Trace analysis of progesterone and 21 progestins in milk by ultra-performance liquid chromatography coupled with high-field quadrupole-orbitrap high-resolution mass spectrometry.

A method for rapid screening and quantification of progesterone and progestins in milks by ultrahigh-performance liquid chromatography coupled with quadrupole-high field Orbitrap high-resolution mass spectrometry (UHPLC QE HF HRMS) was established. Milks samples were extracted by acetonitrile + hexane (80 + 20), purified by prime HLB SPE and analyzed by UHPLC QE HF HRMS. The detection limit of progesterone and 21 progestins in milk is between 0.05 µg/kg -0.3 µg /kg, the correlation coefficient of progesterone and progestins in the corresponding concentration range is more than 0.99, recoveries for milk samples are between 80.7% and 108.3% with the relative deviation is less than 15%.The method fulfils the requirements of veterinary drug residue detection validation of EU and China, and successfully applied to detecting the µg/kg level of progesterone and monitoring residual of progestins in real milk.

Sensitive and Fast Determination of Ceftiofur in Honey and Veterinary Formulation by HPLC-UV Method with Pre-column Derivatization.

A novel, sensitive and rapid high performance liquid chromatography (HPLC) method for the determination of ceftiofur by pre-column derivatization with 1,2-naphthoquinone-4-sulfonate. Analysis was performed within 5 min on a Kinetex C18 column based on core-shell technology. The mobile phase composed of acetonitrile-water (50:50, v/v) pumped isocratically at a flow rate of 1.0 mL/min under UV detection at 254 nm. The factors affecting the derivatization reaction and separation conditions were carefully evaluated and optimized. The method was linear over the concentration range of 45-450 ng/mL with a limit of detection of 3.29 ng/mL and limit of quantitation of 10.97 ng/mL. The new method was successfully applied for the analysis of ceftiofur in the veterinary formulation and honey with average recoveries of 100.78% and 98. 83%, respectively. The present method is suitable and favorable for the analysis of ceftiofur on account of its sensitivity, rapidity and cost-effectiveness. In addition, it could have significant application for the determination of ceftiofur in other food products.

Perspectives of photodynamic therapy in biotechnology.

Photodynamic therapy (PDT) is a current and innovative technique that can be applied in different areas, such as medical, biotechnological, veterinary, among others, both for the treatment of different pathologies, as well as for diagnosis. It is based on the action of light to activate photosensitizers that will perform their activity on target tissues, presenting high sensitivity and less adverse effects. Therefore, knowing that biotechnology aims to use processes to develop products aimed at improving the quality of life of human and the environment, and optimizing therapeutic actions, researchers have been used PDT as a tool of choice. This review aims to identify the impacts and perspectives and challenges of PDT in different areas of biotechnology, such as health and agriculture and oncology. Our search demonstrated that PDT has an important impact around oncology, minimizing the adverse effects and resistance to chemotherapeutic to the current treatments available for cancer. Veterinary medicine is another area with continuous interest in this therapy, since studies have shown promising results for the treatment of different animal pathologies such as Bovine mastitis, Malassezia, cutaneous hemangiosarcoma, among others. In agriculture, PDT has been used, for example, to remove traces of antibiotics of milk. The challenges, in general, of PDT in the field of biotechnology are mainly the development of effective and non-toxic or less toxic photosensitizers for humans, animals and plants. We believe that there is a current and future potential for PDT in different fields of biotechnology due to the existing demand.

Effects of veterinary antibiotics on the fate and persistence of 17ß-estradiol in swine manure.

