Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Optimum conditions for the direct reversed-phase LC determination of fluoride based on the ternary M-(F-)-(5-Br-PADAP) complexes [M = ZrIV or HfIV and 5-Br-PADAP = 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol] were evaluated. Chromatographic separation was performed with C18 end-capped column with an eluent consisting of acetonitrile-water (85 + 15 v/v) mixture of pH 4.0 +/- 0.3 (flow rate 1 ml min-1), and the eluate was monitored spectrophotometrically at lambda max = 585 nm. The calibration curves were linear over a wide range of fluoride concentrations: from 1 to 110 and 150 ng ml-1 for the ZrIV-(F-)-(5-Br-PADAP) and HfIV-(F-)-(5-Br-PADAP) systems, respectively (using a 20 microliters loop). Under such conditions the detection limits were 0.8 and 0.7 ng ml-1, respectively, and the quantification limit is 1.0 ng ml-1 for both methods. When a 100 microliters loop was used, the limits of both detection and quantification in the method based on the zirconium system were 0.2 ng ml-1. Using the proposed method, fluoride was determined directly in tap water, saliva and an anti-cancer agent for prostatic cancer (Leuprolid).
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PMID:Sensitive reversed-phase liquid chromatographic determination of fluoride based on its ternary systems with zirconium(IV) or hafnium(IV) and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol. 983 Jan 65

A method has been developed for the semiquantitative analysis of the catechol estrogens, 2- and 4-hydroxyestradiol, using tandem electrospray mass spectrometry in a quadrupole ion trap mass analyzer. The implication of catechol estrogens in the biogenesis of breast and prostate cancer makes these labile lipophilic compounds important analytical targets. Ferrocene boronic acid is reacted with 2- and 4-hydroxyestradiol to form their cyclic boronate esters. Sample ionization is accomplished during the electrospray process by a one-electron oxidation of the ferrocene functionality to form the radical cation. The analysis depends on a non-aqueous solvent system consisting of 90% acetonitrile and 10% dichloromethane with 100 microM lithium triflate as the supporting electrolyte. The sensitivity of the analysis is greatly increased by the use of a novel electrospray interface with a large surface area stainless steel electrode coupled to a pulled fused-silica needle. Collision-induced dissociation of the selected molecular ion within the ion trap produces fragment ion spectra that can be used to distinguish between the two isobaric isomers and ultimately determine the relative amounts in mixtures containing both components. The method is sensitive to analyte concentrations in the low nM range.
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PMID:Ratiometric analysis of the ferrocene boronate esters of 2- and 4-hydroxyestradiol by tandem electrospray mass spectrometry. 1118 May 48

Kahalalide F (KF) is a novel cyclic depsipeptide anticancer drug, which has shown anticancer activity both in vitro and in vivo especially against human prostate cancer cell lines. To characterize the pharmacokinetics of KF during a phase I clinical trial in patients with androgen refractory prostate cancer, a method was developed and validated for the quantitative analysis of KF in human plasma using high-performance liquid chromatography (HPLC) coupled to positive electrospray ionization tandem mass spectrometry (ESI-MS/MS). Microbore reversed-phase liquid chromatography (LC) performed with mobile phases containing trifluoroacetic acid, an additive commonly used for separating peptides, resulted in substantial suppression of the signal for KF on ESI-MS/MS. An alternative approach employing a basic mobile phase provided an excellent response for KF when detected in the positive ion mode. Plasma samples were prepared for LC MS/MS by solid-phase extraction on C(18) cartridges. The LC separation was performed on a Zorbax Extend C(18) column (150 x 2.1 mm i.d., particle size 5 micro m) with acetonitrile -10 mM aqueous ammonia (85 : 15, v/v) as the mobile phase, at a flow-rate of 0.20 ml min(-1). A butyric acid analogue of KF was used as the internal standard. The lower limit of quantitation (LLQ) using a 500 micro l sample volume was 1 ng ml(-1) and the linear dynamic range extended to 1000 ng ml(-1). The inter-assay accuracy of the assay was -15.1% at the LLQ and between -2.68 and -9.05% for quality control solutions ranging in concentration from 2.24 to 715 ng ml(-1). The inter-assay precision was 9.91% or better at these concentrations. The analyte was stable in plasma under all relevant conditions evaluated and for a period of 16 h after reconstituting plasma extracts for LC analysis at ambient temperature.
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PMID:Quantitative analysis of the novel depsipeptide anticancer drug Kahalalide F in human plasma by high-performance liquid chromatography under basic conditions coupled to electrospray ionization tandem mass spectrometry. 1227 42

