Publications by authors named "Gregory Doran"

Article Synopsis
  • Sarcoptic mange is a serious disease affecting wild bare-nosed wombats, leading to severe skin issues and potential death if untreated.
  • In Australia, moxidectin is approved as a treatment, but there is limited documented evidence of its effectiveness.
  • A case report described two male wombats treated with moxidectin, showing significant improvement in their skin condition and complete clearance of the mites after the treatment.
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Sarcoptic mange is a debilitating disease that affects bare-nosed wombats (Vombatus ursinus). One of the drugs currently used for treatment is moxidectin, as it has a relatively high efficacy against endo and ectoparasites and side effects are uncommon in domestic species, thus it is considered a relatively safe drug to use at the recommended doses. Developing further understanding of the pharmacokinetics of moxidectin will aid in developing treatment regimens for sarcoptic mange in wombats.

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Sarcoptic mange in wombats results from a skin infestation by Sarcoptes mites and if untreated, results in a slow and painful death. Moxidectin is a pesticide used to treat internal and external parasites in cattle, but has shown to effectively treat other animals, including wombats. Two methods were developed to analyse wombat plasma, and methods were also developed to analyse faeces and fur.

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Polycyclic aromatic hydrocarbons (PAHs) are persistent organic compounds of major concern that mainly accumulate in soils and sediments, and their extraction from environmental matrices remains a crucial step when determining the extent of contamination in soils and sediments. The objective of the present study was to compare the extraction of PAHs (phenanthrene, pyrene, chrysene, and benzo[a]pyrene) from spiked soil and sediment using supercritical fluid extraction (SFE) with ethanol as the modifier, microwave-assisted extraction (MAE), and eucalyptus oil-assisted extraction (EuAE). Recoveries of PAHs were comparable between the three methods, and >80% of applied pyrene, chrysene and benzo[a]pyrene were recovered.

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Background: Few methods exist for the analysis of the soil nitrification inhibitor 3,4-dimethyl-1H-pyrazole (3,4-DMP), which is a pesticide with the ability to reduce the production of nitrogenous greenhouse gases in soils as a result of fertilizer application. Due to its small size and polar nature, 3,4-DMP can be difficult to retain on an LC column, which makes diversion of a co-extracted soil matrix away from the MS/MS impossible.

Objective: The current study aims to better control the retention time (RT) of 3,4-DMP.

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The potential for biosurfactant-mediated desorption of polyaromatic hydrocarbons (PAHs) was evaluated using PAH-spiked soil and sediment. PAH desorption behaviors and toxicity of novel saponin biosurfactant extracted from Eucalyptus camaldulensis leaves and sophoro-lipid biosurfactant were investigated. Their PAH desorption efficiencies were compared with rhamnolipid biosurfactant and the industrial-chemical surfactant, Tween 20.

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Whey protein isolate (WPI)-derived bioactive peptide fractions (1−3, 3−5, 5−10, 1−10, and >10 kDa) were for the first time used as emulsifiers in nanoemulsions. The formation and storage stability of WPI bioactive peptide-stabilized nanoemulsions depended on the peptide size, enzyme type, peptide concentration, and storage temperature. The highly bioactive <10 kDa fractions were either poorly surface-active or weak stabilizers in nanoemulsions.

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Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic environmental pollutants that are extremely hydrophobic in nature and resistant to biological degradation. Extraction of PAHs from environmental matrices is the first and most crucial step in PAH quantification. Extraction followed by quantification is essential to understand the extent of contamination prior to the application of remediation approaches.

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Dissipation kinetics of atrazine and trifluralin in a clay loam soil was investigated in a laboratory incubation experiment under different temperature and moisture conditions. The soil was spiked with diluted atrazine and trifluralin concentrations at 4.50 and 4.

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The fraction of any surface-adsorbed contaminant available for absorption is considered the bioaccessible fraction. Applied previously to contaminants such as pesticides and heavy metals on surfaces such as soil, food and cosmetics, the term may also be used to describe the fraction of drug residue bound to work surfaces which may be mobilized via contact transfer with human skin. Police station work surfaces have been shown to commonly contain low levels of drug residues as thin films; however, no information is available on how readily these residues may be transferred to human skin during direct or glancing contact.

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Storage of drug-based evidence inside sealed safes may allow chemical vapors to accumulate, creating concerns of drug exposure by inhalation, or the possibility of cross-contamination of drug evidence. Air samples were taken from inside eight drug safes and one small storage room at nine city and country police stations, as well as a large centralized drug evidence storage vault, in New South Wales (NSW), Australia. Sorbent tubes containing charcoal were used to determine whether any drug residues could be detected in the air, and to identify the types of chemicals present.

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The anaesthetic lidocaine is metabolised quickly to produce a series of metabolites, including several hydroxylated metabolites, which are further metabolised by addition of a glucuronic acid moiety. Analysis of these glucuronide metabolites in urine is performed indirectly by cleaving the glucuronic acid group using β-glucuronidase. However, direct analysis of intact glucuronide conjugates is a more straightforward approach as it negates the need for long hydrolysis incubations, and minimises the oxidation of sensitive hydrolysis products, while also distinguishing between the two forms of hydroxylated metabolites.

