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Fluorescence polarization immunoassay (FPIA) is a homogeneous and rapid analytical method that is suitable for high-throughput screening of large numbers of samples. However, FPIA typically suffers from lower sensitivity than the well-established enzyme-linked immunosorbent assay (ELISA), limiting its wide application as an analytical tool that can be run with trace levels of an analyte. Herein, a highly sensitive FPIA for detecting amantadine (AMD) in chicken is described. To achieve high sensitivity, nine chemical tracers of AMD that employ different fluoresceins, fluorescein derivatives, and haptens were synthesized and paired with four previously produced monoclonal antibodies (mAbs). The effect of the tracer structure on the sensitivity of FPIA was investigated and discussed. We found that the tracers with a linear and shorter bridge between adamantane and fluorescein generally provided higher sensitivity. After optimization, N'-(1-adamantyl) ethylenediamine (AEDA), an AMD structural analogue labeled with fluorescein isothiocyanate (FITC), achieved the lowest IC50 value (1.0 ng/ml) in the FPIA, which was comparable to that of the heterologous ELISA format that used the same mAb7G2. We also investigated the possible recognition mechanism of mAbs in terms of conformational and electronic aspects. The developed FPIA was applied to chicken to detect AMD residue, demonstrating a limit of detection (LOD) of 0.9 µg/kg with recoveries of 76.5-89.3% and coefficients of variation (CVs) below 14.5%. These results show that the proposed FPIA is an efficient, accurate, and convenient method for the rapid screening of AMD residues in chicken. PRACTICAL APPLICATION: The fluorescence polarization immunoassay (FPIA) was developed to determine and quantify amantadine (AMD) in chicken samples with high sensitivity. This homogeneous method avoids coating and washing steps and may provide high-throughput AMD screening in chicken in 10 min with high accuracy and precision. FPIA can be used as a monitoring tool and contribute significantly to the rapid detection of AMD in chicken.

The dominance effect is a kind of non-additive effect due to the interaction between alleles at the same locus. Quantitative traits such as growth traits in farm animals have been found to be influenced by dominance effects. However, dominance effects are usually ignored in the genome-wide association study (GWAS) of complex traits for farm animals. In this study, we performed GWAS and genetic parameters estimation for the two traits age at 100 kg (AGE) and backfat thickness at 100 kg (BF) of 3572 Large White pigs. The pigs were from three breeding farms of China and were genotyped by an in-house designed 50k SNP chip. Our results showed significant non-zero variance for the dominance effect of AGE, while the dominance effect of BF was not significant. Using a GWAS model accounting for both additive and dominance effects, we identified three additive and two dominance significant SNPs for the trait AGE. For the trait BF, three genome-wide significant additive SNPs were detected, but no significant SNP was found for the dominance effect. In total, six important functional genes (NPAS3, USP16, PARN, ARL15, GPC3, ABHD4) near significant SNPs were identified as candidate genes associated with AGE or BF. Notably, ARL15 and PARN were associated with AGE near the dominance association signals. Overall, the newly detected SNPs and newly identified candidate genes in our study added new information about the genetic architectures of growth and fatness traits in pigs, and have the potential to be applied to the pig breeding program in the future.

The pharmacokinetic behaviours of amoxicillin (AMX) and clavulanic acid (CA) in swine were studied after either an intravenous or oral administration of AMX (10 mg/kg) and CA (2.5 mg/kg). The concentrations of these two medicines in swine plasma were determined using high-performance liquid chromatographic-tandem mass spectrometry, and the data were analysed using a noncompartmental model with the WinNonlin software. After intravenous administration, both substances were absorbed rapidly and reached their effective therapeutic concentration quickly. CA was eliminated more slowly compared with AMX. Moreover, the distribution volume of AMX was larger than that of CA, suggesting that AMX could penetrate tissues better. After oral administration of the granular formulation, no significant difference was observed in the mean elimination half-life value between AMX and CA. The mean maximal plasma concentrations of AMX and CA, reached after 1.14 and 1.32 hr, were 2.58 and 1.91 μg/m, respectively. The mean oral bioavailability of AMX and CA was 23.6% and 26.4%, respectively. After oral administration, the T>MIC50 for three common respiratory pathogens was over 6.12 hr. Therefore, oral administration could be more effective in the clinical therapy of pigs, especially when administered twice daily.