A method for the determination of I, a peptide-doxorubicin conjugate that was evaluated for the treatment of prostate cancer, and two of its active metabolites, doxorubicin and leucine-doxorubicin is described. Blood samples were chilled immediately after being drawn in order to prevent ex vivo entry of the metabolites into red blood cells. EDTA (10 mg/ml final concentration) was used to prevent plasma-mediated degradation of the peptide portion of the prodrug. After the addition of internal standard, plasma was prepared for analysis using a C-8 solid-phase extraction column. In order to overcome secondary ionic interactions with the silica-based extraction column, the analytes were eluted with ammonium hydroxide in methanol. The extracts were evaporated to dryness, reconstituted, and assayed by step change, gradient, reverse phase HPLC with fluorescence detection. Two interfering metabolites found in post dose plasma were chromatographically separated by an adjustment of the mobile phase pH. The within-day reproducibility of the doxorubicin and leucine-doxorubicin chromatographic retention times was improved by a brief washing of the analytical column with 90% acetonitrile after each injection. The range of the standard curve was 12.5-1250 ng/ml for doxorubicin and 25-2500 ng/ml for I and leucine-doxorubicin.
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PMID:Determination of a peptide-doxorubicin, prostate-specific antigen activated prodrug, and its active metabolites in human plasma using high-performance liquid chromatography with fluorescence detection. Stabilization of the peptide prodrug with EDTA. 1238 93

A liquid chromatographic-electrospray ionization-mass spectrometric (LC-ESI-MS) technique was developed to simultaneously determine the cyclooxygenase metabolites of arachidonic acid (6-keto-PGF(1alpha), PGD(2), PGE(2), PGF(2alpha), and PGJ(2)) produced by cultured cells. Samples were separated on a C(18) column with water-acetonitrile mobile phase, ionized by electrospray, and detected in the positive mode. Selected ion monitoring (SIM) of m/z 353, 335, 335, 319, and 317 were used for quantifying 6-keto-PGF(1alpha), PGD(2), PGE(2), PGF(2alpha), and PGJ(2), respectively. Prostaglandins were detected at concentrations as low as 1 pg (S/N=3) on the column. The method was used to determine the production of PGs from bovine coronary artery endothelial cells (ECs) and human prostate cancer cells (PC-3) with different degree of invasiveness. Bradykinin (10(-6) M) stimulated a marked increase in the production of 6-keto-PGF(1alpha), PGE(2), and PGF(2alpha) and a small increase of PGD(2) by ECs. 6-Keto-PGF(1alpha) was the major metabolite in these cells. The production of PGE(2) was threefold higher and PGD(2) was twofold higher in PC-3-S (invasive) cells than in PC-3-U (non-invasive) cells.
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PMID:Liquid chromatographic-mass spectrometric determination of cyclooxygenase metabolites of arachidonic acid in cultured cells. 1253 46

A simple method for simultaneous determination of androstenediol 3-sulfate (Adiol-3S) and dehydroepiandrosterone sulfate (DHEA-S) in human serum using isotope diluted liquid chromatography-electrospray ionization-ion trap-mass spectrometry (LC-ESI-ion trap-MS) was developed. After addition of deuterated internal standards ([2H5]Adiol-3S and [2H4]DHEA-S), human serum (100 microl) was deproteinized with acetonitrile and then applied to a solid-phase extraction cartridge, Oasis HLB. The obtained steroid sulfates fraction was washed with hexane and then analyzed by LC-ESI-MS operated in the negative ion mode. The quantification ranges of Adiol-3S and DHEA-S were 10-400 ng/ml and 0.05-8 microg/ml, respectively. The method does not require the chemical or enzymatic hydrolysis of the conjugates and purification with high-performance liquid chromatography, and shows satisfactory reproducibility and accuracy. The concentrations of these sulfates in the sera of healthy male volunteers (n=14) were 19.2-245.3 mg/ml (Adiol-3S) and 0.175-5.16 microg/ml (DHEA-S), and those of patients with prostate cancer (n=19) were 15.3-182.7 ng/ml (Adiol-3S; four samples, not detectable) and 0.110-2.421 microg/ml (DHEA-S).
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PMID:Simultaneous determination of androstenediol 3-sulfate and dehydroepiandrosterone sulfate in human serum using isotope diluted liquid chromatography-electrospray ionization-mass spectrometry. 1455 23

