The Biocatalytic Potential of Aromatic Ammonia-Lyase from Loktanella atrilutea.

Characterization of the aromatic ammonia-lyase from Loktanella atrilutea (LaAAL) revealed reduced activity towards canonical AAL substrates: l-Phe, l-Tyr, and l-His, contrasted by its pronounced efficiency towards 3,4-dimethoxy-l-phenylalanine. Assessing the optimal conditions, LaAAL exhibited maximal activity at pH 9.5 in the ammonia elimination reaction route, distinct from the typical pH ranges of most PALs and TALs. Within the exploration of the ammonia source for the opposite, synthetically valuable ammonia addition reaction, the stability of LaAAL exhibited a positive correlation with the ammonia concentration, with the highest stability in 4 M ammonium carbamate of unadjusted pH of ~9.5. While the enzyme activity increased with rising temperatures yet, the highest operational stability and highest stationary conversions of LaAAL were observed at 30 °C. The substrate scope analysis highlighted the catalytic adaptability of LaAAL in the hydroamination of diverse cinnamic acids, especially of meta-substituted and di-/multi-substituted analogues, with structural modelling exposing steric clashes between the substrates' ortho-substituents and catalytic site residues. LaAAL showed a predilection for ammonia elimination, while classifying as a tyrosine ammonia-lyase (TAL) among the natural AAL classes. However, its distinctive attributes, such as genomic context, unique substrate specificity and catalytic fingerprint, suggest a potential natural role beyond those of known AAL classes.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project.

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

Rapid identification of sibutramine in dietary supplements using a stepwise approach.

Adulteration of botanical food supplements with undeclared synthetic drugs is a common problem. One of the most affected product groups are the slimming agents. There are no analytical protocols for the detection of synthetic adulterants from these products. The present study aimed at the development of a multistep analytical method for the quick and reliable determination of sibutramine, one of the most common adulterants among botanical food supplements. The extract of a sibutramine-containing slimming formula was analysed by colour tests, TLC, HPLC-DAD, MS and NMR. The multistep method proposed by the authors allows the quick identification of sibutramine in counterfeit samples in laboratories with different instrumentation.

Does the menstrual cycle influence the motor and phosphene thresholds in migraine?

BACKGROUND AND PURPOSE: The excitability of the visual and motor cortical areas is altered in migraineurs. Controversial results of previous studies on cortical excitability may depend on the hormonal status of female subjects. The present study aimed to determine whether the different phases of the menstrual cycle influence the phosphene thresholds (PT) and resting motor thresholds (RMT) in migraineurs. METHODS: Thirty-two migraine patients participated in this study. Three to six PT and RMT measurements were done in headache-free intervals during the follicular, middle and luteal phases of the female cycle, or in active dosage and withdrawal phases in patients who were taking low dosage oral contraceptives. RESULTS: Generally, PTs showed higher individual variabilities than RMTs. Additionally, we have observed that the RMTs and PTs were significantly independent from hormonal changes. However, patients who were taking a low dosage of oral contraceptives had lower PTs compared with patients who were not taking oral contraceptives. RMTs show the opposite tendency. CONCLUSION: The results imply that PTs and RMTs can be reliably measured independently from the menstrual hormone status in female migraineurs.