Ruminant model for hemodialysis cannulation.

BACKGROUND: Preventative strategies that minimize hemodialysis access complications remain limited. OBJECTIVE: This study aimed to address this gap by developing a Caprine cannulation model to investigate the impact of repeated cannulations on vascular access patency rates. RESEARCH DESIGN AND MEASURES: In this pilot study, a meta-analysis was conducted using experimental control data from four trials to explore the impact of Caprine breed (independent variable) on the dependent variables that affect hemodialysis cannulation, including AVF growth, AVF depth, and flow rate. SUBJECTS: Arteriovenous Fistulas (AVFs) were created using the carotid artery and jugular vein in the necks of seven goats from the French alpine, dwarf, and pygmy breeds. All seven AVFs exhibited vessel remodeling patterns similar to that observed in humans and remained patent, enabling hemodialysis access over the 6 month study. RESULTS: Over the course of 18 weeks, a total of 291 cannulations were completed using standard 15 g dialysis needles without complications demonstrating the feasibility of using the Caprine species as a cannulation model. The ease of access coupled with the animals' cooperative behavior further contributes to the suitability of the Caprine species for hemodialysis investigations. Notably, no infections or clinically significant incidents were observed throughout the study. CONCLUSIONS: The stability of AVF patency and flow underscores the viability and potential of the Caprine species animal model as a valuable research platform for exploring interventions aimed at improving vascular access survival in hemodialysis patients.

Mass Decontamination of Companion Dogs in Disaster: Planning for Personnel, Water, and Time Requirements.

OBJECTIVE: The importance of companion animals in the daily lives of people, and the increasing incidence and severity of natural disasters impacting people and their animals, is very well documented. However, despite the advancement of companion animal response capabilities, decontamination remains an inconsistently implemented component of disaster response. The challenge for local authorities is their need for planning factors and protocols specific to companion animal decontamination which are generally lacking. Data is provided on the average time requirements, water use and containment resources necessary, and the personnel required to decontaminate (decon) a large number of companion dogs. METHODS: Sixty-three lightly contaminated, medium weight, short to medium coat, highly tractable dogs (Labradors and Hounds) from a State facility colony were used to determine the water requirements, soap effectiveness, and time required to complete decon (washing/bathing). Data were collected over a 6-mo period using 2 personnel that were randomly assigned to wash the dogs. Difference in weight, bathing time, and water use between groups was evaluated using a 2-tailed 2-sample t-test for independent data. RESULTS: The time and water requirements were significantly different between medium coated dogs and short coated dogs. On average, for a short coated dog, the amount of time to complete decon was 7 min, and the amount of water was 8-10 gal. For medium coated dogs, the time increased to 10-12 min to complete the process and 12-15 gal water. DISCUSSION: The results of this study provide important insights emergency management planners, animal response team members, and community personnel tasked with implementation of mass decontamination of companion dogs following a natural or man-made disaster.

Equine bronchial epithelial cells are susceptible to cell entry with a SARS-CoV-2 pseudovirus but reveal low replication efficiency.

OBJECTIVE: To examine the susceptibility of cultured primary equine bronchial epithelial cells (EBECs) to a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus relative to human bronchial epithelial cells (HBECs). SAMPLE: Primary EBEC cultures established from healthy adult horses and commercially sourced human bronchial epithelial cells (HBECs) were used as a positive control. METHODS: Angiotensin-converting enzyme 2 (ACE2) expression by EBECs was demonstrated using immunofluorescence, western immunoblot, and flow cytometry. EBECs were transduced with a lentivirus pseudotyped with the SARS-CoV-2 spike protein that binds to ACE2 and expresses the enhanced green fluorescent protein (eGFP) as a reporter. Cells were transduced with the pseudovirus at a multiplicity of infection of 0.1 for 6 hours, washed, and maintained in media for 96 hours. After 96 hours, eGFP expression in EBECs was assessed by fluorescence microscopy of cell cultures and quantitative PCR. RESULTS: ACE2 expression in EBECs detected by immunofluorescence, western immunoblotting, and flow cytometry was lower in EBECs than in HBECs. After 96 hours, eGFP expression in EBECs was demonstrated by fluorescence microscopy, and mean ΔCt values from quantitative PCR were significantly (P < .0001) higher in EBECs (8.78) than HBECs (3.24) indicating lower infectivity in EBECs. CLINICAL RELEVANCE: Equine respiratory tract cells were susceptible to cell entry with a SARS-CoV-2 pseudovirus. Lower replication efficiency in EBECs suggests that horses are unlikely to be an important zoonotic host of SARS-CoV-2, but viral mutations could render some strains more infective to horses. Serological and virological monitoring of horses in contact with persons shedding SARS-CoV-2 is warranted.

