Publications

Publications from members of the SVM community will be featured here. These publications will be updated monthly.

Neuroanatomy of the spleen: Mapping the relationship between sympathetic neurons and lymphocytes

Murray K, Godinez DR, Brust-Mascher I, Miller EN, Gareau MG, Reardon C.

The nervous system plays a profound regulatory role in maintaining appropriate immune responses by signaling to immune cells. These immune cells, including B- and T-cells, can further act as intermediary messengers, with subsets of B- and T-cells expressing choline acetyltransferase (ChAT), the enzyme required for acetylcholine (ACh) synthesis. Neural control of ACh release from ChAT+ T-cells can have powerful immune implications, regulating lymphocyte trafficking, inflammation, and prevent death due to experimental septic shock. Although ACh release from T-cells has been proposed to occur following norepinephrine (NE) released from sympathetic nerve terminals in the spleen, it is unknown how this communication occurs. While it was proposed that tyrosine hydroxylase (TH+) axons form synapse-like structures with ChAT+ T-cells, there is scant evidence to support or refute this phenomenon. With this in mind, we sought to determine the relative abundance of ChAT+ B- and T-cells in close proximity to TH+ axons, and determine what factors contribute to their localization in the spleen. Using confocal microscopy of tissue sections and three-dimensional imaging of intact spleen, we confirmed that ChAT+ B-cells exceed the number of ChAT+ T-cells, and overall few ChAT+ B- or T-cells are located close to TH+ fibers compared to total numbers. The organized location of ChAT+ lymphocytes within the spleen suggested that these cells were recruited by chemokine gradients. We identified ChAT+ B- and T-cells express the chemokine receptor CXCR5; indicating that these cells can respond to CXCL13 produced by stromal cells expressing the β2 adrenergic receptor in the spleen. Our findings suggest that sympathetic innervation contributes to organization of ChAT+ immune cells in the white pulp of the spleen by regulating CXCL13. Supporting this contention, chemical sympathectomy significantly reduced expression of this chemokine. Together, we demonstrated that there does not appear to be a basis for synaptic neuro-immune communication, and that sympathetic innervation can modulate immune function through altering stromal cell chemokine production. PMID: 28753658

Microscopic and molecular identification of hemotropic mycoplasmas in South American coatis (Nasua nasua)

Cubilla MP, Santos LC, de Moraes W, Cubas ZS, Leutenegger CM, Estrada M, Lindsay LL, Trindade ES, Franco CRC, Vieira RFC, Biondo AW, Sykes JE.

Hemoplasmas were detected in two apparently healthy captive South American coatis (Nasua nasua) from southern Brazil during an investigation for vector-borne pathogens. Blood was subjected to packed cell volume (PCV) determination, a commercial real-time PCR panel for the detection of Anaplasma spp., Babesia spp., Bartonella spp., Hepatozoon spp., Leishmania spp., Mycoplasma haemofelis, 'Candidatus Mycoplasma turicensis', 'Candidatus Mycoplasma haemominutum', Neorickettsia risticii, Rickettsia rickettsii and Leptospira spp., and a pan-hemoplasma conventional PCR assay. PCV was normal, but both coatis tested positive for hemoplasmas and negative for all the remaining pathogens tested. Using different techniques for microscopy (light, confocal or SEM), structures compatible with hemoplasmas were identified. Sequencing of the 16S rRNA gene identified an organism resembling Mycoplasma haemofelis and another hemotropic Mycoplasma sp., with a sequence identity of 96.8% to a Mycoplasma sp. previously detected in capybaras. PMID: 28750863

Developing a 670k genotyping array to tag ~2M SNPs across 24 horse breeds

Schaefer RJ, Schubert M, Bailey E, Bannasch DL, Barrey E, Bar-Gal GK, Brem G, Brooks SA, Distl O, Fries R, Finno CJ, Gerber V1, Haase B, Jagannathan V, Kalbfleisch T, Leeb T, Lindgren G, Lopes MS, Mach N, da Câmara Machado A, MacLeod JN, McCoy A, Metzger J, Penedo C, Polani S, Rieder S, Tammen I, Tetens J, Thaller G, Verini-Supplizi A, Wade CM, Wallner B, Orlando L, Mickelson JR, McCue ME.

