Methotrexate-induced alterations in beta-oxidation correlate with cognitive abilities in children with acute lymphoblastic leukemia.

Treatment advances, including central nervous system (CNS) treatment with methotrexate, have led to significant gains in disease-free survival from childhood acute lymphoblastic leukemia (ALL). However, methotrexate has been associated with neurological problems such as declines in cognitive and academic abilities. The purpose of this study was to investigate methotrexate-induced changes in beta-oxidation in children with ALL receiving methotrexate for CNS treatment. Specific aims were to investigate effects of methotrexate on beta-oxidation of the two most prevalent fatty acids (palmitic acid and stearic acid) in cerebrospinal fluid (CSF) samples and correlate the ratio of monounsaturation to saturation of these fatty acids with cognitive and academic abilities. The sample included 12 females and 14 males with low-risk (n = 7), standard-risk ( n = 13), or high-risk (n = 6) ALL. Mean age at diagnosis was 94.1 months (SD = 34.4). CSF samples were obtained in conjunction with diagnostic lumbar punctures; subsequent samples were obtained prior to intrathecal methotrexate administration during the induction, consolidation, and continuation phases of treatment. Fatty acids were analyzed by gas chromatography. Results showed a significant increase in the ratio of monounsaturation to saturation of both fatty acids, which was greatest during the most intensive phase of treatment. Ratios of monounsaturated to saturated fatty acids were negatively correlated with full-scale IQ, verbal IQ, and math calculations. Findings suggest that methotrexate alters beta-oxidation and that the resulting increase in fatty acid monounsaturation is related to declines in some domains of cognitive ability.

Development of a quantitative chemical ionization gas chromatography-mass spectrometry method to detect tuberculostearic acid in body fluids.

We developed a mass spectral method to verify the detection of free tuberculostearic acid (TSA) by frequency-pulsed electron-capture gas chromatography (FPEC-GC) in cerebrospinal fluid (CSF), serum, pericardial fluid, ascites fluid and pleural fluid of patients infected with Mycobacterium tuberculosis. To obtain satisfactory sensitivity and specificity for comparison of the test using mass spectrometry (MS) in the single ion monitor (SIM) mode to the FPEC-GC test, we developed a specific, sensitive, quantitative chemical ionization mass spectrometry capillary gas chromatography (QCIGC-MS) test. The procedure maximized the molecular ion (i.e., made it the base peak) for increased specificity and sensitivity, and instrument parameters for increased sensitivity. The procedure uses a computerized approach, requiring an internal standard (nonadecanoic acid) for precise measurement of the retention time and quantitation of the molecular ion of TSA. Data from this study suggest that QCIGC-MS analysis could be a valuable tool to confirm FPEC-GC identification of TSA in CSF, serum, and in pleural, ascites, and pericardial fluids.

[Detection of tuberculostearic acid (TBSA) in CSF using gas chromatography in patients with tuberculous meningitis].

By using French's method TBSA in CSFs of 43 patients with tuberculous meningitis and 40 patients with non-tuberculous meningitis were performed. All the patients with tuberculous meningitis were positive and all the patients with non-tuberculous meningitis were negative. So the results showed that the method is a rapid, sensitive and accurate for diagnosis of tuberculous meningitis.

Rapid diagnosis of tuberculous meningitis by frequency-pulsed electron-capture gas-liquid chromatography detection of carboxylic acids in cerebrospinal fluid.

The frequency-pulsed electron-capture gas-liquid chromatography technique described previously by Brooks et al. was modified and applied to the studies of coded and routine clinical specimens. Uncentrifuged cerebrospinal fluid (2 ml) was extracted under acidic conditions, derivatized, and analyzed by frequency-pulsed electron-capture gas-liquid chromatography on large-bore fused silica polar and nonpolar capillary columns. The frequency-pulsed electron-capture gas-liquid chromatography profile of carboxylic acids (C2 through C22) along with identification of tuberculostearic acid, established by retention time comparison of derivatized tuberculostearic acid and derivatized sample extract, strongly suggests the presence of Mycobacterium tuberculosis in patients with lymphocytic meningitis. Results from 41 coded cases and 75 clinical cases showed that the frequency-pulsed electron-capture gas-liquid chromatography test had a specificity of 91% and a sensitivity of 95%.

