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Background: Infections after abdominal surgery remain a significant problem. Although preoperative antibiotic prophylaxis is a primary strategy used to reduce postoperative infections, it is typically prescribed based on standardized protocols, without attention to previous infection or antibiotic history. Patients with a previous infection after surgery may be at higher risk for infectious complications after subsequent operations owing to antibiotic resistance. We hypothesized that a previous postoperative infection is a significant risk factor for the development of infection after a second unrelated surgery.Study Design: We performed a retrospective study of patients who had undergone 2 unrelated abdominal operations at a tertiary care center from 2012 to 2018. Clinical variables and microbiological culture results were abstracted. Univariate and multivariable regression models were constructed.Results: Of 758 patients, 15.0% (n = 114) developed an infection after the first operation. After the second operation, 22.8% (n = 26) of those with a previous infection developed another infection, whereas the incidence of an infection after the second operation was only 9.5% (n = 61) in patients who did not develop an infection after the first operation. Multivariable analysis demonstrated that previous infection (odds ratio 2.49, 95% CI 1.46 to 4.25) was associated with future infection risk. Microbiological analysis found that infections after the second surgery were significantly more likely to be antibiotic resistant than infections after the first surgery (82.3% vs 64.1%; p = 0.036). Strikingly, 49% of infections after the second surgery were resistant to the antibiotic prophylaxis given at the time of incision.Conclusions: Previous postoperative infection is an independent risk factor for a subsequent postoperative infection and is associated with resistance to standard prophylaxis. Individualization of antibiotic prophylaxis in patients with a previous postoperative infection is warranted. [ABSTRACT FROM AUTHOR]

Aminorex has been reported as a metabolite of levamisole in man, but data on the aminorex concentrations in clinical samples are scant. We thus measured levamisole, aminorex and benzoylecgonine in urine, and levamisole and aminorex in plasma using achiral liquid chromatography-high resolution mass spectrometry. Centrifuged urine (50 μL) was diluted with LC eluent containing internal standard (benzoylecgonine-D3, 25 μg/L) (450 μL). For plasma, sample (200 μL) and Tris solution (2 mol/L, pH 10.6, 100 μL) were added to a 60.5 × 7.5 mm i.d. glass test tube. Internal standard solution (ketamine-D4, 200 μg/L) (10 μL) was added and the tube contents vortex-mixed (5 s). Butyl acetate:butanol (9 + 1, v/v ; 200 μL) was added and after vortex-mixing (30 s) and centrifugation (13,680 × g, 4 min), the extract was evaporated to dryness and reconstituted in 10 mmol/L aqueous ammonium formate containing 0.1% (v/v) formic acid (150 μL). Prepared samples and extracts (100 μL) were analyzed using an AccucoreTM Phenyl-Hexyl column (2.6 mm a.p.s. 100 × 2.1 mm i.d.) maintained at 40°C. MS detection was in positive mode using heated electrospray ionization (ThermoFisher Q-ExactiveTM). Intra- and inter-assay accuracy and precision were ±20%, and ≤11%, respectively, for all analytes in both matrices. Lower limits of quantitation were 0.1 and 1 μg/L (all analytes) in plasma and urine, respectively. Of 100 consecutive urine samples submitted for drugs of abuse screening containing benzoylecgonine, levamisole was detected in 72 (median 565, range 4–72,970 μg/L). Levamisole was also measured in eight plasma samples (median 10.6, range 0.9–64.1 μg/L). A number of metabolites of levamisole (4-hydroxylevamisole, levamisole sulfoxide, levamisole glucuronide, and hydroxylevamisole glucuronide) were tentatively identified in urine. Neither aminorex, nor any of its reported metabolites were detected in any sample. [ABSTRACT FROM AUTHOR]

In this article, two fatal cases related to the use of 3-methoxyphencyclidine (3-MeO-PCP) are described. This compound is a new psychoactive substance that belongs to the phencyclidine family. In the recent period, this dissociative drug has gained interest because of its proposal as a legally available alternative to phencyclidine in some countries. The scientific literature related to 3-MeO-PCP is very poor. Using standard ultra-performance liquid chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry, the authors focused on the detection of 3-MeO-PCP and its metabolites in human urine. 3-MeO-PCP metabolism was studied in vitro after drug incubation with human liver microsomes and the identified metabolites were investigated in the urine of the two forensic cases. 3-MeO-PCP metabolites, including O -demethyl-3-MeO-PCP, piperidine-hydroxy-3-MeO-PCP, O -demethyl-piperidine-di-hydroxy-3-MeO-PCP and piperidine-di-hydroxy-3-MeO-PCP, were detectable in the urine from both cases and the ratio between metabolites and parent 3-MeO-PCP, always lower than 1, were calculated to estimate the proportionality of metabolites. At this stage, one can conclude that testing for 3-MeO-PCP metabolites does not increase the window of detection of the drug. [ABSTRACT FROM AUTHOR]

Here, we describe the use of a fluorescence based lateral flow competition assay for the screening of four classes of drugs, viz, Δ9-tetrahydrocannabinol (THC), cocaine (through the detection of benzoylecgonine, BZE), opiates (through the detection of morphine, MOR) and amphetamine (AMP) present in the sweat of a fingerprint. The Drug Screening Cartridge was specifically developed for fingerprint sample collection and analysis. For this study, the cut-offs were set at: 190, 90, 68 and 80 pg/fingerprint for THC, BZE, MOR and AMP, respectively. Working with three UK coroners, the Drug Screening Cartridge, together with its fluorescence reader, was applied to the detection of drugs in the sweat of a fingerprint from deceased individuals. The study shows that there was sufficient sweat present on the fingertips to enable analysis and that the Drug Screening Cartridge could detect the presence, or absence, of each drug. The presence of the drugs was confirmed using LC–MS-MS analysis of a second fingerprint sample collected simultaneously. Excellent correlation was achieved between the results obtained from the Drug Screening Cartridge and the LC–MS-MS analysis of the fingerprint samples obtained from 75 individuals. The accuracy of the results was: 99% for THC; 95% for BZE; 96% for MOR and 93% for AMP. The results obtained using the Drug Screening Cartridge were also compared to toxicological analysis of blood and urine samples with good correlation. The accuracy of the results between the Drug Screening Cartridge and blood was: 96%, 92%, 88% and 97% for THC, BZE, MOR and AMP, respectively. The comparison with urine showed an accuracy ranging between 86% and 92%. This fingerprint sample method has a collection time of just 5 s and a total analysis time of <10 mins. These results show that the lateral flow Drug Screening Cartridge is an excellent screening test to provide information on drug use from the sweat in a single fingerprint sample. [ABSTRACT FROM AUTHOR]

A novel multilayer‐shaped CeO2 with obvious electrocatalytic activity was synthesized using a simple heat treatment method. The structure and morphology of the multilayer‐shaped CeO2 were characterized by X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. Clenbuterol, a kind of β‐agonist drugs, has recently become a serious issue to human body due to the illegal addition in the food additive for livestocks. The drug residue in the human body may cause muscular pain, cardiac palpitation, glaucoma, prostatitis, dizziness and and even death in old people. Therefore, the detection of clenbuterol (CLB) has a important significance. The as‐prepared CeO2 was found to have unique electrocatalytic oxidation activities towards clenbuterol (CLB). The electrochemical sensor was constructed by fixing stable nafion‐modified multilayer‐shaped CeO2 film on a glassy carbon electrode. Compared with the CeO2‐modified electrode and the nafion‐modified electrode, the nafion‐modified multilayer‐shaped CeO2 electrode showed better electrocatalytic performance for clenbuterol in HClO4 solution. There was a good linear relationship between the oxidation peak current and the concentration of CLB between 0.39∼2.79 μmol/L, and the detection limit was 0.08 μmol/L (R=0.99). The nafion‐modified multilayer‐shaped CeO2 electrode exhibited high stability and reproducibility. [ABSTRACT FROM AUTHOR]