BACKGROUND: To date, genome-scale analyses in the domestic horse have been limited by suboptimal single nucleotide polymorphism (SNP) density and uneven genomic coverage of the current SNP genotyping arrays. The recent availability of whole genome sequences has created the opportunity to develop a next generation, high-density equine SNP array. RESULTS: Using whole genome sequence from 153 individuals representing 24 distinct breeds collated by the equine genomics community, we cataloged over 23 million de novo discovered genetic variants. Leveraging genotype data from individuals with both whole genome sequence, and genotypes from lower-density, legacy SNP arrays, a subset of ~5 million high-quality, high-density array candidate SNPs were selected based on breed representation and uniform spacing across the genome. Considering probe design recommendations from a commercial vendor (Affymetrix, now Thermo Fisher Scientific) a set of ~2 million SNPs were selected for a next-generation high-density SNP chip (MNEc2M). Genotype data were generated using the MNEc2M array from a cohort of 332 horses from 20 breeds and a lower-density array, consisting of ~670 thousand SNPs (MNEc670k), was designed for genotype imputation. CONCLUSIONS: Here, we document the steps taken to design both the MNEc2M and MNEc670k arrays, report genomic and technical properties of these genotyping platforms, and demonstrate the imputation capabilities of these tools for the domestic horse. PMID: 28750625

Morbidity and mortality in infant mountain gorillas (Gorilla beringei beringei): A 46-year retrospective review

Hassell JM, Zimmerman D, Cranfield MR, Gilardi K, Mudakikwa A, Ramer J, Nyirakaragire E, Lowenstine LJ.

Long-term studies of morbidity and mortality in free-ranging primates are scarce, but may have important implications for the conservation of extant populations. Infants comprise a particularly important age group, as variation in survival rates may have a strong influence on population dynamics. Since 1968, the Mountain Gorilla Veterinary Project (MGVP, Inc.) and government partners have conducted a comprehensive health monitoring and disease investigation program on mountain gorillas (Gorilla beringei beringei) in Rwanda, Uganda, and the Democratic Republic of the Congo. In an effort to better understand diseases in this species, we reviewed reliable field reports (n = 37), gross post-mortem (n = 66), and histopathology (n = 53) reports for 103 infants (less than 3.5 years) mountain gorillas in the Virunga Massif. Our aim was to conduct the first comprehensive analysis of causes of infant mortality and to correlate histological evidence with antemortem morbidity in infant mountain gorillas. Causes of morbidity and mortality were described, and compared by age, sex, and over time. Trauma was the most common cause of death in infants (56%), followed by respiratory infections and aspiration (13%). Gastrointestinal parasitism (33%), atypical lymphoid hyperplasia (suggestive of infectious disease) (31%), and hepatic capillariasis (25%) were the most significant causes of antemortem morbidity identified post-mortem. Identifying the causes of mortality and morbidity in infants of this critically endangered species will help to inform policy aimed at their protection and guide ante- and post-mortem health monitoring and clinical decision-making in the future. PMID: 28749595

Central and peripheral reservoirs of feline immunodeficiency virus in cats: a review

Eckstrand CD, Sparger EE, Murphy BG.

Infection with feline immunodeficiency virus (FIV), a lentivirus similar to human immunodeficiency virus (HIV), results in lifelong viral persistence and progressive immunopathology in the cat. FIV has the ability to infect and produce infectious virus in a number of different cell types. FIV provirus can also be maintained in a replication-competent but transcriptionally quiescent state, facilitating viral persistence over time. Immediately after the initial infection, FIV infection quickly disseminates to many anatomical compartments within the host including lymphoid organs, gastrointestinal tract and brain. Collectively, the anatomic and cellular compartments that harbour FIV provirus constitute the viral reservoir and contain foci of both ongoing viral replication and transcriptionally restricted virus that may persist over time. The relative importance of the different phenotypes observed for infected cells, anatomic compartment, replication status and size of the reservoir represent crucial areas of investigation for developing effective viral suppression and eradication therapies. In this review, we discuss what is currently known about FIV reservoirs, and emphasize the utility of the FIV-infected cat as a model for the HIV-infected human. PMID: 28749325

SigTree: A Microbial Community Analysis Tool to Identify and Visualize Significantly Responsive Branches in a Phylogenetic Tree

Stevens JR, Jones TR, Lefevre M, Ganesan B, Weimer BC.

