Ultra-performance liquid chromatography/tandem mass spectrometry in high-throughput detection, quantification and confirmation of anabolic steroids in equine plasma

An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method for fast-throughput analysis of eight anabolic and androgenic steroids (AAS) in equine plasma is reported. Analytes were recovered by liquid-liquid extraction using methyl tert-butyl ether, separated on a 1.9 microm C(18) reversed-phase column, and analyzed in positive electrospray ionization mode on a triple quadrupole mass spectrometer with selected reaction monitoring (SRM) and full product ion scans. Two SRM ion transitions were monitored for each AAS during screening to obtain highly selective screening results. Full product ion spectra of excellent quality for AAS, at 100 pg/0.5 mL in plasma, devoid of interfering spectra from impurities in plasma, were obtained. To our knowledge, this is the first report on the acquisition of full product ion spectra at such a low analyte concentration and plasma volume using a triple quadrupole instrument. In addition to product ion intensity ratios obtained from three SRM scans for identifying AAS in equine plasma, full product ion spectra were used as supporting evidence for confirmation. For quantification, deuterium-labeled testosterone and stanozolol were used as internal standards (ISs). The limits of detection, quantification and confirmation were 6.25-12.5 pg/0.5 mL, 25 pg/0.5 mL and 50-100 pg/0.5 mL, respectively. There was no significant matrix effect on the analysis of all eight AAS. Intra-day precision and accuracy were 2-15% and 91-107%, respectively. Inter-day precision and accuracy were 1-21% and 94-110%, respectively. Total analysis time was 5 min. To date, the method has been successfully used in the analysis of >12,000 samples for AAS in plasma samples from racehorses competing in the State of Pennsylvania. The method is fast, selective, reproducible, and reliable.

Pharmacokinetics and effects of aminorex in horses

OBJECTIVE

To investigate the pharmacokinetics and behavioral effects of aminorex administered IV and PO in horses.

ANIMALS

7 Thoroughbreds.

PROCEDURES

In a cross-over design, aminorex (0.03 mg/kg) was administered IV or PO. Plasma and urinary aminorex concentrations were determined via liquid chromatography- mass spectrometry.

RESULTS

Decrease of aminorex from plasma following IV administration was described by a 3-compartment pharmacokinetic model. Median (range) values of alpha, beta, and gamma half-lives were 0.04 (0.01 to 0.28), 2.30 (1.23 to 3.09), and 18.82 (8.13 to 46.64) hours, respectively. Total body and renal clearance, the area under the plasma time curve, and initial volume of distribution were 37.26 (28.61 to 56.24) mL x min/kg, 1.25 (0.85 to 2.05) mL x min/kg, 13.39 (8.82 to 17.37) ng x h/mL, and 1.44 (0.10 to 3.64) L/kg, respectively. Oral administration was described by a 2-compartment model with first-order absorption, elimination from the central compartment, and distribution into peripheral compartments. The absorption half-life was 0.29 (0.12 to 1.07) hours, whereas the beta and gamma elimination phases were 1.93 (1.01 to 3.17) and 23.57 (15.16 to 47.45) hours, respectively. The area under the curve for PO administration was 10.38 (4.85 to 13.40) ng.h/mL and the fractional absorption was 81.8% (33.8% to 86.9%).

CONCLUSIONS AND CLINICAL RELEVANCE

Aminorex administered IV had a large volume of distribution, initial rapid decrease, and an extended terminal elimination. Following PO administration, there was rapid absorption, rapid initial decrease, and an extended terminal elimination. At a dose of 0.03 mg/kg, the only effects detected were transient and central in origin and were observed only following IV administration.

Biomarkers of alcohol abuse in racehorses by liquid chromatography/tandem mass spectrometry

