ABSTRACT
Myriocin is a potent inhibitor of serine-palmitoyl-transferase, the first and rate-determining enzyme in the sphingolipids biosynthetic pathway. This study developed, validated and applied a LC-MS/MS method to measure myriocin in minute specimens of animal tissue. The chemical analog 14-OH-myriocin was used as the internal standard. The two molecules were extracted from the tissue homogenate by solid-phase extraction, separated by gradient reversed-phase liquid chromatography and measured by negative ion electrospray mass spectrometry in the triple quadrupole. Detection was accomplished by multiple reaction monitoring, employing the most representative transitions, 400@104 and 402@104 for myriocin and 14-OH-myriocin, respectively. The typical limit of detection and lower limit of quantitation of the optimized method were 0.9 pmol/mL (~0.016 pmol injected) and 2.3 pmol/mL, respectively, and the method was linear up to 250 pmol/mL range (r2 = 0.9996). The intra- and between-day repeatability afforded a coefficient of variation ≤7.0%. Applications included quantification of myriocin in mouse lungs after 24 h from administration of ~4 nmol by intra-tracheal delivery. Measured levels ranged from 4.11 (median; 2.3-7.4 IQR, n = 4) to 11.7 (median; 7.6-22.7 interquartile range (IQR), n = 6) pmol/lung depending on the different formulations used. Myriocin was also measured in retinas of mice treated by intravitreal injection and ranged from 0.045 (less than the limit of detection) to 0.35 pmol/retina.
Subject(s)
Fatty Acids, Monounsaturated/analysis , Fatty Acids, Monounsaturated/pharmacokinetics , Serine C-Palmitoyltransferase/antagonists & inhibitors , Tandem Mass Spectrometry/methods , Animals , Chromatography, Reverse-Phase , Fatty Acids, Monounsaturated/chemistry , Female , Limit of Detection , Linear Models , Lung/chemistry , Lung/metabolism , Male , Mice , Mice, Inbred C57BL , Reproducibility of Results , Retina/chemistry , Retina/metabolism , Spectrometry, Mass, Electrospray Ionization/methods , Tissue DistributionABSTRACT
La expansión de tejidos es un procedimiento bien aceptado con el objetivo de aumentar superfi cie o volumen de tejidos mediante fuerza expansiva. La expansión intraoperatoria rápida en mastoplastias de aumento (IREBA - intraoperatory rapid expansion breast augmentation) nos ha brindado una ostensible ayuda en la obtención de buenos resultados quirúrgicos, especialmente en las mastoplastias de mamas asimétricas. Se presenta un simple y fácil recurso para efectuar el decolamiento del bolsillo protésico y determinar el mejor volumen a colocar. Luego de una meticulosa hemostasia, introducimos un expansor (sizer) redondo de 600 cc, el cual es llenado con solución salina hasta lograr el volumen deseado, para luego sobreexpandirlo hasta su máxima capacidad. Se evaluaron 150 casos aleatorizados de procedimientos efectuados en el período 1998-2015, y no se registraron complicaciones en la serie atribuibles al procedimiento.
Tissue expansion is a well-acepted procedure to stretch and grove tissues in response to expansive forces. Intraoperative rapid expansion in breast augmentation (IREBA) has signifi cantly improved our surgical results. In this paper, the author presents an easy technical resource to perform a breast pocket, and to determine the best implant size, specially to breast asymmetries management. After a meticulous haemostasis, a round base expander (600 cc) is introduced and fi lled with saline solution with a 60 cc. syringe or electric pump device, to obtain the augmentation size. Then, we continue fi lling the expander to twice the volume of the fi nal prosthesis size. We randomly evaluated 150 patient records of mammary augmentation procedures between 1998-2008, and no major complications were noted in our series performed with this procedure.
