Significant Turning Point: Common Buzzard (Buteo buteo) Exposure to Second-Generation Anticoagulant Rodenticides in the United Kingdom

Second-generation anticoagulant rodenticides (SGARs) are widely used to control rodent populations, resulting in the serious secondary exposure of predators to these contaminants. In the United Kingdom (UK), professional use and purchase of SGARs were revised in the 2010s. Certain highly toxic SGARs have been authorized since then to be used outdoors around buildings as resistance-breaking chemicals under risk mitigation procedures. However, it is still uncertain whether and how these regulatory changes have influenced the secondary exposure of birds of prey to SGARs. Based on biomonitoring of the UK Common Buzzard (Buteo buteo) collected from 2001 to 2019, we assessed the temporal trend of exposure to SGARs and statistically determined potential turning points. The magnitude of difenacoum decreased over time with a seasonal fluctuation, while the magnitude and prevalence of more toxic brodifacoum, authorized to be used outdoors around buildings after the regulatory changes, increased. The summer of 2016 was statistically identified as a turning point for exposure to brodifacoum and summed SGARs that increased after this point. This time point coincided with the aforementioned regulatory changes. Our findings suggest a possible shift in SGAR use to brodifacoum from difenacoum over the decades, which may pose higher risks of impacts on wildlife.

A facile fluorescence microplate immunoassay based on an in situ fluorogenic reaction for the detection of two highly toxic anticoagulant rodenticides in food and biological matrix

Bromadiolone and brodifacoum, the most frequently used anticoagulant rodenticides, are highly toxic and pose a threat to public health by causing food poisoning incidents. Here, we developed a fluorescence microplate immunoassay for facile and sensitive detection of bromadiolone and brodifacoum by introducing three commercial chemicals (p-phenylenediamine, polyethyleneimine, H2O2) as a new substrate of horseradish peroxidase and then generating fluorescence signals based on an in situ fluorogenic reaction (detection time within 75 min). This assay exhibited higher efficiency in generating fluorescence signals, thereby exhibiting a 6-fold improvement in sensitivity compared with colorimetric ELISA. The limit of detection was 0.23-0.28 ng/mL (ng/g) for bromadiolone and 0.34-0.61 ng/mL (ng/g) for brodifacoum in corn and human serum, with recovery ratios higher than 82.3 %. These satisfactory results illustrated our proposed assay was a potential tool for food analysis and poisoning diagnosis caused by bromadiolone and brodifacoum.

Active monitoring of long-eared owl (Asio otus) nestlings reveals widespread exposure to anticoagulant rodenticides across different agricultural landscapes

The widespread use of anticoagulant rodenticides (ARs) poses a worldwide threat to farmland wildlife. These compounds accumulate in tissues of both target and non-target species, potentially endangering both direct consumers and their predators. However, investigations on ARs in blood of free-ranging predatory birds are rare. Here, the long-eared owl (Asio otus) has been used as a model predator to assess AR exposure in different agricultural landscapes from a Mediterranean semiarid region. A total of 69 owlets from 38 nests were blood-sampled over 2021 and 2022, aiming to detect AR residues and explore factors that determine their exposure, such as land uses. In addition, prothrombin time (PT) test was conducted to assess potential effects of AR contamination. Overall, nearly all the samples (98.6 %) tested positive for at least one compound and multiple ARs were found in most of the individuals (82.6 %). Among the ARs detected, flocoumafen was the most common compound (88.4 % of the samples). AR total concentration (ΣARs) in blood ranged from 0.06 to 34.18 ng mL-1, detecting the highest levels in the most intensively cultivated area. The analysis of owl pellets from 19 breeding territories showed relevant among-site differences in the contribution of rodents and birds into the diet of long-eared owls, supporting its high dietary plasticity and indicating AR presence at multiple trophic levels. Moreover, a positive and significant correlation was found between ΣARs and PT (Rho = 0.547, p < 0.001), which demonstrates the direct effect of ARs on free-living nestlings. Our results provide a preliminary overview of AR exposure in a little-studied owl species inhabiting agricultural and rural landscapes. Despite the low detected levels, these findings indicate widespread exposure -often to multiple compounds- from early life stages, which raises concern and draws attention to an ongoing and unresolved contamination issue.

Exposure assessment of anticoagulant rodenticides in the liver of red foxes (Vulpes vulpes) in Slovenia

The study deals with the environmental residues of anticoagulant rodenticides (ARs) in Slovenia to evaluate the toxicological risk of secondary poisoning of red foxes (Vulpes vulpes) as representatives of non-target wildlife, and in relation to the investigated use patterns of ARs and specific local parameters in Slovenia. From 2019 to 2022, 148 liver tissue samples of adult red foxes were collected from almost all state geographical regions. The samples were extracted with methanol/water (2:1, v/v), cleaned-up using a solid supported liquid-liquid extraction, and measured by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) with reporting limits of 0.5 to 5.0 ng/g. Residues of at least one rodenticide were detected in 77.7 % of the samples. The second generation ARs of bromadiolone, brodifacoum and difenacoum were the most frequently found, appearing in 75.0, 51.4, and 18.9 % of the samples, respectively. Concentrations of pooled ARs ranged from 1.5 to 2866.5 ng/g with mean and median values of 601.4 and 350.2 ng/g, respectively. We determined bromadiolone and brodifacoum at concentrations of ≥800 ng/g in 10.8 and 10.1 % of the samples, and 1.4 and 0.7 % of the samples contained residues >2000 ng/g, respectively. These concentrations are much higher than those found in comparable studies in Europe and elsewhere in the world. Residues of ARs were detected in all monitored statistical regions of Slovenia, with higher concentrations in the eastern parts of the country. First generation ARs were found in only 9.5 % of samples, and residues were below 10 ng/g with one exception (coumatetralyl with 55 ng/g). The results of the study indicate a serious toxicological risk for red foxes in Slovenia as part of the Western Balkans, and will contribute to the growing body of knowledge about the protection of European ecosystems, as wildlife is not limited by national borders.

A rapid and sensitive analytical methodology for the simultaneous biomonitoring of two direct oral anticoagulant drugs and their major metabolites in thromboembolic disordered patients samples for clinical evaluations

Apixaban and dabigatran are the two major direct oral anticoagulant drugs to treat thromboembolic disordered patients. Increasing the clinical application for the thromboembolic disorder and monitoring the concentrations of apixaban, dabigatran, and their metabolites are essential in most clinical circumstances. In this work, we developed a rapid analytical methodology comprising of vortex-assisted salt-enhanced liquid-liquid microextraction technique coupled with UHPLC-MS/MS for the extraction and simultaneous determination of two major direct oral anticoagulant drugs (apixaban, dabigatran), and their two major metabolites from plasma, serum, and urine samples of patients. The developed method was optimized with various procedural steps and validated to study the analytical merits. The developed method yielded a good detection limit of 0.01 ∼ 0.37 ng/mL, 0.01 ∼ 0.32 ng/ml, and 0.01 ∼ 0.27 ng/mL for four target analytes in the plasma, serum, and urine matrices. Moreover, extraction recoveries ranged from 85.11 - 113.57% (for plasma), 89.63 - 110.47% (for serum), and 87.44 -106.79% (for urine samples) with 8.78% RSD. In addition, the method exhibited good R2 values of 0.999 for all four target analytes, and the specificity and carryover study revealed no carryover effect from the UHPLC-MS/MS system for determining the apixaban, dabigatran, and their metabolites. Due to the above advantages, the developed analytical technique was applied to examine 11 real-time clinical patients' samples, and the observed results were satisfactory for all three different sample matrices. Therefore, this analytical method can be applied for biomonitoring apixaban, dabigatran, and their two major metabolites with high sensitivity in a short time for various clinical applications.

Potential exposure of native wildlife to anticoagulant rodenticides in Gran Canaria (Canary Islands, Spain): Evidence from residue analysis of the invasive California Kingsnake (Lampropeltis californiae)

Anticoagulant rodenticides (ARs), particularly second-generation compounds (SGARs), are extensively used in pest management, impacting non-target wildlife. The California kingsnake (Lampropeltis californiae), an invasive species in Gran Canaria, is under a control plan involving capture and euthanasia. This research aimed to detect 10 different ARs in these snakes, explore geographical and biometrical factors influencing AR exposure, and assess their potential as sentinel species for raptors, sharing similar foraging habits. Liver samples from 360 snakes, euthanized between 2021 and 2022, were analysed for ARs using LC-MS/MS. Results showed all detected rodenticides were SGARs, except for one instance of diphacinone. Remarkably, 90 % of the snakes tested positive for ARs, with over half exposed to multiple compounds. Brodifacoum was predominant, found in over 90 % of AR-positive snakes, while bromadiolone and difenacoum were also frequently detected but at lower levels. The study revealed that larger snakes and those in certain geographic areas had higher AR concentrations. Snakes in less central or more peripheral areas showed lower levels of these compounds. This suggests a correlation between the snakes' size and distribution with the concentration of ARs in their bodies. The findings indicate that the types and prevalence of ARs in California kingsnakes on Gran Canaria mirror those in the island's raptors. This similarity suggests that the kingsnake could serve as a potential sentinel species for monitoring ARs in the ecosystem. However, further research is necessary to confirm their effectiveness in this role.

