The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform

Kenneth R Marcus - One of the best experts on this subject based on the ideXlab platform.

  • characterization of capillary channeled polymer fiber stationary phases for high performance Liquid Chromatography Protein separations comparative analysis with a packed bed column
    Analytical Chemistry, 2006
    Co-Authors: Dwella M Nelson, Kenneth R Marcus
    Abstract:

    Capillary-channeled polymer (C-CP) fibers are investigated as reversed-phase (RP) stationary phases for high-performance Liquid Chromatography of Proteins. A comparative analysis of column characteristics for polypropylene and poly(ethylene terephthalate) C-CP fiber columns and a conventional packed-bed (C4-derivatized silica) column has been undertaken. Five Proteins (ribonuclease A, cytochrome c, lysozyme, myoglobin, bovine serum albumin) were used to investigate the separation characteristics under typical RP gradient conditions. Column performance was compared under standard (identical) and optimized RP chromatographic conditions. The gradient compositions utilized with the C-CP fiber columns are similar to those used with conventional columns, employing flow rates in the 1−6 mL/min range and gradient rates of ∼1%/min. The packed-bed column was operated as prescribed by the column manufacturer. The retention factor (k‘), separation factor (α), resolution (Rs), asymmetry factor (As), elution order, and...

Mario Lise - One of the best experts on this subject based on the ideXlab platform.

  • Doxorubicin Activity Is Enhanced by Hyperthermia in a Model of Ex Vivo Vascular Perfusion of Human Colon Carcinoma
    World Journal of Surgery, 2003
    Co-Authors: Pierluigi Pilati, Simone Mocellin, Carlo R. Rossi, Romano Scalerta, Rita Alaggio, Luciano Giacomelli, Cristina Geroni, Donato Nitti, Mario Lise
    Abstract:

    There is little information on the pharmacokinetics and pharmacodynamics of doxorubicin (DXR) administered during locoregional treatments of colon carcinoma under hyperthermic conditions. The aim of this study was to evaluate distribution and activity of DXR in healthy tissue and tumor tissues under hyperthermic conditions by using an experimental model of ex vivo isolated vascular perfusion of human colon segments bearing primary carcinoma. The influence of topoisomerase-IIα (TPI2α) expression on the anti-cancer activity of DXR combined with heat was evaluated as well. Twenty seven colon segments surgically resected for primary carcinoma were perfused ex vivo under physiological conditions (group A, n = 7), with DXR (group B, n = 6), under hyperthermic conditions (group C, n = 6), and with the combination DXR–hyperthermia (group D, n = 8). Samples of perfusate and tissues (normal and pathologic) were collected during 90 minutes of perfusion. Doxorubicin concentration in perfusate and tissues was assessed with high-performance Liquid Chromatography. Protein expression of TPI2α, the main molecular target of DXR, was measured by image analysis in normal mucosa and tumor samples. Drug uptake was increased by heat equally in healthy and diseased tissue. Under hyperthermic conditions, DXR activity was significantly higher in pathologic mucosa than in normal mucosa. Furthermore, the activity of DXR combined with heat correlated with baseline TPI2α levels in tumor tissue. From these findings, it appears that heat sensitizes tumor cells—but not normal mucosa—to DXR activity. Furthermore, Protein levels of TPI2α in pretreatment samples could predict tumor sensitivity to DXR.

Dwella M Nelson - One of the best experts on this subject based on the ideXlab platform.

  • characterization of capillary channeled polymer fiber stationary phases for high performance Liquid Chromatography Protein separations comparative analysis with a packed bed column
    Analytical Chemistry, 2006
    Co-Authors: Dwella M Nelson, Kenneth R Marcus
    Abstract:

    Capillary-channeled polymer (C-CP) fibers are investigated as reversed-phase (RP) stationary phases for high-performance Liquid Chromatography of Proteins. A comparative analysis of column characteristics for polypropylene and poly(ethylene terephthalate) C-CP fiber columns and a conventional packed-bed (C4-derivatized silica) column has been undertaken. Five Proteins (ribonuclease A, cytochrome c, lysozyme, myoglobin, bovine serum albumin) were used to investigate the separation characteristics under typical RP gradient conditions. Column performance was compared under standard (identical) and optimized RP chromatographic conditions. The gradient compositions utilized with the C-CP fiber columns are similar to those used with conventional columns, employing flow rates in the 1−6 mL/min range and gradient rates of ∼1%/min. The packed-bed column was operated as prescribed by the column manufacturer. The retention factor (k‘), separation factor (α), resolution (Rs), asymmetry factor (As), elution order, and...