The pharmacokinetic properties of three formulations of vitacoxib were investigated in horses. To describe plasma concentrations and characterize the pharmacokinetics, 6 healthy adult Chinese Mongolian horses were administered a single dose of 0.1 mg/kg bodyweight intravenous (i.v.), oral paste, or oral tablet vitacoxib in a 3-way, randomized, parallel design. Blood samples were collected prior to and at various times up to 72 hr postadministration. Plasma vitacoxib concentrations were quantified using UPLC-MS/MS, and pharmacokinetic parameters were calculated using noncompartmental analysis. No complications resulting from the vitacoxib administration were noted on subsequent administrations, and all procedures were tolerated well by the horses throughout the study. The elimination half-life (T1/2λz ) was 4.24 ± 1.98 hr (i.v.), 8.77 ± 0.91 hr (oral paste), and 8.12 ± 4.24 hr (oral tablet), respectively. Maximum plasma concentration (Cmax ) was 28.61 ± 9.29 ng/ml (oral paste) and 19.64 ± 9.26 ng/ml (oral tablet), respectively. Area under the concentration-versus-time curve (AUClast ) was 336 ± 229 ng hr/ml (i.v.), 221 ± 94 ng hr/ml (oral paste), and 203 ± 139 ng hr/ml, respectively. The results showed statistically significant differences between the 2 oral vitacoxib groups in Tmax value. T1/2λz (hr), AUClast (ng hr/ml), and MRT (hr) were significantly different between i.v. and oral groups. The longer half-life observed following oral administration was consistent with the flip-flop phenomenon.

The pharmacokinetics of carbetocin, which is used to control postpartum hemorrhage after giving birth, was studied in cows and gilts after a single intravenous (IV) or intramuscular (IM) injection. Blood samples from animals were assessed by oxytocin radioimmunoassay, and then the pharmacokinetic parameters were calculated using a noncompartmental model. For gilts, there was no significant difference between half-life (T1/2λZ ), mean residue time (MRT), and maximum concentration (Cmax ) between IM and IV administration. Conversely, the time to reach the Cmax (Tmax ) and MRT were higher following administration of 350 μg/animal in cows via the IM administration compared with IV. The longest T1/2λZ was 0.85 hr, indicating carbetocin was absorbed and eliminated rapidly in both animal species after administration. The Tmax was similar between cows and gilts following IM administration. Moreover, the Cmax after IM injection was about half that of IV administration in both animals. The bioavailability was more than 80% in cows, suggesting administration via the IM route is efficient. This is in agreement with the longer T1/2λZ in cows after IM administration. However, the IV route is recommended for gilts due to a lower bioavailability (35%) and shorter T1/2λZ after IM administration compared with IV.

Deep eutectic solvents (DESs) were applied as eco-friendly solvents in this study for the extraction of alkaloids from lotus leaf, including O-nornuciferine, N-nornuciferine, nuciferine and roemerine. A series of hydrophilic and hydrophobic DESs with different hydrogen bond donors and a acceptors were synthesized and screened for a suitable DESs for extraction of alkaloids from lotus leaf. The study results showed that the hydrophilic DES with choline chloride and propanediol had the highest extraction yield. The main factors affecting the extraction efficiency-choline chloride-propanediol ratio, water content in deep eutectic solvents, solid-liquid ratio and extraction time-were investigated via a single-factor experiment. The optimized extraction conditions were 30% of water in choline chloride-propanediol (1:4) for heated extraction for 30 min and solid-liquid ratio 1:100 g/ml. Under optimum conditions, the extraction yields of O-nornuciferine, N-nornuciferine, nuciferine and roemerine were 0.069, 0.152, 0.334 and 0.041 g/100 g respectively, which were higher than those of methanol in acidified aqueous solution. This study suggests considerable potential for DESs as promising materials for the green and efficient extraction solvents for bioactive alkaloids from natural sources.