Regulatory agencies and government authorities have established maximum residue limits (MRL) in various food matrices of animal origin for supporting governments and food operators in the monitoring of veterinary drug residues in the food chain, and ultimately in the consumer’s plate. Today, about 200 veterinary drug residues from several families, mainly with antibiotic, antiparasitic or antiinflammatory activities, are regulated in a variety of food matrices such as milk, meat or egg. This article provides a review of the regulatory framework in milk and muscle including data from Codex Alimentarius, Europe, the U.S.A., Canada and China for about 220 veterinary drugs. The article also provides a comprehensive overview of the challenge for food control, and emphasizes the pivotal role of liquid chromatography-mass spectrometry (LC-MS), either in tandem with quadrupoles (LC-MS/MS) or high resolution MS (LC-HRMS), for ensuring an adequate consumer protection combined with an affordable cost. The capability of a streamlined LC-MS/MS platform for screening 152 veterinary drug residues in a broad range of raw materials and finished products is highlighted in a production line perspective. The rationale for a suite of four methods intended to achieve appropriate performance in terms of scope and sensitivity is presented. Overall, the platform encompasses one stream for the determination of 105 compounds in a run (based on acidic QuEChERS-like), plus two streams for 23 β-lactams (alkaline QuEChERS-like) and 10 tetracyclines (low-temperature partitioning), respectively, and a dedicated stream for 14 aminoglycosides (molecularly-imprinted polymer). [ABSTRACT FROM AUTHOR]

The human intestinal microbiome, a generally stable ecosystem, could be potentially altered by the ingestion of antimicrobial drug residues in foods derived from animals. Data and the scientific published literature on the effects of antimicrobial residues on the human intestinal microbiome are reviewed by national regulatory authorities as part of the human food safety evaluation of veterinary antimicrobial agents used in food-producing animals. In this study, we determined if tetracycline, at low residue concentrations, could impact the human intestinal microbiome structure and the resistance-gene profile, following acute and subchronic exposure. The effects of 0.15, 1.5, 15, and 150 μg/ml of tetracycline, after 24 h and 40 days of exposure, in 3% human fecal suspensions, collected from three individuals (A, B, and C) were investigated using in vitro batch cultures. Results were variable, with either no change or minor changes in total bacterial 16S rRNA gene copies after exposure of fecal samples to tetracycline, because of the inter-individual variation of human gastrointestinal tract microbiota. Bacterial community analysis using rRNA-based pyrosequencing revealed that Firmicutes and Bacteroidetes were the predominant phyla in the three fecal samples; the ratio of phylotypes varied among individuals. The evaluation of bacterial community changes at the genus level, from control to tetracycline-treated fecal samples, suggested that tetracycline under the conditions of this study could lead to slight differences in the composition of intestinal microbiota. The genus Bacteroides (of the Bacteroidetes ) was consistently altered from 1.68 to 5.70% and 4.82–8.22% at tetracycline concentrations of 0.15 μg/ml or above at both time points for individual A, respectively, and increased 5.13–13.50% and 10.92–22.18% for individual B, respectively. Clostridium family XI increased 3.50–25.34% in the presence of tetracycline at 40 days for individual C. Principal Component Analysis (PCA) confirmed the pyrosequencing findings of inter-individual variability of the ratio of phylotypes and the effect of tetracycline. Among the 23 tetracycline resistance genes (TRGs) screened, four tet genes ( tetO , Q , W , and X ) were major TRGs in control and tetracycline-dosed fecal samples. A variable to slight increase of copy number of TRGs appeared to be related to tetracycline treatment, interindividual variability and duration of exposure. Despite, the inherent variability of the intestinal microbiota observed among or within individuals, this pilot study contributes to the knowledge base of the impact of low residue concentrations of tetracycline on the human intestinal microbiome on the potential for antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Absorbed doses to human organs from 188 Re-Rituximab in the free form and bound to superparamagnetic iron oxide nanoparticles were predicted from results of the radiopharmaceutical biodistribution studies in mice by the RADAR method. Overall, equivalent and effective doses to human organs from the radiopharmaceutical on the nanoparticles were higher because of the enhanced permeability and retention effect. Liver, spleen and kidneys received higher equivalent doses than other organs (5.29, 3.70 and 3.06 mSv/MBq, respectively, for the free radiopharmaceutical and 6.12, 3.96 and 3.93 mSv/MBq for the drug on the nanoparticles). [ABSTRACT FROM AUTHOR]

Eco-pharmacovigilance (EPV) is a practical and powerful approach to minimize the potential risks posed by pharmaceutical residues in environment. However, it is impracticable to practise rigorous and unitary EPV process for all the existing and new pharmaceuticals. Here, we focused on non-steroidal anti-inflammatory drugs (NSAIDs), and discussed the necessity and potential opportunities of practising EPV of NSAIDs. We found that the consumption of NSAIDs is huge and ubiquitous across the globe. NSAIDs were worldwidely reported as one of the most dominant and frequently detected groups in environmental matrices including wastewater, surface water, suspended solids, sediments, groundwater, even drinking water. Besides, there is definitive evidence for the adverse impacts of NSAID residues on scavenging birds and aquatic species. These data suggested the necessity of implementing EPV of NSAIDs. From the perspective of drug administration, we identified some things that can be done as management practice options for EPV implementation on NSAIDs: ● Improving knowledge and perceptions of pharmacy/health care practitioners about EPV of NSAIDs. ● Emphasizing the control of NSAIDs pollution sources, including preventing unnecessary consumption and unrational use of NSAIDs; promoting the safe disposal of medicines among the general public; controlling the manufacturing-related releases. ● Identifying high-risk areas of NSAIDs pollution and associated risk factors. ● Identifying high priority NSAIDs to be monitored in environment. ● Lifting the world-wide ban on the production and sale of veterinary diclofenac in support of meloxicam, the only NSAID currently considered safe for vultures. ● Designing and constituting a multidisciplinary framework for EPV of NSAIDs. [ABSTRACT FROM AUTHOR]

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) may serve as a new assay for drug testing in a human context, but their validity particularly for the evaluation of inotropic drug effects remains unclear. In this blinded analysis, we compared the effects of 10 indicator compounds with known inotropic effects in electrically stimulated (1.5Hz) hiPSC-CM-derived 3-dimensional engineered heart tissue (EHT) and human atrial trabeculae (hAT). Human EHTs were prepared from iCell hiPSCCM, hAT obtained at routine heart surgery. Mean intra-batch variation coefficient in baseline force measurement was 17% for EHT and 49% for hAT. The PDE-inhibitor milrinone did not affect EHT contraction force, but increased force in hAT. Citalopram (selective serotonin reuptake inhibitor), nifedipine (LTCC-blocker) and lidocaine (Na+ channel-blocker) had negative inotropic effects on EHT and hAT. Formoterol (beta-2 agonist) had positive lusitropic but no inotropic effect in EHT, and positive clinotropic, lusitropic, and inotropic effects in hAT. Tacrolimus (calcineurin-inhibitor) had a negative inotropic effect in EHTs, but no effect in hAT. Digoxin (Na+-K+-ATPase-inhibitor) showed a positive inotropic effect only in EHTs, but no effect in hAT probably due to short incubation time. Ryanodine (ryanodine receptor-inhibitor) reduced contraction force in both models. Rolipram and acetylsalicylic acid showed noninterpretable results in hAT. Contraction amplitude and kinetics were more stable over time and less variable in hiPSC-EHTs than hAT. HiPSC-EHT faithfully detected cAMP-dependent and -independent positive and negative inotropic effects, but limited beta-2 adrenergic or PDE3 effects, compatible with an immature CM phenotype. [ABSTRACT FROM AUTHOR]

