Publications by authors named "Weilin L Shelver"

Micro/nanoplastics (MP/NP) are pervasive contaminants that are detected throughout the environment in diverse matrices. Exposure to MP/NP have been demonstrated in humans by their presence in numerous body fluids and tissues. Due to the large quantity of production and broad applications, polymethyl methacrylate (PMMA) MP/NP have frequently been measured in surveys of microplastics in the environment.

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Microplastics have become a ubiquitous contaminant, but their fate in food animals is largely unknown. In this study, [C]-polystyrene microplastic (PS-MP) particles were orally dosed to lactating sheep to evaluate their absorption and disposition. Elimination of the [C]-PS-MP was predominately through faeces with faecal radioactivity peaking at 24 h post-dosing but continuing to be present throughout the entire 72 h study period.

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The accurate detection of ractopamine in food animals is crucial for marketing since some entities require animals or animal carcasses to be free of ractopamine residues. Field-based ractopamine screening tests that are rapid, sensitive, and capable of high-throughput are highly desirable to ensure that inadvertent exposure to ractopamine did not occur in animals marketed as animals that have not been fed ractopamine. An immunochemically based lateral flow assay was used to analyze oral fluids from hogs never exposed to ractopamine and from hogs that were presumed positives and results were confirmed using an enhanced sensitivity LC-MSMS method.

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Micro/nanoplastics (MP) are emerging environmental contaminants of great concern because of their ubiquitous distribution in air, soil, water, and food. Reports have described MP in the excreta of food animals, but their absorption, distribution, and elimination in terrestrial animals used for human consumption is essentially unexplored. To determine the absorption and distribution of [C]-polystyrene (PS) MP, laying hens (n = 15) were bolus dosed with 10 μCi/hen (11.

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Micro/nanoplastics (MP/NP) contaminate our food and drinking water but their impact on human health has not been well-documented. The liver is one of the first organs that ingested MP/NP encounter and it has a major role in the clearance of xenobiotics. Therefore, the effects of polystyrene MP/NP on liver HepG2 cells were studied.

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Background: Triclosan, bisphenol A (BPA), and brominated flame retardants are environmental estrogenic endocrine-disrupting compounds that may influence the prognosis of breast cancer. We examined the urinary concentrations of these compounds and their associations with demographic characteristics and body fatness in a population of women with newly diagnosed breast cancer. Methods: Overnight urine collection and anthropometric measures were obtained from 302 participants.

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Toxicity of micro or nanoplastics (MP/NP) in aquatic life is well-documented, however, information about the consequences of exposure to these particles in terrestrial species is scarce. This study was used to evaluate the uptake and/or toxicity of polystyrene MP/NP in human gastric cells, comparing doses, particle sizes (50, 100, 200, 500, 1000 or 5000 nm) and surface functionalization (aminated, carboxylated or non-functionalized). In general, the uptake of 50 nm particles was significantly higher than 1000 nm particles.

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Antemortem bodily fluids can serve as an indicator of veterinary medicine exposure prior to food animal slaughter. A multi-residue, rapid screen electrospray ionisation mass spectrometric (RS-ESI-MS) method was developed to analyse 10 veterinary drugs or metabolites (clenbuterol, erythromycin, flunixin, 5-hydroxyflunixin, meloxicam, ractopamine, ractopamine-glucuronide, salbutamol, tylosin, and zilpaterol) in hog oral fluid and bovine urine. Simple acetonitrile extraction with salting-out was employed to remove the analytes from matrices in less than 30 minutes.

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Abstract: Plastics provide tremendous societal benefits and are an indispensable part of our lives. However, fragmented plastics or those intentionally manufactured in small sizes (microplastics and nanoplastics) are of concern because they can infiltrate soils and enter the human food chain through trophic transfer. The pathophysiological impacts of micro- and nanoplastics in humans are not characterized, but their effects in terrestrial mammals may help elucidate their potential effects in humans.

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A 7-plex immunoassay capable of detecting cashew, egg, hazelnut, milk, peanut, shrimp, and soy allergens was used to screen meals ready-to-eat (MREs) and frozen meals that contained meat or poultry. The same food matrices were also evaluated using single individual allergen immunoassays. Multiplex and single allergen test results were compared with the allergen declared on the food label, which was considered the standard.

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This study demonstrates the utility of electrospray ionization inlet mass spectrometry (ESII-MS/MS) for the quantitative determination of analytes in complex animal matrices without chromatographic separation. Veterinary drugs including flunixin, its metabolite 5-hydroxyflunixin, and zilpaterol and persistent organic perfluoroalkyl compounds were determined in incurred plasma, urine, and/or tissue samples. Limits of detection (LOD) of zilpaterol in kidney, liver, lung, and muscle ranged from 0.

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Plastic based products are ubiquitous due to their tremendous utility in our daily lives. However, the limited biodegradable nature of plastics has recently raised pollution concerns globally, especially micro- and nanoplastics. These anthropogenic pollutants are either manufactured specifically in the small size range for various commercial applications or formed due to fragmentation of macro plastics in the environment.

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Rationale: Electrospray ionization mass spectrometry (ESI-MS) in conjunction with liquid chromatography (LC) can provide accurate quantitative data, but it is not well-suited for the rapid screening (RS) of analytes incurred into complex matrices. This study was designed to determine the usefulness of ESI for rapid detection and quantitation of veterinary drugs from complex biological matrices under near real-time conditions.