Altrenogest, a synthetic progestogen, is characterized by its estrus synchronization in mares, ewes, sows, and gilts. To investigate the pharmacokinetic profile and evaluate its accumulation in gilts, 18 oral doses of 20 mg altrenogest/gilt/day were given to eight healthy gilts at an interval of 24 hr. Plasma samples were collected, and altrenogest was determined by ultra-high-performance liquid chromatography with mass spectrometry. WinNonlin 6.4 software was used to calculate the pharmacokinetic parameters through noncompartmental model analysis. After the first administration (D 1), the pharmacokinetic parameters, including Tmax , Cmax , and the elimination half-life (T1/2λz ), were similar to those observed after the final administration (D 18). However, the mean residence time at D 1 was significantly lower than D 18. As a whole, the mean steady-state plasma concentration (Css ), degree fluctuation (DF), accumulation factor (Rac ), and area under the plasma concentration-time curve in steady state (AUCss ) were 22.69 ± 6.15 ng/ml, 270.64 ± 42.51%, 1.53 ± 0.23, and 544.63 ± 147.49 ng hr/ml, respectively. These results showed that after 18 consecutive days of oral administration of altrenogest, plasma concentrations of altrenogest had a certain degree of fluctuation, without significant accumulations.

The pharmacokinetic parameters of moxidectin (MXD) after intravenous and pour-on (topical) administration were studied in sixteen pigs at a single dose of 1.25 and 2.5 mg/kg BW (body weight), respectively. Blood samples were collected at pretreatment time (0 hr) over 40 days. The plasma kinetics were analyzed by WinNonlin 6.3 software through a noncompartmental model. For intravenous administration (n = 8), the elimination half-life (λZ ), the apparent volume of distribution (Vz ), and clearance (Cl) were 10.29 ± 1.90 days, 89.575 ± 29.856 L/kg, and 5.699 ± 2.374 L/kg, respectively. For pour-on administration (n = 8), the maximum plasma drug concentration (Cmax ), time to maximum plasma concentration (Tmax ), and λZ were 7.49 ng/ml, 1.72, and 6.20 days, respectively. MXD had a considerably low absolute pour-on bioavailability of 9.2%, but the mean residence time (MRT) for pour-on administration 10.88 ± 1.75 days was longer than 8.99 ± 2.48 days for intravenous administration. These results showed that MXD was absorbed via skin rapidly and eliminated slowly. The obtained data might contribute to refine the dosage regime for topical MXD administration.

The pharmacokinetic properties of vitacoxib have not been established completely; current dosage recommendations are based on clinical experiences. The primary objective of this study was to describe plasma concentrations and characterize the pharmacokinetics of vitacoxib formulation following oral administrations in horses. Also, the effect of the state of stomach contents on the absorption of vitacoxib was investigated in fed/fasted horses. Blood samples were collected prior to and at various times up to 72 hr post-administration. Drug concentrations were measured using ultra high-performance liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated using Non-Compartmental Analysis Model 200 in WinNonlin™ software. No complications resulting from the vitacoxib administration were noted. All procedures were tolerated well by the horses throughout the study. Cmax was 17.5 ± 9.36 ng/ml (fasted) and 9.47 ± 3.53 ng/ml (fed) following oral administrations. AUClast was 173.7 ± 137.9 ng hr/ml (fasted) and 113.2 ± 70.8 ng h/ml (fed). No significant differences in pharmacokinetic parameters were noted and the results from the pharmacokinetic analysis were similar between the studies, regardless of precision of dosage and fasted and fed conditions. The study extends previous studies describing the pharmacokinetics of vitacoxib following p.o. administration to the horses. Further studies investigating the pharmacokinetics/pharmacodynamics of vitacoxib are necessary to establish adequate therapeutic protocols (optimal dosage and frequency of administration) in horses.

