101,940 research outputs found

    Fluorescent Cell Barcoding for Immunophenotyping

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    Immunophenotyping using flow cytometry highly benefits from multiplexing samples for generation of more robust data, because of reduction of antibody consumption, batch effect and technical variations. One way to multiplex is via fluorescent cell barcoding (FCB) prior to staining procedure. FCB is a high-throughput multiplexed assay using various concentrations of different fluorescent dyes. Individual samples are uniquely labeled, then mixed together, stained and analyzed as a single sample, decreasing technical variations and increasing throughput and speed of acquisition. In addition, FCB simplifies implementation of normalization using a bridge control sample. In this chapter, we illustrate the protocol for FCB and recommendations for choosing barcoding dyes and concentrations among other technical considerations

    LC-HRMS/MS for the simultaneous determination of four allergens in fish and swine food products

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    The inclusion on the label of packed foods of any ingredient or technological adjuvant causing allergies is required by EU food legislation. In this study a targeted proteomics method for detecting four allergens in animal-derived food matrices was developed. Liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS/MS) was used to select marker peptides from four allergens and develop a quantitative method able to simultaneously detect the presence of milk, egg, crustaceans and soy. The method was validated on fish or swine processed food products contaminated at 5 μg g−1 for milk and egg and 10 μg g−1 for soy and crustaceans. The method was tested by analyzing commercial food products with high protein content and was compared to the ELISA technique. Our results indicated the presence of soy not reported on the food label of some products, pointing out the need for efficient controls to protect allergic consumers

    Is the Coming Out of an LGBTQIA+ Child a Death-like Event for Italian Parents?

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    Parents of LGBTQIA+ individuals often report experiencing an affective state similar to grief after their children's coming out. The current study explores whether this experience resembles that of people who have recently lost someone close. Furthermore, we tested whether the parents' alexythimic traits are associated with their grief-like experience. In a sample of 194 parents who experienced their children's coming out, we administered the Integration of Stressful Life Events Scale (ISLES), the Social Meaning In Life Events Scale (SMILES), and the Toronto Alexithymia Scale (TAS-20). The results showed no significant differences in the mean scores of ISLES and SMILES between the present and bereaved samples by their creators. In addition, in the present sample, lower ISLES and SMILES scores were associated with higher alexithymic traits. Overall, these findings suggest a resemblance between the experience of parents following their children's coming out and that of bereaved individuals. Therefore, they could inform on how to assist parents in coming to terms with the coming out of an LGBTQIA+ child

    Doxycycline and sulfadimethoxine transfer from cross-contaminated feed to chicken tissues.

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    During feed preparation at feed mills or during feed mixing in bins at farms, the accidental contamination of feed at trace levels by veterinary drug residues, commonly known as carry-over, can accidentally but frequently occur. To evaluate the concentrations of residual antimicrobials in poultry edible tissues, due to contaminated feed, sulfadimethoxine and doxycycline were administered for 10 days to chickens in poultry feed incurred at the contamination levels frequently found during national feed monitoring programmes (1-5 mg kg(-1)). Sulfadimethoxine and doxycycline residual concentrations detected in muscle (<LOD and 31 μg kg(-1), respectively), liver (13 and 56 μg kg(-1), respectively) and kidney (56 and 115 μg kg(-1), respectively) were compared with their maximum residue limits (MRLs) fixed by EC 470/2009 and EU 37/2010 Regulations for a preliminary risk evaluation

    Utility of isolated hepatocytes and radio-HPLC-MSn for the analysis of the metabolic fate of 19-nortestosterone laurate in cattle.

