Detection of Leachable Components from Conventional and Dental Bulk-Fill Resin Composites (High and Low Viscosity) Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Method.

The aim of this study was to investigate leachable components (monomers) in high and low viscosity dental bulk-fill resin composites and conventional resin composite materials after polymerization. Six bulk-fill and six conventional dental resin composite materials were used in this study. The samples of each material (three sets of triplicates) were cured for 20 s with irradiance of 1200 mW/cm2 with a LED curing unit and immersed in a 75% ethanol solution at 37 °C. The eluates from each triplicate set were analyzed after 24 h, 7 days or 28 days using liquid chromatography coupled with triple quadrupole tandem mass spectrometry (LC-MS/MS). Detectable amounts of 2-Hydroxyethyl methacrylate (HEMA) were found in both Gradia materials and the amount observed across different time points was statistically different (p ˂ 0.05), with the amount in solution increasing for Gradia and decreasing for Gradia Direct flo. Bisphenol A diglycidildimethacrylate (BIS GMA) was found in Filtek and Tetric materials. Triethylene glycol dimethacrylate (TEGDMA) was detected in all materials. On the other hand, there were no statistically significant differences in the amounts of TEGDMA detected across different time points in either of the tested materials. Monomers HEMA, TEGDMA, 4-dimethylaminobenzoic acid ethyl ester (DMA BEE) and BIS GMA in bulk-fill and conventional composites (high and low viscosity) can be eluted after polymerization. The good selection of composite material and proper handling, the following of the manufacturer's instructions for polymerization and the use of finishing and polishing procedures may reduce the elution of the unpolymerized monomers> responsible for the possible allergic and genotoxic potential of dental resin composites.

The correlation of the lifestyle and medical conditions with the vaginal infections and production of 2-phenylethanol.

OBJECTIVE: The objective of this study was determination of causative factors of the genital infections and their correlation with various predictor variables. Secondary objectives included: (1) determination of the presence and the type of low molecular weight metabolites in the samples of vaginal secretion formed in vivo, (2) determination of the concentration of 2-phenylethanol formed in vitro for each Candida species, (3) determination of the relationship between fungal/bacterial/viral infections with the metabolites formed in vivo using multivariate analysis. METHODS: One hundred and ninety-seven women in the age range from 18 to 65 years were included in the study. After the completion of questionnaire, all the patients were subjected to Pap test, cervical swabs for the presence of aerobic bacteria, yeasts, Ureaplasma urealyticum, Chlamydia trachomatis, Mycoplasma, and hrHPV DNA. The presence and the concentration of low-molecular weight metabolites in vitro and in vivo were determined by gas chromatography-mass spectrometry (GC-MS) method. Multivariate analysis methods were used for statistical evaluation. RESULTS: The most important risk factors of fungal/bacterial/viral infections were determined. The presence of 2-phenylethanol in vivo was confirmed in 14 of 74 tested samples and connected with the Candida species. The presence of symptoms, hrHPV DNA and Ureaplasma urealyticum are the predictor variables with the highest influence on the formation of the metabolite in vivo. The results in vitro confirmed that various Candida species produced 2-phenylethanol with the concentrations ranging from 0.6 to 4.64 µg/mL. CONCLUSION: The medical exposure to irradiation, marital status, and number of partners as well as stress factors (miscarriages, chronic, viral, or tumor illnesses) had the highest influence on the development of the bacterial/fungal/viral infections. The formation of 2-phenylethanol, both in vivo and in vitro, was confirmed and connected with Candida species. Besides, according to statistical tests, it seems that presence of symptoms, hrHPV DNA, and Ureaplasma urealyticum had also significant role on the formation of 2-phenylethanol in vivo.

Identification and quantification of lignans in wheat bran by gas chromatography-electron capture detection.

Whole grain cereals are an important source of bioavailable lignans, the group of compounds with potential anti-cancerogenic, antioxidant, anti-proliferative, pro-apoptotic, and antiangiogenic properties. The aim of this work was to develop a sensitive method for determination of wheat bran lignans. The analysis of lignans secoisolariciresinol, hydroxymatairesinol, lariciresinol, matairesinol, pinoresinol, syringaresinol is based on derivatization with pentafluoropropionic anhydride (PFPA) and gas chromatography-electron capture detection (GC-ECD), using styrene glycol as internal standard. To our knowledge, this is the first time that EC detection has been used for lignan analysis. The results show that the technique is reproducible and sensitive enough for detecting lignans in wheat at parts-per-billion (ppb) levels, except for hydroxymatairesinol. The method developed showed good recovery (85-105%) and precision (4-20%) for five types of lignans and thus represents a simpler and more affordable alternative to state-of-the-art wheat lignan liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis.