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Sandwich Immunoassay (sandwich + immunoassay)
Selected AbstractsCover Picture: Electrophoresis 14'09ELECTROPHORESIS, Issue 14 2009Article first published online: 28 JUL 200 Issue no. 14 is an Emphasis Issue with 9 articles on various aspects of "Proteins and Proteomics" while the remaining 14 articles are arranged into 4 different parts including "Microfluidics and Miniaturization", "Genotyping and Transcriptomics", "Enantioseparations", and "Nanoparticles and Abused Drugs Analyses". Selected articles are: Effective elimination of nucleic acids from bacterial protein samples for optimized blue native polyacrylamide gel electrophoresis ((10.1002/elps.200900026)) 2-D difference in gel electrophoresis combined with Pro-Q Diamond staining: A successful approach for the identification of kinase/phosphatase targets ((10.1002/elps.200800780)) Microvalves actuated sandwich immunoassay on an integrated microfluidic system ((10.1002/elps.200800818)) Chemical gradient-mediated melting curve analysis for genotyping of SNPs ((10.1002/elps.200800729)) [source] Construction of an antibody microarray based on agarose-coated slidesELECTROPHORESIS, Issue 3 2007Lin-Li Lv Abstract The antibody microarray, a high-throughput multiplex immunoassay method, has become a significant tool for quantitative proteomics studies. We describe here the strategies for optimizing the condition of antibody microarray building based on agarose-coated slides. In this study, modified glass slides were robotically printed with capture antibodies against monocyte chemoattractant protein 1 (MCP-1), then dilutions of the cytokine were applied to the arrays, and the protein was detected with biotin-labeled antibody coupled with Cy3-conjugated streptavidin. Thus a protein profiling microarray based on sandwich immunoassay has been established. Various factors in the production of antibody microarrays were analyzed: the capture antibody concentrations, shelf life of the postprinting slides, blocking buffers, and reproducibility of the system. A calibration curve with a correlation coefficient of 0.9995 was established which suggested that the matrix can retain arrayed proteins in near-quantitative fashion. The results revealed high signal uniformity and reproducibility with regard to intra-array (1.3%) and the interarray (8.7%) variation at the capture antibody concentration of 125,µg/mL. Besides, the printed arrays could be stored for at least two months without any apparent change of the performance parameters. [source] Circulating levels of copeptin, a novel biomarker, in lower respiratory tract infectionsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2007B. Müller Abstract Background, Vasopressin has haemodynamic as well as osmoregulatory effects, and reflects the individual stress response. Copeptin is cosynthesized with vasopressin, directly mirroring vasopressin levels, but is more stable in plasma and serum. Both levels are increased in patients with septic shock. Lower respiratory tract infections (LRTI) are a precursor of sepsis. Thus, we investigated circulating levels and the prognostic use of copeptin for the severity and outcome in patients with LRTI. Materials and methods, Five hundred and forty-five consecutive patients with LRTI and 50 healthy controls were evaluated. Serum copeptin levels were measured with a new chemiluminescens sandwich immunoassay. Results, Of the 545 patients, 373 had community-acquired pneumonia (CAP), 60 acute exacerbations of chronic obstructive pulmonary disease (COPD), 59 acute bronchitis, 13 exacerbations of asthma and 40 other final diagnoses. Copeptin levels were significantly higher in patients with LRTI as compared to controls (P < 0·001) with highest levels in patients with CAP. Copeptin levels increased with increasing severity of CAP, as classified by the pneumonia severity index (PSI) (P < 0·001). In patients who died, copeptin levels on admission were significantly higher as compared to levels in survivors [70·0 (28·8,149·0) vs. 24·3 (10·8,43·8) pmol L,1, P < 0·001]. The area under the receiver operating curve (AUC) for survival was 0·75 for copeptin, which was significantly higher as compared to C-reactive protein (AUC 0·61, P = 0·01), leukocyte count (AUC 0·59, P = 0·01) and similar to procalcitonin (AUC 0·68, P = 0·21). Conclusions, Copeptin levels are increased with increasing severity of LRTI namely in patients with CAP and unfavourable outcome. Copeptin levels, as a novel biomarker, might be a useful tool in the risk stratification of patients with LRTI. [source] Circulating levels of pro-atrial natriuretic peptide in lower respiratory tract infectionsJOURNAL OF INTERNAL MEDICINE, Issue 6 2006B. MÜLLER Abstract. Objective., To analyse the mid region of plasma