Rabbit Anti-Arachidonic Acid (AA) Polyclonal Antibody

Objective Amino acids (AA) and their derivatives play an integral role in the synthesis of structural and regulatory elements in human organisms and therefore pathologies such as systemic sclerosis that may alter the blood pattern of these compounds. This study aimed to evaluate changes in plasma concentrations of amino acid-related metabolites in systemic sclerosis in a search for potential biomarkers and mechanisms of the disease. Methods Plasma samples from 42 patients diagnosed with systemic sclerosis (SSc) according to the 2013 American College of Rheumatology and European League Against Rheumatism ACR/EULAR classification criteria were compared to 27 matched healthy controls. Liquid chromatography/mass spectrometry was applied for the analysis of 36 amino acid-related metabolites. Results The analysis of plasma AA metabolite patterns revealed the number of changes including an increase (20%) in concentrations of NO synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) in SSc vs. healthy subjects. Furthermore, SSc patients had higher glutamine, proline, betaine, 1-methylhistidine, and methylnicotinamide levels, while the concentration of tryptophan was lower. The specific metabolic pattern was identified for several aspects of disease presentation. Most interestingly NOS inhibitor L-NAME was elevated in patients with diffuse systemic sclerosis or telangiectasia. Conclusions These results provide further evidence for the involvement of endothelium-dependent pathways in the mechanisms and presentation of SSc. Endothelial dysfunction biomarkers may be useful in the assessment of presentation and prognosis in SSc.

A multiproduct approach toward method development is presented for a fast and reliable analysis of the eight most important cholesterol-lowering drugs via ultra-high-performance supercritical fluid chromatography. A two-step approach based on design of experiments was applied: (1) selection of the stationary phase, organic modifier, and diluent in the mobile phase through a multilevel categorical design and (2) optimization of the elution strength by varying the pressure, temperature, and gradient using a central composite design. Finally, the flow rate was adjusted. The first design selected UPC(2)Torus 1-AA as the column, ethanol:water as the organic modifier, and acetonitrile:ethanol 3:2 v/v as the diluent. The results led to a pressure, column temperature, and gradient elution of 14.83 MPa, 42 degrees C, and 5-15.5% of ethanol:water in CO2, respectively. The flow rate was set at 1.8 mL/min, providing a total analysis time of 4 min. This multiproduct method was validated and applied to 11 different commercial products available in the Brazilian market, and it was found to be accurate, withr> 0.990, recoveries between 95 and 105%, and precision not higher than 5.4%. Therefore, this method was shown to be a greener alternative for the analysis of these pharmaceuticals.