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    The metabolic fate of 19-nortestosterone laurate in cattle was investigated to evaluate target analyte(s) appropriate to surveillance for illicit use as a growth promoting agent. Bovine hepatocytes were incubated with either [3H]19-nortestosterone laurate (19-NTL; 4-estren-17 beta-laurate-3-one) or [3H]19-nortestosterone (19-NT; 4-estren-17 beta-ol-3-one; nandrolone). Hepatocyte medium was extracted with solid phase C18 media and analysed by narrow bore radio-HPLC-MSn (LCQ, Finnigan) to evaluate the structure of metabolites of 19-NTL and 19-NT. Radio-HPLC of hepatocyte medium extracts following incubation with [3H]19-NTL confirmed that the first step of biotransformation in liver was hydrolysis of the fatty acid ester to release [3H]19-NT, which, in turn, was converted into a range of metabolites of diverse polarity. Hydrolysis of hepatocyte medium extracts with beta-glucuronidase (Helix pomatia) indicated that some of these metabolites were glucuronide or sulfate conjugates. Structural analysis of unconjugated metabolities by positive-ion atmospheric pressure chemical ionisation MS2 and comparison with available reference preparations indicated biotransformation of 19-NT to 4-estren-17 alpha-ol-3-one, 4-estren-3, 17-dione (major metabolite after 1 h), n-hydroxy-4-estren-3, 17-dione, n-hydroxy-4-estren-17-ol-3-one, 5 beta-estran-3 alpha-ol-17-one (noretiocholanolone) and 5 beta-estran-3 alpha, 17 beta-ol (major metabolite after 4 h). Conjugated metabolites were analysed by electrospray ionization, which revealed the presence of glucuronide conjugates of alpha-(trace) and beta-epimers of 19-NT, n-hydroxy-4-estren-3, 17-dione, n-hydroxy-4-estren-17-ol-3-one and 5 beta-estran-3 alpha, 17 beta-diol. These studies provide a clear indication of the route of hepatic metabolism in the bovine, which may now be readily substantiated by reference to samples, such as urine or bile, derived from animals treated with unlabelled 19-NTL

    Metabolism of tilmicosin by rabbit liver microsomes and hepatocytes

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    We investigated tilmicosin (TIM) metabolism, at 25, 50 or 100 microM, in cultures of primary hepatocytes from rabbits bred commercially for food and in liver microsomes prepared from both untreated and rifampicin (RIF)-treated rabbits. RIF is a well-known cytochrome P4503A (CYP 3A) inducer in rabbits and most macrolides are known to be substrates of CYP 3A. No peaks in addition to those of the cis and trans forms of TIM were observed by high performance liquid chromatography (HPLC) in extracts of microsomes from untreated rabbits. When TIM was incubated with induced microsomes, at least two peaks were found by HPLC and an additional peak, eluting at shorter retention time was isolated from hepatocytes incubated for 24h with the macrolide. The structures of the metabolites were then estimated by liquid chromatography-mass spectrometry (LC-MS) in concentrated extracts from induced microsomes. Five metabolites were separated and putatively identified: cis and trans demethylated tilmicosin, tilmicosin N-oxide and cis and trans tilmicosin epoxide. The overall amount of metabolites produced in vitro using livers of untreated and RIF treated rabbits was very low, has also been observed in vivo and in vitro in cattle, chickens and pig

    In vitro metabolism of Clenbuterol and Bromobuterol using microsomes from swine liver

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    1. Clenbuterol (CBL) and bromobuterol (BBL) were both extensively metabolized by hepatic microsomes of swine to only one polar metabolite which was separated by hplc and purified to perform mass analysis. 2. LC-MIS analysis by direct infusion into an ion trap system and after reverse-phase chromatograpy into a triple quadrupole system showed that the metabolites were the hydroxylamine-derivatives of CBL and BBL. GC-MS analysis by the CI and EI modes confirmed that the hydroxyl group was bound to the aniline nitrogen. The chemical instability of those metabolites probably as a consequence of spontaneous oxidation and reduction gave rise during the analysis to the corresponding nitroso and nitro derivatives, together with the original compound. 3. Thermal inactivation and CO complex formation were used selectively to inactivate flavin monooxygenase and cytochrome P450, respectively. Both inactivation procedures significantly reduced the formation of the hydroxyl metabolite
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