Search results for "Assay"
showing 10 items of 2241 documents
A mitochondrial antigen-antibody system in cholestatic liver disease detected by radioimmunoassay.
2007
A radioimmunoassay (RIA) was established for the detection of antimitochondrial autoantibodies (AMAs) in patient sera. AMAs were detected by RIA in 12 of 14 patients with primary biliary cirrhosis and in 3 of 29 patients with chronic active hepatitis. AMAs were detected by indirect immunofluorescence in all sera positive by RIA. In addition, two patients with primary biliary cirrhosis and one patient with chronic active hepatitis were AMA positive when tested by indirect immunofluorescence, but negative when tested by RIA. AMAs were not detected by RIA or indirect immunofluorescence in 121 further patients with various hepatic and nonhepatic diseases, including healthy controls. The RIA det…
IgA anti-actin antibodies ELISA in coeliac disease: A multicentre study.
2007
Previous studies have demonstrated that serum anti-actin antibodies are a reliable marker of intestinal damage severity in coeliac disease.To validate in a multicentre study the clinical usefulness of serum IgA anti-actin antibody ELISA and its possible use in monitoring intestinal mucosa lesions during gluten-free diet.Four centres recruited 205 newly diagnosed coeliac disease patients with villous atrophy, 80 healthy controls and 81 "disease" controls. Twelve coeliac disease patients on gluten-free diet but with persistent symptoms underwent serum IgA anti-actin antibody assay and intestinal histology evaluation. IgA anti-actin antibody ELISA was performed with a commercial kit. All coeli…
Long-term storage in liquid nitrogen does not affect cell viability in cardiac valve allografts
2007
Liquid nitrogen is the most common medium used by tissue banks for the storage of cryopreserved heart valves. This study evaluates the effect of the length of storage on human cryopreserved heart valves. Human tissues (14 aortic and 13 pulmonary) were frozen in a controlled-rate freezer (1 degrees C/min) and stored in the liquid phase of a nitrogen tank for 9.1+/-1.6 years. The preservative solution was medium M199 containing 5% human serum albumin and 10% Me(2)SO. After thawing in a water bath at 42 degrees C, the cryoprotectant was removed. Then, fragments from vascular wall and leaflet were dissected. Explant cultures and histological studies were performed in order to assess cell viabil…
Establishing the upper reference limit of Galectin-3 in healthy blood donors
2017
Introduction Galectin-3 (Gal-3) is an independent predictor of poor outcomes and mortality in patients with heart failure (HF). Thus, it has been proposed as a reliable prognostic biomarker for HF. The definition of reference intervals is mandatory for interpreting the findings of experimental studies and encouraging the routine use of biomarkers in clinical practice. To date, no study assessed the reference intervals of Gal-3 and identified the biological variables that affect its concentration in a well-defined healthy population. The aim of this study was to determine the upper reference limit (URL) of Gal-3 in a highly reliable population of healthy subjects. Materials and methods We re…
Identification of a peptide mimicking the binding pattern of an antiphospholipid antibody
2006
Our objective was to characterize monoclonal antiphospholipid antibodies (APL) and identify disease-associated antigens in patients with the antiphospholipid syndrome (APS). We used the monoclonal antibody HL-5B, derived from a patient with APS suffering from multiple ischemic events, to screen a 12-mer peptide phage display library (New England Biolabs, London, England). The identified phage clones were sequenced and the derived consensus peptide was synthesized. The peptide was used to perform competitive inhibition experiments for their ability to inhibit the binding of the monoclonal antibody and of serum antibodies to cardiolipin and phosphatidylserine. Additionally patients and contro…
Accuracy of two plasma antibody tests and faecal antigen test for non-invasive detection of H. pylori in middle-aged Caucasian general population sam…
2018
The aim of the study was to assess the accuracy of two plasma Helicobacter pylori (H. pylori) antibody test-systems and a stool antigen test (SAT) system in a general population sample in Latvia.Blood and faecal samples were analysed in healthy individuals (40-64 years), referred for upper gastrointestinal endoscopy according to pilot study protocol within a population-based study investigating gastric cancer prevention strategies (GISTAR pilot study). Antibodies to H. pylori were assessed in plasma by latex-agglutination test and enzyme-linked immunosorbent assay (ELISA). H. pylori antigen in faecal samples was detected by a monoclonal enzyme immunoassay-based SAT. Histological assessment …
Monitoring free serum IgE in severe asthma patients treated with omalizumab
2012
SummaryBackgroundBenefit of treatment with the monoclonal anti-IgE-antibody omalizumab in severe IgE-dependent asthma requires a significant reduction of serum free IgE concentrations. It is unclear if monitoring free serum IgE is clinically meaningful once omalizumab treatment is initiated.MethodsFree IgE and omalizumab serum concentrations were quantified in 22 patients with severe asthma (68% female, 47 ± 11 yrs, mean (±SD) pre-bronchodilator FEV1 62 ± 13%, baseline mean (±SEM) free serum IgE 652 ± 136 ng/ml) treated with omalizumab for 4 months using a Recovery-ELISA.ResultsOmalizumab treatment reduced free serum IgE prior to the second omalizumab injection by 73%, after 16 weeks by 81%…
The applicability of SRTM in [18F]fallypride PET investigations: Impact of scan durations
2011
The high-affinity radioligand [18F]fallypride (FP) is frequently used for quantification of striatal/extrastriatal D2/3 receptors and the receptor occupancies of antipsychotics (APs). Its 110 minutes half-life allows long scan durations. However, the optimum scan duration is a matter of debate. This investigation focuses on scan-duration-related effects on simplified reference tissue model (SRTM) results and the time point of transient equilibrium in a large sample of dynamic FP positron emission tomography (PET) scans. Fifty drug-free and 50 AP-treated subjects underwent FP-PET scans (180 minutes scan duration). The binding potential ( BPND) of the putamen, thalamus, and temporal cortex w…
Heparin-based ELISA reduces background reactivity in virus-like particle-based papillomavirus serology.
2004
The interaction between human papillomavirus (HPV) particles and cell surface heparan sulfate requires intact conformation of the HPV particles. Type-specific HPV serology is currently based on virus-like particles (VLPs) with intact conformation. Presence of incorrectly folded VLPs in VLP preparations is recognized as an important cause of cross-reactivity in HPV serology. Heparin-coated microtitre plates were evaluated for capturing conformationally correct VLPs and improving the type specificity of HPV serology. Hybrid VLPs between HPV16 and HPV11, which had been found to have significant reactivity with children's sera and a batch of HPV18 VLPs that had failed the quality control becaus…
Functional assessment of the quality of human hepatocyte preparations for cell transplantation.
2008
Hepatocyte transplantation is an alternative therapy to orthotopic liver transplantation for the treatment of liver diseases. Good quality freshly isolated or cryopreserved human hepatocytes are needed for clinical transplantation. However, isolation, cryopreservation, and thawing processes can seriously impair hepatocyte viability and functionality. The aim of the present study was to develop a fast and sensitive procedure to estimate the quality of hepatocyte preparations prior to clinical cell infusion. To this end, cell viability, attachment efficiency, and metabolic competence (urea synthesis and drug-metabolizing P450 activities) were selected as objective criteria. Viability of hepat…