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Sample records for two-site sandwich radioimmunoassay

  1. 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.)

  2. Kinetics of two-site immunoradiometric ('sandwich') assays

    International Nuclear Information System (INIS)

    Rodbard, D.; Feldman, Y.; Jaffe, M.L.; Miles, L.E.M.

    1978-01-01

    The mathematical model of the ideal two-site IRMA developed in the accompanying report, which assumes that both the first (solid phase) and second (labeled) antisera are 'homogeneous', fails to provide an explanation for the frequent occurrence of a paradoxical fall in the dose-response curve in the high-dose region ('high-dose hook effect'). Accordingly, the model has been extended in an attempt to provide a theoretical basis for these phenomena. Two mechanisms were considered: (A) heterogeneity of the first antiserum (which is bound to the solid phase), i.e. presence of two or more classes of sites with moderately to widely differing affinity constants; and (B) incomplete washing of the solid phase after the first reaction. This leads to an expanded system of five differential equations, five equations for conservation of mass, and fourteen rate constants. In the presence of a heterogeneous first antiserum, a high dose 'hook effect' will occur. Rapid dissociation of the ligand from the low affinity class of sites during the second 'wash' procedure will accentuate this effect. Thus, heterogeneity of binding sites is a sufficient explanation for the high-dose hook effect and is a likely mechanism in practice, since the antisera which are coupled to the solid phase have usually not been fractionated. The present studies also show that, even if dealing with homogeneous first antibody, one may still observe a high-dose hook effect if washing is incomplete after the first incubation with the antigen. Using computer simulation studies, factors affecting the magnitude of the 'high-dose hook effect' have been explored. (author)

  3. Immunoassay of blood spot TSH; development of a rapid two-site immunoradiometric assay and comparison with radioimmunoassay as a screening method for neonatal hypothyroidism

    International Nuclear Information System (INIS)

    Sutherland, R.M.; Ratcliffe, J.G.; Chapman, R.S.

    1982-01-01

    The development of a two-site immunoradiometric assay (IRMA) for thyrotropin (TSH) eluted from dried blood filter paper discs is described and compared with a conventional TSH radioimmunoassay (RIA) as a screening procedure for neonatal hypothyroidism. The two-site IRMA involves a primary incubation of excess labelled TSH antibody and the blood disc for 16-18 h at pH 8 and a secondary 3 h incubation under agitation, with solid phase TSH antibody. Bound and free fractions are separated by a semi-automated washing procedure. It is concluded that the two-site TSH IRMA has advantages over conventional RIA in speed, sensitivity, precision and ruggedness and can be recommended as an efficient screening procedure for neonatal hypothyroidism. (Auth.)

  4. A new solid-phase sandwich radioimmunoassay and its application to the detection of snake venom

    International Nuclear Information System (INIS)

    Coulter, A.R.; Cox, J.C.; Sutherland, S.K.; Waddel, C.J.

    1978-01-01

    A solid-phase sandwich radioimmunoassay is described which can be used for the detection and quantitative estimation of crude snake venom and a snake neurotoxin in clinical and experimental situations. Rabbit IgG antivenom or antineurotoxin, covalently coupled to a solid phase (CH-Sepharose 4B) is incubated with sample of unknown venom concentration. Venom bound by the solid-phase antibody is detected by reaction with 125 I-labelled rabbit IgG antivenom or antineurotoxin ([ 125 I]IgG). The resultant count, T, is the total (specific and non-specific) uptake of [ 125 I]IgG. Non-specific binding N, is similarly determined, but with normal rabbit IgG antivenom or antineurotoxin ([ 125 I]IgG). The resultant count, T, is the total (specific and non-specific) uptake of [ 125 I]IgG. Non-specific binding N, is similarly determined, but with normal rabbit IgG bound to the solid phase. A T:N value greater than 1.8 for human serum or urine indicates the presence of venom in a sample (P>0.95). Positive samples are assayed at several dilutions and the venom present estimated from the specific count (T-N). Levels of 0.4 ng/ml of crude tiger snake venom (TSV) and 0.1 ng/ml of neurotoxin can be reliably detected by this procedure. (Auth.)

  5. A four-step sandwich radioimmunoassay for direct selection of monoclonal antibodies to allergen molecules

    International Nuclear Information System (INIS)

    Ley, V.; Corbi, A.L.; Sanchez-Madrid, F.; Carreira, J.C.

    1985-01-01

    A 4-step radioimmunoassay has been devised for direct identification of monoclonal antibodies (MAb) directed to IgE-binding molecules. Polyvinyl chloride wells coated with purified anti-mouse kappa chain MAb (187-1) were successively incubated with: (1) MAb-containing hybridoma supernatants, (2) allergen extract, (3) allergic patients' serum pool, and (4) 125 I-labeled anti-human IgE antiserum, to detect MAb-allergen-IgE complexes. MAb to allergens from Parietaria judaica pollen and Dermatophagoides mites have been selected with this screening procedure. The affinity-purified allergen molecules competed the binding of IgE to allergen extracts coated to paper discs in a RAST inhibition assay, confirming the anti-allergen specificity of the selected MAb. This screening method is sensitive enough to allow detection of MAb directed to poorly represented allergens. (Auth.)

  6. 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)

  7. 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

  8. 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.)

  9. Sandwich Courses

    Science.gov (United States)

    Overy, B. B.

    1972-01-01

    A look at the responsibilities that a college takes on in offering sandwich courses, i.e., courses (primarily technical) which alternate academic study with field experience. A primary problem is finding suitable industrial training situations. Greater involvement of small firms and specialized industries is one answer. (Author/JB)

  10. 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.)

  11. 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.)

  12. Radioimmunoassay of norandrosterone

    International Nuclear Information System (INIS)

    Hampl, R.; Starka, L.; Putz, Z.; Protiva, J.

    1983-01-01

    A simple radioimmunoassay of the main nortestosterone metabolite, 3α-hydroxy-5α-estran-17-one (norandrosterone) is described and evaluated. The method employs 3 H-labelled ligand prepared from nortestosterone by three-step synthesis and rabbit antiserum against norandrosterone-17-carboxymethyloxime bovine serumalbumin. (author)

  13. 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.)

  14. 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

  15. 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)

  16. Radioimmunoassay of buprenorphine

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, A.J.; Lloyd-Jones, J.G.; Rance, M.J.; Flockhart, I.R.; Dockray, G.J.; Bennett, M.R.D.

    1980-01-01

    Antisera to buprenorphine were obtained in rabbits immunised with 3-0-carboxymethylbuprenorphine and N-hemisuccinyl-norbuprenorphine conjugated to bovine serum albumin. Using the latter antiserum and tritium labelled buprenorphine a radioimmunoassay having good accuracy and precision was developed for concentrations as low as 50 picograms in 1 ml of plasma. The N-hemisuccinyl antiserum crossreacted with norbuprenorphine, and the 3-0-glucuronide conjugate with the 3-0-carboxy-methyl antiserum. Cross-reactivity of both antisera to other pharmacologically related compounds was negligible. The assay was employed to determine plasma buprenorphine concentration following its parenteral administration to dog and man.

  17. 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)

  18. 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

  19. 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.)

  20. Radioimmunoassay of erythropoietin

    International Nuclear Information System (INIS)

    Goldwasser, E.; Sherwood, J.B.

    1981-01-01

    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. (U.K.)

  1. 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.)

  2. Radioimmunoassay for serum paraquat

    International Nuclear Information System (INIS)

    Fatori, D.; Hunter, W.M.

    1980-01-01

    Two variants of a radioimmunoassay for the bipyridylium herbicide Paraquat are described. Both employ antiserum raised to Paraquat-BSA which has been covalently linked to particulate solid-phase support media. The rapid assay for clinical use employs a [ 3 H] Paraquat tracer, requires no agitation and yields results in the range 10-2500 ng/ml serum in 20 min from receipt of sample. The more sensitive assay, designed for research purposes, employs a 125 iodinated tracer, requires 2 h continuous agitation but can detect Paraquat at 0.1 ng/ml in simple aqueous solution or 0.25 ng/ml serum. Results from rapid clinical assay agree well with the existing colorimetric method. (Auth.)

  3. 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)

  4. 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.)

  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. 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.)

  7. Calcitonin radioimmunoassay: clinical application

    International Nuclear Information System (INIS)

    Raue, F.; Minne, H.; Streibl, W.; Ziegler, R.; Ulm Univ.

    1977-01-01

    A radioimmunoassay for human Calcitonin (hCT) was established: antisera were produced by immunizing goats with synthetic hCT; 7.5 μg hCT were labelled with 1 mCi 125 J; hCT of different quantities in the range between 0.1 to 20 ng/ml served as standard. Separation of free from antibody bound tracer was done using the charcoal procedure. - This RIA-system was sensitive to determine 0.1 ng/ml; the normal range lying below 0.5 ng/ml. This assay was used to study the following clinical problems: 1) in 31 patients, with a thyroid tumor, diagnosis of calcitonin producing medullary thyroid carcinoma was proven. Serum calcitonin of these patients were lying between 1.7 and 120 ng/ml. Clinical signs of this disease are nonspecific, so CT determination is of importance for early diagnosis and control of therapy. In patients with a high tumor risk pentapastrin stimulation of the C-cells reveals calcitonin secretion above normal, if a medullary thyroid carcinoma is present. 2) two patients with pheochromocytoma showed elevated levels of CT before operation; after removal of the tumor serum CT was normalized. Extracts of the adreno-medullary tumor revealed immunoreactive CT corresponding to 4 and 1 ng/ml wet weight. - 3) CT is used for therapy of Paget's disease of the bone, so control of antibody development in the patients is necessary. In 25 patients with Paget's disease no antibody production against the injected hormone was evident. (orig.) [de

  8. Radioimmunoassay for rhesus monkey gonadotropins

    International Nuclear Information System (INIS)

    Faiman, C.; Stearns, E.L.; Winter, J.S.D.; Reyes, F.I.; Hobson, W.C.

    1975-01-01

    Heterologous double-antibody radioimmunoassay methods are described for the measurement of circulating levels of rhesus monkey (Macaca mulatta) FSH and LH; the latter assay is also applicable to rhesus chorionic gonadotropin (CG) estimations. The FSH assay utilizes purified rat FSH for trace, either of two anti-human FSH antisera and a semipurified rhesus pituitary standard. The LH assay utilizes purified ovine LH for trace, an anti-human CG antiserum and the same rhesus pituitary standard. The use of these systems obviates the necessity of purifying rhesus gonadotropins which are required for the development of homologous radioimmunoassay systems. (U.S.)

  9. Radioimmunoassay of Human Chorionic Gonodotropin

    International Nuclear Information System (INIS)

    Majali, M.A.; Shah, K.B.; Mani, R.S.

    1981-01-01

    A rapid and sensitive radioimmunoassay has been developed for the measurement of Human Chorionic Gonadotropin (HCG) in serum. Human chorionic gonadotropin has been labelled with 125 I to attain a specific activity between 80-120 μCi/μg. Aqueous dioxane (74 vol.%) has been employed to separate the bound and freehormone in the radioimmunoassay. The sensitivity of this technique has been found to be approximately 1.5 mIU/ml of HCG. The intra assay variation has been found to be less than 5% and inter assay variation has been found to be less than 12%. (author)

  10. 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

  11. SIGNS The sandwich sign

    African Journals Online (AJOL)

    appearance of necrosis or rim enhancement, as typically seen in TB.1. This theory was refuted by a single study in 2008 by Lien et al. which documents biopsy-proven non-lymphomatous causes of the sandwich sign.4 The authors reported that in addition to lymphoma being the most common cause of the sandwich sign, ...

  12. 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

  13. 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

  14. Homologous radioimmunoassay of human prolactin

    International Nuclear Information System (INIS)

    Felixberger, F.X.

    1980-01-01

    Gelfiltration on Sephadex G-75 showed a heterogenity of prolactin in serum of patients with prolactinoma and in culture medium of a prolactinoma. Serum of patients with prolactinoma and culture medium of a prolactinoma were examined as possible sources of prolactin by gel filtration and ion exchange chromatography. Polyacrylamide electrophoresis revealed both preparations as contaminated by other proteins. Nevertheless prolactin isolated form culture medium of a prolactinoma is good enough as a tracer in our radioimmunoassay because contaminating proteins in this preparation do not inferfere in our system. An hPRL antiserum created in a rabbit against a crude fraction of human serum of a patient with prolactinoma was tested by titration, saturation studies, and ion exchange chromatography. In comparison with lactoperoxidase-iodinated prolactin Chloramine T iodinated prolactin showed higher loss of immunochemical properity, however higher specific activity. Specifity and precision in our radioimmunoassay system were described and the conditions of optimal sensitivity in our assay were evaluated. (orig.) [de

  15. Homologous radioimmunoassay for human prolactin

    International Nuclear Information System (INIS)

    Reuter, A.M.; Kennes, F.; Gevaert, Y.; Franchimont, P.

    1976-01-01

    Although thee are descriptions of a range of radioimmunoassays for human prolactin in various biological fluids, only one of these is an homologous assay using human prolactin as the reference standard and tracer as well and an anti-human prolactin antiserum (Sinha, Y.N., Selby, F.W.; Lewis, U.; and Vanderlaan, W.P., 1973, J. Clin. Endocr., Vol. 36, 509). A homologous radioimmunoassay using human putuitary prolactin has been developed. The separation method is based on the double antibody solid phase system. Cross reactivity with human growth hormone (GH), placental lactogen (HPL), the pituitary protein hormones and prolactins of various species were studied as were values found in normal subjects in basal conditions and after a TRH injection. (author)

  16. Development and application of radioimmunoassay and enzyme immunoassays in microbiological and immunological diagnosis. 4

    International Nuclear Information System (INIS)

    Struy, H.; Horeschi, G.; Wolffgang, H.; Morenz, J.

    1982-01-01

    Indirect solid phase radioimmunoassays and enzyme immunoassays were developed for the quantitative determination of low concentrations of IgG, IgA, IgM, and IgE. PVC blister and microtiterplates of polystyrene with adsorptively bound purified immunoglobulins were used as carrier. The determination of the immunoglobulins was accomplished with a uniform system of indicators, which consists of class-specific antihuman immunoglobulin sera from rabbits and of labelled ( 125 I and horseradish peroxydase, resp.) antirabbitglobulin from sheep. The developped competitive radioimmuno- and enzyme immunoassays allows the determination of concentrations of classes of immunoglobulins down to nearly 1 ng/ml, and the indirect sandwich solid phase radioimmunoassay determinations of IgE down to about 1 IU/ml. The values of IgG determined in liquors and those of IgE found in sera correspond very well to values which were measured with commercial kits. (author)

  17. 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

  18. 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

  19. 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

  20. 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)

  1. Predicting safe sandwich production

    DEFF Research Database (Denmark)

    Birk, Tina; Duan, Zhi; Møller, Cleide Oliveira de Almeida

    2014-01-01

    Time and temperature control is crucial to avoid growth of pathogens during production and serving of cold ready-to-eat meals. The Danish guidelines state that chilled foods, such as sandwiches, should not be outside the cold chain for more than 3 hours including the time for preparation and serv......Time and temperature control is crucial to avoid growth of pathogens during production and serving of cold ready-to-eat meals. The Danish guidelines state that chilled foods, such as sandwiches, should not be outside the cold chain for more than 3 hours including the time for preparation...... and serving. However, Danish sandwich producing companies find it challenging to comply with this and have expressed a need for more flexibility. The Danish guidelines do allow for a prolongation of the acceptable time outside the cold chain, if the safety of the specific production can be documented....... There is, therefore, room for developing targeted tools for evaluating the time-temperature scenarios in sandwich production. This study describes a decision support tool developed to offer the producers more flexibility. Based on time/temperature measurements obtained during preparation combined...

  2. Salads, Sandwiches and Desserts.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on salads, sandwiches, and desserts is designed to provide Marine food service personnel with a general background in the proper techniques for the preparation of these items. Introductory materials include specific information for MCI students and a…

  3. 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.)

  4. Radioimmunoassay of bovine growth hormone

    International Nuclear Information System (INIS)

    Dvorak, P.; Becka, S.; Krejci, P.; Chrpova, M.

    1978-01-01

    A radioimmunological method for quantitative determination of bovine growth hormone in blood plasma or serum for routine use was worked out. The antibody is also suitable for radioimmunoassay of bovine growth hormone. The chloramin T and lactoperoxidase methods were used. Standard b-STH isolated by one of the authors was labelled with I-125(Na 125 I, carrier free, Amersham). The I-125-hormone was separated on Sephadex G-50 or G-100 and stored in 0.05M phosphate pH 7.5 with 1% of human serum albumine at 25 deg C. The method was checked on 2500 samples. Rabbit antiserum to b-STH was prepared in sufficient amount to serve also for other laboratories interested in the method. (author)

  5. The radioimmunoassay of steroid glucuronides

    International Nuclear Information System (INIS)

    Chaudhri, B.

    1980-07-01

    A radioimmunoassay method for steroid glucuronides in which the second carboxylated group has been introduced into the steroid structure and used to attach the hapten to the protein. The unequivocal attachment through the second group, rather than through the glucuronide is achieved by leaving the glucuronide protected as its triacetyl methyl-ester (g.a.m.e.) until after the hapten has been coupled to the protein. The hapten, immunogens and antisera to costrone-3-glucuronide have been prepared using a 17-carboxymethyloxime bridge. The antisera raised to these immunogens have been characterised for their ability to discriminate between the free steroid and the steroid glucuronide, and evaluated for use in immunoassay. (author)

  6. Radioimmunoassay for chlorpromazine in plasma

    International Nuclear Information System (INIS)

    Midha, K.K.; Loo, J.C.K.; Hubbard, J.W.; Rowe, M.L.; McGilveray, I.J.

    1979-01-01

    A radioimmunoassay for chlorpromazine in plasma is described. The antiserum was obtained by immunizing rabbits with a conjugate of bovine serum albumin and N-(2-carboxyethyl)desmethylchlorpromazine. It is specific for chlorpromazine and its minor active metabolite, N-desmethylchlorpromazine. Other known active or inactive chlorpromazine metabolites and other psychotropic drugs tested do not cross react with the antiserum. Less than 34 pg of the drug can be detected in 200 μL of plasma. As many as 100 samples can be processed in a day by one technician. Concentrations of chlorpromazine can be measured in 200-μL samples of plasma collected as late as 48 h after a single oral 25-mg dose

  7. 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)

  8. Sandwich or sweets?

    DEFF Research Database (Denmark)

    Kraus, Alexandra; Piqueras-Fiszman, Betina

    2016-01-01

    Desire, purchase, and consumption of fast-moving consumer goods often follow actual motivational states instead of habitual preferences. This has led to an increasing interest within health sciences to investigate the causes for irrational eating behaviours among consumers, particularly...... foods (sandwich and sweets) on visual analogue scales, as well as implicit approach–avoidance tendencies and implicit positive–negative associations with two variants of the recoding-free Implicit Association Tests (IAT-RFs). At first, all participants (N = 108) unwrapped, smelled, and explicitly judged...... the two foods, then all watched a video clip (during which half of the participants were allowed to eat the sandwich but not the sweets), and finally they all performed the two indirect measurements. Thus, desire for the foods was experimentally manipulated between participants. We hypothesized...

  9. 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

  10. The radioimmunoassay of steroid glucuronides

    International Nuclear Information System (INIS)

    Chaudhri, R.

    1980-07-01

    A modified radioimmunoassay for steroid glucuronides is described. A second carboxylated group is introduced into the steroid structure and used to attach the hapten to the protein. The unequivocal attachment through the second group, rather than through the glucuronide is achieved by leaving the glucuronide protected as its triacetyl methylester until after the hapten has been coupled to the protein. Subsequently, the glucuronide can be exposed by mild alkaline hydrolysis or alternatively, the protected immunogen can be injected into the rabbits, leaving the animals to deprotect the hapten. The hapten, immunogens and antisera to oestrone-3-glucuronide have been prepared using a 17-carboxymethyloxime bridge. The hapten, immunogen and antisera to pregnanediol-3 α - glucuronide have also been prepared using a 6 β - hemisuccinoxy bridge. A study has been made of the reactive properties of the 6 β-hydroxyl group and its effect on the stereo-specificity of reduction of 4-ene and the 3-oxo group and on the reactivity of the 3 α-hydroxyl group. The antisera raised to these immunogens have been characterised for their ability to discriminate between the free steroid and the steroid glucuronide, and evaluated for use in immunoassay. (author)

  11. 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)

  12. 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)

  13. 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

  14. Steroid derivatives and their use in radioimmunoassays

    International Nuclear Information System (INIS)

    Varma, R.K.; Chao, S.T.

    1983-01-01

    Radioimmunoassay techniques have been used to determine the concentration in body fluids of various endogenous and exogenous steroids. In the development of radioimmunoassays for the various steroids, the preparation of an antigen labelled with iodine-125 is of primary concern. The chemical structure of steroids is such that it is generally not possible to radioiodinate them directly. It is necessary to utilize as a precursor of the radiolabeled antigen a derivative of the steroid to be assayed which can be readily iodinatd. The process by which steroids are chosen and structurally modified is given

  15. Radioimmunoassay for C-peptide and proinsulin

    International Nuclear Information System (INIS)

    Heding, L.G.

    1977-01-01

    Proinsulin, the biosynthetic precursor of insulin, was discovered by Steiner et al. (1967) and shown to be converted to insulin and C-peptide in the β-cell. The first part of this paper deals with aspects of the radioimmunoassay for C-peptide with special emphasis on the development and the sources of errors encountered in our laboratory (Heding, 1975; Naithani et al., 1975). The second part deals with the many problems involved in the determination of human proinsulin and describes a direct and specific radioimmunoassay developed for measuring proinsulin in serum with a detection limit of less than 0.01 pmol/ml. (Auth.)

  16. 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

  17. Determination of serum IgD radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. 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

  19. Development of Aircraft Sandwich Parts

    Directory of Open Access Journals (Sweden)

    J. Křena

    2000-01-01

    Full Text Available The presented paper shows the design and development process of sandwich parts. A spoiler plate and a main landing gear door are developed. Sandwich parts are made of C/E composite facings and a foam core. FE models have been used for optimization of structures. Emphasis has been placed on deformations of parts under a few load cases. Experimental tests have been used for a verification of structure parts loaded by concentrated forces.

  20. Radioimmunoassay for platelet activation specific protein GMP-140 on the platelet surface and in plasma

    International Nuclear Information System (INIS)

    Wu Guoxin; Li Jianyong; Ruan Changgeng

    1991-08-01

    Using monoclonal antibody (McAb) SZ-51 which is specific for an alpha-granule membrane protein (GMP-140) on the surface of human activated platelets, the platelet GMP-140 expression in fixed whole blood was measured by direct radioimmunoassay and GMP-140 microparticles in plasma was measured by sandwich method. The GMP-140 molecules per platelet or milliliter (mL) were calculated for the following subjects; acute myocardial infarction; cerebro thrombosis; diabetic mellitus; asthma attack; epidemic hemorrhagic fever etc.. By comparing with the concentration of thromboxane B 2 (TXB 2 ) and von Willebrand factor (vWF) in plasma, it is confirmed that the measurement of GMP-140 molecules is better than that of TXB 2 and vWF. It is a sensitive and specific method for evaluating the platelet activation degree in vivo. The establishment of this method will be useful to diagnosing the thrombotic disorders and studying the pathogenesis of some other diseases

  1. Radioimmunoassay of parathormone in human blood serum

    International Nuclear Information System (INIS)

    Leicht, E.

    1982-01-01

    A radioimmunoassay for immune reactive PTH in human blood serum has been developed and optimized. The method described is capable of largely safely discriminating increased PTH concentrations from normal values. For the group of patients suffering from hypoparathyroidism, the PTH values in the blood serum have been found to be generally lower, but quite an overlapping of lower values and values at the lower normal limit has been stated at the same time. Subsequent to an oral administration of phosphate in an acute experiment, so following a calcium-deficient diet taken over 24 hours, an increase in immune reactive PTH in the serum could be detected. The part of this thesis dealing with the method of treatment thoroughly discussed the various steps of optimization of the assay on the basis of extensive experimental data collected by the author. It presents a detailed assessment of current knowledge on, efficiency of and problems involved in PTH determination by radioimmunoassay. (orig./MG) [de

  2. Radioimmunoassay of deoxynivalenol in wheat and corn

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y.C.; Zhang, G.S.; Chu, F.S.

    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. 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

  4. 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

  5. Radioimmunoassay of peptide hormones using polyethyleneglycol, 2

    International Nuclear Information System (INIS)

    Ito, Yoshinori; Kikuchi, Akira; Inabe, Seijiro; Yabuuchi, Shinji; Kihara, Akira

    1975-01-01

    The radioimmunoassay (RIA) of glucagon was performed using 125 I in combination with polyethyleneglycol (PEG). In order to define the concentration of glucagon, the reaction time, the temperature and separation of F/B, the effects of the addition of various amounts of serum were studied. This method was found to be applicable, because of its reliability, simplicity, economy, and the shortness of the second reaction time. (Namekawa, K.)

  6. 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)

  7. 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.)

  8. 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

  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. A radioimmunoassay for urinary and serum dexamethasone

    International Nuclear Information System (INIS)

    Gilliland, J.M.; Morris, H.A.

    1986-01-01

    A radioimmunoassay suitable for measuring dexamethasone concentrations in serum and urine specimens following the low dose dexamethasone suppression test (0.25-1.0 mg dexamethasone) is reported. The assay has a sensitivity of 0.26 nmol/L, a between-assay coefficient of variation (CV) for dexamethasone concentrations between 1.15 and 15.40 nmol/L ranging from 11.7 - 5.5% and recoveries of 91 - 103%. (author)

  11. 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.

  12. Structural and failure mechanics of sandwich composites

    CERN Document Server

    Carlsson, LA; Carlsson, Leif A

    2011-01-01

    Focusing on important deformation and failure modes of sandwich structures, this volume describes the mechanics behind fracture processes. The text also reviews test methods developed for the cr, structural integrity, and failure mechanisms of sandwich structures.

  13. The “Sandwich Therapy”

    Science.gov (United States)

    Zeng, Ang; Song, Kexin; Zhang, Mingzi; Men, Quancang; Wang, Youbin; Zhu, Lin; Liu, Zhifei

    2017-01-01

    Background Keloid therapy remains a great challenge for plastic surgeons, especially when the defect cannot be closed primarily, necessitating tissue transplantation. Here, we introduce a new treatment modality, called the sandwich therapy, for presternal keloids; the sandwich therapy incorporates preradiotherapy, superficial circumflex iliac artery perforator (SCIP) flap transplantation, and postradiotherapy. Methods From December 2012 to October 2013, 12 patients received the “sandwich therapy.” For the protocol, all patients went through 5 days of specific events: the precut procedure, preradiotherapy, resection and SCIP flap transplantation, donor site radiotherapy, and final presternal radiotherapy. Results All the flaps survived completely. No complication was observed during the perioperative period. With a mean follow-up of 12 months, only 1 case was reported with an incisional hypertrophic scar. In all patients, the main discomfort complaints were resolved postoperatively. Conclusions A low-tension or without-tension closure could be achieved with SCIP flap transplantation. The perioperative radiotherapy could further lower the risk of keloid recurrence. The sandwich therapy provides a new surgical approach to presternal keloid treatment. PMID:28758907

  14. Wire and Packing Tape Sandwiches

    Science.gov (United States)

    Rabinowitz, Sandy

    2009-01-01

    In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

  15. 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

  16. 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

  17. 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.

  18. 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

  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 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

  1. 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)

  2. 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

  3. Radioimmunoassay of digoxigenin glycosides in Digitalis lanata

    International Nuclear Information System (INIS)

    Lehtola, T.; Hiltunen, R.; Schantz, M. v.; Huhtikangas, A.

    1981-01-01

    Radioimmunoassay (RIA) has been used in the analysis of digoxigenin glycoside contents of crude ethanolic extracts prepared from fresh leaf samples of Digitalis lanata EHRH. The commercial antidigoxin antiserum used in the assay was highly specific against the digoxigenin aglycone. Steroid derivatives with only slight structural differences from digoxigenin remained practically unassayed. The method is highly sensitive, and excellent values for accuracy, precision and correlation were obtained. Digoxigenin glycoside levels of second-year D. lanata leaves were found to be considerably higher than those of first-year leaves. (orig.)

  4. Two-Site Comparison of Transpiration by Larrea Tridentata

    Science.gov (United States)

    Cavanaugh, M. L.; Kurc, S. A.; Scott, R. L.; Bryant, R. B.

    2008-12-01

    As a result of landscape changes within the desert southwestern U.S. such as increased grazing, reduced wildfire frequency, and changes in atmospheric conditions, the native creosotebush (Larrea tridentata) has encroached upon historically grass-dominated ecosystems, expanding in range and land cover density. To understand how creosotebush influences the water budget of ecosystems, heat balance sap flow sensors were employed on creosotebush stems at both the Santa Rita Experimental Range (SRER) and Walnut Gulch Experimental Watershed (WGEW). Additionally, both sites are equipped with eddy covariance towers, associated micrometeorological measurements, and profiles of water content reflectometers for soil moisture. The differences found between the two sites, including soil type and precipitation regime, are the basis of the following hypotheses. Firstly, we hypothesize that we will not see transpiration (T) responses following storms less than 5 mm at both sites. Secondly, we hypothesize that at both sites we will see a lagged response of T to large precipitation events, with evaporation being the dominate component in the partitioning of evapotranspiration (ET) for the first two days. Thirdly, we hypothesize that the ratio of plant transpiration to total evapotranspiration (T/ET) will be less at SRER due to the larger amount of bare soil exposed at this site. In this study, we show data from one summer at both sites and show how these relate to different precipitation events and soil moisture reservoirs.

  5. Supervised and unsupervised learning with two sites of synaptic integration.

    Science.gov (United States)

    Körding, K P; König, P

    2001-01-01

    Many learning rules for neural networks derive from abstract objective functions. The weights in those networks are typically optimized utilizing gradient ascent on the objective function. In those networks each neuron needs to store two variables. One variable, called activity, contains the bottom-up sensory-fugal information involved in the core signal processing. The other variable typically describes the derivative of the objective function with respect to the cell's activity and is exclusively used for learning. This variable allows the objective function's derivative to be calculated with respect to each weight and thus the weight update. Although this approach is widely used, the mapping of such two variables onto physiology is unclear, and these learning algorithms are often considered biologically unrealistic. However, recent research on the properties of cortical pyramidal neurons shows that these cells have at least two sites of synaptic integration, the basal and the apical dendrite, and are thus appropriately described by at least two variables. Here we discuss whether these results could constitute a physiological basis for the described abstract learning rules. As examples we demonstrate an implementation of the backpropagation of error algorithm and a specific self-supervised learning algorithm using these principles. Thus, compared to standard, one-integration-site neurons, it is possible to incorporate interesting properties in neural networks that are inspired by physiology with a modest increase of complexity.

  6. 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

  7. 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

  8. Sandwich Structures from Arbitrary Functions in Group Theory

    OpenAIRE

    Hawthorn, Ian

    2017-01-01

    Functions between groups with the property that all function con- jugates are inverse preserving are called sandwich morphisms. These maps pre- serve a structure within the group known as the sandwich structure. Sandwich structures are left distributive idempotent left involutary magmas. These pro- vide a generalisation of groups which we call a sandwich. This paper explores sandwiches and their relationship to groups.

  9. 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.

  10. 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.)

  11. 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

  12. Interference of immunoglobulins in two glucagon radioimmunoassays

    International Nuclear Information System (INIS)

    Von Schenck, H.; Grubb, A.O.

    1982-01-01

    Radioimmunoassays of glucagon in plasma may be complicated by interaction with other substances of high molecular mass. Precipitates of such substances with ammonium sulfate showed, after isoelectric focusing, two fractions having glucagon immunoreactivity. One fraction (pI approx.10) evidently is associated with the Fc portion (but not the Fab portion) of purified polyclonal immunoglobulin G (IgG). Equal amounts of purified monoclonal IgG of various subclasses, especially IgG 1, gave different ''glucagon'' readings, suggesting that some IgG may interfere more strongly than others. The other fraction (pI 5-6) appeared less consistently, and on gel chromatography appeared to be slightly larger than IgG. Together these fractions add about 50-100 ng/L to the immunoreactive glucagon values in plasma. Therefore methods in which glucagon is extracted before assay should be used for determining the concentration of glucagon present physiologically

  13. Studies on a radioimmunoassay for human erythopoietin.

    Science.gov (United States)

    Lertora, J J; Dargon, P A; Rege, A B; Fisher, J W

    1975-07-01

    A highly purified erythropoietin (ESF) preparation (12,000 units per milligram of protein) was labeled with Na'125I using the Chloramine-T method. Undamaged immunoreative labeled ESF was separated from the damaged, nonimmunologically receiveESF by Sephadex G-150 fractionation. This undamaged immunreactive ESF was usedin radioimmunoassay for human erythropoietin. Separation of bound from free antigen was acheived using the double-antibody technique. Approximately 55 per cent binding wasobserved at an antiserum dilution of 1:1500. This assay appears to be sensitive enough to detect as little as 0.025 milliunits of the International Reference Preparation erythropoietin. The estimated levels of thid hormone in normal and anemic uremic human subjects suggests that immunoreactive serum erythropoietin levels are elevated above normal in anemia of uremia.

  14. 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

  15. A direct radioimmunoassay for aldosterone in plasma

    International Nuclear Information System (INIS)

    Lun, S.; Espiner, E.A.; Nicholls, M.G.; Yandle, T.G.

    1983-01-01

    This rapid radioimmunoassay for aldosterone is performed directly on 100 microL of unprocessed plasma, with 125 I-labeled aldosterone as the labeled antigen. Researchers use of steroid-free plasma in preparing the standard curve resulted in an overestimate of aldosterone; this problem was overcome by adding to such plasma a mixture of other steroids to provide a constant steroid/aldosterone ratio. Over a wide range of aldosterone concentrations, results agreed well between the present assay and a routine method involving solvent extraction and paper chromatography (r . 0.85), and sensitivity (20 ng/L) and inter- (10.4%) and intra- (3.9%) assay CVs were better with the present assay. This assay is especially useful for multiple samples and (or) when only small-volume samples are available

  16. A sensitive radioimmunoassay of scorpion neurotoxin

    International Nuclear Information System (INIS)

    Tessier, M.; Delori, P.; Bechis, G.; Rochat, H.

    1978-01-01

    Scorpion neurotoxins form a family of homologous proteins which are basic and have approx. mol. wt. 7000. They consist of a single peptide chain crosslinked by four disulfide bridges. The complete amino acid sequences of some of them as well as the N-terminal of others, have been determined: their comparison has led to a classification into four groups. They have been shown to affect the conduction of ions through membrane channels and are thus good tools for the study of these structures on the molecular level. Toxins I and II of Androctonus australis Hector have been labelled with 125 I and specific radioactivities up to 2000 Ci/mmol have been obtained. Here the setting up of a radioimmunoassay allowing a sensitive and specific detection of toxin I of Androctonus australis Hector is reported

  17. 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)

  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. 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.)

  1. 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)

  2. 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

  3. 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.)

  4. Studies for the establishment of a radioimmunoassay for the detection of rubella-specific antibodies in human serum

    International Nuclear Information System (INIS)

    Buchow, B.

    1982-01-01

    Studies were undertaken for the development of a solid-phase radioimmunoassay (RIA) for the recognition of rubella-specific antibodies in human serum. For this a rubella antigen, which can be found on the market for routine serological diagnostics and which is used for the hemagglutinin inhibition test (HAH; Behringwerke, Marburg), was used directly as an antigen in the RIA. A 'direct' RIA was run to establish a competition test as well as an 'indirect' RIA using the sandwich technique. A differentiation between antibody-positive and antibody-free patient serum could not be attained either by the direct or indirect RIA. The reason lay with the unsuitability of the rubella antigen used for the RIA. It is discussed, that the composition of the antigen from the supernatant of rubella-infected cell cultures and foreign protein is responsible for the non-specificity of the antibody bondings. (orig./TRV) [de

  5. Composite Sandwich Technologies Lighten Components

    Science.gov (United States)

    2010-01-01

    Leveraging its private resources with several Small Business Innovation Research (SBIR) contracts with both NASA and the U.S. Department of Defense, WebCore Technologies LLC, of Miamisburg, Ohio, developed a fiber-reinforced foam sandwich panel it calls TYCOR that can be used for a wide variety of industrial and consumer applications. Testing at Glenn Research Center?s Ballistic Impact Facility demonstrated that the technology was able to exhibit excellent damage localization and stiffness during impact. The patented and trademarked material has found use in many demanding applications, including marine, ground transportation, mobile shelters, bridges, and most notably, wind turbines.

  6. A solid-phase radioimmunoassay for detection of tetanus antibodies

    International Nuclear Information System (INIS)

    Dow, B.C.; Barr, A.; Crawford, R.J.; Mitchell, R.

    1983-01-01

    A solid-phase radioimmunoassay has been developed as a screening technique for tetanus antibodies in blood plasma. It is based on the principle of a commercial test for Hepatitis B antibody. Compared to previous screening techniques, the radioimmunoassay showed better stability with no apparent loss of sensitivity over a 2 month period. This technique has proved useful in determining tetanus immunity and in monitoring free antibody level in treated cases of clinical tetanus. (U.K.)

  7. 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

  8. Compressive properties of sandwiches with functionally graded ...

    Indian Academy of Sciences (India)

    Developing newer and utilitarian functionally graded systems using ashes is an interesting and challenging task. Though the concept of FG core in a sandwich and its implication on mechanical performance of sandwich struc- tures is available in early literature (Mouritz and Thomson. 1999; Evans et al 2001; Najafizadeh ...

  9. Advanced Mechanical Testing of Sandwich Materials

    DEFF Research Database (Denmark)

    Hayman, Brian; Berggreen, Christian; Jenstrup, Claus

    2008-01-01

    An advanced digital optical system has been used to measure surface strains on sandwich face and core specimens tested in a project concerned with improved criteria for designing sandwich X-joints. The face sheet specimens were of glass reinforced polyester and were tested in tension. The core sp...

  10. Natural fabric sandwich laminate composites: development and ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 1 ... Natural fabrics; jute; linen; sandwich laminate; mechanical properties; fractographic analysis. ... In this work, eco-friendly natural fabric sandwich laminate (NFSL) composites are formulated using jute and linen-fabric-reinforced epoxy with different layer ...

  11. Development of radioimmunoassay for prolactin binding protein

    International Nuclear Information System (INIS)

    Raikar, R.S.; Sheth, A.R.

    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 10 M -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. (author)

  12. 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

  13. The radioimmunoassay of human serum inhibin

    International Nuclear Information System (INIS)

    McLachlan, R.; Robertson, D.M.; Healy, D.L.; Findlay, J.K.; De Kretser, D.M.; Burger, H.G.

    1987-01-01

    The measurement of circulating inhibin is essential to the advancement of our understanding of its role in the control of FSH secretion. Recently, sensitive in vitro bioassay systems have been described which have allowed the measurement of inhibin bioactivity in the peripheral serum of immature female rats, sheep and women (C. Tsonis, personal communication) following ovarian hyperstimulation with exogenous gonadotrophins. Inhibin bioactivity has also been shown to rise in ovarian venous blood in the late follicular phase of women and during FSHG administration to primates. Such studies have some important limitations, in particular, the bioassay systems employed lack the sensitivity required for the study of normal physiology, and questions regarding the specificity of in vitro bioassay in application to serum samples have arisen following the reports of FSH releasing factors (transforming growth factor-beta inhibin B subunit dimers) that may confound the accurate assessment of inhibin bioactivity. This paper reports on the development of sensitive and specific radioimmunoassay (RIA) systems applicable to human serum utilizing highly purified preparations of 58kDa and 31kDa bovine follicular fluid (bFF) inhibin. The development of two RIA systems utilizing antisera raised to either or 31kDa bFF inhibin is detailed and their application to the study of inhibin physiology in the human female during ovulation inducting, the normal menstrual cycle and gestation described

  14. 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

  15. 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

  16. 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

  17. 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

  18. Quantitative human chorionic gonadotropin analysis. I. Comparison of an immunoradiometric assay and a radioimmunoassay

    International Nuclear Information System (INIS)

    Shapiro, A.I.; Wu, T.F.; Ballon, S.C.; Lamb, E.J.

    1984-01-01

    An immunoradiometric assay (IRMA) for the quantitative analysis of human chorionic gonadotropin (hCG) was evaluated for specificity, sensitivity, accuracy and precision. The results were compared with those of the conventional radioimmunoassay (RIA) used in our laboratory. The IRMA is a solid-phase, double-antibody immunoassay that sandwiches the intact hCG molecule between the two antibodies. It has specificity, accuracy, and precision which are similar to those of the RIA. The RIA is based upon the assumptions that the antigenicity of the tracer is not altered by the iodination process and that the antibody reacts equally with all of the antigens, including the radiolabeled antigen. The IRMA does not use radiolabeled antigens and thus is free of the assumptions made in the conventional RIA. The IRMA may be more accurate at the lower limits of the assay because it does not require logarithmic transformations. Since the IRMA does not measure the free beta-subunit of hCG, it cannot be endorsed as the sole technique to quantitate hCG in patients with gestational trophoblastic neoplasia until the significance of the free beta-subunit in these patients is determined

  19. New "sandwich" structures conformed from three dimensional

    Directory of Open Access Journals (Sweden)

    Alba, Juan J.

