@article{waddle_fine_case_trogdon_tyczkowska_frazier_page_1999, title={Phase I and pharmacokinetic analysis of high-dose tamoxifen and chemotherapy in normal and tumor-bearing dogs}, volume={44}, ISSN={["0344-5704"]}, DOI={10.1007/s002800050947}, abstractNote={{"Label"=>"PURPOSE", "NlmCategory"=>"OBJECTIVE"} To determine whether tamoxifen plasma concentrations capable of blocking P-glycoprotein (Pgp) in vitro can be safely achieved in dogs and whether doxorubicin pharmacokinetic alterations occur when tamoxifen is coadministered. {"Label"=>"METHODS", "NlmCategory"=>"METHODS"} Tamoxifen dose escalation studies were conducted in 7 normal dogs and in 19 tumor-bearing dogs receiving full-dose chemotherapy. Plasma tamoxifen and serum doxorubicin disposition were analyzed for putative drug interactions. {"Label"=>"RESULTS", "NlmCategory"=>"RESULTS"} Steady-state plasma concentrations of tamoxifen and N-desmethyl tamoxifen (NDMT) were 5-10 microM following oral tamoxifen administration at 600 mg/m2 every 12 h for 7 days to normal and tumor-bearing dogs. Mild-moderate gastrointestinal toxicity (diarrhea, anorexia) and reversible neurotoxicity were observed in dogs receiving chemotherapy plus high-dose tamoxifen. Myelosuppression was not affected by combined treatment in tumor-bearing dogs. High-dose tamoxifen decreased the clearance and volume of distribution of full-dose doxorubicin. {"Label"=>"CONCLUSIONS", "NlmCategory"=>"CONCLUSIONS"} Concentrations of tamoxifen/ NDMT sufficient to inhibit Pgp may be achieved in dogs receiving full-dose chemotherapy with a moderate but acceptable increase in gastrointestinal toxicity. Tamoxifen affects doxorubicin metabolism in dogs at high doses resulting in increased serum exposure. Pharmacologic manipulation of Pgp expression or function in normal and tumor tissue in dogs may facilitate investigation of novel anticancer treatment strategies in humans.}, number={1}, journal={CANCER CHEMOTHERAPY AND PHARMACOLOGY}, author={Waddle, JR and Fine, RL and Case, BC and Trogdon, ML and Tyczkowska, K and Frazier, D and Page, RL}, year={1999}, month={Jul}, pages={74–80} }
 @article{musser_anderson_tyczkowska_1998, title={Pharmacokinetic parameters and milk concentrations of ketoprofen after administration as a single intravenous bolus dose to lactating goats}, volume={21}, DOI={10.1046/j.1365-2885.1998.00148.x}, abstractNote={Six clinically normal lactating does were administered ketoprofen (2.2 mg/kg intravenously (i. v.)). Blood and milk samples were collected prior to and for 24 h after drug administration. Drug concentrations in serum and milk were determined by high performance liquid chromatography. Pharmacokinetic parameters from each goat were combined to obtain mean estimates (mean ± SD) of half‐life of elimination (t½β) of 0.32 ± 0.14 h, systemic clearance (Cl) of 0.74 ± 0.12 L/kg· h, and volume of distribution at steady state (Vss) of 0.23 ± 0.051 L/kg. In milk, ketoprofen was unmeasurable by the method employed (level of detection 25 ng/mL) for all samples.}, number={5}, journal={Journal of Veterinary Pharmacology and Therapeutics}, author={Musser, J. M. B. and Anderson, K. L. and Tyczkowska, K. L.}, year={1998}, pages={358–363} }
 @article{keever_voyksner_tyczkowska_1998, title={Quantitative determination of ceftiofur in milk by liquid chromatography electrospray mass spectrometry}, volume={794}, ISSN={["0021-9673"]}, DOI={10.1016/S0021-9673(97)00933-3}, abstractNote={A liquid chromatography–electrospray mass spectrometry (LC–ES-MS) was developed for the quantitation of ceftiofur in milk at the 50 ppb tolerance level set by the US Food and Drug Administration (FDA) for the drug. The method used ultrafiltration as a simple and rapid means to prepare the sample for analysis. A 100 μl volume of ultrafiltrate containing ceftiofur was concentrated on-column for LC–MS analysis. The LC separation was accomplished using an acetonitrile gradient with the ion-pair reagent heptafluorobutyric acid (HFBA). Propionic acid was added after the LC column to minimize electrospray signal suppression, enhancing the response for ceftiofur by a factor of 10. The transmission ions from the electrospray interface to the MS was enhanced by a factor of 7 by using a Rf ion guide. The development method could detect ceftiofur to 10 ppb and quantitate the antibiotic from 25–200 ppb (linear correlation coefficient of 0.993). The analysis indicated that bovine milk collected 32 h after dosing with ceftiofur was above the FDA tolerance of 50 ppb, while milk collected 48 h after dosing was found to contain 24–31 ppb of ceftiofur.}, number={1-2}, journal={JOURNAL OF CHROMATOGRAPHY A}, author={Keever, J and Voyksner, RD and Tyczkowska, KL}, year={1998}, month={Jan}, pages={57–62} }