Ceftiofur (CEF), a broad-spectrum third-generation cephalosporin, exhibits a good activity against a broad range of gram-negative and gram-positive bacteria, including many that produce β-lactamase. To design a rational dosage regimen for the drug in lactating Holstein dairy cows, the pharmacokinetic properties of ceftiofur hydrochloride injection were investigated in six cows after intravenous, intramuscular, and subcutaneous administration of single dose of 2.2 mg/kg BW (body weight). Plasma concentration-time curves and relevant parameters were best described by noncompartmental analysis through WinNonlin 6.3 software. After subcutaneous administration, the absolute bioavailability was 61.12% and the T1/2λz (elimination half-life) was 8.67 ± 0.72 hr. The Cmax (maximum plasma concentration) was 0.88 ± 0.21 μg/ml and Tmax (the time after initial injection to when Cmax occurs) was 1.50 ± 0.55 hr. The MRT (mean residence time) was 11.00 ± 0.30 hr. Following intramuscular administration, the Cmax (1.09 ± 0.21 μg/ml) was achieved at Tmax (1.20 ± 0.26 hr) with an absolute availability of 70.52%. In this study, the detailed pharmacokinetic profiles of free and total CEF showed that this drug is widely distributed and rapidly eliminated and may contribute to a better understanding of the usage of ceftiofur hydrochloride injection in Holstein dairy cows.

The objective of this study was to investigate the pharmacokinetic profile of tildipirosin (TD) in 24 beagle dogs following intravenous (i.v.) and intramuscular (i.m.) administration, respectively, at 2, 4, and 6 mg/kg. Plasma samples at certain time points (0-14 days) were collected, and the concentrations of drug were quantified by UPLC-MS/MS. Plasma concentration-time data and relevant parameters were described by noncompartmental through WinNonlin 6.4 software. After single i.m. injection at 2, 4, and 6 mg/kg body weight, mean maximum concentration (Cmax ) was 412.73 ± 76.01, 1,051 ± 323, and 1,061 ± 352 ng/ml, respectively. Mean time to reach Cmax was 0.36 ± 0.2, 0.08 ± 0.00, and 0.13 ± 0.07 hr after i.m. injection at 2, 4, and 6 mg/kg, respectively. The mean value of T1/2λz for i.m. administration at doses of 2, 4, and 6 mg/kg was 71.39 ± 28.42, 91 .33 ± 50.02, and 96.43 ± 45.02 hr, respectively. The mean residence times were 63.81 ± 10.96, 35.83 ± 15.13, and 38.18 ± 16.77 hr for doses of 2, 4, and 6 mg/kg, respectively. These pharmacokinetic characteristics after i.m. administration indicated that TD could be rapidly distributed into tissues on account of the high lipid solubility and then released into plasma. In addition, the absolute bioavailability of 2 mg/kg after i.m. injection was 112%. No adverse effects were observed after i.v. and i.m. administration.

Mucoepidermoid carcinoma of the gastrointestinal tract is a rare entity. Here, we report a case of mucoepidermoid carcinoma of the transverse colon in a 77-year-old woman who presented with a 2-month history of epigastrium pain, diarrhea and melena. A giant tumor with apparently invading gallbladder was found by enhanced CT scan, then the extended resection of transverse colon was performed for the patient 2 weeks later. Microscopically, the tumor was composed of solid nests of epidermoid and Periodic Acid-Schiff (PAS)-positive mucin-producing cells with desmoplastic stroma. The epidermoid component of the tumor contained intercellular bridges and individual cell keratinization. Thus, the case was diagnosed as mucoepidermoid carcinoma of the transverse colon. Unfortunately, despite chemotherapy, the patient developed systemic failure and died 7 months postoperatively.