Microbial community analysis experiments to assess the effect of a treatment intervention (or environmental change) on the relative abundance levels of multiple related microbial species (or operational taxonomic units) simultaneously using high throughput genomics are becoming increasingly common. Within the framework of the evolutionary phylogeny of all species considered in the experiment, this translates to a statistical need to identify the phylogenetic branches that exhibit a significant consensus response (in terms of operational taxonomic unit abundance) to the intervention. We present the R software package SigTree, a collection of flexible tools that make use of meta-analysis methods and regular expressions to identify and visualize significantly responsive branches in a phylogenetic tree, while appropriately adjusting for multiple comparisons. PMID: 28748045 PMCID: PMC5512180

Ferredoxin reductase is critical for p53-dependent tumor suppression via iron regulatory protein 2

Zhang Y, Qian Y, Zhang J, Yan W, Jung YS, Chen M, Huang E, Lloyd K, Duan Y, Wang J, Liu G, Chen X.

Ferredoxin reductase (FDXR), a target of p53, modulates p53-dependent apoptosis and is necessary for steroidogenesis and biogenesis of iron-sulfur clusters. To determine the biological function of FDXR, we generated a Fdxr-deficient mouse model and found that loss of Fdxr led to embryonic lethality potentially due to iron overload in developing embryos. Interestingly, mice heterozygous in Fdxr had a short life span and were prone to spontaneous tumors and liver abnormalities, including steatosis, hepatitis, and hepatocellular carcinoma. We also found that FDXR was necessary for mitochondrial iron homeostasis and proper expression of several master regulators of iron metabolism, including iron regulatory protein 2 (IRP2). Surprisingly, we found that p53 mRNA translation was suppressed by FDXR deficiency via IRP2. Moreover, we found that the signal from FDXR to iron homeostasis and the p53 pathway was transduced by ferredoxin 2, a substrate of FDXR. Finally, we found that p53 played a role in iron homeostasis and was required for FDXR-mediated iron metabolism. Together, we conclude that FDXR and p53 are mutually regulated and that the FDXR-p53 loop is critical for tumor suppression via iron homeostasis. PMID: 28747430

Ocular localization of mycobacterial lesions in tank-reared juvenile cobia, Rachycentron canadum

Phillips ACN, Suepaul R, Soto E.

Severe clinical mycobacteriosis with consistent ocular lesion localization was diagnosed in a population of 800 juvenile tank-reared Cobia (Rachycentron canadum) which experienced a sudden increase in mortality approximately 5 months after arriving into Trinidad and Tobago from Florida, USA. Moderate daily mortality (15-20 animals per day) persisted for just over 1 month. Moribund fish displayed circling behaviour and had an open-mouth gape upon death. Fish consistently presented with bilateral exophthalmia, corneal cloudiness and hyphema. Non-branching acid-fast rods were detected in aqueous humour touch preparations. Histological analysis revealed severe bilateral intra-ocular granulomatous responses in all specimens. Mycobacterium sp. was identified using a real-time PCR assay detecting the RNA polymerase β-subunit (rpoB) gene in different tissue samples. Specimens did not present with characteristic granulomatous responses usually seen in viscera. To the best of our knowledge, this represents only the third documentation of piscine mycobacterial infection presenting with only localized ocular lesions, and the second documented case of mycobacteriosis in cobia. It is, however, the first documentation of an ocular presentation of mycobacteriosis in a marine species and is the first documentation of such a presentation in cobia. PMID: 28745814

Standing intra-oral extractions of cheek teeth aided by partial crown removal in 165 horses (2010-2016)

Rice MK, Henry TJ.

BACKGROUND:

Diseased cheek teeth in horses often require invasive extraction techniques that carry a high rate of complications. Techniques and instrumentation were developed to perform partial crown removal to aid standing intra-oral extraction of diseased cheek teeth in horses.

