A NEW CAPILLARY ZONE ELECTROPHORESIS METHOD FOR THE SCREENING OF CONGENITAL DISORDERS OF GLYCOSYLATION (CDG)

2009 ◽  
Vol 32 (6S) ◽  
pp. 7
Author(s):  
F Parente ◽  
N Ah Mew ◽  
J Jaeken ◽  
B M Gilfix

Background: The Congenital Disorders of Glycosylation (CDG) are an expanding group of metabolic diseases with a broad clinical presentation. We sought to validate a new Capillary Zone Electrophoresis (CZE) method (Sebia CAPILLARYS™ CDT) to screen for CDG. Methods: We analyzed 119 serum samples from children of varying ages and of both sexes to establish a reference range of transferrin glycoforms including CDT (Carbohydrate Deficient Transferrin). We then studied serums from 8 known CDG patients and compared the CZE results to the isoelectric focusing (IEF) profiles. We also analyzed serums after extraction from spotted Guthrie cards. Results: The mean (SD) percentage of transferrin glycoforms is 18.5 (4.4), 78.5 (4.2), 2.5 (1.3) and 0.6 (0.3) for penta-, tetra-, trisialotransferrin and CDT, respectively. There is no statistically significant difference between the different age groups analyzed (0-5, 6-11, 12-15, 16-18, and > 18 years) or between sexes. We observed a good correlation between the CZE and IEF profiles with both fresh serum and serum extracted from Guthrie cards. Conclusions: The Sebia CAPILLARYS™ CDT system is a simple and reliable method to screen for CDG in pediatric and adult patients with an unexplained clinical syndrome, particularly when the nervous system is involved.

2004 ◽  
Vol 50 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Hubert A Carchon ◽  
Roland Chevigné ◽  
Jean-Bernard Falmagne ◽  
Jaak Jaeken

Abstract Background: Congenital disorders of glycosylation (CDG) are usually diagnosed by isoelectric focusing (IEF) of serum transferrin (Tf). The aim of this study was to evaluate capillary zone electrophoresis (CZE) as a diagnostic alternative to IEF. Methods: We performed 792 CZE analyses of Tf, using the CEofixTM-CDT (carbohydrate-deficient transferrin) assay. Peak identification was based on relative migration times (RMTs) to reduce migration variability. Results: Tf profiles comprised three main groups (A–C). Groups A and B were characterized by one or two dominant tetrasialo-Tf peaks, whereas group C showed a widely variable Tf isoform composition. Group A was composed of four subgroups: a major group with a typical Tf profile (considered as reference group), two minor groups with decreased or moderately increased trisialo-Tf isoform, and a group showing the presence of unknown compounds with RMTs similar to mono- and disialo-Tf. However, these compounds were absent on IEF. Group C contained all profiles from patients with confirmed as well as putative CDG. From the reference group, 99% confidence intervals were calculated for the RMTs of the Tf isoforms, and percentiles representing the Tf isoform distributions were defined. Conclusions: All patients with abnormal IEF results and confirmed CDG were identified by CZE; thus, this method can be used as a diagnostic alternative to IEF in a manner suitable for automation. Because whole serum is analyzed, it should be kept in mind that CZE profiles can show substances other than Tf.


2012 ◽  
Vol 7 ◽  
pp. ACI.S9940 ◽  
Author(s):  
Mohamed Salim ◽  
Nahed El-Enany ◽  
Fathallah Belal ◽  
Mohamed Walash ◽  
Gabor Patonay

A novel, quick, reliable and simple capillary zone electrophoresis CZE method was developed and validated for the simultaneous determination of sitagliptin (SG) and metformin (MF) in pharmaceutical preparations. Separation was carried out in fused silica capillary (50.0 cm total length and 43.0 cm effective length, 49 μm i.d.) by applying a potential of 15 KV (positive polarity) and a running buffer containing 60 mM phosphate buffer at pH 4.0 with UV detection at 203 nm. The samples were injected hydrodynamically for 3 s at 0.5 psi and the temperature of the capillary cartridge was kept at 25 °C. Phenformin was used as internal standard (IS). The method was suitably validated with respect to specificity, linearity, limit of detection and quantitation, accuracy, precision, and robustness. The method showed good linearity in the ranges of 10-100 μg/mL and 50-500 μg/mL with limits of detection of 0.49, 2.11 μm/mL and limits of quantification of 1.48, 6.39 μg/mL for SG and MF, respectively. The proposed method was successfully applied for the analysis of the studied drugs in their synthetic mixtures and co-formulated tablets without interfering peaks due to the excipients present in the pharmaceutical tablets. The method was further extended to the in-vitro determination of the two drugs in spiked human plasma. The estimated amounts of SG/MF were almost identical with the certified values, and their percentage relative standard deviation values (% R.S.D.) were found to be ≤1.50% (n = 3). The results were compared to a reference method reported in the literature and no significant difference was found statistically.