The pharmacokinetic characteristics of valnemulin in layer chickens were studied after single intravenous, intramuscular, and oral administration at a dose of 15 mg/kg body weight. Plasma samples at certain time points were collected and the drug concentrations in them by ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS). The concentration–time data for each individual were plotted by noncompartmental analysis for the whole three routes. Following intravenous administration, the plasma concentration showed tiny fluctuation. The elimination half-life (T1/2λz), total body clearance (Cl), and area under the plasma concentration–time curve (AUC) were 1.85 ± 0.43 h, 2.2 ± 0.9 L/h, and 7.52 ± 2.46 μg·h/mL, respectively. Following intramuscular administration, the peak concentration (Cmax, 1.40 ± 0.43 μg/mL) was achieved at the time of 0.34 h. A multiple-peak phenomenon existed after oral administration, and the first peak and secondary peak were at 10 min and during 2–4 h, respectively, while the tertiary peak appeared during 5–15 h. The bioavailability (F %) for intramuscular and oral administration was 68.60% and 52.64%, respectively. In present study, the detailed pharmacokinetic profiles showed that this drug is widely distributed and rapidly eliminated, however has a low bioavailability, indicating that valnemulin is likely to be a favorable choice in the clinical practice.

Laboratory experiments were conducted to determine (a) the baseline sensitivity of Rhizoctonia solani to thifluzamide and (b) the risk of the fungus developing resistance to the fungicide. Thifluzamide sensitivity was assessed for 227 isolates of R. solani collected from 12 provinces of China from 2007 to 2011. One insensitive isolate GD-1 was obtained from the field, and the EC50 values of the 226 sensitive isolates had a unimodal frequency distribution with a mean of 0.0351 µg mL−1. Nine resistant mutants were generated using thifluzamide-amended media or UV radiation in the laboratory. The resistance was stable for all mutants after 10 transfers on PDA medium. Fitness of the most resistant mutants was lower than that of the sensitive isolates, implying a lower competitiveness of the mutants relative to sensitive isolates in field. Cross-resistance was detected between thifluzamide and the Succinate dehydrogenase inhibitors (SDHIs) fenfuram, carboxin, penflufen and boscalid, but not between thifluzamide and difenoconazole, carbendazim, propiconazol, SYP-2815 (quinone outside inhibitor (QoI) fungicide developed in China), fluazinam, jinggangmycin, pyrimorph or mepronil. The SDHI fungicide fluopyram did not inhibit R. solani. Taken together, these results suggest that the risk of R. solani developing resistance to thifluzamide is low to moderate.

The stearoyl-CoA desaturase (delta-9-desaturase) gene encodes a key enzyme in the cellular biosynthesis of monounsaturated fatty acids. In our initial genome-wide association study (GWAS) of Chinese Holstein cows, 19 SNPs fell in a 1.8-Mb region (20.3-22.1 Mb) on chromosome 26 underlying the SCD gene and were highly significantly associated with C14:1 or C14 index. The aims of this study were to verify whether the SCD gene has significant genetic effects on milk fatty acid composition in dairy cattle. By resequencing the entire coding region of the bovine SCD gene, a total of six variations were identified, including three coding variations (g.10153G>A, g.10213T>C and g.10329C>T) and three intronic variations (g.6926A>G, g.8646G>A and g.16158G>C). The SNP in exon 3, g.10329C>T, was predicted to result in an amino acid replacement from alanine (GCG) to valine (GTG) in the SCD protein. An association study for 16 milk fatty acids using 346 Chinese Holstein cows with accurate phenotypes and genotypes was performed using the mixed animal model with the proc mixed procedure in sas 9.2. All six detected SNPs were revealed to be associated with six medium- and long-chain unsaturated fatty acids (P = 0.0457 to P

