Biomedical subjects

J B Brooks

Publications and source records attributed to J B Brooks.

At least 37 records · Page 2Linked to original sources

PubMed1984

Frequency-pulsed electron capture gas-liquid chromatographic analysis of metabolites produced by Clostridium difficile in broth enriched with amino acids.

Clostridium difficile strain CDC A-567 was cultured in Trypticase (BBL Microbiology Systems)-yeast-salt broth supplemented with 0.2% L-leucine, L-norleucine, L-isoleucine, L-tyrosine, or L-tryptophan. Four extractions were done on the spent medium, three at pH 2 and one at pH 10, using CHCL3 or ether. Derivatizations were done with trichloroethanol, heptafluorobutyric anhydride, and heptafluorobutyric anhydride-ethanol. All samples were analyzed with frequency-pulsed electron capture gas-liquid chromatography. A dedicated computer was used to assist in data analysis. C. difficile produced both short-chain and aromatic acids in Trypticase-yeast-salt broth; hydroxy acids were also detected. p-Cresol, indoleacetic acid, 4-methylthio-2-hydroxybutyric acid, and some unidentified alcohols were observed. The basic chloroform extraction contained cadaverine and putrescine. Leucine, norleucine, and isoleucine influenced the production of C5 and C6 acids and alcohols. L-Tyrosine underwent successive degradation to produce p-cresol and aromatic acids as final products. Tryptophan increased the production of indoleacetic, indolepropionic, and indolebutyric acids. Isocaproic acid was produced in relatively high concentrations regardless of medium substitution. The consistent production of iC6 under various substrate conditions indicates that the production of this compound might be consistent enough in vitro to form the basis of a rapid test for detection of C. difficile in stool specimens by frequency-pulsed electron capture gas-liquid chromatography.

Alcohols↗

PubMed1984

Studies of stools from pseudomembranous colitis, rotaviral, and other diarrheal syndromes by frequency-pulsed electron capture gas-liquid chromatography.

Thirty-five patients with various diarrheal syndromes and 22 controls were studied. All stool samples were carefully cultured for Clostridium difficile, using selective isolation media. Cytotoxin assays with proper antitoxin neutralization were done in MRC-5 cells. The stool samples were extracted four times, three times at pH 2 and once at pH 10, using CHCl3 or ether. Derivatizations of extracts were done with trichloroethanol, heptafluorobutyric anhydride, and heptafluorobutyric anhydride-ethanol, and all derivatives were analyzed by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). A dedicated computer was used to assist in both qualitative and quantitative data analysis. Isocaproic acid (iC6) was always found in stool from which C. difficile was isolated and was absent in C. difficile-negative specimens. p-Cresol was found frequently in both persons with pseudomembranous colitis and controls. Tryptamine was found in stool containing C. bifermentans. The FPEC-GLC profiles of persons with acute diarrhea were very different from those of normal persons. Diarrhea associated with adenovirus and rotavirus, Klebsiella spp., and Escherichia spp. showed different FPEC-GLC patterns. Stools from well persons consistently contained full-scale peaks of pyruvic, acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids. In rotavirus stools isobutyric, isovaleric, and valeric acids were reduced in quantity from those found in control stools, whereas propionic and butyric acids were increased.

Adult↗

PubMed1984

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.

Bacterial Toxins↗

PubMed1984

Pharmacist's role when dispensing pressurized aerosols for asthma.

Pharmacists should ensure that patients with asthma know how to use their pressurized aerosol medication, including bronchodilators and steroids. Inappropriate inhalation technique with these agents is common and may result in suboptimal response or therapeutic failure. Instruction by the pharmacist should include demonstration of the inhalation technique as well as the use of verbal and printed information. After demonstrating the use of the inhaler, the pharmacist should observe the patient to verify proper use. Instructions should be reinforced when prescriptions are refilled or if the patient is readmitted to the hospital. For patients who cannot learn proper inhalation technique, extension devices are now available.

Aerosols↗

PubMed1983

Studies of metabolic changes in cell cultures infected with four serotypes of dengue fever viruses by frequency-pulsed electron-capture gas-liquid chromatography.

Monkey kidney cell cultures were infected with four serotypes of dengue viruses, and the supernatant fluids of the cell cultures were extracted for amines, alcohols, carboxylic acids, and hydroxy acids. The derivatized extracts were then analyzed by frequency-pulsed electron-capture gas-liquid chromatography (FPEC-GLC). FPEC-GLC profiles of the hydroxy acids showed peaks that were different for different serotypes and the FPEC-GLC carboxylic acid profiles differed from the control medium. These differences were reproducible when the same lot for medium was used. There were differences in profiles between lots of control media due apparently to different fetal bovine sera used in the growth medium. Therefore, the same lot of medium was necessary to reproduce profiles. The data obtained from the study indicate that FPEC-GLC can be used to detect changes in cellular metabolism caused by viral infection, and that these metabolic changes might be useful in detection of genetic differences in viruses as reflected by detectable changes in the metabolism of the infected cell.