A rapid and sensitive method was developed for the screening, quantification and confirmation of ethyl glucuronide (EG) and ethyl sulfate (ES) as biomarkers for alcohol administration to racehorses using liquid chromatography coupled on-line with triple quadrupole tandem mass spectrometry. Urine sample aliquots (0.1 mL) were pre-treated by protein precipitation. Separation of EG and ES was achieved on an Ultra PFP column. Isocratic elution with a flush step was performed using 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). Analysis was performed by negative electrospray ionization in multiple reaction monitoring mode. The retention times for EG and ES were 1.7 +/- 0.30 and 3.4 +/- 0.30 min, respectively. The internal standard used was d(5)-ethyl glucuronide with a retention time of 1.7 +/- 0.30 min. The entire separation was completed in <5 min. The limit of detection (LOD) and of quantification (LOQ) for both analytes were 100 ng/mL (S/N > or =3) and 500 ng/mL, respectively. The limit of confirmations (LOC) for EG and ES were 500 ng/mL and 1.0 microg/mL, respectively. The assay was linear over a concentration range of 0.5-100 microg/mL (r(2) > 0.995). Intra- and inter-day accuracy and precision were less than 15%. The analytes were stable in urine for 24 h at room temperature, 10 days at 4 degrees C and 21 days at -20 degrees C and -70 degrees C. Ion suppression or enhancement due to matrix effect was negligible. The measurement uncertainty was <14% for EG and <25% for ES. This method was successfully used for the quantification of EG and ES in urine samples following alcohol administration to research horses and for screening and confirmation of EG and ES in urine samples obtained from racehorses post-competition. The method is simple, rapid, inexpensive, and reliably reproducible.

Resolution, quantification and confirmation of betamethasone and dexamethasone in equine plasma by liquid chromatography/tandem mass spectrometry

This method describes the simultaneous separation, identification, quantification and confirmation of betamethasone (BTM) and dexamethasone (DXM) in equine plasma by liquid chromatography (LC) integrated with multidimensional tandem mass spectrometry. Analytes were directly extracted from equine plasma by methyl tert-butyl ether (MTBE). The residues were reconstituted with sample solvent. LC separation of the analytes was performed on a Hypercarb column using acetonitrile/water/formic acid (95:5:0.5, v/v/v) as the mobile phase. Sample screening, quantification and confirmation were performed in multiple reaction monitoring (MRM) mode. The method was linear over the concentration range of 0.1-75 ng/mL for both analytes. Limit of detection (LOD) was 50 pg/mL and that of quantification (LOQ) was 100 pg/mL for both analytes. The limit of confirmation (LOC) for the presence of BTM or DXM by MRM was 0.5 ng/mL. The intra-and inter-day precisions expressed as coefficient of variation (CV) for quantification of DXM and BTM from 0.1 to 50 ng/mL were less than 7% and the accuracy was in the range of 97-105%. This method is capable of distinguishing BTM from DXM when both analytes are simultaneously present in equine plasma. Measurement uncertainty for both analytes was estimated at less than 16%. The method is rapid, specific, selective, sensitive, simple and reliable. The importance of this method is its usefulness in directly identifying and differentiating BTM from DXM without derivatization.

Simultaneous analysis of twenty-one glucocorticoids in equine plasma by liquid chromatography/tandem mass spectrometry

A method for the simultaneous separation, identification, quantification and confirmation of the presence of 21 glucocorticoids (GCC) in equine plasma by liquid chromatography coupled with triple stage quadrupole tandem mass spectrometry (LC/TSQ-MS/MS) is described. Plasma sample augmented with the 21 GCC was extracted with methyl tert-butyl ether (MTBE) and analyzed by positive electrospray ionization. Desoxymetasone or dichlorisone acetate was used as the internal standard (IS). Quantification was performed by IS calibration. For each drug, one major product ion was chosen and used for screening for that drug. Analyte confirmation was performed by using the three most intense product ions formed from the precursor ion and the corresponding mass ratios. The recovery of the 21 GCC when spiked into blank plasma at 5 ng/mL was 45-200% with coefficient of variation (CV) from 0.3-18%. The limit of detection (LOD) and that of quantification (LOQ) for most of the analytes were 50-100 pg/mL and 1 ng/mL, respectively, whereas that of confirmation (LOC) was 100-300 pg/mL depending on the analyte. Intra- and inter-day precisions expressed as CV for quantification of 1 and 10 ng/mL was 1.0-17%, and 0.51-19%, respectively, and the accuracy was from 84-110%. The linear concentration range for quantification was 0.1-100 ng/mL (r(2) > 0.997). Estimated measurement uncertainty was from 11-37%. This study was undertaken to develop a method for simultaneous screening, identification, quantification and confirmation of these agents in post-race equine plasma samples. The method has been successfully applied to screening of a large number of plasma samples obtained from racehorses in competition and in pharmacokinetic studies of dexamethasone in the horse and concurrent changes in endogenous GCC, hydrocortisone and cortisone. The method is simple, sensitive, selective and reliably reproducible.