Our previous RNA sequencing experiment showed that the serum amyloid A2 (SAA2) gene was one of the most promising candidates for milk protein and fat traits in dairy cattle. The SAA2 gene encodes an apolipoprotein related to high-density lipoproteins. To further validate its genetic effects, genotype-phenotype associations were performed in this study. Through resequencing of the entire coding region and the 5'-regulatory region of the SAA2 gene using pooled DNA of 12 unrelated sires, one novel 3-bp insertion-deletion and five previously reported SNPs were detected. These identified SNPs were genotyped and tested for association with five milk production-related traits in 717 Chinese Holstein cows. After Bonferroni correction for multiple t-tests, five of them were found to be statistically significant for milk yield, fat yield and protein yield (P 0.0001~0.0053). Haplotype-based association analysis revealed a similar effect on fat yield and protein yield (P = 0.0005, P = 0.0032 respectively). Then, using luciferase report assay, the regulatory effect of the three SNPs located in the promoter region (c.-22GA; c.17GC; c.114GA) was evaluated on transcriptional activity. In HEK-293 cell lines, we found that constructs GCG and AGG showed higher luciferase activity compared with GCA (P 0.01, P 0.01 respectively). Meanwhile, the prediction of the putative differential transcription factor binding site revealed that c.17GC and c.114GA caused the alteration in the transcription factor. Overall, the findings presented here provide the first evidence for associations of the SAA2 gene with milk fat and protein traits, which appears to be a key candidate for milk production traits in dairy cattle.

Odorant-binding proteins (OBPs) play an important role in insect olfactory processes and are thought to be responsible for the transport of pheromones and other semiochemicals across the sensillum lymph to the olfactory receptors within the antennal sensilla. As an important general odorant binding protein in the process of olfactory recognition, LstiGOBP1 of Loxostege sticticalis L. has been shown to have good affinity to various plant volatiles. However, the binding specificity of LstiGOBP1 should be further explored in order to better understand the olfactory recognition mechanism of L. sticticalis. In this study, real-time PCR experiments indicated that LstiGOBP1 was expressed primarily in adult antennae. Homology modelling and molecular docking were then conducted on the interactions between LstiGOBP1 and 1-heptanol to understand the interactions between LstiGOBP1 and their ligands. Hydrogen bonds formed by amino acid residues might be crucial for the ligand-binding specificity on molecular docking, a hypothesis that was tested by site-directed mutagenesis. As predicted binding sites for LstiGOBP1, Thr15, Trp43 and Val14 were replaced by alanine to determine the changes in binding affinity. Finally, fluorescence assays revealed that the mutants Thr15 and Trp43 had significantly decreased binding affinity to most odours; in mutants that had two-site mutations, the binding to the six odours that were tested was completely abolished. This result indicates that Thr15 and Trp43 were involved in binding these compounds, possibly by forming multiple hydrogen bonds with the functional groups of the ligands. These results provide new insights into the detailed chemistry of odours' interactions with proteins.

The pharmacokinetics and bioavailability of butafosfan in piglets were investigated following intravenous and intramuscular administration at a single dose of 10 mg/kg body weight. Plasma concentration-time data and relevant parameters were best described by noncompartmental analysis after intravenous and intramuscular injection. The data were analyzed through WinNolin 6.3 software. After intravenous administration, the mean pharmacokinetic parameters were determined as T1/2λz of 3.30 h, Cl of 0.16 L kg/h, AUC of 64.49 ± 15.07 μg h/mL, Vss of 0.81 ± 0.44/kg, and MRT of 1.51 ± 0.27 h. Following intramuscular administration, the Cmax (28.11 μg/mL) was achieved at Tmax (0.31 h) with an absolute availability of 74.69%. Other major parameters including AUC and MRT were 48.29 ± 21.67 μg h/mL and 1.74 ± 0.29 h, respectively.