Intraspecific and geographical variation in rodenticide exposure among common kestrels in Tenerife (Canary Islands)

This study assesses the impact of second-generation anticoagulant rodenticides (SGARs) on the common kestrel (Falco tinnunculus canariensis) in Tenerife, Canary Islands. The analysis of 390 liver samples over 19 years using HPLC-MS/MS showed that 93.1 % of kestrels were exposed to SGARs in this island. A notable shift in SGAR profiles was observed, with bromadiolone and flocoumafen decreasing, while brodifacoum levels increased sharply from 2018 onwards. Comparatively, Tenerife kestrels had a higher detection frequency of SGARs (93.1 %) than those in the rest of the islands of the archipelago (68.2 %), with median concentrations nearly double (∑AR = 180.9 vs 102.4 ng/g liver, P < 0.0001). Furthermore, on average, kestrels from Tenerife were found to have a higher number of different rodenticide compounds per individual. A Generalized Linear Model (GLM) analysis revealed that several factors contribute to the likelihood of SGAR exposure: being an adult kestrel, the enactment of legal restrictions on SGAR bait concentrations in 2018, higher livestock density, and greater human population density. These findings suggest that both bioaccumulation over the birds' lifespans and environmental factors related to human and agricultural activity are influencing the levels of SGARs detected. Alarmingly, 44.7 % of kestrels had SGAR levels above the toxicity threshold established for other raptor species (200 ng/g liver), signaling a high poisoning risk. This is despite EU regulations to protect wildlife, with our findings indicating an increase in both exposure rates and SGAR concentrations since these laws were enacted. The data highlight a critical environmental threat to endemic species on islands like Tenerife. The common kestrel, not considered globally endangered, is nonetheless facing regional threats from SGAR contamination. These results emphasize the urgent need for effective regulations to address the persistent and growing impact of SGARs on island biodiversity.

Purification, Characterization and Evaluation of the Anticoagulant Effect of an Uncompetitive Trypsin Inhibitor obtained from Bauhinia pulchella (Benth) Seeds

INTRODUCTION

Trypsin inhibitors (TIs) have the ability to competitively or non-competitively bind to trypsin and inhibit its action. These inhibitors are commonly found in plants and are used in protease inhibition studies involved in biochemical pathways of pharmacological interest.

OBJECTIVES

This work aimed to purify a trypsin inhibitor from Bauhinia pulchella seeds (BpuTI), describing its kinetic mechanism and anticoagulant effect.

METHODS

Affinity chromatography, protein assay, and SDS-PAGE were used to purify the inhibitor. Mass spectrometry, inhibition assays, and enzyme kinetics were used to characterize the inhibitor. In vitro assays were performed to verify its ability to prolong blood clotting time.

RESULTS

Affinity chromatography on a Trypsin-Sepharose 4B column gave a yield of 43.1. BpuTI has an apparent molecular mass of 20 kDa with glycosylation (1.15%). Protein identification was determined by MS/MS, and BpuTI showed similarity to several Kunitz-type trypsin inhibitors. BpuTI inhibited bovine trypsin as an uncompetitive inhibitor with IC50 (3 x 10-6 M) and Ki (1.05 x 10-6 M). Additionally, BpuTI showed high stability to temperature and pH variations, maintaining its activity up to 100ºC and in extreme pH ranges. However, the inhibitor was susceptible to reducing agents, such as DTT, which completely abolished its activity. BpuTI showed an anticoagulant effect in vitro at a concentration of 33 μM, prolonging clotting time by 2.6 times.

CONCLUSION

Our results suggest that BpuTI can be a biological tool to be used in blood clotting studies.

Silent killers? The widespread exposure of predatory nocturnal birds to anticoagulant rodenticides

Anticoagulant rodenticides (ARs) influence predator populations and threaten the stability of ecosystems. Understanding the prevalence and impact of rodenticides in predators is crucial to inform conservation planning and policy. We collected dead birds of four nocturnal predatory species across differing landscapes: forests, agricultural, urban. Liver samples were analysed for eight ARs: three First Generation ARs (FGARs) and five SGARs (Second Generation ARs). We investigated interspecific differences in liver concentrations and whether landscape composition influenced this. FGARs were rarely detected, except pindone at low concentrations in powerful owls Ninox strenua. SGARs, however, were detected in every species and 92 % of birds analysed. Concentrations of SGARs were at levels where potential toxicological or lethal impacts would have occurred in 33 % of powerful owls, 68 % of tawny frogmouths Podargus strigoides, 42 % of southern boobooks N. bookbook and 80 % of barn owls Tyto javanica. When multiple SGARs were detected, the likelihood of potentially lethal concentrations of rodenticides increased. There was no association between landscape composition and SGAR exposure, or the presence of multiple SGARs, suggesting rodenticide poisoning is ubiquitous across all landscapes sampled. This widespread human-driven contamination in wildlife is a major threat to wildlife health. Given the high prevalence and concentrations of SGARs in these birds across all landscape types, we support the formal consideration of SGARs as a threatening process. Furthermore, given species that do not primarily eat rodents (tawny frogmouths, powerful owls) have comparable liver rodenticide concentrations to rodent predators (southern boobook, eastern barn owl), it appears there is broader contamination of the food-web than anticipated. We provide evidence that SGARs have the potential to pose a threat to the survival of avian predator populations. Given the functional importance of predators in ecosystems, combined with the animal welfare impacts of these chemicals, we propose governments should regulate the use of SGARs.

Validation and interlaboratory comparison of anticoagulant rodenticide analysis in animal livers using ultra-performance liquid chromatography-mass spectrometry

Anticoagulant rodenticides (ARs) are used to control rodent populations. Poisoning of non-target species can occur by accidental consumption of commercial formulations used for rodent control. A robust method for determining ARs in animal tissues is important for animal postmortem diagnostic and forensic purposes. We evaluated an ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS) method to quantify 8 ARs (brodifacoum, bromadiolone, chlorophacinone, coumachlor, dicoumarol, difethialone, diphacinone, warfarin) in a wide range of animal (bovine, canine, chicken, equine, porcine) liver samples, including incurred samples. We further evaluated UPLC-MS in 2 interlaboratory comparison (ILC) studies; one an ILC exercise (ICE), the other a proficiency test (PT). The limits of detection of UPLC-MS were 0.3-3.1 ng/g, and the limits of quantification were 0.8-9.4 ng/g. The recoveries obtained using UPLC-MS were 90-115%, and relative SDs were 1.2-13% for each of the 8 ARs for the 50, 500, and 2,000 ng/g spiked liver samples. The overall accuracy from the laboratories participating in the 2 ILC studies (4 and 11 laboratories for ICE and PT studies, respectively) were 86-118%, with relative repeatability SDs of 3.7-11%, relative reproducibility SDs of 7.8-31.2%, and Horwitz ratio values of 0.5-1.5. Via the ILC studies, we verified the accuracy of UPLC-MS for AR analysis in liver matrices and demonstrated that ILC can be utilized to evaluate performance characteristics of analytical methods.

Effects of ex vivo blood anticoagulation and preanalytical processing time on the proteome content of platelets

BACKGROUND

Ex vivo assays of platelet function critically inform mechanistic and clinical hematology studies, where effects of divergent blood processing methods on platelet composition are apparent, but unspecified.

OBJECTIVE

Here, we evaluate how different blood anticoagulation options and processing times affect platelet function and protein content ex vivo.

METHODS

Parallel blood samples were collected from healthy human donors into sodium citrate, acid citrate dextrose, EDTA or heparin, and processed over an extended time course for functional and biochemical experiments, including platelet proteome quantification with multiplexed tandem mass tag (TMT) labeling and triple quadrupole mass spectrometry (MS).

