Urinary carboxylic acids (UCAs) in subjects with autism spectrum disorder and their association with bacterial overgrowth

Abstract In this study, the levels of concentration of carboxylic acids (benzoic acid, p-hydroxybenzoic acid, p-hydroxyphenylacetic acid, and hippuric acid) in the urine of autistic children were investigated and compared. The increased excretion of carboxylic acids is related to excessive bacterial activity in the gut, called bacterial overgrowth, which has been related to autism spectrum disorder (ASD) as an impairment in the gut-brain axis. The investigation was based on the analysis of urine samples obtained from 120 ASD children. To identify and quantify urinary carboxylic acids (UCAs), we applied gas chromatography coupled with mass spectrometry (GC-MS). Additionally, we checked the influence of probiotic supplementation, gender, body mass index (BMI) value and age of children on the level of different selected compounds. Most of the obtained results were found within reference ranges. In some cases, the levels of benzoic acid, p-hydroxybenzoic acid, and p-hydroxyphenylacetic acid were particularly elevated. Statistically significant differences were observed in supplementation with probiotics and the level of p-hydroxyphenylacetic acid (p=0.036). The obtained results may indicate disturbances in the intestinal flora in some autistic patients and suggest that supplements may have an influence on the levels of carboxylic acids in urine. Due to the small population of children taking the supplement, further study are needed

Isoprostanes as potential cerebral vasospasm biomarkers

Despite enormous progress in medicine, symptomatic cerebral vasospasm (CVS), remains an unexplained clinical problem, which leaves both physicians and patients helpless and relying on chance, due to the lack of specific marker indicative of imminent danger as well as the lack of specific treatment. In our opinion CVS occurrence depends on dynamic disbalance between free radicals' formation (oxidative stress) and antioxidant activity. Isoprostanes are products of free-radical peroxidation of polyunsaturated fatty acids, and seem to mark a promising path for the research aiming to unravel its possible mechanism. Not only are they the biomarkers of oxidative stress in vivo and in vitro, but also have manifold biological effects (including vasoactive, inflammatory and mitogenic) via activation of the thromboxane A2 receptor (TBXA2R), both in physiological and pathophysiological processes. This review addresses the importance of isoprostanes in CVS in quest of appropriate biomarkers

Effect of Supplementation on Levels of Homovanillic and Vanillylmandelic Acids in Children with Autism Spectrum Disorders

Autism Spectrum Disorders (ASD) are characterized by numerous comorbidities, including various metabolic and nutritional abnormalities. In many children with ASD, problems with proper nutrition can often lead to inadequate nutrient intake and some disturbances in metabolic profiles, which subsequently correlate with impaired neurobehavioural function. The purpose of this study was to investigate and compare the relationship between supplementation, levels of homovanillic acid (HVA) and vanillylmandelic acid (VMA) and the behaviour of children with ASD using quantitative urinary acid determination and questionnaires provided by parents/caregivers. The study was carried out on 129 children between 3 and 18 years of age. HVA and VMA were extracted and derivatized from urinary samples and simultaneously analyzed by gas chromatography-mass spectrometry (GC-MS). In addition, parents/caregivers of children with ASD were asked to complete questionnaires containing information about their diet and intake/non-intake of supplements. The application of the Mann–Whitney U test showed a statistically significant difference between the level of HVA and vitamin B supplementation (p = 1.64 × 10−2) and also omega-6 fatty acids supplementation and the levels of HVA (p = 1.50 × 10−3) and VMA (p = 2.50 × 10−3). In some children, a reduction in the severity of autistic symptoms (better response to own name or better reaction to change) was also observed. These results suggest that supplementation affects the levels of HVA and VMA and might also affect the children’s behaviour. Further research on these metabolites and the effects of supplementation on their levels, as well as the effects on the behaviour and physical symptoms among children with ASD is needed

Homocysteine level in urine of autistic and healthy children

Homocysteine is an amino acid which plays several important roles in human physiology and is an important biomarker for possible deficiencies of various vitamins (vitamin B6 and B12, folic acid). In this work GC-MS method was used to determine the levels of homocysteine in the urine of autistic and healthy children. The levels of homocysteine in urine samples from 34 autistic and 21 healthy children were 2.36 ± 1.24 and 0.76 ± 0.31 (mmol∙mol-1 creatinine), respectively. The higher level of homocysteine in autistic children may indicate deficiencies of folic acid and vitamins B6 and B12 in nutrition of these children. The results of this work were taken into consideration in the nutrition of autistic children treated in the Navicula Centre of Diagnosis and Therapy of Autism in Łódź (Poland)

Thermal and thermo-catalytic degradation of polyolefins as a simple and efficient method of landfill clearing

Thermal degradation of the low density polyethylene (LDPE), polypropylene (PP) and the municipal waste plastics was investigated. The thermo-catalytic degradation of LDPE and PP was studied in the presence of the following catalysts: four different types of montmorillonite: K5, K10, K20, K30 and – for comparison – zeolites (natural – clinoptilolite, Y Na+ and YH+). Thermal analyses TG-DTA-MS of polymers and polymercatalyst mixtures were carried out in an argon flow atmosphere in isothermal and dynamic conditions. The following order was found: in lowering the reaction temperature for LDPE degradation YH+> mK5 > mK20 = mK30 >mK10 > NZ > YNa+; for PP degradation: mK20 > mK5 = mK30 >mK10 > YH+> NZ >YNa+. The activity tests were carried out in a stainless steel batch reactor under atmospheric pressure in a wide temperature range of up to 410°C, and using the atmosphere of argon flow. The liquid products were analysed by the GC-MS method. The hydrocarbons in the liquid products from thermal degradation of polymers were broadly distributed in the carbon fractions of C8 to C26 – for LDPE and C6 to C31for PP

A focus on homocysteine in autism

Homocysteine is an amino acid, which plays several important roles in human physiology. A wide range of disorders, including neuropsychiatric disorders and autism, are associated with increased homocysteine levels in biological fluids. Various B vitamins: B6 (pyridoxine), B12 (cobalamin), and B9 (folic acid) are required as co-factors by the enzymes involved in homocysteine metabolism. Therefore, monitoring of homocysteine levels in body fluids of autistic children can provide information on genetic and physiological diseases, improper lifestyle (including dietary habits), as well as a variety of pathological conditions. This review presents information on homocysteine metabolism, determination of homocysteine in biological fluids, and shows abnormalities in the levels of homocysteine in the body fluids of autistic children

Thermal and thermo-catalytic degradation of polyolefins as a simple and efficient method of landfill clearing

Thermal degradation of the low density polyethylene (LDPE), polypropylene (PP) and the municipal waste plastics was investigated. The thermo-catalytic degradation of LDPE and PP was studied in the presence of the following catalysts: four different types of montmorillonite: K5, K10, K20, K30 and – for comparison – zeolites (natural – clinoptilolite, Y Na+ and YH+). Thermal analyses TG-DTA-MS of polymers and polymercatalyst mixtures were carried out in an argon flow atmosphere in isothermal and dynamic conditions. The following order was found: in lowering the reaction temperature for LDPE degradation YH+> mK5 > mK20 = mK30 >mK10 > NZ > YNa+; for PP degradation: mK20 > mK5 = mK30 >mK10 > YH+> NZ >YNa+. The activity tests were carried out in a stainless steel batch reactor under atmospheric pressure in a wide temperature range of up to 410°C, and using the atmosphere of argon flow. The liquid products were analysed by the GC-MS method. The hydrocarbons in the liquid products from thermal degradation of polymers were broadly distributed in the carbon fractions of C8 to C26 – for LDPE and C6 to C31for PP