Towards establishing MS prevalence in Latin America and the Caribbean.

A very high prevalence of multiple sclerosis (MS) has been reported in some Western European and North American countries. The few surveys of MS epidemiology in South America reveal lower prevalence rates, implying that susceptibility varies between distinct ethnic groups, thus forming an important determinant of the geographic distribution of the disease. The objective of this study is to review MS prevalence estimates in different Latin American and Caribbean countries. We reviewed surveys of regional MS prevalence from 1991 to 2011. Sources included an online database, authors' reports and proceedings or specific lectures from regional conferences. We obtained a total of 30 prevalence surveys from 15 countries, showing low/medium MS prevalence rates. Both the number and the quality of prevalence surveys have greatly improved in this region over recent decades. This is the first collaborative study to map the regional frequency of MS. Establishment of standardized methods and joint epidemiological studies will advance future MS research in Latin America and the Caribbean.

What can we really tell women with multiple sclerosis regarding pregnancy? A systematic review and meta-analysis of the literature.

BACKGROUND: Although several papers report on pregnancy and multiple sclerosis (MS), no systematic review of the literature has been carried out. Neurologists and obstetricians need to have proper information to discuss with women presenting with MS who consider pregnancy. OBJECTIVES: Literature review and meta-analysis of data on pregnancy in women with MS. SEARCH STRATEGY: The present work followed the recommendations of the PRISMA Statement. Using the PICO framework, the authors independently searched for the terms 'pregnancy' OR 'gestation' OR 'pregnant' AND 'multiple sclerosis' OR 'MS' in the following databases: EMBASE/Excerpta Medica, Medline, Pubmed, Scopus, Index Medicus, Biomed Central, Ebsco Fulltext, LILACS, Scielo and the Cochrane Database of Systematic Reviews. SELECTION CRITERIA: only papers presenting original work with analysis of at least one of the outcomes among pregnant women with MS were included. DATA COLLECTION AND ANALYSIS: Two independent workers performed the literature review. All the authors selected and read the relevant papers. Two other authors summarised data for analysis. MAIN RESULTS: Twenty-two papers reporting on 13,144 women with MS and their pregnancies were analysed. A significant decrease in relapse rate was observed during pregnancy, followed by a significant increase after delivery. Miscarriages, low birthweight, prematurity, neonatal death and malformations were assessed among these women and their offspring. There seems to be a regional influence on the rates of caesarean sections and abortions among women with MS. Neonatal death and malformation rates did not seem to be particularly high. AUTHORS' CONCLUSIONS: The present work provides evidence-based data that can be discussed with women with MS and their relatives when pregnancy is considered by these families.

The Brazilian database on pregnancy in multiple sclerosis.

OBJECTIVES: To report the results from the Brazilian database on multiple sclerosis (MS) and pregnancy. METHODS: Retrospective data from MS patients who became pregnant at any time of their disease were sent to a Brazilian database, using a specific file for this purpose. RESULTS: Data on 128 women (142 pregnancies) from 30 neurologists working in 21 cities in Brazil were collected. Patients' average age at pregnancy was 29.8 years (range 16-42). EDSS at start of pregnancy was 1.5±1.4; and the relapse rate in the year preceding pregnancy was 1.2±1.5. Exposure to medication at any time during pregnancy was high (69.7%): 48.6% to interferon beta; 14.1% to glatiramer acetate; and 7% to other immunomodulatory and immunosuppressive drugs. There was a significant decrease in relapse rate during pregnancy. The prevalence of complications was relatively low, with 4.9% of obstetric and 1.4% neonatal unfavorable outcomes. CONCLUSIONS: Our patients had low degrees of disability, short histories of disease, high drug exposure, and relatively high relapse rate in the year previous to pregnancy. Obstetric and neonatal outcomes were successful in over 90% of our patients.

Detection of tuberculostearic acid in serum and other biological fluids from patients with tuberculosis by electron capture-gas chromatography and chemical ionisation-mass spectrometry.

We analysed 37 clinical samples from 33 patients with bacteriologically confirmed tuberculosis, two cerebrospinal fluid samples from patients with cured tuberculous meningitis, and 14 serum samples from healthy individuals, for the presence of tuberculostearic acid (TSA) by frequency pulsed electron capture-gas chromatography (FPEC-GC) and chemical ionisation gas chromatography-mass spectrometry (CIGC-MS). TSA was detected in 36 of the 37 samples from patients with active tuberculosis and none of the patients with cured tuberculous meningitis; only one of 14 controls generated a similar chromatographic profile. Analysis of biological fluids by FPEC-GC and CIGC-MS for the presence of TSA may be a valuable method for rapid diagnosis of tuberculosis.