Albendazole, one of the benzimidazole anthelmintics, is used in ruminants and has maximum residue limits in muscle, fat and other tissue owing to reported teratogenicity. Albendazole is extensively metabolised in domestic animals and humans with rapid conversion to a sulphoxide and subsequently sulphone and amino sulphone metabolites. Sulphoxide metabolites are responsible for the systemic biological activity of benzimidazole drugs. Herein we report a case of disputed results for albendazole in a consignment sampled at import in which the Official Analyst certified against the consignment for excess albendazole. A laboratory acting for the importer reported data below the MRL, including a finding of the parent drug which is not included in the residue definition. The Government Chemist has a statutory duty as a route of technical appeal in the UK Official Food Control system and the case was referred for referee analysis. We report our findings based on a LC-MS/MS method, which confirmed the official findings, did not reveal the presence of the parent drug but identified hot spots of albendazole marker residues in the consignment. We discuss the need for recommendations on official sampling at import and interpretation of results. [ABSTRACT FROM PUBLISHER]

Montelukast, a leukotriene receptor antagonist commonly prescribed for treatment of asthma, is primarily metabolized by cytochrome P450 (CYP)2C8, and has been suggested as a probe substrate for investigating CYP2C8 activity in vivo. We evaluated the quantitative role of hepatic uptake transport in its pharmacokinetics and drug-drug interactions (DDIs). Montelukast was characterized with significant active uptake in human hepatocytes, and showed affinity towards organic anion transporting polypeptides (OATPs) in transfected cell systems. Single-dose rifampicin, an OATP inhibitor, decreased montelukast clearance in rats and monkeys. Clinical DDIs of montelukast were evaluated using physiologically based pharmacokinetic modeling; and simulation of the interactions with gemfibrozil-CYP2C8 and OATP1B1/1B3 inhibitor, clarithromycin-CYP3A and OATP1B1/1B3 inhibitor, and itraconazole-CYP3A inhibitor, implicated OATPs-CYP2C8-CYP2C8 interplay as the primary determinant of montelukast pharmacokinetics. In conclusion, hepatic uptake plays a key role in the pharmacokinetics of montelukast, which should be taken into account when interpreting clinical interactions. [ABSTRACT FROM AUTHOR]

A novel method coupling molecular imprinted monolithic column with two-dimensional liquid chromatography was developed and validated for the analysis of clenbuterol in pork liver and swine urine samples. The polymers were characterized by using Fourier transform infrared spectroscopy, nitrogen adsorption desorption analyses, frontal analysis and the adsorption of selectivity. The results indicated that the imprinted columns were well prepared and possessed high selectivity adsorption capacity. Subsequently, the MIMC-2D-LC (molecular imprinted monolithic column-two dimensional liquid chromatography) method was developed for the selective analysis of clenbuterol in practical samples. The accuracy ranged from 94.3% to 99.7% and from 93.7% to 99.6% for liver and urine, respectively. The relative standard deviation (RSD) of repeatability was lower than 8.6% for both analyses. The limit of detections was 16 ng·mL −1 for liver and 25 ng·mL −1 for urine, respectively. Compared with the reported methods, the disturbance of endogenous impurity could be avoided by the 2D-LC method. [ABSTRACT FROM AUTHOR]

The manufacture of methamphetamine in clandestine drug laboratories occurs in various locations, including residential houses and apartments. Unlike the controlled manufacture of chemicals and drugs, clandestine manufacture results in the uncontrolled storage, use, generation, and disposal of a wide range of chemicals and the deposit of methamphetamine drug residues on indoor surfaces (1). These residues have been found at high levels on porous and nonporous surfaces and have been shown to persist for months to years (1). Persons exposed to these environments often have poorly defined exposures and health effects. It is commonly assumed that these levels of exposure are low compared with those related to illicit drug use or therapeutic use of amphetamine-based drugs for managing behavioral issues such as attention deficit hyperactivity disorder (2). In 2015, a family that was unknowingly exposed to methamphetamine residues in a house in Australia was found to have adverse health effects and elevated methamphetamine levels in hair samples, highlighting the potential for public health risks for persons who might live in methamphetamine-contaminated dwellings. This case study highlights the importance of the identification and effective decontamination of former clandestine drug laboratories. [ABSTRACT FROM AUTHOR]

Background Intrathecal lidocaine hydrochloride under general anesthesia has been used as an alternative method of euthanasia in equids. Carnivore, scavenger, and even human consumption of horse meat from carcasses have been anecdotally reported in rural areas after this method of euthanasia. The presence of drug residues in horse meat has not been investigated. Hypothesis/Objectives To investigate if drug residues are found in horse tissues and determine their concentrations. Animals Of 11 horses requiring euthanasia for medical reasons. Methods Prospective descriptive study. Horses were anesthetized with total IV dose of xylazine (mean, 2.5 mg/kg), midazolam (0.1 mg/kg), and ketamine hydrochloride (mean, 5.8 mg/kg). An atlanto-occipital cisterna centesis for the collection of cerebrospinal fluid ( CSF) and administration of lidocaine hydrochloride (4 mg/kg) was performed. Blood samples for both serum and plasma, skeletal muscle ( triceps brachii, gluteus medius), and CSF were collected for the determination of drug residues. Frozen skeletal muscle available from 5 additional horses that received standard dosages of drugs for short-term anesthesia (xylazine 1.1 mg/kg, midazolam 0.1 mg/kg, and ketamine 2.2 mg/kg) also were analyzed. Results Drug residues were found in the tissues of all horses, but at extremely low concentrations. Conclusions and Clinical Importance Euthanasia by administration of lidocaine intrathecally to horses under IV anesthesia poses a low risk of toxicity to carnivores and scavengers that might consume muscle tissue from a carcass in which this protocol has been used. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial resistance (AMR) adversely impacts the prevention and treatment of a wide range of infections and is considered as a serious threat to global public health. Occupational-related AMR is a neglected area of research.Objective: To assess exposure to penicillin dust, penicillin active materials, and to report the frequency of penicillin resistance among pharmaceutical workers in Tehran, Iran.Methods: A quasi-experimental study was conducted among workers on a penicillin production line in a pharmaceutical company (n = 60) and workers in a food producing company (n = 60). Data were collected via survey, air sampling, and throat swab.Results: The mean overall concentrations of penicillin dust and penicillin active material were 6.6 and 4.3 mg/m3, respectively, in the pharmaceutical industry. Streptococcus pneumoniae (S. pneumoniae) was detected in 45% (27) individuals in the exposed group, 92.6% of which showed penicillin resistance. Resistance was significantly higher among workers in penicillin production line (p = 0.014).Conclusions: High level of AMR among workers in penicillin production line is a health risk for the workers as well as society as a whole through the spread of drug resistant micro-organisms. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effect of post-resistance exercise alcohol ingestion on lipopolysaccharide (LPS)-stimulated production of IFNγ, TNF-α, IL-1β, IL-6, IL-8, and IL-10.Methods: Recreationally resistance-trained men (n = 10, 25 ± 3 year, 177 ± 7 cm, 83.8 ± 15.7 kg, 14.8 ± 8.5% body fat) and women (n = 8, 23 ± 2 year, 161 ± 3 cm, 59.5 ± 6.0 kg, 26.5 ± 3.0% body fat) completed two identical heavy back squat sessions (6 × 10 at 80% 1 repetition maximum) followed by ingestion of either an alcohol (ALC; 1.09 g ethanol · kg fat-free mass(-1)) or water (PLA) drink. Blood samples were collected before exercise (PRE), and at 3 h (3 h), and 5 h (5 h) after exercise, stimulated with LPS, and analyzed for IFNγ, TNF-α, IL-1β, IL-6, IL-8, and IL-10 concentrations.Results: There were no drink conditions by time effects for IFNγ, TNF-α, IL-1β, or IL-10. Regardless of condition, resistance exercise induce an increase in IFNγ, TNF-α, and IL-1β at 5 h compared to PRE but a decrease in IL-10 at 3 and 5 h compared to PRE. For ALC, IL-8 was reduced at 5 h compared to PLA. From PRE to 3 h, IL-6 was reduced for ALC but increased for PLA; resistance exercise induced an increase in IL-6 for both conditions at 5 h.Conclusions: Heavy resistance exercise increased production of IFNγ, TNF-α, IL-1β, and Il-6 and decreased production of IL-10. Alcohol ingestion after resistance exercise affected aspects of inflammatory capacity (IL-6 and IL-8 production). It appears that some of the effects previously observed for alcohol ingestion alone on the LPS-stimulated cytokine production were overwhelmed by the response to resistance exercise. [ABSTRACT FROM AUTHOR]

