Lipidic profiles of patients starting peritoneal dialysis suggest an increased cardiovascular risk beyond classical dyslipidemia biomarkers.

Patients on peritoneal dialysis (PD) have an increased risk of cardiovascular disease (CVD) and an atherogenic lipid profile generated by exposure to high glucose dialysis solutions. In the general population, the reduction of classic lipids biomarkers is associated with improved clinical outcomes; however, the same results have not been seen in PD population, a lack of data this study aims to fulfill. Single-center prospective observational study of a cohort of CKD patients who started renal replacement therapy with continuous ambulatory peritoneal dialysis. The differences in the lipid profile and analytical variables before and 6 months after the start of peritoneal dialysis were analyzed. Samples were analyzed on an Ultra-Performance Liquid Chromatography system. Thirty-nine patients were enrolled in this study. Their mean age was 57.9 ± 16.3 years. A total of 157 endogenous lipid species of 11 lipid subclasses were identified. There were significant increases in total free fatty acids (p < 0.05), diacylglycerides (p < 0.01), triacylglycerides, (p < 0.01), phosphatidylcholines (p < 0.01), phosphatidylethanolamines (p < 0.01), ceramides (p < 0.01), sphingomyelins (p < 0.01), and cholesterol esters (p < 0.01) from baseline to 6 months. However, there were no differences in the classical lipid markers, neither lysophosphatidylcholines, monoacylglycerides, and sphingosine levels. 6 months after the start of the technique, PD patients present changes in the lipidomic profile beyond the classic markers of dyslipidemia.

Effect of storage and preservation of milk samples on the response of microbial inhibitor tests.

The aim of this study was to evaluate the effect of storage time (4 °C) on milk samples and the use of azidiol as preservative on the results of microbial inhibitor tests used to detect antimicrobials in milk. For this purpose, 16 milk bulk samples divided into two aliquots, preservative-free and with azidiol, spiked with 12 concentrations of amoxicillin, ampicillin, penicillin G and oxytetracycline, were used. The milk samples were analysed using the BRT MRL, Delvotest MCS Accelerator and Eclipse 100 at 0, 24, 48 and 72 h stored at 4 °C. The logistic regression model was applied to study the effect of storage time (ST), preservative (P) and their interaction (ST×P). At a concentration equivalent to the Detection Limit (DL), the positive results of microbial inhibitor tests do not remain stable during storage time. These results are more reproducible if samples are stored with a preservative. At Maximum Residue Limits (MRLs) concentration microbial inhibitor tests can detect penicillin for up to 72 h of storage. For oxytetracycline, the BRT MRL and Delvotest MCS tests presents DL exceeding the MRL, therefore they are not sensitivity to this tetracycline (0% positive results). By contrast Eclipse 100, whose DL is lower than the MRL, gave 100% positive results during the 72 h storage period. It can be concluded that it would be convenient to store milk samples with azidiol at 4 °C and to carry out analyses within the first 48 h since milk sampling.