The fate and persistence of natural estrogens from livestock manure and the interactions of these compounds with veterinary antibiotics (VAs) have not been well studied. We therefore employed 14C-labeling to explore the mineralization, degradation, and residual distribution of 17ß-estradiol (E2) in swine manure in the absence and presence of six categories of VAs at concentrations of 10 and 100 mg/kg. After 16 days of incubation, 94% of the E2 dissipated, of which 28% was mineralized to 14CO2, 18% was transformed into organic-extractable E1 (9%) and other unknown metabolites (9%), and 48% into non-extractable residues (NER). VAs inhibited, enhanced or had no effect on E2 mineralization or its degradation to E1 and other metabolites. Principal component analysis showed that the overall effect of VAs was not necessarily related to their physicochemical properties or concentrations. However, high doses of macrolides inhibited E2 mineralization in manure and increased the retention of E2 and its metabolites in both free and NER forms. Our study demonstrates that considerable amounts of E2 and NER are retained in manure, despite nearly complete mineralization. Thus, VAs administered to livestock may increase the persistence of natural estrogens in manure and, accordingly, the environmental risks posed by these compounds.

Computational Assessment of Pharmacokinetics and Biological Effects of Some Anabolic and Androgen Steroids.

PURPOSE: The aim of this study is to use computational approaches to predict the ADME-Tox profiles, pharmacokinetics, molecular targets, biological activity spectra and side/toxic effects of 31 anabolic and androgen steroids in humans. METHODS: The following computational tools are used: (i) FAFDrugs4, SwissADME and admetSARfor obtaining the ADME-Tox profiles and for predicting pharmacokinetics;(ii) SwissTargetPrediction and PASS online for predicting the molecular targets and biological activities; (iii) PASS online, Toxtree, admetSAR and Endocrine Disruptomefor envisaging the specific toxicities; (iv) SwissDock to assess the interactions of investigated steroids with cytochromes involved in drugs metabolism. RESULTS: Investigated steroids usually reveal a high gastrointestinal absorption and a good oral bioavailability, may inhibit someof the human cytochromes involved in the metabolism of xenobiotics (CYP2C9 being the most affected) and reflect a good capacity for skin penetration. There are predicted numerous side effects of investigated steroids in humans: genotoxic carcinogenicity, hepatotoxicity, cardiovascular, hematotoxic and genitourinary effects, dermal irritations, endocrine disruption and reproductive dysfunction. CONCLUSIONS: These results are important to be known as an occupational exposure to anabolic and androgenic steroids at workplaces may occur and because there also is a deliberate human exposure to steroids for their performance enhancement and anti-aging properties.

Study of praziquantel phytoremediation and transformation and its removal in constructed wetland.

Accumulation and/or degradation of Praziquantel (PZQ) in plants were determined using Phragmites australis, both suspension cultures and in vitro cultivated plants. In case of initial PZQ concentration 20mgL-1, 90% was removed from liquid media within 21days. The accumulated PZQ was partly metabolized, twenty one compounds being identified, products of both Phase I and II of detoxification metabolism. Laboratory results were confirmed in real scale using the constructed wetland (CW), where PZQ (500mg in total) was completely removed until the first purification pond. This result offers a promising possibility to use CW for PZQ removal from agricultural as well as domestic waste-waters.

Veterinary antibiotics used in animal agriculture as NDMA precursors.

The formation of carcinogenic N-nitrosodimethylamine (NDMA) during chloramination at drinking water treatment plants has raised concerns as more plants have switched from chlorine to chloramine disinfection. In this study, a source of NDMA precursors that has yet to be investigated was examined. Veterinary antibiotics are used in large quantities at animal agricultural operations. They may contaminate drinking water sources and may not be removed during wastewater and drinking water treatment. Ten antibiotics used in animal agriculture were shown to produce NDMA or N-nitrosodiethylamine (NDEA) during chloramination. Molar conversions ranged from 0.04 to 4.9 percent, with antibiotics containing more than one dimethylamine (DMA) functional group forming significantly more NDMA. The highest formation for most of the compounds was seen near pH 8.4, in a range of pH 6 to 11 that was investigated. The effect of chlorine-to-ammonia ratio (Cl2/NH3), temperature, and hold time varied for each chemical, suggesting that the effects of these parameters were compound-specific.

Health concerns and management of select veterinary drug residues.