Pharmacokinetics and disposition of clenbuterol in the horse

The pharmacokinetics of clenbuterol (CLB) following a single intravenous (i.v.) and oral (p.o.) administration twice daily for 7 days were investigated in thoroughbred horses. The plasma concentrations of CLB following i.v. administration declined mono-exponentially with a median elimination half-life (t(1/2k)) of 9.2 h, area under the time-concentration curve (AUC) of 12.4 ng.h/mL, and a zero-time concentration of 1.04 ng/mL. Volume of distribution (V(d)) was 1616.0 mL/kg and plasma clearance (Cl) was 120.0 mL/h/kg. The terminal portion of the plasma curve following multiple p.o. administrations also declined mono-exponentially with a median elimination half-life (t(1/2k)) of 12.9 h, a Cl of 94.0 mL/h/kg and V(d) of 1574.7 mL/kg. Following the last p.o. administration the baseline plasma concentration was 537.5 +/- 268.4 and increased to 1302.6 +/- 925.0 pg/mL at 0.25 h, and declined to 18.9 +/- 7.4 pg/mL at 96 h. CLB was still quantifiable in urine at 288 h following the last administration (210.0 +/- 110 pg/mL). The difference between plasma and urinary concentrations of CLB was 100-fold irrespective of the route of administration. This 100-fold urine/plasma difference should be considered when the presence of CLB in urine is reported by equine forensic laboratories.

Quantification and confirmation of flunixin in equine plasma by liquid chromatography–quadrupole time-of-flight tandem mass spectrometry

The method describes quantification and confirmation of flunixin in equine plasma by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC/Q-TOF/MS/MS). Samples were screened by enzyme-linked immunosorbent assay (ELISA) and only those samples presumptively declared positive were subjected to quantification and confirmation for the presence of flunixin by this method. The method is also readily adaptable to instrumental screening for the analyte. Flunixin was recovered from plasma by liquid-liquid extraction (LLE). The sample was diluted with 2 ml saturated phosphate buffer (pH 3.10) prior to LLE. The dried extract was reconstituted in acetonitrile:water:formic acid (50:50:0.1, v/v/v) and subsequently analyzed on a Q-TOF tandem mass spectrometer (Micromass) operated under electrospray ionization positive ion mode. The concentration of flunixin was determined by the internal standard (IS) calibration method using the peak area ratio with clonixin as the IS. The limits of detection (LOD) and quantification (LOQ) for flunixin in equine plasma were 0.1 and 1 ng/ml, respectively, whereas the limit of confirmation (LOC) was 2.5 ng/ml. The qualifying ions for the identification of flunixin were m/z 297 [M+H](+), 279 (BP), 264, 259, 239 and those for clonixin (IS) were m/z 263 [M+H](+), 245 (BP) and 210. The measurement uncertainty about the result was 8.7%. The method is simple, sensitive, robust and reliably fast in the quantification and confirmation of flunixin in equine plasma. Application of this method will assist racing authorities in the enforcement of tolerance plasma concentration of flunixin in the racehorse on race day.

Quantification of clenbuterol in equine plasma, urine and tissue by liquid chromatography coupled on-line with quadrupole time-of-flight mass spectrometry

Clenbuterol (CBL) is a potent beta(2)-adrenoceptor agonist used for the management of respiratory disorders in the horse. The detection and quantification of CBL can pose a problem due to its potency, the relatively low dose administered to the horse, its slow clearance and low plasma concentrations. Thus, a sensitive method for the quantification and confirmation of CBL in racehorses is required to study its distribution and elimination. A sensitive and fast method was developed for quantification and confirmation of the presence of CBL in equine plasma, urine and tissue samples. The method involved liquid-liquid extraction (LLE), separation by liquid chromatography (LC) on a short cyano column, and pseudo multiple reaction monitoring (pseudo-MRM) by electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS). At very low concentrations (picograms of CBL/mL), LLE produced better extraction efficiency and calibration curves than solid-phase extraction (SPE). The operating parameters for electrospray QTOF and yield of the product ion in MRM were optimized to enhance sensitivity for the detection and quantification of CBL. The quantification range of the method was 0.013-10 ng of CBL/mL plasma, 0.05-20 ng/0.1 mL of urine, and 0.025-10 ng/g tissue. The detection limit of the method was 13 pg/mL of plasma, 50 pg/0.1 mL of urine, and 25 pg/g of tissue. The method was successfully applied to the analysis of CBL in plasma, urine and various tissue samples, and in pharmacokinetic (PK) studies of CBL in the horse. CBL was quantified for 96 h in plasma and 288 h in urine post-administration of CLB (1.6 micro g/kg, 2 x daily x 7 days). This method is useful for the detection and quantification of very low concentrations of CBL in urine, plasma and tissue samples.