RESULTS

Each anticoagulant had time-dependent effects on platelet function in whole blood. For instance, heparin enhanced platelet agonist reactivity, platelet-monocyte aggregate formation and platelet extracellular vesicle release, while EDTA increased platelet α-granule secretion. Following platelet isolation, TMT-MS quantified 3357 proteins amongst all prepared platelet samples. Altogether, >400 proteins were differentially abundant in platelets isolated from blood processed at 24 h versus 1 h post-phlebotomy, including proteins pertinent to membrane trafficking and exocytosis. Anticoagulant-specific effects on platelet proteomes included increased complement system and decreased α-granule proteins in platelets from EDTA-anticoagulated blood. Platelets prepared from heparinized blood had higher levels of histone and neutrophil-associated proteins in a manner related to neutrophil extracellular trap (NET) formation and platelet:NET interactions in whole blood ex vivo.

CONCLUSION

Our results demonstrate that different anticoagulants routinely used for blood collection have varying effects on platelets ex vivo, where methodology-associated alterations in platelet proteome may influence mechanistic, translational and biomarker studies.

Anticoagulant rodenticide exposure in raptors from Ontario, Canada

Anticoagulant rodenticides (ARs) are used globally to control rodent pest infestations in both urban and agricultural settings. It is well documented that non-target wildlife, including predatory birds, are at risk for secondary anticoagulant exposure and toxicosis through the prey they consume. However, there have been no large-scale studies of AR exposure in raptors in Ontario, Canada since new Health Canada legislation was implemented in 2013 in an attempt to limit exposure in non-target wildlife. Our objective was to measure levels of ARs in wild raptors in southern Ontario to assess their exposure. We collected liver samples from 133 raptors representing 17 species submitted to the Canadian Wildlife Health Cooperative (CWHC) in Ontario, Canada, between 2017 and 2019. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantitatively assess the level of exposure to 14 first- and second-generation ARs. Detectable levels of one or more ARs were found in 82 of 133 (62%) tested raptors, representing 12 species. The most commonly detected ARs were bromadiolone (54/133), difethialone (40/133), and brodifacoum (33/133). Of AR-positive birds, 34/82 (42%) contained residues of multiple (> 1) anticoagulant compounds. Our results indicate that AR exposure is common in raptors living in southern Ontario, Canada. Our finding that brodifacoum, difethialone, and bromadiolone were observed alone or in combination with one another in the majority of our sampled raptors indicates that legislative changes in Canada may not be protecting non-target wildlife as intended.

Widespread exposure of powerful owls to second-generation anticoagulant rodenticides in Australia spans an urban to agricultural and forest landscape

The powerful owl (Ninox strenua) is a threatened apex predator that consumes mainly arboreal marsupial prey. Low density populations reside in urban landscapes where their viability is tenuous. The catalyst for this research was the reported death of eight powerful owls around Melbourne, Australia, in less than one year (2020/2021). Eighteen deceased owls were toxicologically screened. We assessed toxic metals (Mercury Hg, Lead Pb, Cadmium Cd and Arsenic As) and anticoagulant rodenticides (ARs) in liver (n = 18 owls) and an extensive range of agricultural chemicals in muscle (n = 14). Almost all agricultural chemicals were below detection limits except for p,p-DDE, which was detected in 71% of birds at relatively low levels. Toxic metals detected in some individuals were generally at low levels. However, ARs were detected in 83.3% of powerful owls. The most common second-generation anticoagulant rodenticide (SGAR) detected was brodifacoum, which was present in every bird in which a rodenticide was detected. Brodifacoum was often present at toxic levels and in some instances at potentially lethal levels. Presence of brodifacoum was detected across the complete urban-forest/agriculture gradient, suggesting widespread exposure. Powerful owls do not scavenge but prey upon arboreal marsupials, and generally not rodents, suggesting that brodifacoum is entering the powerful owl food web via accidental or deliberate poisoning of non-target species (possums). We highlight a critical need to investigate SGARs in food webs globally, and not just in species directly targeted for poisoning or their predators.

Exposure of predatory and scavenging birds to anticoagulant rodenticides in France: Exploration of data from French surveillance programs

Wild raptors are widely used to assess exposure to different environmental contaminants, including anticoagulant rodenticides (ARs). ARs are used on a global scale for rodent control, and act by disruption of the vitamin K cycle that results in haemorrhage usually accompanied by death within days. Some ARs are highly persistent and bioaccumulative, which can cause significant exposure of non-target species. We characterized AR exposure in a heterogeneous sample of dead raptors collected over 12 years (2008-2019) in south-eastern France. Residue analysis of 156 liver samples through LC-MS/MS revealed that 50% (78/156) were positive for ARs, with 13.5% (21/156) having summed second-generation AR (SGAR) concentrations >100 ng/g ww. While SGARs were commonly detected (97.4% of positive samples), first-generation ARs were rarely found (7.7% of positive samples). ARs were more frequently detected and at greater concentration in predators (prevalence: 82.5%) than in scavengers (38.8%). Exposure to multiple ARs was common (64.1% of positive samples). While chlorophacinone exposure decreased over time, an increasing exposure trend was observed for the SGAR brodifacoum, suggesting that public policies may not be efficient at mitigating risk of exposure for non-target species. Haemorrhage was observed in 88 birds, but AR toxicosis was suspected in only 2 of these individuals, and no difference in frequency of haemorrhage was apparent in birds displaying summed SGAR levels above or below 100 ng/g ww. As for other contaminants, 17.2% of liver samples (11/64) exhibited Pb levels compatible with sub-clinical poisoning (>6 μg/g dw), with 6.3% (4/64) above the threshold for severe/lethal poisoning (>30 μg/g dw). Nine individuals with Pb levels >6 μg/g dw also had AR residues, demonstrating exposure to multiple contaminants. Broad toxicological screening for other contaminants was positive for 18 of 126 individuals, with carbofuran and mevinphos exposure being the suspected cause of death of 17 birds. Our findings demonstrate lower but still substantial AR exposure of scavenging birds compared to predatory birds, and also illustrate the complexity of diagnosing AR toxicosis through forensic investigations.

Endangered Australian top predator is frequently exposed to anticoagulant rodenticides

Anticoagulant rodenticides (ARs) used to control mammalian pest populations cause secondary exposure of predatory species throughout much of the world. It is important to understand the drivers of non-target AR exposure patterns as context for assessing long-term effects and developing effective mitigation for these toxicants. In Australia, however, little is known about exposure and effects of ARs on predators. We detected AR residues in 74% of 50 opportunistically collected carcasses of the Tasmanian wedge-tailed eagle (Aquila audax fleayi), an endangered apex predator. In 22% of birds tested, or 31% of those exposed, liver concentrations of second generation ARs (SGARs) were >0.1 mg/kg ww. Eagles were exposed to flocoumafen, a toxicant only available from agricultural suppliers, at an exceptionally high rate (40% of birds tested). Liver SGAR concentrations were positively associated with the proportion of agricultural habitat and human population density in the area around where each eagle died. The high exposure rate in a species not known to regularly prey upon synanthropic rodents supports the hypothesis that apex predators are vulnerable to SGARs. Our results indicate that AR exposure constitutes a previously unrecognized threat to Tasmanian wedge-tailed eagles and highlight the importance of efforts to address non-target AR exposure in Australia.

Towards Development of an Anti-Vampire Bat Vaccine for Rabies Management: Inoculation of Vampire Bat Saliva Induces Immune-Mediated Resistance

The common vampire bat (Desmodus rotundus) is a hematophagous species responsible for paralytic rabies and bite damage that affects livestock, humans and wildlife from Mexico to Argentina. Current measures to control vampires, based upon coumarin-derived poisons, are not used extensively due in part to the high cost of application, risks for bats that share roosts with vampires and residual environmental contamination. Observations that vampire bat bites may induce resistance in livestock against vampire bat salivary anticoagulants encourage research into novel vaccine-based alternatives particularly focused upon increasing livestock resistance to vampire salivary components. We evaluated the action of vampire bat saliva-Freund's incomplete adjuvant administered to sheep with anticoagulant responses induced by repeated vampire bites in a control group and examined characteristics of vampire bat salivary secretion. We observed that injections induced a response against vampire bat salivary anticoagulants stronger than by repeated vampire bat bites. Based upon these preliminary findings, we hypothesize the utility of developing a control technique based on induction of an immunologically mediated resistance against vampire bat anticoagulants and rabies virus via dual delivery of appropriate host and pathogen antigens. Fundamental characteristics of host biology favor alternative strategies than simple culling by poisons for practical, economical, and ecologically relevant management of vampire populations within a One Health context.

