1,721,074 research outputs found
Plasma L-ergothioneine measurement by high-performance liquid chromatography and capillary electrophoresis after a pre-column derivatization with 5-iodoacetamidofluorescein (5-IAF) and fluorescence detection
No full textTwo sensitive and reproducible capillary electrophoresis and high-performance liquid chromatography-fluorescence procedures were established for quantitative determination of L-egothioneine in plasma. After derivatization of L-ergothioneine with 5-iodoacetamidofluorescein, the separation was carried out by HPLC on an ODS-2 C-18 sperisorb column by using a linear gradient elution and by HPCE on an uncoated fused silica capillary, 50 µm id, and 60 cm length. The methods were validated and found to be linear in the range of 0.3 to 10 µmol/l. The limit of quantification was 0.27 µmol/l for HPCE and 0.15 µmol/l for HPLC. The variations for intra- and inter-assay precision were around 6 RSD%, and the mean recovery accuracy close to 100% (96.11%)
Determination of protein-incorporated methylated arginine reference values in healthy subjects whole blood and evaluation of factors affecting protein methylation
No full textSodium glycylglycine as effective electrolyte run buffer for ascorbic and uric acid separation by CZE: a comparison with two other CE assays
No full textReverse injection capillary electrophoresis UV detection for serotonin quantification in human whole blood
No full textWe describe the first capillary electrophoresis UV detection method to measure serotonin in human whole blood (WB). Procedural parameters such as concentration and pH of run buffer and injection mode were investigated. The reverse injection allows to decrease the analysis time by injecting samples at the outlet end of the silica capillary close to the detection window, so reducing the migration distance. Thus, when a capillary with an effective length of 10 cm and a 400 mmol/L Tris phosphate as background electrolyte at pH 3.25 was used, the migration time of the serotonin peak was 2.6 min. These conditions gave a good reproducibility of migration times (CV, 0.77%) and peak areas (CV, 2.44%). Intra- and inter-assay CV were 3.85% and 7.32%, respectively, and the analytical recovery was between 96.8% and 99.4%
Simultaneous determination of citrulline and arginine in human blood plasma by capillary electrophoresis with ultraviolet absorption detection
No full textA new capillary electrophoresis method to measure human blood plasma arginine and
citrulline levels in a single run without derivatization was established. After adding homoarginine
as internal standard, plasma proteins were removed by a 90:10 v/v acetonitrile/ammonia
mixture. Arginine and citrulline were detected by an ultraviolet detector at
190 nm and separated in 11.65 and 20.43 min, respectively, by using a 75 mmol/L Tris
phosphate solution at pH 1.2 as a background electrolyte. Limits of detection were 0.8 and
5 mol/L for arginine and citrulline, respectively. Precision tests indicated a good repeatability
of migration times and of peak area both for citrulline (CV% = 0.82 and 3.19) and
arginine (CV% = 0.65 and 2.79). The CV% for intra- and interassay tests were, respectively,
1.84 and 3.23 for citrulline and 1.25 and 1.50 for arginine. Mean recovery was 101.5 and
98.5% for citrulline and arginine, respectively. The performance of the developed method
was assessed by measuring plasma arginine levels in 52 subjects and the data were compared
with those obtained by our previous assay. The new method was then applied to assess
plasma citrulline and arginine in ten chronic kidney disease patients under hypolipidemic
therapy with statin
Serum CK-MB, COVID-19 severity and mortality: An updated systematic review and meta-analysis with meta-regression
No full textObjectives: We conducted a systematic review and meta-analysis with meta-regression of creatine kinase-MB (CK-MB), a biomarker of myocardial injury, in COVID-19 patients. Methods: We searched PubMed, Web of Science and Scopus, for studies published between January 2020 and January 2021 that reported CK-MB, COVID-19 severity and mortality (PROSPERO registration number: CRD42021239657). Results: Fifty-five studies in 11,791 COVID-19 patients were included in the meta-analysis. The pooled results showed that CK-MB concentrations were significantly higher in patients with high disease severity or non-survivor status than patients with low severity or survivor status (standardized mean difference, SMD, 0.81, 95% CI 0.61 to 1.01, p<0.001). The rate of patients with CK-MB values above the normal range was also significantly higher in the former than the latter (60/350 vs 98/1,780; RR = 2.84, 95%CI 1.89 to 4.27, p<0.001; I2 = 19.9, p = 0.254). Extreme between-study heterogeneity was observed (I2 = 93.4%, p<0.001). Sensitivity analysis, performed by sequentially removing each study and re-assessing the pooled estimates, showed that the magnitude and direction of the effect size was not modified (effect size range, 0.77 to 0.84). Begg's (p = 0.50) and Egger's (p = 0.86) t-tests did not show publication bias. In meta-regression analysis, the SMD was significantly and positively associated with the white blood count, aspartate aminotransferase, myoglobin, troponin, brain natriuretic peptide, lactate dehydrogenase, and D-dimer. Conclusions: Higher CK-MB concentrations were significantly associated with severe disease and mortality in COVID-19 patients. This biomarker of myocardial injury might be useful for risk stratification in this group
Optimization of ascorbic and uric acid separation in human plasma by free zone capillary electrophoresis ultraviolet detection
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