    1996-03-01

    Full Text Available Poor interlaminar properties as well as poor-skin-to-core adhesion properties are very often the common existing problems we find when designing with "sandwich" structures. A new type of 3D-fabric "sandwich" structure is being developed in order to avoid these problems. Although the manufacturing process is very simple, a very complex "sandwich" structure is obtained as a result of the complexity of the 3D-fabric used. This 3D-fabric is a 3D woven glass fabric produced on velvet weaving machines with glass yarns. It is an integrally woven "sandwich" laminate for all kinds of composite products. The strength of the vertical fibers makes, that also after impregnation with a resin matrix, the "sandwich" structure is maintained. The result is a laminate with high strength and stiffness and low weight. On each side of this "sandwich" laminate additional reinforcement materials can be laminated and a synthetic foam can be injected in the hollow structure. This will allow to establish the mechanical properties of a finished product.

    Las pobres propiedades, tanto interlaminares como de adhesión entre piel y núcleo, constituyen uno de los grandes problemas cuando se diseñan estructuras utilizando paneles tipo "sandwich". Un nuevo tipo de panel "sandwich", configurado a partir de tejidos tridimensionales, está siendo desarrollado en la actualidad con el objetivo de eliminar esos problemas. Aunque el proceso de fabricación es muy simple, el panel "sandwich" obtenido es de estructura compleja, como resultado de la complejidad del tejido tridimensional utilizado. Este tejido tridimensional (3D es un tejido de fibra de vidrio producido en máquinas de tejer especializadas. La resistencia de las fibras verticales hace que, después de la impregnación con una resina, se mantenga la configuración tipo "sandwich". El resultado es un laminado de alta resistencia, gran rigidez y bajo peso. Sobre cada uno de los lados del panel "sandwich" se pueden

  20. The determination of serum prolactin by radioimmunoassay

    International Nuclear Information System (INIS)

    Tantirasdr, K.

    1980-01-01

    The iodination of hPRL with 125 I utilizing chloramine-T technique at temperature 4 degrees C gave 125 I-hPRL having immunoreactivity. 125 I-hPRL could be used as a labelled compound for determination of human prolactin by radioimmunoassay. The assay was performed using 125 I-hPRL 5,000 cpm/tube and anti-hPRL 1 : 400,000 dilution (final) incubated at 25 degrees C for 24 hr. One percent dextran-coated charcoal suspension (0.5 ml) was used for separation of free from bound form. The criteria of reliability of the method was evaluated in terms of accuracy, precision, specificity and sensitivity. Under the condition of the assay, the addition of known amount of hPRL (6-50 ng/ml) to charcoaled serum, the recovery of the added hPRL was found to be 97.3-120.8%. The within and between assay variation were evaluated from replicate measurements of the same samples in the same assay and in three different assays. The percentage coefficients of variation was found to be 7.7-15.8% and 13.1-24.0% for within and between assays respectively. Cross-reactivities of tested several protein hormones indicated that the anti-hPRL was very specific. The sensitivity was found to be 1.90 ng/ml. The method was applied to measure serum prolactin for one cycle of 4 volunteers Thai women having normal menstrual cycle. The mean ± S D of serum prolactin was found to be 15.9 ± 5.6, 21.2 ± 12.7 and 16.4 ± 6.2 ng/ml at follicular phase, mid-cycle and luteal phase respectively

  1. 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

  2. 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

  3. Compressive properties of sandwiches with functionally graded ...

    Indian Academy of Sciences (India)

    rediffmail.com) construction industry and is now used in civil engineering applications (Keller 2006). Recent applications have demon- strated that fiber composite sandwich construction can be effectively and economically used in the civil ...

  4. 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.)

  5. 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

  6. Logistics of national radioimmunoassay services and radioimmunoassay trouble shooting in developing countries

    International Nuclear Information System (INIS)

    Hazra, D.K.; Shukla, A.K.; Arvind, B.; Khandelwal, S.; Singh, R.; Lahiri, V.L.

    1986-01-01

    The logistics of national radioimmunoassay services are analysed in regard to: applications of immunoassays in developing countries; provision of matched reagents; collection, storage and transport of patient samples, particularly from rural areas; development of robust new immunoassay systems, especially those using non-isotopic labels; quality control; and interrelation with international agencies and commercial suppliers. The effect of using different methods and temperatures of sample storage on representative glycoprotein, steroid, thyroid and communicable disease analytes is examined. The need for stratification of assay services (district, state and national/regional levels) for various tests is discussed in relation to their clinical urgency. A trouble shooting guide suited to developing countries has been written. Starting from various symptoms of assay failure, it describes the differential diagnosis of likely causes, lists appropriate tests to confirm the diagnosis and finally suggests remedial action to prevent future similar mishaps or to salvage the assay. (author)

  7. Direct radioimmunoassay and immunocytochemical localization of renin in human kidneys

    International Nuclear Information System (INIS)

    Menard, J.; N'Goc, P.W.; Bariety, J.; Guyenne, P.T.; Corvol, P.

    1979-01-01

    Highly specific antibodies to human renin were prepared in rabbits and used for the preparation of a renin-free substrate, the direct radioimmunoassay of renin in plasma and kidneys, and the localization of renin with fluoresceinated antibodies. In a patient with a partially infarcted kidney, plasma renin activity, measured enzymatically by the radioimmunoassay of angiotensin I, was increased, and could be activated by acid. The direct measurement of plasma renin by radioimmunoassay gave identical values before and after acidification. In the ischaemic part of the kidney, renin content was high, both by the enzymatic and the direct method of measurement. It was low in the non-ischaemic part of the kidney. Thus whereas renin has been previously measured as an activity by enzymatic assays, this intra-renal hormone can now be measured as an entity by a specific radioimmunoassay in human plasma and kidney tissue. All afferent and some interlobular arteries of the obsolescent glomeruli were stained with fluoresceinated anti-renin antibodies. In the non-ischaemic area, the juxtaglomerular apparatus did not stain. (author)

  8. Cost/benefit and predictive value of radioimmunoassay

    International Nuclear Information System (INIS)

    Albertini, A.; Ekins, R.P.; Galen, R.S.

    1984-01-01

    The present symposium is organized to discuss the benefits of radioimmunoassay. The discussion includes several aspects: the real diagnostic values of the measurements; the way of organization to maximise the diagnostic reliability and usefulness whilst minimizing the real costs; the prospects existing for the improvement of current methods and, implicitly, of cost/benefit ratios. (Auth.)

  9. A solid-phase-radioimmunoassay for total serum thyroxine

    International Nuclear Information System (INIS)

    Moedder, G.; Sokolowski, G.

    1978-01-01

    A new solid phase radioimmunoassay for total serum thyroxine was evaluated over a longer time under clinical routine conditions and compared with an established test system. The results show up that the T 4 values are precise, reliable and reproducible, the is incomplicate to handle and well suitable for semiautomatic pipetting systems. (orig.) 891 MG [de

  10. 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)

  11. 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

  12. Bile canalicular dynamics in hepatocyte sandwich cultures.

    Science.gov (United States)

    Reif, Raymond; Karlsson, Johan; Günther, Georgia; Beattie, Lynette; Wrangborg, David; Hammad, Seddik; Begher-Tibbe, Brigitte; Vartak, Amruta; Melega, Simone; Kaye, Paul M; Hengstler, Jan G; Jirstrand, Mats

    2015-10-01

    Many substances are hepatotoxic due to their ability to cause intrahepatic cholestasis. Therefore, there is a high demand for in vitro systems for the identification of cholestatic properties of new compounds. Primary hepatocytes cultivated in collagen sandwich cultures are known to establish bile canaliculi which enclose secreted biliary components. Cholestatic compounds are mainly known to inhibit bile excretion dynamics, but may also alter canalicular volume, or hepatocellular morphology. So far, techniques to assess time-resolved morphological changes of bile canaliculi in sandwich cultures are not available. In this study, we developed an automated system that quantifies dynamics of bile canaliculi recorded in conventional time-lapse image sequences. We validated the hepatocyte sandwich culture system as an appropriate model to study bile canaliculi in vitro by showing structural similarity measured as bile canaliculi length per hepatocyte to that observed in vivo. Moreover, bile canalicular excretion kinetics of CMFDA (5-chloromethylfluorescein diacetate) in sandwich cultures resembled closely the kinetics observed in vivo. The developed quantification technique enabled the quantification of dynamic changes in individual bile canaliculi. With this technique, we were able to clearly distinguish between sandwich cultures supplemented with dexamethasone and insulin from control cultures. In conclusion, the automated quantification system offers the possibility to systematically study the causal relationship between disturbed bile canalicular dynamics and cholestasis.

  13. Behaviour of Metal Foam Sandwich Panels

    DEFF Research Database (Denmark)

    Alkhudery, Hayder; Virdi, Kuldeep

    2011-01-01

    Sandwich panels as used in structures comprise of a foam core enclosed by thin high strength steel faces. This paper discusses currently design formulae of local buckling behaviour of such panels using the finite element method. Multiple wave finite element models were adopted to investigate...... and examine the adequacy of currently used approach for the design of sandwich panels. The paper presents brief details of the finite element model used including geometry, load pattern and boundary conditions. The selected model gives good agreement with experimental results from Pokharel and Mahendran (2003......). The study shows that currently available design formulae are conservative for stocky sandwich plate elements while being over-conservative for high slenderness. A unified design formula of local buckling behaviour applicable to the full range of slenderness is developed....

  14. Vibro-acoustics of lightweight sandwich structures

    CERN Document Server

    Lu, Tianjian

    2014-01-01

    Vibro-Acoustics of Lightweight Sandwich Structures introduces the study of the coupled vibration and acoustic behavior of lightweight sandwich structures in response to harmonic force and sound pressure. This book focuses on the theoretical modeling and experimental investigation of lightweight sandwich structures in order to provide a predictive framework for vibro-acoustic characteristics of typical engineering structures. Furthermore, by developing solution tools, it concentrates on the influence of key systematic parameters leading to effective guidance for optimal structure design toward lightweight, high-stiffness and superior sound insulation capability. This book is intended for researchers, scientists, engineers and graduate students in mechanical engineering especially in structural mechanics, mechanics and acoustics. Fengxian Xin and Tianjian Lu both work at the School of Aerospace, Xi’an Jiaotong University.

  15. Behavior of sandwich panels in a fire

    Science.gov (United States)

    Chelekova, Eugenia

    2018-03-01

    For the last decades there emerged a vast number of buildings and structures erected with the use of sandwich panels. The field of application for this construction material is manifold, especially in the construction of fire and explosion hazardous buildings. In advanced evacu-ation time calculation methods the coefficient of heat losses is defined with dire regard to fire load features, but without account to thermal and physical characteristics of building envelopes, or, to be exact, it is defined for brick and concrete walls with gross heat capacity. That is why the application of the heat loss coefficient expression obtained for buildings of sandwich panels is impossible because of different heat capacity of these panels from the heat capacities of brick and concrete building envelopes. The article conducts an analysis and calculation of the heal loss coefficient for buildings and structures of three layer sandwich panels as building envelopes.

  16. Behavior of sandwich panels in a fire

    Directory of Open Access Journals (Sweden)

    Chelekova Eugenia

    2018-01-01

    Full Text Available For the last decades there emerged a vast number of buildings and structures erected with the use of sandwich panels. The field of application for this construction material is manifold, especially in the construction of fire and explosion hazardous buildings. In advanced evacu-ation time calculation methods the coefficient of heat losses is defined with dire regard to fire load features, but without account to thermal and physical characteristics of building envelopes, or, to be exact, it is defined for brick and concrete walls with gross heat capacity. That is why the application of the heat loss coefficient expression obtained for buildings of sandwich panels is impossible because of different heat capacity of these panels from the heat capacities of brick and concrete building envelopes. The article conducts an analysis and calculation of the heal loss coefficient for buildings and structures of three layer sandwich panels as building envelopes.

  17. Microbiomes of American Oysters (Crassostrea virginica) Harvested from Two Sites in the Chesapeake Bay.

    Science.gov (United States)

    Ossai, Sylvia; Ramachandran, Padmini; Ottesen, Andrea; Reed, Elizabeth; DePaola, Angelo; Parveen, Salina

    2017-07-27

    In this study, we used 16S rRNA gene amplicons to describe the bacterial microbiota associated with oysters ( Crassostrea virginica ) and seawater collected from two sites in the Chesapeake Bay. The dominant bacterial groups included those belonging to the order Pelagibacteraceae , family Enterobacteriaceae , and genus Synechococcus The microbiomes varied among oysters from the same site and between the two sites and months. Copyright © 2017 Ossai et al.

  18. Buckling driven debonding in sandwich columns

    DEFF Research Database (Denmark)

    Østergaard, Rasmus Christian

    2008-01-01

    results from two mechanisms: (a) interaction of local debond buckling and global buckling and (b) the development of a damaged zone at the debond crack tip. Based on the pronounced imperfection sensitivity, the author predicts that an experimental measurement of the strength of sandwich structures may......A compression loaded sandwich column that contains a debond is analyzed using a geometrically non-linear finite element model. The model includes a cohesive zone along one face sheet/core interface whereby the debond can extend by interface crack growth. Two geometrical imperfections are introduced...

  19. Buckling Analysis of Edge Cracked Sandwich Plate

    Directory of Open Access Journals (Sweden)

    Rasha Mohammed Hussein

    2016-07-01

    Full Text Available This work presents mainly the buckling load of sandwich plates with or without crack for different cases. The buckling loads are analyzed experimentally and numerically by using ANSYS 15. The experimental investigation was to fabricate the cracked sandwich plate from stainless steel and PVC to find mechanical properties of stainless steel and PVC such as young modulus. The buckling load for different aspect ratio, crack length, cracked location and plate without crack found. The experimental results were compared with that found from ANSYS program. Present of crack is decreased the buckling load and that depends on crack size, crack location and aspect ratio.

  20. OPTIMAL DESIGN OF QUADRATIC SANDWICH PLATE

    Directory of Open Access Journals (Sweden)

    TIMAR Dr. Imre

    2016-05-01

    Full Text Available In this paper, we show the optimal design of the three-layered sandwich plates. The objective function contains the material and fabrication costs. The design constraints are the maximal stresses, the deflection of plates and damping of vibrations. The unknown is the thickness of the filling foam. By the mathematical method, we define the minima of the cost function and the optimal thickness of the filling layer of foam. The active constraint is the deflection, so we calculate of the costs of the sandwich plate with the homogeneous plate.

  1. AA, sandwich line with magnetic horn

    CERN Document Server

    CERN PhotoLab

    1980-01-01

    The magnetic horn, focusing the antiprotons emanating from the target, was affixed to a sandwich line through which the 150 kA pulses were supplied. Expecting to have to change from time to time the fragile horn (inner conductor only 0.7 mm thick), the assembly was designed for quick exchange. At the lower end of the sandwich line we see the connectors for the high-current cables, at the upper end the magnet horn. It has just been lifted from the V-supports which held it aligned downstream of the target. Continue with 8010293.

  2. Establishment of an indirect solid phase radioimmunoassay for the detection of HSV-type I-specific antibodies in human serum

    International Nuclear Information System (INIS)

    Buchow, H.

    1982-01-01

    An indirect solid phase radioimmunoassay (IFRIA) was developed for the detection in human serum of antibodies against Herpes simplex virus (HSV) type I. The IFRIA was carried out according to the 'sandwich' principle. In comparison to other serological routine methods, especially the complement binding reaction (CBR) commonly used for HSV diagnostic, the IFRIA excelled by being a test which is quick to carry out and by lacking the subjectivity by the researcher in the evaluation of the test results, as well as by the use of patients serum which had not been previously treated. Comparative studies between IFRIA and CBR resulted in no agreement between the respectively attained maximum titer. As a reason for this the different qualities of the antibodies which can be determined by each test were discussed. For the addition of this test to the routine diagnostic further studies in the preservation of the specificity of the antigen in the case of longer storage are requisite. (orig.) [de

  3. β2-microglobulin, albumin radioimmunoassay and its clinical appraisal

    International Nuclear Information System (INIS)

    Yu Yuming; Zhu Qiyuan; Cheng Guangliang

    1994-01-01

    The β 2 -MG, Alb RIA kits were made in the Radioisotope Department of China Institute of Atomic Energy. They may be used as new type kits inspecting the function indexes of kidney. In the report, these kits are considered to be of high quality by the data of 15 tests. The serum and urine β 2 -MG and urine Alb values of 82 normal subjects and 210 abnormal subjects of different kidney diseases are measured by radioimmunoassay. The results show that the values of β 2 -MG and Alb values of the patients are significantly higher than that of healthy subjects. It is suggested that the β 2 -MG and Alb values measured by radioimmunoassay are very useful and sensitive function indexes of kidney in the clinical diagnosis of different kidney diseases

  4. Development of antiserum against bovine prolactin for radioimmunoassay

    International Nuclear Information System (INIS)

    Razdan, M.N.; Kaker, M.L.; Galhotra, M.M.

    1980-01-01

    Antiserum against bovine prolactin was raised in male rabbits and tested against crossreacting contaminants by immunodiffusion and immunoelectrophoresis. One sharp precipitin band against prolactin was observed. The antiserum showed a small faint band against bovine growth hormone. No crossreaction was observed against bovine follicle stimulating hormone, bovine luteinizing hormone, bovine thyroid stimulating hormone and normal calf serum. The crossreaction with bovine growth hormone vanished after treating the antiserum with normal calf serum. Antibody titre of the absorbed anti-prolactin serum determined by radioimmunoassay was high, which could bind 31.30% at 1:10,000 final dilution. Maximum binding was not inhibited by the addition of higher amounts of contaminants, suggesting that the absorbed antiserum was immunologically monospecific and could be used for radioimmunoassay work. (author)

  5. Radioimmunoassay of steroids in Czechoslovakia - current state and prospects

    International Nuclear Information System (INIS)

    Hampl, R.; Starka, L.; Putz, Z.; Dvorak, P.

    1984-01-01

    The experience is summarized with radioimmunoassay of steroids during the last 15 years, and the expected trends in this field are dealt with. The following problems connected with the radioimmunoassay of steroids are discussed: 1) ways leading to improved antisera specificity (choice of immunogen, use of the principle of immunological tolerance, use of antisera mixtures, preparation of monoclonal antibodies); 2) methods of ligand labelling (steroids labelled in the ring, radioiodine labelled derivative); 3) separation techniques of bound and free ligands; 4) sample preparation with regard to automation and 5) importance of and approaches to the determination of free, plasma protein non-bound steroids. The survey is complemented with a list of antisera to steroids, prepared in the laboratories of the authors. (author)

  6. Radioimmunoassay for nortriptyline (and other tricyclic antidepressants) in plasma

    International Nuclear Information System (INIS)

    Maguire, K.P.; Burrows, G.D.; Norman, T.R.; Scoggins, B.A.

    1978-01-01

    The radioimmunoassay for nortriptyline described here can detect as little 1 μg/liter of plasma. Within-day precision and day-to-day precision (CV) were +-6 and +-11%, respectively, over the concentration range 100 to 200 μg/liter. The major metabolite hydroxy-nortriptyline does not cross react with the antiserum. Results so obtained correlate closely with results by a double-isotope derivative dilution technique. The major advantages of this technique over currently available methods are its sensitivity, convenience (many samples can be processed in one day), simplicity, and cost. Further, prior extraction of plasma samples is not required. Cross-reactivity studies have been carried out with all other available tricyclic antidepressants. The antiserum has the ability to bind these drugs, thus radioimmunoassay for all the tricyclic antidepressant drugs can be set up because concurrent use of more than one of these drugs is rare

  7. Quantitation of avian RNA tumor virus reverse transcriptase by radioimmunoassay

    International Nuclear Information System (INIS)

    Panet, A.; Baltimore, D.; Hanafusa, T.

    1975-01-01

    A radioimmunoassay was developed that can detect and quantitate 3 ng or more of the avian RNA tumor virus reverse transcriptase. The assay detected no antigenic sites in Rous sarcoma virus α virions or in virions of a murine RNA tumor virus. About 70 molecules of reverse transcriptase were found per virion of avian myeloblastosis virus with this assay or with an assay based on antibody inhibition of enzymatic activity. The assay detected about 270 ng of enzyme per mg of cell protein in virus-producing cells; uninfected cells had much less antigenic material but contained some determinants able to displace radioactive antigen. No additional antigenic determinants on reverse transcriptase could be detected that were not found on the separated α subunit of the enzyme. Although sevenfold less sensitive than enzymatic activity as a measure of reverse transcriptase, the radioimmunoassay can detect antigen using small amounts of protein and in the presence of inhibitors

  8. Career Counseling for the Sandwich Generation.

    Science.gov (United States)

    Byrd, Virginia

    The Sandwich Generation refers to individuals who have multiple caregiving responsibilities for children under 18, as well as parents, grandparents or other aging relatives. Employees who are the caregivers cannot help but bring the stress of the situation to the workplace. Existing research suggests that these responsibilities take a toll on…

  9. Comprehensive overview of theories for sandwich panels

    NARCIS (Netherlands)

    Straalen, IJ.J. van

    1998-01-01

    This paper gives a comprehensive overuiew of theories for sandwich panels, dealing with the mechanical behaviour. The c/assica/ theories are mainly formulated during the fifties and sixties. The derived analytical solutions are based on simplified assumptions. To study local effects near suppotls,

  10. Understanding Successful Sandwich Placements: A Bourdieusian Approach

    Science.gov (United States)

    Clark, Martyn; Zukas, Miriam

    2016-01-01

    Sandwich placements and other integrated work and study schemes are increasingly advocated as a key means by which universities can promote students' employability. However, there is little understanding of how successful placements work in terms of facilitating learning and development. Drawing on three longitudinal case studies of students who…

  11. AA, sandwich line with magnetic horn

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    Continuation from 8010293: Finally, the sandwich line with the horn is placed on the ground, for the horn to be inspected and, if needed, exchanged for a new one. The whole procedure was trained with several members of the AA team, for quick and safe handling, and to share the radiation dose amongst them.

  12. Regenerated thermosetting styrene-co-acrylonitrile sandwich ...

    Indian Academy of Sciences (India)

    ... kJ m−2, 41.7 MPa, and 61.0 MPa, respectively. Good interfacial bonding between DMAc-treated fibres and SAN matrix was verified by peel test and exhibited in SEM photographs. Besides, the water absorption of DMAc-treated fibres composite was lower than other SAN/jute fibre-reinforced sandwich composite panels.

  13. Compressive properties of sandwiches with functionally graded ...

    Indian Academy of Sciences (India)

    The compressive behaviour of a new class of sandwich composite made up of jute fiber reinforced epoxy skins and piece-wise linear fly ash reinforced functionally graded (FG) rubber core is investigated in flat-wise mode. FG samples are prepared using conventional casting technique. Presence of gradation is quantified ...

  14. Regenerated thermosetting styrene-co-acrylonitrile sandwich ...

    Indian Academy of Sciences (India)

    exhibited in SEM photographs. Besides, the water absorption of DMAc-treated fibres composite was lower than other SAN/jute fibre-reinforced sandwich composite panels. Keywords. Jute fibre composite; thermosetting SAN; regeneration; fibre surface treatment; mechanical property; water absorption. 1. Introduction.

  15. Natural fabric sandwich laminate composites: development and ...

    Indian Academy of Sciences (India)

    Natural fabrics; jute; linen; sandwich laminate; mechanical properties; fractographic analysis. 1. Introduction. Owing to ecological necessities and strict regulations, incor- porating natural fibres in the place of synthetic fibres becomes inevitable for the manufacturers to accomplish new composite materials originated from ...

  16. X-joints in composite sandwich panels

    NARCIS (Netherlands)

    Vredeveldt, A.W.; Janssen, G.Th.M.

    1998-01-01

    The small structural weight of fast large ships such as fast mono hulls or catamaran type of ships is of extreme importance to their success. One possible light weight structural solution is the sandwich panel with fibre reinforced laminates and a balsa, honeycomb or foam core. A severe obstacle for

  17. Natural fabric sandwich laminate composites: development and ...

    Indian Academy of Sciences (India)

    Sci., Vol. 40, No. 1, February 2017, pp. 139–146. c Indian Academy of Sciences. DOI 10.1007/s12034-016-1356-y. Natural fabric sandwich laminate composites: development and investigation ... studied by Gassan and Bledzki [17]. An investigation on the ... spread with the aid of a brush. Another layer of reinforce- ment in ...

  18. Compressive properties of sandwiches with functionally graded

    Indian Academy of Sciences (India)

    The compressive behaviour of a new class of sandwich composite made up of jute fiber reinforced epoxy skins and piece-wise linear fly ash reinforced functionally graded (FG) rubber core is investigated in flat-wise mode. FG samples are prepared using conventional casting technique. Presence of gradation is quantified ...

  19. A specific radio-immunoassay for Gonadotrophin-releasing hormone

    International Nuclear Information System (INIS)

    Hendricks, S.; Millar, R.; Pimstone, B.

    1975-01-01

    A specific antiserum has been made to synthetic gonadotrophin-releasing hormone (GnRH) conjugated to keyhole limpet haemocyanin and appears to be directed against amino acids 6 - 8 of this decapeptide. This has allowed the development of a radio-immunoassay for GnRH sensitive to 5 picograms per tube. Although it is easily measurable in hypothalamic extracts, we have failed to detect GnRH in plasma and urine from normal subjects and menopausal women

  20. A micro-radioimmunoassay for measurement of rat luteinizing ...

    African Journals Online (AJOL)

    A sensitive and reproducible double antibody radio-immunoassay for rat LH measurement, which requires at most 50μl of serum or plasma per tube, is described for use with 125l and rabbit anti-rat LH serum. The assay has a scnsitivity of 16 ng LH/ml, and coefficients of inter-assay and intra-assay variations of +/-6,6% and ...

  1. Semiautomated radioimmunoassay for mass screening of drugs of abuse

    International Nuclear Information System (INIS)

    Sulkowski, T.S.; Lathrop, G.D.; Merritt, J.H.; Landez, J.H.; Noe, E.R.

    1975-01-01

    A rapid, semiautomated radioimmunoassay system for detection of morphine, barbiturates, and amphetamines is described. The assays are applicable to large drug abuse screening programs. The heart of the system is the automatic pipetting station which can accomplish 600 pipetting operations per hour. The method uses 15 to 30 μl for the amphetamine and combined morphine/barbiturate assays. A number of other drugs were tested for interference with the assays and the results are discussed

  2. Synthesis of iodobuprenorphine for use in radioimmunoassay. [Analgesic

    Energy Technology Data Exchange (ETDEWEB)

    Debrabandere, L.; Boven, M. van; Daenens, P. (Leuven Univ. (Belgium). Lab. of Toxicology)

    1992-08-01

    The synthesis of [[sup 125]I]iodobuprenorphine is described. This compound has been used as a tracer molecule in the development of a new radioimmunoassay for buprenorphine. The parameters that effect the direct iodination of buprenorphine using sodium [[sup 127]I]iodide, in the presence of either chloramine-T or Iodo-Beads, were studied. The structure of iodobuprenorphine was confirmed by mass spectrometry. (author).

  3. Preparation and characterization of reagents for epitestosterone radioimmunoassay

    International Nuclear Information System (INIS)

    Bilek, R.; Hampl, R.; Starka, L.; Putz, Z.

    1987-01-01

    The preparation of reagents, suitable for radioimmunoassay of 17α-hydroxy-4-androsten-3-one (epitestosterone) in body fluids is described. It includes a simplified synthesis of the immunogen, epitestosterone-3-(0-carboxymethyl)oxime coupled to bovine serumalbumin its characterization and preparation of the radioligand ( 125 I) iodohistaminyl derivative of epitestosterone. The assay protocol for epitestosterone detection in urine avoiding extraction is described and the reliability criteria of the method are given. (author)

  4. Automation of steroid radioimmunoassays for clinical and research purposes

    International Nuclear Information System (INIS)

    Vihko, R.; Hammond, G.L.

    1979-01-01

    In recent years an exponential increase in the research and clinical application of radioimmunoassays has created a demand for manipulative aids, to increase the general efficiency of the technique as well as precision of the determinations. At present a number of systems exist for sample preparation and the automation of assays. However, due to inherent problems of carry-over, priming, cleaning and the necessity for chemically inert components most of these systems tend to be rather inflexible. The instrument of choice ought therefore to be extremely versatile and provide the operator with a wide spectrum of alternatives, in order to optimize the initial capital outlay. Moreover, in the light of technological developments in the field of simultaneous, multisample gamma-counting and data processing, it is anticipated that a new generation of multisample processors will emerge of sufficient flexibility to accommodate the wide variety of assay protocols in present use. In this paper the problems encountered in the development of automated techniques for the radioimmunoassay of steroid hormones are reviewed, and a preliminary description of a versatile modular discrete instrument for the automation of radioimmunoassays is presented, which is based on simultaneous multisample preparation, and subsequent counting and data processing. (author)

  5. 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

  6. Structural Analysis of Sandwich Foam Panels

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, Jan [ORNL; Huo, X. Sharon [Tennessee Technological University

    2010-04-01

    The Sandwich Panel Technologies including Structural Insulated Panels (SIPs) can be used to replace the conventional wooden-frame construction method. The main purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC and SGI Venture, Inc. was to design a novel high R-value type of metal sandwich panelized technology. This CRADA project report presents design concept discussion and numerical analysis results from thermal performance study of this new building envelope system. The main objective of this work was to develop a basic concept of a new generation of wall panel technologies which will have R-value over R-20 will use thermal mass to improve energy performance in cooling dominated climates and will be 100% termite resistant. The main advantages of using sandwich panels are as follows: (1) better energy saving structural panels with high and uniform overall wall R-value across the elevation that could not be achieved in traditional walls; and (2) reducing the use of raw materials or need for virgin lumber. For better utilization of these Sandwich panels, engineers need to have a thorough understanding of the actual performance of the panels and system. Detailed analysis and study on the capacities and deformation of individual panels and its assembly have to be performed to achieve that goal. The major project activity was to conduct structural analysis of the stresses, strains, load capacities, and deformations of individual sandwich components under various load cases. The analysis simulated the actual loading conditions of the regular residential building and used actual material properties of the steel facings and foam.

  7. One-site versus two-site phacotrabeculectomy: a prospective randomized study

    Directory of Open Access Journals (Sweden)

    Moschos MM

    2015-08-01

    Full Text Available Marilita M Moschos,1 Irini P Chatziralli,2 Michael Tsatsos3 1First Department of Ophthalmology, University of Athens, 2Second Department of Ophthalmology, Ophthalmiatrion Athinon, Athens, Greece; 3Department of Ophthalmology, Cambridge University Hospital NHS, Cambridge, UK Purpose: The purpose of this study is to compare the efficacy and safety of one-site and two-site combined phacotrabeculectomy with foldable posterior chamber intraocular lens implantation.Methods: Thirty-four patients (41 eyes with glaucoma and cataract were randomly assigned to undergo either a one-site (22 eyes or a two-site (19 eyes combined procedure. One-site approach consisted of a standard superior phacotrabeculectomy with a limbus-based conjunctival flap, while two-site approach consisted of a clear cornea phacoemulsification and a separate superior trabeculectomy with a limbus-based conjunctival flap.Results: Mean follow-up period was 54 months (standard deviation [SD] 2.3. Mean preoperative intraocular pressure (IOP in the one-site group was 21.3 mmHg (SD 2.8 and in the two-site group was 21.8 mmHg (SD 3.0 (P>0.1. Mean postoperative IOP significantly decreased in both groups compared to the preoperative level and was 15.6 mmHg (SD 3.5 in the one-site group and 14.9 mmHg (SD 2.7 in the two-site group. Three months later, the difference between the two groups was not statistically significant (P=0.058. The one-site group required significantly more medications than the two-site group (P=0.03. Best-corrected visual acuity (BCVA improved similarly in both groups, but there was less postoperative (induced astigmatism in the two-site group in a marginal statistical level (P=0.058. Intra- and postoperative complications were comparable in the two groups.Conclusion: Both techniques yielded similar results concerning final BCVA and IOP reduction. However, the two-site group had less induced astigmatism and a better postoperative IOP control with less required

  8. A general approach to standardization of the solid-phase radioimmunoassay for quantitation of class-specific antibodies

    International Nuclear Information System (INIS)

    Zollinger, W.D.; Boslego, J.W.

    1981-01-01

    The feasibility of using an anti-human immunoglobulin/human immunoglobulin/[ 125 I]anti-human immunoglobulin 'sandwich' in a solid-phase radioimmunoassay to produce a standard curve which could be used to quantitate antigen-specific antibody of a particular immunoglobulin class was investigated. The amount of secondary antibody (SAb) bound was determined as a function of whether the primary antibody (PAb) was bound to its specific solid-phase antigen or by a solid-phase anti-human immunoglobulin. No significant difference between the two values was observed. Quantitation of anti-tetanus toxoid antibody by this method was in a good agreement with quantitative precipitin tests. Comparison of SAb binding as a function of the way the PAb is bound was extended to class-specific PAb by use of murine monoclonal antibodies to meningococcal antigens. In most cases somewhat greater binding of SAb occurred when PAb was bound to antigen, but in several cases where low avidity antibody and/or poor quality antigens were used, greater SAb binding occurred when PAb was bound by anti-mouse immunoglobulin. The results indicate that this approach may be useful as a general method for standardizing the SPRIA and other solid-phase immunoassays such as the ELISA to measure class-specific antibody. (Auth.)

  9. Buckling optimisation of sandwich cylindrical panels

    Science.gov (United States)

    Abouhamzeh, M.; Sadighi, M.

    2016-06-01

    In this paper, the buckling load optimisation is performed on sandwich cylindrical panels. A finite element program is developed in MATLAB to solve the governing differential equations of the global buckling of the structure. In order to find the optimal solution, the genetic algorithm Toolbox in MATLAB is implemented. Verifications are made for both the buckling finite element code and also the results from the genetic algorithm by comparisons to the results available in literature. Sandwich cylindrical panels are optimised for the buckling strength with isotropic or orthotropic cores with different boundary conditions. Results are presented in terms of stacking sequence of fibers in the face sheets and core to face sheet thickness ratio.

  10. Utilization of Bamboo as Lightweight Sandwich Panels

    Directory of Open Access Journals (Sweden)

    Suthon SRIVARO

    2016-05-01

    Full Text Available Lightweight sandwich panels consisting of bamboo faces and oil palm trunk core were manufactured using melamine urea formaldehyde with the resin content of 250 g/m2 (solid basis. The parameters examined were node and density of bamboo faces. Physical (board density, thickness swelling and water absorption and mechanical (modulus of elasticity and modulus of rupture properties of the sandwich board obtained were investigated and compared with other bamboo products and commercial wood based products. Result showed that this panel had better dimensional stability than those of other bamboo products but lower bending strength. Node of bamboo had no significant effect on any board properties examined. Most of board properties were influenced by bamboo face density. Comparing the properties to commercial wood based products, this panel could be used as wall/floor applications.

  11. Specific and sensitive radioimmunoassay for 3-methoxy-4-hydroxyphenylethyleneglycol (MOPEG)

    Energy Technology Data Exchange (ETDEWEB)

    Keeton, T.K. (Univ. of Texas Health Science Center, San Antonio); Krutzsch, H.; Lovenberg, W.

    1981-02-06

    Antibodies that specifically bind the norepinephrine metabolite 3-methoxy-4-hydroxyphenylethyleneglycol (MOPEG) were produced in rabbits after injection of a derivative of MOPEG conjugated with bovine thyroglobulin. A sensitive radioimmunoassay was devised with this antiserum, in which as little as 0.5 nanogram of MOPEG can be accurately measured with a final antibody dilution of 1:180. The antibody appears to be specific for MOPEG, since tritiated MOPEG was not displaced from the antibodies by norepinephrine, epinephrine, dopamine, serotonin, or their major metabolites, including MOPEG-sulfate (333 nanograms each).

  12. Isotopic methods or immuno diagnosis: The Radioimmunoassay and immunoradiometric assay

    International Nuclear Information System (INIS)

    Caso, R.

    1997-01-01

    This work offers an explanation about the more used isotopic techniques for immuno diagnosis: the radioimmunoassay (RIA) and immunoradiometric assay (IRMA). It describes the basic principles of these assays, the antigen-antibody reaction, the radioiodination methods with I-125 for antigens and antibodies, the purification and characterization of labelled compounds. On the order hand they present work gives a review of the methods for separate the bound and free fractions. At the end it offers the principles of the quality control of immunoassay and the future lines of research in the field of RIA and IRMA

  13. An introduction to radioimmunoassay and related techniques. 3. rev. ed.

    International Nuclear Information System (INIS)

    Chard, T.

    1987-01-01

    This book is designed as an introductory text for the staff of clinical or research laboratories who conduct or intend to conduct radioimmunoassay and related immunoassay techniques, and will also be of great value to the clinicians who make use of such services. The emphasis is on general principles with practical illustrations rather than a detailed and encyclopaedic review of the literature. This 3rd revised edition places more emphasis on alternative labels (non-isotopic immunoassays), the use of labelled antibodies (immunometric assays), and the use of monoclonal antibodies. Both principles and practice are illustrated by diagrams and illustrations. (Auth.)

  14. Prediction of ovulation in women using a rapid progesterone radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, R.; Coults, J.R.T. (Glasgow Univ. (UK))

    1982-02-01

    A rapid (3-h) radioimmunoassay of plasma progesterone has been developed and used successfully to predict the time of ovulation in women undergoing artificial insemination. The results obtained using progesterone levels to date the stage of the cycle were analysed retrospectively by (1) estimation of the length of the ensuing luteal phases and comparison of these with luteal phase lengths of a control group (2) comparison of the dating using progesterone levels with retrospective determination of LH values and (3) by analysis of the dating in cycles in which conception occurred.

  15. Purification of subunits from human chorionic gonadotropin and radioimmunoassay

    International Nuclear Information System (INIS)

    Okumura, Hajime; Sudo, Tadamitsu; Fujisawa, Munetoshi; Namba, Shuichi; Matsushima, Sanae

    1976-01-01

    A crude hCG with an activity of about 3,000 IU per mg was purified to 10,000-15,000 IU per mg of dry weight using Amberlite CG-50 chromatography combined with DEAE-Sephadex A-50 and Sephadex G-75. The alpha and beta subunits of hCG were prepared by urea-treatment of the hormone and were isolated by DEAE-Sephadex A-50 chromatography. Further purification of the subunits was achieved by gel filtration on a Sephadex G-57 column. For radioimmunoassay, hCG was iodinated by the DMSO-chloramine T method. Iodination of hCG with non-radioactive iodine revealed that the addition of DMSO to the iodination mixture seemed to reduce the iodination damage to the antigenic activity of the hormone. The hCG iodinated with non-radioactive iodine (accomplished by the DMSO-chloramine T method) was 1.5 times more immunoreactive in the hCG radioimmunoassay then the hCG iodinated by the usual chloramine T method. The radioimmunoassay of the hCG-beta subunit developed in our laboratory was satisfactory with respect to specificity. The hLH, hFSH, hTSH and hCG-alpha subunits tested cross-reacted very poorly in our assay system. Desialylated-hCG and subunits, in which the biologic potency was almost zero, also exhibited decreased immunoreactivity, about 30% of the native hormone with grossly unimpaired parallelism in their respective homologous radioimmunoassays. The concentrations of hCG and the subunits were determined on human sera from pregnant patients. The hCG levels reached to a peak at the first trimester of the pregnancy, but the hCG-beta subunits varied poorly in their concentrations throughout the periods of pregnancy. The hCG-alpha levels, on the other hand, showed two distinct peaks, in the early period and at the term of pregnancy. (J.P.N.)

  16. Radioimmunoassay of serum β2-microglobulin in donor's blood

    International Nuclear Information System (INIS)

    Yin Shihua; Song Shiyun; Li Kelin; Chen Guanglian; Liu Fengmin

    1993-01-01

    Serum β 2 -microglobulin (β 2 -MG) was tested by radioimmunoassay in 149 donors' and 54 healthy volunteers' blood. The results were 203 +- 33.0 nmol/l and 176 +- 26.2 nmol/l, respectively. There was significant difference statistically between them (P 2 -MG content. In order to increase the quality of donated blood and to keep the health of blood donor, it is suggested that the high content of serum β 2 -MG is the indicator of too frequent blood donating. The results also showed that the content of β 2 -MG in donor's blood is not a normal reference value

  17. Chromatographic purification of tritiated steroids prior to use in radioimmunoassay

    International Nuclear Information System (INIS)

    Manlimos, F.S.; Abraham, G.E.

