RESUMEN

ABT-384 is a potent, selective inhibitor of 11-beta-hydroxysteroid dehydrogenase type 1 (HSD-1). One milligram of ABT-384 daily fully inhibited hepatic HSD-1. Establishing the dose that fully inhibits central nervous system (CNS) HSD-1 would enable definitive clinical studies in potential CNS indications. [9,11,12,12-(2)H4] cortisol (D4 cortisol), a stable labeled tracer, was used to characterize HSD-1 inhibition by ABT-384. D4 cortisol and its products were measured in the plasma and cerebrospinal fluid (CSF) of healthy male volunteers during D4 cortisol infusions, for up to 40 h after five daily doses of 1-50 mg ABT-384. Similar procedures were conducted in control subjects who received no ABT-384. Peripheral HSD-1 inhibition was calculated from plasma levels of D4 cortisol and its products. CNS HSD-1 inhibition was characterized from plasma and CSF levels of D4 cortisol and its products. ABT-384 regimens ≥2 mg daily maintained peripheral HSD-1 inhibition ≥88%. ABT-384 1 mg daily maintained peripheral HSD-1 inhibition ≥81%. No CNS formation of D3 cortisol (the mass-labeled product of HSD-1) was detected following ABT-384 ≥2 mg daily, indicating full CNS HSD-1 inhibition by these regimens. Partial CNS HSD-1 inhibition was associated with 1 mg ABT-384 daily. CNS HSD-1 inhibition was characterized by strong hysteresis and increased with maximum post-dose plasma concentration of ABT-384 and its active metabolites. ABT-384 has a wide potential therapeutic window for potential indications including Alzheimer's disease and major depressive disorder. Stable labeled substrates may be viable tools for measuring CNS effect during new drug development for other enzyme targets.

Asunto(s)

RESUMEN

A liquid chromatographic/tandem mass spectrometric (LC/MS/MS) assay for the quantitative analysis of the novel anticancer drug ABT-518 and the screening of six potential metabolites in human plasma has been developed and validated to support a phase I study with the drug. ABT-518 is an inhibitor of matrix metalloproteinases, which are associated with tumor growth and development of metastasis. Plasma samples were prepared for analysis using a simple solid-phase extraction method on phenyl cartridges. LC separation was performed on a Zorbax extend C18 column (150 x 2.1 mm i.d., 5 microm particle size) using a mobile phase of methanol-aqueous 10 mM ammonium hydroxide (80:20, v/v) pumped at a flow-rate of 0.2 ml min(-1). An API2000 triple-quadrupole mass spectrometer was used for specific and sensitive detection. The best chromatographic speed (total run time 8 min) and peak shapes were obtained by employing an alkaline mobile phase (pH in aqueous phase approximately 10). Furthermore, an alkaline eluent was favored in order to obtain a better overall sensitivity for the protonated analytes. The dynamic range was from 10 to 1000 ng ml(-1) from 500 microl of plasma for ABT-518 and the metabolites were detected at levels of the same order of magnitude. Inter-assay accuracies for ABT-518 at five concentration levels were between -9.24 and 6.93% and inter-assay precisions were always <10.7%. Analyte stability was not critical during either storage or processing. This method was successfully applied in a phase I clinical study of ABT-518. The active drug, ABT-518, and all of the metabolites included in the assay could be identified in plasma from dosed patients. We believe that the method described in this paper using an alkaline mobile phase in combination with a basic stable analytical column may also be generally useful for the bioanalysis of other basic drugs.

Asunto(s)

RESUMEN

This study was conducted to evaluate the potential pharmacokinetic interaction between fenofibrate and pravastatin. A total of 23 healthy adult volunteers received single-dose 201 mg fenofibrate alone, 201 mg fenofibrate + 40 mg pravastatin, and 40 mg pravastatin alone in a three-period crossover experiment. Plasma samples were collected at predetermined times and were analyzed with validated methods for the quantitation of fenofibric acid, pravastatin, and 3 alpha-hydroxy-isopravastatin (3 alpha-iso-PV). Pharmacokinetic parameters of these three compounds were calculated using noncompartmental methods and compared by analyses of variance and bioavailability assessments. Concomitant administration of fenofibrate and pravastatin did not affect the pharmacokinetics of either fenofibric acid or pravastatin. However, the AUC0-infinity and Cmax of 3 alpha-iso-PV were increased by 26% and 29%, respectively. The moderate increase in the formation of this pravastatin metabolite should not raise any clinical concerns due to its much lower pharmacological potency compared to pravastatin and lack of toxicity.

Asunto(s)

RESUMEN

Bioactivity-directed fractionation of the seeds of Annona muricata L. (Annonaceae) resulted in the isolation of five new compounds: cis-annonacin (1), cis-annonacin-10-one (2), cis-goniothalamicin (3), arianacin (4), and javoricin (5). Three of these (1-3) are among the first cis mono-tetrahydrofuran ring acetogenins to be reported. NMR analyses of published model synthetic compounds, prepared cyclized formal acetals, and prepared Mosher ester derivatives permitted the determinations of absolute stereochemistries. Bioassays of the pure compounds, in the brine shrimp test, for the inhibition of crown gall tumors, and in a panel of human solid tumor cell lines for cytotoxicity, evaluated relative potencies. Compound 1 was selectively cytotoxic to colon adenocarcinoma cells (HT-29) in which it was 10,000 times the potency of adriamycin.

Asunto(s)

RESUMEN

A novel acetogenin, asiminocin (1), was isolated by activity-directed fractionation from the stem bark of the paw paw tree, Asimina triloba. By spectral and chemical methods, 1 was identified as (30S)-hydroxy-4-deoxyasimicin. The absolute configuration of 1, along with those of previously reported acetogenins asimin, asiminacin, bullatin, (30S)-bullanin, and (30R) bullanin, was determined by Mosher ester methodology. Compound 1 was highly inhibitory to three human solid tumor cell lines with over a billion times the potency of adriamycin.

Asunto(s)

RESUMEN

In continuing our research with cytotoxic and pesticidal components from the stem bark of the North American paw paw, Asimina triloba, the novel cytotoxic monotetrahydrofuran Annonaceous acetogenins, cis- and trans-annonacin-A-one, cis- and trans-gigantetrocinone and cis-isoannonacin, in addition to the known compounds, trans-isoannonacin and squamolone, have been identified. Brine shrimp lethality testing was used to direct the fractionation. The structures were elucidated by spectral analysis and/or chemical synthesis. These acetogenins have potent cytotoxicities against the human tumour cell lines of A-549 (lung carcinoma), MCF-7 (breast carcinoma) and HT-29 (colon adenocarcinoma).

Asunto(s)

RESUMEN

The relative stereochemistries of bullatalicin [1] and bullatalicinone [2] were partially reassigned based on COSY and relayed COSY spectra. The structures of annonins VIII [3], IV [4], and XVI [5] were revised and concluded as bullatalicin [1], bullatanocin [6], and squamostatin A [7], respectively.

Asunto(s)

Asunto(s)

RESUMEN

A case of a patient with an acute anterior myocardial infarction (MI) and ventricular fibrillation is presented. The patient was resuscitated after cough-cardiopulmonary resuscitation (C-CPR) was administered in the emergency department. The patient received thrombolytic therapy without complication. Cough-CPR is a technique not in widespread use. With the advent of thrombolytic therapy for patients with acute myocardial infarctions, a relative contraindication to thrombolytic therapy is present in patients who receive "standard CPR." The use of cough-CPR in witnessed dysrhythmias can alleviate this problem. Cough-CPR can also reduce the morbidity of resuscitations.

Asunto(s)