The rapid and sensitive diagnosis of tuberculous meningitis by the detection of tuberculostearic acid in cerebrospinal fluid using gas chromatography-mass spectrometry with selective ion monitoring.

Tuberculostearic acid (10-Methyloctadecanoic acid) is a lipid component of the mycobacterial cell wall and its presence in cerebrospinal fluid can serve as a diagnostic marker for tuberculous meningitis. Using gas chromatography-mass spectrometry with selective ion monitoring, tuberculostearic acid (TBSA) was detected in nine different mycobacterial reference strains. Analysis of derivatised cerebrospinal fluid specimens from 35 patients showed the presence of TBSA in 5/6 culture-positive samples and 0/19 negative control patients (diagnosed as bacterial or viral meningitis). In addition 4/10 clinically suspected cases of tuberculous meningitis showed the presence of TBSA in the absence of other confirmatory laboratory results. A routine method has been developed for the detection of TBSA, which allows the fast and sensitive diagnosis of tuberculous meningitis within 5 h of receiving the cerebrospinal fluid specimen, compared to the 3 to 8 weeks required to culture the bacteria.

Selective procedures for detecting femtomole quantities of tuberculostearic acid in serum and cerebrospinal fluid by frequency-pulsed electron capture gas-liquid chromatography.

Conditions are described for the detection of tuberculostearic acid (10-methyloctadecanoate; C18 X CH3) in cerebrospinal fluid and serum of patients with tuberculous meningitis. C18 X CH3 was found in both the cerebrospinal fluid and serum of patients with tuberculous meningitis at concentrations of 25 to 50 fmol (10(-15) mol). The necessary specificity and sensitivity for detection of C18 X CH3 were obtained by extraction under acid conditions with organic solvent, specific functional group esterification with trichloroethanol, cleanup with disposable reverse-phase sorption chromatography columns, analysis on high-resolution polar and nonpolar capillary columns, and detection by a frequency-pulsed electron capture detector. Use of an IBM 9000 computer equipped with CAP software significantly aided comparison between known C18 X CH3 standards and C18 X CH3 in clinical specimens. Scale expansion and attenuation changes were the major contributions obtained by use of the computer. The data indicate that detection of C18 X CH3 by frequency-pulsed electron capture gas-liquid chromatography may be a valuable aid for early detection of tuberculous meningitis.

Detection of metabolites by frequency-pulsed electron capture gas-liquid chromatography in serum and cerebrospinal fluid of a patient with Nocardia infection.

Serum (SR) and cerebrospinal fluid (CSF) from a patient suspected of having tuberculous meningitis were submitted to our laboratory for analysis by frequency-pulsed electron capture gas-liquid chromatography (FPEC GLC). The samples were tested for the presence of carboxylic acids, alcohols, hydroxy acids, and amines by methods described previously (C. C. Alley, J. B. Brooks, and D. S. Kellogg, Jr., J. Clin. Microbiol. 9:97-102, 1977; J. B. Brooks, C. C. Alley, and J. A. Liddle, Anal. Chem. 46:1930-1934, 1974; J. B. Brooks, D. S. Kellogg, Jr., M. E. Shepherd, and C. C. Alley, J. Clin. Microbiol. 11:45-51, 1980; J. B. Brooks, D. S. Kellogg, Jr., M. E. Shepherd, and C. C. Alley, J. Clin. Microbiol. 11:52-58, 1980). The results were different from previous FPEC GLC profiles of SR and CSF from patients with known tuberculous meningitis. Both the SR and CSF contained several unidentified compounds that were not previously detected in tuberculous meningitis or any of our other studies of body fluids. Nocardia brasiliensis was later isolated from the patient. Detection of these metabolites by FPEC GLC could prove to be useful for rapid diagnosis of Nocardia disease, and their identification will provide a better understanding of metabolites produced by Nocardia sp. in vivo.