    1975-01-01

    The purity of tritiated steroids used as reagents in radioimmunoassay plays an important role in the reliability of the assay. These radioactive reagents should be assessed for purity upon receipt and the purity should be checked periodically afterward. For such purposes, we have used chromatographic purification on Celite microcolumns. By changing the polarity of the stationary and mobile phases, 20 different tritiated steroids with a wide range of polarity could be purified on these microcolumns. This approach is easy, rapid, economical, and reliable. (U.S.)

  18. 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 %

  19. Radioimmunoassay of somatostatin: methodological problems and physiological investigations

    International Nuclear Information System (INIS)

    Penman, E.; Wass, J.A.H.

    1981-01-01

    Somatostatin, a tetradecapeptide, has a wide distribution throughout the central nervous system and the gastrointestinal tract and a broad spectrum of biological actions. In order to investigate its various physiological roles in man, a radioimmunoassay was developed for somatostatin in human blood plasma, which is described here. This RIA was used to investigate possible factors influencing somatostatin secretion. Changes in somatin levels produced by changes in insulin, glucagon and growth hormone levels were studied via the response of plasma immunoreactive somatostatin to hormonal stimuli in normal man. The influence of fasting and food consumption was studied; and the site of origin of circulating immunoreactive somatostatin was investigated in patients. (Auth.)

  20. 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

  1. Radioimmunoassay of human muscle carbonic anhydrase III in dystrophic states

    International Nuclear Information System (INIS)

    Heath, R.; Jeffery, S.; Carter, N.

    1982-01-01

    A radioimmunoassay for the human isozyme carbonic anhydrase III (CAIII) has been developed. The assay can detect levels as low as 4μg/l of sample. Plasma CAIII levels in patients suffering from Duchenne muscular dystrophy were found to be up to 39 times greater than in a control group. Urine CAIII levels in patients suffering from Duchenne muscular dystrophy were not significantly different from the levels found in urine from normal adults. Measurement of plasma CAIII levels may be useful in prenatal diagnosis of Duchenne muscular dystrophy, and in investigation of adult skeletal muscle disease. (Auth.)

  2. Preparation and purification of 7-Iodoclonazepam for use in radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, C.P.; Law, B.; Mason, P.A.; Stead, A.H.

    1986-04-01

    A method is described for the preparation and purification of 7-(/sup 125/I)-Iodoclonazepam (5-(o-Chlorophenyl)-2,3-Dihydro-7-(/sup 125/I)-Iodo-1H-1,4-Benzodiazepin-2-one). The structure was confirmed by mass spectrometry using 7-(/sup 127/I)iodoclonazepam prepared by the same method. 7-(/sup 125/I)-Iodoclonazepam binds well to a benzodiazepine antiserum. Although readily displaced by all the benzodiazepines commercially available in the UK, it is not displaced by structurally related nonbenzodiazepines except at very high concentrations. 7-(/sup 125/I) Iodoclonazepam should therefore be useful for the development of a screening radioimmunoassay (RIA) for benzodiazepines.

  3. Studies on digoxin derivatives in different biological media by radioimmunoassay

    International Nuclear Information System (INIS)

    Barmasch, Martha; Perez, L.N.; Altschuler, Noe.

    1978-05-01

    The fundamental aim of this study was to develop a methodology to be applied to pharmacological studies, directed to demonstrate the passage of digitalic compounds through the blood-brain barrier. This study was a comparative one between β methyl digoxin (βMD) and digitoxin (Dt). A methodology of radioimmunoassay was developed for different biological media: serum (S), plasma (P) and cerebro spinal fluid (CSF). In addition, the immunochemical behaviour (affinity, displacement, etc.) of βMD was studied when reacted with digoxin (D) and digoxin-antisera, supplied by the commercial kits utilized in these studies. (author) [es

  4. Radioimmunoassay test system for detection of anti-insulin antibodies

    International Nuclear Information System (INIS)

    Dudko, N.V.; Piven', N.V.; Ibragimova, G.V.; Kasatkin, Yu.N.

    1995-01-01

    A radiodiagnostic test system has been developed and commercial kit for radioimmunoassay of anti-insulin antibodies in human blood serum created. Clinical trials of the kit in patients (150 diabetics with types 1 and 2 condition) and normal subjects (n=100) demonstrated the possibility of using this kit for the detection of preclinical forms of diabetes and for distinguishing groups at risk of diabetes among children and adults, for the detection of insulin resistance, for the differential diagnosis of diabetes, and for monitoring the efficacy of insulin therapy. 9 refs.; 1 tab

  5. 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

  6. Radioimmunoassay and radioenzymatic assay of a new aminoglycoside antibiotic, netilmicin

    International Nuclear Information System (INIS)

    Broughton, A.; Strong, J.E.; Pickering, L.K.; Knight, J.; Bodey, G.P.

    1978-01-01

    A radioimmunoassay and a radioenzymatic assay for netilmicin, a new aminoglycoside, were developed in our laboratories to assist in the study of the pharmacology of the drug and establish values for use in its monitoring. The assays are sensitive, precise, and rapid, giving results that correlate (r = 0.90) with each other and with those of a microbiological assay in which Klebsiella pneumoniae is used as the test organism. Preliminary pharmacological studies show the drug to have a biological half-life of 135 min, which is comparable to that for other aminoglycosides

  7. Radioimmunoassay of total testosterone in urine of men

    International Nuclear Information System (INIS)

    Bilek, R.; Chundela, B.; Hampl, R.; Starka, L.

    1985-01-01

    The results are described and evaluated of the radioimmunoas radioimmunoassay of total testosterone in the urine in a sample of five men of the ages between 18 and 21 years. The levels of testosterone were related to creatinine in the urine in order to eliminate the effect of urine dilution. The analysis of the results showed that there exists a statistical difference between the levels of total testosterone related to creatinine in dependence on the time of sampling. The average value with standard deviation of total testosterone was 109 +- 41 ng testosterone/1 ml urine, 24.07 +- 8.33 pmol testosterone/1 μmol creatinine. (author)

  8. Comparison of radioimmunoassay and gas chromatographic mass spectrometric assay for d-amphetamine

    International Nuclear Information System (INIS)

    Powers, K.H.; Ebert, M.H.

    1979-01-01

    Quantification of low levels of psychotropic drugs (10 -7 to 10 -9 g ml -1 ) in small volumes of plasma requires sensitive and accurate methods. Validation of these methods is best achieved by comparing results obtained using several techniques. In this study, amphetamine levels in plasma were measured using gas chromatography mass spectrometry and radioimmunoassay. Correlation of the results obtained by the two methods was found to be positive and high (R = 0.9822). The average coefficient of variation between assays for gas chromatography mass spectrometry was 5.8% and for radioimmunoassay was 12.3%, while the average coefficient of variation within assays for gas chromatography mass spectrometry was 4.9% and for radioimmunoassay 6.9%. Although gas chromatography mass spectrometry was 1.9 times more sensitive than radioimmunoassay, for most purposes, the convenience of the radioimmunoassay method outweighs the technical superiority of gas chromatography mass spectrometry. (author)

  9. 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

  10. The development of a general solid-phase radioimmunoassay method. Application to follicle stimulating hormone and to luteinizing hormone radioimmunoassays

    International Nuclear Information System (INIS)

    Fleury, B.

    1981-10-01

    A solid phase method of radioimmunoassay utilizing a second antibody adsorbed onto tubes was developed. Polyethylene tubes were selected for their adsorption capacity. The following topics were emphasized: the rate of labelled antigen uptake on the second antibody adsorbed on the tubes through the medium of the first antibody; the influence of the second antibody on the antigen-first antibody reaction and comparison with the immunoprecipiting technique; the various factors able to influence the calibration curve and applications to assay optimization; the performances of hFSH AND hLH assays [fr

  11. The Decay of Wooden Wreck at Two Sites in Dubrovnik Area

    OpenAIRE

    Bego, Margarita; Bratoš Cetinić, Ana; Španić, Nikola

    2014-01-01

    The preparation is presented of underwater wood, wood identification, wood properties and FT-IR analysis. Two samples of Oak (Quercus petraea Liebl.; Quercus robur L.) were analyzed from two sites in Dubrovnik area, island Koločep and Molunat. This paper presents the preparation of underwater wood, wood identification, wood roperties and FT-IR analysis. Three section of wood, cross section, radial section and tangential section made for microscopis hardwood and softwood identification. The be...

  12. Two-site Hubbard molecule with a spinless electron-positron pair

    KAUST Repository

    Cossu, Fabrizio

    2012-12-19

    We determine the eigenvalues of the two-site Hubbard molecule with one electron and one positron to describe the characteristics of electron-positron interactions in solids. While the effect of hopping is, in general, opposite to the effect of on-site interaction, we find a complex scenario for the electron-positron pair with a non-vanishing potential drop. We give analytical solutions and discuss the combined effects of the model parameters.

  13. A specific and sensitive radioimmunoassay for human choriogonadotropin

    International Nuclear Information System (INIS)

    Muralidhar, K.; Chaudhuri, G.; Lippes, J.; Bahl, O.P.

    1983-01-01

    A specific and sensitive radioimmunoassay for human choriogonadotropin (hCG) has been developed using rabbit antiserum to chemical analogs of beta subunit of human chorionic gonadotropin prepared by controlled reduction and S-alkylation of its disulfied linkages. The assay was highly specific for hCG as the binding of [ 125 1]-hCG to the antibody was not affected by standard human lutropin, by human male serum, postpartum serum from women, serum from post-menopausal women and human menopausal gonadotropin (Pergonal). The assay was highly sensitive, the minimal detection limit in terms of highly purified hCG (L-129, 12.500 IU/mg) being 1 ng/ml or 0.2 ng/tube (or 12 mlU/ml in terms of WHO 2nd international reference preparation of hCG). Using this assay we were unable to detect any immunoreactive hCG in human tissues like lung, liver and colon. The high specificity, sensitivity, accuracy and reproducibility of the assay make this a highly desirable radioimmunoassay for human choriogonadotropin. (orig.)

  14. Secretin-radioimmunoassay, physiology and pathophysiology in man

    International Nuclear Information System (INIS)

    Haecki, W.H.

    1978-01-01

    Production of antibodies to secretin for radioimmunoassay is straightforward. Secretin is iodinated by weak oxydation with lactoperoxydase and subsequent purification by ionexchange chromatography (Sephadex C25). The specific activity of fresh label is between 650 and 900 mCi x mol -6 . The label is highly purified and may be used in radioimmunoassay for several months. In order to eliminate plasma interference sepharose-beads with covalently coupled secretin antibodies are used to produce secretin-free standard plasma samples. Delay in the separation of plasma from fresh blood samples can lead to erronous results, even to falsely elevated secretin levels. - Duo-denal acidification only leads to physiological increases of secretin plasma levels. This may happen by intraduodenal instillation of acid, or by an acidic oral drink, or to a lesser extent after a meal. Secretin is distributed throughout the plasma volume and has a short halflife of around 3 minutes. Impaired release of secretin is found in children with coeliac disease. The role of secretin in peptic ulcer however is not clear. Chronic pancreatitis and renal insufficiency are without effect on plasma secretin levels. (orig.) [de

  15. 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

  16. 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

  17. Radioimmunoassay of chorionic gonadotropin in the diagnosis of ectopic pregnancy

    International Nuclear Information System (INIS)

    Skalba, P.; Grochal, A.; Kokocinska, D.; Parylak, H.

    1977-01-01

    The applicability of radioimmunoassay of the chorionic gonadotropins (HCG) was studied considering the diagnosis of ectopic pregnancy. The radioimmunoassay technique was presented basing on personal anti HCG serum and HCG preparation (Serono). The technique of separation, based on solid phase was described. The technique is not fully specific, permits, nevertheless to determine the serum hormone concentrations ranging over 0.4 μg per ml. The investigations were carried in 26 cases to tubal pregnancy and in 22 unpregnant women - where basing on the initial diagnosis and clinical observations, ectopic pregnancy was suspected. Moreover the serum HCG was established in 64 women in recent intrauterine pregnancy - lasting 3 to 8 weeks. The mean serum HCG concentration in cases of ectopic pregnancy was 5.4 μg per ml and was significantly lower than in cases of 4 weeks lasting intrauterine gestation. The presence of HCG was demonstrated in all cases of real ectopic gestations, it was absent in the compared group of the suspected, but unpregnant, subjects. The paper suggests that the presented method can be applied for the differential diagnosis of ectopic pregnancy and permits to plan the further clinical procedures. (author)

  18. Radioimmunoassay for mammalian type C viral reverse transcriptase

    International Nuclear Information System (INIS)

    Krakower, J.M.; Barbacid, M.; Aaronson, S.A.

    1977-01-01

    Radioimmunological techniques were applied to the analysis of reverse transcriptases of mammalian type C RNA viruses. The polymerase of Rauscher mouse leukemia virus was purified by ion exchange and sequential affinity chromatography. Radioimmunoassays that utilized the viral enzyme as a probe detected as little as 1 ng of purified polymerase. No cross-reactivity could be demonstrated between the reverse transcriptase and other known virus-coded proteins. By comparing the immunological reactivity of the purified enzyme with the reactivity of detergent-disrupted virions, Rauscher mouse leukemia virus was shown to contain the antigenic equivalent of 40 molecules of reverse transcriptase. In a homologous competition immunoassay, the Rauscher viral enzyme demonstrated type-specific antigenic determinants, which distinguish it from other mouse type C viral polymerases. In a broadly reactive interspecies immunoassay, the reverse transcriptases of a number of mammalian type C viruses were cross-reactive, indicating their shared antigenic determinants. Various treatments that inhibited or inactivated DNA polymerase activity had little or no effect on the immunological properties of the enzyme. Thus, radioimmunoassays should be useful in the search for type C viral reverse transcriptase as a marker of subviral expression

  19. Damage Tolerance Characterization of Sandwich Composites Using Response Surfaces

    National Research Council Canada - National Science Library

    Lacy, T

    2002-01-01

    The influence of material configuration and impact parameters on the damage tolerance characteristics of sandwich composites comprised of carbon-epoxy woven fabric facesheets and Nomex honeycomb cores...

  20. Damage Tolerance of Resin Transfer Molded Composite Sandwich Constructions

    National Research Council Canada - National Science Library

    Vaidya, U

    1999-01-01

    .... The sandwich composite concepts considered in this study possessed the feasibility to improve the transverse stiffness, provide enhanced damage resistance/tolerance to impact and functionality...

  1. An evaluation of a two-site pilot model for dental foundation training.

    Science.gov (United States)

    Ali, K; Khan, S; Briggs, P; Jones, E

    2017-08-25

    Objectives To evaluate the feasibility, strengths, weaknesses, and challenges of a two-site model of dental foundation training.Methods A mixed methods approach was used to evaluate the two-site pilot. Qualitative interviews and focus groups were employed to gain an in-depth understanding of the expectations, experiences and concerns of the stakeholders. Additionally, purposefully designed questionnaires were used to rate different elements of the training.Results Participants included 12 foundation dentists, 15 educational supervisors and seven assistant educational supervisors. An increased breadth of clinical experience, a more variable case-mix, feedback from two teams of supervisors, and the experience of working within two different practices with two different teams and cultures were perceived to be the main strengths. The key challenges reported by the trainers were increased workload, a perceived disruption to the continuity of patient-care and perceived difficulties in establishing professional relationships.Conclusions This paper reports on the evaluation of a new model of dental foundation training in London. It highlights potential advantages and drawbacks of providing dental foundation training in two dental practices. Given the limitations of the of evaluation reported in this paper, additional work is required to establish the feasibility and effectiveness of the two-site training model.

  2. A double-sandwich ELISA for identification of monoclonal antibodies suitable for sandwich immunoassays

    Science.gov (United States)

    The sandwich immunoassay (sIA) is an invaluable technique for concentrating, detecting, and quantifying target antigens. The two critical components required are a capture antibody and a detection antibody, each binding a different epitope on the target antigen. The specific antibodies incorporated...

  3. Impact response of balsa core sandwiches

    Directory of Open Access Journals (Sweden)

    Nurdane Mortas

    2014-10-01

    Full Text Available The benefits of resins nano-enhanced on the impact response of sandwich composites made by fiber glass/epoxy skins and balsa wood core were studied. Afterwards, the influence of the core's discontinuity was analyzed in terms of impact strength. For better dispersion and interface adhesion matrix/clay nanoclays were previously subjected to a silane treatment appropriate to the epoxy resin. Resins enhanced by nanoclays promote higher maximum impact loads, lower displacements and the best performance in terms of elastic recuperation. The core's discontinuity decreases the impact strength, but the resin enhanced by nanoclays promotes significant benefits.

  4. Nurse managers and the sandwich support model.

    Science.gov (United States)

    Chisengantambu, Christine; Robinson, Guy M; Evans, Nina

    2018-03-01

    To explore the interplay between the work of nurse managers and the support they receive and provide. Support is the cornerstone of management practices and is pivotal in employees feeling committed to an organisation. Support for nurse managers is integral to effective health sector management; its characteristics merit more attention. The experiences of 15 nurse managers in rural health institutions in South Australia were explored using structured interviews, observation and document review. Effective decision making requires adequate support, which influences the perceptions and performance of nurse managers, creating an environment in which they feel appreciated and valued. An ideal support system is proposed, the "sandwich support model," to promote effective functioning and desirable patient outcomes via support "from above" and "from below." The need to support nurse managers effectively is crucial to how they function. The sandwich support model can improve management practices, more effectively assisting nurse managers. Organisations should revisit and strengthen support processes for nurse managers to maximize efficiencies. This paper contributes to understanding the importance of supporting nurse managers, identifying the processes used and the type of support offered. It highlights challenges and issues affecting support practices within the health sector. © 2017 John Wiley & Sons Ltd.

  5. Dynamic Failure of Composite and Sandwich Structures

    CERN Document Server

    Abrate, Serge; Rajapakse, Yapa D S

    2013-01-01

    This book presents a broad view of the current state of the art regarding the dynamic response of composite and sandwich structures subjected to impacts and explosions. Each chapter combines a thorough assessment of the literature with original contributions made by the authors.  The first section deals with fluid-structure interactions in marine structures.  The first chapter focuses on hull slamming and particularly cases in which the deformation of the structure affects the motion of the fluid during the water entry of flexible hulls. Chapter 2 presents an extensive series of tests underwater and in the air to determine the effects of explosions on composite and sandwich structures.  Full-scale structures were subjected to significant explosive charges, and such results are extremely rare in the open literature.  Chapter 3 describes a simple geometrical theory of diffraction for describing the interaction of an underwater blast wave with submerged structures. The second section addresses the problem of...

  6. Modeling of Sandwich Sheets with Metallic Foam

    International Nuclear Information System (INIS)

    Mata, H.; Jorge, R. Natal; Fernandes, A. A.; Parente, M. P. L.; Santos, A.; Valente, R. A. F.

    2011-01-01

    World-wide vehicles safety experts agree that significant further reductions in fatalities and injuries can be achieved as a result of the use of new lightweight and energy absorbing materials. On this work, the authors present the development and evaluation of an innovative system able to perform reliable panels of sandwich sheets with metallic foam cores for industrial applications. The mathematical model used to describe the behavior of sandwich shells with metal cores foam is presented and some numerical examples are presented. In order to validate those results mechanical experiments are carried out. Using the crushable foam constitutive model, available on ABAQUS, a set of different mechanical tests were simulated. There are two variants of this model available on ABAQUS: the volumetric hardening model and the isotropic hardening model. As a first approximation we chose the isotropic hardening variant. The isotropic hardening model available uses a yield surface that is an ellipse centered at the origin in the p-q stress plane. Based on this constitutive model for the foam, numerical simulations of the tensile and bulge test will be conducted. The numerical results will be validated using the data obtained from the experimental results.

  7. Design Analysis of the Mixed Mode Bending Sandwich Specimen

    DEFF Research Database (Denmark)

    Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

    2010-01-01

    . The analysis facilitates selection of the appropriate geometry for the MMB sandwich specimen to promote debond failure. An experimental study is performed using MMB sandwich specimens with a H100 PVC foam core and E-glass–polyester faces. The results reveal that debond propagation is successfully achieved...

  8. Non-linear Behavior of Curved Sandwich Panels

    DEFF Research Database (Denmark)

    Berggreen, Carl Christian; Jolma, P.; Karjalainen, J. P.

    2003-01-01

    In this paper the non-linear behavior of curved sandwich panels is investigated both numerically and experimentally. Focus is on various aspects of finite element modeling and calculation procedures. A simply supported, singly curved, CFRP/PVC sandwich panel is analyzed under uniform pressure load...

  9. Optimization of sandwich composites fuselages under flight loads

    NARCIS (Netherlands)

    Yan, C.; Bergsma, O.; Koussios, S.; Zu, L.; Beukers, A.

    2010-01-01

    The sandwich composites fuselages appear to be a promising choice for the future aircrafts because of their structural efficiency and functional integration advantages. However, the design of sandwich composites is more complex than other structures because of many involved variables. In this paper,

  10. Application of Load Carrying Sandwich Elements in Wind Turbine Blades

    DEFF Research Database (Denmark)

    Jensen, Jacob Fisker; Schultz, Jacob Pagh; Berggreen, Carl Christian

    2005-01-01

    The present work investigates the possibilities and drawbacks when applying sandwich as opposed to single skin composites in the flanges of the load carrying spar in a future 180 m wind turbine rotor. FEA is applied to investigate two basic designs with single skin and sandwich flanges respectively...

  11. Measuring Cohesive Laws for Interfaces in Sandwich Structures

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Sørensen, Bent F.; Berggreen, Carl Christian

    2006-01-01

    mixities. The sandwich specimens consists of glass fiber faces and Divinycell H200 foam core with a pre-crack between face and core made with teflon film. Arbitrary stiffening of the sandwich faces with steel bars adhered to the faces reduces rotations and ensures that the method is useable for a wide...

  12. Open versus closed sandwich wound dressing method in burn ...

    African Journals Online (AJOL)

    Methods: A retrospective study was conducted on 170 children under 12years admitted to the Pediatric surgical/female burn ward between the months of June 2006 to March 2007. A comparison was made between the open and closed sandwich method of burn wound dressing. The sandwich method entailed using 17 by ...

  13. The sandwich sign | Mahomed | SA Journal of Radiology

    African Journals Online (AJOL)

    The sandwich sign refers to the sandwiching of mesenteric vessels and fat by enlarged mesenteric nodes on cross-sectional imaging, commonly occurring in lymphoma, but not specific to lymphoma. The sign is radiologically indistinguishable from post-transplant lymphoproliferative disorders. The radiological significance ...

  14. Design and manufacturing of bio-based sandwich structures

    CSIR Research Space (South Africa)

    John, Maya J

    2017-03-01

    Full Text Available techniques for manufacture of sandwich panels are documented in detail. Bio-based sandwich panels are prepared by using bio-based skins (either a natural fiber skin impregnated with a thermoset resin or biopolymer skin bonded to the core with adhesives...

  15. Residual bending behaviour of sandwich composites after impact

    NARCIS (Netherlands)

    Baran, Ismet; Weijermars, Wouter

    2018-01-01

    This work investigates the residual mechanical behaviour of composite sandwich panels in bending after impact loading conditions. The sandwich panels were made of an epoxy/glass face sheet with three different core materials: styrene acrylonitrile foam, polyethylene terephthalate foam and Balsa

  16. 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)

  17. 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

  18. 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

  19. Production of biological reagents for radioimmunoassay second antibody

    International Nuclear Information System (INIS)

    Borghi, V.C.; Silva, S.R. da; Bellini, M.H.; Lin, L.H.

    1992-02-01

    The experimental production of second antibody to be used in hormonal assays, in which the first antibody is raised in rabbits, is described. Four sheep were immunized with the rabbit immunoglobulin prepared at IPEN-CNEN laboratory. Their antisera were evaluated by the human thyrotropin radioimmunoassay employing materials provided by the National Hormone and Pituitary Program (USA), in comparison with a reference antiserum of known quality, produced in goat by the Radioassay Systems Laboratories - RSL (USA). From the fourth booster injection the animals developed antiserum with titer similar to that exhibited by the commercial product, even presenting higher values. These antisera are now being examinated for the optimal conditions of precipitation before be packed for future use and distribution. (author)

  20. Development of a heterologus radioimmunoassay for human prolactin (hprl)

    International Nuclear Information System (INIS)

    Kothari, K.K.; Meera, V.; Soman, P.D.; Lal, R.; Sivaprasad, N.

    1991-01-01

    The development of a heterologous radioimmunoassay for the measurement of human prolactin in serum is reported. The assay uses the less expensive ovine prolactin for the preparation of 125 I labelled prolactin and anti prolactin serum while the human prolactin in used as standard. The assay is based on a double antibody- polyethylene glycol separation system for the separation of the antibody bound antigen from the free antigen. The optimized assay has a preincubation of the antibody with the cold antigen for 18 hours followed by a post incubation of 3 hours with the tracer. The sensitivity of this assay is 2ng/mL. The inter and intra assay variations are less than 9%. The values of the serum samples analysed by this method compares well with immunoradiometric assay. (author). 12 refs. , 6 figs., 2 tabs

  1. Development and characterization of a homologous radioimmunoassay for equine prolactin

    International Nuclear Information System (INIS)

    Roser, J.F.; Chang, Y.S.; Papkoff, H.; Li, C.H.

    1984-01-01

    A specific and sensitive homologous radioimmunoassay has been developed for equine prolactin, suitable for measuring prolactin concentrations in serum of horses. The sensitivity of the assay ranged from 0.4 to 0.6 ng/ml and the intra- and inter-assay coefficients of variation averaged 6.9 and 15.4%, respectively, for five doses of hormone. Cross-reactivity with other mammalian and nonmammalian prolactins and growth hormones was less than 20 and 0.3%, respectively. Cross-reactivity with equine growth hormone was less than 0.07%. Equine serum and pituitary extracts showed parallel dilution-response curves with equine prolactin. The percentage recovery of exogenous equine prolactin in serum was 89%. Preliminary analysis of several physiological samples (stallions, pregnant, and nonpregnant mares) yielded values from 0.6 to 12.0 ng/ml

  2. The milk samples collected with filter paper for progesterone radioimmunoassay

    International Nuclear Information System (INIS)

    Zhang Jiahua; Geng Guoxia; Zhang Huaiyu

    1985-01-01

    The cow milk was collected with filter paper treated with ethanol during eastrus-day (0 day) and 22th and 24th day after mating. Then it was dried and stored in room temprature until analysis for progesterone by means of radioimmunoassay. The sensitivity is 13.62 pg/bule (n = 4), the coefficients of variation within a group and between groups are 8.8% (n = 10) and 16.65% (n = 8) respectively, and the recovery is 91.23% (n = 4). The average progesterone level for 22th and 24th day in the pregnant cows (6.28 +- 1.28 ng/ml) was much higher than that in the non-pregnant cow (2.00 +- 1.18 ng/ml), the difference being significant (P < 0.001). The judgement based on progesterone level (5 pregnant and 5 non-pregnant cows) faily agreed with the clinical diagnosis

  3. Farm application of radioimmunoassay technology in dairy cattle management

    International Nuclear Information System (INIS)

    Alejandrino, A.L.; Asaad, C.O.; De Vera, A.C.; Deocaris, C.C.; Ignacio, L.M.; Herrera, M.S.; Mateo, A.B.

    1996-01-01

    Monitoring of progesterone concentrations in milk or blood plasma of farm animals, using radioimmunoassay technology is presented in this report. This was instituted among 103 dairy cows managed by dairy cooperatives under smallholder level in Sta. Cruz-Pagsanjan, Laguna and Sariaya, Quezon (n=103), and under communal level Pontevedra, Capiz (n=48). The authors observed that the measurement of progesterone in milk/plasma was proven useful as a diagnotic aid in dairy cattle production studies such as: (a) early pregnancy diagnosis; (b) identification of fertile and abnormally cycling/subestrus or anestrous cows, and (c) appropriate timing for breeding services especially at post-partum stage. This information is relevant where appropriate management intervention measures are indicated to improve dairy cattle production in the country. (author)

  4. Radioimmunoassay data processing program for IBM PC computers

    International Nuclear Information System (INIS)

    1989-06-01

    The Medical Applications Section of the International Atomic Energy Agency (IAEA) has previously developed several programs for use on the Hewlett-Packard HP-41C programmable calculator to facilitate better quality control in radioimmunoassay through improved data processing. The program described in this document is designed for off-line analysis using an IBM PC (or compatible) for counting data from standards and unknown specimens (i.e. for analysis of counting data previously recorded by a counter), together with internal quality control (IQC) data both within and between batch. The greater computing power of the IBM PC has enabled the imprecision profile and IQC control curves which were unavailable on the HP-41C version. It is intended that the program would make available good data processing capability to laboratories having limited financial resources and serious problems of quality control. 3 refs

  5. Provision of radioimmunoassays for reproductive hormones in developing countries

    International Nuclear Information System (INIS)

    Sufi, S.B.; Donaldson, A.; Jeffcoate, S.L.; Goncharov, N.P.

    1986-01-01

    The Special Programme of Research, Development and Research Training in Human Reproduction of the World Health Organization (WHO) has, for the last eight years, distributed sets of matched assay reagents for the radioimmunoassay of hormones to approximately 75 laboratories in 45 countries. The Matched Reagent Programme has enabled these centres to carry out research that would otherwise have been difficult, if not impossible, for them to undertake. Between-centre comparability, as judged by WHO External Quality Assurance Scheme data, has improved and at least five hundred scientific papers have been published as a consequence of the availability of WHO reagents. National and regional reagent programmes and associated schemes are being encouraged. These activities should help to improve the availability of research and diagnostic facilities for patient care in developing countries, which is consistent with the WHO policy of technology transfer. (author)

  6. Radioimmunoassay for chlorpromazine in plasma. [/sup 3/H tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Midha, K.K.; Loo, J.C.K.; Hubbard, J.W.; Rowe, M.L.; McGilveray, I.J.

    1979-01-01

    A radioimmunoassay for chlorpromazine in plasma is described. The antiserum was obtained by immunizing rabbits with a conjugate of bovine serum albumin and N-(2-carboxyethyl)desmethylchlorpromazine. It is specific for chlorpromazine and its minor active metabolite, N-desmethylchlorpromazine. Other known active or inactive chlorpromazine metabolites and other psychotropic drugs tested do not cross react with the antiserum. Less than 34 pg of the drug can be detected in 200 ..mu..L of plasma. As many as 100 samples can be processed in a day by one technician. Concentrations of chlorpromazine can be measured in 200-..mu..L samples of plasma collected as late as 48 h after a single oral 25-mg dose.

  7. Radioimmunoassay for human plasma 8-arginine-vasopressin

    International Nuclear Information System (INIS)

    Conte-Devolx, B.; Rougon-Rapuzzi, G.; Millet, Y.

    1977-01-01

    A radioimmunoassay for human plasma vasopressin (AVP) which permits the estimation of antidiuretic hormone (ADH) level as low as 0.8pg/ml, was developed. The average plasma level of AVP after overnight water restriction was found to be 14.3pg/ml (sd=4.4pg/ml) in normal subjects. They provoked a hypersecretion of ADH by the intravenous injection of 1-2mg of nicotine. In 11 volunteer normal subjects this stimulation by nicotine provoked ADH hypersecretion which reached a maximum between 2nd and 15th minutes after injection. In 3 cases of diabetes insipidus, nicotine injection did not induce ADH hypersecretion: in 1 case of potomania this response was weak; in 2 cases of syndrome of inappropriate ADH secretion, AVP plasma levels were elevated and the response after nicotine stimulation was exaggerated [fr

  8. 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

  9. Measurement of plasma canine C peptide by radioimmunoassay

    International Nuclear Information System (INIS)

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

    1985-01-01

    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. (author)

  10. Production of Anti-triiodothyronine sulfate antibody for radioimmunoassay applications

    International Nuclear Information System (INIS)

    Elbanna, I.M.; Ragab, M.T.

    2000-01-01

    Triiodothyronine sulfate (T3S) may be an obligatory intermediate metabolic of the metabolism of thyroid gland hormones invertebrates in peripheral during the process of deiodination of the inactive form of the thyroid gland hormones, thyroxine(T4), into the active form triiodothyronine (1,2). Construction of a reliable procedure for the estimation of T3S accurately in blood serum will be of great importance for medical, biochemical and physiological investigations. In this work we developed a robust method for the production of anti-triiodothyronine sulfate polyclonal antiserum with good specifications using a derivatized immuno gen and a modified immunization process and a sensitive radioimmunoassay system was designed and developed

  11. The measurement of platelet activation by radioimmunoassay in asthma

    International Nuclear Information System (INIS)

    Wu Guoxin; Sun Jian; Li Jianyong; Ruan Changgeng

    1992-02-01

    Radioimmunoassay with specific monoclonal antibody was used to evaluate the platelet activation in 14 cases of acute bronchial asthma. The result showed that the number of molecules of alpha-granule membrane protein (GMP-140) which was exposed on the surface of platelet following secretion significantly increased on the surface of platelet and in plasma, while the number of molecules of glycoprotein (GP) I b and GPIII a did not change significantly; the concentration of thromboxane B 2 in plasma was raised, while the concentration of 6-keto-PGF 1a was within the normal limits; the concentrations of β-thromboglobulin (β-TG) and platelet factor 4(PF 4 ) in plasma increased significantly; the number of platelets decreased. These results strongly confirmed that the degree of platelet activation was enhanced during acute asthmatic attack. The significance of platelet activation in the pathogenesis of asthma should be further investigated

  12. 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.

  13. An improved radioimmunoassay for urinary Tamm-Horsfall glycoprotein

    International Nuclear Information System (INIS)

    Dawnay, A.B. St. J.; Thornley, C.; Cattell, W.R.

    1982-01-01

    A rapid specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine, and the method described. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4 0 C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24h, (considerably higher than the amount present in serum) based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance. (author)

  14. Recombinant-derived chicken growth hormone used for radioimmunoassay

    International Nuclear Information System (INIS)

    Proudman, J.A.

    1984-01-01

    The use of recombinant-derived chicken growth hormone (rcGH) in an avian growth hormone (GH) radioimmunoassay (RIA) procedure is described. Antiserum to turkey GH bound 125 I-labeled rcGH, and unlabeled rcGH or turkey GH displaced binding in a dose-related manner. The dose-response curves of sera and pituitary extract from chickens and turkeys were parallel to the rcGH standard curve. Sera from hypophysectomized (hypox) chickens and turkeys produced no dose-response and did not inhibit binding of labeled rcGH. Recovery of rcGH added to hypox sera was quantitative. Modification of the homologous turkey GH RIA protocol of Proudman and Wentworth (1) to use rcGH made possible either an increase in assay sensitivity or a 3-day reduction in incubation time

  15. High molecular somatostatin, an interfering factor in radioimmunoassay

    International Nuclear Information System (INIS)

    Diel, F.; Schneider, E.; Baumann, H.

    1977-01-01

    Cyclic Tyr 1 -somatostatin (Tyr 1 -SRIF) is radioiodinated by the lactoperoxidase method. Purification is achieved by Sephadex G-25 adsorption chromatography. Specific anti-SRIF serum (FA1) has been raised in rabbits. A dose response curve is obtained in the range of 5 - 5,000 pg per tube using an antiserum dilution of 1:2,000. There is little cross-reaction with linear somatostatin and none with ocytocin, (lys-, arg-) vasopressin, valinomycin, polymyxin, insulin, glucagon, human growth hormone (hGH), and thyrotropin-releasing hormone (TRH). For recovery tests, extraction procedures are necessary. Thin-layer chromatography (TLC) and polyacrylamide-disc-electrophoresis (Disc-PAGE) are performed to identify the presumed high molecular 125 I-Tyr 1 -SRIF associate. This high molecular associate may represent an interfering factor in the radioimmunoassay for cyclic SRIF. (orig./AJ) [de

  16. Engineering of radioimmunoassay (RIA) IP10.1

    International Nuclear Information System (INIS)

    Hari Nurcahyadi

    2010-01-01

    Engineering of Radioimmunoassay (RIA) IP10.1 is an innovative by PRPN - BATAN in 2010. Innovations made to the device IP10.1 RIA is the sample changer system, sample changer system on the device RIA IP10.1 applied 2 linear axis system (X, Z) with AC servo motor. In the RIA IP10.1 also use 5 pieces of the detector, so the enumeration process 50 (Fifty) sample is expected to be faster. Like its predecessor, The whole enumeration, data collection procedures and mechanisms operating within this system is entirely controlled by a PC via an electronic module. Electronics module consists of a high voltage module, amplifier and signal processor module, the module enumerators, low-voltage module, the module driver motor controller and a USB interface. The data acquisition and communication system using a USB port with the computer. (author)

  17. Radioimmunoassay for phencyclidine: application to kinetic analysis in the rat

    International Nuclear Information System (INIS)

    Ward, D.P.; Trevor, A.J.

    1980-01-01

    We report the development of a radioimmunoassay for phencyclidine (PCP) that is simple, rapid and sensitive to 0.5 ng/ml. Antibodies were raised in rabbits against the hapten, N-succinyl-3-aminophencyclidine. These antibodies proved to be very specific for PCP and exhibited less than 4% cross reactivity with the drug's two major metabolites. The assay was used for kinetic analysis of PCP in the rat following subcutaneous injection of 5 mg/kg of the drug. Serum and brain tissues were analyzed for PCP and the respective half lives were calculated to be 36 and 29 min for the α phase and 130 and 121 min for the β phase. The accuracy of the method was verified by concomitant assay of a number of kinetic samples by gas chromatography employing a nitrogen-phosphorus detector

  18. 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

  19. Effect of radioimmunoassay procedures on therapeutic drug monitoring

    International Nuclear Information System (INIS)

    Kampa, I.S.

    1985-01-01

    Methods for the measurement of therapeutic drugs have covered every aspect of analysis from extraction to derivatization. In general, published methods were modified to shorten drug extractions and overall analysis time. The use of different standards, as well as the frequent omission of internal standards, often produced large and clinically unacceptable analytical variations. As a result, physicians would adjust drug dosages according to the physiological response to a standard dose. The introduction of radioimmunoassay techniques for the quantitation of therapeutic drugs have made a significant impact on the clinical chemistry laboratory. The similarities of the various assay methods and the technologists' familiarity with the assay protocols have produced clinically relevant results. Clinical laboratories are now able to frequently analyze a large number of samples with acceptable accuracy and precision. The esoteric test once performed infrequently is today a routine analytical assay often performed STAT. Therapeutic drug monitoring has become a major activity in many clinical laboratories

  20. Development of a radioimmunoassay for triamcinolone acetonide in horse plasma

    International Nuclear Information System (INIS)

    Gylstorff, B.

    1982-01-01

    A radioimmunoassay (RIA) was developed for the detection of triamcinolone acetonide (TAAc) in equine blood plasma. These antibodies exhibited cross reactions of 0,015% with cortisol and of 0,1% with other endogenous glucocorticoids. Four different synthetic corticosteroids interfered in a range of 0,21 to 0,93%. In vitro 86 of TAAc could be recovered. This method proved sufficient reproducibility down to a limit of 131,7 fmol/ml = 57,2 pg/ml. The TAAc RIA is suitable for the detection of a TAAc application particularly during the 1st day p.i. The results may obtain a higher limit of confidence by the simultaneous demonstration of cortisol suppression. By the use of this test more detailed conclusions may be drawn about presence and duration of a pharmacodynamic action originating from the TAAc depot. (orig./TRV) [de

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

    International Nuclear Information System (INIS)

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

    1984-01-01

    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 β-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

  2. Radioimmunoassay of aldosterone and its level in plasma and urine

    International Nuclear Information System (INIS)

    Putz, Z.; Hampl, R.; Veleminsky, J.; Starka, L.

    1981-01-01

    A method of plasma and urine aldosterone radioimmunoassay is described and evaluated. Highly specific antisera were obtained through rabbit immunization using partly aldosterone-18,21-dihemisuccinate-BSA, partly aldosterone-3-carboxymethyl-oxime-BSA, free of the 18-derivative. The use of a more specific antiserum against the 3-derivative permitted the determination to be performed immediately from the biological specimen extract. Hydrolysis with sulphuric acid in the presence of dichloromethane proved the most appropriate of the different techniques of releasing aldosterone-glucuronoside for the determination of the total urine hormone. The normal values (average +- 2 S. D.) of plasma aldosterone were 0.19 +- 0.067 nmol/l, those of the free urine hormone 0.918 +- 0.458 nmol/day, and the total urine aldosterone 15.3 +- 5.8 nmol/day. (author)

  3. Failure mechanism of PMI foam core sandwich beam in bending

    Directory of Open Access Journals (Sweden)

    Wang Bo

    2015-01-01

    Full Text Available Polymethacrylimide (PMI foams have been widely applied in aerospace engineering as the core material of sandwich structures. This paper proposes a modified model to predict the constitutive relation of PMI foams and compares it to existing testing data. The study is then applied to the investigation of the failure mechanism of PMI foam core sandwich beams in bending. Corresponding bending tests were carried out where a complex failure process was observed through a high-speed camera. Numerical model of the foregoing sandwich beam is developed, in which the maximum principal stress criteria is used to predict damage propagation in PMI foam core. Both results from tests and numerical simulation validate the reliability of the theoretical prediction of the failure of PMI foam core sandwich beam using the proposed modified model of PMI foams. This study provides a theoretic tool for the design of sandwich structures with PMI foam core.