Atrasentan (A-147627) is an endothelin antagonist receptor being developed at Abbott Laboratories for the treatment of prostate cancer. A quick and sensitive method for the determination of atrasentan in human plasma has been developed and validated using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. A dual-column, single mass spectrometer system is used to provide a reliable and routine means to increase sample throughput. The analytical method involves liquid-liquid extraction and internal standard (A-166790). The plasma samples and internal standard are acidified with 0.3 M hydrochloric acid prior to being extracted into 1:1 (v/v) hexanes--methyl t-butyl ether. The organic extract was evaporated to dryness using heated nitrogen stream and reconstituted with mobile phase. Atrasentan and internal standard were separated with no interference in a Zorbax SB-C(18) analytical column with 2.1 x 50 mm, 5 microm, and a Zorbax C(8) guard column using a mobile phase consisting of 50:50 (v:v) acetonitrile--0.05 M ammonium acetate, pH 4.5, at a flow rate of 0.30 mL/min to provide 4 min chromatograms. For a 250 microL plasma sample volume, the limit of quantitation was approximately 0.3 ng/mL. The calibration was linear from 0.30 to 98.0 ng/mL (r(2) > 0.995). A significant advantage of the method is the ability to employ parallel HPLC separations with detection by a single MS/MS system to provide sensitivity and selectivity sufficient to achieve robust analytical results with a lower limit of quantitation of 0.30 ng/mL and high throughput.
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PMID:High-throughput determination of atrasentan in human plasma by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. 1580 46

A promising liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) for analysis of the sulfates of 5alpha-androgen, androsterone and epiandrosterone (A-S and EpiA-S) in human serum was developed. The method was used to assess one of the markers of 5alpha-reductase activity of males including patients with prostate cancer (PC). After deproteinization with acetonitrile, the androgen sulfates and the internal standard, [7,7,16,16-2H4]dehydroepiandrosterone-S, were extracted from human serum using a solid-phase extraction cartridge and washed with hexane. The extract was reconstituted and applied to the LC/ESI-MS system operated in the selected ion monitoring mode. The method was validated over the range 0.02-5 microg/mL (A-S) and 0.005-1.5 microg/mL (EpiA-S) using 10 microL of human serum. The method was a concise procedure without chemical or enzymatic hydrolysis of the conjugates, purification by high-performance liquid chromatography and/or derivatization, and proved to be satisfactory in its reproducibility and accuracy. The levels of these androgen sulfates tended to decrease during aging, and the A-S levels in the sera obtained from both healthy males and patients with PC were correlated with their EpiA-S levels.
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PMID:Determination of sulfates of androsterone and epiandrosterone in human serum using isotope diluted liquid chromatography-electrospray ionization-mass spectrometry. 1595 57

A sensitive and selective LC-MS/MS method has been developed and validated for the quantification of abiraterone acetate and its metabolite, abiraterone (an androgen biosynthesis inhibitor) in human plasma. Analytes were extracted by SPE with cation mixed-mode polymer cartridges. Chromatography was performed on a Luna C5 5 microm, 50 mm x 2.1 mm i.d. column, using a mobile phase of 2% propan-2-ol in acetonitrile and 10mM ammonium acetate. The assay was linear from 5 to 500 nM (r(2)=0.998). The intra- and inter-day coefficients of variation were <13.9% for both analytes. This method will be applied to a clinical trial investigating the pharmacokinetics of abiraterone acetate and abiraterone in patients with prostate cancer.
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PMID:A validated liquid chromatographic-tandem mass spectroscopy method for the quantification of abiraterone acetate and abiraterone in human plasma. 1680 76

Improvement of the sensitivity and specificity of a simultaneous stress-free screening method for catechol estrogens as a potential prostate cancer marker in urine has been accomplished by HPLC with a diamond-electrode electrochemical detector and a fluorescence detector. Since taking urine samples generates less stress (or pain) than the drawing of blood, the method can readily be applied to almost any patient, and will also assist in improving the sensitivity and specificity of the prostatic specific antigen test. Catechol estrogens (2-hydroxyestrone, 4-hydroxyestrone, 2-methoxyestrone, 2-hydroxyestradiol, 4-hydroxyestradiol, 2-methoxyestradiol, and 2-hydroxyestriol) and estrogens (estrone, estradiol, estriol) were separated on an Inertsil ODS-II column with acetonitrile-potassium dihydrogen phosphate (pH 3.0). The diamond-electrode electrochemical detector used had the great advantage of being a maintenance-free system, and could sequentially analyze hundreds of samples. Fluorescence detection improved the sensitivity 10-500 times (e. g., the LOD of 2-hydroxyestriol was improved 250 times) compared to previous electrochemical detection reports, and dual detection improved peak identification in the urine samples. The proposed method was applied to the simultaneous determination of catechol estrogens in spiked urine in a preliminary study on estrogens and PSA values in biopsy and prostate cancer patients.
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PMID:HPLC for stress-free screening of potential prostate cancer marker catechol estrogens in urine using a diamond-electrode electrochemical and a fluorescence detector. 1766 12


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