Electron-capture gas chromatographic-chemical ionization mass spectrometric study of sera from people vaccinated with bacille Calmette-Guerin for characteristic metabolites.

Serum samples from 26 individuals vaccinated with bacille Calmette-Guerin (BCG) and from 26 controls (10 patients with pulmonary tuberculosis and 16 non BCG-vaccinated healthy individuals) were analyzed by frequency-pulsed electron-capture gas chromatography (FPEC-GC) and chemical ionization gas chromatography-mass spectrometry (CIGC-MS) for the presence of characteristic metabolites. A distinct pattern consisted of tuberculostearic acid (TSA) and a peak, labeled peak 1, was observed in all BCG-vaccinated individuals, whereas only three of 26 controls generated this chromatography profile. TSA was detected in all patients with pulmonary tuberculosis but peak 1 was absent. Sera drawn from 12 individuals 11 to 14 days after BCG vaccination yielded three transitional FPEC-GC profiles. A permanent FPEC-GC profile consisting of TSA and of a full scale peak 1 appeared 28 days to a few months after BCG vaccination. Peak 1 was tentatively identified by CIGC-MS as 9-methyl-hexacosanol. The findings suggest that peak 1 may serve as a marker to detect Mycobacterium bovis BCG and to distinguish individuals infected with M. tuberculosis from individuals vaccinated with BCG.

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.

Differentiation of sarcoidosis from tuberculosis by use of electron capture gas-liquid chromatography.

To explore further the possible etiologic role of mycobacteria in the development of sarcoidosis, we measured free, nonbound tuberculostearic acid (TSA, 10-methyloctadecanoic), a component of mycobacteria, in the sera of subjects with sarcoidosis or active untreated pulmonary tuberculosis and in healthy controls by use of frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). The selective analytic system is capable of measuring as little as 15-fmol quantities of free, nonbound TSA in serum and cerebral spinal fluid. We found that TSA was present in the sera of all subjects with Mycobacterium tuberculosis (n = 10) but was undetectable in subjects with sarcoidosis (n = 15) and in healthy controls (n = 15), thereby suggesting that if sarcoidosis is caused by a mycobacterial organism, TSA is not produced or does not gain access to the systemic circulation in quantities sufficient for measurement. However, in the course of the studies we found that a peak, designated p11, was elevated in the sera of all subjects with acute sarcoidosis (n = 4). Also, a peak designated p3 was reduced significantly in all subjects with acute and chronic sarcoidosis and absent in subjects with M. tuberculosis compared with healthy controls. Both peaks were later shown by chemical analysis and mass spectral studies to be carboxylic acids not previously associated with specific disease entities. Follow-up detailed studies will be needed to determine if quantitation of these unique carboxylic acids will be useful in differentiating sarcoidosis from other disorders.

Detection of malignancy-associated metabolites in the sera of cancer patients by electron capture gas chromatography.

A reliable test that detects malignancy and indicates response to therapy is needed. Frequency-pulsed electron-capture gas-liquid chromatography (FPEC-GLC), a selective analytical technique that is sensitive to 15 fmol quantities of metabolites, was used to analyse derivatised acidic chloroform extracts of sera from patients with biopsy-proven cancer, non-malignant infectious and non-infectious disease, and healthy controls. Two peaks designated P1 and P10, not found in serum from healthy controls (n = 7) or patients with non-malignant disease (n = 85), were detected in biopsy-proven samples (n = 52) from cancer patients. P1 and P10 were later shown by chemical and mass spectral studies to be carboxylic acids. When one or both of these peaks were detected in the sera of non-treated patients they were always associated with malignancy. In patients responding to therapy, a reduction or disappearance of these peaks was observed. Further, it was noted that P10 persisted or increased in sera of patients with progressive cancer not responding to therapy. We conclude that this test has potential in diagnosis and for following the response of the disease to therapy.

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%.

Analyses of fermentation products of Listeria species by frequency-pulsed electron-capture gas-liquid chromatography.