  4. 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

  5. Hyperglucagonaemia analysed by glucagon sandwich ELISA

    DEFF Research Database (Denmark)

    Albrechtsen, Nicolai Jacob Wewer; Hartmann, Bolette; Veedfald, Simon

    2014-01-01

    after RYGB were from a study by Bojsen-Møller et al (trial registration number NCT 01202526). Samples from vagotomised and control individuals were from a study by Plamboeck et al (NCT01176890). Samples from ESRD patients were from a study by Idorn et al (NCT01327378)....... the extent to which the hyperglucagonaemia measured in clinical samples was caused by authentic glucagon. METHODS: We examined the performance of three commercial glucagon 'sandwich' ELISAs. The ELISA with the best overall performance was selected to compare glucagon measurements in clinical samples...... with an established glucagon RIA. RESULTS: The first assay performed poorly: there was high cross-reactivity with glicentin (22%) and a lack of sensitivity for glucagon. The second and third assays showed minor cross-reactivity (1-5%) with oxyntomodulin and glicentin; however, the second assay had insufficient...

  6. Standard Test Method for Sandwich Corrosion Test

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method defines the procedure for evaluating the corrosivity of aircraft maintenance chemicals, when present between faying surfaces (sandwich) of aluminum alloys commonly used for aircraft structures. This test method is intended to be used in the qualification and approval of compounds employed in aircraft maintenance operations. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information. 1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements appear in Section 9.

  7. TETHERED-BEAD, IMMUNE SANDWICH ASSAY

    Science.gov (United States)

    Silver, Jonathan; Li, Zhenyu; Neuman, Keir

    2014-01-01

    We describe a proof-of-principal, immune sandwich assay in which immune complexes link micron-size beads via DNA tethers to a sensor surface. The number of tethered beads, counted using low-magnification microscopy, provides a measure of the concentration of analyte. The prototype assay was sensitive to pM concentration of analyte. In theory, the assay could be sensitive to sub-fM analyte because beads attached via single-immune complexes and DNA strands form tethers, and tether formation in the absence of analyte is extremely rare. The limiting step at present is binding of streptavidin at the end of DNA to biotin on capture beads. Potential advantages of this type of sensor are discussed. PMID:25064819

  8. The use of diatomite microcolumns for the chromatographic separation of steroids prior to radioimmunoassay

    International Nuclear Information System (INIS)

    Abraham, G.E.

    1975-01-01

    Since most anti-steroid antibodies are not usually specific enough to permit direct radioimmunoassay of these compounds, chromatographic purification is required to achieve reliability Celite microcolumns were used for the separation of a wide range of steroids prior to radioimmunoassay. Depending on the polarity of the steroids to be separated, various mixtures of solvents are used as stationary and mobile phases. This system is rapid, easy, economical and reliable

  9. Miniaturized technique for the rapid extraction of plasma glucagon for radioimmunoassay

    International Nuclear Information System (INIS)

    Flatt, P.R.

    1981-01-01

    Radioimmunoassay of glucagon is hampered by interference from non-specific factors introduced into the incubation mixture by the plasma sample. The proteolytic destruction of glucagon must be minimized by using proteolytic enzyme inhibitors or plasma extraction techniques. The present report, which describes a miniaturized technique for the quantitative extraction of glucagon from plasma, is aimed at increasing the popularity of this approach to the plasma glucagon radioimmunoassay. (Auth.)

  10. 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)

  11. Epitope mapping of the carcinoembryonic antigen by monoclonal antibodies and establishment of a new improved radioimmunoassay system

    International Nuclear Information System (INIS)

    Kuroki, Masahide; Arakawa, Fumiko; Matsunaga, Akira; Okamoto, Naomi; Takakura, Kyoko; Matsuoka, Yuji; Higuchi, Hiroshi.

    1987-01-01

    A comprehensive mapping of epitopes on the carcinoembryonic antigen (CEA) molecule has been achieved by analyses of the specificities of 146 monoclonal antibodies (MAbs) from more than 300 hybridomas established recently. The reactivities of MAbs were analyzed by radio-immunoassays (RIA) with highly purified preparations of CEA and related antigens including normal fecal antigen-1 (NFA-1), NFA-2 in normal adult feces, nonspecific cross-reacting antigen (NCA) in lung and NCA-2 in meconium. The MAbs could be divided into five groups: group I, 23 clones directed to the NCA-common part of the CEA molecule; group II, 31 clones directed to the normal fecal cross-reacting antigen (NFCA)-common part; group III, 46 clones directed to the NFA-1-common part; group IV, 33 clones reactive with the heterogeneous carbohydrate part; and group V, 13 clones directed to the CEA-distinctive part which seemed to be highly specific for CEA. Mutual inhibitions of CEA binding between MAbs of the individual groups revealed that at least 25 different subgroups can be defined i.e., 4, 7, 8, 4, and 2 subgroups in groups I to V, respectively. The epitopes recognized by the group IV MAbs were found to be sensitive to oxidation with periodate, while the epitopes defined by MAbs of the other groups were resistant to this treatment. A solid-phase sandwich-type RIA system for CEA was established by using 2 MAbs from groups II and III as the CEA catcher and an MAb of group V as the tracer. This assay was shown to exhibit improved cancer-specificity and accuracy in the estimation of serum CEA levels. (author)

  12. Development and Mechanical Behavior of FML/Aluminium Foam Sandwiches

    Science.gov (United States)

    Baştürk, S. B.; Tanoğlu, M.

    2013-10-01

    In this study, the Fiber-Metal Laminates (FMLs) containing glass fiber reinforced polypropylene (GFPP) and aluminum (Al) sheet were consolidated with Al foam cores for preparing the sandwich panels. The aim of this article is the comparison of the flexural properties of FML/Al foam sandwich panels bonded with various surface modification approaches (silane treatment and combination of silane treatment with polypropylene (PP) based film addition). The FML/foam sandwich systems were fabricated by laminating the components in a mould at 200 °C under 1.5 MPa pressure. The energy absorbtion capacities and flexural mechanical properties of the prepared sandwich systems were evaluated by mechanical tests. Experiments were performed on samples of varying foam thicknesses (8, 20 and 30 mm). The bonding among the sandwich components were achieved by various surface modification techniques. The Al sheet/Al foam sandwiches were also consolidated by bonding the components with an epoxy adhesive to reveal the effect of GFPP on the flexural performance of the sandwich structures.

  13. Adiabatically modeling quantum gates with two-site Heisenberg spins chain: Noise vs interferometry

    Science.gov (United States)

    Jipdi, M. N.; Tchoffo, M.; Fai, L. C.

    2018-02-01

    We study the Landau Zener (LZ) dynamics of a two-site Heisenberg spin chain assisted with noise and focus on the implementation of logic gates via the resulting quantum interference. We present the evidence of the quantum interference phenomenon in triplet spin states and confirm that, three-level systems mimic Landau-Zener-Stückelberg (LZS) interferometers with occupancies dependent on the effective phase. It emerges that, the critical parameters tailoring the system are obtained for constructive interferences where the two sets of the chain are found to be maximally entangled. Our findings demonstrate that the enhancement of the magnetic field strength suppresses noise effects; consequently, the noise severely impacts the occurrence of quantum interference for weak magnetic fields while for strong fields, quantum interference subsists and allows the modeling of universal sets of quantum gates.

  14. Analytical diagonalization study of a two-orbital Hubbard model on a two-site molecule

    Energy Technology Data Exchange (ETDEWEB)

    Amendola, Maria Emilia, E-mail: canio@sa.infn.it [Dipartimento di Matematica, Università di Salerno, I-84084 Fisciano (Italy); Romano, Alfonso [CNR-SPIN, I-84084 Fisciano (Italy); Dipartimento di Fisica “E. R. Caianiello”, Università di Salerno, I-84084 Fisciano (Italy); Noce, Canio, E-mail: canio@sa.infn.it [CNR-SPIN, I-84084 Fisciano (Italy); Dipartimento di Fisica “E. R. Caianiello”, Università di Salerno, I-84084 Fisciano (Italy)

    2015-12-15

    We present the exact solution of a two-orbital Hubbard model on a two-site molecule for arbitrary electron filling and arbitrary interaction couplings. The knowledge of the many-particle spectrum, determined via a diagonalization procedure performed by fully taking into account the symmetry properties of the model, has been used to investigate the temperature dependence of charge, spin and orbital response functions as well as of the intra- and inter-orbital on-site occupations. We point out that this study may allow easy access to many interesting features of the model and may serve as a reference tool for various numerical or perturbation methods dealing with complex correlated electron models defined on a lattice, in particular in the case in which strong local interactions dominate over kinetic effects.

  15. A Ham Sandwich Is Better than Nothing: Some Thoughts about Transitivity

    Science.gov (United States)

    Roberts, Tim S.

    2004-01-01

    There is an old joke that says that given the choice between eternal happiness and a ham sandwich, one should choose the ham sandwich. The proof is quite simple: (1) nothing is better than eternal happiness; (2) a ham sandwich is better than nothing; and therefore, it straightforwardly follows from (1) and (2) that (3) a ham sandwich is better…

  16. Fracture Analysis of Debonded Sandwich Columns Under Axial Compression

    DEFF Research Database (Denmark)

    May, A.; Avilés, F.; Berggreen, Christian

    A sandwich structure consists of two strong and stiff face sheets bonded to a weak low density core. The large separation between the face sheets provides increased bending rigidity and strength at low weight cost. Thus, sandwich structures frequently present better mechanical properties than...... monolithic structures of the same weight. The vast range of applications of such materials includes wind turbines, marine, and aerospace industries. In this work, geometrically nonlinear finite element analysis is conducted to investigate the fracture parameters and debond propagation of sandwich columns...... containing a face-to-core debond subjected to axial compression. Bidimensional finite element models of sandwich columns containing different size debonds centered at one face/core interface were developed and used in conjunction with linear elastic fracture mechanics to predict the stress intensity factors...

  17. Boryl- and Silyl-Substituted Mixed Sandwich Compounds of Scandium.

    Science.gov (United States)

    Braunschweig, Holger; Damme, Alexander; Dück, Klaus; Krummenacher, Ivo; Paprocki, Valerie; Radacki, Krzysztof; Ramler, Jacqueline; Schiller, Carl; Schneider, Christoph

    2018-02-16

    An improved, one-pot synthesis of the linear sandwich compound [Sc(η 5 -C 5 H 5 )(η 8 -C 8 H 8 )] is presented. The synthetic procedure is amenable to boryl- and silyl-substituted cyclopentadienyl and cyclooctatetraenyl ligands, thereby yielding the first functionalized derivatives. We found that the synthesis of the silyl-substituted mixed sandwich complexes produces higher yields when the ligand exchange is carried out stepwise, by isolating the intermediate trimethylsilylated half-sandwich complex [Sc(η 8 -C 8 H 7 SiMe 3 )Cl(THF)] (THF=tetrahydrofuran). The molecular structures of the parent complex, as well as of its mono-boryl-substituted derivatives, have been determined by single-crystal X-ray diffraction. In addition, the optical and electrochemical properties of the mixed sandwich complexes are reported. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Three - Dimensional Dynamic Stress Analysis of Sandwich Panels

    National Research Council Canada - National Science Library

    Perel, Victor

    2000-01-01

    A layerwise geometrically nonlinear theory for a thick sandwich plate was developed by introducing assumptions on a variation of transverse strains in the thickness direction of the faces and the core of the plate...

  19. Half-sandwich ruthenium, rhodium and iridium complexes of ...

    Indian Academy of Sciences (India)

    sandwich ruthenium, rhodium and iridium complexes of triazolopyridine ligand: Synthesis and structural studies. NARASINGA RAO PALEPU RAO MOHAN KOLLIPARA. Regular Article Volume 129 Issue 2 February 2017 pp 177-184 ...

  20. Enhanced Performance of Sandwich Structures by Improved Damage Tolerance

    DEFF Research Database (Denmark)

    Martakos, Georgios

    up to about 200,000 load cycles, and to assess the effect of high cycle fatigue damage propagation was simulated up to about 2,000,000 load cycles. It was demonstrated that the developed computational methodology is capable of modelling the fatigue behaviour of sandwich structures with embedded peel...... behaviour around the new crack stopper elements. In support for the experimental investigations, a Finite Element (FE) analysis based methodology, including fracture mechanics analysis and the so-called ‘cycle jump’ technique, was developed to predict the progression of damage in sandwich specimens...... with embedded crack stoppers. The starting point for the research was is a new design for a crack stopper, referred to as a ‘peel stopper’, which is proposed for foam cored sandwich structures. Initially, the ability of the peel stopper to prolong the fatigue life of sandwich structures has been demonstrated...

  1. Experimental study of impact properties of aluminium honeycomb sandwich structure

    Directory of Open Access Journals (Sweden)

    Flasar Ondrej

    2017-01-01

    Full Text Available Aircraft grade of structural sandwich plates has been studied to determine the influence rate of particular face sheets adjustments on impact energy absorption. The face sheets were fabricated by carbon fibre reinforced plastic (CFRP laminas using unidirectional reinforcement with either cross-ply [0/90]n or angle-ply [±45]n orientation of fibres. A core of the sandwich plates was then formed by aluminium honeycomb. The impact properties of small unnotched sandwich specimens were measured by instrumented Charpy impact test device. Assessment of force-displacement curve, loading process and failure mode was carried out for each specimen type to determine a general trend for increasing the impact properties of sandwich structures.

  2. Mechanical and vibro-acoustic aspects of composite sandwich cylinders

    NARCIS (Netherlands)

    Yuan, C.

    2013-01-01

    Designing a fuselage involves many considerations such as strength and stability, fatigue, damage tolerance, fire and lightning resistance, thermal and acoustic insulation, production, inspection, maintenance and repair. In the background of the application of composite sandwich structures on the

  3. Experimental and numerical evaluation of viscoelastic sandwich beams

    Directory of Open Access Journals (Sweden)

    Waldir Neme Felippe Filho

    Full Text Available Abstract Viscoelastic materials can dissipate a large amount of energy when subjected to cyclic shear deformations, but they have low bearing capacity. Therefore they are often employed as a damping layer in sandwich structures. These sandwich structures present a high damping ratio and simple application. In order to design sandwich structures, many aspects ranging from computer modeling to laboratory testing should be considered. In this study, a test set of experiments were performed and results are compared with a numerical GHM (Golla, Hughes and Mc Tavish method based model, in order to establish a method to support viscoelastic sandwich beam design. In this way, starting from the dynamic properties of a viscoelastic material, a numerical model is used to evaluate the behavior of these structures. Comparisons with uncontrolled structures are also presented, showing the dissipative characteristics of this passive control.

  4. Smart FRP Composite Sandwich Bridge Decks in Cold Regions

    Science.gov (United States)

    2011-07-01

    In this study, new and integrated Smart honeycomb Fiber-Reinforced Polymer (S-FRP) : sandwich materials for various transportation construction applications, with particular emphasis : on highway bridge decks in cold regions, were developed and teste...

  5. PM2.5 Indoor Air Quality at Two Sites in London Ontario - A Case Study

    Science.gov (United States)

    Mates, A. V.; Xu, X.; Gilliland, J.; Maltby, M. J.

    2010-12-01

    Studies have shown an association between ambient fine particulate matter (PM2.5) and health impacts, particularly for the elderly and children. As part of a larger study, PM2.5 concentrations were measured using the DustTrak (Model 8520, TSI, St. Paul, MN, USA) at two schools within the city of London, Ontario (Canada). Site A was in a suburban environment while site B was in an urban setting. Monitoring took place for 3 weeks during winter (Feb. 16 - Mar. 8) and 3 weeks during spring (May 05 - 25) of 2010. The winter campaign monitored indoor PM2.5 only, while the spring campaign added outdoor monitors (PM2.5 and CO2) after the first week. Ten min. concentrations were used for analysis. Indoor measurements were split into weekday and weekend. For the same time interval, the outdoor concentrations showed mean values of 18 and 21 μg/m3 for sites A & B, respectively, both under the Canada Wide Standard of 30 μg/m3. Measurements at the two sites showed good associations (R^2 = 0.44), during the spring campaign. This indicates that the outdoor PM2.5 had similar sources. For indoor concentrations, Site B showed a significantly different mean concentration 5 times higher compared to site A during the winter ( 8.1 vs. 1.5 μg/m3 ) and 3 times higher (11.9 vs. 3.7 μg/m3) during the spring campaign. Since the outdoor concentrations were similar the large difference in indoor concentrations could be attributed to the following factors: site B being an older building, and the different physical characteristics between the two sites. The spring measurements showed an increase of 50% from weekday to weekend for site A and 22% for site B. The higher level of PM2.5 during weekends is possibly due to the infiltration of outdoor air while the ventilation/filtration system is shut off. During the winter campaign, Site A showed a 14% higher concentration during weekdays compared to weekends while site B weekend concentrations were 17% higher compared to weekday, which will be

  6. 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

  7. A radioimmunoassay for lignin in plant cell walls

    Energy Technology Data Exchange (ETDEWEB)

    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 {beta}-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 {eta}g/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. {sup 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{sub 2} delignification. The RIA was found to be less sensitive than expected, so several avenues for improving the method are discussed.

  8. 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

  9. The studies on aldosterone secretion rate by radioimmunoassay

    International Nuclear Information System (INIS)

    Takenouchi, Takahiko

    1974-01-01

    The aldosterone secretion rate was measured by radioimmunoassay in 12 normal subjects and 47 hypertensive patients. The values ranged from 25.0 to 60.2 ng/day with a mean of 39.6+-10.7 (S.D.) in 8 normal males and from 30.2 to 85.4 ng/day with a mean of 62.6+-26.8 (S.D.) in 4 normal females. The mean value in 21 cases with benign essential hypertension was found to be within normal range. No significant difference was found in the aldosterone secretion rate between the group of benign essential hypertension with suppressed renin activity and with nonsuppressed renin activity. Metabolic clearance rate in benign essential hypertension was observed to be within normal range. The aldosterone secretion rate in a few cases of benign essential hypertension failed to increase normally in response to sodium restriction (<50 mEq/day). The values in 11 cases of primary aldosteronism were found to be clearly higher, when compared with the values of normal subjects and subjects with benign essential hypertension. High values were found in patients suffering from malignant hypertension and in 3 with unilateral renal artery stenosis. The values in cases of bilateral renal artery stenosis, of pheochromocytoma, and of acromegaly with hypertension were within normal range. Low values in the aldosterone secretion rate were found in 3 cases each of 17α-hydroxylase deficiency and Cushing's syndrome. (JPN)

  10. Radioimmunoassay for progesterone in human saliva during the menstrual cycle

    Energy Technology Data Exchange (ETDEWEB)

    Luisi, M.; Franchi, F.; Kicovic, P.M.; Silvestri, D.; Cossu, G.; Catarsi, A.L.; Barletta, D.; Gasperi, M. (Pisa Univ. (Italy))

    1981-10-01

    A sensitive, specific and accurate radioimmunoassay of progesterone in human saliva is described, using /sup 3/H. The assay had a sensitivity of 8 pg/tube and blanks were negligible. The intra- and inter-assay coefficients of variation were 5.2 and 9.4%, respectively. The mean recovery from 60 samples was 93.2 +- 6.3%. Results obtained from nine healthy, normally menstruating women showed that salivary progesterone rose from the 4th day before ovulation to a mean peak (+- SD) of 1.14 +- 0.17 ng/ml on the 8th day after ovulation, followed by a gradual decline. Correlation of salivary and simultaneously obtained plasma progesterone levels was good (r = 0.47; P < 0.001), although the maximum percent increase in salivary progesterone was more than 10 times greater than that of plasma progesterone. Salivary progesterone is thought to reflect the unbound fraction of plasma progesterone and this non-invasive technique can be used for serial investigations in which frequent samplings are required.

  11. 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.

  12. Labelling and standardizing some pituitary hormones for radioimmunoassay

    International Nuclear Information System (INIS)

    Kim, Y.S.

    1976-11-01

    Optimum conditions for efficient 125 I labelling of human follicle stimulating hormone (FSH) and human chorionic gonadotropin (HCG) using chloramine-T have been established for radioimmunoassay (RIA). The amount of the hormone, chloramine-T, 125 I, and the reaction time were, respetively, controlled evaluating the yield and the bindability of the labelled hormone to its antibody. To measure the bindability, the labelled hormone was incubated together with its antibody for a definite temperature. In the separation of the free hormone (F) from the antibody bound (B), a double antibody technique was applied comparing with the chromatoelectrophoresis. For the efficient separation of the labelled hormone, two methods of separation such as gel filtration and gel electrophoresis were compared in the sensitivity and in the immunological activity points of view. Experiments for the production of HCG antibody were also conducted. The produced antisera were tested in two ways; i.e., the incubation test with the labelled hormone, and the Ouchterlony test. Using the produced anti-HCG serum and the purchased anti-FSH serum, standard dose-response curves were plotted correlating with the international standard preparation of the hormones

  13. Radioimmunoassay for plasma corticotropin in frogs (Rana esculenta L.)

    International Nuclear Information System (INIS)

    Vaudry, H.; Vague, P.; Dupont, W.; Leboulenger, F.; Vaillant, R.

    1975-01-01

    A radioimmunoassay technique has been developed for measuring frog plasma corticotropin (ACTH) without prior extraction. Using synthetic porcine ACTH as a reference standard, 131 I-labeled synthetic human ACTH (sp act greater than 500 mCi/mg) as tracer and rabbit anti-porcine ACTH serum, the lower measurable value was estimated at about 4 pg ACTH. Only human and porcine ACTH, ACTH, and frog pituitary ACTH reacted with the rabbit anti-porcine ACTH serum. No cross-reactivity has been found with synthetic ACTH, αMSH, and bovine βMSH. Appearance of damaged 131 I-h ACTH components after storage in plasma solutions was followed for 7 days. The conditions making it possible to reduce ACTH damage have been ascertained. The average plasma corticotropin level (+- CI) was found to be 38.8 +- 7.8 pg/ml without any significant difference between males and females. These results suggest that frog ACTH secretion has much in common with mammalian secretions

  14. Radioimmunoassay of angiotensin-II: methodology and standardization.

    Science.gov (United States)

    Lall, S B; Peshin, S S; Seth, S D

    1995-12-01

    The study was planned to set up and standardize the radioimmunoassay of Ang-II and to validate the procedure in terms of precision, sensitivity, specificity and recovery. The application of the developed assay was studied in normal healthy volunteers and in patients of renovascular hypertension (RVHT) and renal hypertension (RH). Synthetic human Ang-II was coupled to BSA by carbodimide condensation to get the hapten carrier conjugate which was injected in rabbits to raise the antibodies. The titre of 1:250 showed significant binding (56.79%) and was used for the assay. The sensitivity of the assay was 2 pg/ml and cross-reactivity with analogues of Ang-II was minimum. Mean Ang-II levels in normal subjects was 16 +/- 3.6 pg/ml. In patients of RVHT and RH, the peripheral blood Ang-II levels were found to be 876 +/- 8.6 and 108 +/- 2.3 pg/ml respectively. In patients of unilateral RVHT, renal vein Ang-II levels of the affected side were significantly higher than the unaffected side (P < 0.001). The results indicate that unextracted samples can be successfully utilized to estimate Ang-II levels.

  15. An Interlaboratory study of lipid effects on steroid radioimmunoassay

    International Nuclear Information System (INIS)

    Bolelli, G.F.; Franceschetti, F.; Mimmi, P.; Malvano, R.; Pilo, A.; Zucchelli; Rota, G.

    1986-01-01

    The lipid effects on the performances of routine steroid radioimmunoassay (RIA) have been assessed using the scheme of the CNR interlaboratory quality control program. Cortisol, estradiol, progesterone and testosterone assays have been considered. In the study, ca 80 laboratories were supplied with two sets of control plasma samples with different triglyceride contents (pool N, ca 120 mg/dl; pool L, ca 310 mg/dl), each corresponding to three steroid levels (level 0: charcoaldeprived samples; levels 1 and 2: the same added with increasing steroid amounts). A comparison of the neat results obtained by partecipants for both levels 1 and 2 of N and P panels - after subtraction of the concentrations estimated for level 0 - gave a direct information on lipid effects (triglycerides being assumed as an index of lipemia). In no case the abnormality high triglyceride content proved effective in practical terms, though significant differences were observed for testosterone and progesterone (ca 10% underestimation in pool L) and for estradiol (ca 10% overestimation in pool L)

  16. 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

  17. Measurement of guinea pig eosinophil major basic protein by radioimmunoassay

    International Nuclear Information System (INIS)

    Wassom, D.L.; Loegering, D.A.; Gleich, G.J.

    1979-01-01

    Guinea pig eosinophil major basic protein (MBP) was measured by radioimmunoassay (RIA) using 131 I-MBP. Two critical features of the assay were: (1) alkylation of the MBP with iodoacetamide prior to radioiodination and (2) inclusion of another basic protein, either protamine or histone, in the phosphate buffer. Freshly isolated non-alkylated MBP was immunologically deficient when compared to alkylated or reduced MBP, but its reactivity could be redtores by reduction with dithiothreitol and alkylation. Reduction and alkylation also restored the immunoreactivity of polymerized MBP. MBP levels were not elevated in sera from guinea pigs parasitized with Trichinella spiralis and having peripheral blood eosinophilia. Muscle extracts from Trichinella infected animals showed significantly higher levels of MBP activity than normal controls. MBP was measurable in extracts of untreated eosinophils, but reduction and alkylation of these extracts increased MBP activity several fold. The RIA permits detection of MBP in body fluids and tissues at levels as low as 2 ng./ml. The RIA is useful in assessing increased or decreased levels of MBP activity in samples from experimental animals when compared to samples from controls. (author)

  18. 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.

  19. 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

  20. 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

  1. Precision of radioimmunoassays by various types of data processing systems

    International Nuclear Information System (INIS)

    Ujiie, Morimichi

    1979-01-01

    The following are the result of the investigation of the precision of radioimmunoassays by various types of data processing systems presently performed in Japan. Chose 50 facilities, where 10 facilities of clinical laboratories were included. Tested 334, 485 cases per month, which corresponds to 40% of the total number of the cases treated all over the country. It was known that the data of 74% of all facilities and 94% of all tests were being processed by computing machines. In 66 times of data processing of insulin and T3 measurements, 32 were performed by the hyperbola method, 11 by the log-logit curve method of secondary degree, 9 by the logistic curve method and 8 by the log-logit curve method of first degree. Practically in more than 90% of all cases were processed by these 4 types of curve methods. In insulin measurements of many standard points (8 points), favourable results could be obtained by the logistic curve method. On the contrary, in T3 measurements of fewer standard points (5 points), the results from the method of log-logit curve of secondary degree were good. Favourable results of both insulin and T3 measurements could be obtained by the hyperbola method. While, in the insulin measurement by the method of log-logit curve of first degree, the values were a bit lower in the higher and lower concentration ranges, and 3 -- 4% higher than the actual values in the middle concentration range. (author)

  2. 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

  3. Specific radioimmunoassay of human. beta. -endorphin in unextracted plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, E. (Univ. of California, Berkeley); Saito, T.; Linfoot, J.A.; Li, C.H.

    1979-09-01

    With an antiserum against human ..beta..-endorphin (..beta..-EP) crossreacting <2% with human ..beta..-lipotropin (..beta..-LPH) by weight we have developed a radioimmunoassay that can detect 1 pg ..beta..-EP in diluted raw plasma. In a.m. fasting plasma of 14 normal subjects ..beta..-EP ranged from <5 to 45 pg/ml. ..beta..-EP was elevated in untreated, but normal in successfully treated Cushing's disease; undetectable in a patient with adrenal adenoma; extremely high in Nelson's syndrome; and elevated in a patient with bronchogenic carcinoma before, but undetectable after tumor resection. In subjects with intact hypothalamic-pituitary-adrenal axis, ..beta..-EP was undectectable after dexamethasone and increased after metyrapone administration and insulin-induced hypoglycemia. ..beta..-EP concentration was considerably lower in serum than in simultaneously collected plasma, but increased in serum left unfrozen for several hours after clot removal. Thus, ..beta..-EP behaves like a hormone responding to the same stimuli as ACTH and ..beta..-LPH and blood appears to contain enzymes both generating and destroying immunoreactive ..beta..-EP.

  4. 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

  5. Solid phase radioimmunoassays for human C-reactive protein

    International Nuclear Information System (INIS)

    Shine, B.; Beer, F.C. de; Pepys, M.B.

    1981-01-01

    Two new, rapid and sensitive radioimmunoassays for human C-reactive protein (CRP) have been established using antiserum coupled to magnetizable cellulose particles, which facilitate phase separation. A single antibody method, using solid phase anti-CRP, provides a sensitivity of 50 μg/l with a 1-h incubation time and intra- and inter-assay coefficients of variation of 10%. A double antibody method, using fluid phase rabbit anti-CRP serum and solid phase sheep anti-rabbit IgG serum, provides a sensitivity of 3 μg/l with an overnight incubation and intra- and inter-assay coefficients of variation of 10%. Among 468 sera from normal adult volunteer blood donors the median CRP concentration was 800 μg/l, interquartile range 340-1700 μg/l and range 70-29,000 μg/l. Ninety percent of samples contained less than 3 mg/l and 99% less than 10 mg/l. Low levels (14-650 μg/l) of CRP were detected both in amniotic fluids and in cerebrospinal fluids. (Auth.)

  6. Detection of myocardial infarct extension by CK-B radioimmunoassay

    International Nuclear Information System (INIS)

    Rothkopf, M.; Boerner, J.; Stone, M.J.; Smitherman, T.C.; Buja, L.M.; Parkey, R.W.; Willerson, J.T.

    1979-01-01

    Myocardial infarct extension after the acute event was defined as a second rise in the myocardial isoenzyme of serum creatine kinase (CK-B) after the initial return of CK-B to normal values. In 43 patients with acute myocardial infarct, CK-B was measured by radioimmunoassay every 12 hrs for 14 days. Nineteen patients had anterior transmural myocardial infarcts (AMI), 14 had inferior transmural myocardial infarcts (IMI), and 10 had subendocardial myocardial infarcts (SEMI). Infarct extension as detected by a second rise in serum CK-B occurred in six patients (32%) with AMI, two (14%) with IMI, and two (20%) with SEMI. Four patients with AMI also had clinically evident infarct extension. In the other six, the infarct extension was undetected clinically. The measurement of serum CK-B values with a quantitative and sensitive assay suggests that myocardial infarct extension occurs more commonly than clinically recognized, but the frequency of extension may be less than that reported in patients in whom precordial mapping and total serum CK values were measured to identify this phenomenon

  7. Laboratory training manual on radioimmunoassay in animal reproduction

    International Nuclear Information System (INIS)

    1984-01-01

    Reproduction must always be regarded as one of the major limiting factors in animal production and many of the modern methods for improving reproduction rely heavily on the ability to measure hormone levels in blood and milk. This has produced a world-wide demand for laboratory facilities to carry out hormone assays and the need for specialist training to allow these assays to be undertaken. The need to measure nanogram and picogram quantities and the use of radionuclides require a good deal of skill and care and this Manual has been prepared to aid training and provide the sort of information that rarely appears in scientific papers. It represents a further step in the Joint FAO/IAEA Division's series of Laboratory Training Manuals, and has been designed to aid training programmes of the type carried out during the Joint FAO/IAEA Interregional Training Course on Radioimmunoassay and its Application in Research on Animal Reproduction at Cornell University in July 1982. Many of the laboratory exercises described in this Manual are based on those conducted during the course

  8. An Evaluation by TSH Radioimmunoassay on Familial Thyroid Disorders

    International Nuclear Information System (INIS)

    Kim, Ji Yeul

    1989-01-01

    The occurrence of thyroid disorders is connected with iodine deficiency, defective synthesis or releasing of thyroid hormone and endemicity. Genetic factors are known as a single gene defects, interaction of multiple genes with environmental factors, as well as chromosomal aberrations. Diofnosis thyroid disorders is enforced by 13I uptake test, thyroid scanning with 131 I or 99m Tc and serum radioimmunoassays of T3, T4, free T4 and TSH. They were largely classified as hypothyroidism, hyperthyroidism, simple goiter and normal. The pedigree of 58 families was drawn by propositus, and then the correlation between thyroid disorders and TSH levels was analyzed. The results are as follows: 1) The offsprings and their mothers of 15 families were hypothyroidism, THS level was 5 folds for offsprings and 4 folds for mothers in comparison with control group. 2) 13 families were hyperthyroidism in siblings but their mothers were normal in thyroid function, TSH level of the siblings was lower than control group. 3) Though the offsprings and their mothers of 10 families were similar to TSH level of control group, they are all simple goiter, familial thyroid disorders, in other thyroid function test. The familial thyroid disorders suggested that these transmitted from mothers to offsprings with X-linked dominant or autosomal dominant inheritance.

  9. 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

  10. 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

  11. 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

  12. Tailoring Sandwich Face/Core Interfaces for Improved Damage Tolerance

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Berggreen, Christian; Carlsson, Leif A.

    2010-01-01

    A face/core debond in a sandwich structure may propagate in the interface or kink into either the face or core. It is found that certain modifications of the face/core interface region influence the kinking behavior, which is studied experimentally in the present paper. A sandwich double cantilever....... The transition points where the crack kinks are identified and the influence of four various interface design modifications on the propagation path and fracture resistance are investigated....

  13. The sandwich model: the 'music and dance' of therapeutic action.

    Science.gov (United States)

    Harrison, Alexandra M

    2014-04-01

    My premise is that a 'layered' approach is necessary to understand the process of exchanges that result in therapeutic change. I imagine these processes occurring in three layers - although the number of domains in which change is taking place is actually infinite - such as in a sandwich. The top layer, or top slice of bread of the sandwich, represents a broad view of the change process; it is non-linear and includes the feature of uncertainty, a general principle of dynamic systems theory. The middle layer, or the meat of the sandwich, is explained by theories that are immediately and clinically useful to a therapist, such as psychoanalytic theories. These are primarily linear theories and use language and symbols to 'tell a story of what happened'. The bottom layer, or bottom slice of bread of the sandwich, is the micro-process; this layer includes the moment-to-moment patterns of coordinated rhythms that both communicate meaning and provide the essential scaffold for all higher-level change processes. The micro-process also requires a non-linear theory to make sense of its variability and emergent properties. Taking a bite out of the sandwich will include a 'polysemic bundle of communicative behaviors' (Harrison and Tronick, 2011). I will illustrate the 'sandwich model' with the clinical case of the analytic treatment of a 5 year-old boy. Copyright © 2013 Institute of Psychoanalysis.

  14. A novel robotic arm driven by sandwich piezoelectric transducers.

    Science.gov (United States)

    Jiang, Zheng; Wang, Liang; Jin, Jiamei

    2018-03-01

    In this work, a novel robotic arm driven by sandwich piezoelectric transducers is proposed. The proposed robotic arm is composed of three arms and four joints. Each arm consists of a sandwich piezoelectric transducer and an H-shaped hollow frame. The sandwich piezoelectric transducer utilizes frictional force to drive the joints on its both sides to rotate simultaneously. The joint between two arms can be driven to rotate in two perpendicular directions by two sandwich piezoelectric transducers. The rotation of joints results in the arm motion. Utilizing the finite element method, the optimized geometrical parameters of the sandwiched piezoelectric transducer are obtained, and the operating principle is demonstrated. A prototype of the robotic arm is also fabricated and assembled, it is 573 g in weight and 412 mm in length, and the maximum rotation angle of each joint is 160°. The mechanical characteristics of the robotic arm prototype are investigated by experiments. The results indicate that, when the excitation frequency of one sandwich piezoelectric transducer is 37.4 kHz, the arms on its two sides rotate in opposite directions with an average rotational velocity of 320 deg/s at 330 V pp , a resolution of 100 μrad at 230 V pp , and a startup and shutdown response time of 40 ms and 30 ms at 230 V pp , respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Modified Mode-I Cracked Sandwich Beam (CSB) Fracture Test

    Science.gov (United States)

    Smith, S. A.; Shivakumar, K. N.

    2001-01-01

    Five composite sandwich panels were fabricated using vacuum assisted resin transfer molding (VARTM). Four of these panels had E-glass/vinylester facesheets and one had carbon/epoxy facesheets. The sandwich panels had different density PVC foam cores. The four E-glass panels had core densities of 80, 100, 130, 200 kg/cu m. The sandwich with carbon/epoxy 3 facesheets had a core with density of 100 kg/cu m. Fracture tests were conducted using a modified Cracked Sandwich Beam (CSB) test configuration. Load displacement curves were obtained for loading and unloading of the specimens during crack growth. Various increments of crack growth were monitored. Critical Strain Energy Release Rates (SERR) were determined from the tests using the area method. The critical values of SERR can be considered the fracture toughness of the sandwich material. The fracture toughness ranged 367 J/sq m to 1350 J/sq m over the range of core densities. These results are compared to the Mode-I fracture toughness of the PVC foam core materials and values obtained for foam-cored sandwiches using the TSD specimen. Finite-element analyses (FEA) were performed for the test configuration and Strain Energy Release Rates were calculated using the Virtual Crack Closure Technique (VCCT). The SERR values determined from the FEA were scaled to the fracture loads, or critical loads, obtained from the modified CSB tests. These critical loads were in close agreement with the test values.

  16. Structure of an epiphytic hydroid community on Cystoseira at two sites of different wave exposure

    Directory of Open Access Journals (Sweden)

    Anuschka Faucci

    2000-12-01

    Full Text Available Epiphytism is a strategy by which opportunistic species such as hydroids, escape the intense levels of competition in marine hard bottom communities. Species of the macroalgae Cystoseira have a seasonal turnover of the frond, and we hypothesise that epiphytic hydroids colonising such an unstable substrate might show some degree of specialisation. Here the first systematic study on hydroid-Cystoseira communities is presented. In particular, the seasonal and spatial distribution of epiphytic hydroids on three species of Cystoseira at two sites of different wave exposure at Porto Cesareo (Ionian Sea/Italy were investigated. Thirty-two hydroid species were recorded which are well known from other substrates and thus are not specific to Cystoseira; dominant species were all thecates. The influence of biological factors such as competition and the structure and abundance of the host, seem to have little influence on the hydroid community. The factors of greatest influence were mostly abiotic: sedimentation rate, nutrient levels, temperature and most especially water movement. The importance of water movement was evident in the higher colonisation of algal stems, higher hydroid frequency, larger colonies, reduced colony height, species composition, and distribution on the stems at the wave-exposed site.

  17. Salt-mediated two-site ligand binding by the cocaine-binding aptamer.

    Science.gov (United States)

    Neves, Miguel A D; Slavkovic, Sladjana; Churcher, Zachary R; Johnson, Philip E

    2017-02-17

    Multisite ligand binding by proteins is commonly utilized in the regulation of biological systems and exploited in a range of biochemical technologies. Aptamers, although widely utilized in many rationally designed biochemical systems, are rarely capable of multisite ligand binding. The cocaine-binding aptamer is often used for studying and developing sensor and aptamer-based technologies. Here, we use isothermal titration calorimetry (ITC) and NMR spectroscopy to demonstrate that the cocaine-binding aptamer switches from one-site to two-site ligand binding, dependent on NaCl concentration. The high-affinity site functions at all buffer conditions studied, the low-affinity site only at low NaCl concentrations. ITC experiments show the two ligand-binding sites operate independently of one another with different affinities and enthalpies. NMR spectroscopy shows the second binding site is located in stem 2 near the three-way junction. This ability to control ligand binding at the second site by adjusting the concentration of NaCl is rare among aptamers and may prove a useful in biotechnology applications. This work also demonstrates that in vitro selected biomolecules can have functions as complex as those found in nature. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  18. Soil micromorphology, geochemistry and microbiology at two sites on James Ross Island, Maritime Antarctica

    Science.gov (United States)

    Meier, Lars A.; Krauze, Patryk; Prater, Isabel; Scholten, Thomas; Wagner, Dirk; Kühn, Peter; Mueller, Carsten W.

    2017-04-01

    Referring to the fundamental question in ecosystem research, how biotic and abiotic processes interact, only a few studies exist for polar regions that integrate microbiological and soil scientific studies . Soils comprise the complex structure and environment that fosters water storage and nutrient cycling determined by its unique chemical, physical and biological properties with respect to the specific climate and parent material. In the extreme environment of Antarctica, soil biological processes are primarily controlled by microbial communities (Bacteria, Archaea and Fungi), and thus microbiota may also determine soils chemical and physical properties in a landscape lacking higher plants at an average air temperature below 0°C. James Ross Island, Maritime Antarctica, offers a pristine laboratory and an exceptional opportunity to study pedogenesis without the influence of vascular plants and burrowing animals. We analysed micromorphological features, chemical and microbiological measures at two sites on James Ross Island (Brandy Bay and St. Martha Cove) with similar substrates (mostly fine-grained calcareous sandstones and siltstones of the Alpha Member of the Santa Martha Formation with varying amounts of conglomerates and mudstones) at similar topographic positions (small plateaus at similar elevation (80m a.s.l.)). The sites represent luv- and leeward conditions with respect to the main southwesterly winds. The climate on James Ross Island is to be described as semi-arid polar-continental, which is in clear contrast to the Southern Shetlands (e.g. King George Island) north of the Antarctic Peninsula. We will present first results of soil physical (bulk density, soil moisture and grains size distribution), pedochemical (SOC, total N and S, pH, CECeff, and pedogenic oxides) micromorphological and microbial analyses (Microbial DNA content, microbial abundances).