Xylazine as veterinary medicine for sedation, but intoxication cases in humans were identified in the last few years. A highly sensitive method is required for analyzing xylazine and its metabolites in human blood and urine. This article presents an ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UHPLC-QTOF) study for simultaneous determination of xylazine and 2,6-dimethylaniline (DMA) in human blood and urine. The samples were extracted and cleaned up by Oasis MCX solid-phase extraction. The analysis is performed using an UHPLC-QTOF. Analysis precision, accuracy, sensitivity, linear range, limit of detection (LOD) and limit of quantification (LOQ) were validated for the proposed method. In the blood and urine samples, the linear calibration curves with high linearity are obtained over the range of 2.0-1,000.0 ng/mL. The LOD for xylazine and DMA in blood are 0.2 and 0.1 ng/mL, in urine are 0.4 and 0.2 ng/mL; the LOQ for xylazine and DMA in blood are 0.6 and 0.3 ng/mL, in urine are 1.0 and 0.6 ng/mL, respectively. The intra- and interday precision is better than 8.6 and 11.9%. In conclusion, the proposed method is highly sensitive and reproducible, thus suitable for accurate quantification of xylazine and its metabolites in blood and urine. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the deposition and depletion process of clenbuterol (CL) in goat tissues, plasma and urine after the repeated administration of a growth-promoting dose. The experiment was conducted in 24 goats (21 treated and 3 controls). Treated animals were administered orally in a dose of 16 µg/kg body mass once daily for 21 consecutive days and randomly sacrificed on days 0.25, 1, 3, 7, 14, 21 and 28 of the withdrawal period. CL in goat tissues was extracted with organic solvents and determined using liquid chromatography tandem mass spectrometry. The depletion rates of tissue differed significantly. The highest concentrations of CL in all tissues are detected on day 0.25 of treatment discontinuation. After administration had been discontinued for 28 days, CL still residues in all tissues, especially, in whole eye, where the concentrations reach 363.29 ± 31.60 µg/kg. These findings confirmed that the whole eye, which are rich in pigment, showed a much higher concentration than any other studied tissue during the withdrawal period. [ABSTRACT FROM AUTHOR]

The author offers information on analysis of veterinary drug residue in food, biological and environmental matrices. Topics discussed include use of screening analyses to test antimicrobial drug residues performed using microbiological inhibitor tests such as Enzyme-linked immunosorbent assay (ELISA), use of liquid chromatography-mass spectrometry (LC-MS) for residue analysis in food and feed, and evolution of anti-doping analysis from urine samples analysis using radioimmunoassays (RIA).

Human flavin-containing monooxygenase 3 (hFMO3), a membrane-bound hepatic protein, belonging to the second most important class of phase-1 drug-metabolizing enzymes, was immobilized in its active form on graphene oxide (GO) for enhanced electrochemical response. To improve protein stabilization and to ensure the electrocatalytic activity of the immobilized enzyme, didodecyldimethylammonium bromide (DDAB) was used to mimic lipid layers of biological membranes and acted as an interface between GO nanomaterial and the hFMO3 biocomponent. Grazing angle attenuated total reflectance Fourier transform infrared (GATR-FT-ER) experiments confirmed the preservation of the protein secondary structure and fold. Electrochemical characterization of the immobilized enzyme with GO and DDAB on glassy carbon electrodes was carried out by cyclic voltammetry, where several parameters including redox potential, electron transfer rate, and surface coverage were determined. This system's biotechnological application in drug screening was successfully demonstrated by the N-oxidation of two therapeutic drugs, benzydamine (nonsteroidal anti-inflammatory) and tamoxifen (antiestrogenic widely used in breast cancer therapy and chemoprevention), by the immobilized enzyme. [ABSTRACT FROM AUTHOR]

Gemcitabine (difluorodeoxycytidine; dFdCyd) is a potent radiosensitizer, noted for its ability to enhance cytotoxicity with radiation at noncytotoxic concentrations in vitro and subchemotherapeutic doses in patients. Radiosensitization in human tumor cells requires dFdCyd-mediated accumulation of cells in S phase with inhibition of ribonucleotide reductase, resulting in ≥80% deoxyadenosine triphosphate (dATP) depletion and errors of replication in DNA. Less is known of the role of specific DNA replication and repair pathways in the radiosensitization mechanism. Here the role of homologous recombination (HR) in relationship to the metabolic and cell cycle effects of dFdCyd was investigated using a matched pair of CHO cell lines that are either proficient (AA8 cells) or deficient (irs1SF cells) in HR based on expression of the HR protein XRCC3. The results demonstrated that the characteristics of radiosensitization in the rodent AA8 cells differed significantly from those in human tumor cells. In the AA8 cells, radiosensitization was achieved only under short (≤4 h) cytotoxic incubations, and S-phase accumulation did not appear to be required for radiosensitization. In contrast, human tumor cell lines were radiosensitized using noncytotoxic concentrations of dFdCyd and required early S-phase accumulation. Studies of the metabolic effects of dFdCyd demonstrated low dFdCyd concentrations did not deplete dATP by ≥80% in AA8 and irs1SF cells. However, at higher concentrations of dFdCyd, failure to radiosensitize the HR-deficient irs1SF cells could not be explained by a lack of dATP depletion or lack of S-phase accumulation. Thus, these parameters did not correspond to dFdCyd radiosensitization in the CHO cells. To evaluate directly the role of HR in radiosensitization, XRCC3 expression was suppressed in the AA8 cells with a lentiviral-delivered shRNA. Partial XRCC3 suppression significantly decreased radiosensitization [radiation enhancement ratio (RER) = 1.6 ± 0.15], compared to nontransduced (RER = 2.7 ± 0.27; P = 0.012), and a substantial decrease compared to nonspecific shRNA-transduced (RER = 2.5 ± 0.42; P = 0.056) AA8 cells. Although the results support a role for HR in radiosensitization with dFdCyd in CHO cells, the differences in the underlying metabolic and cell cycle characteristics suggest that dFdCyd radiosensitization in the nontumor-derived CHO cells is mechanistically distinct from that in human tumor cells. [ABSTRACT FROM AUTHOR]