Using Sentinel Plots to Monitor for Changes in Thrips Susceptibility to MON 88702 Cotton Containing the Cry51Aa2.834_16 Bt Protein.

Transgenic Bt crops are important tools for growers to manage insect pests, but their durability is threatened by the evolution of insect resistance. Implementing a resistance monitoring program is essential to detect and mitigate resistance. For non-high-dose Bt crops, resistance monitoring is challenging, because insect control is not complete, so targeted insects and insect damage will be present even without resistance. Given these challenges, sentinel plots have been used to monitor for insect resistance to non-high-dose crops by assessing changes in the efficacy of a Bt crop over time relative to a non-Bt control. We optimized a sentinel plot resistance monitoring approach for MON 88702 ThryvOn™ cotton, a new non-high-dose Bt product targeting two sucking pest taxa-Lygus (L. lineolaris and L. hesperus) and thrips (Frankliniella fusca and F. occidentalis)-and report here on the thrips monitoring methods and results. Quantifying thrips immatures was the best metric to characterize the impact of the trait, with at least a 40-60% average reduction of thrips immatures on ThryvOn relative to the control cotton at all sites with higher thrips densities. These data can be used within a ThryvOn resistance monitoring program and represent a case study for establishing a resistance monitoring approach for a non-high-dose trait product.

Equine enterocytes actively oxidize l-glutamine, but do not synthesize l-citrulline or l-arginine from l-glutamine or l-proline in vitro.

In livestock species, the enterocytes of the small intestine are responsible for the synthesis of citrulline and arginine from glutamine and proline. At present, little is known about de novo synthesis of citrulline and arginine in horses. To test the hypothesis that horses of different age groups can utilize glutamine and proline for the de novo synthesis of citrulline and arginine, jejunal enterocytes from 19 horses of three different age groups: neonates (n = 4; 7.54 ± 2.36 d of age), adults (n = 9; 6.4 ± 0.35 yr), and aged (n = 6; 22.9 ± 1.0 yr) with healthy gastrointestinal tracts were used in the present study. Enterocytes were isolated from the jejunum and incubated at 37 °C for 30 min in oxygenated (95% O2/5% CO2) Krebs bicarbonate buffer (pH 7.4) containing 5 mM D-glucose and 0 mM, 2-mM L-[U-14C]glutamine, or 2 mM L-[U-14C]proline plus 2 mM L-glutamine. Concentrations of arginine, citrulline, and ornithine in cells plus medium were determined using high-performance liquid chromatography. Results indicate that the rate of oxidation of glutamine to CO2 was high in enterocytes from neonatal horses, but low in cells from adult and aged horses. Enterocytes from all age groups of horses did not degrade proline into CO2. Regardless of age, equine enterocytes formed ornithine from glutamine and proline, but failed to convert ornithine into citrulline and arginine. Because arginine is an essential substrate for the synthesis of not only proteins, but also nitrogenous metabolites (e.g., nitric oxide, polyamines, and creatine), our novel findings have important implications for the nutrition, performance, and health of horses.

The amino acid arginine (Arg) is a precursor for the synthesis of multiple biological molecules including nitric oxide, polyamines, and creatine that are involved in cell proliferation, cellular remodeling, dilation of blood vessels, and phosphocreatine production for a readily available source of energy. Multipurpose capabilities of Arg have increased the interest in its effects in other species and must be evaluated in the horse. Levels of Arg are deficient in the milk of mammals such as humans, cows, sheep, and pigs, but their neonates are capable of synthesizing citrulline and Arg from glutamine and proline in the small intestine. High concentrations of Arg in milk have been observed in the horse, warranting investigation in case that the foal cannot synthesize Arg to support growth and thus rely on milk as the sole source of Arg. To date, no research has determined the endogenous production of Arg in horses to support metabolic and physiological processes; therefore, our experiment quantifies the synthesis of Arg in enterocytes of the small intestine of neonatal, adult, and aged horses. Data collected from this study serve as the necessary first step to determine the Arg requirement in the horse that has over-reaching implications to improve the growth, performance, reproductive efficiency, and to enhance longevity of the horse.