Analytical Performance Evaluation of Automated Coagulation Analyzer CP3000 for Routine and Special Coagulation Assays

CP3000 coagulation analyzer is a high-throughput, fully automated coagulation analyzer. The objective of this study was to evaluate the analytical performance of CP3000 coagulation system for general and special coagulation analyses. Quality control materials and patient samples were used to evaluate the analytical performance of CP3000 coagulation system. Precision, carryover, linearity, comparability with ACL-TOP 700 coagulation system, and verification of reference range were evaluated or performed according to Clinical and Laboratory Standards Institute guidelines. Within-run and between-run precisions were below 5% for both normal and abnormal ranges. There was no detectable carryover. The linearity of antithrombin and fibrinogen were excellent. The comparability between CP3000 and ACL-TOP 700 coagulation systems was acceptable except for activated partial thromboplastin time and thrombin time due to differences in reagent composition. Reference ranges proposed by the manufacturer were verified to be acceptable. CP3000 coagulation system is a reliable system that can be used to perform routine and special coagulation tests rapidly and accurately. Because of its small footprint as an additional advantage, the implementation of CP3000 coagulation system can be efficient in hospital laboratories of various sizes.

Continued Anticoagulant Rodenticide Exposure of Red-tailed Hawks (Buteo jamaicensis) in the Northeastern United States with an Evaluation of Serum for Biomonitoring

Prior studies (2006-2016) in birds of prey admitted to a wildlife clinic in Massachusetts, USA, revealed widespread exposure to second-generation anticoagulant rodenticides (SGARs) among red-tailed hawks (Buteo jamaicensis, RTHAs). Continued monitoring of species for which historic data are available can reveal trends in exposure that aid in evaluating the effectiveness of risk-mitigation measures. While the majority of exposure-monitoring studies utilize liver tissue collected postmortem, antemortem modalities, such as serum analysis, may be desirable for risk assessments in certain populations. However, the sensitivity of serum for detecting anticoagulant rodenticides (ARs) is not well studied. Paired liver and serum samples from 43 RTHAs were evaluated from 2017 to 2019. In liver tissue, 100% of birds were positive for ARs, with the SGARs brodifacoum, bromadiolone, and difethialone identified most frequently; 91% of birds had liver residues of 2 to 4 ARs. These findings represent the highest exposure both to ARs overall and to multiple ARs in RTHAs compared to previous studies. All birds diagnosed with AR toxicosis (n = 14) were positive for ARs in serum; however, all subclinically exposed birds (n = 29) were negative in serum. These data show that exposure to SGARs remains widespread in RTHAs in this geographic area. In addition, although serum analysis is not sensitive for detecting sublethal exposures in RTHAs, it can potentially support a diagnosis of AR toxicosis in conjunction with other consistent signs. Environ Toxicol Chem 2020;39:2325-2335. © 2020 SETAC.

[Determination of the anticoagulant activity of low molecular weight heparins by micellar electrokinetic chromatography combined with on-column enzymatic reaction]

Low molecular weight heparins (LMWHs) have largely replaced heparin for the treatment and prevention of thrombosis because of their various advantages over unfractionated heparins (UFHs) such as less bleeding, greater bioavailability, and more predictable anticoagulant effects. For special groups of patients, such as pregnant women, children, and patients with renal failure, it is necessary to monitor the anticoagulant activity of LMWHs in the blood. The traditional method used to determine the anticoagulant activity of heparin is the coagulation test. However, the results are various from different laboratories and different reagents. In contrast, the chromogenic substrate method is more accurate, sensitive and is easy to automate. Here, a method for the determination of the anticoagulant activity of LMWHs was developed by using a capillary-electrophoresis-based substrate chromogenic method. In this method, micellar electrokinetic chromatography (MEKC) was used in combination with electrophoretically mediated microanalysis to determine the anti-factor Xa (FXa) activity of LMWHs. The inhibition was measured by employing a chromogenic peptide substrate (CPS) with a p-nitroaniline (p-NA) moiety as the chromophore. The injection end of the capillary was used as a microreactor in which solutions of LMWHs, antithrombin Ⅲ (ATⅢ), FXa and CPS were successively injected and mixed by using diffusion, the transverse diffusion of laminar flow profiles and applied voltage. The reaction product p-NA was separated from unreacted CPS and sample matrix by using the MEKC mode with discontinuous background electrolyte system. The produced p-NA was baseline separated from the other components and detected at 380 nm to obtain maximum sensitivity. The amount of p-NA was inversely proportional to the activity of LMWHs in the sample. To improve the accuracy of quantification and the method repeatability of methods, nitrofurantoin (NF) was selected as the internal standard, which was added to the solution of CPS. The method was validated and used to measure a set of samples. The method is characterized by automation, good repeatability, high sensitivity, and cost-effectiveness. Additionally, the method does not interfere by the sample matrix, and thus can be used to monitor the anticoagulant activity of LMWHs in plasma.

High throughput screening and identification of coagulopathic snake venom proteins and peptides using nanofractionation and proteomics approaches

Snakebite is a neglected tropical disease that results in a variety of systemic and local pathologies in envenomed victims and is responsible for around 138,000 deaths every year. Many snake venoms cause severe coagulopathy that makes victims vulnerable to suffering life-threating haemorrhage. The mechanisms of action of coagulopathic snake venom toxins are diverse and can result in both anticoagulant and procoagulant effects. However, because snake venoms consist of a mixture of numerous protein and peptide components, high throughput characterizations of specific target bioactives is challenging. In this study, we applied a combination of analytical and pharmacological methods to identify snake venom toxins from a wide diversity of snake species that perturb coagulation. To do so, we used a high-throughput screening approach consisting of a miniaturised plasma coagulation assay in combination with a venom nanofractionation approach. Twenty snake venoms were first separated using reversed-phase liquid chromatography, and a post-column split allowed a small fraction to be analyzed with mass spectrometry, while the larger fraction was collected and dispensed onto 384-well plates. After fraction collection, any solvent present in the wells was removed by means of freeze-drying, after which it was possible to perform a plasma coagulation assay in order to detect coagulopathic activity. Our results demonstrate that many snake venoms simultaneously contain both procoagulant and anticoagulant bioactives that contribute to coagulopathy. In-depth identification analysis from seven medically-important venoms, via mass spectrometry and nanoLC-MS/MS, revealed that phospholipase A2 toxins are frequently identified in anticoagulant venom fractions, while serine protease and metalloproteinase toxins are often associated with procoagulant bioactivities. The nanofractionation and proteomics approach applied herein seems likely to be a valuable tool for the rational development of next-generation snakebite treatments by facilitating the rapid identification and fractionation of coagulopathic toxins, thereby enabling specific targeting of these toxins by new therapeutics such as monoclonal antibodies and small molecule inhibitors.

Brodifacoum Toxicity in American Kestrels (Falco sparverius) with Evidence of Increased Hazard on Subsequent Anticoagulant Rodenticide Exposure

A seminal question in ecotoxicology is the extent to which contaminant exposure evokes prolonged effects on physiological function and fitness. A series of studies were undertaken with American kestrels ingesting environmentally realistic concentrations of the second-generation anticoagulant rodenticide (SGAR) brodifacoum. Kestrels fed brodifacoum at 0.3, 1.0, or 3.0 µg/g diet wet weight for 7 d exhibited dose-dependent hemorrhage, histopathological lesions, and coagulopathy (prolonged prothrombin and Russell's viper venom times). Following termination of a 7-d exposure to 0.5 µg brodifacoum/g diet, prolonged blood clotting time returned to baseline values within 1 wk, but brodifacoum residues in liver and kidney persisted during the 28-d recovery period (terminal half-life estimates >50 d). To examine the hazard of sequential anticoagulant rodenticide (AR) exposure, kestrels were exposed to either the first-generation AR chlorophacinone (1.5 µg/g diet) or the SGAR brodifacoum (0.5 µg/g diet) for 7 d and, following a recovery period, challenged with a low dose of chlorophacinone (0.75 µg/g diet) for 7 d. In brodifacoum-exposed kestrels, the challenge exposure clearly prolonged prothrombin time compared to naive controls and kestrels previously exposed to chlorophacinone. These data provide evidence that the SGAR brodifacoum may have prolonged effects that increase the toxicity of subsequent AR exposure. Because free-ranging predatory and scavenging wildlife are often repeatedly exposed to ARs, such protracted toxicological effects need to be considered in hazard and risk assessments. Environ Toxicol Chem 2020;39:468-481. © 2020 SETAC.

Emergency medicine misconceptions: Utility of routine coagulation panels in the emergency department setting

BACKGROUND

Coagulation panels are ordered for a variety of conditions in the emergency department (ED).

OBJECTIVE

This narrative review evaluates specific conditions for which a coagulation panel is commonly ordered but has limited utility in medical decision-making.

