Capillary zone electrophoresis method to assay tipranavir capsules and identification of oxidation product and organic impurity by quadrupole-time of flight mass spectrometry.

Tipranavir (TPV) is one of the most recently developed protease inhibitors (PI) and it is specially recommended for treatment-experienced patients who are resistant to other PI drugs. In this work, a simple and friendly environmental CZE stability-indicating method to assay TPV capsules was developed and two TPV organic impurities were identified by high resolution mass spectrometry (HRMS). The optimized analytical conditions were: background electrolyte composed of sodium borate 50mM, pH 9.0 and 5% of methanol; voltage + 28kV; hydrodynamic injection of 5s (100mbar), detection wavelength 240nm, at 25°C. The separation was achieved in a fused silica capillary with 50µm × 40cm (inner diameter × effective length), using furosemide as internal standard. All the validation parameters were met and the method was specific, even in the presence of degradation products and impurities. Oxidation was indicated as the main degradation pathway among those evaluated in this study (acidic, alkaline, thermal, photolytic and oxidative) and it showed a second order degradation kinetic, under the conditions used in this study. The main oxidation product and an organic impurity detected in the standard were characterized by Q-TOF, and both of them correspond to oxidation products of TPV.

Lipocalina associada à gelatinase neutrofílica(NGAL) como um biomarcador de lesão renal: uma revisão / Neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker of kidney damage: a review

Lipocalina associada à gelatinase neutrofílica (NGAL) é uma molécula proteica predominantemente expressa na parte distal do néfron após a ocorrência de lesão renal. Diferentemente da creatinina sérica e da taxa de filtração glomerular, que são marcadores de função renal, os níveis aumentados de NGAL, tanto no soro quanto na urina, estão intimamente ligados a lesões estruturais do néfron.Os estudos clínicos indicam que poucas horas após a ocorrência da lesão renal aguda os níveis séricos e urinários de NGAL já se apresentam significativamente elevados, enquanto os níveis séricos de creatinina e a sua depuração renal apenas sofrem alterações significativas entre 24-48hapós a lesão. Assim, a utilização de marcadores de função renal, usualmente avaliados na práticaclínica, pode apresentar algumas limitações além de dificultar a aplicação de medidas precoces quevisam a proteção renal. Esta revisão da literatura tem por objetivo analisar os aspectos biológicos e as aplicações da mensuração de NGAL em algumas condições clínicas, incluindo injúria renal, nefropatias e isquemia renal.

Neutrophil gelatinase-associated lipocalin (NGAL) is a protein molecule predominantly expressed in the distal part of the nephron following the occurrence of renal damage. Differently from serum creatinine and glomerular filtration rate, which are markers of renal function, increased levels of NGAL in both serum and urine are closely linked to structural damage of the nephron. Clinical studies indicate that within a few hours of occurrence Of acute renal injury serum and urinary NGAL levels are already significantly elevated, while serum creatinine levels and renal clearance only change significantly between 24-48 hours after injury. Thus, the use of renal function markers, usually evaluated in practice, may present some limitations, as well as hinder the application of early measures that aim at renal protection. This review of the literature aims to analyze the biological aspects and applications of NGAL measurement in some clinical conditions, including renal injury, nephropathy and renal ischemia.

Neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker of kidney damage: a review / Lipocalina associada à gelatinase neutrofílica (NGAL) como um biomarcador de lesão renal: uma revisão

Neutrophil gelatinase- associated lipocalin (NGAL) is a protein molecule predominantly expressed in the distal nephron after the occurrence of renal injury. Unlike the serum creatinine and the glomerular filtration rate, which are the renal function markers, the increased levels of NGAL, both in serum and urine, are closely linked to the structural injury to the nephron. Clinical studies indicate that a few hours after the occurrence of acute renal injury, the serum and urinary levels of NGAL are already significantly elevated, while the serum creatinine levels and renal clearance only undergo significant changes between 24-48h after injury. Thus, the use of renal function markers, usually assessed in the clinical practice, they may have some limitations also hindering the implementation of early measures aimed at protecting the kidneys. This literature review aims at examining the biological aspects and the applications of NGAL measurement in some clinical conditions, including kidney failure, kidney diseases and renal ischemia.

Lipocalina associada à gelatinase neutrofílica (NGAL) é uma molécula proteica predominantemente expressa na parte distal do néfron após a ocorrência de lesão renal. Diferentemente da creatinina sérica e da taxa de filtração glomerular, que são marcadores de função renal, os níveis aumentados de NGAL, tanto no soro quanto na urina, estão intimamente ligados a lesões estruturais do néfron. Os estudos clínicos indicam que poucas horas após a ocorrência da lesão renal aguda os níveis séricos e urinários de NGAL já se apresentam significativamente elevados, enquanto os níveis séricos de creatinina e a sua depuração renal apenas sofrem alterações significativas entre 24-48h após a lesão. Assim, a utilização de marcadores de função renal, usualmente avaliados na prática clínica, pode apresentar algumas limitações além de dificultar a aplicação de medidas precoces que visam a proteção renal. Esta revisão da literatura tem por objetivo analisar os aspectos biológicos e as aplicações da mensuração de NGAL em algumas condições clínicas, incluindo injúria renal, nefropatias e isquemia renal.