Disposition, elimination, and bioavailability of phenytoin and its major metabolite in horses

OBJECTIVE

To determine pharmacokinetics and excretion of phenytoin in horses.

ANIMALS

6 adult horses.

PROCEDURE

Using a crossover design, phenytoin was administered (8.8 mg/kg of body weight, IV and PO) to 6 horses to determine bioavailability (F). Phenytoin also was administered orally twice daily for 5 days to those same 6 horses to determine steady-state concentrations and excretion patterns. Blood and urine samples were collected for analysis.

RESULTS

Mean (+/- SD) elimination half-life following a single IV or PO administration was 12.6+/-2.8 and 13.9+/-6.3 hours, respectively, and was 11.2+/-4.0 hours following twice-daily administration for 5 days. Values for F ranged from 14.5 to 84.7%. Mean peak plasma concentration (Cmax) following single oral administration was 1.8+/-0.68 microg/ml. Steady-state plasma concentrations following twice-daily administration for 5 days was 4.0+/-1.8 microg/ml. Of the 12.0+/-5.4% of the drug excreted during the 36-hour collection period, 0.78+/-0.39% was the parent drug phenytoin, and 11.2+/-5.3% was 5-(phydroxyphenyl)-5-phenylhydantoin (p-HPPH). Following twice-daily administration for 5 days, phenytoin was quantified in plasma and urine for up to 72 and 96 hours, respectively, and p-HPPH was quantified in urine for up to 144 hours after administration. This excretion pattern was not consistent in all horses.

CONCLUSIONS AND CLINICAL RELEVANCE

Variability in F, terminal elimination-phase half-life, and Cmax following single or multiple oral administration of phenytoin was considerable. This variability makes it difficult to predict plasma concentrations in horses after phenytoin administration.

Quantification of phenytoin and its metabolites in equine plasma and urine using high-performance liquid chromatography

A reliable and sensitive method for the extraction and quantification of phenytoin (5,5'-diphenylhydantoin), its major metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) and minor metabolite, 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) in horse urine and plasma is described. The method involves the use of solid-phase extraction (SPE), liquid-liquid extraction (LLE), enzyme hydrolysis (EH) and high-performance liquid chromatography (HPLC). The minor metabolite, 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) was not present in a reliably quantifiable concentration in all samples. The new method described was successfully applied in the pharmacokinetic studies and elimination profile of phenytoin and p-HPPH following oral or intravenous administration in the horse.

Pharmacokinetics of penicillin G procaine versus penicillin G potassium and procaine hydrochloride in horses

OBJECTIVE

To compare the pharmacokinetics of penicillin G and procaine in racehorses following i.m. administration of penicillin G procaine (PGP) with pharmacokinetics following i.m. administration of penicillin G potassium and procaine hydrochloride (PH).

ANIMALS

6 healthy adult mares.

PROCEDURE

Horses were treated with PGP (22,000 units of penicillin G/kg of body weight, i.m.) and with penicillin G potassium (22,000 U/kg, i.m.) and PH (1.55 mg/kg, i.m.). A minimum of 3 weeks was allowed to elapse between drug treatments. Plasma and urine penicillin G and procaine concentrations were measured by use of high-pressure liquid chromatography.

RESULTS

Median elimination phase half-lives of penicillin G were 24.7 and 12.9 hours, respectively, after administration of PGP and penicillin G potassium. Plasma penicillin G concentration 24 hours after administration of penicillin G potassium and PH was not significantly different from concentration 24 hours after administration of PGP. Median elimination phase half-life of procaine following administration of PGP (15.6 hours) was significantly longer than value obtained after administration of penicillin G potassium and PH (1 hour).

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that i.m. administration of penicillin G potassium will result in plasma penicillin G concentrations for 24 hours after drug administration comparable to those obtained with administration of PGP Clearance of procaine from plasma following administration of penicillin G potassium and PH was rapid, compared with clearance following administration of PGP.