The characterization of site-specific microheterogeneity in glycoprotein is very important for understanding cell biology and disease processes. Vitronectin is well known to be a multifunctional glycoprotein in the blood and the extracellular matrix, which is related to hepatocellular carcinoma (HCC). Here, we systematically analyzed the site-specific N-glycopeptides of vitronectin in human plasma by tandem mass spectrometry combined with immunoprecipitation and hydrophilic interaction liquid chromatography (HILIC) enrichment. Vitronectin was purified with immunoprecipitation by monoclonal antibody from plasma and digested to tryptic N-glycopeptides.Then, enrichment with HILIC materials was used and followed by analysis with nano-LC/MS/MS. The sequences of N-glycopeptides were identified from the mass spectra by high-energy C-trap dissociation (HCD) and collision-induced dissociation (CID). In HCD mode, oxonium ions were used for recognizing glycopeptides and y ions for sequencing the peptide backbone. In CID mode, Y ions were used for characterizing their glycoforms. As a result, a total of 17 site-specific N-glycopeptides were completely identified in all of the three N-glycosylation sites of vitronectin in human plasma, including 12 N-glycopeptides first reported. Finally, we specifically found that three hybrid and four complex glycopeptides of triantennary forms with outer fucosylation increased in HCC human plasma. [ABSTRACT FROM AUTHOR]

A rapid and sensitive method for the screening and selective quantification of antibiotics in urine by two-dimensional ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was developed. This method allowed the injection of 200 μL urine extract. The 200-μL injection volume used in this method increased the absolute sensitivity for target antibiotics in solvent by an average 13.3 times, with a range from 8.4 to 28.5 times, compared with the 10-μL conventional injection volume. A 96-well solid phase extraction procedure was established to eliminate the contamination on the chromatographic column resulting from the large-volume injection and increase the throughput of sample preparation. Fourteen target antibiotics from six common categories (β-lactams, quinolones, tetracyclines, macrolides, sulfonamides, and chloramphenicols) were selected as model compounds, and a database containing an additional 74 antibiotics was compiled for posttarget screening. The limit of detection of the target antibiotics, defined as a signal-to-noise ratio of 3, ranged from 0.04 to 1.99 ng/mL. The mean interday recoveries ranged between 79.6 and 121.3 %, with a relative standard deviation from 2.9 to 18.3 % at three spiking levels of 20 ng/mL, 50 ng/mL, and 100 ng/mL. This method was successfully applied in 60 real urine samples from schoolchildren aged 8-11 years, and four target antibiotics (azithromycin, sulfadiazine, trimethoprim, and oxytetracycline) and two posttarget antibiotics (sulfadimidine and cefaclor) were found in the urine samples. This method can be used as a large-scale biomonitoring tool for exposure of the human population to antibiotics. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A microfluidic chip containing stamped antibody arrays was developed for simultaneous cell separation and drug testing. Poly(dimethyl siloxane) (PDMS) stamping was used to deposit antibodies in a microfluidic channel, forming discrete cell-capture regions on the surface. Cell mixtures were then introduced, resulting in the separation of cells when specific antibodies were used. Anti-CD19 antibody regions resulted in 94 % capture purity for CD19+ Ramos cells. An antibody that captures multiple cell types, for example anti-CD71, can also be used to capture several cell types simultaneously. Cells could also be loaded onto the arrays with spatial control using laminar streams. Both Ramos B cells and HuT 78 T cells were isolated in the chip and exposed to staurosporine in the same channel. Both cell lines had similar responses to the drug, with 2-10 % of cells remaining viable after 20 h of drug treatment, depending on cell type. The chip can also be used to analyze the efficacy of antibody therapy against cancer cells. Anti-CD95 was deposited on the surface and used for simultaneous cell capture and apoptosis induction via the extrinsic pathway. Cells captured on anti-CD95 surfaces had significant viability loss (15 % viability after 24 h) when compared with a control anti-CD71 antibody (81 % viability after 24 h). This chip can be used for a variety of cell separation and/or drug testing studies, enabling researchers to isolate cells and test them against different anti-cancer compounds and to follow cell response using fluorescence or other readout methods. [ABSTRACT FROM AUTHOR]

Fluoroquinolones (FQNs) are broad-spectrum antibacterial agents widely used in animal husbandry and aquaculture. The residues and antimicrobial resistance of such antibiotics are a major public health concern. To realize multianalyte detection of FQN residues, a genetically modified bacterium, Escherichia coli pK12 harboring plasmid pRecAlux3, was constructed in this study to develop a bioluminescent-bacteria-based assay for the detection of FQNs in animal-derived foods. This assay was based on the principle of induction of an SOS response by FQNs via inducing the recA-promoter-fused luciferase reporter gene existing on the plasmid pRecAlux3. E. coli pK12 was able to recognize 11 FQNs: difloxacin, enrofloxacin, ciprofloxacin, sarafloxacin, norfloxacin, danofloxacin, ofloxacin, pefloxacin, lomefloxacin, marbofloxacin, and orbifloxacin. This method could be applied to 11 edible tissues, including milk, fish muscle, and the muscles, livers, and kidneys of cattle, chickens, and pigs, with a very simple and rapid sample extraction procedure using only phosphate-buffered saline. The limits of detection of the FQNs were between 12.5 and 100 μg kg, all of which were lower than the maximum residue limits. Most of the recoveries of the FQNs were in the range from 60 to 120 %, and the interassay coefficients of variation were less than 30 %. This method, confirmed by high-performance liquid chromatography, is reliable and can be used as both a screening test and a semiquantitative assay, when the identity of a single type of FQN is known. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This paper reports the development of a method based on high-performance liquid chromatography (HPLC) coupled to second-order data modeling with multivariate curve resolution-alternating least-squares (MCR-ALS) for quantification of retinoic acid and its main isomers in plasma in only 5.5 min. The compounds retinoic acid (RA), 13- cis-retinoic acid, 9- cis-retinoic acid, and 9,13-di- cis-retinoic acid were partially separated by use of a Poroshell 120 EC-C18 (3.0 mm × 30 mm, 2.7 μm particle size) column. Overlapping not only among the target analytes but also with the plasma interferents was resolved by exploiting the second-order advantage of the multi-way calibration. A validation study led to the following results: trueness with recoveries of 98.5-105.9 % for RA, 95.7-110.1 % for 13- cis-RA, 97.1-110.8 % for 9- cis-RA, and 99.5-110.9 % for 9,13-di- cis-RA; repeatability with RSD of 3.5-3.1 % for RA, 3.5-1.5 % for 13- cis-RA, 4.6-2.7 % for 9- cis-RA, and 5.2-2.7 % for 9,13-di- cis-RA (low and high levels); and intermediate precision (inter-day precision) with RSD of 3.8-3.0 % for RA, 2.9-2.4 % for 13- cis-RA, 3.6-3.2 % for 9,13-di- cis-RA, and 3.2-2.9 % for 9- cis-RA (low and high levels). In addition, a robustness study revealed the method was suitable for monitoring patients with dermatological diseases treated with pharmaceutical products containing RA and 13- cis-RA. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Objectives Recent clinical data have suggested high raltegravir concentrations in gut tissue after oral administration, with implications for treatment and prevention. We have used in silico, in vitro, ex vivo and in vivo models to further investigate the accumulation of raltegravir in gut tissue. Methods Affinity of raltegravir for gut tissue was assessed in silico (Poulin–Theil method), in vitro (Caco-2 accumulation) and ex vivo (rat intestine) and compared with the lipophilic drug lopinavir. Finally, raltegravir concentrations in plasma, gut contents, small intestine and large intestine were determined after oral dosing to Wistar rats 1 and 4 h post-dose. Samples were analysed using LC-MS/MS and scintillation counting. Results Gut tissue accumulation of raltegravir was less than for lopinavir in silico, in vitro and ex vivo (P < 0.05). After oral administration to rats, raltegravir concentrations 4 h post-dose were lower in plasma (0.05 μM) compared with small intestine (0.47 μM, P = 0.06) and large intestine (1.36 μM, P < 0.05). However, raltegravir concentrations in the contents of both small intestine (4.0 μM) and large intestine (40.6 μM) were also high. Conclusions In silico, in vitro and ex vivo data suggest low raltegravir accumulation in intestinal tissue. In contrast, in vivo animal data suggest raltegravir concentrates in intestinal tissue even when plasma concentrations are minimal. However, high raltegravir concentrations in gut contents are the likely driving factor behind this observation, rather than blood-to-tissue drug distribution. The methods described can be combined with clinical investigations to provide a complete strategy for selection of drugs with high gut accumulation. [ABSTRACT FROM PUBLISHER]