Pierluigi Pilati - One of the best experts on this subject based on the ideXlab platform.

  • Doxorubicin Activity Is Enhanced by Hyperthermia in a Model of Ex Vivo Vascular Perfusion of Human Colon Carcinoma
    World Journal of Surgery, 2003
    Co-Authors: Pierluigi Pilati, Simone Mocellin, Carlo R. Rossi, Romano Scalerta, Rita Alaggio, Luciano Giacomelli, Cristina Geroni, Donato Nitti, Mario Lise
    Abstract:

    There is little information on the pharmacokinetics and pharmacodynamics of doxorubicin (DXR) administered during locoregional treatments of colon carcinoma under hyperthermic conditions. The aim of this study was to evaluate distribution and activity of DXR in healthy tissue and tumor tissues under hyperthermic conditions by using an experimental model of ex vivo isolated vascular perfusion of human colon segments bearing primary carcinoma. The influence of topoisomerase-IIα (TPI2α) expression on the anti-cancer activity of DXR combined with heat was evaluated as well. Twenty seven colon segments surgically resected for primary carcinoma were perfused ex vivo under physiological conditions (group A, n = 7), with DXR (group B, n = 6), under hyperthermic conditions (group C, n = 6), and with the combination DXR–hyperthermia (group D, n = 8). Samples of perfusate and tissues (normal and pathologic) were collected during 90 minutes of perfusion. Doxorubicin concentration in perfusate and tissues was assessed with high-performance Liquid Chromatography. Protein expression of TPI2α, the main molecular target of DXR, was measured by image analysis in normal mucosa and tumor samples. Drug uptake was increased by heat equally in healthy and diseased tissue. Under hyperthermic conditions, DXR activity was significantly higher in pathologic mucosa than in normal mucosa. Furthermore, the activity of DXR combined with heat correlated with baseline TPI2α levels in tumor tissue. From these findings, it appears that heat sensitizes tumor cells—but not normal mucosa—to DXR activity. Furthermore, Protein levels of TPI2α in pretreatment samples could predict tumor sensitivity to DXR.

Mark G. Papich - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of plasma and interstitial fluid concentrations of doxycycline and meropenem following constant rate intravenous infusion in dogs.
    American Journal of Veterinary Research, 2003
    Co-Authors: Tara L. Bidgood, Mark G. Papich
    Abstract:

    Objective—To compare plasma (total and unbound) and interstitial fluid (ISF) concentrations of doxycycline and meropenem in dogs following constant rate IV infusion of each drug. Animals—6 adult Beagles. Procedure—Dogs were given a loading dose of doxycycline and meropenem followed by a constant rate IV infusion of each drug to maintain an 8-hour steady state concentration. Interstitial fluid was collected with an ultrafiltration device. Plasma and ISF were analyzed by high performance Liquid Chromatography. Protein binding and lipophilicity were determined. Plasma data were analyzed by use of compartmental methods. Results—Compared with meropenem, doxycycline had higher Protein binding (11.87% [previously published value] vs 91.75 ± 0.63%) and lipophilicity (partition coefficients, 0.02 ± 0.01 vs 0.68 ± 0.05). A significant difference was found between ISF and plasma total doxycycline concentrations. No significant difference was found between ISF and plasma unbound doxycycline concentrations. Concentrat...

  • Plasma pharmacokinetics and tissue fluid concentrations of meropenem after intravenous and subcutaneous administration in dogs
    American Journal of Veterinary Research, 2002
    Co-Authors: Tara L. Bidgood, Mark G. Papich
    Abstract:

    Objective—To estimate pharmacokinetic variables and measure tissue fluid concentrations of meropenem after IV and SC administration in dogs. Animals—6 healthy adult dogs. Procedure—Dogs were administered a single dose of meropenem (20 mg/kg) IV and SC in a crossover design. To characterize the distribution of meropenem in dogs and to evaluate a unique tissue fluid collection method, an in vivo ultrafiltration device was used to collect interstitial fluid. Plasma, tissue fluid, and urine samples were analyzed by use of high-performance Liquid Chromatography. Protein binding was determined by use of an ultrafiltration device. Results—Plasma data were analyzed by compartmental and noncompartmental pharmacokinetic methods. Mean ± SD values for half-life, volume of distribution, and clearance after IV administration for plasma samples were 0.67 ± 0.07 hours, 0.372 ± 0.053 L/kg, and 6.53 ± 1.51 mL/min/kg, respectively, and half-life for tissue fluid samples was 1.15 ± 0.57 hours. Half-life after SC administrati...