The aim of this manuscript is to review the potential adverse health effects in humans if exposed to residues of selected veterinary drugs used in food-producing animals. Our other objectives are to briefly inform the reader of why many of these drugs are or were approved for use in livestock production and how drug residues can be mitigated for these drugs. The selected drugs include several antimicrobials, beta agonists, and phenylbutazone. The antimicrobials continue to be of regulatory concern not only because of their acute adverse effects but also because their use as growth promoters have been linked to antimicrobial resistance. Furthermore, nitroimidazoles and arsenicals are no longer approved for use in food animals in most jurisdictions. In recent years, the risk assessment and risk management of beta agonists, have been the focus of national and international agencies and this manuscript attempts to review the pharmacology of these drugs and regulatory challenges. Several of the drugs selected for this review can cause noncancer effects (e.g., penicillins) and others are potential carcinogens (e.g., nitroimidazoles). This review also focuses on how regulatory and independent organizations manage the risk of these veterinary drugs based on data from human health risk assessments.

Immobilization of tetracyclines in manure and manure-amended soils using aluminum-based drinking water treatment residuals.

Veterinary antibiotics (VAs) are emerging contaminants of concern in the environment, mainly due to the potential for development of antibiotic-resistant bacteria and effect on microbiota that could interfere with crucial ecosystem functions such as nutrient cycling and decomposition. High levels of VAs such as tetracyclines (TCs) have been reported in agricultural soils amended with manure, which also has the potential to cause surface and groundwater contamination. Several recent studies have focused on developing methods to immobilize VAs such as composting with straw, hardwood chips, commercial biochar, aeration, mixing, heat treatment, etc. The major shortcomings of these methods include high cost and limited effectiveness. In the current study, we assessed the effectiveness of aluminum-based drinking water treatment residuals (Al-WTR) as a "green" sorbent to immobilize TCs in manure and manure-applied soils with varying physicochemical properties by laboratory incubation study. Results show that Al-WTR is very effective in immobilizing tetracycline (TTC) and oxytetracycline (OTC). The presence of phosphate resulted in significant (p < 0.01) decrease in TTC/OTC sorption by Al-WTR, but the presence of sulfate did not. attenuated total reflection (ATR)-FTIR spectroscopy indicate that TTC and OTC likely forming surface complexes via inner-sphere-type bonds in soils, manure, and manure-applied soils amended with Al-WTR.

Development of a multi-residue method for fast screening and confirmation of 20 prohibited veterinary drugs in feedstuffs by liquid chromatography tandem mass spectrometry.

A simple multiresidue method was developed for detecting and quantifying twenty analytes from 5 classes of prohibited veterinary drugs (ß-agonists (9), anabolic hormones (4), quinoxalines (4), tranquilizers (1), cyproheptadine, and clonidine in animal feeds using a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach. Feed samples were extracted by ultrasonic-assisted extraction with a mixture of methanol-acetonitrile (50:50, v/v), followed by a cleanup using a dispersive solid-phase extraction with PSA (primary secondary amine). Target compounds were separated and determined by a liquid chromatography tandem quadrupole mass spectrometer operating in positive electrospray ionization mode, using multiple reaction monitoring (MRM). The recoveries of these compounds were between 56.7% and 103% at three spiked levels. The repeatability was lower than 10%, whereas reproducibility was no more than 15% except for nandrolone (17% at 10µgkg(-1)) and diazepam (19% at 10µgkg(-1)). Decision limits (CCαs) and detection capabilities (CCßs) ranged from 0.42 to 5.74µgkg(-1) and 5.70-9.81µgkg(-1), respectively. The method was successfully applied to screening of real samples obtained from local feed markets and confirmation of the suspected target analytes.

Immune-mediated agranulocytosis caused by the cocaine adulterant levamisole: a case for reactive metabolite(s) involvement.