OBJECTIVES: To analyse success rates and post-surgical complications in horses undergoing cheek teeth extraction assisted by partial crown removal. STUDY DESIGN: Retrospective cohort study. METHODS: 165 horses with 194 diseased cheek teeth that were extracted orally assisted by partial crown removal between 2010 and 2016 were included. Medical records were analysed, including case details, obtained radiographs, surgical reports and follow-up information. Follow-up information (≥2 months) was obtained for 151 horses (91.5%). 95 horses were examined post-operatively by the authors, 16 horses by the referring veterinarian, and in 40 horses post-operative follow up was obtained by informal telephone interviews with the owner. RESULTS: Successful standing intra-oral extraction of CT was obtained in 164/165 horses (99.4%). Twenty-five of these horses (15.2%) required additional intra-oral extraction methods to complete the extraction, including minimally invasive transbuccal approach (n = 21) and tooth sectioning (n = 4). There was one (0.6%) horse with intra-oral extraction failure that required standing repulsion to complete the extraction. The intra-operative complication of fractured root tips occurred in 11/165 horses (6.7%). Post-operative complications occurred in 6/165 horses (3.6%), including alveolar sequestra (n = 4), mild delay of alveolar healing at two months (n = 1), and development of a persistent draining tract secondary to a retained root tip (n = 1).

MAIN LIMITATIONS: Specialised instrumentation and additional training in the technique are recommended to perform partial crown removal in horses. CONCLUSION: Horses with cheek teeth extraction by partial crown removal have an excellent prognosis for a positive outcome. The term partial coronectomy is proposed for this technique. This article is protected by copyright. PMID: 28744895

Diverse and highly recombinant anelloviruses associated with Weddell seals in Antarctica

Fahsbender E, Burns JM, Kim S, Kraberger S, Frankfurter G, Eilers AA, Shero MR, Beltran R, Kirkham A, McCorkell R, Berngartt RK, Male MF, Ballard G, Ainley DG, Breitbart M, Varsani A.

The viruses circulating among Antarctic wildlife remain largely unknown. In an effort to identify viruses associated with Weddell seals (Leptonychotes weddellii) inhabiting the Ross Sea, vaginal and nasal swabs, and faecal samples were collected between November 2014 and February 2015. In addition, a Weddell seal kidney and South Polar skua (Stercorarius maccormicki) faeces were opportunistically sampled. Using high throughput sequencing, we identified and recovered 152 anellovirus genomes that share 63-70% genome-wide identities with other pinniped anelloviruses. Genome-wide pairwise comparisons coupled with phylogenetic analysis revealed two novel anellovirus species, tentatively named torque teno Leptonychotes weddellii virus (TTLwV) -1 and -2. TTLwV-1 (n = 133, genomes encompassing 40 genotypes) is highly recombinant, whereas TTLwV-2 (n = 19, genomes encompassing three genotypes) is relatively less recombinant. This study documents ubiquitous TTLwVs among Weddell seals in Antarctica with frequent co-infection by multiple genotypes, however, the role these anelloviruses play in seal health remains unknown. PMID: 28744371 PMCID: PMC5518176

The effects of aspirated thickened water on survival and pulmonary injury in a rabbit model

Nativ-Zeltzer N, Kuhn MA, Imai DM, Traslavina RP, Domer AS, Litts JK, Adams B, Belafsky PC.

OBJECTIVES/HYPOTHESIS: Liquid thickeners are one of the most frequently utilized treatment strategies for persons with oropharyngeal swallowing dysfunction. The effect of commercially available thickeners on lung injury is uncertain. The purpose of this study was to compare the effects of aspiration of water alone, xanthan gum (XG)-thickened water, and cornstarch (CS)-thickened water on survival and lung morphology in a rabbit model.