  19. Monitoring the reproductive performance in awassi ewes using progesterone radioimmunoassay

    International Nuclear Information System (INIS)

    Zarkawi, M.

    1999-01-01

    Jugular serum progesterone (P-4) concentrations were assessed using radioimmunoassay (RIA) kits for about 1 year in 16 local Awassi ewes aged about 1 year and weighing on average 37.4 ±4.9 (range 29.5-44.0 kg). Average pre-mating live weight of animals was different (P 0.05) between animals in average basal pre-mating P-4 concentration, maximum P-4 concentration during the luteal phase in non-pregnant ewes and in the length of the gestation period average basal pre-mating P-4 concentration was 0.62±0.44 (range 0-1.7 nmol l -1 ). Average maximum P-4 concentration during the luteal phase in non-pregnant ewes was 11.0±3.3 (range 5.8-18 nmol l -1 ). Length of gestation period varied from 149 to 155 days with an average of 152±2.3 days. Maximum P-4 concentration during gestation was different (P -1 ). The accuracy of pregnancy diagnosis at around 21 days pot-mating using RIA was 100%. It was concluded that Awassi sheep in Syria have a long breeding season that could start as early as April and last through September. Therefore, ewes might be included in oestrous synchronisation programmes to give three lambs in 2 years. It was also concluded that P-4 concentration under 3.18 nmol l -1 is indicative of either anoestrous or follicular and early luteal phase of the oestrous cycle in Awassi ewes kept in Syria and that RIA could be used for P-4 determination and successful early diagnosis of pregnancy in Awassi sheep. (author)

  20. Quality control of radioimmunoassay reagents for T4

    International Nuclear Information System (INIS)

    Wayan Radiatning, S.

    1987-01-01

    Quality control of radioimmunoassay reagents for T4. A program of quality control testing has been carried out for 125 I-T4, T4 standards and T4 antisera. 125 I-labelled T4 has been tested for its specific activity, radiochemical purity using a Sephadex G-25 column, immunological activity, based on the immunological reaction between labelled antigen and excess T4 antibody, and non-specific binding. The useful shelf-life of the labelled compound was determined by monitoring the decrease in radiochemical purity and immunological activity, and the increase in non-specific binding. T4 standards were calibrated by means of T4 RIA kit manufactured by DPC (Diagnostic Products Corporation). A test on parallelism was also performed using hyperthyroid sera. T4 antisera were evaluated with respect to titre, avidity and specifity. The test results on 125 I-T4 show a specific activity varying between 1830-2020 uCi/ug, a radiochemical purity above 90%, an immunological more than 80% and a non-specific binding of less than 5%. The standard curve for T4 was found to coincide well with the standard curve of the DPC kit and parallel with the curve for hyperthyroid sera. The titre of T4 antisera obtained was 1:300, the avidity was about 4.8 x 10 7 and the cross-reaction for T3 was 1.6%. It can be concluded from the experimental results, that the 125 I-T4, T4 standards and T4 antisera prepared meet the requirements for the manufacture of T4 kits. (author). 5 refs.; 14 figs

  1. Quantification of the adrenal cortex hormones with radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Badillo A, V.; Carrera D, A. A.; Ibarra M, C. M., E-mail: vbadillocren@hotmail.co [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-10-15

    The pathologies of the adrenal cortex -adrenal insufficiency and Cushing syndrome- have their origin on the deficit or hypersecretion of some of the hormones that are secreted by the adrenal cortex, which is divided in three zones anatomically defined: the external zone, also called the zona glomerulosa, which is the main production site of aldosterone and mineralocorticoids; the internal zone, or zona reticularis, that produces androgens; and the external zone, or zone 1 orticotrop, which is responsible for producing glucocorticoids. In this work, a quantitative analysis of those hormones and their pathologic trigger was made; the quantification was made in the laboratory by means of highly sensitive and specific techniques, in this case, the radioimmunoassay, in which a radioisotope I-125 is used. This technique is based on the biochemical bond-type reaction, because it requires of a substance called the linker, which bonds to another called ligand. This reaction is also known as antigen-antibody (Ag-Ab), where the results of the reaction will depend on the quantity of antigen in the sample and on its affinity for the antibody. In this work, a 56 patients (of which 13 were men and 43 women) study was made. The cortisol, the ACTH, the androsterone and the DHEA values were very elevated in the majority of the cases corresponding to women, predominating cortisol; while in men, a notorious elevation of the 17 {alpha}-OH-PRG and of the DHEA-SO{sub 4} was observed. Based on that, we can conclude that 51 of them did not have mayor complications, because they just went to the laboratory once, while the remaining 5 had a medical monitoring, and they visited the laboratory more than one occasion, tell about a difficulty on their improvement. According to the results, an approximate relation of 8:2 women:men, respectively, becomes clear to the hormonal pathologies of the adrenal cortex. (Author)

  2. The reproductive performance in female Damascus goats using progesterone radioimmunoassay

    International Nuclear Information System (INIS)

    Zarkawi, M.; Al-Masri, M. R.

    1998-12-01

    An experiment was conducted on Damascus goats' female kids and does to study the reproductive performance by identifying some reproductive parameters such as age and weight at puberty, start of the breeding season, duration of pregnancy and other related parameters. The above objectives were met by means of the measurement of progesterone levels in blood sera using radioimmunoassay. The results could be summarized as follows: 1- Average weight of female kids at age of 7-8 months was 30.2 kg, at puberty was 35.6 ky and at mating was 41.6 kg. 2- There were individual differences in the age at puberty ranging from 266 to 653 days. 3- At age of 7-8 months, progesterone level was 0 n mol/1 in 8, and 0.1 and 0.2 n mol/1 in the 2 remaining female kids. This level increased to an average of 6.81 n mol/1 at puberty. 4- Average duration of pregnancy was 149.0 days, overall kids' birth weight was 3.73 kg, for singles was 4.43 kg, whereas for twins was 3.21 kg, for the kids produced by the female kids. Average kids' birth weight produced by the does was: overall 4.63 kg, singles 4.02 kg and for twins was. 4.18 kg. 5- Average progesterone e level on day 21 post-mating was 23.02 n mol/1. Therefore, the accuracy of early pregnancy diagnosis was 100%. 6- The breeding season for the experimental does started in September. (author)

  3. Development of a Radioimmunoassay for Bovine Chymosin B

    Directory of Open Access Journals (Sweden)

    Borceux, JP.

    2007-01-01

    Full Text Available The present study was conducted to develop and validate a specific radioimmunoassay system for measurement of bovine chymosin B (bChyB concentrations in plasma samples. Bovine ChyB was used for immunization of rabbits and as standard and tracer. Chymosin B concentrations were measured in plasma samples from two groups of calves (Group 1: calves sampled from birth to 24 hours; Group 2: calves sampled from Day 1 to 21 after birth and from one cow during the peri-partum period. Detection limit of the assay was 9.0 ng/ml. Recovery was higher than 89.3%. Repeatability and reproducibility ranged from 1.52% to 5.23% and from 1.52% to 12.57% respectively. No cross-reaction was found with pepsinogen A from bovine, porcine or human origins. In Group 1, bChyB concentrations increased from 47.3 ± 45.1 ng/ml (5 min after birth to 325.5 ± 161.2 ng/ml (12 hours after birth, then no significant change was observed till 24 hours after birth (293.0 ± 161.5 ng/ml. In Group 2, concentrations decreased from Day 1 (455.3 ± 191.1 ng/ml to Day 21 (117.9 ± 85.1 ng/ml. In adult cow, mean concentration was 136.0 ± 32.3 ng/ml. In conclusion, bChyB is able to cross the stomach basal membrane and to reach the blood circulation at detectable levels in both young calves and adult cows.

  4. Development of reagents for radioimmunoassay of: triiodothyronine, thyroxine and thyrotrophin

    International Nuclear Information System (INIS)

    Delgado S, B.; Lavalley E, C.; Ruiz J, A.; Garcia F, C.; Zamorano A, F.

    1991-12-01

    The radioimmunoassay (RIA) of thyroid hormones it is the but it frequents of all the studies carried out by RIA in the laboratories of Nuclear Medicine, these essays are carried out with imported reagents. In the ININ the reagents and the necessary methodology have been developed for the triiodothyronine (T3), thyroxine (T4) and thyrotrophin (TSH). The good titles of the antibodies (Ac) primary for each hormone were of 1:4,000; 1:750 and 1:1,500. The used separation system was of double Ac with PEG to 10%, with titles of 1:10 for the second Ac of lamb. The specific activity for 125-I-T3 and 125-I-T4 oscillate between 850 at 900 μCi / μ g: being this of 90 μ Ci /μg for TSH. To the first two hormones they were added 1-8 aniline naftalen sulfonic acid (ANS) to concentrations of 3 and 2 mg/ml respectively. As buffer for T3 and T4 it was used Tris-HCl pH 8.6 and PBS with normal serum of rabbit (SNC) for TSH. The standards got ready in buffer or free serum of thyroid hormones. The slope of the standard curves varied between -2.3 to -2.7 and the variation intra and inter assay among 4 to 10%. It is had at the moment in the ININ with standardized reagents for the RIA of T3, T4 and TSH, it is hoped to carry out tests in other laboratories and to establish the conditions of stability more appropriate to begin the preparation of pilot reagents. (Author)

  5. Formation and electronic structures of organoeuropium sandwich nanowires.

    Science.gov (United States)

    Hosoya, Natsuki; Takegami, Ryuta; Suzumura, Jun-ichi; Yada, Keizo; Miyajima, Ken; Mitsui, Masaaki; Knickelbein, Mark B; Yabushita, Satoshi; Nakajima, Atsushi

    2014-09-18

    Organoeuropium sandwich clusters, comprising europium (Eu) and 1,3,5,7-cyclooctatetraene (COT) (Eu(n)(COT)(m)), were produced in the gas phase using a laser vaporization synthesis method. Photoionization mass spectra revealed an exclusive Eu(n)(COT)(m) formation with three compositions: m = n + 1, m = n, and m = n - 1, which, we propose, correspond to full-sandwich, half-sandwich, and inverted-sandwich structures, respectively. The charge distributions, metal-ligand bonding characteristics, and electronic structures of the clusters were comprehensively investigated by photoionization measurements of Eu(n)(COT)(m) neutrals and by photoelectron spectroscopy of Eu(n)(COT)(m)(-) and isoelectronic Ba(n)(COT)(m)(-) anions. The results confirmed that (1) highly ionic metal-ligand bonding is formed between Eu(2+) and COT(2-) within the sandwich structure (at the termini, ionic forms are Eu(+) and COT(-)) and (2) size dependence of orbital energy can be explained by the Coulombic interaction of simple point charge models between the detaching electrons and dipoles/quadrupoles. When the terminus of the sandwich clusters is Eu(2+), COT(2-), or Eu(0), the orbital energy of the electron detachment channel at the opposite terminus strongly depends on the cluster size. In this case, the molecular stack behaves as a one-dimensionally aligned dipole; otherwise, it behaves as a quadrupole, and the relationship between cluster size and electron detachment energy is much weaker. The study also reports on the 4f orbital energy in Eu ions and the formation mechanism of organoeuropium sandwich nanowires up to 12 nm in length. The nanowires are formed by successive charge transfer at the terminal part, Eu(+) and COT(-), which reduces the ionization energy and increases the electron affinity, respectively.

  6. The Sandwich Priming Paradigm Does Not Reduce Lexical Competitor Effects.

    Science.gov (United States)

    Trifonova, Iliyana V; Adelman, James S

    2018-02-01

    We investigated the mechanisms underlying sandwich priming, a procedure in which a brief preprime target presentation precedes the conventional mask-prime-target sequence, used to study orthographic similarity. Lupker and Davis (2009) showed the sandwich paradigm enhances orthographic priming effects: With primes moderately related to targets, sandwich priming produced significant facilitation, but conventional priming did not. They argued that unlike conventional priming, sandwich priming is not susceptible to an uncontrolled counteractive inhibitory process, lexical competition, that cancels out moderate facilitation effects. They suggest lexical competition is eliminated by preactivating the target's representation, privileging the target over similar lexical units (competitors). As such, it better measures orthographic relatedness between primes and targets, a key purpose of many priming studies. We tested whether elimination of lexical competition could indeed account for the observed orthographic priming boost with sandwich priming. In three lexical decision experiments and accompanying simulations with a competitive network model, we compared priming effects in three preprime procedures: no preprime (conventional), identity (target) preprime (sandwich), and competitor preprime (included to exacerbate lexical competition). The related prime conditions consisted of replaced-letters, shared neighbor (one-letter-different from both competitor preprime and target), and transposed-all-letter nonword primes. Contrary to the model's predictions, the competitor preprime did not attenuate (Experiment 1) or even reverse the priming effect (Experiment 2). Moreover, the competitor enabled facilitatory priming that was absent with no preprime (Experiment 3). These data suggested that the sandwich orthographic boost could not be attributed to reduced lexical competition but rather to prelexical processes in word recognition. (PsycINFO Database Record (c) 2018 APA, all

  7. A method of quality control in continuous for the thyroid hormones radioimmunoassay

    International Nuclear Information System (INIS)

    Savoie, J.C.; Kawadry, G.; Leger, F.A.; Hantour, Z.; Baulieu, J.L.

    1980-01-01

    The exploration of the thyroid function requires nowadays the T4, T3 and TSH radioimmunoassays. These assays, performed several times each week, raise the problem as to how control the quality of every new series and of every result. The authors describe the principle features of a program devised to automatically control 'in continuous' the quality of the radioimmunoassays. This program was developed on a SIMIS 3-INFORMATEK system. It is derived from Rodbard's work, uses Logit-Log transformation and ensures the consistent interseries control of many characteristic parameters. No series nor individual results are exploited i.e. edited without prior control of quality a decision from which is made to validate or reject. This program is but one solution -among many others possible- corresponding to a necessity: the need presently felt and perhaps to-morrow requested for some permanent quality control of the results of radioimmunoassays [fr

  8. Quantitative determination of albumin in urine (microalbuminuria) by electroimmunoassay and radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Zanazzi, M.; Sverzellati, E.; Scarpioni, L.; Pantano, E.; Cerri, L.; Cecchettin, M.

    1986-10-01

    Electroimmunoassay and radioimmunoassay are two methods specifically designed for rapid and accurate analysis of subclinical amounts of proteins in urine. These assays are very sensitive to detect low concentrations of albumin in urines (17-75 mg/24 hrs) and to discover patients with microalbuminuria. Electroimmunoassay and radioimmunoassay are similar for precision and accuracy. Electroimmunoassay results can be obtained within few hours (3 hrs) and a remarkable advantage is the low cost of the equipment and the reagents. Radioimmunoassay results can be obtained within 2 hours. This assay is useful to perform multiple assays in big laboratories, but electroimmunoassay is much more convenient for little assays, when there are few urine samples to investigate.

  9. Process for preparation of a solid-phase radioimmunoassay support and use thereof

    International Nuclear Information System (INIS)

    Meriadec, B.; Roubertie, P.

    1979-01-01

    A process is described for the preparation of a support useful in radioimmunoassay chromatographic columns. The process involves the preparation of a chromatographic gel capable of selectively retaining one or more components contained in an antigen-antibody-containing solution. The gel is bound to the appropriate antiserum, then freeze-dried, pulverized and compressed into a tablet. The tablet support swells upon contact with an antigen-antibody-containing solution to conform to the shape of the columns. An example of the application of this support in the radioimmunoassay of thyroid-stimulating hormone is described. This type of support is also particularly useful in second antibody solid phase radioimmunoassays since there is no limit to the size of the antigen to which this technology may be applied. (U.K.)

  10. Biogenic and fossil contributions to organic aerosol at two sites on the North Slope of Alaska

    Science.gov (United States)

    Moffett, Claire; Barrett, Tate; Gunsch, Matthew; Pratt, Kerri; Sheesley, Rebecca

    2017-04-01

    Aerosols both directly and indirectly affect the Earth's albedo by scattering or absorbing solar radiation and acting as cloud and ice condensation nuclei. In order to better understand the variability of aerosol sources in the Alaskan Arctic, this study utilizes radiocarbon analysis for the apportionment of total organic carbon to fossil and contemporary carbon sources. Fossil sources include fossil fuel combustion and secondary organic aerosol (SOA) from fossil precursors while contemporary sources include biomass combustion, primary biogenic emissions, and SOA produced from biogenic and biomass combustion-derived precursors. Total suspended particulate (TSP) samples were collected in August/September 2012, 2015, and 2016 at two Department of Energy Atmospheric Radiation Measurement climate research facilities. Barrow, AK, is located on the northern most point of the United States; the site is 7.4 km north of the village of Barrow (population 4,581). Research shows the site receives minimal aerosol contribution from the village with dominant contributions from long range transport. Oliktok Point, AK, is 300 km south east of Barrow in a region of intense petroleum development. It receives contributions from the petroleum industry surrounding it as well as from long range transport. The proximity of the two sites allows for a finer spatial analysis of Arctic carbonaceous aerosol source contributions. Samples were analyzed for organic carbon (OC), elemental carbon (EC), and radiocarbon (14C) abundance. Preliminary results for 2015 show Barrow had OC concentrations from 0.05 to 0.16 μg/m3, while Oliktok had concentrations of OC from 0.11 to 0.27 μg/m3. EC concentrations ranged from 0.002 to 0.013 μg/m3 in Barrow, 0.002 to 0.088 μg/m3 in Oliktok. In Barrow, 14C abundance shows the contribution of fossil sources remained in the range of 21% to 28%. At Oliktok, analysis reveals an increase from 30% contribution from fossil sources in August to a 70% contribution at

  11. Sandwich mapping of schistosomiasis risk in Anhui Province, China.

    Science.gov (United States)

    Hu, Yi; Bergquist, Robert; Lynn, Henry; Gao, Fenghua; Wang, Qizhi; Zhang, Shiqing; Li, Rui; Sun, Liqian; Xia, Congcong; Xiong, Chenglong; Zhang, Zhijie; Jiang, Qingwu

    2015-06-03

    Schistosomiasis mapping using data obtained from parasitological surveys is frequently used in planning and evaluation of disease control strategies. The available geostatistical approaches are, however, subject to the assumption of stationarity, a stochastic process whose joint probability distribution does not change when shifted in time. As this is impractical for large areas, we introduce here the sandwich method, the basic idea of which is to divide the study area (with its attributes) into homogeneous subareas and estimate the values for the reporting units using spatial stratified sampling. The sandwich method was applied to map the county-level prevalence of schistosomiasis japonica in Anhui Province, China based on parasitological data collected from sample villages and land use data. We first mapped the county-level prevalence using the sandwich method, then compared our findings with block Kriging. The sandwich estimates ranged from 0.17 to 0.21% with a lower level of uncertainty, while the Kriging estimates varied from 0 to 0.97% with a higher level of uncertainty, indicating that the former is more smoothed and stable compared to latter. Aside from various forms of reporting units, the sandwich method has the particular merit of simple model assumption coupled with full utilization of sample data. It performs well when a disease presents stratified heterogeneity over space.

  12. Experimental study on mechanical properties of aircraft honeycomb sandwich structures

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.

    2010-06-01

    Full Text Available Mechanical behaviour of sandwich panels under different conditions have been exprimentally studied in this research to increase the knowledge of aircraft sandwich panel structures and facilitate design criteria for aircraft structures. Tests were concentrated on the honeycomb sandwich structures under different loads including flexural, insert shear, flat wise tension and compression loads. Furthermore, effect of core density and face material on mechanical behavior of different samples were investigated and compared with analytical and FEM method. Effects of skin thickness on strength of honycomb sandwhich panels under shear pull out and moments have also been considerd in this study. According to this investigation, insert strength and flexural test under different load conditions is strongly affected by face thickness, but compression and tearoff (falt wise tensile properties of a sandwich panel depends on core material. The study concludes that the correlation between experimental results and the analytical predictions will enable the designer to predict the mechanical behaviour and strength of a sandwich beam; however, applied formula may lead engineers to unreliable results for shear modulus.

  13. Development of a heterologous radioimmunoassay for the measurement of human prolactin in serum

    International Nuclear Information System (INIS)

    Vieira, J.G.H.; Russo, E.M.K.; Lengyel, A.M.J.; Maciel, R.M.B.

    1981-01-01

    The development of a heterologous radioimmunoassay method is described for the measurement of human prolactin in serum. Antisera were produced in rabbits using ovine prolactin as the immunogen; the best antiserum produced enebled the development of a simple and rapid method, with sufficient sensitivity (2ng/ml). The cross reactivity with human growth hormone and with placental lactogen was inferior to 0.03%. The labelling of human prolactin was done using the Lactoperoxidase method, followed by a column chromatography purification in a Sephadex G-100. Using 153 sera, the described method was compared with a homologous radioimmunoassay for human prolactin, and no significant difference was shown. (Author) [pt

  14. Development and characterization of a homologous radioimmunoassay for deer mouse (Peromyscus maniculatus bairdii) prolactin

    International Nuclear Information System (INIS)

    Marr, G.A.; Colosi, P.; Desjardins, C.; Talamantes, F.

    1983-01-01

    A highly specific and sensitive homologous radioimmunoassay has been developed for the secreted form of prolactin from the deer mouse Peromyscus maniculatus bairdii. Peromyscus serum and pituitary homogenates displayed paralled dilution response curves, and no cross reaction was seen with either mouse prolactin, mouse growth hormone or rat prolactin. The assay was sensitive to 25 picograms per tube and the intra- and inter-assay coefficients of variation were 5 and 3.6%, respectively. In addition, the authors have demonstrated that Peromyscus prolactin does not show parallel displacement in a homologous radioimmunoassay utilized for measuring prolactin in the common laboratory mouse

  15. Heterophilic antibodies interfering with radioimmunoassay. A false-positive pregnancy test

    Energy Technology Data Exchange (ETDEWEB)

    Vladutiu, A.O.; Sulewski, J.M.; Pudlak, K.A.; Stull, C.G.

    1982-11-19

    A young woman with amenorrhea had a consistently positive pregnancy test result (serum radioimmunoassay measurement of ..beta..-human chorionic gonadotropin hormone). No fetal or placental tissue was found after uterine curettage and exploratory laparotomy. The false-positive pregnancy test result was due to heterophilic antibovine and antigoat antibodies in the patient's serum. These antibodies interfered with radioimmunoassays using goat antibodies. This case shows that serum heterophilic antibodies can interfere with immunoassays and result in unnecessary diagnostic procedures and/or unnecessary treatment.

  16. Heterophilic antibodies interfering with radioimmunoassay. A false-positive pregnancy test

    International Nuclear Information System (INIS)

    Vladutiu, A.O.; Sulewski, J.M.; Pudlak, K.A.; Stull, C.G.

    1982-01-01

    A young woman with amenorrhea had a consistently positive pregnancy test result (serum radioimmunoassay measurement of #betta#-human chorionic gonadotropin hormone). No fetal or placental tissue was found after uterine curettage and exploratory laparotomy. The false-positive pregnancy test result was due to heterophilic antibovine and antigoat antibodies in the patient's serum. These antibodies interfered with radioimmunoassays using goat antibodies. This case shows that serum heterophilic antibodies can interfere with immunoassays and result in unnecessary diagnostic procedures and/or unnecessary treatment

  17. What type of statistical model to choose for the analysis of radioimmunoassays

    International Nuclear Information System (INIS)

    Huet, S.

    1984-01-01

    The current techniques used for statistical analysis of radioimmunoassays are not very satisfactory for either the statistician or the biologist. They are based on an attempt to make the response curve linear to avoid complicated computations. The present article shows that this practice has considerable effects (often neglected) on the statistical assumptions which must be formulated. A more strict analysis is proposed by applying the four-parameter logistic model. The advantages of this method are: the statistical assumptions formulated are based on observed data, and the model can be applied to almost all radioimmunoassays [fr

  18. The use of the radioimmunoassay for detection of diethylstilbestrol in fecal samples of fattened calves

    International Nuclear Information System (INIS)

    Agthe, O.

    1980-01-01

    A radioimmunoassay for diethylstilbestrol (DES) in fecal samples of fattened calves is described. The antibody used in this test showed no cross reactions with natural estrogens or other steroids. Blank values (fecal samples without DES) varied between 0 an 4,9 ng DES-equivalent/g sample. The distribution of blank values shows the significant proof of existence of DES in concentrations above 10 ng/g sample. The method has been applied for the control of living calves at the producer. Examples of illegal DES applications are given. The described radioimmunoassay is suitable for routine analysis as a control for illegal estrogen treatment. (orig.) [de

  19. Labelling of human follicle stimulant hormone with 125I, for radioimmunoassay

    International Nuclear Information System (INIS)

    Pinto, H.; Werner, R.S.; Lerario, A.C.; Toledo e Souza, I.T. de; Wajchenberg, B.L.; Pieroni, R.R.

    1976-01-01

    An efficient labeling of human Follicle Stimulant Harmone is essential to development of sensitive radioimmunoassays. Iodination by Chloramine T method frequently is subject to severe iodination damage and some preparations are unaccetable for radioimmunoassays. Modifications to the Hunter method, changing incubation time, reaction temperature and reducing Chloramine T amount used in the reaction, were performed in obtaining a more effective labeling. FSH-125 I fraction obtained from Sephadex G-75 column purification presented excellent immunoreactivity and quality control of the steps of the reaction demonstrated a high percentage (90%) of intact Follicle Stimulant Hormone [pt

  20. 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)

  1. CA 125 radioimmunoassay for the diagnosis and assessment of the effectiveness of therapy of ovarian cancer

    International Nuclear Information System (INIS)

    Sagan, D.L.; Chebotareva, Eh.D.; Evtushenko, G.V.

    1989-01-01

    The paper is concerned with the results of CA-125 radioimmunoassay in 163 patients (584 tests) with benign and malignant ovarian diseases and other small pelvic diseases which were diagnosed before operation as ovarian tumors. CA-125 radioimmunoassay can be used in combination with other methods for investigation of patients with suspected ovarian cancer and for differential diagnosis of malignant ovarian tumors to distinguish them from other malignant tumors of the small pelvis. The investigation of CA-125 indices in the course of disease was indicative of the effectiveness of antitumor therapy

  2. Examination of Sandwich Materials Using Air-Coupled Ultrasonics

    DEFF Research Database (Denmark)

    Borum, K.K.; Berggreen, Carl Christian

    2004-01-01

    The air-coupled ultrasonic techniques have been improved drastically in recent years. Better equipment has made this technique much more useful. This paper focuses on the examination of sandwich materials used in naval ships. It is more convenient to be able to make the measurements directly...... in atmospheric air instead of using immersion technique. The air-coupled techniques have been used in through-transmission mode using separate sender and receiver transducer. The frequency was either 50 kHz or 120 kHz. Laboratory tests on glass fibre/PVC foam core sandwich panels showed that debonds between core...... and skin laminate could be found by the air-coupled technique. It was therefore decided to use this technique in-situ during mechanical testing of sandwich panels. These tests were done in order to verify a developed FEM code using interfacial fracture mechanics and illustrated on a superstructure...

  3. Graphene-Based Sandwich Structures for Frequency Selectable Electromagnetic Shielding.

    Science.gov (United States)

    Song, Wei-Li; Gong, Congcheng; Li, Huimin; Cheng, Xiao-Dong; Chen, Mingji; Yuan, Xujin; Chen, Haosen; Yang, Yazheng; Fang, Daining

    2017-10-18

    Due to substantial development of electronics and telecommunication techniques, materials with electromagnetic interference (EMI) shielding performance are significant in alleviating the interference impacts induced from a remarkable variety of devices. In the work, we propose novel sandwich structures for manipulating the EM wave transport, which holds unique EMI shielding features of frequency selectivity. By employing electrical and magnetic loss spacers, the resultant sandwich structures are endowed with tunable EMI shielding performance, showing substantial improvements in overall shielding effectiveness along with pronounced shielding peak shift. The mechanisms suggest that the multiple interfaces, electromagnetic loss media, and changes of representative EM wavelength could be critical roles in tailoring the EMI shielding performance. The results provide a versatile strategy that could be extended in other frequency ranges and various types of sandwich structures, promising great opportunities for designing and fabricating advanced electromagnetic attenuation materials and devices.

  4. Fracture Characterization of Sandwich Face/Core Interfaces

    DEFF Research Database (Denmark)

    Manca, Marcello

    model of the MMB specimen was used to determine the mode-mixityangle. A new testing methodology called G-control was developed in order to enable cyclic crack growth testing of sandwich structures at a constant level of cyclic energy release rate, which is not possible with traditional testing methods......Sandwich structures are nowadays widely used in lightweight structural applications because oftheir superior stiffness/weight and strength/weight ratios compared with traditional metallic as well as monolithic structures made from composite materials. A major limiting factor of wider application...... of sandwich structures is defects that are introduced in the manufacturing process. It is inevitable that areas of the face sheets will not fully adhere to the core resulting in defects known as “debonds”. Debonds can also be induced in-service due to e.g. localised impact loading or overloading. As the means...

  5. Nanocrystalline Aluminum Truss Cores for Lightweight Sandwich Structures

    Science.gov (United States)

    Schaedler, Tobias A.; Chan, Lisa J.; Clough, Eric C.; Stilke, Morgan A.; Hundley, Jacob M.; Masur, Lawrence J.

    2017-12-01

    Substitution of conventional honeycomb composite sandwich structures with lighter alternatives has the potential to reduce the mass of future vehicles. Here we demonstrate nanocrystalline aluminum-manganese truss cores that achieve 2-4 times higher strength than aluminum alloy 5056 honeycombs of the same density. The scalable fabrication approach starts with additive manufacturing of polymer templates, followed by electrodeposition of nanocrystalline Al-Mn alloy, removal of the polymer, and facesheet integration. This facilitates curved and net-shaped sandwich structures, as well as co-curing of the facesheets, which eliminates the need for extra adhesive. The nanocrystalline Al-Mn alloy thin-film material exhibits high strength and ductility and can be converted into a three-dimensional hollow truss structure with this approach. Ultra-lightweight sandwich structures are of interest for a range of applications in aerospace, such as fairings, wings, and flaps, as well as for the automotive and sports industries.

  6. Effect of layer length on deflection in sandwich beams

    Science.gov (United States)

    Abbu, Muthanna A.; AL-Ameri, Riyadh

    2017-09-01

    A theoretical study has been carried out on sandwich beams strengthened mechanically by two external steel plates attached to their tension and compression sides with so-called "shear connectors ". This study is based on the individual behaviour of each component of the composite sandwich section (i.e. reinforced concrete beam and upper steel plate and lower steel plate). The approach has been developed to simulate the behaviour of such beams, and is based on neglecting the separation between the three layers; i.e., the deflections are equal in each element through the same section. The differential equations reached were solved analytically. Deflection was calculated by using the approach for several beams, tested in two series, and close agreements were obtained with the experimental values. Furthermore, the interaction efficiency between the three elements in a composite sandwich beam has been considered thoroughly, from which the effect of some parameters, such as plate length upon the behaviour of such beams, were studied.

  7. Identification of material properties of sandwich structure with piezoelectric patches

    Directory of Open Access Journals (Sweden)

    Zemčík R.

    2008-11-01

    Full Text Available The work focuses on light-weight sandwich structures made of carbon-epoxy skins and foam core which have unique bending stiffness compared to conventional materials. The skins are manufactured by vacuum autoclave technology from unidirectional prepregs and the sandwich is then glued together. The resulting material properties of the structure usually differ from those provided by manufacturer or even those obtained from experimental tests on separate materials, which makes computational models unreliable. Therefore, the properties are identified using the combination of experimental analysis of the sandwich with attached piezoelectric transducer and corresponding static and modal finite element analyses. Simple mathematical optimization with repetitive finite element solution is used. The model is then verified by transient analysis when the piezoelectric patch is excited by harmonic signals covering the first two eigen-frequencies and the induced oscillations are measured by laser sensor.

  8. Study on voids of epoxy matrix composites sandwich structure parts

    Science.gov (United States)

    He, Simin; Wen, Youyi; Yu, Wenjun; Liu, Hong; Yue, Cheng; Bao, Jing

    2017-03-01

    Void is the most common tiny defect of composite materials. Porosity is closely related to composite structure property. The voids forming behaviour in the composites sandwich structural parts with the carbon fiber reinforced epoxy resin skins was researched by adjusting the manufacturing process parameters. The composites laminate with different porosities were prepared with the different process parameter. The ultrasonic non-destructive measurement method for the porosity was developed and verified through microscopic examination. The analysis results show that compaction pressure during the manufacturing process had influence on the porosity in the laminate area. Increasing the compaction pressure and compaction time will reduce the porosity of the laminates. The bond-line between honeycomb core and carbon fiber reinforced epoxy resin skins were also analyzed through microscopic examination. The mechanical properties of sandwich structure composites were studied. The optimization process parameters and porosity ultrasonic measurement method for composites sandwich structure have been applied to the production of the composite parts.

  9. Production and use of thyroxine antisera in radioimmunoassay technique

    International Nuclear Information System (INIS)

    Abbas, Sumaia Hussein

    2000-06-01

    This study describes the production of antisera from sheep and its use in the determination of thyroxine hormone (T 4 ) level in serum using radioimmunoassay (RIA) technique. In this study two local sheep (Ovis aris) were subjected to immunization against human T 4 immunogen, sera obtained from both sheep after each injection were subjected to evaluation through titration in a purified and non purified form. The produced antibodies were used to assemble a kit for the determination of total human serum thyroxine. Different separation techniques were tried, (second antibody polyethylene glycol (PEG) assisted precipitation, polystyrene beads and magnetisable particles solid phases). For the PEG assisted precipitation, local antiserum and that produced by the North East Thamus Region Immunoassay (NETRIA donkey anti-sheep serum (DASS) as second antibodies) were tried. The final dilutions of the anti-T 4 antibody used were 1/4000 in a liquid phase using second antibody PEG assisted separation, 1/3000 using magnetizable particles and a dilution of 1/10,000 using polystyrene beads solid phase for separation. Optimization of T 4 assay conditions including incubation temperature and reaction time were done. Tests for T 4 assay validation (linearity, recovery and responsibility) were carried out. For linearity and recovery tests, the regression coefficient ranges were found to be from (0.8 to 0.9) and (0.88 to 0.98) respectively. The assay was found to be reproducible where the coefficients of variation within and between assays were less than 10%. The locally developed assay was found to be comparable with NETRIA assay as a reference method with a correlation coefficient of 0.88, 0.93 and 0.87 for PEG assisted separation, magnetizable particles and polystyrene beads techniques respectively. The clinical validation tests showed a reliable sensitivity, specificity and efficiency with values of 97%, 94% and 96% respectively. When the T 4 concentrations measured using the

  10. Measurement of plasma 11-deoxycorticosterone levels by radioimmunoassay in man

    International Nuclear Information System (INIS)

    Fukuchi, Soitsu; Nakajima, Katsuo; Takenouchi, Takahiko; Nishisato, Koji

    1974-01-01

    A radioimmunoassay procedure has been developed to measure 11-deoxycorticosterone (DOC) in human peripheral plasma. DOC-oxime was coupled with porcine gamma globulin and antibodies produced in rabbits. One to 3 ml of plasma, with 1, 2 3 H-DOC added for recovery, was extracted with dichloromethane and purification achieved by a silica gel column and by one paper chromatograph. After overnight incubation of the antibody-steroid mixture at 4 0 C, bound and free fractions were separated using ammonium sulfate. The mean recovery of 3 H-DOC, after extraction and chromatography, was 84.6 +- 7.4%. The method showed adequate specificity, precision and accuracy. Normal plasma DOC levels were found to be 4.4 +- 2.5 ng/100 ml (n=8). Plasma DOC levels were almost normal (0.3 - 26.8 ng/100 ml) in fifteen patients with benign essential hypertension. The mean level of 8.1 +- 8.2 ng/100 ml obtained in hypertensive patients with suppressed plasma renin activity, was not significantly different from normal. Plasma DOC showed a high level, 3.0 - 30.5 (11.4 +- 7.5) ng/100 ml, in 9 patients with primary aldosteronism. Four out of 8 patients with Cushing's syndrome were found to have elevated plasma DOC levels. Higher levels of 21.2 +- 15.8 ng/100 ml were found in 5 patients with adrenal hyperplasia than those of 12.3 +- 8.0 ng/100 ml in 3 with adrenal adenoma. Plasma DOC levels were high, 113 - 176 ng/100 ml, in 2 patients with 17α-hydroxylase deficiency. ACTH administered to 5 subjects produced a mean increase in plasma DOC from 4.8 to 25.8 ng/100 ml. Angiotensin II infused at a rate of 10 ng/kg/min for 30 min into 4 subjects did not increase mean plasma DOC. Similarly, dietary sodium restriction or postural change did not increase plasma DOC. (auth.)

  11. The radioimmunoassay of plasma oxytocin in pregnancy and at parturition

    International Nuclear Information System (INIS)

    Kogure, Satohisa

    1976-01-01

    The titer of the antiserum obtained by inoculating oxytocin-bovine serum albumin antigen into mature male rabbits was 1:64,000 in the final dilution, and the rate of conjugation with labeled-oxytocin was 34%. The cross reaction rate of the antiserum was 0.01% or below, both for lysine vasopressin and arginine vasopressin. The sensitivity of the radioimmunoassay using this antiserum was 5μIU. When a known quantity of oxytocin was added to plasma for measurement, the mean recovery rate was about 93%. The blood oxytocin concentration was 6.1+-2.5μIU/ml (ml omitted hereafter) in the early stage of pregnancy, 12.5+-6.0μIU in the middle stage, and 27.0+-7.5μIU in the terminal stage. The oxytocin concentration in the maternal blood was 34.1+-4.9μIU in the second stage, the concentration in the umbilical arterial blood immediately after delivery 3.5+-5.3μIU, and that in the umbilical venous blood 30.0+-4.2μIU. In cases of caesarean section not in labor, the oxytocin concentration in the maternal blood was 27.1+-6.6μIU, that in the umbilical arterial blood 25.1+-5.4μIU, and that in the umbilical venous blood 25.4+-5.4μIU. In cases of caesarean section in labor, the oxytocin concentration in the maternal blood was 37.1+-7.1μIU, that in the umbilical arterial blood 31.4+-6.7μIU, and that in the umbilical venous blood 27.0+-7.8μIU. The half-life of the oxytocin in the peripheral blood in cases injected with oxytocin was 5-10 minutes. When prostaglandin F2α was administered intravenously, the oxytocin concentration in the peripheral blood was increased in cases in labor. (Chiba, N.)