The United States Public Health Service Administration is alerting medical professionals that a substantial percentage of cocaine imported into the United States is adulterated with levamisole, a veterinary pharmaceutical that can cause blood cell disorders such as severe neutropenia and agranulocytosis. Levamisole was previously approved in combination with fluorouracil for the treatment of colon cancer; however, the drug was withdrawn from the U.S. market in 2000 because of the frequent occurrence of agranulocytosis. The detection of autoantibodies such as antithrombin (lupus anticoagulant) and an increased risk of agranulocytosis in patients carrying the human leukocyte antigen B27 genotype suggest that toxicity is immune-mediated. In this perspective, we provide an historical account of the levamisole/cocaine story as it first surfaced in 2008, including a succinct review of levamisole pharmacology, pharmacokinetics, and preclinical/clinical evidence for levamisole-induced agranulocytosis. Based on the available information on levamisole metabolism in humans, we propose that reactive metabolite formation is the rate-limiting step in the etiology of agranulocytosis associated with levamisole, in a manner similar to other drugs (e.g., propylthiouracil, methimazole, captopril, etc.) associated with blood dyscrasias. Finally, considering the toxicity associated with levamisole, we propose that the 2,3,5,6-tetrahydroimidazo[2,1-b]thiazole scaffold found in levamisole be categorized as a new structural alert, which is to be avoided in drug design.

Correlations between no observed effect level and selected parameters of the chemical structure for veterinary drugs.

No observed effect level (NOEL) represents the lowest value among numerous parameters used for the analysis of risk and the safety of a chemical substance and medicinal product. In the present study, the correlation between NOEL and selected topological parameters was determined for a group of 135 veterinary drugs. Due to the high values of the standard deviation for most of the parameters, the method of NOEL mean values analysis in quintile groups was used. The direct correlations between NOEL and the partition coefficient octanol/water (LogKOW), logarithm of water solubility value (LogSw), polar surface area (PSA), apolar surface area (aPSA), hydrogen bond acceptors and hydrogen bond donors were very low. In quintile groups a significant correlation (P<0.05) between NOEL and LogKOW, aPSA, PSA, as well as between NOEL and equations based on topological parameters were found. The results obtained indicate that, among the analysed parameters, LogSw and PSA play a crucial role in relation to a drug activity, at the NOEL level, in the tested group of compounds. Moreover, the calculation tools, based on the analysis of the molecular structure of topological parameters, can be useful for the prognosis of parameters describing drug safety.

Bioavailability of veterinary drugs in vivo and in silico.

The physical and chemical properties of a drug determine the behaviour of its molecule in a living organism. In this paper, the relationship between selected physical and chemical parameters and drug bioavailability in vivo was investigated. Data sets from 75 compounds, which can be administered per os to 11 various animal species were analyzed. The selected parameters for the prediction of the in vivo bioavailability were the lipophilicity (LogP) and the polar surface area (PSA) or apolar surface area (aPSA) of a molecule. It was shown that the calculation of the hybrid parameters aPSA/PSA and LogP + (aPSA/PSA) allows to estimate the oral bioavailability of a drug and its allocation to clusters with either an oral bioavailability of <70% or >70%. The performed analysis also showed that an extreme low value of the PSA of a molecule (<40 square ångströms) combined with the extreme high value of LogP (>4) is associated with a lower oral bioavailability (<50%). The results obtained indicate the existence of a relationship between the mean LogP value and aPSA/PSA in silico, and the bioavailability of veterinary drugs as determined in vivo.

Solid-phase extraction and gas chromatographic- mass spectrometric determination of the veterinary drug xylazine in human blood.

This paper presents a method for the determination of xylazine in whole blood using solid-phase extraction and gas chromatography-mass spectrometry. This technique required only 0.5 mL of sample, and protriptyline was used as internal standard (IS). Limits of detection and quantitation (LOQ) were 2 and 10 ng/mL, respectively. The method was found to be linear between the LOQ and 3.50 microg/mL, with correlation coefficients higher than 0.9922. Precision (intra- and interday) and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The analyte was stable in the matrix for at least 18 h at room temperature and for at least three freeze/thaw cycles. Mean recovery, calculated at three concentration levels, was 87%. To the best of our knowledge, this is the first time that solid-phase extraction is used as sample preparation technique for the determination of this compound in biological media. Because of its simplicity and speed when compared to other extraction techniques, the herein described method can be successfully applied in the diagnosis of intoxications by xylazine.