Cancer metastasis and drug resistance are important malignant tumor phenotypes that cause roughly 90% mortality in human cancers. Current therapeutic strategies, however, face substantial challenges partially due to a lack of applicable pre-clinical models and drug-screening platforms. Notably, microscale and three-dimensional (3D) tissue culture platforms capable of mimicking in vivo microenvironments to replicate physiological conditions have become vital tools in a wide range of cellular and clinical studies. Here, we present a microfluidic device capable of mimicking a configurable tumor microenvironment to study in vivo-like cancer cell migration as well as screening of inhibitors on both parental tumors and migratory cells. In addition, a novel evaporation-based paper pump was demonstrated to achieve adaptable and sustainable concentration gradients for up to 6 days in this model. This straightforward modeling approach allows for fast patterning of a wide variety of cell types in 3D and may be further integrated into biological assays. We also demonstrated cell migration from tumor spheroids induced by an epidermal growth factor (EGF) gradient and exhibited lowered expression of an epithelial marker (EpCAM) compared with parental cells, indicative of partial epithelial-mesenchymal transition (EMT) in this process. Importantly, pseudopodia protrusions from the migratory cells – critical during cancer metastasis – were demonstrated. Insights gained from this work offer new opportunities to achieve active control of in vitro tumor microenvironments on-demand, and may be amenable towards tailored clinical applications. [ABSTRACT FROM AUTHOR]

Abstract: This pilot study sought to test the feasibility of procedures to screen students for marijuana use in Student Health Services (SHS) and test the efficacy of a web-based intervention designed to reduce marijuana use and consequences. Students were asked to participate in voluntary screening of health behaviors upon arrival at SHS. One hundred and twenty-three students who used marijuana at least monthly completed assessments and were randomized to one of four intervention conditions in a 2 (intervention: Marijuana eCHECKUP TO GO vs. control)×2 (site of intervention: on-site vs. off-site) between-groups design. Follow-up assessments were conducted online at 3 and 6months. Latent growth modeling was used to provide effect size estimates for the influence of intervention on outcomes. One thousand and eighty undergraduate students completed screening. The intervention did not influence marijuana use frequency. However, there was evidence of a small overall intervention effect on marijuana-related consequences and a medium effect in stratified analyses in the on-site condition. Analyses of psychological variables showed that the intervention significantly reduced perceived norms regarding peer marijuana use. These findings demonstrate that it is feasible to identify marijuana users in SHS and deliver an automated web-based intervention to these students in different contexts. Effect size estimates suggest that the intervention has some promise as a means of correcting misperceptions of marijuana use norms and reducing marijuana-related consequences. Future work should test the efficacy of this intervention in a full scale randomized controlled trial. [Copyright &y& Elsevier]

Rationale: Many older adults report sleep problems and use of hypnotics. Several studies have shown that hypnotics can have acute adverse effects on driving the next morning. It is unclear however whether driving of chronic hypnotic users is impaired. Therapeutic effects on insomnia and development of tolerance may reduce the residual effects on driving. Objectives: The present study aimed to compare actual driving performance and driving-related skills of chronic hypnotic users to good sleepers. To determine whether insomnia itself affects driving performance, driving and driving-related skills were compared between insomnia patients who do not or infrequently use hypnotics and good sleepers. Methods: Twenty-two frequent users of hypnotics (using hypnotics ≥4 nights per week for more than 3 months), 20 infrequent users (using hypnotics ≤3 nights per week), and 21 healthy, age-matched controls participated in this study. On the night before testing, all subjects were hospitalized for an 8-h sleep recorded by polysomnography. Frequent hypnotic users used their regular medication at bedtime (2330 hours), while infrequent users and controls received no medication. Cognitive performance (word learning, digit span, tracking, divided attention, vigilance, and inhibitory control) was assessed 8.5 h and driving performance between 10 and 11 h after bedtime and dosing. Results: Polysomnographic recordings did not significantly differ between the groups, but the insomnia patients, treated or untreated, still reported subjective sleep complaints. Results show no differences in driving performance and driving-related skills between both groups of insomnia patients and controls. Conclusions: Driving performance in chronic users of hypnotics and untreated insomnia patients is not impaired. For chronic users, this may be due to prescription of relatively safe drugs and low doses. For untreated insomniacs, this corroborates previous findings showing an absence of neuropsychological deficits in this group of patients. [ABSTRACT FROM AUTHOR]

Rationale: Residual effects of hypnotics on driving performance have been mainly determined in studies using a standardized driving test with healthy good sleepers. Responses to effects may differ, however, between insomniacs and healthy volunteers due to the underlying sleep disorder. In addition, a majority of insomniacs uses hypnotics chronically resulting in the development of tolerance to impairing effects. Impaired driving performance in healthy volunteers may then be an overestimation of the actual effects in insomniacs. Objectives: The present study aims to compare the residual effects of zopiclone 7.5 mg on on-the-road driving performance of 16 middle-aged insomniacs chronically using hypnotics (chronic users), 16 middle-aged insomniacs not or infrequently using hypnotics (infrequent users), and 16 healthy, age matched, good sleepers (controls). Methods: The study was conducted according to a 3 × 2 double-blind, placebo controlled crossover design, with three groups and two treatment conditions. Treatments were single oral doses of zopiclone 7.5 mg and placebo administered at bedtime (2330 hours). Between 10 and 11 h after administration subjects performed a standardized highway driving test. Results: Zopiclone 7.5 mg significantly impaired on-the-road driving performance in both insomnia groups and healthy controls. The magnitude of impairment was significantly less in the chronic users group as compared with the controls. Conclusions: The smaller magnitude of effects suggests that investigating residual effects of hypnotics in healthy volunteers may yield a minor overestimation of the actual effects in insomnia patients. [ABSTRACT FROM AUTHOR]

A single-laboratory validation (SLV) study was conducted on an LC/MS/MS method for the determination and confirmation of nicarbazin, expressed as 4,4-dinitrocarbanilide (DNC), in chicken tissues, including liver, kidney, muscle, skin with adhering fat, and eggs. Linearity was demonstrated with DNC standard curve solutions using a weighted (1/x) regression and confirmed with matrix-matched standards. Intertrial repeatability precision (relative standard deviation of repeatability; RSDr) was from 2.5 to 11.3%, as determined in fortified tissues. The precision was verified with incurred tissue, and varied from 0.53 to 2.5%. Average recoveries ranged from 82% in egg to 98% in kidney. Although the average recoveries across all concentrations were within the acceptable range, the method was improved with the inclusion of an internal standard and the use of matrix-matched standards. Accuracy for the improved method in chicken liver varied from 93 to 99% across all concentrations (100-8000 ng/g) compared to recoveries below 80% at concentrations between 100-400 ng/g in chicken liver for the original method. The limit of detection was estimated to be less than 3.0 ng/g in all tissue types, and the limit of quantitation was validated at 20 ng/g. Based on confirmatory ion ratios and peak retention times, the false-negative rate was estimated as 0.00% (95% confidence limits 0.00, 0.74%) from 484 fortified samples and 12 incurred residue samples analyzed using the U.S. and EU confirmation criteria. Small variations to the method parameters, with the exception of injection volume, did not have a significant effect on recoveries. Stability was determined for fortified tissues, extracts, and standard curve solutions. The data collected in this study satisfy the requirements of SLV studies established by the AOAC Stakeholder Panel for Veterinary Drug Residue and the method was awarded First Action Official MethodSM status by the Expert Review Panel for Veterinary Drug Residues on May 7, 2013. [ABSTRACT FROM AUTHOR]