 @article{tyczkowska_voyksner_anderson_papich_1994, title={Simultaneous determination of enrofloxacin and its primary metabolite ciprofloxacin in bovine milk and plasma by ion-pairing liquid chromatography}, volume={658}, ISSN={0378-4347}, url={http://dx.doi.org/10.1016/0378-4347(94)00243-6}, DOI={10.1016/0378-4347(94)00243-6}, abstractNote={A simple and sensitive high-performance liquid chromatographic method has been developed for the simultaneous determination of enrofloxacin and ciprofloxacin in bovine milk and plasma. Sample preparation consisted of mixing equal volumes of milk or plasma with acetonitrile-0.1 M sodium hydroxide (1:1, v/v), followed by ultrafiltration through 3000 Da molecular mass cut-off filters. Separation of these two fluoroquinolones in milk or plasma ultrafiltrate was accomplished by ion-pairing liquid chromatography using a reversed-phase analytical column eluted with acetonitrile-methanol-water. Ultraviolet absorbance of the column effluent was monitored over the 230-350 nm range with a photodiode-array detector (lambda max 278 nm). Recoveries of enrofloxacin from bovine milk and plasma were 92-107% and 80-84%, respectively. Recoveries of ciprofloxacin from bovine milk and plasma were 92-105% and 73-75%, respectively. The limit of detection for the two compounds was 5 ng/ml. Enrofloxacin was administered intravenously to a lactating cow at a dose of 2.5 mg/kg. Enrofloxacin was detected in milk within 15 min after injection and the metabolite ciprofloxacin rapidly appeared in plasma and milk. Both enrofloxacin and ciprofloxacin were below the limit of detection (5 ng/ml) by 48 h after drug administration.}, number={2}, journal={Journal of Chromatography B: Biomedical Sciences and Applications}, publisher={Elsevier BV}, author={Tyczkowska, Krystyna L. and Voyksner, Robert D. and Anderson, Kevin L. and Papich, Mark G.}, year={1994}, month={Aug}, pages={341–348} }
 @article{tyczkowska_voyksner_straub_aronson_1994, title={Simultaneous multiresidue analysis of beta-lactam antibiotics in bovine milk by liquid chromatography with ultraviolet detection and confirmation by electrospray mass spectrometry}, volume={77}, number={5}, journal={Journal of AOAC International}, author={Tyczkowska, K. L. and Voyksner, R. D. and Straub, R. F. and Aronson, A. L.}, year={1994}, pages={1122} }
 @article{tyczkowska_voyksner_anderson_aronson_1993, title={DETERMINATION OF CEFTIOFUR AND ITS METABOLITE DESFUROYLCEFTIOFUR IN BOVINE SERUM AND MILK BY ION-PAIRED LIQUID-CHROMATOGRAPHY}, volume={614}, ISSN={["0378-4347"]}, DOI={10.1016/0378-4347(93)80231-R}, abstractNote={A simple and sensitive liquid chromatographic method has been developed for the simultaneous determination of ceftiofur and its metabolite desfuroylceftiofur in bovine serum and milk. The method involved an ultrafiltration of diluted serum/milk with an equal volume of 50% acetonitrile through a 10,000 dalton molecular mass cut-off filter. Separation of ceftiofur and desfuroylceftiofur from the other serum/milk components was performed by ion-paired (octane and dodecanesulfonate) liquid chromatography using a reversed-phase column eluted with acetonitrile-water solution. The ultraviolet-visible absorbance of the column effluent was monitored in 200-350 nm range of a photodiode-array detector or at lambda max 289.6 nm for ceftiofur, lambda max 265.8 nm for desfuroylceftiofur and lambda max 271.4 nm for dimer of desfuroylceftiofur. Recoveries of ceftiofur from bovine milk spiked with 1 and 10 micrograms/ml were 95.9 and 97.0% with coefficients of variation of 3.69 and 2.51%, respectively. Recovery of ceftiofur from bovine serum spiked with 10 micrograms/ml was 90.4% with a coefficient of variation of 5.29%. A correlation coefficient of 0.9992 occurred with ceftiofur in aqueous solutions (n = 5, in duplicates). The limit of detection was estimated to be approximately 50 ppb (ng/ml). Additionally, this paper documents the presence of a ceftiofur metabolite in bovine serum under in vitro and in vivo conditions. The metabolite was identified as desfuroylceftiofur together with its dimer 3,3'-desfuroylceftiofur disulfide by thermospray liquid chromatography-mass spectrometry.}, number={1}, journal={JOURNAL OF CHROMATOGRAPHY-BIOMEDICAL APPLICATIONS}, author={TYCZKOWSKA, KL and VOYKSNER, RD and ANDERSON, KL and ARONSON, AL}, year={1993}, month={Apr}, pages={123–134} }
