No abstract

Background. Amino acids are the building blocks of proteins. In case of insulin resistance, which is typical for type 2 diabetes mellitus (T2DM), proteolysis is increased and protein synthesis is decreased; therefore, we can observe changes in the levels of amino acids in diabetics vs. non-diabetics. Objectives. The aim of this study was to find differences in the levels of selected amino acids between patients with diabetes (type 2) and a control group. Material and Methods. Amino acids were derivatized with naphthalene-2,3-dicarboxaldehyde in the presence of potassium cyanide to form fluorescent 1-cyanobenz(f)isoindole product. Amino acids derivatives were measured using a high-performance liquid chromatography with fluorescence detection. The serum levels of glucose were determined using an automatic biochemistry analyzer, glycated hemoglobin HbA1c was measured by cation exchange chromatography. Results. A total of 19 serum amino acids in T2DM patients and non-diabetics were measured. There were 9 amino acids, which were significantly different in these groups (p < 0.05). Significantly decreased levels of arginine, asparagine, glycine, serine, threonine and significantly increased levels of alanine, isoleucine, leucine, valine in diabetics were found. Conclusions. Significant difference in metabolism of amino acids between diabetics and non-diabetics were observed. The altered levels of amino acids in diabetic patients could be a suitable predictor of diabetes (Adv Clin Exp Med 2015, 24, 3, 447-451).

A method is described here for the simultaneous determination of retinol,α-tocopherol, lycopene, andβ-carotene in human plasma. The effectiveness of various protein precipitants and extraction solvents was tested. After adequate sample preparation, the samples were injected directly into the HPLC system. The separation was realized on an analytical reversed-phase column with a UV-Vis detection. The analytical performance of this method was satisfactory. The intraassay and interassay coefficients of variation were below 10%. The recoveries were as follows: 97.0% (CV 2.4%) for retinol, 94.6% (CV 1.7%) forα-tocopherol, 91.9% (CV 3.6%) for lycopene, and 93.9% (CV 4.2%) forβ-carotene. The levels of selected fat-soluble vitamins in plasma of patients with cardiovascular disease were measured and discussed.

Oxidative stress has been proposed as one of the potential causes for infertility in men. Retinol and α-tocopherol have an important role in the spermatozoa defences against oxidative stress. A method is described here for the simultaneous determination of retinol and α-tocopherol in human seminal plasma with a suitable sample preparation procedure to prevent retinol and α-tocopherol degradation. After adequate sample preparation, the samples were determined by reversed-phase column chromatography with UV detection. The analytical performance of this method was satisfactory. The intra-assay and inter-assay coefficients of variation were below 10%. The recoveries were as follows: 90.7% (CV 8.1%) for retinol and 98.2% (CV 4.8%) for α-tocopherol. No significant differences in both retinol and α-tocopherol concentration between the smokers and nonsmokers (15 ± 7 nm and 1.86 ± 0.29 μm versus 15 ± 6 nm and 1.93 ± 0.45 μm) were found. A selective high-performance liquid chromatography method for the determination of retinol and α-tocopherol in human seminal plasma was developed.

The aim of this study was to find some relationship between amino acid metabolism and the embryo morphokinetic parameters studied via time-lapse analysis. Study included 48 human embryo samples and their culture media. Two groups of embryos were identified: embryos reached the 8-cell stage on day 3 (n=34) and embryos failed to develop at any point during the incubation (n=14). Amino acids levels were measured on day 3 of embryo development; using time-lapse analysis, the precise timing of embryo cleavage, synchrony of division, grade of fragmentation etc. were established. No statistically significant differences between dividing and arresting embryos were observed in terms of amino acids production/consumption and turnover. Amino acids which were part of the culture medium did not exhibit any statistically significant correlation with kinetic parameters with the exception of the grade of fragmentation on day 3; there were negative correlation with glutamate, and positive with glutamine, glycine and taurine. In some dividing and in some arresting embryos appeared new amino acids which strongly correlated with each other, with methionine, but not with any other amino acid that is a regular part of the culture medium.