Amino acids profiles of children who stutter compared to their fluent sibling

Development and evaluation of a novel fluorescent chiral derivatization reagent DBD-S-M-Pro: first observation of four chiral amino acids in human hair

“…In the biomedical arena, hair has been acknowledged as a noninvasive biological sample over the past few decades, and hair analysis for potential disease diagnosis has been frequently reported. [24][25][26][27][28][29] Hair analysis has attracted widespread interest and has led to the discovery of endogenous amino acids in human hair. 30,31 However, few of the existing methods can identify and measure D-amino acids in human hair.…”

Evaluating the discriminating power of amino acid ratios on distinguishing dark colored hair samples

“…Furthermore, specific GVP sequences need to be intact for reproducibility and the analysts need to be able to identify the GVPs in the protein sequence in order to differentiate the samples. Therefore, the use of an approach where proteomic information is still gathered but does not require proteins and/or peptides to remain intact to compare hair samples was investigated, which involved using the amino acid composition itself [12][13][14][15]. We hypothesize that amino acid ratios derived from hair protein analysis could provide enough information to differentiate hair samples that originated from different people, allowing exclusionary conclusions to be made based on quantifiable data.…”

“…Amino acid-based approaches have proved to be useful for differentiation purposes in terms of class characteristics. Rashaid et al demonstrated that amino acid quantities were useful for differentiating Jordanian subjects of varying sex, age group, geographic region of origin, and health conditions [12][13][14]. In one study, they showed that tyrosine and cysteine were most differentiating for their specific geographical location, alanine and glycine for age, and threonine and phenylalanine for sex.…”

“…In another similar study done by the same researchers, they found that isoleucine, glutamic acid, and glycine were most discriminating for diabetes mellitus [14]. In addition, an investigation into the amino acids in hair of people with a stutter, it was discovered that these individuals had lower concentrations of threonine, tyrosine, and isoleucine in their hair [12]. Finally, a similar study done using LC–MS found that children with autism had higher levels of glutamic acid and lower amounts of methionine, alanine, and asparagine in their hair [18].…”