 @article{tyczkowska_voyksner_aronson_1991, title={DEVELOPMENT OF AN ANALYTICAL METHOD FOR CEPHAPIRIN AND ITS METABOLITE IN BOVINE-MILK AND SERUM BY LIQUID-CHROMATOGRAPHY WITH UV-VIS DETECTION AND CONFIRMATION BY THERMOSPRAY MASS-SPECTROMETRY}, volume={14}, ISSN={["0140-7783"]}, DOI={10.1111/j.1365-2885.1991.tb00804.x}, abstractNote={Metabolites of the cephapirin ß‐lactam antibiotic have not previously been reported in bovine milk. The principal metabolite was tentatatively identified as desacetylcephapirin by liquid chromatography with UV‐VIS photodiode array (LC/UV‐VIS PDA), and liquid‐chromatography‐mass‐spectrometric (LC‐MS) detection. Synthetic desacetylcephapirin was prepared by incubation of cephapirin in bovine milk and serum at 37d̀C. Also, a method for determining cephapirin in bovine milk and serum was developed. The detection limits for cephapirin and desacetylcephapirin were estimated to be 10 and 50 ug/kg, respectively, for LC/UV‐VIS PDA, and 100 and 500 ug/kg for LC‐MS.}, number={1}, journal={JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS}, author={TYCZKOWSKA, KL and VOYKSNER, RD and ARONSON, AL}, year={1991}, month={Mar}, pages={51–60} }
 @article{tyczkowska_page_riviere_1990, title={DETERMINATION OF CARBOPLATIN IN CANINE PLASMA BY LIQUID-CHROMATOGRAPHY WITH ULTRAVIOLET VISIBLE DETECTION AND CONFIRMATION BY ATOMIC-ABSORPTION SPECTROSCOPY}, volume={527}, ISSN={["0378-4347"]}, DOI={10.1016/S0378-4347(00)82130-1}, number={2}, journal={JOURNAL OF CHROMATOGRAPHY-BIOMEDICAL APPLICATIONS}, author={TYCZKOWSKA, K and PAGE, RL and RIVIERE, JE}, year={1990}, month={May}, pages={447–453} }
 @article{riond_hedeen_tyczkowska_riviere_1989, title={DETERMINATION OF DOXYCYCLINE IN BOVINE-TISSUES AND BODY-FLUIDS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY USING PHOTODIODE ARRAY ULTRAVIOLET-VISIBLE DETECTION}, volume={78}, ISSN={["0022-3549"]}, DOI={10.1002/jps.2600780112}, abstractNote={A sensitive and selective high-performance liquid chromatographic assay was developed to quantitate doxycycline concentrations in bovine tissues and body fluids. The method involved sonication of doxycycline-spiked minced tissues with appropriate solutions to extract tissue-bound drug. Acetonitrile:85% phosphoric acid:water (20:2:78) was added to doxycycline-spiked serum or urine. The mixtures were ultrafiltered through 30,000 or 10,000 Da molecular weight cutoff microseparation systems. Separation was obtained by a reversed-phase microbore column. Absorbance of the column effluent was measured by an ultraviolet-visible photodiode array detector scanning from 235 to 380 nm and/or a photometric detector operated at 268 or 345 nm. Chromatographic peak homogeneity was evaluated by three-dimensional spectrochromatograms, contour maps, and absorbance ratios.}, number={1}, journal={JOURNAL OF PHARMACEUTICAL SCIENCES}, author={RIOND, J and HEDEEN, KM and TYCZKOWSKA, K and RIVIERE, JE}, year={1989}, month={Jan}, pages={44–47} }
 @article{tyczkowska_voyksner_aronson_1989, title={Development of an analytical method for penicillin G in bovine milk by liquid chromatography with ultraviolet-visible detection and confirmation by mass spectrometric detection}, volume={490}, number={1}, journal={Journal of Chromatography. A}, author={Tyczkowska, K. and Voyksner, R. D. and Aronson, A. L.}, year={1989}, pages={101} }