Study Objective This study was designed to prospectively evaluate the in vivo activities of drug transporters, metabolizing enzymes, and pharmacokinetics in patients with chronic kidney diseases ( CKD) caused by glomerulonephritis and nonglomerular etiologies. Design A prospective study design. Participants Eighteen adults with CKD. Setting General Clinical Research Center at the University of North Carolina and University of Pittsburgh. Measurement and Main Results Blood and urine were collected and assayed for fexofenadine (transporter function) as well as flurbiprofen and 4-hydroxyflurbiprofen ( CYP2C9 function). CYP3A4 activity was assessed by the erythromycin breath test. In patients with glomerulonephritis, the apparent oral clearance of fexofenadine (representing transporter activity) was 58.8 ± 34.4 L/hour, documenting a 40% reduction compared with previous data in healthy controls. The CYP2C9 pathway (4-hydroxyflurbiprofen formation clearance) was similar in all the patients with CKD and was concordant with previous reports of patients with end-stage renal disease ( ESRD) and healthy controls. For flurbiprofen, patients with glomerulonephritis had higher oral clearance than those with nonglomerular CKD, suggesting higher unbound fraction and enhanced metabolism through other (non- CYP2C9) routes. No statistically significant differences in CYP3A4 activity were observed in either group of patients or when compared with results from previous studies of patients with ESRD or healthy controls. Conclusions The current study suggests no statistically significant differences in the in vivo activity of CYP2C9 and CYP3A4 in patients with either glomerulonephritis or nonglomerular CKD. However, there are clinical differences in transporter function as defined by at least a 25% reduction in activity in glomerulonephritis as opposed to healthy controls. A similarity in the in vivo function between patients with glomerulonephritis and ESRD, and between patients with glomerulonephritis and nonglomerular CKD was present despite significant differences in kidney function. Further in vivo and in vitro studies are necessary to fully understand the physiologic and disease-specific nuances that contribute to alterations in drug disposition in patients with kidney diseases. [ABSTRACT FROM AUTHOR]

The suitability of different receptor-binding assays to detect antibiotics in raw goat's milk was investigated. Detection capability of most β-lactams and tetracyclines assessed applying the Betastar Combo, the SNAP Betalactam, the SNAP Tetracycline, and the Twinsensor tests was at or below maximum residue limits established by European legislation. Regarding test specificity, cross-reactions with antibiotics other than β-lactams and tetracyclines were not found, and no false-positive results were obtained for the Betastar Combo and the SNAP tests when bulk samples of goat's milk were analyzed. For the Twinsensor test, the false-positive rate was 1%. The performance of the Betastar Combo and the SNAP tests was practically unaffected by the milk quality parameters using individual samples of goat's milk collected at points throughout the entire lactation period (false-positive rate, ≤5%). However, a larger number of positive results were obtained by the Twinsensor test in this type of milk sample (> 10%), especially in the last weeks of lactation. Interferences related to the use of the preservative azidiol were not observed in any case. Neither were any significant differences found in relation to the interpretation method (visual versus instrumental) applied. In general, the response of the Betastar Combo, SNAP, and Twinsensor tests was optimal for the analysis of bulk caprine milk; thus, they may be used to monitor milk for the presence of β-lactam and tetracycline residues in quality control programs. [ABSTRACT FROM AUTHOR]

A simple, cow-side test for the presence of drug residues in live animal fluids would provide useful information for tissue drug residue avoidance programs. This work describes adaptation and evaluation of rapid screening tests to detect drug residues in serum and urine. Medicated heifers had urine, serum, and tissue biopsy samples taken while on drug treatment. Samples were tested by rapid methods and high-performance liquid chromatography (HPLC). The adapted microbial inhibition method, kidney inhibition swab test, was useful in detecting sulfadimethoxine in serum, and its response correlated with the prescribed withdrawal time for the drug, 5 to 6 days posttreatment. The lateral flow screening method for flunixin and beta-lactams, adapted for urine, was useful in predicting flunixin in liver detected by HPLC, 96 h posttreatment. The same adapted methods were not useful to detect ceftiofur in serum or urine due to a lack of sensitivity at the levels of interest. These antemortem screening test studies demonstrated that the method selected, and the sampling matrix chosen (urine or serum), will depend on the drug used and should be based on animal treatment history if available. The live animal tests demonstrated the potential for verification that an individual animal is free of drug residues before sale for human consumption. [ABSTRACT FROM AUTHOR]

A quantitative multi-class analytical method covering more than 226 veterinary drugs and other contaminants in muscle, belonging to different drug families, was developed. The method is based on liquid–liquid extraction, purification by low-temperature clean-up and dispersive solid-phase extraction (D-SPE), and analysis was conducted in two analytical runs by column-switching UPLC coupled with electrospray ionisation and tandem mass spectrometry (UPLC-ESI-MS/MS). For most of the target analytes, the optimised pre-treatment processes led to no significant interference from the sample matrix. The limit of quantification varied from 0.05 to 10 µg kg–1. Statistical evaluation indicated that average recoveries spiked into pork were in the range from 62.4% to 138.8%, and the relative standard deviations were in the range from 2.8% to 26.6% (intra-day precision). The availability of this method will contribute to a better safety assurance of meat with a significant reduction of both effort and time. [ABSTRACT FROM AUTHOR]

Decomposed bone and plasma samples of rats exposed to amitriptyline (AMI) and Citalopram (CiT) under different dosing patterns were analyzed. Wistar rats received one acute dose (120 mg AMI/kg and 40 mg CIT/kg; n = 5) or two doses (40 mg AMI/kg and 13 mg CIT/ kg, n = 5) 40 min apart. After collection of perimortem blood, the rats were euthanized and placed outdoors to decompose to skeleton. Recovered bone was ground and subjected to methanolic extraction. Bone extracts and plasma samples underwent solid-phase extraction and were analyzed using ultra-high-performance liquid chromatography. Concentrations of drugs and the primary metabolites [nortriptyline (N0RT), desmethylcitalopram (DMCIT) and didesmethylcitalopram (DDMCIT)] were expressed as mass-normalized response ratios (RR/m). Concentrations (RR/m) of AMI, CIT and metabolites did not differ significantly between exposure types in plasma and all bone types examined or for the pooled bone samples [P > 0.05). However, ratios of concentrations of N0RT to those of AMI differed significantly between exposure patterns for all bone types except for rib (P < 0.05). Values of DMCIT/CIT differed significantly between exposure patterns in rib, pelvi and femora (P < 0.05). Values of DDMCIT/CIT did not differ significantly between exposure types (P > 0.05), while those of DDMCIT/DMCIT were significantly different for all bones except the vertebrae and rib (P < 0.05). [ABSTRACT FROM AUTHOR]

Sample preparation methods with high temporal resolution and matrix resistance will benefit fast direct analysis of analytes in a complex matrix, such as drug monitoring in biofluids. In this work, the core-sheath biocompatible electrospun nanofiber was fabricated as a micro-solid phase extraction material. With the poly(N-isopropylacrylamide) (PNIPAAm) as sheath polymer and polystyrene (PS) as core polymer, the fiber membrane was highly hydrophilic and exhibited good antifouling ability to proteins and cells. Its complete expansion in aqueous solution and its nanoscale fiber (100-200 nm) structure offered high mass transfer rate of analytes between liquid and solid phases. The equilibration time of microextraction with this membrane was all shorter than 2 min for eight drugs tested, and the linear ranges covered more than 3 orders of magnitude for most of them. This membrane could be applied to monitor free drugs in plasma and their protein binding kinetics by equilibrium-microextraction with a 2 min temporal resolution. The results showed that the core-sheath electrospun nanofiber membrane would be a better alternative of solid phase material for microextraction with good matrix-resistance ability and high temporal resolution. [ABSTRACT FROM AUTHOR]