DISCUSSION

Coagulation panels consist of partial thromboplastin time (PTT) or activated partial thromboplastin time (aPTT), prothrombin time (PT), and international normalized ratio (INR). These tests evaluate the coagulation pathway which leads to formation of a fibrin clot. The coagulation panel can monitor warfarin and heparin therapy, evaluate for vitamin K deficiency, evaluate for malnutrition or severe systemic disease, and assess hemostatic function in the setting of bleeding. The utility of coagulation testing in chest pain evaluation, routine perioperative assessment, prior to initiation of anticoagulation, and as screening for admitted patients is low, with little to no change in patient management based on results of these panels. Coagulation testing should be considered in systemically ill patients, those with a prior history of bleeding or family history of bleeding, patients on anticoagulation, or patients with active hemorrhage and signs of bleeding. Thromboelastography and rotational thromboelastometry offer more reliable measures of coagulation function.

CONCLUSIONS

Little utility for coagulation assessment is present for the evaluation of chest pain, routine perioperative assessment, initiation of anticoagulation, and screening for admitted patients. However, coagulation panel assessment should be considered in patients with hemorrhage, patients on anticoagulation, and personal history or family history of bleeding.

Spatiotemporal Expression of Anticoagulation Factor Antistasin in Freshwater Leeches

Antistasin, which was originally discovered in the salivary glands of the Mexican leech Haementeria officinalis, was newly isolated from Helobdella austinensis. To confirm the temporal expression of antistasin during embryogenesis, we carried out semi-quantitative RT-PCR. Hau-antistasin1 was uniquely expressed at stage 4 of the cleavage and was strongly expressed in the late stages of organogenesis, as were other antistasin members. In order to confirm the spatial expression of antistasin, we performed fluorescence in situ hybridization in the late stages of organogenesis. The expression of each antistasin in the proboscis showed a similar pattern and varied in expression in the body. In addition, the spatial expression of antistasin orthologs in different leeches showed the possibility of different function across leech species. Hau-antistasin1 was expressed in the same region as hedgehog, which is a known mediator of signal transduction pathway. Hau-antistasin1 is probably a downstream target of Hedgehog signaling, involved in segment polarity signal pathway.

A facile chemiluminescence sensing for ultrasensitive detection of heparin using charge effect of positively-charged AuNPs

Heparin is a glycosaminoglycan with the highest negative charge density of any known biological molecule. Herein, this highly negative charge structure of heparin and the charge effect from positively-charged AuNPs for luminol chemiluminescence (CL) reaction were combined to build a facile and sensitive CL strategy for detection of heparin. The highly negative charge structure of heparin molecules (four negatively-charged side groups per repeat unit) and the effective signal amplification of charge effect from positively-charged AuNPs make this analysis to display high sensitivity for heparin detection, and the detection limit is as low as 0.06 ng/mL. It is about two orders of magnitude lower than the previously reported colorimetric assay and far lower than the current analysis methods. The established CL strategy is to use the electrostatic interaction between heparin and signal probe (positively-charged AuNPs). Since polyanionic heparin has the highest negative charge in biological system, this CL sensing shows high selectivity for the detection of heparin, and hyaluronic acid (HA), an analogue of heparin, cannot cause interference. This CL sensing succeeded in detecting heparin in human serum samples. Besides, polycationic protamine, heparin antidote, can respond to the system's CL signals through its strong interactions with heparin, thus indirectly detecting protamine. For protamine in serum samples, the detection result was basically consistent with Coomassie brilliant blue assay.

Use of blood clotting assays to assess potential anticoagulant rodenticide exposure and effects in free-ranging birds of prey

Non-target wildlife, particularly birds of prey, are widely exposed to and acutely poisoned by anticoagulant rodenticides (ARs). An unresolved issue surrounding such exposure, however, is the potential for sublethal effects. In particular, the consequences of AR exposure and resulting coagulopathy on health and survival of unintentionally exposed animals, which often encounter a multitude of anthropogenic stressors, are understudied. In a wildlife rehabilitation setting, AR intoxication may be masked by more obvious injuries related to collision with vehicles or electrocution, thereby obfuscating proximate from ultimate cause of mortality. An assessment of coagulation function of admitted wildlife may provide a means of identifying animals exhibiting sublethal coagulopathy, and ultimately ensuring provision of appropriate and swift treatment. In conjunction with routine diagnostics for injury and disease, we performed two blood clotting assays (prothrombin time, Russell's viper venom time) affected by vitamin K-dependent coagulopathy of samples from six species of live raptors admitted to a rehabilitation facility. We also measured clotting time in pre-fledgling barn owl chicks (Tyto furcata) from 10 nest sites in Lower Mainland Canada. Prolonged clotting time or failure to form a clot altogether was observed in 23.0% of 61 sampled raptors admitted to the rehabilitation facility. This is a biologically significant proportion of individuals given the fortuitous and likely biased nature by which raptors are found and admitted to rehabilitation facilities. In contrast, there was little evidence of coagulopathy in 19 pre-fledgling barn owl chicks. The utility of avian coagulation tests for diagnosing AR exposure is promising, yet there remains a need to establish species specific reference values and standardize assay methodologies among testing facilities.

First evidence of anticoagulant rodenticides in fish and suspended particulate matter: spatial and temporal distribution in German freshwater aquatic systems

Anticoagulant rodenticides (ARs) have been used for decades for rodent control worldwide. Research on the exposure of the environment and accumulation of these active substances in biota has been focused on terrestrial food webs, but few data are available on the impact of ARs on aquatic systems and water organisms. To fill this gap, we analyzed liver samples of bream (Abramis brama) and co-located suspended particulate matter (SPM) from the German Environmental Specimen Bank (ESB). An appropriate method was developed for the determination of eight different ARs, including first- and second-generation ARs, in fish liver and SPM. Applying this method to bream liver samples from 17 and 18 sampling locations of the years 2011 and 2015, respectively, five ARs were found at levels above limits of quantifications (LOQs, 0.2 to 2 μg kg^-1). For 2015, brodifacoum was detected in 88% of the samples with a maximum concentration of 12.5 μg kg^-1. Moreover, difenacoum, bromadiolone, difethialone, and flocoumafen were detected in some samples above LOQ. In contrast, no first generation AR was detected in the ESB samples. In SPM, only bromadiolone could be detected in 56% of the samples at levels up to 9.24 μg kg^-1. A temporal trend analysis of bream liver from two sampling locations over a period of up to 23 years revealed a significant trend for brodifacoum at one of the sampling locations.

Exposure of non-target small mammals to anticoagulant rodenticide during chemical rodent control operations

The extensive use of anticoagulant rodenticides (ARs) results in widespread unintentional exposure of non-target rodents and secondary poisoning of predators despite regulatory measures to manage and reduce exposure risk. To elucidate on the potential vectoring of ARs into surrounding habitats by non-target small mammals, we determined bromadiolone prevalence and concentrations in rodents and shrews near bait boxes during an experimental application of the poison for 2 weeks. Overall, bromadiolone was detected in 12.6% of all small rodents and insectivores. Less than 20 m from bait boxes, 48.6% of small mammals had detectable levels of bromadiolone. The prevalence of poisoned small mammals decreased with distance to bait boxes, but bromadiolone concentration in the rodenticide positive individuals did not. Poisoned small mammals were trapped up to 89 m from bait boxes. Bromadiolone concentrations in yellow-necked mice (Apodemus flavicollis) were higher than concentrations in bank vole (Myodes glareolus), field vole (Microtus agrestis), harvest mouse (Micromys minutus), and common shrew (Sorex araneus). Our field trials documents that chemical rodent control results in widespread exposure of non-target small mammals and that AR poisoned small mammals disperse away from bating sites to become available to predators and scavengers in large areas of the landscape. The results suggest that the unintentional secondary exposure of predators and scavengers is an unavoidable consequence of chemical rodent control outside buildings and infrastructures.

Anticoagulant rodenticide use, non-target impacts and regulation: A case study from Australia

The impacts of anticoagulant rodenticides (ARs) on non-target wildlife have been well documented in Europe and North America. While these studies are informative, patterns of non-target poisoning of wildlife elsewhere in the world may differ substantially from patterns occurring in Australia and other countries outside of cool temperate regions due to differences in the types of ARs used, patterns of use, legislation governing sales, and potential pathways of secondary exposure. Most of these differences suggest that the extent and severity of AR poisoning in wildlife may be greater in Australia than elsewhere in the world. While many anecdotal accounts of rodenticide toxicity were found - especially in conjunction with government control efforts and island eradications - no published studies have directly tested rodenticide exposure in non-target Australian wildlife in a comprehensive manner. The effects of private and agricultural use of rodenticides on wildlife have not been adequately assessed. Synthesis of reviewed literature suggests that anticoagulant rodenticides may pose previously unrecognised threats to wildlife and indigenous people in Australia and other nations with diverse and abundant reptile faunas relative to countries with cooler climates where most rodenticide ecotoxicology studies have been conducted. To address the identified knowledge gaps we suggest additional research into the role of reptiles as potential AR vectors, potential novel routes of human exposure, and comprehensive monitoring of rodenticide exposure in Australian wildlife, especially threatened and endangered omnivores and carnivores. Additionally, we recommend regulatory action to harmonise Australian management of ARs with existing and developing global norms.

