Determination of colchicine residues in sheep serum and milk using high-performance liquid chromatography combined with electrospray ionization ion trap tandem mass spectrometry

Colchicine is a naturally occurring alkaloid used in human and veterinary medicine. It shows genotoxicity in in vitro and in vivo systems even at low concentrations. Therefore, no ADI has been established, and colchicine has been included in Annex IV of Council Regulation (EEC) No. 2377/90. No abuse of this drug in intensive livestock farming has yet been reported. However, there may be a natural route of entry for this compound into the food chain when Colchicum autumnale is consumed by animals kept outdoors. To address this concern, we developed and validated a highly sensitive and selective quantitative LC-ESI-MS-MS method for the detection of colchicine in sheep serum and milk. For sample pretreatment, all samples were liquid-liquid extracted with phosphate buffer (pH 8.0) and dichloromethane. LC separation was carried out on an RP C18 column employing a 0.5% formic acid/acetonitrile gradient system. The recoveries in both matrixes at a concentration range from 0.0005 to 1 mg/L were >80% with RSDs of <10%. The applicability of the method was demonstrated in serum and the corresponding milk samples from Albanian sheep. After exposure to C. autumnale, the animals showed clinical signs of intoxication. Significant concentrations (up to 1 mg/L) of the drug were found in serum as well as in milk samples.     

Properties of frying fat. I. The relationship of viscosity to the concentration of non-urea adducting fatty acids

The extent of the thermal oxidative change in commercial frying fats as measured by the amount of non-urea adducting fatty acids formed in the fat and the viscosity of the fat was compared. A direct and highly significant relationship was found. The relationship was found to be dependent upon the source and processing of the fat as well as the conditions of use. Presented at the AOCS Meeting in Chicago, October 1964.     

A reappraisal of the roles of past experience and innate organizing processes in visual perception.

This paper is an attempt to evaluate the controversy existing between those theories which emphasize the role of learning on perception and the theory which emphasizes the role of innate organizing processes on perception. The writers conclude "that various aspects of the phenomenal world and, in particular, the segregation and shape of visual forms are given by innate organizing processes. Percepts may be modified and enriched by experimental factors but the effects of such factors presuppose the prior existence of visual forms." 82 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermal Conductivity of AlN and SiC Thin Films

The thermal conductivity of AlN and SiC thin films sputtered on silicon substrates is measured employing the 3ω method. The thickness of the AlN sample is varied in the range from 200 to 2000 nm to analyze the size effect. The SiC thin films are prepared at two different temperatures, 20 and 500°C, and the effect of deposition temperature on thermal conductivity is examined. The results reveal that the thermal conductivity of the thin films is significantly smaller than that of the same material in bulk form. The thermal conductivity of the AlN thin film is strongly dependent on the film thickness. For the case of SiC thin films, however, increased deposition temperature results in negligible change in the thermal conductivity as the temperature is below the critical temperature for crystallization. To explain the thermal conduction in the thin films, the thermal conductivity and microstructure are compared using x-ray diffraction patterns.     

PDLCs and EPCs Co-Cultured on Ta Discs: A Golden Fleece for “Compromised” Osseointegration

Material research in tissue engineering forms a vital link between basic cell research and animal research. Periodontal ligament cells (PDLCs, P) from the tooth have an osteogenic effect, whereas endothelial progenitor cells (EPCs, E) assist in neovascularization. In the present study, the interaction of PDLCs and EPCs with Tantalum (Ta, I) discs, either alone (IP or IE group) or in 1:1 (IPE) ratio was explored. Additionally, surface analysis of Ta discs with respect to different types and cycles of sterilization and disinfection procedures was evaluated. It was observed that Ta discs could be used for a maximum of three times, after which the changes in properties of Ta discs were detrimental to cell growth, irrespective of the type of the protocol. Cell-Disc’s analysis revealed that cell proliferation in the IE group at day 6 and day 10 was significantly higher (p < 0.05) than other groups. A cell viability assay revealed increased live cells in the IPE group than in the IP or IE group. Similarly, adhesion and penetration of cells in the IPE group were not only higher, but also had an increased thickness of cellular extensions. RT-PCR analysis revealed that on day 8, both osteogenic (ALP, RUNX-2, and BSP) and angiogenic genes (VEGFR-2, CD31) increased significantly in the IPE group as compared to the IP or IE groups (p < 0.05). In conclusion, Ta discs promoted cellular proliferation and increased osteogenic and angiogenic activity by augmenting RUNX-2 and VEGFR-2 activity.