German Environment Specimen Bank (GESB) fish tissue samples, collected from 14 different GESB locations, were analyzed for 15 pharmaceuticals, 2 pharmaceutical metabolites, and 12 personal care products. Only 2 pharmaceuticals, diphenhydramine and desmethylsertraline, were measured above MDL. Diphenhydramine (0.04-0.07 ng g-1 ww) and desmethylsertraline (1.65-3.28 ng g-1 ww) were measured at 4 and 2 locations, respectively. The maximum concentrations of galaxolide (HHCB) (447 ng g-1 ww) and tonalide (AHTN) (15 ng g-1 ww) were measured at the Rehlingen sampling site in the Saar River. A significant decrease in HHCB and AHTN fish tissue concentrations was observed from 1995 to 2008 at select GESB sampling sites (r2 = 0.69-0.89 for galaxolide and 0.89-0.97 for tonalide with p < 0.003). Galaxolide and tonalide fish tissue concentrations in Germany were 19x and 28x lower, respectively, as compared to fish tissue concentrations measured in a United States nationwide PPCP study conducted in 2006. Proximity of the sampling locations to the upstream wastewater treatment plant discharging point and mean annual flow at the sampling location were found to significantly predict galaxolide and tonalide fish tissue concentrations (HHCB: r2 = 0.79, p = 0.021 and AHTN: r2 = 0.81, p = 0.037) in Germany. [ABSTRACT FROM AUTHOR]

The effect of 17β-19-nortestosterone (17βNT) treatment of barrows on residue levels and growth was evaluated. Five barrows were treated three times during the fattening period with 17βNT phenylpropionate (Nandrosol, nandrolone phenylpropionate 50 mg/ml,1 mg/kg body weight). Another five barrows were untreated and five boars (untreated) were kept as positive control. Boars and treated barrows showed a 13 and 9% improvement in growth compared to untreated barrows, with mean final body weights of 121.6, 117.8 and 109.0 kg, respectively. The bulbourethral glands of the treated barrows were three times heavier than untreated barrows. The histology of the prostate and bulbourethral gland of the treated barrows was comparable to the boars, whereas the control barrows showed atrophic glands. Levels of 17βNT ester in hair from treated barrows were high, whereas boars and untreated barrows did not show levels above LLQ. It is concluded that analysis of hair can detect illegal treatment with 17βNT ester in barrows. The size of the bulbourethral gland can also be used for screening in the slaughterhouse. [ABSTRACT FROM PUBLISHER]

Abstract: This study assessed the applicability of a Bacillus stearothermophilus test for detection of the depletion of furazolidone anticoccidial drug residues in chicken tissues. Thirty-three Ross breed chicken were dosed orally with furazolidone (2mg/kg body weight) daily for 5 days. After the last treatment the birds were sacrificed in groups of three at intervals of 1, 3, 6, 10, 24, 48, 144, 240, 360 and 480h. Liver, kidney and breast muscle samples were collected and immediately analysed at each interval for furazolidone residues. Serum was separated from the blood collected from jugular veins into bottles containing glass beads and analysed. Supernatant from the homogenates was analysed for the presence or absence of furazolidone residues using the B. stearothermophilus test. Semi quantification of furazolidone residues was done by comparing the obtained zones of inhibition on a Bacillus subtilis test plates and the zones from calibrated standard curves. Qualitatively the B. stearothermophilus test was positive for furazolidone residues up to 480h post treatment in serum samples, 360h in liver samples, 480h in kidney samples and 360h in muscle samples. Semi quantitatively from the B. subtilis test plates, serum samples were observed to have the highest furazolidone concentration of 3.2μg/ml. The lowest furazolidone concentration was recorded in kidney tissues at 0.21μg/ml. Kidney and serum tissues appear to be good tissues for testing of furazolidone tissues. The Kidney samples would appear best for post-mortem screening of furazolidone residues while serum could be used antemortem screening of depletion in chicken. [Copyright &y& Elsevier]

We assessed ampicillin (ABPC) concentrations of kidney, muscle and intestine after a 5-day withdrawal period in 2 male and a female young Large White pigs fed the diet containing ABPC (ABPC medicated feed, 24 mg/kg/day) for a week. The ABPC residues were measured with liquid chromatography-tandem mass spectrometry, and the mean recoveries and quantitation limits ranged from 91.8 to 97.2% and from 0.1 to 0.12 ng/g, respectively. The residual ABPC concentrations were ≤1.18 ng/g for the muscle, ≤0.53 ng/g for the kidney and ≤1.93 ng/g for the intestine, suggesting below the Japanese provisional maximum residue limits. These results reveal that the analytical method is developed for residual ABPC and that the withdrawal period is appropriate. [ABSTRACT FROM AUTHOR]

Saliva is an excellent analytical matrix for the detection of illicit drug residues such as tetrahydrocannabinol and amphetamine. Analysis of drugs in saliva offers significant advantages compared to blood or urine. These include ease of sample collection, reduced sample processing and greater accessibility for collection. However to fully exploit its potential knowledge of the physiology and of saliva, salivary drug metabolism, optimal collection strategies, rapid, sensitive and specific assays and possible interferences is required. The method selected for sample collection can also have a significant impact on the validity of the testing method. This review critically analyses these factors, the current approaches used and potential future developments in salivary drug analysis. [ABSTRACT FROM AUTHOR]

Abstract: The pharmacokinetics and active metabolite of enrofloxacin were estimated after single intramuscular administration (10.0 or 20.0 mg/kg body weight) to the Chinese mitten-handed crab (Eriocheir sinensis) in fresh water at 25.0±1.0 °C. Levels of enrofloxacin and its metabolite ciprofloxacin in the main tissues (hemolymph, hepatopancreas, muscle, ovary and spermary) were simultaneously detected by HPLC. Enrofloxacin concentration–time profiles for the hemolymph in both tests were described by a two-compartment open model with first-order absorption. Distribution half-time (T 1/2α ), elimination half-time (T 1/2β ), body clearance (CL/F), mean residence time (MRT0–∞), area under the concentration–time curve from 0 to ∞h (AUC0–∞) and apparent volume of distribution (Vd/F), which derived from the pharmacokinetic model, were 0.427 h, 21.3 h, 0.133 l/h/kg, 60.0 h, 96.9 μg/ml/h and 4.08 l/kg, respectively, at a dose of 10.0 mg/kg body weight, and 0.216 h, 12.3 h, 0.189 l/h/kg, 85.8 h, 187 μg/ml/h and 3.35 l/kg, respectively, at a dose of 20.0 mg/kg body weight. Similarities were found between the hemolymph concentration–time curves of the two tests; for example, instant absorption process followed by the distribution phrase, and a second absorption peak at 6 h post-treatment. After intramuscular administration of 10.0 mg/kg body weight, absorption of enrofloxacin was observed in the main edible tissues (hepatopancreas, muscle, ovary and spermary), and the drug residue was the highest in the hepatopancreas, where the ‘drug sink’ phenomenon occurred. Comparative pharmacokinetics showed fast absorption, broad distribution and fast elimination of enrofloxacin in E. sinensis after intramuscular dosing. Regarding ciprofloxacin, the main active metabolite of enrofloxacin, though relatively low levels were detected in all the main tissues of the crab, its kinetics in the hemolymph in the two tests were not described by a one- or two-compartment open model. [Copyright &y& Elsevier]