The cDNA-AFLP (amplified fragment length polymorphism) technique was performed to detect transcript-derived fragments related to drought tolerance in maize inbred lines X178 and B73 to identify and understand drought-responsive genes at the transcriptional level. By comparing the sequences of fragments differentially expressed between these lines under water-stressed and well-watered conditions, 72 drought-responsive unique expressed sequence tags (ESTs) were identified with 41 primer combinations targeting PstI/MseI restriction sites. Most of the fragments isolated in these experiments were found to be associated with genes responsive to abiotic or biotic stresses. Subsequently, a putative R1-type MYB transcription factor gene corresponding to ZmMYB-R1 on bin 9.03 was obtained by in silico cloning by homology to EST sequence P36M87-366, which matched one of the AFLPs identified in this study. The 1881 bp sequence encodes a protein of 626 amino acids that contains a single conserved MYB-like DNA-binding domain. Expression of green fluorescence protein fusions showed that ZmMYB-R1 was localised in the cell nucleus. Quantitative real-time polymerase chain reaction revealed that ZmMYB-R1 was induced by drought, high salt, heat, cold and exogenous ABA in maize. The expression of ZmMYB-R1 initially reaches its highest levels in leaves, then is subsequently also detected in stems and roots. This work revealed genes potentially responsible for drought tolerance in maize, and a new gene, ZmMYB-R1, was shown to be associated with water stress.

Quinocetone (QCT), 3-methyl-2-cinnamoylquinoxaline-1,4-dioxide, is a quinoxaline-N,N-dioxide used in veterinary medicine as a feed additive. QCT is broadly used in China to promote animal growth, but few studies have been performed to reveal the metabolism of QCT in animals until now. In the present study, the metabolites of QCT in swine urine were investigated using ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-QTOF-MS). Multiple scans of metabolites in MS and MS/MS modes and accurate mass measurements were performed simultaneously through data-dependent acquisition. Most measured mass errors were less than ±5 mDa for both protonated molecules and product ions using external mass calibration. The structures of metabolites and their product ions were easily and reliably characterized based on the accurate MS2 spectra and known structure of QCT. As expected, extensive metabolism was observed in swine urine. Thirty-one metabolites were identified in swine urine, most of which were reported for the first time. The results reveal that the N-O group reduction at position 1 and the hydroxylation reaction occurring at the methyl group, the side chain or on the benzene ring are the main metabolic pathways of quinocetone in swine urine. There was abundant production of 1-desoxyquinocetone and hydroxylation metabolites of 1-desoxyquinocetone. The proposed metabolic pathway of quinocetone in vivo can be expected to play a key role in food safety evaluations. Copyright © 2010 John Wiley & Sons, Ltd.

The hairs on the wings of Locusta migratoria were observed and mapped using light microscopy, as well as by scanning and transmission electron microscopy. Based on their ultrastructure, we can distinguish four main types of hairs on the wings of adult L. migratoria, viz, short, medium and long hairs, and sensilla chaetica. The long hairs are located only on the ventral surface of the hindwing, whereas the other three types are present both on the dorsal and ventral surfaces of forewing and hindwing in both sexes. Medium hairs and sensilla chaetica are significantly more abundant on the dorsal surface of forewings in both females and males, than on the ventral surface, whereas the opposite was observed for short hairs (P 0.1). Several dendritic branches, enveloped by a dendrite sheath, are situated in the lymph cavity of sensilla chaetica. Instead, no dendritic structure was observed in the cavity of the othe' three types of hairs. Immunocytochemical localization of chemosensory proteins (CSPs) was performed on ultrathin sections of hairs on wings. The antiserum against chemosensory proteins from L. migratoria (LmigCSP-II) strongly labelled sensilla chaetica, with gold granules only found in the outer sensillum lymph. In addition, the epidermal cell membrane of the wing was stained by the antiserum against LmigCSP-II. The other three types of hairs were never labelled. The results indicate that the wings might involve in contact chemoreception process.