  12. Sandwich enzyme-linked immunosorbent assay for naringin.

    Science.gov (United States)

    Qu, Huihua; Wang, Xueqian; Qu, Baoping; Kong, Hui; Zhang, Yue; Shan, Wenchao; Cheng, Jinjun; Wang, Qingguo; Zhao, Yan

    2016-01-15

    Among the currently used immunoassay techniques, sandwich ELISA exhibits higher specificity, lower cross-reactivity, and a wider working range compared to the corresponding competitive assays. However, it is difficult to obtain a pair of antibodies that can simultaneously bind to two epitopes of a molecule with a molecular weight of less than 1000 Da. Naringin (Nar) is a flavonoid with a molecular mass of 580 Da. The main aim of this study was to develop a sandwich ELISA for detecting Nar. Two hybridomas secreting anti-Nar monoclonal antibodies (mAbs) were produced by fusing splenocytes from a mouse immunised against Nar-bovine serum albumin (BSA) conjugated with a hypoxanthine-aminopterin-thymidine (HAT)-sensitive mouse myeloma cell line; a sandwich ELISA for detecting Nar was developed using these two well-characterised anti-Nar mAbs. The performance of the sandwich assay was further evaluated by limit of detection (LOD), limit of quantification (LOQ), recovery, and interference analyses. A dose-response curve to Nar was obtained with an LOD of 6.78 ng mL(-1) and an LOQ of 13.47 ng mL(-1). The inter-assay and intra-assay coefficients of variation were 4.32% and 7.48%, respectively. The recovery rate of Nar from concentrated Fructus aurantii granules was 83.63%. A high correlation was obtained between HPLC and sandwich ELISA. These results demonstrate that the sandwich ELISA method has higher specificity for Nar than indirect competitive ELISA. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Successful mouse hepatocyte culture with sandwich collagen gel formation

    Science.gov (United States)

    Choi, Hyun Jung

    2013-01-01

    Purpose Primary mammalian hepatocytes largely retain their liver-specific functions when they are freshly derived from donors. However, long-term cultures of functional hepatocytes are difficult to establish. To increase the longevity and maintain the differentiated functions of hepatocytes in primary culture, cells can be cultured in a sandwich configuration of collagen. In such a configuration, hepatocytes can be cultured for longer periods compared with cultures on single layers of collagen. However, research regarding mouse hepatocytes in sandwich culture is lacking. Methods Primary mouse hepatocytes were sandwiched between two layers of collagen to maintain the stability of their liver-specific functions. After gelation, 2 mL of hepatocyte culture medium was applied. Results After 24 hours, 5, 10 days of culture, the collagen gel sandwich maintained the cellular border and numbers of bile canaliculi more efficiently than a single collagen coating in both high and low density culture dishes. Reverse transcription-polymerase chain reaction analysis of alpha-1-antitrypsin (AAT), hepatocyte nuclear factor 4 alpha (HNF4A), alphafetoprotein, albumin, tryptophan oxygenase (TO), the tyrosine aminotransferase gene, glucose-6-phosphatase, glyceraldehyde-3-phosphate dehydrogenase for mouse primary hepatocytes cultured on collagen coated dishes and collagen gels showed superior hepatocyte-related gene expression in cells grown using the collagen gel sandwich culture system. AAT, HNF4A, albumin, TO were found to be expressed in mouse hepatocytes cultured on collagen gels for 5 and 10 days. In contrast, mouse hepatocytes grown on collagen-coated dishes did not express these genes after 5 and 10 days of culture. Conclusion The collagen gel sandwich method is suitable for primary culture system of adult mouse hepatocytes. PMID:23577314

  14. Sandwich assay for tacrolimus using 2 antitacrolimus antibodies.

    Science.gov (United States)

    Wei, Tie Q; Zheng, Yi F; Dubowy, Michael; Sharma, Manoj

    2014-04-01

    Although detection of natural haptens by antihapten antibodies in sandwich assay format has the theoretical advantages of high analytical specificity and sensitivity, this type of assay has not been reported because of the seemingly insurmountable task of avoiding steric hindrance between the 2 bindings. This is especially true for ring-structured hydrophobic haptens. The macrolide drug tacrolimus (FK506, Prograf®, 804 Da) is such a hapten. Here we show the detection of tacrolimus using 2 antitacrolimus monoclonal antibodies in a sandwich assay. Both antibodies were developed by use of an intact tacrolimus molecule covalently linked to a carrier protein but via 2 different positions separated by 10 carbon atoms. Epitope analysis based on drug analog binding was used to show no overlap between the binding sites of the 2 antibodies, indicating the 10-carbon separation resulted in 2 distinct epitopes. The distinct epitopes suggested that the drug might be approachable by the antibodies from 2 separate directions, which predicted simultaneous binding as in sandwich formation. This prediction was confirmed in sandwich ELISA and affinity column-mediated immunoassay formats. The assay demonstrated good imprecision and significantly lower metabolite cross-reactivity than competitive assay counterparts. Comparison with liquid chromatography-tandem mass spectrometry (LC-MS/MS) using 55 whole-blood samples from transplant patients with tacrolimus concentrations ranging from 0.9 to 29.5 ng/mL showed a linear regression: sandwich = 0.99 × LC-MS/MS + 0.10 ng/mL, r = 0.991, Sy|x = 1.08 ng/mL. This work demonstrates that a highly specific sandwich assay using 2 antihapten antibodies is feasible for the measurement of a hapten drug.

  15. Structural Performance of Eco-Core Sandwich Panels

    Science.gov (United States)

    Shivakumar, Kunigal; Chen, Huanchun

    Eco-Core, a fire resistant core material for sandwich composite structures developed under the US Navy (ONR) program, was used to study its performance as a sandwich beam with glass/vinyl ester face sheet. Performance of Eco-Core was compared with balsa and PVC core sandwich panels. Test specimens were designed to simulate shear, flexural, and edgewise compression loadings. These tests were conducted on Eco-Core as well as balsa and PVC sandwich composite specimens. Failure loads and modes were compared with each other and the analytical prediction. Both Eco-Core and balsa cored sandwich beams had similar failure modes in all three test conditions. In the case of transversely loaded (four-point) beams Eco-Core specimens failed by core shear for span/depth (S/d) ratio less than 4 and the failure mode changed to core tension for S/d >4. This is attributed to weak tensile strength of the core material. An expression for core tension failure load based on beam theory was derived. On the other hand, ductile materials like PVC failed by core indentation. Under edgewise compression, face sheet microbuckling and general buckling are the two potential failure modes for Eco-Core and balsa core sandwich composites. For specimen length/depth ratio L/d buckling, and for L/d >13 the failure is by general buckling. Predictions from the existing equations agreed well with the experiment for both core materials. For PVC core, wrinkling/shear buckling and general buckling are the potential failure modes. For L/d ≤8.5 the failure is wrinkling and for L/d >8.5 the failure is general buckling.

  16. Methods for Using Durable Adhesively Bonded Joints for Sandwich Structures

    Science.gov (United States)

    Smeltzer, Stanley S., III (Inventor); Lundgren, Eric C. (Inventor)

    2016-01-01

    Systems, methods, and apparatus for increasing durability of adhesively bonded joints in a sandwich structure. Such systems, methods, and apparatus includes an first face sheet and an second face sheet as well as an insert structure, the insert structure having a first insert face sheet, a second insert face sheet, and an insert core material. In addition, sandwich core material is arranged between the first face sheet and the second face sheet. A primary bondline may be coupled to the face sheet(s) and the splice. Further, systems, methods, and apparatus of the present disclosure advantageously reduce the load, provide a redundant path, reduce structural fatigue, and/or increase fatigue life.

  17. Friction stir welding (FSW of aluminium foam sandwich panels

    Directory of Open Access Journals (Sweden)

    M. Bušić

    2016-07-01

    Full Text Available The article focuses on the influence of welding speed and tool tilt angle upon the mechanical properties at the friction stir welding of aluminium foam sandwich panels. Double side welding was used for producing butt welds of aluminium sandwich panels applying insertion of extruded aluminium profile. Such insertion provided lower pressure of the tool upon the aluminium panels, providing also sufficient volume of the material required for the weldment formation. Ultimate tensile strength and flexural strength for three-point bending test have been determined for samples taken from the welded joints. Results have confirmed anticipated effects of independent variables.

  18. Application of fibre reinforced plastic sandwich structures for automotive crashworthiness applications

    NARCIS (Netherlands)

    Lukaszewicz, D.; Blok, L.G.; Kratz, J.; Ward, C.; Kassapoglou, C.; Elmarakbi, A.; Araújo, A.L.

    2016-01-01

    In this work the application of fibre reinforced plastic (FRP) sandwich
    structures, with particular focus on aramid fibre tufted sandwiches is being studied for
    automotive crashworthiness applications using impact testing and numerical simulation.

  19. Radioimmunoassay of plasma corticotropin in the edible Frog Rana esculenta L

    International Nuclear Information System (INIS)

    Vaudry, Hubert; Leboulenger, Francois; Dupont, Willy; Vaillant, Rene

    1975-01-01

    In the green Frog (Rana esculenta) the plasma contains a polypeptide immunologically related to human and porcine corticotropins. A radioimmunoassay capable of detecting 4.10 -12 g hog ACTH has been used for a direct plasma ACTH assay in the Frog. Using this method the ACTH rate was determined both in untreated frogs and in animals under various experimental conditions [fr

  20. Method for the optimum formation of angiotensin I from angiotensinogen and radioimmunoassay for angiotensin I

    International Nuclear Information System (INIS)

    Pagnucco, R.G.; Murty, D.R.; Muse, R.J.

    1978-01-01

    The invention deals with a method to optimize the formation of angiotensin I from angiotensinogens by optimizing the temperature, pH value and buffer system. Furthermore, the invention concerns a radioimmunoassay method to determine angiotensin I. Iodine 125 labelled angiotensin I is preferably used as tracer. (VJ) [de

  1. 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

  2. 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.)

  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. A novel radioimmunoassay of 7-oxo-DHEA and its physiological levels

    Czech Academy of Sciences Publication Activity Database

    Kazihnitová, H.; Zamrazilová, L.; Hill, M.; Lapčík, O.; Pouzar, Vladimír; Hampl, R.

    2007-01-01

    Roč. 72, č. 4 (2007), s. 342-350 ISSN 0039-128X Grant - others:GA MZd(CZ) NR7815 Institutional research plan: CEZ:AV0Z40550506 Keywords : 7-oxo-dehydroepiandrosterone * radioimmunoassay * GC-MS * serum levels Subject RIV: CC - Organic Chemistry Impact factor: 2.143, year: 2007

  5. Preparation, purification and characterization of 125I-glucagon used for radioimmunoassay

    International Nuclear Information System (INIS)

    Ruehlmann, C.; Poege, A.; Stollmaier, P.; Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1988-01-01

    A method for the radioactive labelling of glucagon with Na 125 I with the help of chloramine T for the use in radioimmunoassay is described. The purification of 125 I-glucagon with polyacrylamide gel electrophoresis, the characterization of the tracer, its stability and the immunological properties are described. (author)

  6. Comparison of luteinizing hormone and human chorionic gonadotrophin determinations by biological, radioreceptor and radioimmunoassay methods

    International Nuclear Information System (INIS)

    Lange, E.; Paszko, Z.; Padzik, H.

    1980-01-01

    A comparison of the radioreceptor method of assaying LH and HCG with the biological and radioimmunoassay methods is carried out on several preparations of gonadotrophins: human pituitary luteinizing hormone, human menopausal gonadotrophin and human chorionic gonadotrophin. The radioreceptor method better reflects the biological properties of hormones than the radioimmunological method. (author)

  7. Simultaneous detection of Hepatitis B surface antigen and its antibody by radioimmunoassay

    International Nuclear Information System (INIS)

    Crouzat-Reynes, Gerard; Perigois, Francois; Lecureuil, Michel; Lejeune, Bernard

    1981-01-01

    The authors describe an original radioimmunoassay which allows the simultaneous detection of hepatitis B surface antigen and its antibody in a biological sample. Antigen and antibody are indiscriminately detected in a first step and then distinguished in a second step using the same reagents [fr

  8. Filter radioimmunoassay, a method for large-scale serotyping of Neisseria meningitidis.

    NARCIS (Netherlands)

    S. de Marie (Siem); J.H.J. Hoeijmakers (Jan); J.T. Poolman; H.C. Zanen

    1984-01-01

    textabstractA simple and rapid filter radioimmunoassay method can be used to serotype meningococcal strains on a large scale. The technique consists of simultaneous inoculation of 96 strains on nitrocellulose filters. The resulting colonies can be processed in situ, by extraction and fixation,

  9. Elevated serum free thyroxine by thyroxine analog radioimmunoassays in euthyroid patients with familial dysalbuminemic hyperthyroxinemia

    International Nuclear Information System (INIS)

    Rajatanavin, R.; Fournier, L.; DeCosimo, D.; Abreau, C.; Braverman, L.E.

    1982-01-01

    A study was done to ascertain whether the serum free T4 measured by free T4 radioimmunoassay kits would, like equilibrium dialysis, be normal in patients with familial dysalbuminemic hyperthyroxinemia. Five free T4 radioimmunoassay kits were used to measure free T4 in serum samples from 19 patients with familial dysalbuminemic hyperthyroxinemia and 20 healthy volunteers. Values (mean +/- SE) for T4, free T4 index, and free T4 (equilibrium dialysis) in these normal subjects and patients with familial dysalbuminemic hyperthyroxinemia, respectively, were as follows: T4, 8.1 +/- 0.2 and 18.3 +/- 0.7 μg/dL; free T4 index, 3.1 +/- 0.1 and 7.3 +/- 0.3 μg/dL; free T4, 1.4 +/- 0.1 and 1.2 +/- 0.1 ng/dL. The following free T4 radioimmunoassay methods were used: antibody coated microfine silica, microencapsulated antibody, two-step antibody-coated tube, and one-step 125 I-T4 analog (2 kits). The present findings in patients with familial dysalbuminemic hyperthyroxinemia and previous observations in ill euthyroid patients suggest that serum free T4 measured by some radioimmunoassay methods must be interpreted with caution in these two clinical situations

  10. Radioimmunoassay for bupropion in human plasma: comparison of tritiated and iodinated radioligands

    Energy Technology Data Exchange (ETDEWEB)

    Butz, R.F.; Smith, P.G.; Schroeder, D.H.; Findlay, J.W.

    1983-03-01

    We evaluated the potential usefulness of /sup 125/I-labeled p-hydroxybupropion in a direct radioimmunoassay for bupropion in human plasma as compared with a currently used (/sup 3/H)bupropion dextran-coated charcoal method. In both radioimmunoassay methods succinoylpropylbupropion antiserum was used that was highly specific for unchanged drug, cross reactivities with known bupropion metabolites being less than 0.3%. However, the use of /sup 125/I-labeled p-hydroxybupropion afforded greater sensitivity (0.3 microgram/L vs 0.6 microgram/L with (/sup 3/H)bupropion) and was readily adaptable to the more convenient polyethylene glycol separation method. Between-assay CVs were 3.8 to 12.2% (mean 7.6%) with the /sup 125/I-based radioimmunoassay and 5.1 to 11.5% (mean 7.5%) with the /sup 3/H-based assay. Agreement between the two radioimmunoassay determinations of buproprion in human plasma samples collected over a 60-h period after oral drug administration was excellent (slope . 1.086, r . 0.989). We find the /sup 125/I-based assay a convenient and suitable alternative to the (/sup 3/H)bupropion assay in pharmacokinetic studies in humans.

  11. Radioimmunoassay for bupropion in human plasma: comparison of tritiated and iodinated radioligands.

    Science.gov (United States)

    Butz, R F; Smith, P G; Schroeder, D H; Findlay, J W

    1983-03-01

    We evaluated the potential usefulness of 125I-labeled p-hydroxybupropion in a direct radioimmunoassay for bupropion in human plasma as compared with a currently used [3H]bupropion dextran-coated charcoal method. In both radioimmunoassay methods succinoylpropylbupropion antiserum was used that was highly specific for unchanged drug, cross reactivities with known bupropion metabolites being less than 0.3%. However, the use of 125I-labeled p-hydroxybupropion afforded greater sensitivity (0.3 microgram/L vs 0.6 microgram/L with [3H]bupropion) and was readily adaptable to the more convenient polyethylene glycol separation method. Between-assay CVs were 3.8 to 12.2% (mean 7.6%) with the 125I-based radioimmunoassay and 5.1 to 11.5% (mean 7.5%) with the 3H-based assay. Agreement between the two radioimmunoassay determinations of buproprion in human plasma samples collected over a 60-h period after oral drug administration was excellent (slope = 1.086, r = 0.989). We find the 125I-based assay a convenient and suitable alternative to the [3H]bupropion assay in pharmacokinetic studies in humans.

  12. Radio-immunoassays for glucagon-like peptides 1 and 2 (GLP-1 and GLP-2)

    DEFF Research Database (Denmark)

    Orskov, C; Holst, J J

    1987-01-01

    Gene-sequencing studies have shown that the glucagon precursor contains two additional glucagon-like sequences, the so-called glucagon-like peptides 1 and 2 (GLP-1 and GLP-2). We developed radio-immunoassays against synthetic peptides corresponding to these sequences. Antisera were raised in rabb...

  13. Conditions and limits of serum LH radioimmunoassay in normal, hypophysectomised or castred rats

    International Nuclear Information System (INIS)

    Andre, M.; Boucher, D.; Thieblot, L.

    1976-01-01

    Serum LH was measured by radioimmunoassay (NIAMD Kits) free and linked hormones were separated by double antibodies method. Influence of concentration on antibody-hormone complex is studied. Hypophysectomised rats serum does not modify results. The standard (rat LH-RPl) has the same action as serum LH. Rat serum LH contents are measured in normal or castred rats [fr

  14. Stabilization of nonlinear sandwich systems via state feedback-Discrete-time systems

    NARCIS (Netherlands)

    Wang, Xu; Stoorvogel, Antonie Arij; Saberi, Ali; Grip, H°avard Fjær; Sannuti, Peddapullaiah

    2011-01-01

    A recent paper (IEEE Trans. Aut. Contr. 2010; 55(9):2156–2160) considered stabilization of a class of continuous-time nonlinear sandwich systems via state feedback. This paper is a discrete-time counterpart of it. The class of nonlinear sandwich systems consists of saturation elements sandwiched

  15. Energy Dissipation in Sandwich Structures During Axial Compression

    DEFF Research Database (Denmark)

    Urban, Jesper

    2002-01-01

    -scale structural elements in fast sandwich vessels. Two of the crushing tests are simulated with the explicit finite element software LS-DYNA3D. The key results are load-end shortening relationship and the energy dissipation. Good agreement between the numerical predictions and the experiments are obtained...

  16. A Debonded Sandwich Specimen Under Mixed Mode Bending (MMB)

    DEFF Research Database (Denmark)

    Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

    2008-01-01

    for the MMB specimen were derived from a superposition analysis. An experimental verification of the methodology proposed was performed using MMB sandwich specimens with H100 PVC foam core and E-glass/polyester non-crimp quadro-axial [0/45/90/-45]s DBLT-850 faces. Different mixed mode loadings were applied...

  17. Stabilization of a class of sandwich systems via state feedback

    NARCIS (Netherlands)

    Wang, Xu; Stoorvogel, Antonie Arij; Saberi, Ali; Grip, H°avard Fjær; Roy, Sandip; Sannuti, Peddapullaiah

    We consider the problem of state-feedback stabilization for a class of sandwich systems, consisting of two linear systems connected in cascade via a saturation. In particular, we present design methodologies for constructing semiglobally and globally stabilizing controllers for such systems when the

  18. Effect of Physical Nonlinearity on Local Buckling in Sandwich Beams

    NARCIS (Netherlands)

    Koysin, V.; Shipsha, Andrey; Skvortsov, Vitaly

    2010-01-01

    This article deals with experimental, theoretical, and FE characterization of the local buckling in foam-core sandwich beams. In the theoretical approach, this phenomena is considered in a periodic formulation (unbounded wrinkle wave); a nonlinear stress—strain response of the face material is

  19. An Assessment of the Speed Reading Ability of Sandwich Students ...

    African Journals Online (AJOL)

    The paper discusses the concept and usefulness of rapid reading. It also reports a study in which the Faculty of Education, University of Lagos, Nigeria Sandwich students formed the subjects. Their pre-training reading speed and comprehension scores were determined through a pre-test, after which they were subjected to ...

  20. Factors that Influence Information Seeking Behaviour of Sandwich ...

    African Journals Online (AJOL)

    This study examined the factors that influence the information seeking behavior of sandwich students in selected Nigerian Univ ersities. Questionnaire was used to collect data with a response rate of (97.30%). Among the factors that influence information seeking is availability of internet resources in or near the library; ...

  1. Factors that Influence Information Seeking Behaviour of Sandwich ...

    African Journals Online (AJOL)

    This study examined the factors that influence the information seeking behavior of sandwich students in selected Nigerian Universities. Questionnaire was used to collect data with a response rate of (97.30%). Among the factors that influence information seeking is availability of internet resources in or near the library; ...

  2. Damage assessment of compression loaded debond damaged sandwich panels

    DEFF Research Database (Denmark)

    Moslemian, Ramin; Berggreen, Christian; Quispitupa, Amilcar

    2010-01-01

    with an implanted circular face/core debond. Compression tests were conducted on intact sandwich panels and panels with an implanted circular face/core debond with three different types of foam core materials (PVC H130, PVC H250 and PMI 51-IG). The strains and out-of-plane displacements of the debonded region were...

  3. Investigation on Wall Panel Sandwiched With Lightweight Concrete

    Science.gov (United States)

    Lakshmikandhan, K. N.; Harshavardhan, B. S.; Prabakar, J.; Saibabu, S.

    2017-08-01

    The rapid population growth and urbanization have made a massive demand for the shelter and construction materials. Masonry walls are the major component in the housing sector and it has brittle characteristics and exhibit poor performance against the uncertain loads. Further, the structure requires heavier sections for carrying the dead weight of masonry walls. The present investigations are carried out to develop a simple, lightweight and cost effective technology for replacing the existing wall systems. The lightweight concrete is developed for the construction of sandwich wall panel. The EPS (Expanded Polystyrene) beads of 3 mm diameter size are mixed with concrete and developed a lightweight concrete with a density 9 kN/m3. The lightweight sandwich panel is cast with a lightweight concrete inner core and ferrocement outer skins. This lightweight wall panel is tested for in-plane compression loading. A nonlinear finite element analysis with damaged plasticity model is carried out with both material and geometrical nonlinearities. The experimental and analytical results were compared. The finite element study predicted the ultimate load carrying capacity of the sandwich panel with reasonable accuracy. The present study showed that the lightweight concrete is well suitable for the lightweight sandwich wall panels.

  4. Shear properties evaluation of a truss core of sandwich beams

    Science.gov (United States)

    Wesolowski, M.; Ludewicz, J.; Domski, J.; Zakrzewski, M.

    2017-10-01

    The open-cell cores of sandwich structures are locally bonded to the face layers by means of adhesive resin. The sandwich structures composed of different parent materials such as carbon fibre composites (laminated face layers) and metallic core (aluminium truss core) brings the need to closely analyse their adhesive connections which strength is dominated by the shear stress. The presented work considers sandwich beams subjected to the static tests in the 3-point bending with the purpose of estimation of shear properties of the truss core. The main concern is dedicated to the out-of plane shear modulus and ultimate shear stress of the aluminium truss core. The loading of the beam is provided by a static machine. For the all beams the force - deflection history is extracted by means of non-contact optical deflection measurement using PONTOS system. The mode of failure is identified for each beam with the corresponding applied force. A flexural rigidity of the sandwich beams is also discussed based on force - displacement plots.

  5. Outcome of the TURP-TUVP sandwich procedure for minimally ...

    African Journals Online (AJOL)

    Bladder neck stenosis occurred in 3 patients and was successfully treated with bladder neck incision. Conclusions: The sandwich combination of TURP and TUVP for the surgical treatment of BPH with volume larger than 40cc had satisfactory patient safety profile and resulted in significant improvement in IPSS, Qmax and ...

  6. Mechanical Behavior of CFRP Lattice Core Sandwich Bolted Corner Joints

    Science.gov (United States)

    Zhu, Xiaolei; Liu, Yang; Wang, Yana; Lu, Xiaofeng; Zhu, Lingxue

    2017-12-01

    The lattice core sandwich structures have drawn more attention for the integration of load capacity and multifunctional applications. However, the connection of carbon fibers reinforced polymer composite (CFRP) lattice core sandwich structure hinders its application. In this paper, a typical connection of two lattice core sandwich panels, named as corner joint or L-joint, was investigated by experiment and finite element method (FEM). The mechanical behavior and failure mode of the corner joints were discussed. The results showed that the main deformation pattern and failure mode of the lattice core sandwich bolted corner joints structure were the deformation of metal connector and indentation of the face sheet in the bolt holes. The metal connectors played an important role in bolted corner joints structure. In order to save the calculation resource, a continuum model of pyramid lattice core was used to replace the exact structure. The computation results were consistent with experiment, and the maximum error was 19%. The FEM demonstrated the deflection process of the bolted corner joints structure visually. So the simplified FEM can be used for further analysis of the bolted corner joints structure in engineering.

  7. Enhanced detection levels in a semi-automated sandwich ...

    African Journals Online (AJOL)

    A peptide nucleic acid (PNA) signal probe was tested as a replacement for a typical DNA oligonucleotidebased signal probe in a semi-automated sandwich hybridisation assay designed to detect the harmful phytoplankton species Alexandrium tamarense. The PNA probe yielded consistently higher fluorescent signal ...

  8. Bending and Deformation of Sandwich Panels Due to Localized Pressure

    Directory of Open Access Journals (Sweden)

    Bambang K. Hadi

    2005-05-01

    Full Text Available Bending and deformation of sandwich panels due to localized pressure were analyzed using both Rayleigh-Ritz and finite element methods. The faces were made of laminated composite plates, while the core was a honeycomb material. Carbon fiber and glass fiber reinforced plastics were used for composite plate faces. In the case of Rayleigh-Ritz method, first the total energy of the system was calculated and then taking the variations of the total energy, the sandwich panel deflections could be computed. The deflections were assumed by means of Fourier series. A finite element code NASTRAN was exploited extensively in the finite element method. 3-dimensional 8-node brick elements were used to model sandwich panels, for both the faces sheets and the core. The results were then compared to each other and in general they are in good agreements. Dimple phenomena were found in these cases. It shows that localized pressure on sandwich structures will produce dimple on the pressurize region with little effects on the rest of the structures.

  9. Compressive Behaviour and Energy Absorption of Aluminium Foam Sandwich

    Science.gov (United States)

    Endut, N. A.; Hazza, M. H. F. Al; Sidek, A. A.; Adesta, E. T. Y.; Ibrahim, N. A.

    2018-01-01

    Development of materials in automotive industries plays an important role in order to retain the safety, performance and cost. Metal foams are one of the idea to evolve new material in automotive industries since it can absorb energy when it deformed and good for crash management. Recently, new technology had been introduced to replace metallic foam by using aluminium foam sandwich (AFS) due to lightweight and high energy absorption behaviour. Therefore, this paper provides reliable data that can be used to analyze the energy absorption behaviour of aluminium foam sandwich by conducting experimental work which is compression test. Six experiments of the compression test were carried out to analyze the stress-strain relationship in terms of energy absorption behavior. The effects of input variables include varying the thickness of aluminium foam core and aluminium sheets on energy absorption behavior were evaluated comprehensively. Stress-strain relationship curves was used for energy absorption of aluminium foam sandwich calculation. The result highlights that the energy absorption of aluminium foam sandwich increases from 12.74 J to 64.42 J respectively with increasing the foam and skin thickness.

  10. Transfer hydrogenation reactions catalyzed by chiral half-sandwich ...

    Indian Academy of Sciences (India)

    Chiral ruthenium half-sandwich complexes were prepared using a chelating diamine made from proline with a phenyl, ethyl, or benzyl group, instead of hydrogen on one of the coordinating arms. Three of these complexes were obtained as single diastereoisomers and their configuration identified by X-ray crystallography.

  11. Effect of microencapsulated phase change material in sandwich panels

    Energy Technology Data Exchange (ETDEWEB)

    Castellon, Cecilia; Medrano, Marc; Roca, Joan; Cabeza, Luisa F. [GREA Innovacio Concurrent, Edifici CREA, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain); Navarro, Maria E.; Fernandez, Ana I. [Departamento de Ciencias de los Materiales e Ingenieria Metalurgica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Lazaro, Ana; Zalba, Belen [Instituto de Investigacion en Ingenieria de Aragon, I3A, Grupo de Ingenieria Termica y Sistemas Energeticos (GITSE), Dpto. Ingenieria Mecanica, Area de Maquinas y Motores Termicos, Universidad de Zaragoza, Campus Politecnico Rio Ebro, Edificio ' ' Agustin de Betancourt,' ' Maria de Luna s/n, 50018 Zaragoza (Spain)

    2010-10-15

    Sandwich panels are a good option as building materials, as they offer excellent characteristics in a modular system. The goal of this study was to demonstrate the feasibility of using the microencapsulated PCM (Micronal BASF) in sandwich panels to increase their thermal inertia and to reduce the energy demand of the final buildings. In this paper, to manufacture the sandwich panel with microencapsulated PCM three different methods were tested. In case 1, the PCM was added mixing the microencapsulated PCM with one of the components of the polyurethane. In the other two cases, the PCM was added either a step before (case 2) or a step after (case 3) to the addition of the polyurethane to the metal sheets. The results show that in case 1 the effect of PCM was overlapped by a possible increase in thermal conductivity, but an increase of thermal inertia was found in case 3. In case 2, different results were obtained due to the poor distribution of the PCM. Some samples showed the effect of the PCM (higher thermal inertia), and other samples results were similar to the conventional sandwich panel. In both cases (2 and 3), it is required to industrialize the process to improve the results. (author)

  12. Flexural Behavior of Aluminum Honeycomb Core Sandwich Structure

    Science.gov (United States)

    Matta, Vidyasagar; Kumar, J. Suresh; Venkataraviteja, Duddu; Reddy, Guggulla Bharath Kumar

    2017-05-01

    This project is concerned with the fabrication and flexural testing of aluminium honey comb sandwich structure which is a special case of composite materials that is fabricated by attaching two thin but stiff skins to a light weight but thick core. The core material is normally low density material but its high thickness provide the sandwich composite with high bonding stiffness. Honeycomb core are classified into two types based on the materials and structures. Hexagonal shape has a unique properties i.e has more bonding strength and less formation time based on the cell size and sheet thickness. Sandwich structure exhibit different properties such as high load bearing capacity at low weight and has excellent thermal insulation. By considering the above properties it has tendency to minimize the structural problem. So honey comb sandwich structure is choosed. The core structure has a different applications such as aircraft, ship interiors, construction industries. As there is no proper research on strength characteristics of sandwich structure. So, we use light weight material to desire the strength. There are different parameters involved in this structure i.e cell size, sheet thickness and core height. In this project we considered 3 level of comparison among the 3 different parameters cell size of 4, 6 and 8 mm, sheet thickness of 0.3, 0.5 and 0.7 mm, and core height of 20,25 and 30 mm. In order to reduce the number of experiment we use taguchi design of experiment, and we select the L8 orthogonal array is the best array for this type of situation, which clearly identifies the parameters by independent of material weight to support this we add the minitab software, to identify the main effective plots and regression equation which involves the individual response and corresponding parameters. Aluminium material is used for the fabrication of Honeycomb sandwich structure among the various grades of aluminium we consider the AL6061 which is light weight material

  13. Compressive strength after blast of sandwich composite materials.

    Science.gov (United States)

    Arora, H; Kelly, M; Worley, A; Del Linz, P; Fergusson, A; Hooper, P A; Dear, J P

    2014-05-13

    Composite sandwich materials have yet to be widely adopted in the construction of naval vessels despite their excellent strength-to-weight ratio and low radar return. One barrier to their wider use is our limited understanding of their performance when subjected to air blast. This paper focuses on this problem and specifically the strength remaining after damage caused during an explosion. Carbon-fibre-reinforced polymer (CFRP) composite skins on a styrene-acrylonitrile (SAN) polymer closed-cell foam core are the primary composite system evaluated. Glass-fibre-reinforced polymer (GFRP) composite skins were also included for comparison in a comparable sandwich configuration. Full-scale blast experiments were conducted, where 1.6×1.3 m sized panels were subjected to blast of a Hopkinson-Cranz scaled distance of 3.02 m kg(-1/3), 100 kg TNT equivalent at a stand-off distance of 14 m. This explosive blast represents a surface blast threat, where the shockwave propagates in air towards the naval vessel. Hopkinson was the first to investigate the characteristics of this explosive air-blast pulse (Hopkinson 1948 Proc. R. Soc. Lond. A 89, 411-413 (doi:10.1098/rspa.1914.0008)). Further analysis is provided on the performance of the CFRP sandwich panel relative to the GFRP sandwich panel when subjected to blast loading through use of high-speed speckle strain mapping. After the blast events, the residual compressive load-bearing capacity is investigated experimentally, using appropriate loading conditions that an in-service vessel may have to sustain. Residual strength testing is well established for post-impact ballistic assessment, but there has been less research performed on the residual strength of sandwich composites after blast.

  14. The Planar Sandwich and Other 1D Planar Heat Flow Test Problems in ExactPack

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, Jr., Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-24

    This report documents the implementation of several related 1D heat flow problems in the verification package ExactPack [1]. In particular, the planar sandwich class defined in Ref. [2], as well as the classes PlanarSandwichHot, PlanarSandwichHalf, and other generalizations of the planar sandwich problem, are defined and documented here. A rather general treatment of 1D heat flow is presented, whose main results have been implemented in the class Rod1D. All planar sandwich classes are derived from the parent class Rod1D.

  15. Elastic stability of superplastically formed/diffusion-bonded orthogonally corrugated core sandwich plates

    Science.gov (United States)

    Ko, W. L.

    1980-01-01

    The paper concerns the elastic buckling behavior of a newly developed superplastically formed/diffusion-bonded (SPF/DB) orthogonally corrugated core sandwich plate. Uniaxial buckling loads were calculated for this type of sandwich plate with simply supported edges by using orthotropic sandwich plate theory. The buckling behavior of this sandwich plate was then compared with that of an SPF/DB unidirectionally corrugated core sandwich plate under conditions of equal structural density. It was found that the buckling load for the former was considerably higher than that of the latter.

  16. Evaluation of a Single-Beam Sonar System to Map Seagrass at Two Sites in Northern Puget Sound, Washington

    Science.gov (United States)

    Stevens, Andrew W.; Lacy, Jessica R.; Finlayson, David P.; Gelfenbaum, Guy

    2008-01-01

    Seagrass at two sites in northern Puget Sound, Possession Point and nearby Browns Bay, was mapped using both a single-beam sonar and underwater video camera. The acoustic and underwater video data were compared to evaluate the accuracy of acoustic estimates of seagrass cover. The accuracy of the acoustic method was calculated for three classifications of seagrass observed in underwater video: bare (no seagrass), patchy seagrass, and continuous seagrass. Acoustic and underwater video methods agreed in 92 percent and 74 percent of observations made in bare and continuous areas, respectively. However, in patchy seagrass, the agreement between acoustic and underwater video was poor (43 percent). The poor agreement between the two methods in areas with patchy seagrass is likely because the two instruments were not precisely colocated. The distribution of seagrass at the two sites differed both in overall percent vegetated and in the distribution of percent cover versus depth. On the basis of acoustic data, seagrass inhabited 0.29 km2 (19 percent of total area) at Possession Point and 0.043 km2 (5 percent of total area) at the Browns Bay study site. The depth distribution at the two sites was markedly different. Whereas the majority of seagrass at Possession Point occurred between -0.5 and -1.5 m MLLW, most seagrass at Browns Bay occurred at a greater depth, between -2.25 and -3.5 m MLLW. Further investigation of the anthropogenic and natural factors causing these differences in distribution is needed.

  17. Quantitative pancreatic β cell MRI using manganese-enhanced Look-Locker imaging and two-site water exchange analysis.

    Science.gov (United States)

    Antkowiak, Patrick F; Vandsburger, Moriel H; Epstein, Frederick H

    2012-06-01

    Pancreatic β-cell imaging would be useful in monitoring the progression of and therapies for diabetes. The purpose of this study was to develop and evaluate quantitative β-cell MRI using manganese (Mn(2+)) labeling of β cells, T1 mapping, and a two-site water exchange model. Normal, pharmacologically-treated, and severely diabetic mice underwent injection of MnCl(2). Pancreatic water proton T1 relaxation was measured using Look-Locker MRI, and two-site water exchange analysis was used to estimate model parameters including the intracellular water proton relaxation rate constant (R1(ic)) and the intracellular fraction as indicators of β-cell function and mass, respectively. Logarithmic plots of T1 relaxation revealed two distinct proton pools relaxing with different T1s, and the two-site water exchange model fit the measured T1 relaxation data better than a monoexponential model. The intracellular R1(ic) time course revealed the kinetics of β-cell Mn(2+) labeling. Pharmacological treatments with nifedipine, tolbutamide, and diazoxide altered R1(ic), indicating that beta cell function was a determinant of Mn(2+) uptake. Intracellular fraction was significantly higher in mice with normal β cell mass than in diabetic mice (14.9% vs. 14.4%, P exchange analysis of T1 relaxation of the Mn(2+)-enhanced pancreas is a promising method for quantifying β cell volume fraction and function. Copyright © 2011 Wiley-Liss, Inc.

  18. Effects of the aromatic substitution pattern in cation-π sandwich complexes.

    Science.gov (United States)

    Wireduaah, Selina; Parker, Trent M; Lewis, Michael

    2013-03-28

    A computational study investigating the effects of the aromatic substitution pattern on the structure and binding energies of cation-π sandwich complexes is reported. The correlation between the binding energies (Ebind) and Hammett substituent constants is approximately the same as what is observed for cation-π half-sandwich complexes. For cation-π sandwich complexes where both aromatics contain substituents the issue of relative conformation is a possible factor in the strength of the binding; however, the work presented here shows the Ebind values are approximately the same regardless of the relative conformation of the two substituted aromatics. Finally, recent computational work has shown conflicting results on whether cation-π sandwich Ebind values (Ebind,S) are approximately equal to twice the respective half-sandwich Ebind values (Ebind,HS), or if cation-π sandwich Ebind,S values are less than double the respective half-sandwich Ebind,HS values. The work presented here shows that for cation-π sandwich complexes involving substituted aromatics the Ebind,S values are less than twice the respective half-sandwich Ebind,HS values, and this is termed nonadditive. The extent to which the cation-π sandwich complexes investigated here are nonadditive is greater for B3LYP calculated values than for MP2 calculated values and for sandwich complexes with electron-donating substituents than those with electron-withdrawing groups.

  19. On the use of a woven mat to control the crack path in composite sandwich structures

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Berggreen, Christian; Carlsson, Leif A.

    2008-01-01

    In the last couple of decades the use of sandwich structures has increased tremendously in applications where low weight is of importance e.g. ship structures, where sandwich panels are often built from fiber reinforced faces and foam cores. An important damage type in sandwich structures......, followed by growth due to continued loading. With debonds present the structure might fail under loads significantly lower than those for an intact sandwich structure [1, 2]. A debond crack in a foam cored sandwich can propagate self similarly or kink away from the interface into either the face or core...... tractionsbetween the separated crack surfaces [4, 5]. The outline of a crack propagating under large scale bridging in a sandwich structure can be seen in Figure 1. The fiber bridging mechanism possesses an increased potential damage tolerance capacity for the sandwich structure if it can be predicatively...

  20. An analytical model of a clamped sandwich beam under low-impulse mass impact

    Directory of Open Access Journals (Sweden)

    Wen-zheng Jiang

    Full Text Available An analytical model is developed to examine a low impulsive projectile impact on a fully clamped sandwich beams by considering the coupled responses of the core and the face sheets. Firstly, based on the dynamic properties of foam cores, the sandwich beam is modeled as two rigid perfectly-plastic beams connected by rigid perfectly-plastic springs. Different from the previous sandwich beam model, the transverse compression and bending effects of the foam core are considered in the whole deformation process. Based on this model, different coupling mechanism of sandwich beams are constructed so that an analytical solution considering small deformation is derived. The coupled dynamic responses of sandwich beams with different core strengths are investigated. The results indicate that this model improves the prediction accuracy of the responses of the sandwich beams, and is available for the situation when the sandwich beam undergoes moderate global deformation.

  1. Radioimmunoassay measurement of urinary ligandin excretion in nephrotoxin-treated rats

    International Nuclear Information System (INIS)

    Bass, N.M.; Kirsch, R.E.; Tuff, S.A.; Campbell, J.A.; Saunders, J.S.

    1979-01-01

    A radioimmunoassay (RIA) was used to establish normal urine excretion of ligandin, a renal tubular protein, in rats, and to study the pattern of ligandin excretion after nephrotoxin administration. Validation of RIA measurement of ligandin in urine is described. A normal range of 2-46 ng/h was obtained for ligandin excretion in rats (n = 24). The time course of ligandin excretion in HgCl 2 and K 2 Cr 2 0 7 treated rats correlated with the histological sequence of damage to the pars recta and pars convoluta of the proximal tubule respectively. Results confirm that renal ligandin is confined mainly to the pars recta of the proximal tubule and small quantities of the protein are present in the pars convoluta. Radioimmunoassay provides a sensitive and specific means for measuring ligandin in urine and is a valuable tool for the detection and study of renal tubular damage. (author)

  2. The application of α1-MG radioimmunoassay in the diagnosis of kidney diseases

    International Nuclear Information System (INIS)

    Liu Guifen; Wang Jianchun; Zhang Qingfeng; Liu Shuying; Han Wensheng; Li Zhihong

    1996-01-01

    A new method for the diagnoses of kidney diseases with α 1 -microglobulin (α 1 -MG) radioimmunoassay is developed. 276 healthy persons' serum and urine are determined by α 1 -MG radioimmunoassay. The result shows that the serum normal number is 54.22 +-22.02 mg/l and the urine 5.57 +- 2.63 mg/l. In contrast, the counterparts of 358 patients with different diseases are also examined. The result shows that there is a remarkable difference between urine α 1 -MG content of patients suffering from such diseases as gestation hypertension, renal insufficiency, nephritis and that of the healthy group (P<0.01). The method provides a stable, sensitive index for the diagnoses of kidney diseases and the examination of kidney function. It can be widely used in the clinical diagnosis

  3. Free light chains of immunoglobulins in normal serum and urine determined by radioimmunoassay

    International Nuclear Information System (INIS)

    Soelling, K.

