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Immunoassay System (immunoassay + system)

Distribution by Scientific Domains

Medical Sciences	44%

Selected Abstracts

Clinical application of an enzyme immunoassay for cholecystokinin-like immunoreactive substance for determination of the human plasma levels: the effect of metoclopramide on gastrointestinal peptides and stress-related hormones

JOURNAL OF PEPTIDE SCIENCE, Issue 5 2006
Fumihiko Katagiri
Abstract Metoclopramide, a prokinetic drug, is widely used to treat vomiting and nausea. Delayed gastric emptying and continual stress are considered important factors, among others, that induce nausea and vomiting. One gastrointestinal motility regulatory factor has been assumed to be the induction of changes in the levels of peptides such as gastrin, somatostatin, motilin, and cholecystokinin (CCK) in plasma. In contrast, adrenocorticotropic hormone (ACTH) and cortisol are used as indicators of stress. Here, we studied the effects of metoclopramide on human plasma gastrin-, somatostatin-, motilin-, and CCK-like immunoreactive substances (ISs) and ACTH-IS and cortisol under stress conditions using repetitive blood sampling in healthy subjects. Metoclopramide hydrochloride at a dose of 30 mg or placebo was orally administered to five healthy male volunteers. Blood samples were taken before and 20, 40, 60, 90, 120, 180, and 240 min after administration, subject to extracting procedures, and submitted to a highly sensitive enzyme immunoassay system. A single administration of metoclopramide caused significant increases in plasma somatostatin-IS levels compared with the placebo. Metoclopramide significantly decreased plasma gastrin- and suppressed ACTH-IS and cortisol levels compared with the placebo. We hypothesize that metoclopramide might have an accelerating gastric-emptying effect and a modulatory effect on the hypothalamo-pituitary-adrenal (HPA) axis and the autonomic nervous function. These effects might be beneficial in stress-related diseases, which suggest that this medicine has clinicopharmacological activities. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd. [source]

Analysis of specific IgE and IgG subclass antibodies for diagnosis of Echinococcus granulosus

PARASITE IMMUNOLOGY, Issue 8 2006
A. R. KHABIRI
SUMMARY The potential roles of specific antibodies of different immunoglobulin G (IgG) subclasses and IgE in serological diagnosis of cystic echinococcosis (CE) were investigated by an enzyme linked immunosorbent assay (ELISA) based on Antigen 5 (Ag5). Presence of IgG1 was demonstrated in all sera from 58 patients with CE. The most discriminatory and specific antibodies found in this study belonged to IgG4 and IgE. Only one false-positive reaction was observed with IgG4 and no IgE cross-reactivity occurred with 40 sera from healthy controls. In 36 sera from patients infected with parasites other than CE two false-positive reactions with IgG4 were observed but none occurred with IgE. In immunoblotting, it was shown that IgG1 subclass was responsible for cross-reactivity of human antibodies that reacted with a 38 kDa subunit of Ag5. IgG4 and IgE antibodies could not recognize the 38 kDa subunit and under non-reducing conditions reacted with the 57 kDa subunit without any cross-reactivity to other parasites. The results demonstrated that IgG4 and IgE are the most important antibodies for serological diagnosis of hydatid cyst in an Ag5 based immunoassay system. [source]

Development of molecular immunoassay system for probiotics via toll-like receptors based on food immunology

ANIMAL SCIENCE JOURNAL, Issue 1 2008
Haruki KITAZAWA
ABSTRACT Recent interest has focused on the importance of intestinal immunity for the host defense, but to date, not much is known about the underlying mechanisms. The toll-like receptor (TLR) family plays an important role in host defense through recognizing bacterial pathogen-associated molecular patterns. Our recent research on the physiological function of food products has investigated the immunoregulatory effects of probiotic lactic acid bacteria (LAB) via TLR. Studies of swine, which often substitute for a human model, have demonstrated intestinal immunoregulation by the probiotic LAB mediated by TLR in the gut. On the basis of our study, efforts have also been made to develop a molecular immunoassay system for probiotic LAB and find novel immunostimulatory DNA sequences from probiotics and high potential immunobiotic LAB strains via TLR signaling. These findings may provide important clues at the molecular level on TLR signal transduction pathways and recognition mechanisms for the ligands. They also provide impetus to further delineate the activation mechanism of the innate immune response. In addition to identifying immunoregulatory factor immunogenics from LAB, a better understanding of intestinal immune regulation through cytokine networks holds out promise for basic food immunology research and the development of immunobiotic foods to prevent specific diseases. [source]

Advanced molecular immunoassay system for immunobiotic lactic acid bacteria using a transfectant of Toll-like receptor 2