Methods: Nine veterinary drugs or metabolites, clenbuterol, erythromycin, flunixin, 5-hydroxyflunixin, meloxicam, ractopamine, salbutamol, tylosin and zilpaterol, present in cow urine, sheep urine, sheep tissues (kidney, muscle, liver and lung) or pig kidney, were simultaneously analyzed.

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The study objectives were to estimate plasma flunixin (FLU) pharmacokinetic parameters and milk depletion profiles for FLU and its metabolite (5-hydroxy flunixin; 5-OH) after subcutaneous (SC) and intravenous (IV) administration of single and multiple flunixin meglumine (FM) doses to non-lactating (nulliparous and pregnant does) and lactating dairy goats. Analytical methods (ELISA and UPLC-MS/MS) for quantifying plasma FLU concentrations were compared. The final objective was to use regulatory (FDA and EMA) methods to estimate milk withdrawal intervals following extra-label drug use in goats.

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The distribution of 12 environmental contaminants or metabolites with diverse polarities (2,2',4,4',5-pentabromodiphenyl ether; bisphenol A; estrone; glyphosate; β-hexabromocyclododecane; imidacloprid; 2,3',4,4',5-pentachlorobiphenyl; 3'-methylsulfone 2,2',4,5,5'-pentachlorobiphenyl; 1,2,7,8-tetrachlorodibenzo--dioxin; 2-hydroxy-1,3,7,8-tetrachlorodibenzo--dioxin; tetrabromobisphenol A; and triclocarban) among skim milk, fat, curd, whey, whey retentate, and whey permeate was characterized. Analysis of these compounds along with 15 drugs previously studied provided a robust linear model predicting the distribution between skim and fat and the chemical's lipophilicity (log , = 0.71; log , = 0.

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Study objectives were to determine zilpaterol residues in urine and tissues of sheep fed dietary zilpaterol HCl, at levels commensurate with feed contamination, using common and novel screening and quantitative analytical methods. Sheep (50.0 ± 2.

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A total of 1040 pork kidneys were purchased from 4 retail stores located in a Midwestern US town and screened for antibiotics with the Charm-KIS™ screening test. Six samples (0.6%) tested positive with the Charm-KIS™.

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Ambient ionization mass spectrometric methods including desorption electrospray ionization (DESI) and atmospheric solid analysis probe (ASAP) have great potential for applications requiring real-time screening of target molecules in complex matrixes. Such techniques can also rapidly produce repeatable semiquantitative data, with minimal sample preparation, relative to liquid chromatography-mass spectrometry (LC-MS). In this study, a commercial ASAP probe was used to conduct both ASAP-MS and modified DESI (MDESI) MS analyses.

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The development of a fluorescent multiplexed microarray platform able to detect and quantify a wide variety of pollutants in seawater is reported. The microarray platform has been manufactured by spotting 6 different bioconjugate competitors and it uses a cocktail of 6 monoclonal or polyclonal antibodies raised against important families of chemical pollutants such as triazine biocide (i.e.

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Zilpaterol is a β-adrenergic agonist feed additive approved in the United States to increase weight gain and improve feed efficiency of cattle. A zilpaterol immunochromatographic assay was developed as an economical and user-friendly rapid detection method for zilpaterol and validated using urine and tissue samples derived from animal studies. The assay sensitivity was 1.

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The distributions of eight drugs (acetaminophen, acetylsalicylic acid/salicylic acid, ciprofloxacin, clarithromycin, flunixin, phenylbutazone, praziquantel, and thiamphenicol) were determined in milk products (skim milk, milk fat, curd, whey, and whey protein) and used to expand a previous model (from 7 drugs to 15 drugs) for predicting drug distribution. Phenylbutazone and praziquantel were found to distribute with the lipid and curd phases (≥50%). Flunixin distribution was lower but similar in direction (12% in milk fat, 39% in curd).

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A sample preparation method was evaluated for the determination of polybrominated diphenyl ethers (PBDEs) in mussel samples, by using colorimetric and electrochemical immunoassay-based screening methods. Herein, a rapid procedure based on QuEChERS-like extraction approach followed by solid phase purification was optimized for PBDE extraction from mussel samples. The detection limits for colorimetric and electrochemical immunoassays, calculated as BDE-47 equivalent concentration, were 0.

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Sows (n = 126) were administered penicillin G; urine, collected at slaughter, was screened by kidney inhibition swab (KIS; 4 h testing time) and then stored at -80 °C (∼1200 days) until analysis by lateral flow assay (LF, ∼5 min testing time) and tandem quadrupole LC-MS/MS (TQ) analysis. The stability of penicillin in urine during storage was verified using TQ analyses. Quantitative results were well-correlated (R = 0.

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It is important to understand the partitioning of drugs in processed milk and milk products, when drugs are present in raw milk, in order to estimate the potential consumer exposure. Radioisotopically labeled erythromycin, ivermectin, ketoprofen, oxytetracycline, penicillin G, sulfadimethoxine, and thiabendazole were used to evaluate the distribution of animal drugs among rennet curd, whey, and protein fractions from skim cow milk. Our previous work reported the distribution of these same drugs between skim and fat fractions of milk.

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Twenty dairy cows received flunixin meglumine at 2.2 mg/kg bw, administered once daily by either the intravenous (IV) or intramuscular (IM) route for three consecutive days with either intravenous normal saline (NS) or lipopolysaccharide (LPS) providing a balanced design with five animals per group. Cows were sacrificed after a 4 day withdrawal period, and 13 muscle types were collected and assayed for flunixin by LC-MS/MS.

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