    1975-01-01

    A radioimmunoassay for determination of free light polypeptide chains from human immunoglobulins in serum and urine is described. The free light chains were isolated from the regular immunoglobulins by gel filtration on Sephadex G-100 columns. In the radioimmunoassay the free and antibody-bound 125 I-labelled light chains were separated by gel filtration through Sephadex G-200 columns. The mean concentration of free light chains in serum from 20 normal subjects was 10.6 mg/l for lambda chains and 13.2 mg/l for kappa chains. The 24-hr urinary excretion was 1.1mg for lambda chains and 3.2 mg for kappa chains. (auth)

  4. 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

  5. Quality characteristics of chemicals for the radioimmunoassay of thyroxine and thyrotropin

    International Nuclear Information System (INIS)

    Verdeja I, C.E.

    1994-01-01

    Radioimmunoassay is a form of saturation analysis in which the test material competes with labelled antigen for a limited amount of antibody, the amount of label displaced being a measure of the antigen in the test sample. In this country, the kits for Radioimmunoassay (RIA) are imported, and this increase the cost of it. Because this lack of production, the National Institute of Nuclear Research (ININ) has developed RIA's kits for the thyroxine (T 4 ), Thyrotropin (TSH) and Triyodotironine (T 3 ) hormones. This work presents the conclusions of the test recommended by the WHO. The quality test were: recuperation, cross reactions, basic parameters, intra and inter assay variations, sensibility and others. The results show that the RIA's kits of the ININ have a good behavior and can be use in the clinical laboratory. (Author)

  6. 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

  7. Radioimmunoassay screening and GC/MS confirmation of whole blood samples for drugs of abuse

    Energy Technology Data Exchange (ETDEWEB)

    Spiehler, V.R.; Sedgwick, P.

    From 1981 to 1984, an average of 300 radioimmunoassay screens on whole blood were performed each week in the authors laboratory. Most samples were screened for opiates phencyclidine and its analogs, barbiturates, and cocaine or its metabolite benzoylecgonine. A commercially available radioimmunoassay was used with modifications to facilitate screening of whole blood. Increasing sample size increased the sensitivity of the assay. Changing reagent concentration (1:1 dilution), incubation time, sample matrix (water, urine, or blood), or fraction counted (precipitate or supernatant) did not affect the utility of the standard curve or the sensitivity of the assay. All positive results for phencyclidine, opiates, cocaine, and related compounds were confirmed by GC/MA. Barbiturate positives were confirmed by UV spectrophotometry.

  8. Increased specificity of plasma glucagon radioimmunoassay by use of acetone extraction

    International Nuclear Information System (INIS)

    Schenck, H. von

    1983-01-01

    The specificity of glucagon determinations by radioimmunoassay with two pancreatic-type glucagon antisera has been determined by means of gel permeation chromatography before and after treatment of human plasma with acetone and ethanol. Acetone precipitates the high molecular mass substances which interfere with the antisera directed against the carboxyl-terminal region of the glucagon molecule and applied in the radioimmunoassay, and which are apparent in the void volume and cross-reacting precursor fragments, while pancreatic glucagon is extracted to slightly more than 50%. Hence acetone treatment is suggested as a suitable means of obtaining specific glucagon results in single samples. Ethanol also precipitates the high molecular mass substances, but partly extracts the precursor fragments in addition to the glucagon. Ethanol treatment is therefore suggested for chemical diagnosis of the glucagonoma syndrome in which the tumor often produces precursor fragments. (Auth.)

  9. 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

  10. The role of carbohydrates in the radioimmunoassay of human low-molecular-mass kininogen

    International Nuclear Information System (INIS)

    Turpeinen, U.; Kaerkkaeinen, T.

    1985-01-01

    The immunoreactivity of human low-molecular-mass kininogen from Cohn plasma fraction IV was investigated after deglycosylations and carbohydrate modifications by radioimmunoassay using the conformation-specific antiserum. Removal of all sialic acids, 44% of amino sugars and 63% of neutral sugars did not alter the immunoreactivity of the protein but the periodate-treated concanavalin A fractions showed strikingly diminished immunoreactivity. A conformational change could account for the observed effect of periodate on the decreased reactivity of the protein in radioimmunoassay. Externally added carbohydrates had no effect on immunoreactivity. The results suggest that the carbohydrate part of kininogen is not involved in the immunoreactivity although it accounts for the observed lectin-binding heterogeneity. (Auth.)

  11. Radioimmunoassay determination of antigenic concordance among hemagglutinins of vaccine and epidemic influenza virus strains

    Energy Technology Data Exchange (ETDEWEB)

    Blokha, V.V.; Yamnikova, S.S.; Karpovich, L.G.; Yakhno, M.A.; Zakstel' skaya, L.Ya.

    Radioimmunoassay studies were conducted on the antigenic concordance of hemagglutinin of influenza A H3N2 viruses, to determine the suitability of vaccine strains in engendering immunity against viruses circulating in nature. Specifically, the inhibition studies involved the hemagglutinins of the A/Victoria/35/72 vaccine strain, the proposed vaccine strain A/Khabarovsk/15/76, and the RK-5 recombinant strains, containing antigenic determinants of viruses isolated in the 1972-1976 epidemic period (A/Victoria/3/75, A/Leningrad/173/75, A/Victoria/112/76). The results showed that A/Victoria/35/72 is becoming less important as a vaccine, but that RK-5 and A/Khabarovsk/15/76 can provide significant immunity with respect to influenza viruses circulating in 1975-1976. These observations point to the usefulness of radioimmunoassay in assessing the suitability of influenza A viruses for vaccine production. 12 references, 2 figures.

  12. Radioimmunoassay of renin-angiotensin-aldosterone in patients with adrenal tumors

    International Nuclear Information System (INIS)

    Slavnov, V.N.; Yakovlev, A.A.; Yugrinov, O.G.; Gandzha, T.I.

    1983-01-01

    The results are presented of a study of the renin-angiotensin-aldosterone system in 89 patients with aldosteronoma, corticosteroma, pheochromocytoma and hypertension. Radioimmunoassay was used to measure aldosterone concentration and renin activity in the peripheral blood and blood from vena cava inferior, the renal and adrenal veins, the circadian cycle of their content and the responsiveness of the glomerular zone of the adrenal cortex and the juxtaglomerular renal system under the influence of lasix intake and the change over from a horizontal into vertical position. Patients with adrenal tumors have shown disorders of renin-angiotensin-aldosterone function. Radioimmunoassay of the renin-angiotensin-aldosterone system promotes early detection of adrenal tumors in the general population of patients with hypertension and can be used for control over therapeutic efficacy

  13. Applications of thin-film sandwich crystallization platforms

    Energy Technology Data Exchange (ETDEWEB)

    Axford, Danny, E-mail: danny.axford@diamond.ac.uk; Aller, Pierre; Sanchez-Weatherby, Juan; Sandy, James [Diamond Light Source, Harwell Oxford, Didcot OX11 0DE (United Kingdom)

    2016-03-24

    Crystallization via sandwiches of thin polymer films is presented and discussed. Examples are shown of protein crystallization in, and data collection from, solutions sandwiched between thin polymer films using vapour-diffusion and batch methods. The crystallization platform is optimal for both visualization and in situ data collection, with the need for traditional harvesting being eliminated. In wells constructed from the thinnest plastic and with a minimum of aqueous liquid, flash-cooling to 100 K is possible without significant ice formation and without any degradation in crystal quality. The approach is simple; it utilizes low-cost consumables but yields high-quality data with minimal sample intervention and, with the very low levels of background X-ray scatter that are observed, is optimal for microcrystals.

  14. Residual Strength Prediction of Debond Damaged Sandwich Panels

    DEFF Research Database (Denmark)

    Berggreen, Carl Christian

    propagation and initiation, as these mechanisms are governing for the overall failure load of the structure. Thus, this presentation will describe the development, validation and application of a FEM based numerical model for prediction of residual strength of damaged sandwich panels. The core......This presentation concerns theoretical and experimental prediction of crack propagation and residual strength of debond damaged sandwich panels. It is evident that in order to achieve highly optimised structures which are able to operate in a stochastic loading environment, damage tolerance...... evaluation based on residual strength prediction is needed. Is a given damage critical for the structural integrity needing immanent repair, or is the damage negligible, where repair can be postponed to the next inspection? These questions are generally interesting for all types of structures...

  15. Sensitivity analysis of sandwich panels with rectangular openings

    Science.gov (United States)

    Chuda-Kowalska, Monika; Malendowski, Michal

    2018-01-01

    Sandwich panels, composed of thin metal sheets and a thick, anisotropic foam core, are considered in the paper. These lightweight structures are frequently weakened by cut-outs and various openings, what is the subject of the present analysis. Due to a complex behavior of such structures, there are no universal, acceptable design rules, that take into account factors related to the kind of modifications that made the panel weaker. In this paper, the problem of the influence of two factors on the mechanical response of sandwich panel is considered, namely: the influence of opening location and type of the load. Additionally, the influence of stiffener, in the form of window frame, is considered. Finally, selected results obtained from FE analyses are compared with the experimental results carried out by the authors and some conclusions are drawn.

  16. 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

  17. Radioimmunoassay for Zearalenone and Zearalanol in Human Serum: Production, Properties, and Use of Porcine Antibodies

    OpenAIRE

    Thouvenot, Daniel; Morfin, Robert F.

    1983-01-01

    To produce antigens susceptible to raise antibodies for resorcylic acid lactones, the 6′-carboxymethyloxime derivatives of zearalenone and zearalanone were bound to bovine serum albumin. Pigs could be immunized by using these antigens, the best titer in antibodies being obtained with the zearalenone antigen. The porcine antibodies were specific for the resorcylic acid lactones of structural resemblance with zearalenone. This specificity made the antibodies usable for a radioimmunoassay of zea...

  18. Interferences in radioimmunoassay of aflatoxins in food and fodder samples of plant origin

    Energy Technology Data Exchange (ETDEWEB)

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

    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 ..mu..g aflatoxin B/sub 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.

  19. Radioimmunoassay of ferritin, CEA and prolactin for assessment of prognosis and efficacy of breast cancer therapy

    International Nuclear Information System (INIS)

    Sklyar, S.Yu.; Chebotareva, Eh.D.; Ganul, V.L.; Korolev, V.I.

    1987-01-01

    The levels of tumor markers - CEA, deritin and prolactin (the hormone of the anterior pituitary gland) were studied in the blood serum of 178 breast cancer patients in the menopause during combined therapy using a radioimmunoassay. This combination was shown to be informative for assessment of prognosis of disease and efficacy of antitumor therapy which was confirmed by clinical and x-ray findings and observation of a tumor process in breast cancer patients over a 5-year period

  20. 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

  1. The insulin radioimmunoassay kit prepared by IPEN-CNEN/SP - Brazil

    International Nuclear Information System (INIS)

    Mesquita, C.H. de; Silva, C.P.G. da; Hamada, M.M.

    1985-11-01

    The specification and methodological aspects of the insulin radioimmunoassay kit produced by IPEN-CNEN/SP - Brazil are described. The limitations taking care and the following quality control parameters or procedures are discussed: specific radioactivity, comparison between two insulin - 125 I purification procedures, affinity constant 'K' of the antigen - antibody reaction, minimal detectable dose (MDD), kinetics degradation of the radioinsulin, radioassay imprecision profile, radioassay performance temperature dependence and normal values histogram. (Author) [pt

  2. Preparation of iodine - 125 - labeled insulin for radioimmunoassay: comparison of chloramine T and iodogen iodination

    International Nuclear Information System (INIS)

    Toledo e Souza, I.T. de; Giannella Neto, D.; Wajchenberg, B.L.

    1988-05-01

    Stoichiometric iodination of porcine insulin was performed to the general method of Hunter and Greenwood with modifications recommended by Roth. These method was compared with radioidination using Iodogen. Films of Iodogen react rapidly in the solid phase with aqueous mixtures of I - and proteins. For two methods satisfactory activity of the labeled porcine insulin was obtained and characteristics of the radioimmunoassay were studied. (author) [pt

  3. Use of a rapid hCG-beta-subunit radioimmunoassay in acute gynaecological emergencies

    International Nuclear Information System (INIS)

    Seppala, M.; Tontti, K.; Ranta, T.; Stenman, U.-H.; Chard, T.

    1980-01-01

    Chorionic gonadotrophin (hCG) was measured by a rapid and sensitive radioimmunoassay in 100 female patients with lower abdominal pain attending an emergency department. Of the 24 subjects with a positive result, 22 had evidence of pregnancy (ectopic or uterine). Of the 76 patients with negative results, 3 had some evidence of pregnancy. This test may be of considerable practical value in the differential diagnosis of acute abdominal emergencies in women of reproductive age. (author)

  4. 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

  5. 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

  6. Three magnetic particles solid phase radioimmunoassay for T4: Comparison of their results with established methods

    International Nuclear Information System (INIS)

    Bashir, T.

    1996-01-01

    The introduction of solid phase separation techniques is an important improvement in radioimmunoassays and immunoradiometric assays. Magnetic particle solid phase method has additional advantages over others, as the separation is rapid and centrifugation is not required. Three types of magnetic particles have been studied in T 4 RIA and the results have been compared with commercial kits and other established methods. (author). 4 refs, 9 figs, 2 tabs

  7. Standardization of the method for measurement of plasma estrone by radioimmunoassay

    International Nuclear Information System (INIS)

    Vilanova, M.S.V.; Moreira, A.C.; Sala, M.M. de; Sa, M.F.S. de

    1994-01-01

    The present paper has as objective standardize a radioimmunoassay method for measurement of plasma estrone. Ethyl ether was used for plasma extraction. The sensitivity (Minimal detectable dose) was 3,7 pg/tube; the reproducibility (inter assay error) was 8,6%; the precision (intra assay error) was 4,1%. As a biological control the plasma estrone was ml) and in 24 patients with polycystic ovarian syndrome (median = 77,9 pg/ml). (author). 6 refs, 2 figs, 2 tabs

  8. 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)

  9. 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

  10. 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)

  11. An improved radioimmunoassay method for the detection of IgG antibodies against cytomegalovirus

    International Nuclear Information System (INIS)

    Berry, N.J.; Grundy, J.E.; Griffiths, P.D.

    1986-01-01

    The non-specific binding seen with human sera in a radioimmunoassay for the detection of IgG antibodies specific for CMV can be reduced greatly by using a murine monoclonal antibody as a radiolabelled detecting antibody. Such non-specific binding formerly obtained with a polyclonal detecting antibody was due to the binding of the polyclonal reagent to factors on the solid phase other than IgG molecules. (Auth.)

  12. 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

  13. 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

  14. Crystallization in sandwich nanocomposites of PE, PP and POM polymers

    Czech Academy of Sciences Publication Activity Database

    Šlouf, Miroslav; Vacková, Taťana; Vu, Ngoc Húng; Sikora, Antonín; Kratochvíl, Jaroslav; Šandová, Hana; Steinhart, Miloš

    2012-01-01

    Roč. 19, č. 2 (2012), s. 107 ISSN 1211-5894. [Struktura 2012. Kolokvium Krystalografické společnosti. 11.06.2012-14.06.2012, Klatovy] R&D Projects: GA ČR GAP205/10/0348 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : sandwich nanocomposites * nanoparticles * titanium nanotubes Subject RIV: CF - Physical ; Theoretical Chemistry

  15. Non-linear analytical solutions for laterally loaded sandwich plates

    DEFF Research Database (Denmark)

    Riber, Hans Jørgen

    1997-01-01

    . The results of the analytical calculations are discussed and compared with numerical non-linear finite difference calculations and large-deflection experiments of equivalent plates. The presented methods lead to good results for plate response and provide the engineer with an alternative method for the design...... of sandwich plates subjected to high lateral loading. (C) 1997 Published by Elsevier Science Ltd. All rights reserved....

  16. Outcome of the TURP-TUVP sandwich procedure for minimally ...

    African Journals Online (AJOL)

    shanker

    TURP–TUVP sandwich procedure for the surgical treatment of BPH larger than 40cc in volume. 23 used was 21.5 L (SD = 4.9).The mean post-operative hospital stay was 3.5 days (range 3- 4 days). Overall,. 11 (19%) patients had blood transfusion, there was no incidence of TUR syndrome and one mortality was recorded ...

  17. Composite Sandwich Structures for Shock Mitigation and Energy Absorption

    Science.gov (United States)

    2016-06-28

    shells. • Validate analytical solutions with finite element analysis using ABAQUS and test data , if available. TECHNICAL APPROACH Composite sandwich...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources...gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any

  18. Comparison of double-antibody radioimmunoassay with Farr-technique radioimmunoassay and double-antibody enzyme immunoassay for α-fetoprotein

    International Nuclear Information System (INIS)

    Kirkpatrick, A.; Wepsic, H.T.; Nakamura, R.M.

    1977-01-01

    We describe double-antibody procedures for determining α-fetoprotein in human serum. An equilibrium procedure can be done in 24 h with a sensitivity of at least 4 μg/liter and coefficient of variation of 5.5%. There are no interferences from normal human sera or sera with certain commonly seen chemical abnormalities. We also describe and discuss sequential procedures that range in sensitivity from 250 ng to 1 μg/liter and require 24 to 48 h incubation. The precise (mid-range) portion of the dose/response curve for sequential procedures can be shifted to higher or lower values by an adjustment of the time of preliminary incubation of antibody with unlabeled antigen. With a 37 0 C incubation, a sequential procedure can be completed in 7 h. Sensitivity is 1 μg/liter, and coefficient of variation 8.0%. The relative merits of the above assay procedures are discussed. The double-antibody radioimmunoassay is twice as sensitive as the Farr procedure and it is free of the large and variable nonspecific precipitation that accompanies the precipitation of bound antigen with sodium sulfate solution. Double-antibody radioimmunoassay is superior to enzyme immunoassay in both sensitivity and precision

  19. Influence of various desinfectants on the radioimmuno-assay for Australia antigen

    International Nuclear Information System (INIS)

    Bernhard, U.

    1979-01-01

    At normal room temperature dilution series were produced out of pooled serum, serum previously treated with UV irradiation and beta propiolacton, and serum of patients with hepatitis type B and various desinfectants. After differing incubation times the Australia antigen titre was measured in the radioimmunoassay. Electronmicroscopic examinations should detect possible morphologic changes of the Dane particles. The counts/min. measured for Australia antigen after an incubation with aldehyde-containing preparations, are below the limit value with serum treated previously with UV light and beta propiolacton; in negative Australia-antigen-positive serum the counts/min. are close to the limit value. The antigenity is clearly reduced. The comparison with an insulin containing serum showed that also the radioimmunoassay was influenced by the aldehyde. A direct influence of the aldehydes on the protein seems to be possible. From this results that the radioimmunoassay for Australia antigen cannot be used as the exclusive method for measuring the efficacy of desinfectants compared to Dane particles. The morphologic changes of the Dane particles observed in the electronic microscope confirm the supposition that the desinfectants influence the hepatitis viruses. (orig./MG) [de

  20. 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

  1. Creatine kinase radioimmunoassay and isoenzyme electrophoresis compared in the diagnosis of acute myocardial infarction

    International Nuclear Information System (INIS)

    Homburger, H.A.; Jacob, G.L.

    1980-01-01

    We compared, in 116 patients, the relative usefulness of results of tests for creatine kinase B-isoenzymes, as measured by radioimmunoassay, and the MB isoenzyme, as measured by electrophoresis, in diagnosis of acute myocardial infarction. The radioimmunoassay was specific for isoenzymes of creatine kinase containing the B subunit. All patients with acute transmural infarcts had positive test results by both techniques, but concentrations of B-isoenzymes were more frequently above normal than were MB bands in the case of patients with acute subendocardial infarcts and in the case of all patients with acute myocardial infarcts from whom sera were collected more than 24 h after onset of chest pain. Concentrations of B-isoenzymes also were increased, even when MB bands were not electrophoretically detectable in specimens from several patients without documented acute myocardial infarcts. These abnormal results presumably were caused by increased concentrations of the BB isoenzyme in serum. Accordingly, an increased concentration of B-isoenzymes had less diagnostic specificity and predictive value for acute myocardial infarction than did a detectable MB band. Results of isoenzyme electrophoresis were more reliable for establishing this diagnosis, but the results of radioimmunoassay were more reliable for excluding it in patients with chest pain as the primary symptom

  2. Development and characterization of a radioimmunoassay to measure human tissue kallikrein in biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Bagshaw, A.F.; Whicher, J.T. (Bristol Royal Infirmary (UK)); Bhoola, K.D.; Lemon, M.J.C. (Bristol Univ. (UK). Medical School)

    1984-05-01

    A direct radioimmunoassay has been developed to measure tissue kallikrein in human biological fluids, including serum, plasma, urine, pancreatic juice and saliva. Purified kallikreins from human urine and human saliva were used to raise rabbit antibody and each labelled with Na/sup 125/I for use in the radioimmunoassay. Comparison of the different antigen-antibody systems was then made. Bound and free enzyme were separated by a double-antibody technique. The usable range of the standard curve was from 2.5 to 100 ..mu..g kallikrein/1. The intra-assay coefficient of variation was 4.7%, the interassay coefficient of variation 8.9% and the recoveries of purified kallikrein added to the samples were 99.3, 96.0, 110.8 and 81.2% for urine, saliva, serum and plasma respectively. Parallel dilution curves were obtained for serum and plasma, as well as urine, saliva and pancreatic juice. Plasma anticoagulated with EDTA or heparin gave consistently lower values than serum, when measured in the radioimmunoassay. From eight different subjects plasma (EDTA) values were on average 50% lower than those of serum, and subsequent experiments revealed that treatment of blood with some anticoagulants, in particular heparin and EDTA, resulted in a marked reduction in measurable tissue kallikrein.

  3. Sandwich Structured Composites for Aeronautics: Methods of Manufacturing Affecting Some Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Aneta Krzyżak

    2016-01-01

    Full Text Available Sandwich panels are composites which consist of two thin laminate outer skins and lightweight (e.g., honeycomb thick core structure. Owing to the core structure, such composites are distinguished by stiffness. Despite the thickness of the core, sandwich composites are light and have a relatively high flexural strength. These composites have a spatial structure, which affects good thermal insulator properties. Sandwich panels are used in aeronautics, road vehicles, ships, and civil engineering. The mechanical properties of these composites are directly dependent on the properties of sandwich components and method of manufacturing. The paper presents some aspects of technology and its influence on mechanical properties of sandwich structure polymer composites. The sandwiches described in the paper were made by three different methods: hand lay-up, press method, and autoclave use. The samples of sandwiches were tested for failure caused by impact load. Sandwiches prepared in the same way were used for structural analysis of adhesive layer between panels and core. The results of research showed that the method of manufacturing, more precisely the pressure while forming sandwich panels, influences some mechanical properties of sandwich structured polymer composites such as flexural strength, impact strength, and compressive strength.

  4. Sandwich-like Microenvironments to Harness Cell/Material Interactions

    Science.gov (United States)

    Ballester-Beltrán, José; Lebourg, Myriam; Salmerón-Sánchez, Manuel

    2015-01-01

    Cell culture has been traditionally carried out on bi-dimensional (2D) substrates where cells adhere using ventral receptors to the biomaterial surface. However in vivo, most of the cells are completely surrounded by the extracellular matrix (ECM), resulting in a three-dimensional (3D) distribution of receptors. This may trigger differences in the outside-in signaling pathways and thus in cell behavior. This article shows that stimulating the dorsal receptors of cells already adhered to a 2D substrate by overlaying a film of a new material (a sandwich-like culture) triggers important changes with respect to standard 2D cultures. Furthermore, the simultaneous excitation of ventral and dorsal receptors shifts cell behavior closer to that found in 3D environments. Additionally, due to the nature of the system, a sandwich-like culture is a versatile tool that allows the study of different parameters in cell/material interactions, e.g., topography, stiffness and different protein coatings at both the ventral and dorsal sides. Finally, since sandwich-like cultures are based on 2D substrates, several analysis procedures already developed for standard 2D cultures can be used normally, overcoming more complex procedures needed for 3D systems. PMID:26274867

  5. Hypervelocity Impact Evaluation of Metal Foam Core Sandwich Structures

    Science.gov (United States)

    Yasensky, John; Christiansen, Eric L.

    2007-01-01

    A series of hypervelocity impact (HVI) tests were conducted by the NASA Johnson Space Center (JSC) Hypervelocity Impact Technology Facility (HITF) [1], building 267 (Houston, Texas) between January 2003 and December 2005 to test the HVI performance of metal foams, as compared to the metal honeycomb panels currently in service. The HITF testing was conducted at the NASA JSC White Sands Testing Facility (WSTF) at Las Cruces, New Mexico. Eric L. Christiansen, Ph.D., and NASA Lead for Micro-Meteoroid Orbital Debris (MMOD) Protection requested these hypervelocity impact tests as part of shielding research conducted for the JSC Center Director Discretionary Fund (CDDF) project. The structure tested is a metal foam sandwich structure; a metal foam core between two metal facesheets. Aluminum and Titanium metals were tested for foam sandwich and honeycomb sandwich structures. Aluminum honeycomb core material is currently used in Orbiter Vehicle (OV) radiator panels and in other places in space structures. It has many desirable characteristics and performs well by many measures, especially when normalized by density. Aluminum honeycomb does not perform well in Hypervelocity Impact (HVI) Testing. This is a concern, as honeycomb panels are often exposed to space environments, and take on the role of Micrometeoroid / Orbital Debris (MMOD) shielding. Therefore, information on possible replacement core materials which perform adequately in all necessary functions of the material would be useful. In this report, HVI data is gathered for these two core materials in certain configurations and compared to gain understanding of the metal foam HVI performance.

  6. Microtomography with a sandwich detector for mouse bone imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Kim, Junwoo; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of); Youn, Hanbean; Jeon, Hosang [Pusan National University Yangsan Hospital, Yangsan (Korea, Republic of)

    2015-10-15

    Single-shot dual-energy imaging, using sandwich detector, the rear detector usually uses a thicker x-ray converter to enhance quantum efficiency with the higher-energy spectrum, hence providing a blurrier image than the front detector. The weighted logarithmic subtraction of the two images therefore results in a form of unsharp masking that enhances edges in the resultant image. Inspired by this observation, we have developed a micro computed tomography (micro-CT) system with the sandwich detector for high-resolution bone imaging of small animals. The sandwich detector consists of two flat-panel detectors by stacking one upon the other. Although the x-ray beam continuously irradiates, the step-rotation of an object and stay-readout of projection data were considered for the scanning and data gathering. It will be necessary that more elaborate experiments with the mouse and/or other quantitative phantoms. And quantification of the image quality of bone-enhanced images in comparisons with the conventional images will be performed. The image analysis of differences between bone-enhanced images obtained from the projection- and image-based approaches can be performed.

  7. Impact properties of aluminium - glass fiber reinforced plastics sandwich panels

    Directory of Open Access Journals (Sweden)

    Mathivanan Periasamy

    2012-06-01

    Full Text Available Aluminium - glass fiber reinforced plastics (GFRP sandwich panels are hybrid laminates consisting of GFRP bonded with thin aluminum sheets on either side. Such sandwich materials are increasingly used in airplane and automobile structures. Laminates with varying aluminium thickness fractions, fiber volume fractions and orientation in the layers of GFRP were fabricated by hand lay up method and evaluated for their impact performance by conducting drop weight tests under low velocity impacts. The impact energy required for initiating a crack in the outer aluminium layer as well as the energy required for perforation was recorded. The impact load-time history was also recorded to understand the failure behavior. The damage depth and the damage area were measured to evaluate the impact resistance. Optical photography and scanning electron micrographs were taken to visualize the crack and the damage zone. The bidirectional cross-ply hybrid laminate (CPHL has been found to exhibit better impact performance and damage resistance than the unidirectional hybrid laminate (UDHL. Increase in aluminium thickness fraction (Al tf and fiber volume fraction (Vf resulted in an increase in the impact energy required for cracking and perforation. On an overall basis, the sandwich panels exhibited better impact performance than the monolithic aluminium.

  8. Structural performance of metallic sandwich beams with hollow truss cores

    International Nuclear Information System (INIS)

    Rathbun, H.J.; Zok, F.W.; Waltner, S.A.; Mercer, C.; Evans, A.G.; Queheillalt, D.T.; Wadley, H.N.G.

    2006-01-01

    The article focuses on the structural performance of sandwich beams with hollow truss lattice cores made from a ductile stainless steel. The trusses are arranged in an orthogonal (cross-ply) configuration, in either ±45 o (diamond) or 0 o /90 o (square) orientations with respect to the face sheets. The responses in shear, tension and compression, as well as simply supported and fully clamped bending, are measured for specimens with both core orientations. While the two cores perform equally well in compression, the diamond orientation exhibits higher shear strength but lower stretch resistance. For bend-dominated loadings of the sandwich beams, the core in the diamond orientation is preferred because of its higher shear strength. For stretch-dominated loadings encountered in large-displacement, fully clamped bending, the square orientation is superior. Models of core and beam yielding are used to rationalize these observations. Optimizations are then performed to identify strong lightweight designs and to enable performance comparisons with other sandwich structures

  9. Sandwich-structured hollow fiber membranes for osmotic power generation

    KAUST Repository

    Fu, Feng Jiang

    2015-11-01

    In this work, a novel sandwich-structured hollow fiber membrane has been developed via a specially designed spinneret and optimized spinning conditions. With this specially designed spinneret, the outer layer, which is the most crucial part of the sandwich-structured membrane, is maintained the same as the traditional dual-layer membrane. The inner substrate layer is separated into two layers: (1) an ultra-thin middle layer comprising a high molecular weight polyvinylpyrrolidone (PVP) additive to enhance integration with the outer polybenzimidazole (PBI) selective layer, and (2) an inner-layer to provide strong mechanical strength for the membrane. Experimental results show that a high water permeability and good mechanical strength could be achieved without the expensive post treatment process to remove PVP which was necessary for the dual-layer pressure retarded osmosis (PRO) membranes. By optimizing the composition, the membrane shows a maximum power density of 6.23W/m2 at a hydraulic pressure of 22.0bar when 1M NaCl and 10mM NaCl are used as the draw and feed solutions, respectively. To our best knowledge, this is the best phase inversion hollow fiber membrane with an outer selective PBI layer for osmotic power generation. In addition, this is the first work that shows how to fabricate sandwich-structured hollow fiber membranes for various applications. © 2015 Elsevier B.V.

  10. Use of inorganic salts to minimize serum interference in a sandwich enzyme immunoassay for human growth hormone using Fab'-horseradish peroxidase conjugate.

    Science.gov (United States)

    Hashida, S; Nakagawa, K; Imagawa, M; Inoue, S; Yoshitake, S; Ishikawa, E; Endo, Y; Ohtaki, S; Ichioka, Y; Nakajima, K

    1983-12-30

    In a sandwich enzyme immunoassay (EIA) for human growth hormone (hGH) with anti-hGH Fab'-peroxidase conjugate, the effects of inorganic salts on serum interference were examined, and serum interference was eliminated by incubation of serum samples with anti-hGH IgG-coated polystyrene balls in the presence of 0.4 mol/l NaCl, avoiding the need for hGH-free serum. The sensitivity for hGH was 60 fg/tube or 3 ng/l of serum. No cross-reaction was observed with prolactin, chorionic gonadotropin or luteinizing, thyroid-stimulating and follicle-stimulating hormones. The coefficients of within-assay and between-assay variations were 2.8-6.5% and 4.8-8.7%, respectively. The regression equation and correlation coefficient to radioimmunoassay (RIA) were y(EIA) = 0.89x(RIA) + 0.11 and 0.98 (n = 100), respectively. hGH levels in normal male and female adult serum taken between 9:00 and 10:00 a.m. after overnight fasting and 1 h rest were 312 ng/l (range 53-940 ng/l; n = 10) and 662 ng/l (112-2195 ng/l; n = 13), respectively.

  11. Three-dimensional vibration analysis of functionally graded material sandwich plates

    Science.gov (United States)

    Li, Q.; Iu, V. P.; Kou, K. P.

    2008-03-01

    Free vibration of functionally graded material sandwich rectangular plates with simply supported and clamped edges is studied based on the three-dimensional linear theory of elasticity. Two common types of FGM sandwich plates, namely, the sandwich with FGM facesheet and homogeneous core and the sandwich with homogeneous facesheet and FGM core, are considered. The three displacements of the plates are expanded by a series of Chebyshev polynomials multiplied by appropriate functions to satisfy the essential boundary conditions. The natural frequencies are obtained by Ritz method. Rapid convergence is observed in this study. The natural frequencies of simply supported power-law FGM sandwich plates are compared with results from different two-dimensional plate theories. Parametric study is performed for varying volume fraction, layer thickness ratios, thickness-length ratios and aspect ratios of the sandwich plates.

  12. Guidelines for analysis, testing, and nondestructive inspection of impact-damaged composite sandwich structures

    National Research Council Canada - National Science Library

    Shyprykevich, Peter

    2003-01-01

    Sandwich construction composites are used in a wide variety of structural applications largely because of their relative advantages over other designs in terms of improved stability, weight savings...

  13. Interfacial Crack Arrest in Sandwich Panels with Embedded Crack Stoppers Subjected to Fatigue Loading

    DEFF Research Database (Denmark)

    Martakos, G.; Andreasen, J. H.; Berggreen, Christian

    2017-01-01

    A novel crack arresting device has been implemented in sandwich panels and tested using a special rig to apply out-of-plane loading on the sandwich panel face-sheets. Fatigue crack propagation was induced in the face-core interface of the sandwich panels which met the crack arrester. The effect...... of the embedded crack arresters was evaluated in terms of the achieved enhancement of the damage tolerance of the tested sandwich panels. A finite element (FE) model of the experimental setup was used for predicting propagation rates and direction of the crack growth. The FE simulation was based on the adoption...... as the overall performance of the crack arresters....

  14. Mechanical evaluation with fe analysis of sandwich panels for wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Yasaswi, M.; Naveen, P.N.E.; Prasad, R.V. [GIET. Dept. of Mechanical Engineering, Rajahmundry (India)

    2012-07-01

    Sandwich panels are notable for their structural efficiency and are used as load bearing components in various branches of engineering, especially in aerospace and marine industries. The objective of the present work is to perform computer-aided analysis on sandwich panels. The analysis of sandwich panel with truss core are compared with other four types of sandwich panel with continuous corrugated core, top hat core, zed core and channel core. The basic reason to use sandwich structure is to save weight, however smooth skins and excellent fatigue resistance are also attributes of a sandwich structure. A sandwich is comprised of two layered composite materials formed by bonding two or more thin facings or face sheets to relatively thick core materials. In this type of construction the facings resist nearly all of the in-plane loads and out-of-plane bending moments. The thin facings provide nearly all of the bending stiffness because they are generally of a much higher modulus material is located at a greatest distance from the neutral axis of the component. The basic concept of sandwich panel is that the facings carry the bending loads and the core carries the shear loads. The main function of the core material is to distribute local loads and stresses over large areas. From all this analysis it is concluded that the truss core Sandwich panels can be used in wind turbine blade design. (Author)

  15. Comparison of an enzyme-immunoassay with a radio-immunoassay ...

    African Journals Online (AJOL)

    1990-07-21

    Jul 21, 1990 ... The anti-HBs test uses a 'sandwich' method in which the patient's serum is added to beads coated with HBsAg and, after a period of incubation, HBsAg conjugated with iodine-. 125 which binds to any anti-HBs on the bead, is added. Department of Virology, University of the Witwatersrand and National ...

  16. A dual-monoclonal sandwich ELISA specific for hepcidin-25.

    Science.gov (United States)

    Butterfield, Anthony M; Luan, Peng; Witcher, Derrick R; Manetta, Joseph; Murphy, Anthony T; Wroblewski, Victor J; Konrad, Robert J

    2010-11-01

    Hepcidin, a key regulator of iron metabolism, binds to the iron transporter ferroportin to cause its degradation. In humans, hepcidin deficiency has been linked to hemochromatosis and iron overload, whereas increased concentrations have been reported in anemia of cancer and chronic disease. There is currently an unmet clinical need for a specific immunoassay with a low limit of quantification to measure serum concentrations of hepcidin-25, the active form of the protein. We generated 2 antihepcidin-25 monoclonal antibodies and used them to build a sandwich ELISA. We correlated ELISA results to hepcidin-25 measurements by LC-MS and used ELISA to measure serum hepcidin-25 concentrations in normal individuals, cancer patients, and patients with rheumatoid arthritis. The sandwich ELISA was highly specific for hepcidin-25, having a limit of quantification of 0.01 μg/L (10 pg/mL). Serum concentrations of hepcidin-25 measured by ELISA correlated with hepcidin-25 concentrations measured by using an independent LC-MS assay (r = 0.98, P < 0.001). Hepcidin-25 concentrations were increased in patients with cancer (median 54.8 μg/L, 25%-75% range 23.2-93.5 μg/L, n = 34) and rheumatoid arthritis (median 10.6 μg/L, 25%-75% range 5.9-18.4 μg/L, n = 76) compared with healthy individuals (median 1.20 μg/L, 25%-75% range 0.42-3.07 μg/L, n = 100). The use of 2 monoclonal antibodies in a sandwich ELISA format provides a robust and convenient method for measuring concentrations of the active form of hepcidin. This ELISA should help to improve our understanding of the role of hepcidin in regulating iron metabolism.

  17. Buckling analysis of laminated sandwich beam with soft core

    Directory of Open Access Journals (Sweden)

    Anupam Chakrabarti

    Full Text Available Stability analysis of laminated soft core sandwich beam has been studied by a C0 FE model developed by the authors based on higher order zigzag theory (HOZT. The in-plane displacement variation is considered to be cubic for the face sheets and the core, while transverse displacement is quadratic within the core and constant in the faces beyond the core. The proposed model satisfies the condition of stress continuity at the layer interfaces and the zero stress condition at the top and bottom of the beam for transverse shear. Numerical examples are presented to illustrate the accuracy of the present model.

  18. Standard Test Method for Shear Fatigue of Sandwich Core Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers determination of the effect of repeated shear loads on sandwich core materials. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  19. Standard Test Method for Dimensional Stability of Sandwich Core Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This test method covers the determination of the sandwich core dimensional stability in the two plan dimensions. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  20. FINITE ELEMENT MODELING OF THIN CIRCULAR SANDWICH PLATES DEFLECTION

    Directory of Open Access Journals (Sweden)

    K. S. Kurachka

    2014-01-01

    Full Text Available A mathematical model of a thin circular sandwich plate being under the vertical load is proposed. The model employs the finite element method and takes advantage of an axisymmetric finite element that leads to the small dimension of the resulting stiffness matrix and sufficient accuracy for practical calculations. The analytical expressions for computing local stiffness matrices are found, which can significantly speed up the process of forming the global stiffness matrix and increase the accuracy of calculations. A software is under development and verification. The discrepancy between the results of the mathematical model and those of analytical formulas for homogeneous thin circularsandwich plates does not exceed 7%.

  1. 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

  2. Radioimmunoassay for human myoglobin: methods and results in patients with skeletal muscle or myocardial disorders

    International Nuclear Information System (INIS)

    Miyoshi, K.; Saito, S.; Kawai, H.; Kondo, A.; Iwasa, M.; Hayashi, T.; Yagita, M.

    1978-01-01

    A sensitive and specific radioimmunoassay has been developed for the measurement of serum Mb. Immunization of rabbit with human Mb yielded anti-Mb antibody which was purified by affinity chromatography. Human hemoglobin, CK, and the component of serum per se did not appear to cross-react with the antibody. Mb was radiolabeled by the chloramine T method. The radioimmunoassay method could detect as little as 0.3 ng of Mb and was not affected by hemolysis. Information is also given on precision, recovery, and specimen preservation. Mb levels could be detected in all of 120 normal adults, and the values ranged between 1 and 28 ng/ml (mean, 13.1 +- 6.1). No sex difference was observed. Levels were markedly elevated in all the patients with progressive muscular dystrophy, especially in the Duchenne type at the level of 40 to 1700 ng/ml. It was also noticed that about 70% of female gene carriers of Duchenne type had a slightly increased Mb level. An elevated serum Mb was also noted in polymyositis. In every case of acute myocardial infarction, serum Mb levels were increased, peak values ranging from 175 to 4400 ng/ml and averaging 1162 +- 287.9 Mb levels were elevated faster and peaked earlier (within 6 to 12 hr after the attack) than serum CK activity and returned to nearly normal range within 3 to 4 days. The increase in serum Mb was also noticed in shock and surgery. These data indicate that radioimmunoassay of Mb is a useful test for judging the myolytic state of myogenic myopathies and for early detection of myocardial infarction

  3. Radioimmunoassay and chromatographic similarity of circulating endogenous gonadotropin releasing hormone and hypothalamic extracts in man. [/sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Mortimer, C.H. (St. Bartholomew' s Hospital, London); McNeilly, A.S.; Rees, L.H.; Lowry, P.J.; Gilmore, D.; Dobbie, H.G.