ANIMAL SCIENCE JOURNAL, Issue 2 2007
Masanori TOHNO
ABSTRACT Toll-like receptor 2 (TLR2) is a receptor for a variety of microbial components, and it also mediates activation signals in the cell relating to the innate immune system. In order to evaluate the precise molecular immunoregulation by various strains of lactic acid bacteria (LAB) via TLR2, the swine TLR2 (sTLR2)-expressing transfectant was constructed using human embryonic kidney (HEK) 293 cells. It is demonstrated that intact immunobiotic LAB can induce immune responses through TLR2, and that different nuclear factor-,B (NF-,B) activities of various strains can be accurately detected by sTLR2-expressing HEK293 cells. Furthermore, cellular activation of NF-,B via TLR2 is reflected in enhanced binding and uptake of LAB. The sTLR2-expressing HEK293 cells were also useful for characterizing the expression pattern of type I helper T (Th1) and type II helper T (Th2) cytokines by the stimulation of immunobiotic LAB. These results suggest that sTLR2-expressing HEK293 cells may be useful in certain molecular immunoassay systems for producing new physiologically functional foods with intestinal immunomodulatory abilities, such as the maintenance of Th1/Th2 polarization. [source]

Clinical and radiological features of patients with macroprolactinaemia

CLINICAL ENDOCRINOLOGY, Issue 3 2003
Mark W. J. Strachan
Summary objectives Macroprolactin is a complex of prolactin (PRL) and IgG and may account for a significant proportion of cases of ,idiopathic hyperprolactinaemia'. In this study, we sought to determine the prevalence and clinical features of macroprolactinaemia in patients diagnosed with hyperprolactinaemia in our region, with a view to determining how patients with macroprolactinaemia should be investigated and managed. patients and methods An Immuno-1 automated immunoassay system with polyethylene glycol (PEG) precipitation was used to identify macroprolactin, with a recovery of , 50% taken as indicating significant macroprolactinaemia. Macroprolactin was found in 58 (21%) of 273 patients with a total PRL > 700 mU/l. The clinical records of 51 (44 female) were available for retrospective review. results The mean (range) age of patients was 39·5 (18,82) years. The median (range) concentrations for the various forms of PRL were: total PRL 1130 mU/l (728,5116), monomeric PRL 240 mU/l (50,656) and macroprolactin 895 mU/l (381,4854). Classical symptoms of hyperprolactinaemia were present in 39% of patients, although in many there were other possible explanations for their symptomatology. Pituitary adenomas were identified in six out of 36 people who underwent neuroimaging. Five of these patients had a microadenoma and one had a 10-mm macroadenoma (although, in this patient macroprolactin was identified after the discovery of the tumour). There was no relationship between macroprolactin concentrations and the presence of hyperprolactinaemic symptoms or neuroimaging abnormalities. conclusions Macroprolactinaemia is a common occurrence in patients with hyperprolactinaemia, but associated symptomatology may not necessarily be linked. The neuroimaging abnormalities were also probably incidental findings and it is questionable whether neuroimaging is necessary when significant macroprolactinaemia is identified and the concentration of monomeric PRL is not elevated (using the Immuno-1 assay system, following PEG precipitation). [source]

Advanced molecular immunoassay system for immunobiotic lactic acid bacteria using a transfectant of Toll-like receptor 2

Comparative evaluation of digoxin concentrations determined by three assay systems: TDx, IMx and OPUS

BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 1 2004
Yoshiyuki Kagawa
Abstract Digoxin concentrations measured by three automated immunoassay systems, i.e. OPUS, TDx and IMx assays, were compared in order to evaluate precision and accuracy performance, and data compatibility. Coefficients of variation for all methods in within-run and between-run precision were less than 10% at weighed-in concentrations of 0.545, 1.090 and 2.180 ng/ml. The accuracy relative to the three weighed-in concentrations ranged from 97% to 123% for all methods. One hundred and three plasma samples from 60 patients receiving digoxin were used to evaluate the data compatibility. Digoxin concentrations measured by the three immunoassay systems correlated well with one another. These results suggest that there are few problems when switching between digoxin assay methods, and that IMx and OPUS are more useful than TDx because they do not require sample pretreatment. The digoxin concentrations of the plasma samples from one patient receiving both digoxin and potassium canrenoate were investigated as a case report. The digoxin concentrations measured by TDx and IMx became higher than those measured by OPUS after starting the combination treatment. In another patient suffering from bilirubinaemia, the digoxin concentrations measured by TDx or IMx were higher than those measured by OPUS. These results suggest that OPUS has a higher specificity for measuring the plasma digoxin concentrations compared with TDx or IMx. Copyright © 2003 John Wiley & Sons, Ltd. [source]