Impedimetric lectin biosensors capable of recognizing two different carbohydrates (galactose and sialic acid) in glycans attached to antibodies isolated from human serum were prepared. The first step entailed the modification of a gold surface by a self-assembled monolayer (SAM) deposited from a solution containing a carboxybetaine-terminated thiol applied to the subsequent covalent immobilization of lectins and to resist nonspecific protein adsorption. In the next step, Sambucus nigra agglutinin (SNA) or Ricinus communis agglutinin (RCA) was covalently attached to the SAM, and the whole process of building a bioreceptive layer was optimized and characterized using a diverse range of techniques including electrochemical impedance spectroscopy, cyclic voltammetry, quartz crystal microbalance, contact angle measurements, zeta-potential assays, X-ray photoelectron spectroscopy, and atomic force microscopy. In addition, the application of the SNA-based lectin biosensor in the glycoprofiling of antibodies isolated from the human sera of healthy individuals and of patients suffering from rheumatoid arthritis (RA) was successfully validated using an SNA-based lectin microarray. The results showed that the SNA lectin, in particular, is capable of discriminating between the antibodies isolated from healthy individuals and those from RA patients based on changes in the amount of sialic acid present in the antibodies. In addition, the results obtained by the application of RCA and SNA biosensors indicate that the abundance of galactose and sialic acid in antibodies isolated from healthy individuals is age-related.
Autonomic dysfunction is commonly detected in patients with multiple sclerosis (MS). However, data evaluating autonomic nervous system function in early MS are limited. Present study investigates response to two different stressors in newly diagnosed MS patients, looking for the signs of autonomic dysfunction at the beginning of the disease. We examined 19 MS patients and 19 age, sex, and body mass index matched healthy controls. MS patients were newly diagnosed, untreated, and with low expanded disability status scale (EDSS) values [median 1.0 (interquartile range 1.0-1.5)]. Two stressors were used to evaluate the response of autonomic nervous system: Stroop word-color interference mental stress test and orthostasis. Plasma levels of epinephrine and norepinephrine, blood pressure (BP), and heart rate variability (HRV) parameters were evaluated. At the end of Stroop test MS patients had lower systolic BP (121 ± 15 vs. 132 ± 17 mmHg, p = 0.044), lower heart rate (79 ± 9 vs. 88 ± 16 1/min, p = 0.041), and lower epinephrine increment (10 ± 22 vs. 30 ± 38 pg/ml; p = 0.049) compared to healthy controls. Norepinephrine response was unaffected in MS, however, with lower norepinephrine levels during the test (p = 0.036). HRV parameters were similar in both groups. No differences in BP, heart rate, catecholamines, and HRV parameters between groups during orthostatic testing were found. We found slightly diminished sympathetic response to mental stress test, but unchanged response to orthostasis, in newly diagnosed untreated MS patients. The results suggest that autonomic dysfunction in MS is connected with more developed disease.
Our findings suggest that complex interactions exist between genotype and adrenal androgen hypofunction in RA.
Background Lower levels of dehydroepiandrosterone sulphate (DHEAS) were found in chronic inflammatory diseases such as rheumatoid arthritis (RA), however, mechanisms for this decrease remains unclear. Recently, several genes has been found to be associated with lower DHEAS levels [1]. Objectives The aim of our study was to analyze frequency of selected single nucleotide polymorphisms (SNPs) known to be associated with low DHEAS in RA patients and their impact on DHEAS levels during disease. Methods 1034 participants (438 RA, 596 controls) were analyzed for SNPs in genes ZKSCAN5 (rs11761528), SULT2A1 (rs2637125), HHEX (rs2497306) and ARPC1A (rs740160) by real-time PCR genotyping assay. Serum DHEAS concentration was measured in 156 RA patients and 102 healthy controls by ELISA. Results RA patients had significantly lower DHEAS than controls (age-adjusted), in female (p<0.001) as well as in male subgroup (p=0.013). The frequency of DHEAS-related SNPs were similar in RA and control groups. In RA female patients linear regression model adjusted for age and glucocorticoid treatment, showed significant effect of risk alleles in SULT2A1 (p<0.05) and HHEX (p<0.05) genes to lowering serum DHEAS levels. Conclusions Complex interactions exist between DHEAS-associated genotypes and adrenal androgen hypofunction in RA suggesting a significant contribution to adrenal androgen hypofunction in RA. References Zhai G et al. Eight common genetic variants associated with serum DHEAS levels suggest a key role in ageing mechanisms. PLoS Genet. 2011; 7(4):e1002025. Acknowledgements Study was supported by VEGA 2/0018/12 Disclosure of Interest : None declared DOI 10.1136/annrheumdis-2014-eular.5779
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.