Alcohols↗

PubMed1983

Gas-liquid chromatography-frequency pulse-modulated electron-capture detection in the diagnosis of infectious diseases.

The extremely sensitive and selective gas-liquid chromatography-frequency pulsed-modulated electron-capture detection (GLC-FP-ECD) procedure has been applied to the diagnosis of bacterial, fungal, viral, rickettsial, and parasitic diseases by the examination of various body fluids, effusions and exudates, and excretion products. Carboxylic acid and alcohol, hydroxy acid, and amine product profiles of microbial or host-response origin, have been used to establish specific etiologies, these profiles are reproducible, and can be used to aid in the diagnosis of infections. In addition, we have used the GLC-FP-ECD procedure to analyze microbial metabolic products in vitro and to provide data for identification and classification. We also explored computer time-sharing for data analysis, profile library comparison, and eventual profile matching for diagnosis.

Alcohols↗

PubMed1983

The value of demonstration and role of the pharmacist in teaching the correct use of pressurized bronchodilators.

The use of an improper technique with metered-dose inhalers decreases the efficacy of the bronchodilators being administered. There is evidently a need for patients to watch a demonstration. Twenty-nine adult asthmatic patients from an allergy clinic were divided into three groups, each receiving a different form of instruction: an information sheet, personal instruction or a videotape presentation. Subsequently each patient was tested for correct use of the inhaler. There was no difference in mean scores for inhalation technique between the groups instructed in person and by videotape, but both were significantly better than the mean score of the group given only an information sheet. There was also no significant change in the scores at a follow-up test in the groups who saw the technique demonstrated. These results indicate the need for and value of the demonstration of proper technique with pressurized inhalers. A pharmacy-generated education system using videotape equipment or personal instruction by a pharmacist could readily solve the problem.

Adult↗

PubMed1981

Metabolic analysis of serologically defined Neisseria meningitidis isolates by frequency-pulsed electron capture gas-liquid chromatography.

Eight serogroups [A, B, C, D, X, Y, 29E [Z'], and W135] along with nongroupable and nontypable strains of Neisseria meningitidis were cultured in a defined liquid medium. The whole-culture spent medium was extracted, derivatized, and analyzed by frequency-pulsed electron capture gas-liquid chromatography. The frequency-pulsed electron capture gas-liquid chromatography profiles were then used to group the organisms on the basis of their metabolic profiles. First, two basic groups were formed which consisted of elevated spent-medium compounds and reduced spent-medium compounds. Then, these two basic groups were further subdivided on the basis of metabolites and cellular fatty acids detected in the spent medium to form a total of seven metabolic groups. The nongroupable strains (with the exception of two strains) fell within one of these metabolic groups. The elevated spent-medium compounds group contained all of the A, B, Y, and Z' strains, and the reduced spent-medium compounds group contained most of the C and all of the W135 and D strains. The potential usefulness of the metabolic group scheme is discussed.

Chromatography, Gas↗

PubMed1981

Rapid differentiation of rocky mountain spotted fever from chickenpox, measles, and enterovirus infections and bacterial meningitis by frequency-pulsed electron capture gas-liquid chromatographic analysis of sera.

Normal sera and sera from patients with Rocky Mountain spotted fever, chickenpox, enterovirus infections, measles, and Neisseria meningitidis infections were extracted with organic solvents under acidic and basic conditions and then derivatized with trichloroethanol or heptafluorobutyric anhydride-ethanol to form electron-capturing derivatives of organic acids, alcohols, and amines. The derivatives were analyzed by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). There were unique differences in the FPEC-GLC profiles of sera obtained from patients with these respective diseases. With Rocky Mountain spotted fever patients, typical profiles were detected as early as 1 day after onset of disease and before antibody could be detected in the serum. Rapid diagnosis of Rocky Mountain spotted fever by FPEC-GLC could permit early and effective therapy, thus preventing many deaths from this disease.

Adolescent↗

PubMed1981

Gas chromatography in the identification of microorganisms and diagnosis of infectious diseases.

Gas-liquid chromatography (GLC) continues to find increasing applications in the characterization of microorganisms and the diseases associated with them. GLC has been used to characterize microorganisms through qualitative and quantitative analyses of cellular structural components and soluble extracts and metabolic by-products. Chromatographic patterns, or fingerprints, can be used to differentiate between very closely related microorganisms, even strain differences, and provides a potentially powerful tool for future taxonomic studies and more precision in definitive microbial classification. However, the most valuable use of GLC is in the identification of disease through patterns obtained by direct analysis of body fluids. Chromatographic fingerprints of microbial metabolites and compounds associated with the host response to infection and even noninfectious disease can be used to develop relatively simple GLC diagnostic methods. These methods are specific, sensitive, and rapid. This review examines the use of GLC for identification of infectious diseases through the analysis of body fluids, spent culture media, and cellular materials and suggest other clinical areas where its diagnostic potential has yet to be developed.

Bacterial Infections↗

PubMed1980

Rapid differentiation of the major causative agents of bacterial meningitis by use of frequency-pulsed electron capture gas-liquid chromatograph: analysis of acids.

The major causative agents of bacterial meningitis, Haemophilus influenzae serogroup B, Neisseria meningitidis serogroups B and C, Klebsiella pneumoniae, Streptococcus pneumoniae, and two types of Escherichia coli, were cultured in a modified chemically defined Catlin medium and in a commercial version of the unmodified Catlin medium. The spent media were extracted under acidic conditions, and electron-capturing derivatives were prepared by derivatization with trichloroethanol or haptafluorobutyric anhydride. The derivatives were analyzed on a gas chromatograph equipped with a frequency-pulsed electron capture detector and a PEP-2 computer. The data obtained from the study show that these organisms can be easily distinguished from each other on the basis of metabolic products detected in either type of medium. Three different metabolic groups were detected within two serogroups of N. meningitidis. The methods are practical, and the new technique should offer clinical laboratories and hospitals a better method for rapid identification of this important group of pathogens.

Acids↗

PubMed1980

Rapid differentiation of the major causative agents of bacterial meningitis by use of frequency-pulsed electron capture gas-liquid chromatography: analysis of amines.

The major causative agents of bacterial meningitis (Haemophilus influenzae serogroup B, Neisseria meningitidis serogroups B and C, Klebsiella pneumoniae, Steptococcus pneumoniae, and two types of Escherichia coli) were cultured in a chemically defined medium, and selected strains were further studied in Todd-Hewitt medium. After acidic extraction of the spent media with chloroform, a basic extraction was made with chloroform to obtain amines. A third extraction was performed on re-acidified Todd-Hewitt medium with ethyl ether to obtain hydroxyacids. The extracts were derivatized with heptafluorobutyric anhydride-ethanol to form electron-capturing derivatives, and the derivatives were analyzed on a frequency-pulsed electron capture gas-liquid chromatograph (FPEC-GLC) equipped with a PEP-2 computer. The data obtained from the study showed that amines were produced by these organisms that formed characteristic patterns. Different serotypes of K. pneumoniae and the two serogroups of N. meningitidis produced different types of FPEC-GLC profiles within serotypes. E. coli produced several hydroxy acids on Todd-Hewitt medium that made it unique among the organisms studied. The methods used are practical and the techniques have potential for use in clinical laboratories and hospitals as a valuable aid for the rapid identification of the major causative agents of bacterial meningitis.

Amines↗

PubMed1980

Frequency-pulsed electron capture gas-liquid chromatography and the tryptophan color test for rapid diagnosis of tuberculous and other forms of lymphocytic meningitis.

A total of 260 samples of cerebrospinal fluid received from Egypt, the United States, Canada, and South America were examined by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC) for tuberculous and other forms of lymphocytic meningitis. Thirty-four of the specimens were culture positive for M. tuberculosis, and four cerebrospinal fluid specimens of herpes meningitis were established by immunological techniques. The compound, 3-(2'-ketohexyl)-indoline, was found in about 60% of the Egyptian tuberculous specimens and none of the culture-positive American specimens. the carboxylic and hydroxy acid FPEC-GLC profiles were used effectively in conjunction with other clinical data to make the diagnosis even in the absence of 3-(2'-ketohexyl)indoline. Herpes meningitis and mixed infections of Myeobacterium tuberculosis-herpes, M. tuberculosis-leptospira, and M. tuberculosis-Haemophilus influenzae produced profiles different from each other and from pure culture cases. The color test for tuberculous meningitis was evaluated, and free tryptophan was eliminated as the source of color reaction. Indications are that 3-(2'-ketohexyl)indoline, in most cases, is not responsible for the positive color reaction. Differences in the clinical and FPEC-GLC data obtained from samples from different geographical regions are discussed.

Cerebrospinal Fluid↗

PubMed1979

Electron capture gas-liquid chromatographic-mass spectral identification of acids produced by Neisseria meningitidis in a defined medium.