The pediatric acenocoumarol dosing algorithm: the Children Anticoagulation and Pharmacogenetics Study

Essentials A pediatric pharmacogenetic dosing algorithm for acenocoumarol has not yet been developed. We conducted a multicenter retrospective follow-up study in children in the Netherlands. Body surface area and indication explained 45.0% of the variability in dose requirement. Adding the genotypes of VKORC1, CYP2C9 and CYP2C18 to the algorithm increased this to 61.8%.

SUMMARY

Background The large variability in dose requirement of vitamin K antagonists is well known. For warfarin, pediatric dosing algorithms have been developed to predict the correct dose for a patient; however, this is not the case for acenocoumarol. Objectives To develop dosing algorithms for pediatric patients receiving acenocoumarol with and without genetic information. Methods The Children Anticoagulation and Pharmacogenetics Study was designed as a multicenter retrospective follow-up study in Dutch anticoagulation clinics and children's hospitals. Pediatric patients who used acenocoumarol between 1995 and 2014 were selected for inclusion. Clinical information and saliva samples for genotyping of the genes encoding cytochrome P450 (CYP) 2C9, vitamin K epoxide reductase complex subunit 1 (VKORC1), CYP4F2, CYP2C18 and CYP3A4 were collected. Linear regression was used to analyze their association with the log mean stable dose. A stable period was defined as three or more consecutive International Normalized Ratio measurements within the therapeutic range over a period of ≥ 3 weeks. Results In total, 175 patients were included in the study, of whom 86 had a stable period and no missing clinical information (clinical cohort; median age 8.9 years, and 49% female). For 80 of these 86 patients, genetic information was also available (genetic cohort). The clinical algorithm, containing body surface area and indication, explained 45.0% of the variability in dose requirement of acenocoumarol. After addition of the VKORC1, CYP2C9, and CYP2C18 genotypes to the algorithm, this increased to 61.8%. Conclusions These findings show that clinical factors had the largest impact on the required dose of acenocoumarol in pediatric patients. Nevertheless, genetic factors, and especially VKORC1, also explained a significant part of the variability.

A Tier-I leaching risk assessment of three anticoagulant compounds in the forested areas of Hawai'i

The anticoagulant rodenticides brodifacoum, chlorophacinone, and diphacinone have been proposed for broadcast application in some forested areas in Hawai'i to protect rare and endangered native bird species from introduced mice and rats. Groundwater resources in Hawai'i are prone to contamination due to the intrinsic aquifer vulnerability to leaching from the land surface. Because of the hydrogeologic complexity, Hawai'i uses a Tier-I leaching assessment tool, CLERS, to make registration decisions for new or existing chemicals. The CLERS tool uses soil and pesticide properties as well as water recharge through the soil profile in a GIS framework to estimate mass attenuation of the chemicals at a given depth and compares against this attenuation factor against those of a known leacher and a non-leacher. Disturbed soil samples were collected across the state of Hawai'i, including the islands of Hawai'i, Kaho'olawe, Kaua'i, Lana'i, Maui, Moloka'i, and O'ahu, with two sampling locations per island, except for Kaua'i which had three. As only limited information on chemical properties of these anticoagulants in soils is available, laboratory experiments were performed to determine the sorption capacity (K_d) and the degradation rate (T_1/2) of brodifacoum, chlorophacinone, and diphacinone to construct a proper chemical database. Depending on the soil type, T_1/2 values ranged between 37 and 248days for diphacinone, between 39 and 1000days for chlorophacinone, and between 72 and 462days for brodifacoum. These data were used in the CLERS tool to estimate leaching risks for these chemicals primarily in forested areas of the state where the chemicals are likely to be applied. The results from the CLERS tool indicate low risks of leaching of these three compounds into aquifers in five out of six major Hawaiian Islands. Diphacinone showed medium risk of leaching in a few remote areas in Maui.

Rodenticide incidents of exposure and adverse effects on non-raptor birds

Interest in the adverse effects of rodenticides on birds has focused primarily on raptors. However, non-raptor birds are also poisoned (rodenticide exposure resulting in adverse effects including mortality) by rodenticides through consumption of the rodenticide bait and contaminated prey. A literature search for rodenticide incidents (evidence of exposure to a rodenticide, adverse effects, or exposure to placebo baits) involving non-raptor birds returned 641 records spanning the years 1931 to 2016. The incidents included 17 orders, 58 families, and 190 non-raptor bird species. Nineteen anticoagulant and non-anticoagulant rodenticide active ingredients were associated with the incidents. The number of incidents and species detected were compared by surveillance method. An incident was considered to have been reported through passive surveillance if it was voluntarily reported to the authorities whereas the report of an incident found through field work that was conducted with the objective of documenting adverse effects on birds was determined to be from active surveillance. More incidents were reported from passive surveillance than with active surveillance but a significantly greater number of species were detected in proportion to the number of incidents found through active surveillance than with passive surveillance (z=7.61, p<0.01). Results suggest that reliance on only one surveillance method can underestimate the number of incidents that have occurred and the number of species that are affected. Although rodenticides are used worldwide, incident records were found from only 15 countries. Therefore, awareness of the breadth of species diversity of non-raptor bird poisonings from rodenticides may increase incident reportings and can strengthen the predictions of harm characterized by risk assessments.

Development and Validation of Quantitative Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry Assay for Anticoagulant Rodenticides in Liver

Anticoagulant rodenticides (ARs) are used to control rodent populations; however, exposure to nontarget animals occurs. A sensitive and rugged quantitative method was developed, optimized, and validated for eight ARs in liver. Target analytes comprised two chemical classes: hydroxycoumarins (warfarin, coumachlor, dicoumarol, bromadiolone, brodifacoum, and difethialone) and indanediones (diphacinone and chlorophacinone). In this method, liver extracts were cleaned using dispersive solid phase extraction (d-SPE) to remove matrix interferences and analyzed by reverse phase ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Electrospray ionization in negative ion mode combined with multiple reaction monitoring (MRM) using a triple quadrupole mass spectrometer provided simultaneous confirmation and quantitation. Detection limits spanned 0.75-25 ng/g, and lower quantitation limits were established as 50 ng/g. Interassay method accuracy ranged from 92 to 110% across the analytical range (50-2500 ng/g) using matrix-matched calibrants with good repeatability (relative standard deviations 2-16%). Successful method transfer to another laboratory utilizing an Orbitrap mass analyzer, providing high mass accuracy, was assessed by good method reproducibility during blinded study analyses (6-29%; Horwitz ratios (HORRAT) ≤ 1.5).

Characterization of Danaparoid Complex Extractive Drug by an Orthogonal Analytical Approach

Danaparoid sodium salt, is the active component of ORGARAN, an anticoagulant and antithrombotic drug constituted of three glycosaminoglycans (GAGs) obtained from porcine intestinal mucosa extracts. Heparan sulfate is the major component, dermatan sulfate and chondroitin sulfate being the minor ones. Currently dermatan sulfate and chondroitin sulfate are quantified by UV detection of their unsaturated disaccharides obtained by enzymatic depolymerization. Due to the complexity of danaparoid biopolymers and the presence of shared components, an orthogonal approach has been applied using more advanced tools and methods. To integrate the analytical profile, 2D heteronuclear single quantum coherence (HSQC) NMR spectroscopy was applied and found effective to identify and quantify GAG component signals as well as those of some process signatures of danaparoid active pharmaceutical ingredient (API) batches. Analyses of components of both API samples and size separated fractions proceeded through the determination and distribution of the molecular weight (Mw) by high performance size exclusion chromatographic triple detector array (HP-SEC-TDA), chain mapping by LC/MS, and mono- (¹H and ¹³C) and bi-dimensional (HSQC) NMR spectroscopy. Finally, large scale chromatographic isolation and depolymerization of each GAG followed by LC/MS and 2D-NMR analysis, allowed the sequences to be defined and components to be evaluated of each GAG including oxidized residues of hexosamines and uronic acids at the reducing ends.