Disposition and excretion of 6-methoxy-2-naphthylacetic acid, the active metabolite of nabumetone in horses

OBJECTIVE

To examine, in horses, the disposition and excretion of the active metabolite 6-methoxy-2-naphthylacetic acid (6MNA) of the nonsteroidal anti-inflammatory prodrug nabumetone.

DESIGN

Pharmacokinetic analysis of 6MNA after oral administration of nabumetone and IV administration of 6MNA.

PROCEDURE

Using a crossover design, 5 horses were orally administered 3.7 mg of nabumetone/kg of body weight. After a 3-week washout period, 4 horses were administered 2.5 mg of 6MNA/kg, IV.

RESULTS

Absorption of nabumetone from the gastrointestinal tract and its metabolism to 6MNA had a median appearance half-life of 0.88 hour. The elimination half-life was 11 hours. Area under the plasma concentration time curve for 6MNA after oral administration of nabumetone was 120.6 mg/h/L. A dose of 2.5 mg/kg of 6MNA administered IV resulted in plasma concentration nearly equivalent to that induced by the orally administered dose. Disposition of 6MNA was modeled as a one-compartment, first-order elimination. The area under the plasma concentration time curve for IV administration of 6MNA was 117.0 mg/h/L, and the specific volume of distribution was 0.247 L/kg. The distribution half-life and the elimination half-life were 0.56 and 7.90 hours, respectively. Percentage of total dose recovered in urine for the 36-hour collection period after the oral and IV administrations was 7.4 and 5.3%, respectively.

CONCLUSIONS

Metabolism of nabumetone to 6MNA, as reported in other species, also occurs in horses. There were a number of additional metabolites of nabumetone in urine that could not be fully identified and characterized.

Postmortem tissue samples: an alternative to urine and blood for drug analysis in racehorses

Although urine is the sample of choice for drug tests in racehorses, it is rarely obtained following the sudden death of a racehorse on the track while racing. The purpose of this study was to demonstrate the significance of postmortem tissue samples as an alternative to urine and blood samples in equine drug analysis following the sudden death of a racehorse on the track while participating in a competitive race. Postmortem tissue samples were frozen (-80 degrees C) until analyzed. A 30-40-g portion of each organ was homogenized in a 0.1 M phosphate buffer (pH 7.4), deproteinized, hydrolyzed with beta-glucuronidase, extracted, and screened by thin-layer chromatography and immunoassay. Samples that initially tested positive for drug(s) were then extracted using high-flow, solid-phase extraction cartridges. The eluates were analyzed by gas chromatography-mass spectrometry. The presence of butorphanol in horses HB355 and CD387, pentobarbital in horse HO940, and ergotamine in horses HO940 and CD387 was detected and confirmed. Thus, in the absence of urine and blood samples following sudden death, postmortem tissue samples are equally useful for forensic toxicological investigations of racehorses.

Plasma and synovial fluid kinetics, disposition, and urinary excretion of naproxen in horses

Naproxen (+6-methoxy-[alpha-methyl]-2-naphthalene acetic acid) is a nonsteroidal anti-inflammatory drug that is used for the treatment of inflammatory conditions in horses. We developed a model that describes the drug's disposition and renal excretion, including synovial fluid disposition and elimination after IV administration in horses. The plasma disposition, after IV administration of 5 mg/kg of body weight, was described by a two-compartment model; mean +/- SD distribution and elimination half-lives were 1.42 +/- 0.42 and 8.26 +/- 2.56 hours, respectively. Plasma concentration of naproxen after IV administration of 5 mg/kg was 55.3 +/- 13.5 and 0.61 +/- 0.42 mg/L at 5 minutes and 48 hours after its administration, respectively. Steady-state volume of distribution was 0.163 +/- 0.053 L/kg, and area under the plasma concentration time-curve was 372.1 +/- 128.2 mg/h/L. The peak synovial fluid concentration of 12.68 +/- 12.39 mg/L was measured at 6 hours, and decreased to 0.71 +/- 0.38 mg/L at 36 hours after naproxen administration. The decrease of naproxen concentration in synovial fluid paralleled that in plasma. The appearance half-life of naproxen in synovial fluid was 4.64 hours, and the elimination half-life was 6.73 hours. Total body clearance was 0.015 +/- 0.006 L/h/kg. The percentage of plasma protein binding was 97.0 +/- 2.9% at plasma concentrations between 5 and 100 mg/L. This was significantly (P < 0.05) higher than the percentage of binding at plasma concentrations of 0.5, 1, and 500 mg/L, which was 75.2 +/- 11.8%. Most of the drug was excreted as glucuronidated naproxen and unconjugated desmethylnaproxen.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma concentration of furosemide versus specific gravity of urine in predicting dose of administration in race horses