Sequence-Activity Relationships for the Snf7 Insecticidal dsRNA in Chrysomelidae.

The responsiveness of insects to oral delivery of insecticidal dsRNA has been shown to be dependent on dsRNA length and sequence match. Previous work with the western corn rootworm (WCR, Diabrotica virgifera virgifera; Coleoptera: Chrysomelidae) demonstrated that at least one ≥21 nt match must be present in the DvSnf7 dsRNA of approximately ≥60 base-pairs (bp) for activity. Further data is needed on the activity of <21 nt matches along with characterization of relationship between activity and the number of ≥21 nt matches. To characterize the sequence-activity relationship for insecticidal dsRNA further, the activity of orthologous Snf7 dsRNAs with 19, 20, and 21 nt contiguous matches against WCR was compared. Neither 19 nor 20 nt sequence matches were active, supporting that a ≥21 nt sequence match is required for activity. The relationship between the number of 21 nt matches with activity of Snf7 dsRNA orthologs from several Chrysomelid species was characterized using WCR and Colorado potato beetle (CPB, Leptinotarsa decemlineata; Coleoptera Chrysomelidae). For WCR, there was a strong relationship between an increasing number of 21 nt matches and increased activity (i.e., lower LC50 values). A similar relationship was observed for CPB with an exception for a single ortholog, which may be related to the exceptionally high rate of polymorphisms in CPB. Overall, these results demonstrate a general relationship between the number of 21 nt matches and activity, and this relationship could be used to inform a testing and assessment plan for an ecological risk assessment for an insecticidal dsRNA.

Assessing the Potential for Interaction in Insecticidal Activity Between MON 87751 × MON 87701 Produced by Conventional Breeding.

Pyramiding (combining) of plant incorporated protectants (PIPs) with insecticidal activity in genetically engineered crops is a strategy used to improve efficacy as well as delay potential resistance for a specific group of targets. In some countries, a regulatory risk assessment is required for breeding "stacks" expressing multiple PIPs and these countries may require an assessment of potential interaction among the PIPs. This study evaluated whether combining soybean events MON 87551 and MON 87701 results in a toxicological interaction that effects a species that is controlled by each event. MON 87751 coexpresses the Cry1A.105 and Cry2Ab2 proteins and MON 87701 expresses the Cry1Ac protein. EC50 values for MON 87751 and MON 87701 were comparable in diet-incorporation bioassays using corn earworm (Lepidoptera: Noctuidae, Helicoverpa zea) and the observed combined activity of the stack was consistent with predictions of additivity (i.e., no interaction). Under the concentration and response addition models, predicted and observed median effect levels differed by <10%. These results demonstrate independent action at the median effect level between the insecticidal activity of MON 87751 and MON 87701. Taken together, no interaction between these PIPs and acceptable margins of safety for the individual proteins to nontarget organisms, it is appropriate to bridge back to the risk assessments for the individual products that demonstrated environmental safety of stack products containing both MON 87751 and MON 87701.

Characterization of the Activity Spectrum of MON 88702 and the Plant-Incorporated Protectant Cry51Aa2.834_16.

The spectrum of insecticidal activity of Cry51Aa2.834_16 protein targeting hemipteran and thysanopteran insect pests in cotton was characterized by selecting and screening multiple pest and non-pest species, based on representation of ecological functional groups, taxonomic relatedness (e.g. relationship to species where activity was observed), and availability for effective testing. Seven invertebrate orders, comprising 12 families and 17 representative species were screened for susceptibility to Cry51Aa2.834_16 protein and/or the ability of the protein to protect against feeding damage in laboratory, controlled environments (e.g. greenhouse/growth chamber), and/or field studies when present in cotton plants. The screening results presented for Cry51Aa2.834_16 demonstrate selective and limited activity within three insect orders. Other than Orius insidiosus, no activity was observed for Cry51Aa2.834_16 against several groups of arthropods that perform key ecological roles in some agricultural ecosystems (e.g. pollinators, decomposers, and natural enemies).