Aerobic fermentation broths of eight Listeria monocytogenes strains, two or more strains of the remaining six Listeria species, and one strain of Jonesia denitrificans were examined by frequency-pulsed electron-capture gas-liquid chromatography for carboxylic acids, alcohols, amines, and hydroxy acids. All species produced acetic, isobutyric, butyric, isovaleric, phenylacetic, lactic, 2-hydroxybutyric, 2-hydroxyvaleric, and 2-hydroxyisocaproic acids. Propionic acid was not formed, and traces of isocaproic acid were observed. Of the alcohol and amine derivatives observed, only acetylmethylcarbinol, butylamine, and putrecine were identified. Recognition of the products of glucose and amino acid metabolism serves to further characterize the members of the genus Listeria both taxonomically and physiologically.

Physiological studies on the growth and utilization of sugars by Listeria species.

Experiments, relevant to growth in milk, were done to delineate the aerobic and anaerobic growth of Listeria species on selected sugars in several media. All species grew on glucose aerobically, forming lactic acid and (or) acetic acid. Anaerobically, only lactic acid was formed; cell yields were 80% of those obtained aerobically. When incubated aerobically, small amounts (1.5 microns/mL) of isovaleric acid, 2-hydroxyisovaleric acid, and trace amounts of isobutyric acid were formed. These products were characteristically formed by 26 strains representing all the species of Listeria. Added leucine stimulated isovaleric acid formation. Anaerobic fermentations of glucose could be followed by 60 to 80% cell lysis; less lysis occurred in air. Anaerobically, only hexoses and pentoses supported growth; aerobically, maltose and lactose supported growth of some strains, but sucrose did not support growth of any strain tested. Listeria grayi and Listeria murrayi utilized the galactose and glucose moieties of lactose for growth; Listeria monocytogenes and Listeria innocua used only the glucose moiety. Glucosamine and N-acetylglucosamine supported aerobic and anaerobic growth as well as glucose, and their presence stimulated the utilization of lactose by "lactose-negative" strains. Analyses of cultures grown at 5 degrees C in sterile milk treated with glucose oxidase supported the conclusion that the glucose of the milk was the major, if not the limiting, substrate that supported growth.

Studies of metabolites in diarrheal stool specimens positive for Klebsiella, Serratia, and Proteus spp. by frequency-pulsed electron-capture gas chromatography.

Diarrheal stools from infants from which Klebsiella pneumoniae, Serratia liquefaciens, and Proteus mirabilis were isolated as possible causative agents of diarrhea were studied. These stools, along with control stool specimens which were collected from infants in the same village of Tamooh (near Cairo, Egypt), were analyzed by frequency-pulsed electron-capture gas chromatography (FPEC-GC). Watery stools and formed stools, to which distilled water was added, were centrifuged, and the supernatant was extracted with organic solvents and derivatized with specific functional group reagents to form electron-absorbing derivatives of carboxylic acids, hydroxy acids, alcohols, and amines. Results from the study showed distinct differences in FPEC-GC profiles of stools positive for K. pneumoniae, S. liquefaciens, and P. mirabilis. The major differences found were that diarrheal stools from which K. pneumoniae was isolated contained acetoin, a hydroxy acid-labeled peak F, and an unidentified amine, peak A. S. liquefaciens diarrheal stools had FPEC-GC profiles like the controls with the exception that an amine, peak A, was detected. The diarrhel stools containing P. mirabilis produced a distinct amine profile.

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.

Disposable reversed-phase chromatography columns for improved detection of carboxylic acids in body fluids by electron-capture gas-liquid chromatography.

Disposable reversed-phase chromatography columns were tested for their effectiveness in removing unreacted trichloroethanol (TCE) from derivatized samples for gas-liquid chromatography analysis. Derivatized acidic chloroform extracts of saponified whole cells of Mycobacterium species, spent culture media, and derivatized acidic chloroform extracts of serum and cerebrospinal fluids from patients with tuberculous meningitis were tested. Samples were added to preconditioned reversed-phase chromatography columns, and various solvents and solvent mixtures were tested to determine maximum recovery of the TCE derivatives. With this procedure, we were able to quickly remove the TCE reagent and efficiently recover TCE-derivatized carboxylic acids. Use of these columns improved the reagent cleanup procedure, simplified the derivatization step, permitted increased detection of trace components, such as tuberculostearic acid, in body fluids, and improved the selectivity of the procedure for detection of carboxylic acids.

