Determination of urinary D-/L-arabinitol ratios as a biomarker for invasive candidiasis in children with cardiac diseases

A novel molecular imprinting polymer for the selective adsorption of D-arabinitol from spiked urine

In this research, molecular imprinting polymers (MIPs) for D-arabinitol were synthesized using a bulk polymerization method through a noncovalent approach. The MIPs were prepared by using D-arabinitol as a template, acrylamide as a functional monomer, ethylene glycol dimethacrylateas cross-linker, benzoyl peroxide as an initiator and dimethyl sulfoxideas a porogen. MIPS was synthesized in several formulas with a different molar ratio of template to functional monomers and cross-linker. Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used to characterize the MIPs produced. A batch rebinding assay was used to test the binding efficiency of each formula. Batch rebinding test results revealed that MIPsF3 with a molar ratio of the template: monomer and crosslinker ratio respectively (1: 4: 25) had the highest binding capacity at 1.56 mgg ^-1 . The results of isotherm adsorption showed that the MIPs produced followed the Freundlich equation with an R-value of 0.97. The MIPs produced was also selective toward its isomeric compounds (i.e. L-arabinitol, adonitol, xylitol, and glucose). The extraction efficiency of the MIPs against D-arabinitol was 88.98%.

The Promising Role of Probiotics in Managing the Altered Gut in Autism Spectrum Disorders

Gastrointestinal symptoms (GIS) have been reported repeatedly in people with autism spectrum disorder (ASD) and studies have reported interesting correlations between severity of behavioral and gastrointestinal symptoms. Growing evidence indicates that the gut microbiota in ASD is altered with various shifts described at different taxonomic levels, pointing to the importance of considering the gut-brain axis in treatment of these disorders. Probiotics are live beneficial bacteria that are ingested as food or customized pills. These beneficial bacteria, when added in sufficient amounts, can correct the dysbiosis. Because probiotics have shown success in treating irritable bowel syndrome (IBS), it is plausible to investigate whether they can induce alleviation of behavioral symptoms as well. Probiotics show, in some clinical studies, their potential benefits (1) in improving gastrointestinal dysfunction, (2) in correcting dysbiosis, (3) in consequently reducing the severity of ASD symptoms. This review compiles data from selected studies that investigate these benefits and the mechanisms that mediate these effects, which include the production of metabolites, hormones, and neurotransmitters and the regulation of pro-inflammatory and regulatory cytokines. Future research based on more randomized, controlled studies with a larger population size and standardized use of strains, concentration of probiotics, duration of treatments, and methods of DNA extraction is still needed in this area, which may lead to more robust results.

Role of Probiotics in Managing Gastrointestinal Dysfunction in Children with Autism Spectrum Disorder: An Update for Practitioners

Children with autism spectrum disorder (ASD) are 4 times as likely to experience gastrointestinal symptoms as children without ASD. The gut microbiota has increasingly been the subject of investigation as a contributing factor to these symptoms in this population because there is evidence to suggest that alterations in the intestinal microflora are correlated with gastrointestinal and ASD symptom severity. Probiotic therapy has been proposed as a treatment for augmented gastrointestinal symptom severity in children with ASD. This narrative review systematically searched the literature to provide an update for practitioners on the state of the evidence surrounding probiotic therapy in children with ASD as a treatment option for reducing gastrointestinal symptoms. A total of 186 articles were screened and 5 articles met the inclusion criteria. A collective sample of 117 children with ASD is represented and outcomes addressed include improvement in gastrointestinal symptoms as well as influence of probiotic supplementation on the gut microbiota and ASD symptoms and behavior. There is promising evidence to suggest that probiotic therapy may improve gastrointestinal dysfunction, beneficially alter fecal microbiota, and reduce the severity of ASD symptoms in children with ASD. Future research is still warranted in this area because there are methodologic flaws in the available literature and optimal species, strains, dosages, and duration of treatment have not been identified.

Biochemical characterization of the CDP-D-arabinitol biosynthetic pathway in Streptococcus pneumoniae 17F

Streptococcus pneumoniae is a major human pathogen associated with many diseases worldwide. Capsular polysaccharides (CPSs) are the major virulence factor. The biosynthetic pathway of D-arabinitol, which is present in the CPSs of several S. pneumoniae serotypes, has never been identified. In this study, the genes abpA (previously known as abp1) and abpB (previously known as abp2), which have previously been reported to be responsible for nucleoside diphosphate (NDP)-D-arabinitol (the nucleotide-activated form of D-arabinitol) synthesis, were cloned. The enzyme products were overexpressed, purified, and analyzed for their respective activities. Novel products produced by AbpA- and AbpB-catalyzing reactions were detected by capillary electrophoresis, and the structures of the products were elucidated using electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. As a result, abpA was identified to be a D-xylulose-5-phosphate cytidylyltransferase-encoding gene, responsible for the transfer of CTP to D-xylulose-5-phosphate (D-Xlu-5-P) to form CDP-D-xylulose, and abpB was characterized to be a CDP-D-xylulose reductase-encoding gene, responsible for the conversion of CDP-D-xylulose to CDP-D-arabinitol as the final product. The kinetic parameters of AbpA for the substrates D-Xlu-5-P and CTP and those of AbpB for the substrate CDP-D-xylulose and the cofactors NADH or NADPH were measured, and the effects of temperature, pH, and cations on the two enzymes were analyzed. This study confirmed the involvement of the genes abpA and abpB and their products in the biosynthetic pathway of CDP-D-arabinitol.