This study was undertaken to determine the applicability of plasma concentration of furosemide and specific gravity (SG) of urine in regulating the use of furosemide administered 4 hours prior to race time in Exercise-Induced Pulmonary Hemorrhage (EIPH) race horses. Nonbleeders (CTL) and certified bleeders (FUR) actively racing in Illinois (IL) and Pennsylvania (PA) were used in the study. Various doses (less than 250, 250, 300, 350, 400 and 500 mg) were administered either as a single intravenous (IV) dose or as a combination (IV-IM) of IV and intramuscular (IM) administrations 4 hours before race time. Plasma and urine samples were obtained post race for determination of furosemide concentration in plasma and measurement of SG of the urine in both CTL and FUR groups. Plasma samples were analyzed for furosemide using High Performance Liquid Chromatography with Fluorescence Detection. SG was measured using a digital refractometer. The results indicate a significant difference (p less than 0.0001) in the SG of the urine samples between the CTL and FUR groups irrespective of the route of administration (IV versus IV-IM). However, SG values of the urine in some CTL samples were lower than those in some FUR samples and vice versa. Thus, the use of SG alone is not reliable for predicting either the dose or the administration of furosemide to race horses. The plasma concentrations of furosemide following the administration (IV) of 250 mg or 500 mg 4 hours prior to race time were indistinguishable (25.91 +/- 4.45 versus 28.12 +/- 6.99 ng/ml, respectively); the majority of the horses in the groups had a plasma concentration of less than 40 ng/ml. When taken in total, plasma concentration of furosemide can only be used as a guide in regulating the administration of furosemide to race horses.

Characterization of bromhexine and ambroxol in equine urine: effect of furosemide on identification and confirmation

The purpose of this study was two-fold: (1) to develop a simple and sensitive screening procedure for identifying and confirming bromhexine and ambroxol and, (2) to determine the effect of furosemide on the detection of bromhexine, ambroxol, or their metabolites in urine. Female horses (450-550 kg) treated with bromhexine or ambroxol (1 g, p.o.) were used. Urine samples were collected up to 48 h post-drug administration and analysed. Blind samples were used in evaluating the sensitivity of these methods and reproducibility of the results. Bromhexine and ambroxol were extensively metabolized in the horse. These agents and their respective metabolites were identified and confirmed using thin-layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS), respectively. Hydroxy-bromhexine and desmethyl-bromhexine were major metabolites found to be unique to bromhexine-treated horses. These metabolites selectively absent from ambroxol-treated horse urine provide a chemical means to distinguish bromhexine from ambroxol administration in horses. These specific metabolites were similarly identified and confirmed in "blind" horse urine samples. The concomitant presence of furosemide (300 mg, i.v.) with bromhexine or ambroxol did not mask the presence of these agents or alter their metabolite profile. By application of the methods described in this study, bromhexine and ambroxol metabolites in horse urine can be easily identified and confirmed.

Initial features and prognosis in 363 children with acute lymphocytic leukemia

The relationship of a variety of initial features and the outcome of therapy was analyzed for 363 children with acute lymphocytic leukemia (ALL). All had entered "total therapy" studies between 1962 and 1971. The standard for comparing outcome of therapy was whether patients with a given feature attained or exceeded the median duration of complete remission, hematologic remission or survival for the group. The results showed that, in general, the more massive or extensive the disease at diagnosis, the poorer the outcome. Factors associated with a significantly poorer prognosis included: initial leukocyte count above 100,000/mm; spleen enlargement greater than 5 cm; mediastinal involvement and early CNS involvement. Children over 10 years old at diagnosis and Negro children also had a poor prognosis. From another viewpoint features were examined for patients who attained at least 3 years of continuous complete remission. This confirmed some earlier findings and, in addition, showed that children under 2 years of age at diagnosis or with hepatomegaly over 5 cm were less likely to attain this goal. With the exception of early CNS involvement, however, patients with excellent responses to therapy were found with each factor of poor prognosis. Two major factors were not analyzed because their relationship to prognosis is generally accepted: therapeutic differences and acute nonlymphocytic leukemia.