N-terminal pro-atrial natriuretic peptide (MR-proANP) levels in patients with lower respiratory tract infections to evaluate its prognostic use for the severity of disease and outcome. Design., Prospective observational study. Setting., Emergency department of a university hospital. Subjects., A total of 545 consecutive patients with lower respiratory tract infections and 50 healthy controls. Interventions., MR-proANP was measured in serum from all patients using a new sandwich immunoassay. Results., MR-proANP levels (median [IQR], in pmol L,1) were significantly higher in patients with lower respiratory tract infections when compared with controls (138.0 [74.1,279.0] vs. 72.7 [62.5,89.5], P < 0.001), with highest levels in patients with community-acquired pneumonia (CAP). MR-proANP, but not C-reactive protein (CRP) levels, gradually increased with increasing severity of CAP, classified according to the pneumonia severity index (PSI) score (P < 0.001). On admission, MR-proANP levels were significantly higher in nonsurvivors when compared with survivors (293.0 [154.0,633.0] vs. 129.0 [71.4,255.0], P < 0.001). In a receiver operating characteristic (ROC) analysis for the prediction of survival of patients with CAP the area under the ROC curve (AUC) for MR-proANP was 0.69, similar when compared with the PSI (AUC 0.74, P = 0.31), and better when compared with other biomarkers, i.e. procalcitonin (AUC 0.57, P = 0.08), CRP (AUC 0.52, P = 0.02), and leucocyte count (AUC 0.56, P = 0.07). Conclusions., MR-proANP levels are increased in lower respiratory tract infections, especially in CAP. Together with other clinical, radiographic and laboratory findings, MR-proANP levels might be helpful for the risk stratification in CAP. [source] N-terminal atrial natriuretic peptide and left ventricular geometry and function in a population sample of elderly malesJOURNAL OF INTERNAL MEDICINE, Issue 6 2000J. Ärnlöv Abstract. Ärnlöv J, Lind L, Stridsberg M, Andrén B, Lithell H (University of Uppsala, Sweden). N-terminal atrial natriuretic peptide and left ventricular geometry and function in a population sample of elderly males. J Intern Med 2000; 247: 699,708. Objectives. To investigate the relationships between N-terminal atrial natriuretic peptide (N-ANP) and left ventricular geometry and function. Design. A cross-sectional study of a population-based cohort. Setting. Follow-up of a health survey in Uppsala county, Sweden. Subjects., Two hundred and five men aged 70. Main outcome measures. A Delfia sandwich immunoassay was used to measure the plasma levels of N-ANP. M-mode and Doppler echocardiographic examinations were used to measure left ventricular dimensions, mass, geometry and systolic function and to classify the subjects into four groups (normal geometry, concentric remodelling, concentric hypertrophy or eccentric hypertrophy). Left ventricular systolic dysfunction was defined as a left ventricular ejection fraction , 0.40. Results. Plasma levels of N-ANP were significantly increased in subjects with left ventricular dysfunction compared to healthy subjects (702 ± 486, n = 14 vs. 277 ± 201 pmol L,1, n = 118, P < 0.0001), but there was a great overlap between the groups. N-ANP differed significantly between the four different left ventricular geometric groups (P = 0.02) with the highest N-ANP levels in the subjects with left ventricular eccentric hypertrophy (n = 40). However, N-ANP levels were no longer significantly associated with left ventricular geometry when taking the ejection fraction into account. Conclusions. This study showed that N-ANP levels were significantly elevated in subjects with left ventricular dysfunction, as well as in subjects with left ventricular hypertrophy. However, the increase in N-ANP seen in the eccentric hypertrophy group was mainly due to a decreased ejection fraction. [source] Secreted proteome of the murine multipotent hematopoietic progenitor cell line DKmixRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2010Nina Luecke Administration of the multipotent hematopoietic progenitor cell (HPC) line DKmix improved cardiac function after myocardial infarction and accelerated dermal wound healing due to paracrine mechanisms. The aim of this study was to analyse the secreted proteins of DKmix cells in order to identify the responsible paracrine factors and assess their relevance to the wide spectrum of therapeutic effects. A mass spectrometry (MS)-based approach was used to identify secreted proteins of DKmix cells. Serum free culture supernatants of DKmix-conditioned medium were collected and the proteins present were separated, digested by trypsin and the resulting peptides were then analyzed by matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) MS. Overall 95 different proteins were identified. Among