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The presence of licit and illicit drug residues on surfaces was studied in 10 police stations and a central drug evidence store in New South Wales, Australia, with the results compared to similar surfaces in four public buildings (to establish a community baseline). The results of almost 850 workplace surface swabs were also compared to the outcome of drug analysis in urine and hair samples volunteered by police officers. Surfaces were swabbed with alcohol and the swabs were extracted and analysed by LC-MS/MS.

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Police officers responsible for the seizure and removal of illegally grown cannabis plants from indoor and outdoor growing operations face the prospect of THC exposure while performing their work duties. As a result, a study investigating the amount of THC on hands and uniforms of officers during raids on cannabis growing houses (CGHs) and forest cannabis plantations (FCPs) and in the air at these sites was conducted. Swabs of gloves/hands, chests, and heads/necks were collected and analysed for THC.

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A normal phase high performance liquid chromatography (HPLC) method was developed to simultaneously quantify several prominent bioactive compounds in canola oil vis. α-tocopherol, γ-tocopherol, δ-tocopherol, β-carotene, lutein, β-sitosterol, campesterol and brassicasterol. The use of sequential diode array detection (DAD) and tandem mass spectrometry (MS/MS) allowed direct injection of oils, diluted in hexane without derivatisation or saponification, greatly reducing sample preparation time, and permitting the quantification of both free sterols and intact sterol esters.

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Removal of the wool-bearing skin around a young lamb's rump (mulesing) provides long term health benefits for the animal, and the use of a sedative and analgesic agent such as xylazine may assist with pain relief to reduce discomfort and stress. Sensitive analytical methods are essential for monitoring pharmaceuticals and their metabolites in animals destined for human consumption. The following work reports a method that is 200 times more sensitive for xylazine detection than previously published methods, with lower limits of quantitation for xylazine and its primary metabolite in animals of 0.

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Objective: To determine the pharmacokinetics of pergolide after IV administration to horses.

Animals: 8 healthy adult horses.

Procedures: Pergolide mesylate was administered IV at a dose of 20 μg/kg (equivalent to 15.

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Pergolide is used to treat pituitary pars intermedia dysfunction (equine Cushing's Disease), a neurodegenerative condition associated with loss of dopaminergic inhibition of the pituitary in horses. After oral administration, only low concentrations of the drug are achieved in plasma, making drug detection and quantification difficult. While direct analysis of plasma using sensitive MS/MS techniques is possible, dirty plasma samples and mobile phase buffers can cause instrumentation to become rapidly incapacitated.

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Heat pre-treated and non heat pre-treated whey protein isolate (WPI) were hydrolysed using α-chymotrypsin (chymotrypsin), pepsin and trypsin. The in vitro antioxidant activity, ACE-inhibition activity and surface hydrophobicities of the hydrolysates were measured in order to determine if peptides with dual functionalities were present. Dual functional peptides have both biological (e.

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The fate of fipronil in flooded, reductive rice soils was modeled using a conceptual model. Rate constants for the various sorption and degradation processes were calculated from experimental studies involving intact soil cores, and the reductive degradation constant was used to calculate half-lives for fipronil on each soil. The data predicted that fipronil was subject to rapid, reductive degradation or immediate sorption to the soil and any sorbed fipronil desorbed was reductively degraded.

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The mobility of the rice pesticides thiobencarb (S-[(4-chlorophenyl) methyl] diethylcarbamothioate) and fipronil ([5-amino-3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]pyrazole) were investigated in the glasshouse under flooded conditions using two Australian rice-growing soils. When using leakage rates of 10 mm day(-1), less than 20% of applied thiobencarb and fipronil remained in the water column after 10 days due to rapid transfer to the soil phase. Up to 70% and 65% of the applied thiobencarb and fipronil, respectively, were recovered from the 0-1 cm layer of soils.

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The impact of oxygen diffusion from plant roots on the soil redox in the root zone in flooded rice bays was investigated using two Australian rice growing soils. The rates of production of Fe(II) and Mn(II) in pore water resulting from the reduction of soil minerals was used to gauge the extent of development of anaerobic conditions and the time taken for equilibrium to establish. Soil concentrations of readily reducible Fe were 13-28 times greater than Mn, making Fe a more reliable indicator of redox conditions than Mn.

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Anaerobic water samples containing levels of soluble Fe(II) may form insoluble Fe(III) particulates that could hinder subsequent extraction and analysis. Solid-phase extraction (SPE) cartridges could become blocked by this material, reducing the volume that can be processed. The ability of ascorbic acid to reduce these Fe(III) colloids and/or to prevent further oxidation of Fe(II) by dissolved oxygen during sampling was investigated and compared to sample stabilization with hydrochloric acid.

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