Validation of a solid phase extraction-high performance liquid chromatographic method for the determination of eprosartan in human plasma.

In this work, a solid phase extraction-reversed phase high performance liquid chromatographic (SPE-RP-HPLC) method with photometric detection for monitoring the antihypertensive drug eprosartan has been validated in order to assure good quantitation of eprosartan in plasma samples obtained from patients under cardiovascular treatment. This analytical method was developed by using experimental design and quantitation was accomplished with the internal standard method. No interferences were observed from endogenous compounds of plasma and other drugs which are commonly co-administered in elderly patients. The recoveries of eprosartan from plasma samples, measured at three levels of the linear concentration range (150-4000 ng/mL) were found to be between 93.4 and 102.8%. The intraday and interday precision and accuracy (measured by relative standard deviation, RSD, and relative error, RE, respectively) were always lower than 13% (RSD) and 4% (RE). Stability studies showed that eprosartan stock solutions are stable for at least 3 months when stored at 8 degrees C and plasma samples containing the drug were stable at least during the whole analytical method.

Angiotomografía renal en el donante vivo y su correlación con la ablación quirúrgica / Computed tomography renal angiography of living donors and its correlation with surgery

Objetivos: Determinar la precisión de la angiotomografía renal (ATR) en la evaluación del sistema arterial y las variantes anatómicas en el donante vivo, con la correlación con su ablación quirúrgica. Materiales y métodos: Se evaluaron retrospectivamente los pacientes sometidos a nefrectomía laparoscópica como donantes vivos renales y sus ATR, entre 2014 y 2016 en nuestra Institución. Se utilizó análisis estadístico descriptivo para presentar los resultados. En la ATR se evaluaron: número de arterias renales principales, presencia y número de arterias polares y alteraciones del calibre de la arteria renal. Resultados: Se incluyeron 21 pacientes sometidos a nefrectomía laparoscópica como donantes vivos, 10 mujeres y 11 hombres (entre 23 y 61 años). En todos los casos se realizó la ablación del riñón izquierdo. De los 21 pacientes analizados, 15 no presentaron variantes anatómicas ni alteraciones del calibre en la ATR (una arteria renal principal, sin polares). Estos mismos hallazgos se certificaron en la ablación. En un caso, la ATR observó doble arteria renal principal con el mismo hallazgo quirúrgico; y en tres casos la ATR reconoció una única arteria polar, las cuales se corroboraron en la ablación. En estos 19 casos se demostró correlación entre la ATR y la ablación, con una precisión del 90,4% En los 2 casos restantes, hubo discrepancias. Conclusión: El conocimiento detallado del sistema arterial es necesario para la planificación quirúrgica de la nefrectomía laparoscópica del donante vivo renal. La angiotomografía renal constituye el método de elección para su evaluación, demostrando muy buena correlación entre sus hallazgos y los de la ablación.

Objective: To determine the accuracy of computed tomography renal angiography (CTRA) in the assessment and diagnosis of arterial vascular anatomy of the kidney and its variations in living kidney donors, with its correlation in harvesting kidneys. Materials and methods: Patients who had undergone laparoscopic nephrectomy as living kidney donors and their CTRA were retrospectively evaluated between 2014 and 2016 in our institution. Results are presented using statistical descriptive analysis. The following were assessed in the CTRA report: number of main renal arteries, presence and number of accessory polar arteries, and anomalies related to renal artery calibre. Results: Of the 21 patients that had undergone laparoscopic nephrectomy as living donors, there were 10 female and 11 male donors (age range 23 - 61 years). Renal harvesting included left kidney in all cases. In 15 cases, no anatomical variations or arterial renal dilations were found in computed tomography renal angiography (CTRA): (one main renal artery, without accessories arteries). The same findings were certified during the surgery. In one case CTRA showed a double renal artery, and the same finding occurred in the surgical harvesting; and three cases in which one single polar accessory artery was certified at surgery. An overall accuracy of 90.4% for CTRA was obtained in 19 cases. In the remaining 2 cases, a discrepancy was found. Conclusion: Detailed knowledge of the renal arterial anatomy is important for the preoperative evaluation of the laparoscopic nephrectomy in living renal donors. Computed tomography renal angiography (CTRA) is the technique of choice for these patients, as it demonstrates a high correlation between tomography findings and surgery harvesting.

Development of a solid phase extraction procedure for HPLC-DAD determination of several angiotensin II receptor antagonists in human urine using mixture design.