 @article{tyczkowska_hedeen_aucoin_aronson_1989, title={HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR THE SIMULTANEOUS DETERMINATION OF ENROFLOXACIN AND ITS PRIMARY METABOLITE CIPROFLOXACIN IN CANINE SERUM AND PROSTATIC TISSUE}, volume={493}, ISSN={["0378-4347"]}, DOI={10.1016/S0378-4347(00)82739-5}, abstractNote={A simple and sensitive high-performance liquid chromatographic method was developed for the determination of enrofloxacin and ciprofloxacin in canine serum and prostatic tissue. Sample preparation consisted of mixing canine serum with a 1:1 dilution of acetonitrile and 0.1 M sodium hydroxide followed by ultrafiltration through a 10 000 molecular mass cut-off filter. Prostatic tissue was sonicated with the same solution prior to ultrafiltration. Separation of these two quinolones in the ultrafiltrate was accomplished by ion-paired liquid chromatography using a reversed-phase analytical column eluted with an acetonitrile-methanol-water solution. Enrofloxacin and ciprofloxacin were detected by a photometric ultraviolet-visible detector set at 278.6 nm and confirmed by a photodiode array detector operating from 230 to 360 nm. The limits of detection for enrofloxacin and ciprofloxacin were 4 and 2 ng/ml, respectively.}, number={2}, journal={JOURNAL OF CHROMATOGRAPHY-BIOMEDICAL APPLICATIONS}, author={TYCZKOWSKA, K and HEDEEN, KM and AUCOIN, DP and ARONSON, AL}, year={1989}, month={Sep}, pages={337–346} }
 @article{riond_tyczkowska_riviere_1989, title={Pharmacokinetics and metabolic inertness of doxycycline in calves with mature or immature rumen function}, volume={50}, journal={American Journal of Veterinary Research}, author={Riond, J. L. and Tyczkowska, K. and Riviere, J. E.}, year={1989}, pages={1329–1333} }
 @article{mcgahan_tyczkowska_1987, title={THE DETERMINATION OF PLATINUM IN BIOLOGICAL-MATERIALS BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROSCOPY}, volume={42}, ISSN={["0584-8547"]}, DOI={10.1016/0584-8547(87)80122-2}, abstractNote={Methods for determination of platinum in body tissues and fluids by electrothermal atomic absorption spectroscopy are described. Serum and urine could be analyzed without pretreatment or dilution. Wet and dry ashing techniques for tissue digestion were compared. Dry ashing tissues in a furnace resulted in significant and unexplained losses of analyte, whereas there was complete recovery of platinum added to the tissues when the tissues were wet ashed. The wet ashing technique is fast and convenient and requires minimal sample treatment.}, number={5}, journal={SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY}, author={MCGAHAN, MC and TYCZKOWSKA, K}, year={1987}, pages={665–668} }
 @article{riviere_page_dewhirst_tyczkowska_thrall_1986, title={Effect of hyperthermia on cisplatin pharmacokinetics in normal dogs}, volume={2}, DOI={10.3109/02656738609004965}, abstractNote={In vitro and in vivo cisplatin pharmacokinetic studies were conducted at 37 degrees C and 42-43 degrees C in dogs. Cisplatin at 1, 2, 3, 4 and 5 micrograms/ml was incubated with canine serum at 37 degrees and 43 degrees C. Aliquots were processed immediately for atomic absorption spectrophotometry to determine total as well as free, ultrafilterable cisplatin concentrations. Thirteen healthy, average-sized mongrel dogs received 1 mg/kg cisplatin as an intravenous bolus. Four were maintained unanaesthetized at 37 degrees C, two were anaesthetized and maintained at 37 degrees C and seven were anaesthetized and maintained at a rectal temperature of 42 degrees C for 60 min. Serum samples were obtained and processed for free and total cisplatin. There were no detectable concentration effects present in either in vitro group. The rate constant reflecting the decay of free cisplatin at 37 degrees C was 0.0035 +/- 0.0007 min-1 and increased significantly (P less than 0.0001) to 0.0053 +/- 0.001 min-1 at 43 degrees C. In vivo pharmacokinetic analysis consisted of model-independent parameters (total body clearance, volume of distribution, half-life and mean residence time). A significant increase (P less than or equal to 0.05) in all parameters was observed with free-cisplatin at 42 degrees C. This data would indicate that at the elevated temperatures encountered in whole body hyperthermia, the rate of formation of reactive metabolites from parent cisplatin is increased.(ABSTRACT TRUNCATED AT 250 WORDS)}, journal={International Journal of Hyperthermia}, author={Riviere, J. E. and Page, R. L. and Dewhirst, M. W. and Tyczkowska, K. and Thrall, D. E.}, year={1986}, pages={351–358} }