Dietary risk evaluation of acrylamide intake with bread in Poland, determined by two comparable cleanup procedures.

Acrylamide is regarded as a food chemical contaminant. The aims of this work included: (i) to develop sample cleanup procedures applicable for determination of AA in soft bread samples; (ii) to determine AA levels in soft bread available in retail trade in Poland and to compare them with currently standing benchmark levels; (iii) to determine dietary risk related to AA in soft bread. The procedure based on ion-exchange solid phase extraction was more suitable to obtain LOQs corresponding to AA concentrations in soft bread samples. AA levels found in bread samples were in 3.6-163 µg kg-1 range. AA levels varied greatly from sample to sample, which suggests that both food composition and manufacturing processes play a crucial role in AA generation. When considering reference point for neoplastic effects, Margin of Exposure calculated for AA taken with soft bread ranged between 543 and 3,035.

Oral and topical pharmacokinetic studies of a novel TRPV1 antagonist, PAC-14028 in rats and minipigs using liquid chromatography/tandem mass spectrometric method.

PAC-14028 ((E)-N-((R)-1-(3,5-difluoro-4-methanesulfonylamino-phenyl)-ethyl)-3-(2-propyl-6-trifluoromethyl-pyridine-3-yl)-acrylamide) is a novel and potent transient receptor potential vanilloid type I (TRPV1) antagonist. We developed and validated a rapid, sensitive and selective liquid chromatography/tandem mass spectrometric method for determination of PAC-14028 in rat and minipig plasma. After protein precipitation PAC-14028 and internal standard (methylated analog, PAC-14026) were separated on a Symmetry C(18) column (4.6 mm × 75 mm, 3.5 µm) with an isocratic mobile phase, acetonitrile: water (8:2, v/v) containing 0.2% formic acid and monitored by electrospray positive ionization with multiple reaction monitoring mode (PAC-14028, 492→156; IS, 506→156, m/z). The calibration curve was linear over the range of 1.0-500 ng/ml (r(2)>0.999) and lower limit of quantitation (LLOQ) was 1 ng/ml. The precision and accuracy were within ± 15% and the stability was acceptable during bench-top, auto-sampler, 3 freeze-thaw cycles and 4-week storage in a freezer at -80°C. This method was successfully applied to the intravenous, oral and topical pharmacokinetic studies of PAC-14028 in rats and minipigs, which showed comparable pharmacokinetic parameters (T1/2, 2.1h and 3.8h; F%, 52.7% and 64.2% for rats and minipigs, respectively). Percutaneous absorption of PAC-14028 was negligible after topical application (F% 0.2-1.7%).

LC-MS of palytoxin and its analogues: State of the art and future perspectives.

The state of the art of LC-MS of palytoxin and its analogues is reported in the present review. MS data for palytoxin, 42-hydroxy-palytoxin, ostreocin-D, mascarenotoxins, and ovatoxins, obtained using different ionization techniques, namely fast-atom bombardment (FAB), matrix assisted laser desorption ionization (MALDI), and electrospray ionization (ESI), are summarized together with the LC-MS methods used for their detection. Application of the developed LC-MS methods to both plankton and seafood analysis is also reported, paying attention to the extraction procedures used and to limits of detection (LOD) and quantitation (LOQ) achieved. In a research setting, LC-MS has shown a good potential in determination of palytoxin and its analogues from various sources, but, in a regulatory setting, routine LC-MS analysis of palytoxins is still at a preliminary stage. The LOQ currently achieved in seafood analysis appears insufficient to detect palytoxins in shellfish extract at levels close to the tolerance limit for palytoxins (30 µg/kg) proposed by the European Food Safety Authority (EFSA, 2009). In addition, lacking of certified reference standard of palytoxins as well as of validation studies for the proposed LC-MS methods represent important issues that should be faced for future perspectives of LC-MS technique.

Biocompatibility evaluation of laser-induced AAm and HEMA grafted EPR. Part 1: In-vitro study.

Samples based on ethylene-propylene rubber (EPR) have been surface grafted with acrylamide (AAm) and 2-hydroxyethyl methacrylate (HEMA) using CO2-pulsed laser as a stimulation source. Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA) and attenuated total reflectance infrared (ATR-IR) spectra were performed on the modified samples. These techniques revealed the formation of grafted poly(AAm) and poly(HEMA) on the surface of EPR. The surface grafted poly(AAm) and poly(HEMA) were found to have a fractal type of morphology. EDXA showed insignificant grafted AAm and HEMA in regions where fractals were absent. Fractal patterned surfaces provide hydrophilic and hydrophobic sites, making EPR suitable as a biomaterial. In-vitro adhesion and spreading of alveolar macrophages (AMs) cultured on the surface of modified samples have been evaluated by hemocytometry and SEM, respectively, and compared with unmodified controls. Relationships between AM adhesion and their spreading, with surface morphology, graft level and water compatibility are also discussed. Generally, more AMs attach onto unmodified surfaces with a greater degree of spreading, than on the modified EPR. Samples grafted between 0.7 mg/cm2 and 1 mg/cm2 showed fairly low AM density compared with both unmodified EPR and lightly modified samples (less than 0.2 mg/cm2). AMs cultured on the unmodified EPR were larger and displayed pronounced ruffling of the plasma membrane, an increased capacity for adherence and spreading on the surface, and an increased number of extensive filopodia. Moreover, AMs attached onto the surface of modified samples appeared rounded, with minimal cytoplasmic spreading and ruffling.

Biological evaluation of biomaterials for cardiovascular applications: some current results.

The proper biologic evaluation of biomaterials for blood-contacting applications must include considerations of hemorheologic parameters, species-related differences, and damages to the reticuloendothelial system. Although there are no materials currently available that are completely blood compatible, several smooth-surfaced polymers are quite tolerable in the physiological environment. These include chemically grafted polyacrylamide hydrogels, glow-discharge polymers of silica-free hexamethldisiloxane, and ethyl cellulose perfluorobutyrate.