The acid metabolites and the cellular fatty acids of three strains of Neisseria meningitidis grown in a chemically defined liquid medium were determined with computerized frequency-pulsed electron capture gas-liquid chromatography. Five acids not previously reported were subsequently identified: isobutyric, octanoic, decenoic (C10:1), dodecenoic (C12:1), and tetradecenoic (C14:1). These acids were produced during active metabolism and were not detected as cellular constituents. The frequency-pulsed electron capture gas-liquid chromatography methods which we used provide a rapid, reliable, sensitive means of detecting both these and other metabolic and cellular acids in spent culture medium.

Chromatography, Gas↗

PubMed1978

Identification of some basic extractable compounds produced by Neisseria gonorrhoeae and Neisseria meningitidis in a defined medium.

Electron capture gas-liquid chromatography and mass spectrometry have been used to identify some of the basic extractable heptafluorobutyric anhydride reactive compounds found in a defined medium after 20 h of growth by Neisseria gonorrhoeae and N. meningitidis. Acetoin, 2,3-butanediol, pyrroline, and 1,3-diaminopropane were identified by both gas chromatography and mass spectrometry; 2-hydroxy-pyrrolidine and 3-aminomethyl-pyrrolidine were tentatively identified by mass spectrometry. A possible origin of the amines is through enzymatic oxidation of polyamines.

Acetoin↗

PubMed1978

Possible use of frequency-pulse-modulated electron capture gas-liquid chromatography to identify septic and aseptic causes of pleural effusions.

Frequency-pulse-modulated electron capture gas-liquid chromatography was used in conjunction with appropriate derivatization procedures to obtain chromatograms from extracts of pleural effusions. These chromatograms were used to rapidly classify the various types of pleural effusions. With this method we have been able to distinguish among a limited number of effusions caused by congestive heart failure, Mycobacterium tuberculosis, and some other types of bacterial empyemas and pleural effusions.

Chromatography, Gas↗

PubMed1978

Electron capture gas-liquid chromatographic study of metabolites produced by some arthritic transudate-associated organisms in vitro and in vivo in rabbit models.

Computerized, frequency-pulsed, modulated electron capture gas-liquid chromatography was used to study the acid metabolites produced in vitro in fetal calf serum and in vivo in an animal chamber model. Several strains of Diplostreptococcus agalactiae, Propionibacterium acnes, Staphylococcus aureus, and Streptococcus serogroups A, B, and G were studied. All of these organisms have been reported to be associated with arthritic transudates in humans. Metabolites were detected by this method from derivatized extracts of both spent fetal calf serum and chamber fluids. Since there was little host response to the organisms cultured in the chambers, it is highly probable that the products detected represent metabolites produced in an in vivo type of environment. The metabolic patterns were reproducible and exhibited many similarities in vitro and in vivo. Production of the acids detected was reproducible, and these acids were useful identification markers. The data support published reports (J. B. Brooks, C. C. Alley, and J. A. Liddle, Anal. Chem. 46: 1930-1934, 1974; J. B. Brooks, G. Choudhary, R. B. Craven, D. Edman, C. C. Alley, and J. A. Liddle, J. Clin. Microbiol. 5:625-628, 1977; J. B. Brooks, R. B. Craven, A. R. Melton, and C. C. Alley, in H. H. Johnson and W. B. Newson, ed., Second International Symposium on Rapid Methods and Automation on Microbiology, 1976; J. B. Brooks, R. B. Craven, D. Schlossberg, C. C. Alley, and F. M. Pitts, J. Clin. Microbiol. 8:203-208, 1978; J. B. Brooks, D. S. Kellogg, C. C. Alley, H. B. Short, and H. H. Handsfield, J. Infect. Dis. 129:660-668, 1974) that bacterial metabolites might be detectable in diseased body fluids. The growth characteristics of the organisms in the animal model and fetal calf serum are discussed, and a moderately priced computer for performing data manipulations is evaluated.

Acids↗

PubMed1977

Electron capture gas chromatography detection and mass spectrum identification of 3-(2'-ketohexyl)indoline in spinal fluids of patients with tuberculous meningitis.

A basic, extractable, indolic type of compound, which was derivatized with heptafluorobutyric anhydride and pyridine, was obtained from the cerebrospinal fluids of patients with acute tuberculous meningitis. The compound was detected by frequency-pulsed, modulated electron capture gas-liquid chromatography, and it was tentatively identified by mass spectrometry as 3-(2'-ketohexyl)indoline. The compound was found to be valuable for differentiating between tuberculous, cryptococcal, and aseptic meningitides.

Chemical Phenomena↗