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.

Frequency-pulsed electron-capture gas-liquid chromatographic studies of chemical changes in sera of patients with schistosomiasis.

Sera from well documented cases of Schistosoma mansoni and S. haematobium infections as well as controls, were studied by frequency-pulsed electron-capture gas--liquid chromatography (FPEL-GLC) and mass spectrometry for detection of carboxylic acids and amines. Many carboxylic acids and unidentified peaks were detected. In a few serum specimens from infected patients, putrescine and cadaverine were detected. Indications are that in these few patients with high egg counts enough diamines were present to possibly produce amine toxicity. Following the initial investigation, the basic chloroform extractions, which contained amines, were further studied by FPEC-GLC with the aid of splitless injection and a capillary column. Several amines were detected which seemed to be related to schistosomiasis. Mass spectra were obtained on an unidentified schistosamine peak. The possible significance of the data is discussed.

Studies of metabolites in diarrheal stool specimens containing Shigella species by frequency-pulsed electron capture gas-liquid chromatography.

Eleven diarrheal stool specimens and 10 control stool specimens from Cairo, Egypt, were studied by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). Four cases involving Shigella sonnei, three cases involving Shigella boydii, and four cases involving Shigella flexneri were studied. The aqueous stools were centrifuged, extracted with organic solvents, and derivatized to form specific electron-capturing derivatives of carboxylic acids, alcohols, hydroxy acids, and amines. Analyses were performed on high-resolution glass columns with an instrument equipped with an extremely sensitive electron capture detector that is specific for the detection of electron-capturing compounds. The diarrheal stools studied had specific FPEC-GLC profiles and contained metabolic markers that readily distinguished between the Shigella spp. studied and Escherichia coli producing heat-stable or heat-labile enterotoxins. S. sonnei stools contained hexanoic acid, 2-hydroxy-4-methylmethiobutyric acid, and some unidentified alcohols that distinguished this organism from other enteric pathogens. S. boydii produced an acid that was unique for this species, and S. flexneri produced alcohols that could be used to distinguish between it and other enteric organisms. The FPEC-GLC profiles obtained during this study were also very different from those reported earlier for Clostridium difficile and rotavirus. This study presents further evidence that the selectivity and sensitivity of FPEC-GLC techniques can be used to rapidly identify causative agents of diarrhea and detect physiological changes that occur in the gut during the course of diarrheal illness.

Rapid differentiation of enterotoxigenic Escherichia coli that produce heat-stable and heat-labile toxins by frequency-pulsed electron capture gas-liquid chromatography analysis of diarrheal stool specimens.

Thirty-three stool specimens from infants in the village of Tamooh near Cairo, Egypt, were studied by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). In 13 of the diarrheal cases, the suspected causative agent isolated was Escherichia coli which produced heat-stable toxin (ST), and in 10 other cases E. coli that produced heat-labile toxin (LT) were isolated. Ten control stool samples, collected from infants from whom no pathogenic organisms were isolated, were analyzed at the same time. Comparisons also were made against healthy control stools from individuals in the United States who had been previously analyzed by FPEC-GLC (Brooks et al., J. Clin. Microbiol. 20:549-560, 1984). The stools were suspended in water and centrifuged, and the supernatant was extracted with organic solvents and derivatized to form electron-capturing derivatives of carboxylic acids, hydroxy acids, alcohols, and amines. Results from the study showed distinct differences among the FPEC-GLC profiles of E. coli ST-positive stools, of E. coli LT-positive stools, and of the control stool samples. An unidentified compound appearing in the ether-soluble hydroxy acid fraction from E. coli ST-positive stools was tentatively identified by mass spectrometry as 6-methoxy-2-hydroxyhexanoic acid. 6-Methoxy-2-hydroxyhexanoic acid was found in all stools that contained E. coli ST but was not present either in stools from which E. coli LT was isolated or in control samples. 6-Methoxy-2-hydroxyhexanoic acid may prove to be an important marker for use in the identification of E. coli ST. In addition to 6-methoxy-2-hydroxyhexanoic acid, the carboxylic acid, alcohol, and amine FPEC-GLC profiles obtained from stools were very different between these two organisms. The data indicate that FPEC-GLC analysis of diarrheal stool specimens might be a rapid way to distinguish diarrhea caused by E. coli ST, E. coli LT, Clostridium difficile, and rotavirus.