them, secretory proteins galectin-3 and gelsolin were identified. These proteins are known to stimulate cell migration and influence wound healing and cardiac remodelling. The remaining proteins originate from intracellular compartments like cytoplasm (69%), nucleus (12%), mitochondria (4%), and cytoplasmic membrane (3%) indicating permeable or leaky DKmix cells in the conditioned medium. Additionally, a sandwich immunoassay was used to detect and quantify cytokines and chemokines. Interleukin-6 (IL-6), interleukin-13 (IL-13), monocyte-chemoattractant protein-1 (MCP-1), monocyte-chemoattractant protein-3 (MCP-3), monocyte-chemoattractant protein-1, (MIP-1,) and monocyte-chemoattractant protein-1, (MIP-1,) were detected in low concentrations. This study identified a subset of proteins present in the DKmix-conditioned medium that act as paracrine modulators of tissue repair. Moreover, it suggests that DKmix-derived conditioned medium might have therapeutic potency by promoting tissue regeneration. Copyright © 2010 John Wiley & Sons, Ltd. [source] Copeptin: A novel, independent prognostic marker in patients with ischemic stroke,ANNALS OF NEUROLOGY, Issue 6 2009Mira Katan MD Objective Early prediction of outcome in patients with ischemic stroke is important. Vasopressin is a stress hormone. Its production rate is mirrored in circulating levels of copeptin, a fragment of provasopressin. We evaluated the prognostic value of copeptin in acute stroke patients. Methods In a prospective observational study, copeptin was measured using a new sandwich immunoassay on admission in plasma of 362 consecutive patients with an acute ischemic stroke. The prognostic value of copeptin to predict the functional outcome (defined as a modified Rankin Scale score of ,2 or ,3), mortality within 90 days, was compared with the National Institutes of Health Stroke Scale score and with other known outcome predictors. Results Patients with an unfavorable outcomes and nonsurvivors had significantly increased copeptin levels on admission (p <0.0001 and p <0.0001). Receiver operating characteristics to predict functional outcome and mortality demonstrated areas under the curve of copeptin of 0.73 (95% confidence interval [CI], 0.67,0.78) and 0.82 (95% CI, 0.76,0.89), which was comparable with the National Institutes of Health Stroke Scale score but superior to C-reactive protein and glucose (p <0.01). In multivariate logistic regression analysis, copeptin was an independent predictor of functional outcome and mortality, and improved the prognostic accuracy of the National Institutes of Health Stroke Scale to predict functional outcome (combined areas under the curve, 0.79; 95% CI, 0.74,0.84; p <0.01) and mortality (combined areas under the curve, 0.89; 95% CI, 0.84,0.94; p <0.01). Interpretation Copeptin is a novel, independent prognostic marker improving currently used risk stratification of stroke patients. Ann Neurol 2009;66:799,808 [source] Serum chemokine profile in patients with bullous pemphigoidBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2007H. Nakashima Summary Background, Bullous pemphigoid (BP) is an autoimmune inflammatory disease causing blister formation at the dermoepidermal junction. Cutaneous infiltration of activated CD4+ T cells and eosinophils is an early event in blister formation during the disease process, suggesting that the trafficking of circulating leucocytes through the sites of inflammation is crucial in the pathogenesis of the disease. While the accumulated evidence suggests that some cytokines are involved in the pathogenesis, there have been few reports about serum chemokine profiles in patients with BP. Objectives, To determine serum profiles of various chemokines and their clinical association in patients with BP. Methods, Concentrations of 10 chemokines , interferon (IFN)- , -inducible protein-10 (IP-10), monokine induced by IFN- , (MIG), macrophage inflammatory protein (MIP)-1,, MIP-1,, RANTES, eotaxin, monocyte chemoattractant protein (MCP)-1, MCP-2, MCP-3 and growth-regulated oncogene- ,, were measured in serum samples from 38 patients with BP, 16 with pemphigus vulgaris (PV) and 17 normal controls using a sandwich immunoassay-based multiplex protein array system. Results, While there was no significant increase in any serum chemokine levels in patients with PV, serum levels of IP-10 and MCP-1 were significantly increased in patients with BP compared with healthy controls. Furthermore, serum levels of IP-10, MIG, MCP-1 and eotaxin in patients with BP increased significantly with disease severity as determined by the area affected. Conclusions, These observations suggest that an elaborately orchestrated network of chemokines, especially MCP-1 and IP-10, contributes to the pathomechanism of BP. [source] | ||||||||||