2009 ◽  
Vol 1216 (15) ◽  
pp. 3349-3352 ◽  
Author(s):  
Jennifer P. Pascali ◽  
Eloisa Liotta ◽  
Rossella Gottardo ◽  
Federica Bortolotti ◽  
Franco Tagliaro

1990 ◽  
Vol 36 (3) ◽  
pp. 435-440 ◽  
Author(s):  
A C Schoots ◽  
T P Verheggen ◽  
P M De Vries ◽  
F M Everaerts

Abstract Organic anions accumulated in blood serum of patients with chronic renal failure were separated by a novel technique: closed-system capillary zone electrophoresis (CZE) in a pH6 carrier-electrolyte system. Hippuric acid (HA), p-hydroxyhippuric acid, and uric acid were identified by their co-elution with standards prepared in ultrafiltered normal serum and by comparison with the corresponding ultraviolet-detected peaks positively identified in the HPLC analyses. Analysis time for the entire profile is 8 min. Repeatabilities (CVs) of CZE migration times and peak areas of the three acids in serum samples were about 0.7% and 6%, respectively. We quantified HA in 10 ultrafiltered uremic serum samples and compared results with those by a previously described HPLC procedure. The very good agreement further supports the identification of hippuric acid. Accuracy and precision of the CZE method were similar to those for the HPLC gradient-elution method, but analysis time for HA (8 min) is much less than by HPLC (90 min). Our technique is very suitable for selective, rapid analysis for (ultraviolet-absorbing) anionic constituents in ultrafiltered uremic serum, without any sample pretreatment.


2012 ◽  
Vol 10 (6) ◽  
pp. 1808-1816 ◽  
Author(s):  
Luiza Marcellos ◽  
Adriana Faria ◽  
Marcus Souza ◽  
Mariana Almeida ◽  
Guilherme Sabin ◽  
...  

AbstractThe development and optimization of a novel UV spectrophotometric methodology was proposed for simultaneous analysis of ethambutol (ETB), isoniazid (ISO), rifampicin (RIF) and pyrazinamide (PYR), using multivariate calibration based on the partial least squares method (PLS). The methodology was successfully applied for analysis of four-drug fixed dose combination (4-FDC) tablets used for tuberculosis treatment. A 34 Box-Behnken design, with triplicate in central point, was used for sample preparation in the calibration step. In the present case, nine latent variables were chosen for the model development that presented the smallest RMSECV and explain 98.76% of data variance in Y block (concentrations of ETB ISO, RIF and PYR) and 99.93% of data variance in X block (spectral data). PLS models for ETB, ISO, RIF and PYR presented RMSEP and R2 values of 0.23 mg L−1 and 0.971; 0.14 mg L−1 and 0.731; 0.11 mg L−1 and 0.990 and 0.57 mg L−1 and 0.972, respectively. A validation step was performed based on the comparison between the UV spectrophotometric proposed methodology and capillary zone electrophoresis (CZE) in 4-FDC real samples and no significant difference was found between two methodologies at 95% of confidence level.


2013 ◽  
Vol 11 (8) ◽  
pp. 1286-1296 ◽  
Author(s):  
Renata Jesus Coelho Castro ◽  
Fausto Sobrinho ◽  
Marco Sundfeld da Gama ◽  
Patrícia Castro Barra ◽  
Rosemar Antoniassi ◽  
...  

AbstractAn alternative method for extraction optimization of C18:2 n-6 and C18:3 n-3, the main precursors for the synthesis of conjugated linoleic acid (CLA), in Brachiaria ruzizienses forages was proposed. Three methods of lipid extraction were tested: 1. Hara & Radin, 2. Micro Folch and 3. Bligh & Dyer. The preliminary test showed the Hara & Radin method as the most promising procedure. Then, a 33 Box Behnken design with triplicate in the central point was applied in Hara & Radin method in order to optimize the extraction procedure. The optimization extraction was monitored by quantification of C18:2 n-6 and C18:3 n-3 through capillary zone electrophoresis (CZE). The results obtained by CZE were compared to gas chromatography (AOCS official method) in real samples using the paired t-test. No significant difference between methods was found within a 95% confidence interval (p-value= 0.937). The alternative CZE method for Brachiaria ruzizienses forages analysis has some advantages in comparison with official GC method such as, short analysis time (10 min), no derivatization step for sample preparation, absence of specific separation columns, lower analytical cost and high throughput.


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