary IgM staining caused by rheumatoid factors both in indirect immunofluorescence and radioimmunoassay tests for CMV antibodies. (author)

  20. Radioimmunoassay for pantothenic acid in blood and other tissues

    International Nuclear Information System (INIS)

    Wyse, B.W.; Wittwer, C.; Hansen, R.G.

    1979-01-01

    We described a radioimmunoassay for pantothenic acid in biological tissues. D-Pantothenic acid was conjugated with bovine serum albumin by use of a bromoacetyl derivative of pantothenic acid, and antibody to this antigen was raised by injecting it into the foot pads of rabbits. For the radioimmunoassay, a 100-fold dilution of the resulting antiserum was incubated with radiolabeled panthothentic acid. The antibodies were precipitated and dissolved, and the radioactivity of the solution was measured in a liquid scintillation counter. Between 5 and 125 ng of pantothenic acid can be detected in 75 μL of tissue extract. Validation included recovery and precision studies, parallelism with tissue extracts, and competitive binding studies. Results of the radioimmunoassay and those of microbiological assay with use of Lactobacillus plantarum correlated well