    1976-10-01

    A highly sensitive radioimmunoassay for the gonadotropin releasing hormone has been developed in order to study its physiological importance in man. In view of the expected low concentrations in peripheral blood, large volumes of human plasma were extracted by two different methods and the characteristics of the radioimmunoassayable material compared with those of synthetic decapeptide and extracts of human hypothalami. The results indicate that radioimmunoassayable gonadotropin releasing hormone is present in some human plasmas but the plasma concentrations are less than 2.5 pg/ml. Peripheral levels were more consistently measurable in women at midcycle and after the menopause. The hormone was undetectable in the plasma of normal men, human cerebrospinal fluid, and fetal cerebral tissue, but was present in fetal hypothalami.

  4. A radioimmunoassay method for the rapid detection of Candida antibodies is experimental systematic candidiasis

    International Nuclear Information System (INIS)

    Huang, Y.; Berry, W.; Cooper, H.; Zachariah, Y.; Newman, T.

    1979-01-01

    Rabbits were employed as experimental models to evaluate a solid-phase radioimmunoassay (RIA) method for the diagnosis of systematic candidiasis. Ten rabbits were incubated subcutaneously to mimic superficial candidiasis and were found to produce no antibodies to Candida as determined by both immunodiffusion and RIA procedures. However, 94 per cent of 18 rabbits systematically infected by intravenous injection of Candida cells were observed to produce antibody as assessed by the RIA technique. These data encourage further tests with human sera and the continued development of this RIA procedure as a useful tool in the early serodiagnosis of systematic candidiasis. (Auth.)

  5. Direct radioimmunoassay for the detection of barbiturates in blood and urine

    International Nuclear Information System (INIS)

    Mason, P.A.; Law, B.; Pocock, K.; Moffat, A.C.

    1982-01-01

    A radioimmunoassay has been developed for the detection of barbiturates in blood and urine without any pre-treatment of the sample. It is based on a radioiodinated derivative of 4-hydroxyphenobarbitone which allows use of relatively simple gamma-counting procedures. The assay can detect therapeutic levels of barbiturates in very small amounts (50 μl) of blood and urine samples. It is cheap, rapid, simple to perform and is broadly specific for the barbiturate class of drugs to the exclusion of related drugs. The assay is, therefore, very well suited to the task of screening large numbers of samples for the presence of barbiturates. (author)

  6. Numerical proceessing of radioimmunoassay results using logit-log transformation method

    International Nuclear Information System (INIS)

    Textoris, R.

    1983-01-01

    The mathematical model and algorithm are described of the numerical processing of the results of a radioimmunoassay by the logit-log transformation method and by linear regression with weight factors. The limiting value of the curve for zero concentration is optimized with regard to the residual sum by the iterative method by multiple repeats of the linear regression. Typical examples are presented of the approximation of calibration curves. The method proved suitable for all hitherto used RIA sets and is well suited for small computers with internal memory of min. 8 Kbyte. (author)

  7. 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)

  8. A rapid solid-phase radioimmunoassay for human plasma follicle-stimulating hormone

    International Nuclear Information System (INIS)

    Lovesey, A.C.

    1980-01-01

    The measurement of plasma levels of human follicle-stimulating hormone (FSH) has proved to be of value for the study of the hypothalamic-hypophyseal-gonadal axis, greatly facilitating the diagnosis and management of problems relating to the menopause and infertility. A solid-phase radioimmunoassay for human FSH has been developed. This system is characterised by high precision, is economical, and is considerably faster to operate than conventional double antibody systems used in the hospital assay service. Reference values for plasma FSH in various endocrine states are recorded and discussed. (author)

  9. A radioimmunoassay for antibodies against surface membrane antigens using adhering cells

    International Nuclear Information System (INIS)

    Tax, A.; Manson, L.A.

    1976-01-01

    A radioimmunoassay using cells adhering to plastic is described. In this assay, A-10 mammary carcinoma attached to the surface of plastic in microtiter plates were permitted to bind antibody and the bound antibody was detected with purified rabbit 125 I-antimouse-Fab. The bound radioactive material was eluted with glycine-HCl buffer (pH 2.5), and the acid eluates were counted in a gamma counter. This assay can be used to detect cytolic or noncytolic antibody to cell surface antigens in studies with any tumor or normal cell that will adhere to a solid surface

  10. 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

  11. 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

  12. Radioimmunoassay of class-specific antibodies to Streptococcus mutans in monkey serum and saliva

    International Nuclear Information System (INIS)

    Walker, J.; Colman, G.; Huges, M.

    1979-01-01

    A radioimmunoassay (RIA) has been developed to measure class-specific antibodies to Streptococcus mutans in the serum and saliva of monkeys (Macaca fascicularis). Antihuman immunoglobulin antibodies purified by affinity chromatography on immobilised monkey immoglobulins and labelled with 125 I were employed. Formalised cells of S. mutans and an extract of culture supernatant adsorbed to polystyrene wells were used as solid-phase antigens. The coefficients of variation of IgG, IgA, and IgM assays were less than or equal to 10% for both antigen systems. It is shown that this RIA is a sensitive, reproducible and quantitative method. (Auth.)

  13. 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

  14. Diagnosis application of ACTH radioimmunoassay in diseases of hypothalamus, hypophysis and adrenal axis

    International Nuclear Information System (INIS)

    Moreira, A.C.; Foss, M.C.; Iazigi, N.

    1988-01-01

    The diagnostic value of 900-1,100 am plasma ACTH radioimmunoassay were studied in 10 patients with Cushing's disease before and after treatment, three patients with Cushing's syndrome with adrenal tumours, one Nelson's syndrome patient; 13 patients with Addison's disease and 12 patients with hypo-pituitarism. Twenty-seven normal subjects were controls. The measurement of basal plasma ACTH gave good differentiation between: a. pituitary Cushing's disease from adrenal tumors; b. Addison's disease from hypo-pituitarism. However this assay has a limited value for the differentiation between Cushing's disease from normal subjects and it is often unhelpful in the differential diagnosis of hypo-pituitarism from normal subjects. (author)

  15. Radioimmunoassay for the middle region of human parathyroid hormone: comparison of two radioiodinated synthetic peptides

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, M.E.; Marx, S.J. (National Institute of Arthritis, Diabetes, and Digestive and Kidney Diseases, Bethesda, MD (USA))

    1985-01-01

    Two synthetic peptides were evaluated to develop radioligands for midregion-specific radioimmunoassay (RIA) of human parathyroid hormone (hPTH). Both radioligands were tested using three anti-PTH sera of proven clinical utility. While each of these midregion-directed antisera showed unique specificity, they all reacted with high affinity with both radioligands and none of them discriminated significantly between the two synthetic midregion peptides. Analysis of data on the relation of serum calcium and hPTH midregion immunoreactivity showed a useful separation of groups (all nonazotemic) with primary hyperparathyroidism, secondary hyperparathyroidism, primary hypoparathyroidism and secondary hypoparathyroidism.

  16. Radioimmunoassay for vasopressin: plasma levels after stimulation by I-V nicotine injection

    International Nuclear Information System (INIS)

    Conte-Devolx, B.; Rougon-Rapuzzi, G.; Millet, Y.

    1976-01-01

    A radioimmunoassay for vasopressin which permits the estimation of plasma levels as low as 0.25μIU/ml was developed. The average plasma level of ADH after overnight water restriction was found to be 5.20μIU/ml. A hypersecretion of ADH was provoked by the intravenous injection of 1-2mg of nicotine. In 10 volunteer subjects this stimulation by nicotine provoked ADH secretion which reached a maximum between 2 and 15 minutes after injection; the hormone plasma level reached an average value of 21.3μIU/ml [fr

  17. A sensitive radioimmunoassay of parathyroid hormone in human serum using a specific extraction procedure

    International Nuclear Information System (INIS)

    Christensen, M.S.

    1976-01-01

    A radioimmunoassay of human parathyroid hormone (PTH) is described. PTH was extracted from serum by adsorption to and elution from microfine silica, causing a 3.2-fold greater hormone concentration in extract than in serum. The extraction procedure eliminated from the assay unspecific interference caused by serum factors. The detection limit was 10 pg bovine PTH. The concentration of PTH was measurable in serum from 95 % of normal subjects (mean, 68 pg/ml; S.D., 18), was undetectable in sera from hypoparathyroid patients, and elevated in 96 % of sera from patients with primary hyperthyroidism. The data presented suggest that the assay mainly measures PTH(1-84). (Auth.)

  18. Prospective study of radioimmunoassay for antibodies against neutrophil cytoplasm in diagnosis of systemic vasculitis

    Energy Technology Data Exchange (ETDEWEB)

    Savage, C.O.S.; Winearls, C.G.; Jones, S.; Marshall, P.D.; Lockwood, C.M.

    1987-06-20

    The diagnosis and management of Wegener's granulomatosis and microscopic polyarteritis are complicated by the lack of specific diagnostic tests. The diagnostic performance of a solid-phase radioimmunoassay, which detects the autoantibodies against neutrophil cytoplasm present in these disorders, was assessed in a prospective study of patients with suspected vasculitis and/or rapidly progressive nephritis. The assay had a sensitivity and specificity of 96% when carried out in combination with a specific inhibition stage and indirect immunofluorescence staining of alcohol-fixed normal neutrophils.

  19. 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

  20. 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)

  1. 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.

  2. Radioimmunoassay of gastrin level in duodenal ulcer, atrophic gostritis and Addison-Biermer's disease

    International Nuclear Information System (INIS)

    Hasik, J.; Kozal, H.; Kosowicz, J.; Hansz, J.

    1975-01-01

    Radioimmunoassay of gastrin level in the blood was performed in 20 controls, 12 patients with duodenal ulcer, 13 patients with atrophic gastritis and 14 patients with Addison-Biermer's disease. Gastrin level in the serum of the patients with duodenal ulcer did not differ significantly from that of controls. In atrophic gastritis and particularly in Addison-Biermer's disease gastrin level was found to be several times higher. This is probably a result of chronic gastrin secretion stimulation which is normally inhibited by gastric juice. (author)

  3. Prospective study of radioimmunoassay for antibodies against neutrophil cytoplasm in diagnosis of systemic vasculitis

    International Nuclear Information System (INIS)

    Savage, C.O.S.; Winearls, C.G.; Jones, S.; Marshall, P.D.; Lockwood, C.M.

    1987-01-01

    The diagnosis and management of Wegener's granulomatosis and microscopic polyarteritis are complicated by the lack of specific diagnostic tests. The diagnostic performance of a solid-phase radioimmunoassay, which detects the autoantibodies against neutrophil cytoplasm present in these disorders, was assessed in a prospective study of patients with suspected vasculitis and/or rapidly progressive nephritis. The assay had a sensitivity and specificity of 96% when carried out in combination with a specific inhibition stage and indirect immunofluorescence staining of alcohol-fixed normal neutrophils. (author)

  4. Specific radioimmunoassay of HCG and its α and β subunits: methods and results

    International Nuclear Information System (INIS)

    Reuter, A.M.; Schoonbrood, J.; Franchimont, P.

    1976-01-01

    To create antisera that are specific for the radioimmunoassay of HCG and its subunits, the antisera are neutralized by incubation with LH or HCG. For each RIA system the inhibition curves of HCG and its subunits LH, FSH, TSH and STH are obtained. The 125 I labelled hormones HCG, α and β subunits and LH were chromatographed over a Sephadex G 100 column. Serum of menopausal and pregnant women were chromatographed in the same way and the fractions subjected to RIA. HCG and its subunits were determined by RIA in the sera of patients with different kinds of cancer

  5. A radioimmunoassay for the detection of diethylstilboestrol and related stilbenes in biological fluids

    International Nuclear Information System (INIS)

    Hallahan, Cornelius; McGarry, Yvonne; Collins, J.D.

    1985-01-01

    A radioimmunoassay for the measurement of the synthetic anabolic agent diethylstilboestrol (DES) is described. It is based on a commercially available antiserum and a tritiated derivative of DES. The method can detect low concentrations of residues (less than 0.5 ng/ml) in small samples (0.05 to 0.2 ml) of biological fluids. DES was measured in plasma, bile and urine obtained from a calf slaughtered 22 days after subcutaneous implantation of 24 mg DES. The assay described is suitable as a rapid screening procedure for identifying animals treated with stilbene substances. (author)

  6. Isolation of a somatomedin binding protein from human preterm amniotic fluid: development of a radioimmunoassay

    International Nuclear Information System (INIS)

    Drop, S.L.S.

    1983-01-01

    This thesis investigates the nature and biological behaviour of a somatomedin binding protein, identified in preterm amniotic fluid (AF). For that purpose a double antibody radioimmunoassay was developed. Purified AF binding protein (AFBP) was iodinated by the chloramine-T method, and dilutions of partially purified AFBP were designated as the standard, with the results expressed in μg equivalent protein/ml. The sensitivity of the assay was improved by adoption of the nonequilibrium procedure. AFBP values were twice as high in preterm AF as in term AF. (Auth.)

  7. Application of pregnancy specific β1 glycoprotein-radioimmunoassay (SP1-ria) in obstetrics and gynecology

    International Nuclear Information System (INIS)

    Zhang Weiyuan

    1988-01-01

    Serum SP 1 values of 395 patients were determined by radioimmunoassay. It was found that SP 1 was apparently absent from the blood of normal men and nonpregnant women, increased with gestational stage in pregnant women, and was highest in late pregnancy. In high-risk pregnancy, SP 1 was lower than normal pregnamey group (PC0.01) could also be detected in ectopic pregnancy. In patients with benign and malignant hydatidiform mole, and choriocarcinoma, AP 1 level decreased with malignant degree. The authors suggest that measurement of SP 1 levels is a valuable index for monitoring high-risk pregnancy, diagnosing ectopic pregnancy and following-up trophoblastic cell diseases

  8. Radioimmunoassay of pharmacologically active compounds: applications to nicotine and its metabolites

    International Nuclear Information System (INIS)

    Langone, J.J.; Vunakis, H. van

    1979-01-01

    Since nicotine is the major tobacco alkaloid, its role in cardiovascular disease, cancer and other physiological effects of cigarette smoking has been the subject of intensive investigation for many years. As part of this investigation into the biochemical and physiological effects of nicotine, the authors developed sensitive and specific radioimmunoassays for the parent alkaloid, a major metabolite cotinine, and for γ-(3-pyridyl)-γ-oxo-N-methylbutyramide (oxoamide). The oxoamide is a minor metabolite derived from cotinine. The authors describe the development of these RIA's and demonstrate their use in determining levels of these compounds in physiological fluids of smokers and in studying metabolic processes in vitro. (Auth.)

  9. Preparation of quality control samples in radioimmunoassay for thyroid stimulating hormone (TSH)

    International Nuclear Information System (INIS)

    Ali, O.M.

    2006-03-01

    To days, the radioimmunoassay is becomes the best technique to analysis different concentrations of substance, especially in medical and research laboratories. Although the specificity of RIA techniques, the quality controls must takes place to give good results as possible. In this dissertation i prepared quality control samples of thyroid stimulating hormone (TSH), to use it in RIA techniques and to control the reliability results of those laboratories which used these methods. We used China production kits of RIA method to determine the level of hormone (low-normal-high) concentration. Statistical parameters were used to drown the control chart of the mean to these data.(Author)

  10. Preparation of quality control samples for thyroid hormones T3 and T4 in radioimmunoassay techniques

    International Nuclear Information System (INIS)

    Ahmed, F.O.A.

    2006-03-01

    Today, the radioimmunoassay becomes one of the best techniques for quantitative analysis of very low concentration of different substances. RIA is being widely used in medical and research laboratories. To maintain high specificity and accuracy in RIA and other related techniques the quality controls must be introduced. In this dissertation quality control samples for thyroid hormones (Triiodothyronine T3 and Thyroxin T4), using RIA techniques. Ready made chinese T4, T3 RIA kits were used. IAEA statistical package were selected.(Author)

  11. Radioimmunoassay for the middle region of human parathyroid hormone: comparison of two radioiodinated synthetic peptides

    International Nuclear Information System (INIS)

    Sharp, M.E.; Marx, S.J.

    1985-01-01

    Two synthetic peptides were evaluated to develop radioligands for midregion-specific radioimmunoassay (RIA) of human parathyroid hormone (hPTH). Both radioligands were tested using three anti-PTH sera of proven clinical utility. While each of these midregion-directed antisera showed unique specificity, they all reacted with high affinity with both radioligands and none of them discriminated significantly between the two synthetic midregion peptides. Analysis of data on the relation of serum calcium and hPTH midregion immunoreactivity showed a useful separation of groups (all nonazotemic) with primary hyperparathyroidism, secondary hyperparathyroidism, primary hypoparathyroidism and secondary hypoparathyroidism. (Auth.)

  12. Computer assessment of the informative value of radioimmunoassays for the diagnosis of stomach cancer

    International Nuclear Information System (INIS)

    Ozherel'ev, A.S.; Tkacheva, G.A.; Glazkova, T.G.

    1987-01-01

    Solution rules in the form of differential-diagnositc tables with coefficients of weight and threshold values of 16 different signs were obtained with the help of a computer EC-assisted algorithm of a generalized picture. These signs included tumor antigens, cyclonucleotides and hormones determined in the blood serum of healthy individuals, stomach cancer patients and patients with diseases of nonmalignant origin by means of radioimmunoassay. These signs being of low informative value by themselves, in a combined use provided an opportunity to differentiate between ''stomach cancer-not cancer'' with a sufficiently high degree of significance

  13. Sample preparation for measuring cow's progesterone in radioimmunoassay technique application

    International Nuclear Information System (INIS)

    Nuning Duria; Budi Santoso; Nuniek Lelananingtiyas; Wiranto Budi Santoso

    2010-01-01

    Sample preparation for measuring cow's progesterone in radioimmunoassay technique application has been done. Preparation includes the preparation of samples of cow's milk samples that has been carried out artificial insemination on day 0, 11 and 21. Then the standard making of progesterone in the form of fresh milk or skim milk (non fat) that has been removed its progesterone and through a series of chemical processes. The last is the preparation work on samples using the RIA kit I 125 . With this milk samples preparation, samples can be counted using RIA counter so that concentration of progesterone hormone can be determined accurately. (author)

  14. Heterotypic reactions in a radioimmunoassay for coxsackie B virus specific IgM.

    Science.gov (United States)

    Pugh, S F

    1984-01-01

    IgM antibody capture radioimmunoassays were developed to detect coxsackie virus B1-B5 specific IgM. Specific IgM was detected in sera from all patients with coxsackie B virus infections proved by isolation; however, sera from 13/32 patients with rising neutralising antibody titres were negative in the assay. Frequent heterotypic responses were seen among the positive sera. Thirty seven patients with other enterovirus infections were also studied, and sera from 15 of these patients reacted in the assay, showing that heterotypic coxsackie B IgM responses occur not only in coxsackie B virus infections but also in other enterovirus infections. PMID:6323548

  15. Flow Cytometric Bead Sandwich Assay Based on a Split Aptamer.

    Science.gov (United States)

    Shen, Luyao; Bing, Tao; Liu, Xiangjun; Wang, Junyan; Wang, Linlin; Zhang, Nan; Shangguan, Dihua

    2018-01-24

    A few aptamers still bind their targets after being split into two moieties. Split aptamers have shown great potential in the development of aptameric sensors. However, only a few split aptamers have been generated because of lack of knowledge on the binding structure of their parent aptamers. Here, we report the design of a new split aptamer and a flow cytometric bead sandwich assay using a split aptamer instead of double antibodies. Through DMS footprinting and mutation assay, we figured out the target-binding moiety and the structure-stabilizing moiety of the l-selectin aptamer, Sgc-3b. By separating the duplex strand in the structure-stabilizing moiety, we obtained a split aptamer that bound l-selectin. After optimization of one part of the split sequence to eliminate the nonspecific binding of the split sequence pair, we developed a split-aptamer-based cytometric bead assay (SACBA) for the detection of soluble l-selectin. SACBA showed good sensitivity and selectivity to l-selectin and was successfully applied for the detection of spiked l-selectin in the human serum. The strategies for generating split aptamers and designing the split-aptamer-based sandwich assay are simple and efficient and show good practicability in aptamer engineering.

  16. Human CCDC47 sandwich immunoassay development with electrochemiluminescence technology.

    Science.gov (United States)

    Wu, Wenfang S; Zhu, Liang; Patil, Saurabh; Gokul, Karthiga; Reilly, Sean; Chan, Joyce; Tekumalla, Poornima; Vishnudas, Vivek; Kiebish, Michael A; Sarangarajan, Rangaprasad; Akmaev, Viatcheslav R; Kellogg, Mark D; Narain, Niven R

    2018-01-01

    Coiled-Coil Domain Containing 47 (CCDC47) is an endoplasmic reticulum (ER) transmembrane protein involved in calcium signaling through utilization of its calcium binding-acidic luminal domain. CCDC47 also interacts with ERAD (endoplasmic reticulum-associated degradation) complex and is involved in ER stress relief. In this report, we developed human CCDC47 monoclonal antibodies and a sandwich immunoassay for CCDC47 measurement in biological matrices. Specificity of developed antibodies were confirmed by immunoblot and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of immunoprecipitated cell lysates. To achieve high analytical sensitivity, traditional colorimetric enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence (ECL) technology were compared, and 3 logs of increased sensitivity was observed with the use of ECL. A CCDC47 sandwich ECL assay was subsequently developed and performances evaluated for calibration curves, precision and accuracy, as well as selectivity and interferences for sample measurement. Sample stability was also characterized for freeze/thaw cycles and short/long term storage conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Impact performance of nanophased foam core sandwich composites

    Energy Technology Data Exchange (ETDEWEB)

    Hosur, M.V. [Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States)], E-mail: mhosur@gmail.com; Mohammed, A.A.; Zainuddin, S.; Jeelani, S. [Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States)

    2008-12-20

    In this study, sandwich panels were fabricated with neat and nanophased foam core and three-layered plain weave carbon fabric/Sc-15 epoxy composite face sheets. Neat and nanophased foam cores with Nanocor I-28E nanoclay at a loading of 0.5% and 1% by weight were prepared. Sandwich panels were then fabricated using co-injection resin transfer molding process. Samples of size 100 mm x 100 mm were then cut from the panels and subjected to low-velocity impact loading using an instrumented impact test setup. Impact response of the panels was recorded and analyzed in terms of peak load, absorbed energy, time and deflection at peak load. The tested samples were then sectioned into two halves and scanned using a scanner, optical and scanning electron microscopes to understand the failure patterns. Samples with nanophased foam sustained higher loads and had lower damage areas as compared with neat counterparts. Nanophased foam cores exhibited relatively more brittle fracture.

  18. Foam-injected sandwich panels with continuous-reinforced facings

    Science.gov (United States)

    Menrath, A.; Henning, F.; Huber, T.; Roch, A.; Riess, C.

    2014-05-01

    Thermoplastic foam injection molding (FIM) in combination with insert molding (IM) offers a possibility to generate sandwich panels in a one-step process. The prepared face sheets are first positioned inside the mold. A preheating process is carried out using quartz infrared emitters, which are mounted on a linear robot, before the mold is closed. The injection of the gas/melt mixture is combined with an embossing of the mold to further improve the face-core-adhesion. Finally, to initiate the foaming process, adjust the extent of foaming of the core and achieve the desired component dimensions, a mold opening stroke is carried out. The process described was performed with different facing materials, layer dimensions and overall wall thicknesses. Drawn PP fabrics (Curv®) as well as PP/GF70 tapes and consolidated sheets (unidirectional) were used to generate sandwich panels in a range of 5 to 6.4 mm thickness. PP was also chosen to form the foamed core which, in combination with the Curv® face sheets, produces a fully recyclable self-reinforced polymer (SRP) composite. Detailed process descriptions and the results of bending tests demonstrate the high potential. Other focuses are the preheating process and the foam structure.

  19. First record of a banded Sandwich Tern (Thalasseus sandvicensis) moving from England to the United States

    Science.gov (United States)

    Spendelow, Jeffrey A.

    2015-01-01

    A Sandwich Tern (Thalasseus sandvicensis sandvicensis) banded as a chick in 2002 at Coquet Island off the northeast coast of Great Britain was observed at two locations on Cape Cod, Massachusetts, USA, in August and September 2013. This is the first record of a banded Sandwich Tern from the United Kingdom being observed in the United States.

  20. Failure of uniformly compression loaded debond damaged sandwich panels — An experimental and numerical study

    DEFF Research Database (Denmark)

    Moslemian, Ramin; Quispitupa, Amilcar; Berggreen, Christian

    2012-01-01

    This paper deals with the failure of compression-loaded sandwich panels with an implanted circular face/core debond. Uniform compression tests were conducted on intact sandwich panels with three different types of core material (H130, H250 and PMI) and on similar panels with circular face...

  1. Laser welded steel sandwich panel bridge deck development : finite element analysis and stake weld strength tests.

    Science.gov (United States)

    2009-09-01

    This report summarizes the analysis of laser welded steel sandwich panels for use in bridge structures and : static testing of laser stake welded lap shear coupons. Steel sandwich panels consist of two face sheets : connected by a relatively low-dens...

  2. Improving Performance of Polymer Fiber Reinforced Sandwich X-Joints in Naval Vessels

    DEFF Research Database (Denmark)

    Lundsgaard-Larsen, Christian; Berggreen, Christian; Karlsen, Kasper

    2007-01-01

    This study deals with damage tolerance of sandwich X-joints with embedded debond damages between face and core. The study is conducted both through modeling and full-scale tests. Mixed mode cohesive laws from the opening of sandwich interfaces are determined experimentally from a DCB specimen loa...

  3. The Effect of Face Sheet Wrinkle Defects on the Strength of FRP Sandwich Structures

    DEFF Research Database (Denmark)

    Hayman, Brian; Berggreen, Christian; Pettersson, Robert

    2007-01-01

    . In the studies reported here, the influence of wrinkle defects on the in-plane compressive strength of quasi-isotropic carbon fiber reinforced plastic (CFRP) laminates used in PVC foam-cored sandwich panels has been investigated by three approaches: testing of sandwich beam specimens in four-point bending...

  4. Robust and Air-Stable Sandwiched Organo-Lead Halide Perovskites for Photodetector Applications

    KAUST Repository

    Mohammed, Omar F.

    2016-02-25

    We report the simplest possible method to date for fabricating robust, air-stable, sandwiched perovskite photodetectors. Our proposed sandwiched structure is devoid of electron or hole transporting layers and also the expensive electrodes. These simpler architectures may have application in the perovskite-only class of solar cells scaling up towards commercialization.

  5. Failure Investigation of Debonded Sandwich Columns: An Experimental and Numerical Study

    DEFF Research Database (Denmark)

    Moslemian, Ramin; Berggreen, Christian; Carlsson, Leif A.

    2009-01-01

    Failure of compression loaded sandwich columns with an implanted through-width face/core debond is examined. Compression tests were conducted on sandwich columns containing implemented face/core debonds. The strains and out-of-plane displacements of the debonded region were monitored using the di...

  6. Face/core debond fatigue crack growth characterization using the sandwich mixed mode bending specimen

    DEFF Research Database (Denmark)

    Manca, Marcello; Quispitupa, Amilcar; Berggreen, Christian

    2012-01-01

    Face/core fatigue crack growth in foam-cored sandwich composites is examined using the mixed mode bending (MMB) test method. The mixed mode loading at the debond crack tip is controlled by changing the load application point in the MMB test fixture. Sandwich specimens were manufactured using H45...

  7. Research overview of design method of super light multi-hole class- honeycomb sandwich structure materials

    Directory of Open Access Journals (Sweden)

    Xiang LI

    Full Text Available With the sandwich structure materials' application and promotion in the field of engineering continuously, existing sandwich structure material gradually cannot meet the design requirements. It is very urgent to develop new sandwich structure materials of high efficiency, energy saving and easy to process. The project puts forward and constructs a new kind of class-honeycomb sandwich structure material combined with important application backgrounds that super light and high strength metal sandwich structure materials are applied into the high weight and high energy consumption equipments of automobile, aerospace and machinery and so on. This research involve: mechanical properties equivalent method for the class-honeycomb sandwich structure and its core; Strength, stiffness and inherent frequency characteristic and failure criterions of the class-honeycomb sandwich structure; based on the failure criterions constructing the multiple-constraint models of the class-honeycomb sandwich structure. The research tries to put forward a new method for innovative design of lightweight material and structure and new ideas of lightweight technology research in theory and practice.

  8. Applications of radioimmunoassay techniques in endocrine studies. Part of a coordinated programme on in vitro assay techniques

    International Nuclear Information System (INIS)

    Marusic, E.T.

    1977-04-01

    The final report consists of a description of the research done, a reference to where the abstract of the results obtained was published, and a list of the corresponding publications and of those in preparation. Work has been done on radioimmunoassay techniques for measuring plasma corticoid values, plasma renin activity (with own reagents), and clinical and research studies measuring aldosterone, corticosterone, and cortisol in control and hypophysectomized patients. Diagnosis of primary aldosteronism has been initiated by radioimmunoassay techniques. Another study concerned the mechanism of K ions on aldosterone production

  9. 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)

  10. Natural Cork Agglomerate Employed as an Environmentally Friendly Solution for Quiet Sandwich Composites

    Science.gov (United States)

    Sargianis, James; Kim, Hyung-ick; Suhr, Jonghwan

    2012-01-01

    Carbon fiber-synthetic foam core sandwich composites are widely used for many structural applications due to their superior mechanical performance and low weight. Unfortunately these structures typically have very poor acoustic performance. There is increasingly growing demand in mitigating this noise issue in sandwich composite structures. This study shows that marrying carbon fiber composites with natural cork in a sandwich structure provides a synergistic effect yielding a noise-free sandwich composite structure without the sacrifice of mechanical performance or weight. Moreover the cork-core sandwich composites boast a 250% improvement in damping performance, providing increased durability and lifetime operation. Additionally as the world seeks environmentally friendly materials, the harvesting of cork is a natural, renewable process which reduces subsequent carbon footprints. Such a transition from synthetic foam cores to natural cork cores could provide unprecedented improvements in acoustic and vibrational performance in applications such as aircraft cabins or wind turbine blades. PMID:22574250

  11. Behavior of composite sandwich panels with several core designs at different impact velocities

    Science.gov (United States)

    Jiga, Gabriel; Stamin, Ştefan; Dinu, Gabriela

    2018-02-01

    A sandwich composite represents a special class of composite materials that is manufactured by bonding two thin but stiff faces to a low density and low strength but thick core. The distance between the skins given by the core increases the flexural modulus of the panel with a low mass increase, producing an efficient structure able to resist at flexural and buckling loads. The strength of sandwich panels depends on the size of the panel, skins material and number or density of the cells within it. Sandwich composites are used widely in several industries, such as aerospace, automotive, medical and leisure industries. The behavior of composite sandwich panels with different core designs under different impact velocities are analyzed in this paper by numerical simulations performed on sandwich panels. The modeling was done in ANSYS and the analysis was performed through LS-DYNA.

  12. Optimum Design of Composite Sandwich Structures Subjected to Combined Torsion and Bending Loads

    Science.gov (United States)

    Li, Xiang; Li, Gangyan; Wang, Chun H.; You, Min

    2012-06-01

    This research is motivated by the increase use of composite sandwich structures in a wide range of industries such as automotive, aerospace and civil infrastructure. To maximise stiffness at minimum weight, the paper develops a minimum weight optimization method for sandwich structure under combined torsion and bending loads. We first extend the minimum-weight design of sandwich structures under bending load to the case of torsional deformation and then present optimum solutions for the combined requirements of both bending and torsional stiffness. Three design cases are identified for a sandwich structure required to meet multiple design constraints of torsion and bending stiffness. The optimum solutions for all three cases are derived. To illustrate the newly developed optimum design solutions, numerical examples are presented for sandwich structures made of either isotropic face skins or orthotropic composite face skins.

  13. Natural cork agglomerate employed as an environmentally friendly solution for quiet sandwich composites.

    Science.gov (United States)

    Sargianis, James; Kim, Hyung-ick; Suhr, Jonghwan

    2012-01-01

    Carbon fiber-synthetic foam core sandwich composites are widely used for many structural applications due to their superior mechanical performance and low weight. Unfortunately these structures typically have very poor acoustic performance. There is increasingly growing demand in mitigating this noise issue in sandwich composite structures. This study shows that marrying carbon fiber composites with natural cork in a sandwich structure provides a synergistic effect yielding a noise-free sandwich composite structure without the sacrifice of mechanical performance or weight. Moreover the cork-core sandwich composites boast a 250% improvement in damping performance, providing increased durability and lifetime operation. Additionally as the world seeks environmentally friendly materials, the harvesting of cork is a natural, renewable process which reduces subsequent carbon footprints. Such a transition from synthetic foam cores to natural cork cores could provide unprecedented improvements in acoustic and vibrational performance in applications such as aircraft cabins or wind turbine blades.

  14. Fracture Testing of Honeycomb Core Sandwich Composites Using the DCB-UBM Test

    DEFF Research Database (Denmark)

    Saseendran, Vishnu; Berggreen, Christian; Carlsson, Leif A.

    2015-01-01

    Face/core debonds in sandwich structures cause loss of integrity of sandwich structures. The debond problem in honeycomb core sandwich composites has not been widely studied. A suitable fracture approach coupled with experimental validation is paramount to determine the fracture resistance...... of the face/core interface. In this paper, a novel test-rig exploiting the double cantilever beam-uneven bending moments (DCB-UBM) concept is used to determine the fracture toughness of aircraft type honeycomb core sandwich composites as a function of the phase angle (mode-mixity), within the framework...... are able to slide on rails to follow the specimen’s deformation kinematics when subjected to pure rotations, as schematically shown in Figure 1. The robustness of the new test rig is demonstrated by performing pure mode-I fracture characterization of the face/core interface of a typical aircraft sandwich...

  15. Two-site jumps in dimethyl sulfone studied by one- and two-dimensional 17O NMR spectroscopy

    Science.gov (United States)

    Beerwerth, J.; Storek, M.; Greim, D.; Lueg, J.; Siegel, R.; Cetinkaya, B.; Hiller, W.; Zimmermann, H.; Senker, J.; Böhmer, R.

    2018-03-01

    Polycrystalline dimethyl sulfone is studied using central-transition oxygen-17 exchange NMR. The quadrupolar and chemical shift tensors are determined by combining quantum chemical calculations with line shape analyses of rigid-lattice spectra measured for stationary and rotating samples at several external magnetic fields. Quantum chemical computations predict that the largest principal axes of the chemical shift anisotropy and electrical field gradient tensors enclose an angle of about 73°. This prediction is successfully tested by comparison with absorption spectra recorded at three different external magnetic fields. The experimental one-dimensional motionally narrowed spectra and the two-dimensional exchange spectrum are compatible with model calculations involving jumps of the molecules about their two-fold symmetry axis. This motion is additionally investigated by means of two-time stimulated-echo spectroscopy which allows for a determination of motional correlation functions over a wider temperature range than previously reported using carbon and deuteron NMR. On the basis of suitable second-order quadrupolar frequency distributions, sin-sin stimulated-echo amplitudes are calculated for a two-site model in the limit of vanishing evolution time and compared with experimental findings. The present study thus establishes oxygen-17 NMR as a powerful method that will be particularly useful for the study of solids and liquids devoid of nuclei governed by first-order anisotropies.

  16. The effect of alternative seismotectonic models on PSHA results - a sensitivity study for two sites in Israel

    Science.gov (United States)

    Avital, Matan; Kamai, Ronnie; Davis, Michael; Dor, Ory

    2018-02-01

    We present a full probabilistic seismic hazard analysis (PSHA) sensitivity analysis for two sites in southern Israel - one in the near field of a major fault system and one farther away. The PSHA analysis is conducted for alternative source representations, using alternative model parameters for the main seismic sources, such as slip rate and Mmax, among others. The analysis also considers the effect of the ground motion prediction equation (GMPE) on the hazard results. In this way, the two types of epistemic uncertainty - modelling uncertainty and parametric uncertainty - are treated and addressed. We quantify the uncertainty propagation by testing its influence on the final calculated hazard, such that the controlling knowledge gaps are identified and can be treated in future studies. We find that current practice in Israel, as represented by the current version of the building code, grossly underestimates the hazard, by approximately 40 % in short return periods (e.g. 10 % in 50 years) and by as much as 150 % in long return periods (e.g. 10E-5). The analysis shows that this underestimation is most probably due to a combination of factors, including source definitions as well as the GMPE used for analysis.

  17. Radioimmunoassay measurements of serum thyrotropin in patients with hypothalamic-pituitary and thyroid diseases

    International Nuclear Information System (INIS)

    Miyai, Kiyoshi; Azukizawa, Mizuo; Azukizawa, Hisako; Hosokawa, Mitsuko; Nishi, Keiko

    1975-01-01

    Serum TSH was measured by means of double antibody radioimmunoassay using a commercial Kit Daiichi, in 21 normal subjects, 200 patients with thyroid disease and 130 patients with hypothalamic-pituitary diseases. Serum TSH concentrations in normal subjects were <2 to 8 μU/ml which rose to 8-40 μU/ml after administration of 500 μg TRH intravenously. Serum TSH was undetectable and did not respond to TRH in all untreated patients and in some euthyroid patients with Graves' disease after treatment. Undetectable TSH and no response to TRH were also observed in most patients with a hyperfunctioning thyroid nodule and those with subacute thyroiditis in the acute phase. In some patients with Hashimoto's thyroiditis and all patients with adult myxedema and cretinism, serum TSH levels were increased and showed hyperresponse to TRH. The ratio of bioassay and radioimmunoassay potency estimates for TSH in sera obtained before TRH was not statistically different from that obtained after TRH administration to patients with primary hypothyroidism. Elevated serum TSH was promptly decreased by the administration of thyroid hormone to the patients. More than 50% of patients with pituitary adenoma, acromegaly and craniopharyngioma showed normal basal TSH and no or low response of TSH to TRH. Administration of TRH failed to stimulate a rise in serum TSH in 2 sisters with isolated TSH deficiency with cretinism. Basal TSH was undetectable and showed delayed response to TRH in patients with anorexia nervosa. (auth.)

  18. Radioimmunoassay of total and specific E immunoglobulin. Variations with different parameters in allergic subjects

    International Nuclear Information System (INIS)

    Le Sellin, James.

    1977-05-01

    Owing to the work of 'Ishizaka' and of Johansson and Bennich the discovery of E immunoglobulin (IgE) marks an important stage in the diagnosis of atopic hypersensitivity. However certain limits in the analysis methods must be known to allow better interpretation of the results. The radioimmunoassay of total and specific IgE is still one of the most precise. Our work is divided into two parts: - the first is devoted to a general review on IgE; - the second reports our own study carried out on 371 allergic subjects. Each of these patients was analysed for total IgE by the PRIST radioimmunological method (paper radioimmuno sorbent test) and for IgE specific to one or more antigens by the RAST method (radioallergo sorbent test). A radioimmunoassay of total and specific IgE must be interpreted as a function of clinical data. While the assay can never become systematic it may be used to confirm or back up an atopic hypersensitivity diagnosis in cases where the clinical signs are inadequate [fr

  19. Measurement of IgG-blocking antibodies: development and application of a radioimmunoassay

    International Nuclear Information System (INIS)

    Sobotka, A.K.; Valentine, M.D.; Ishizaka, K.; Lichtenstein, L.M.

    1976-01-01

    A radioimmunoassay for measuring blocking antibodies has been developed. We used the ragweed antigen E system to show that the same blocking antibodies (IgG) measured by inhibition of antigen-induced leukocyte histamine release were precipitated in the binding assay (r/sub s/ = 0.96 p less than 0.001), thus validating a widely applicable technique for measuring blocking antibodies. Binding of phospholipase-A (Phos-A), the major allergen in honey bee venom, was also shown to correlate significantly with inhibition of histamine release. Hymenoptera (insect) hypersensitivity was used as a model to demonstrate application of the binding assay. Sera obtained from patients undergoing whole body extract therapy contained negligible amounts of specific blocking antibodies. Significantly higher blocking antibody titers to both whole honey bee venom and Phos-A were measured in sera drawn from patients immunized with whole venom. The use of the binding radioimmunoassay should facilitate management of allergic disease processes in which blocking antibodies are thought to be protective

  20. Radioimmunoassay of alpha-foeto-protein in hepatology. Observation of 151 cases

    International Nuclear Information System (INIS)

    Dao, Mouhamadou.

    1976-03-01

    Alpha-foeto-protein, although discovered several years ago, was considered as only able to exist in primary adult liver cancer. With progress in science and in research it was observed that AFP can be found in normal subjects, without any pathological significance. APF has been found moreover in illnesses other than primary liver cancer. This range of diseases, restricted at first, has continued to widen, a development due to the discovery of new AFP detection methods and radioimmunoassay. Our work, covering 151 cases discussed in detail in the 'Material and Methods' chapter, is interesting from two viewpoints: in hepatology it is useful to know whether the very sensitive radio-immunological method reveals abnormal AFP content variations in different liver diseases; given the large number of hepatomas in our series it is also interesting to have the value of this determination confirmed in primary liver cancer diagnosis. Radioimmunoassay now replaces other quantitative methods (MANCINI's radial immunodiffusion and LAURELL's elec. diffusion) and is the most accurate [fr