Arabinitol enantiomers in cerebrospinal fluid

The level of arabinitol in autistic children after probiotic therapy

OBJECTIVE

The level of D-arabinitol (DA) and the ratio of D-/L-arabinitol (DA/LA) in the urine of children with autism were investigated. The changes in DA/LA after probiotic treatment in urine samples of children with autism were studied.

METHODS

DA and LA and the DA/LA ratio were identified by capillary gas chromatography/mass spectrometry in urine before and after the probiotic therapy.

RESULTS

The level of DA is significantly higher (P < 0.05) in the urine of autistic children before (A) and after probiotic supplementation (A1) (160.04 ± 22.88 μmol/mmol creatinine and 89.53 ± 37.41 μmol/mmol creatinine, respectively). Nonetheless, the probiotic supplementation let to a significant decrease in DA and DA/LA and to a significant improvement in ability of concentration and carrying out orders.

CONCLUSION

The use of probiotics seems to be helpful in reducing the level of DA and the ratio of DA/LA in the urine of children with autism.

D-arabinitol--a marker for invasive candidiasis

The five-carbon sugar alcohol D-arabinitol (DA) is a metabolite of most pathogenic Candida species, in vitro as well as in vivo, and can be determined by gas chromatography or enzymatic analysis. Endogenous DA and L-arabinitol (LA) are present in human body fluids, and serum DA and LA increase in renal dysfunction. In prospective clinical studies, elevated DA/LA or DA/creatine ratios in serum or urine have been found in immunocompromised, usually neutropenic, patients with invasive candidiasis. In addition, positive DA results have been obtained several days to weeks before positive blood cultures, and the normalization of DA levels has been correlated with therapeutic response in both humans and animals. However, to date, only a few prospective studies have been conducted in which adequate analytical methods were used. Thus, further investigation of various patient groups is needed to establish the applicability of the 'arabinitol method' in the diagnostic battery for invasive Candida infections.

Leukoencephalopathy associated with a disturbance in the metabolism of polyols

In vivo proton magnetic resonance spectroscopy of the brain demonstrated highly elevated levels of arabitol and ribitol in a 14-year-old boy with a white matter disorder and neuropathy of unknown origin. These polyols also were shown to be elevated in body fluids, suggesting an inborn error in polyol metabolism. The strong plasma/ cerebrospinal fluid/brain gradient, with concentrations increasing in that order, suggests a primary neurometabolic disorder. Thus far, a basic enzyme defect has not been identified.

Gas chromatographic determination of D-arabinitol/L-arabinitol ratios in urine: a potential method for diagnosis of disseminated candidiasis

A gas chromatographic procedure was developed to determine the relative amounts of D- and L-arabinitol in urine. Samples were filtered, diluted, purified through extractions, evaporated, and treated with trifluoroacetic anhydride; the arabinitol derivatives thus obtained were separated on a chiral stationary phase and registered by using an electron-capture detector. Urine samples from a patient with disseminated candidiasis had higher D-arabinitol/L-arabinitol ratios (referred to as D/L-arabinitol ratios)--up to 19.0--than samples from 96 study individuals with no signs of deep Candida infections (range, 1.1 to 4.5). D/L-Arabinitol ratios in urine samples from hospitalized patients without Candida infections were slightly higher than those in samples from healthy individuals; ratios in urine from children were slightly higher than those in adult urine samples. The D/L-arabinitol ratios in several urine samples culture positive for Candida albicans, but from patients without symptoms of disseminated candidiasis, did not differ from those in the urine of healthy individuals. The described gas chromatographic method is straightforward and can be implemented clinically to determine urine D/L-arabinitol ratios as a means of diagnosing disseminated candidiasis.

Determination of microbial chemical markers by gas chromatography-mass spectrometry--potential for diagnosis and studies on metabolism in situ. Review article

Different strategies for the application of gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) in medical microbiology research are discussed. GC can be used to determine specific microbial monomeric constituents and metabolites, so-called chemical markers, in cultures of microorganisms; in particular, analysis of cellular fatty acids has proven useful for species characterization and identification. GC-MS can be applied to study chemical markers directly in complex environmental samples, as exemplified by the analysis of airborne organic material as regards muramic acid (marker of peptidoglycan), 3-hydroxy acids (endotoxins), and ergosterol (fungal biomass). This methodological approach represents an alternative to various biological assays for characterization of airborne microbial structures, and forms a firm basis for correlating inhalation of such structures and development of symptoms. Direct GC-MS analysis of clinical samples provides possibilities for diagnosis (here exemplified by chiral separation of urine D- and L-arabinitol in disseminated candidiasis) and insight into microbial metabolism in the infected host (exemplified by observed indications of mycobacterial build-up of mycolic acids in vivo), with implications for drug development. Continued developments in MS technology will allow rapid advances to be made in GC-MS research in microbiology.