The optimisation of a solid phase extraction procedure involves several variables whose influence has been widely studied. However, in most cases, only process variables are taken into account. In this work, the influence of those process variables together with the fact of using mixtures of solvents during the elution step of the solid phase extraction of four angiotensin II receptor antagonist drugs has been studied. Since the influence on the extraction efficiency of several process variables were simultaneously tested, a D-optimal design was constructed. The composition of the elution solvent (a mixture of methanol, acetonitrile, ethanol and acetone at different proportions from 0 to 100% each solvent), the percentage and pH of the buffer solution added to the urine samples at the beginning of the extraction procedure; the percentage of the organic component and the volume of the washing solution, the drying time and the volume of the elution solvent were the studied variables. The chromatographic separation was carried out by gradient elution mode with 0.026% trifluoroacetic acid (TFA) in the organic phase and 0.031% TFA in the aqueous phase using an Atlantis dC18, 100mmx3.9mm I.D. chromatographic column at a flow rate of 1mL/min and a column temperature of 35+/-0.2 degrees C. For detection a diode array detector set at 232nm was used. The extraction procedure for spiked human urine samples was developed using C8 cartridges, phosphate buffer pH 6.8 as conditioning agent, a drying step of 10min, a washing step with methanol-phosphate buffer (20:80, v/v) and methanol as eluent. Recovery percentages obtained: 84% for eprosartan, 74% for telmisartan, 74% for irbesartan and 89% for valsartan allow the determination of these drugs concentration levels in urine.

QTL analysis of yield traits in an advanced backcross population derived from a cultivated Andean x wild common bean (Phaseolus vulgaris L.) cross.

Advanced backcross QTL analysis was used to identify quantitative trait loci (QTL) for agronomic performance in a population of BC2F(3:5) introgression lines created from the cross of a Colombian large red-seeded commercial cultivar, ICA Cerinza, and a wild common bean accession, G24404. A total of 157 lines were evaluated for phenological traits, plant architecture, seed weight, yield and yield components in replicated trials in three environments in Colombia and genotyped with microsatellite, SCAR, and phaseolin markers that were used to create a genetic map that covered all 11 linkage groups of the common bean genome with markers spaced at an average distance of every 10.4 cM. Segregation distortion was most significant in regions orthologous for a seed coat color locus (R-C) on linkage group b08 and two domestication syndrome genes, one on linkage group b01 at the determinacy (fin) locus and the other on linkage group b02 at the seed-shattering (st) locus. Composite interval mapping analysis identified a total of 41 significant QTL for the eight traits measured of which five for seed weight, two for days to flowering, and one for yield were consistent across two or more environments. QTL were located on every linkage group with b06 showing the greatest number of independent loci. A total of 13 QTL for plant height, yield and yield components along with a single QTL for seed size showed positive alleles from the wild parent while the remaining QTL showed positive alleles from the cultivated parent. Some QTL co-localized with regions that had previously been described to be important for these traits. Compensation was observed between greater pod and seed production and smaller seed size and may have resulted from QTL for these traits being linked or pleiotropic. Although wild beans have been used before to transfer biotic stress resistance traits, this study is the first to attempt to simultaneously obtain a higher yield potential from wild beans and to analyze this trait with single-copy markers. The wild accession was notable for being from a unique center of diversity and for contributing positive alleles for yield and other traits to the introgression lines showing the potential that advanced backcrossing has in common bean improvement.

MultiSimplex and experimental design as chemometric tools to optimize a SPE-HPLC-UV method for the determination of eprosartan in human plasma samples.

A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug eprosartan from human plasma samples. MultiSimplex program was used to optimize the HPLC-UV method due to the number of experimental and response variables to be studied. The measured responses were the corrected area, the separation of eprosartan chromatographic peak from plasma interferences peaks and the retention time of the analyte. The use of an Atlantis dC18, 100mmx3.9mm i.d. chromatographic column with a 0.026% trifluoroacetic acid (TFA) in the organic phase and 0.031% TFA in the aqueous phase, an initial composition of 80% aqueous phase in the mobile phase, a stepness of acetonitrile of 3% during the gradient elution mode with a flow rate of 1.25mL/min and a column temperature of 35+/-0.2 degrees C allowed the separation of eprosartan and irbesartan used as internal standard from plasma endogenous compounds. In the solid phase extraction procedure, experimental design was used in order to achieve a maximum recovery percentage. Firstly, the significant variables were chosen by way of fractional factorial design; then, a central composite design was run to obtain the more adequate values of the significant variables. Thus, the extraction procedure for spiked human plasma samples was carried out using C8 cartridges, phosphate buffer pH 2 as conditioning agent, a drying step of 10min, a washing step with methanol-phosphate buffer (20:80, v/v) and methanol as eluent liquid. The SPE-HPLC-UV developed method allowed the separation and quantitation of eprosartan from human plasma samples with an adequate resolution and a total analysis time of 1h.

Esophageal fibrovascular polyp protruding from the mouth.

A case of a 66-year-old woman with a giant fibrovascular polyp protruding from the mouth is presented. The polyp was successfully removed by a cervical esophagotomy.