Novel method for measurement of heparin anticoagulant activity using SPR

A novel method has been developed for the easy measurement of heparin's anticoagulant activity using surface plasmon resonance. The anticoagulant activity of target heparin was evaluated by measuring the competitive antithrombin III binding of analyte heparin in the solution phase and USP heparin immobilized on chip surface. Heparins, obtained from different animal sources, and low molecular weight heparins were analyzed. The results were reproducible and correlated well with the results of chromogenic assays (correlation coefficient r = 0.98 for anti-Xa and r = 0.94 for anti-IIa). This protocol provides many advantages, significantly minimizing time, cost and the complications of chromogenic assay methods.

Microfluidic Fabrication of Colloidal Nanomaterials-Encapsulated Microcapsules for Biomolecular Sensing

Implantable sensors that detect biomarkers in vivo are critical for early disease diagnostics. Although many colloidal nanomaterials have been developed into optical sensors to detect biomolecules in vitro, their application in vivo as implantable sensors is hindered by potential migration or clearance from the implantation site. One potential solution is incorporating colloidal nanosensors in hydrogel scaffold prior to implantation. However, direct contact between the nanosensors and hydrogel matrix has the potential to disrupt sensor performance. Here, we develop a hollow-microcapsule-based sensing platform that protects colloidal nanosensors from direct contact with hydrogel matrix. Using microfluidics, colloidal nanosensors were encapsulated in polyethylene glycol microcapsules with liquid cores. The microcapsules selectively trap the nanosensors within the core while allowing free diffusion of smaller molecules such as glucose and heparin. Glucose-responsive quantum dots or gold nanorods or heparin-responsive gold nanorods were each encapsulated. Microcapsules loaded with these sensors showed responsive optical signals in the presence of target biomolecules (glucose or heparin). Furthermore, these microcapsules can be immobilized into biocompatible hydrogel as implantable devices for biomolecular sensing. This technique offers new opportunities to extend the utility of colloidal nanosensors from solution-based detection to implantable device-based detection.

Use of anticoagulant rodenticides by pest management professionals in Massachusetts, USA

Secondary exposure to chemical rodenticides, specifically second-generation anticoagulant rodenticides (SGARs), poses a threat to non-target wildlife including birds of prey. Federal regulations in the United States currently limit homeowner access to SGARs as a way of minimizing this threat. With legal access to SGARs, pest management professionals (PMPs) represent a potential linkage to non-target exposure. There is limited research focused on rodent control practices, chemical rodenticide preferences, level of concern and awareness, or opinions on rodenticide regulations as they relate to PMPs. An online survey was sent to PMP companies across Massachusetts, USA, between October and November 2015. Thirty-five responses were obtained, a 20 % response rate. The preferred rodent control method among responding PMP companies was chemical rodenticides, specifically the SGAR bromadiolone. Respondents varied in their level of concern regarding the impact of chemical rodenticides on non-target species and showed a low level of awareness regarding SGAR potency and half-life. All responding companies reported using integrated pest management (IPM) strategies, with nearly all utilizing chemical rodenticides at some point. Enhanced education focused on SGAR potency, bioaccumulation potential, exposure routes, and negative impacts on non-target wildlife may improve efforts made by PMPs to minimize risk to wildlife and decrease dependence on chemical rodenticide use. Future studies evaluating use of anticoagulant rodenticide (ARs) by PMPs and the association with AR residues found in non-target wildlife is necessary to determine if current EPA regulations need to be modified to effectively reduce the risk of SGARs to non-target wildlife.

Simultaneous determination of seven anticoagulant rodenticides in agricultural products by gel permeation chromatography and liquid chromatography-tandem mass spectrometry

A sensitive and reliable method for the simultaneous determination of hydroxycoumarin-type (brodifacoum, bromadiolone, coumatetralyl, and warfarin) and indandione-type (chlorophacinone, diphacinone, and pindone) rodenticides in agricultural products by gel permeation chromatography (GPC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The procedure involved extraction of the rodenticides from samples with acetone, followed by liquid-liquid partitioning with hexane/ethyl acetate (1:1, v/v) and 10% sodium chloride aqueous solution, then cleanup using GPC, and finally, analysis using LC-MS/MS. High recoveries from the GPC column were obtained for all rodenticides tested using a mobile phase of acetone/cyclohexane/triethylamine (400:1600:1, v/v/v). An ODS column, which contains low levels of metal impurities, gave satisfactory peak shapes for both hydroxycoumarin- and indandione-type rodenticides in the LC-MS/MS separation. The average recoveries of rodenticides from eight agricultural foods (apple, eggplant, cabbage, orange, potato, tomato, brown rice, and soybean) fortified at 0.0005-0.001 mg/kg ranged from 76 to 116%, except for bromadiolone in orange (53%) and diphacinone in soybean (54%), and the relative standard deviations ranged from 1 to 16%. The proposed method effectively removed interfering components, such as pigments and lipids, and showed high selectivity. In addition, the matrix effects were negligible for most of the rodenticide/food combinations. The results suggest that the proposed method is reliable and suitable for determining hydroxycoumarin- and indandione-type rodenticides in agricultural products.

EDTA analysis on the Roche MODULAR® analyser

Background: Patient specimens can be subject to subtle interference from cross contamination by liquid-based, potassium-containing EDTA anticoagulant, leading to misinterpretation of results. A rapid method for EDTA analysis to detect such contamination is described.

Method: An in-house EDTA assay on the Roche MODULAR® analyser was assessed for accuracy and precision by comparison with an adjusted calcium difference measurement (atomic absorption and o-cresolphthalein complexone colorimetry).

Results: EDTA method versus adjusted calcium difference showed: slope = 1.038 (95% confidence interval [CI] 0.949-1.131); intercept = 0.073 (95% CI 0.018-0.132) mmol/L; r = 0.914; n = 94. However, inter-assay precision of the calcium difference method was estimated to be poorer (coefficient of variation 24.8% versus 3.4% for the automated colorimetric method at an EDTA concentration of 0.25 mmol/L). Unequivocal contamination was observed at an EDTA concentration of -0.2 mmol/L. The automated method showed positive interference from haemolysis and negative interference from oxalate. The method was unaffected by lipaemia (triglycerides <20 mmol/L), icterus (bilirubin <500 μmol/L), glucose (<100 mmol/L), iron (<100 μmol/L), and citrate, phosphate or fluoride (all <2.5 mmol/L).

Conclusion: The automated colorimetric assay described is an accurate, precise and rapid (3 min) means of detecting EDTA contamination of unhaemolysed biochemistry specimens.

Comprehensive characterization of anticoagulant rodenticides in sludge by liquid chromatography-tandem mass spectrometry

The occurrence of 10 commonly used anticoagulant rodenticides in centrifuged sludge of 27 wastewater treatment plants was evaluated using solid-liquid extraction (SLE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Activated carbon, alumina, and Florisil cartridges with methanol/dichloromethane as eluting solvents were tested in combination with primary-secondary amine (PSA) to optimize an efficient sample cleanup. PSA in combination with Florisil was the best methodology to extract anticoagulant rodenticides in sludge providing recoveries between 42 ± 0.5 and 100 ± 2 %. Warfarin, bromadiolone, ferulenol, and coumachlor were the most ubiquitous compounds in sludge at concentrations up to 84.2 ng g(-1) for the latter. Coumatetralyl, dicoumarol, and brodifacoum were detected sporadically at levels between 6.1 and 17.4 ng g(-1). On the contrary, acenocoumarol, difenacoum, and flocoumafen were not detected in any sample. Finally, we estimated the amount of anticoagulant rodenticides discharged via sludge in order to determine the potential impact to agricultural soil according to different sludge usage practices in the region investigated. This study demonstrates that anticoagulant rodenticides are accumulated in sludge during activated sludge treatment and that the application of sludge as fertilizers may pose a future environmental risk, if not controlled.

Snake venom toxins: toxicity and medicinal applications

Snake venoms are complex mixtures of small molecules and peptides/proteins, and most of them display certain kinds of bioactivities. They include neurotoxic, cytotoxic, cardiotoxic, myotoxic, and many different enzymatic activities. Snake envenomation is a significant health issue as millions of snakebites are reported annually. A large number of people are injured and die due to snake venom poisoning. However, several fatal snake venom toxins have found potential uses as diagnostic tools, therapeutic agent, or drug leads. In this review, different non-enzymatically active snake venom toxins which have potential therapeutic properties such as antitumor, antimicrobial, anticoagulating, and analgesic activities will be discussed.

Development of hydrophilic interaction chromatography with quadruple time-of-flight mass spectrometry for heparin and low molecular weight heparin disaccharide analysis

RATIONALE

Heparin and low molecular weight heparin (LMWH) are widely used as clinical anticoagulants. The determination of their composition and structural heterogeneity still challenges analysts.

