Toothpastes with Enzymes Support Gum Health and Reduce Plaque Formation.

Enzymes in toothpastes can support host immune responses, and thus maintain oral health. This study aimed to investigate gingival health and the plaque-reducing effects of enzyme-containing toothpastes. A laboratory study tested the antimicrobial potential of different enzyme-containing toothpaste formulations. Two promising formulations (enzyme-containing toothpastes with glucose oxidase and D-glucose with (C+) and without Citrox (C-) Citrox) were investigated in a clinical crossover trial (two slurries: sodium lauryl sulfate-containing (SLS), a toothpaste without SLS (reference), and water). Subjects (n = 20) abstained from toothbrushing for four days and rinsed with a toothpaste slurry. Bleeding on probing (BOP) and plaque indices (PI) were measured. A mixed linear model was used to statistically compare the slurries with respect to BOP and PI change. The in vitro bacterial growth-inhibiting evaluation showed the best results for SLS, followed by C+ and C-. The change in BOP and PI exhibited statistically significant differences to water rinsing (BOP; PI changes in % points (difference of the baseline and post-rinse values: water = 8.8%; 90.0%; C+ = -1.4%; 80.4%; SLS = 1.5%; 72.1%; reference = 0.8%; 77.5%; C- = -1.8%; 75.1%). All slurries exhibited anti-gingivitis and anti-plaque effects, resulting in a prophylactic benefit for limited-access regions during brushing.

An enzymatic method to determine γ-hydroxybutyric acid in serum and urine.

BACKGROUND: Gamma-hydroxybutyric acid (GHB) has become one of the most dangerous illicit drugs of abuse today. It is used as a recreational and date rape drug because of its depressant effect on the central nervous system, which may cause euphoria, amnesia, respiratory arrest, and coma. There is an urgent need for a simple, easy-to-use assay for GHB determination in urine and blood. In this article, a rapid enzymatic assay adapted to clinical chemistry analyzers for the detection of GHB is presented. METHODS: The described GHB enzymatic assay is based on a recombinant GHB dehydrogenase. The full validation of the assay was performed on a Konelab 30 analyzer (Thermo Fisher Scientific). RESULTS: The analytical sensitivity was <1.5 mg/L, whereas the functional sensitivity was 4.5 mg/L in serum and 2.8 mg/L in urine. The total imprecision coefficient of variation (CV) was <9.8% in serum and <7.9% in urine. The within-run imprecision showed a CV of <3.8% in serum and <4.6% in urine. The assay was linear within the range 5-250 mg/L. Mean recoveries were 109% in serum and 105% in urine. No cross-reactivity was observed for tested GHB analogues and precursors. Comparison of GHB-positive samples showed an excellent correlation with ion chromatography, gas chromatography-mass spectrometry, and liquid chromatography associated to tandem mass spectrometry. Except for ethanol, no substantial interference from serum constituents and some drugs was observed. CONCLUSIONS: This automated GHB assay is fully quantitative and allows the accurate measurement of GHB in serum and urine. It can be used as a rapid screening assay for the determination of GHB in intoxicated or overdosed patients.

Disparate oxygen responsiveness of two regulatory cascades that control expression of symbiotic genes in Bradyrhizobium japonicum.

Two oxygen-responsive regulatory systems controlling numerous symbiotic genes in Bradyrhizobium japonicum were assayed in free-living cultures for their capacity to activate target genes under different oxygen conditions. NifA- and FixLJ-controlled target genes showed disparate relative expression patterns. Induction of NifA-dependent genes was observed only at oxygen concentrations below 2% in the gas phase, whereas that of FixLJ-controlled targets progressively increased when the oxygen concentration was lowered from 21 to 5, 2, or 0.5%. We propose that this reflects a response to a gradient of increasing oxygen deprivation as bacteria invade their host during root nodule development.