Summary A fluorescence polarisation immunoassay (FPIA) using a specific polyclonal antiserum for the detection of maduramicin (MD) was developed and optimised. The polyclonal antiserum was produced against MD linked to bovine serum albumin. Fluorescein-labelled MD (tracer) was synthesised by N-hydroxysuccinimide active ester method and purified using thin layer chromatography. The developed FPIA for MD had a dynamic range from 0.01 to 5.6 μg mL−1 with an IC50 value of 0.16 μg mL−1 and a limit of detection of 0.002 μg mL−1. Recoveries from chicken muscle, fat and egg samples spiked at 0.25, 5 and 10 μg g−1 levels were 82–130%. The FPIA results from analysis of incurred residues in chicken muscle samples showed that the simple procedure is viable.

Summary A fluorescence polarisation immunoassay (FPIA) for the screening of sulphamethazine (SMZ) in chicken muscle was developed. Fluorescein-labelled tracers for several sulphonamides were synthesised and monoclonal antibodies (Mabs) and polyclonal antibody (Pab) were produced. The Mabs and Pabs were raised against sulphonamides conjugated to bovine serum albumin by a diazo method. The most sensitive FPIA method for SMZ detection was based on a combination of the Mab against SMZ–bovine serum albumin and tracer SMZ labelled with fluorescein isothiocyanate. The limit of detection and IC50 for SMZ were 1 and 16 ng mL−1. Recoveries of SMZ from fortified chicken muscle samples averaged between 78% and 89%. The proposed FPIA method was applied for determining SMZ in an actual residue study.

A novel nitrite sensor was developed based on the immobilization of a partially quaternized poly(4-vinylpyridine) complexed with [Os(bpy)2Cl]+/2+ (PVP-Os) in a porous TiO2 sol-gel matrix by a vapor deposition method. The preparation process simplified the traditional sol-gel process and prevented the cracking of conventional sol-gel derived glasses. Electrochemical behavior of the sensor was characterized by cyclic voltammetry and shows excellent electrocatalytic response for the reduction of nitrite. Effect of operating potential on electrochemical responses of the sensor was explored for optimum analytical performance by using the amperometric method. The stability of the sensor was also evaluated.

A series of poly[(ether ether ketone)-co-(ether naphthalene ether ketone)] (P(EEK-co-ENEK)) copolymers were heated under a variety of conditions. The thermal crosslinking behavior was monitored by differential scanning calorimetry (DSC), electron spin resonance (ESR) and wide-angle X-ray diffraction (WAXD). The results indicate that under a non-oxidative environment such as nitrogen P(EEK-co-ENEK) is more stable, while under oxidative conditions a crosslinking reaction takes place that causes a reduction in the crystallizability of the copolymers, and an increase in the concentration of free radicals on the copolymer. ESR results suggest that the crosslinking reaction proceeds via free radicals. Subsequently two kinds of free radicals were characterized: one is an RO• type free radical and the other is a naphthalene ring free radical. Copyright © 2004 Society of Chemical Industry

The bioconcentration and elimination of avermectin B1 in sturgeon muscle were investigated with high-performance liquid chromatography. Mean concentrations of 0.2 and 1 ng x ml(-1) in water were maintained for a 22-d exposure period. The concentrations of avermectin B1alpha in muscle tissues reached steady state within 14 to 18 d. The level of avermectin B1 concentrations in the fish muscles was 7.75+/-0.88 and 38.29+/-1.65 ng x g(-1) for the low and high concentrations, respectively, on day 22. The half-life (t1/2) of the concentrations for the two treated groups was 4.95 and 4.33 d for the low and high concentrations, respectively. Greater than 95% of the tissue concentrations were eliminated from the exposed fish after the 14- and 18-d elimination periods. The estimated values of the bioconcentration factor were 42 L/kg for the low-concentration group and 41 L/kg for high-concentration group, and these values were not significantly different (alpha = 0.05). Avermectin B1alpha does not strongly bioconcentrate in individual aquatic organism and would not be expected to biomagnify in the food chain.