METHODS

Disaccharide compositional analysis, utilizing heparinase-catalyzed depolymerization, is one of the most important ways to evaluate the sequence, structural composition and quality of heparin and LMWH. Hydrophilic interaction chromatography coupled with quadruple time-of-flight mass spectrometry (HILIC/QTOFMS) has been developed to analyze the resulting digestion products.

RESULTS

HILIC shows good resolution and excellent MS compatibility. Digestion products of heparin and LMWHs afforded up to 16 compounds that were separated using HILIC and analyzed semi-quantitatively. These included eight common disaccharides, two disaccharides derived from chain termini, three 3-O-sulfo-group-containing tetrasaccharides, along with three linkage region tetrasaccharides and their derivatives. Structures of these digestion products were confirmed by mass spectral analysis. The disaccharide compositions of a heparin, two batches of the LMWH, enoxaparin, and two batches of the LMWH, nadroparin, were compared. In addition to identifying disaccharides, 3-O-sulfo-group-containing tetrasaccharides, linkage region tetrasaccharides were observed having slightly different compositions and contents in these heparin products suggesting that they had been prepared using different starting materials or production processes.

CONCLUSIONS

Thus, compositional analysis using HILIC/QTOFMS offers a unique insight into different heparin products.

Analysis of drug-protein binding using on-line immunoextraction and high-performance affinity microcolumns: Studies with normal and glycated human serum albumin

A method combining on-line immunoextraction microcolumns with high-performance affinity chromatography (HPAC) was developed and tested for use in examining drug-protein interactions with normal or modified proteins. Normal human serum albumin (HSA) and glycated HSA were used as model proteins for this work. High-performance immunoextraction microcolumns with sizes of 1.0-2.0 cm × 2.1mm i.d. and containing anti-HSA polyclonal antibodies were developed and tested for their ability to bind normal HSA or glycated HSA. These microcolumns were able to extract up to 82-93% for either type of protein at 0.05-0.10 mL/min and had a binding capacity of 0.34-0.42 nmol HSA for a 1.0 cm × 2.1mm i.d. microcolumn. The immunoextraction microcolumns and their adsorbed proteins were tested for use in various approaches for drug binding studies. Frontal analysis was used with the adsorbed HSA/glycated HSA to measure the overall affinities of these proteins for the drugs warfarin and gliclazide, giving comparable values to those obtained previously using similar protein preparations that had been covalently immobilized within HPAC columns. Zonal elution competition studies with gliclazide were next performed to examine the specific interactions of this drug at Sudlow sites I and II of the adsorbed proteins. These results were also comparable to those noted in prior work with covalently immobilized samples of normal HSA or glycated HSA. These experiments indicated that drug-protein binding studies can be carried out by using on-line immunoextraction microcolumns with HPAC. The same method could be used in the future with clinical samples and other drugs or proteins of interest in pharmaceutical studies or biomedical research.

Determination of S- and R-warfarin enantiomers by using modified HPLC method

Warfarin is a commonly prescribed anticoagulant existing in two enantiomeric forms S- and R-warfarin. Many techniques have been used to analyze warfarin in plasma but less frequently for enantiomeric analysis. One of the HPLC method employed was further simplified and made economical. Method was validated according to ICH guidelines and was found to be sensitive, reliable and less time consuming. For both enantiomers, LLOQ was 12.5 ng/mL. The CV% and accuracy for method were in the range of 0.8-14.6% and 92-107% respectively. The recoveries for both enantiomers were in the range of 86-103.8%. Blood samples were collected from 170 stable patients taking warfarin and S- and R-warfarin levels were determined by this method. Majority of subjects were found to have S/R-warfarin ratio of about 1:2 as reported in previous studies due to rapid clearance of S-enantiomer than R-enantiomer. However individual subjects data was suggestive of presence of slow metabolizers of S-warfarin leading to altered S/R ratio. Previous studies have also pointed out CYP2C9 polymorphism being responsible for such inter-individual differences in S-warfarin metabolism. So plasma warfarin S/R ratio may serve as a useful phenotypic test for CYP2C9 polymorphism.

Ultrasensitive determination of diphacinone by flow injection chemiluminescence: application to quantification in biofluids and photodegradation monitoring in water samples

An ultrasensitive, quick, and simple approach for the determination of pg levels of diphacinone (DPN) by flow injection chemiluminescence (CL) analysis is proposed for the first time. It is based on the quenching effect of DPN on the CL intensity from a luminol-bovine serum albumin (BSA) CL system, for which the CL intensity decrease was linearly proportional to the logarithm of DPN concentration in the range of 5.0 to 5000 pg/mL. The LOD for DPN determination was as low as 2.0 pg/mL (3α a), and the RSD values were less than 5.0%. One determination cycle that included sampling and washing could be performed in 0.5 min with a sample throughput of 120/h under the optimum experimental conditions. This proposed method was successfully applied to determining DPN in human gastric juice and serum samples with recoveries from 91.8 to 114.3%, and to continuous monitoring of the degradation of DPN in water samples exposed to sunlight during 43 h with a variation ratio of 99.99%. The possible interaction behavior of BSA-DPN is briefly discussed.

[Extract of Hirudo medicinalis leeches: biogenic substance for the creation of effective drugs]

Investigations of the extract of medicinal leech Girulux established parameters that enable one to verify the authenticity of related drugs using the characteristics of their UV spectra the and anticoagulant and antithrombin activity. The limits of pH must range from 5.5 to 7.5. Pilot-scale series of medical leech extract are in compliance with terms of "microbiological purity" quality characteristics. The natural storage has been used to assess the temporal stability of leech extract. The obtained characteristics showed that the activity of extract was retained after 3-year storage.

Implications of using different methods to characterise anticoagulant control in patients with second generation mechanical heart valve prostheses

OBJECTIVE

Characterisation of anticoagulant control is fundamental to investigations of its association with clinical outcome. Anticoagulant control depends on several factors. This paper aims to illustrate the implications of different methods for measuring and analysing anticoagulant control in patients with second generation mechanical heart valve prostheses.

METHODS

International normalised ratio (INR) data collected during the 10-year follow-up of a randomised controlled trial were analysed. We considered the influence of: 3 different target INR ranges; anticoagulant control expressed as the proportion of INR readings (PoR) vs. anticoagulant control follow-up time (PoT); 3 ways of describing the profile of anticoagulant control over time.

RESULTS

Different target INR ranges dramatically influenced derived measures of anticoagulant control; the PoT within the target range varied from 88% for the widest to 28% for narrowest range. Overall distributions of PoR and PoT observations were similar but differed by up to ± 20% for individuals; PoT exceeded PoR when control was good but was less than PoR when control was poor. Classifying PoT outside the target range showed that widely varying combinations of PoT too high and too low are possible across individuals.

CONCLUSIONS

Researchers' choices about methods for measuring and quantifying anticoagulant control markedly influence the values derived from INR readings. The use of different methods across studies makes it difficult or impossible to compare findings and to establish an evidence base for clinical practice. Methods for quantifying anticoagulant control should be standardised.

Exposure pathways of anticoagulant rodenticides to nontarget wildlife

Second-generation anticoagulant rodenticides are widely reported to contaminate and poison nontarget wildlife, primarily predatory birds and mammals. Exposure pathways, however, have not been well defined. Here, we examined potential movement of rodenticides from deployment of bait to exposure of small mammals and other biota. At two adjacent working farms, we placed baits containing either brodifacoum or bromadiolone. We monitored movement of those compounds to the surrounding environment by collecting small mammals, birds, and invertebrates. Similar collections were made at a third agricultural setting without active bait deployment, but located among intensive livestock production and regular rodenticide use by farmers. Livers and whole invertebrate samples were analyzed for rodenticides using a sensitive LC-MSMS method. Norway rats (Rattus norvegicus) from both baited and non-baited farms had residues of brodifacoum or bromadiolone, implicating rats as an important exposure pathway to wildlife. Among 35 analyzed nontarget small mammals, a single vole had high hepatic residues (18.6 μ/g), providing some indication of a small mammal pathway. One song sparrow (Melospiza melodia) sample from a baited farm contained 0.073 μg/g of brodifacoum in liver, while 0.39 μg/g of diphacinone was measured in a pool of carrion beetles (Dermestes spp.) from the non-baited farm area, implicating avian and invertebrate components in exposure pathways. Regurgitated pellets of barn owl (Tyto alba) selected randomly from baited farms contained no detectable rodenticide residues, while 90% of owl pellets collected from a variety of farms, and selected for the presence of rat fur, contained detectable anticoagulant residues. We recorded behavior of a captive sample of a representative songbird, the house sparrow (Passer domesticus); they readily entered bait stations and fed on (unloaded) bait.