STUDY DESIGN: Animal model. Prospective small animal clinical trial. METHODS: Adult New Zealand White rabbits (n = 24) were divided into three groups of eight rabbits. The groups underwent 3 consecutive days of 1.5 mL/kg intratracheal instillation of water (n = 8), XG-thickened water (n = 8), and CS-thickened water (n = 8). The animals were euthanized on day 4, and survival and pulmonary histopathology were compared between groups. RESULTS: In all, 12.5% of rabbits (n = 8) instilled with CS-thickened water survived until the endpoint of the study (day 4). All animals instilled with water (n = 8) or XG-thickened water (n = 8) survived. A mild increase in intra-alveolar hemorrhage was observed for the animals instilled with CS-thickened water compared to the other groups (P < .05). In the groups that survived to the endpoint of the study, instillation of water thickened with XG resulted in greater pulmonary inflammation, pulmonary interstitial congestion, and alveolar edema than water alone (P < .05). CONCLUSIONS: These data suggest that 3 consecutive days of 1.5 mg/kg of aspirated CS-thickened water are fatal, and that XG-thickened water is more injurious than aspirated water alone. Additional research is necessary to further delineate the dangers of aspirated thickened liquids. PMID: 28730738

Evolutionary loss of melanogenesis in the tunicate Molgula occulta

 

Racioppi C, Valoroso MC, Coppola U, Lowe EK, Brown CT, Swalla BJ, Christiaen L, Stolfi A, Ristoratore F.

BACKGROUND: Analyzing close species with diverse developmental modes is instrumental for investigating the evolutionary significance of physiological, anatomical and behavioral features at a molecular level. Many examples of trait loss are known in metazoan populations living in dark environments. Tunicates are the closest living relatives of vertebrates and typically present a lifecycle with distinct motile larval and sessile adult stages. The nervous system of the motile larva contains melanized cells associated with geotactic and light-sensing organs. It has been suggested that these are homologous to vertebrate neural crest-derived melanocytes. Probably due to ecological adaptation to distinct habitats, several species of tunicates in the Molgulidae family have tailless (anural) larvae that fail to develop sensory organ-associated melanocytes. Here we studied the evolution of Tyrosinase family genes, indispensible for melanogenesis, in the anural, unpigmented Molgula occulta and in the tailed, pigmented Molgula oculata by using phylogenetic, developmental and molecular approaches. RESULTS: We performed an evolutionary reconstruction of the tunicate Tyrosinase gene family: in particular, we found that M. oculata possesses genes predicted to encode one Tyrosinase (Tyr) and three Tyrosinase-related proteins (Tyrps) while M. occulta has only Tyr and Tyrp.a pseudogenes that are not likely to encode functional proteins. Analysis of Tyr sequences from various M. occulta individuals indicates that different alleles independently acquired frameshifting short indels and/or larger mobile genetic element insertions, resulting in pseudogenization of the Tyr locus. In M. oculata, Tyr is expressed in presumptive pigment cell precursors as in the model tunicate Ciona robusta. Furthermore, a M. oculata Tyr reporter gene construct was active in the pigment cell precursors of C. robusta embryos, hinting at conservation of the regulatory network underlying Tyr expression in tunicates. In contrast, we did not observe any expression of the Tyr pseudogene in M. occulta embryos. Similarly, M. occulta Tyr allele expression was not rescued in pigmented interspecific M. occulta × M. oculata hybrid embryos, suggesting deleterious mutations also to its cis-regulatory sequences. However, in situ hybridization for transcripts from the M. occulta Tyrp.a pseudogene revealed its expression in vestigial pigment cell precursors in this species. CONCLUSIONS: We reveal a complex evolutionary history of the melanogenesis pathway in tunicates, characterized by distinct gene duplication and loss events. Our expression and molecular data support a tight correlation between pseudogenization of Tyrosinase family members and the absence of pigmentation in the immotile larvae of M. occulta. These results suggest that relaxation of purifying selection has resulted in the loss of sensory organ-associated melanocytes and core genes in the melanogenesis biosynthetic pathway in M. occulta. PMID: 28729899 PMCID: PMC5516394

Genome Sequence of Canine Polyomavirus in Respiratory Secretions of Dogs with Pneumonia of Unknown Etiology

 

Delwart E, Kapusinszky B, Pesavento PA, Estrada M, Seguin MA, Leutenegger CM.

We report here the first canine polyomavirus genome, identified by metagenomics in respiratory secretions of two dogs with severe pneumonia, which tested negative for all canine respiratory pathogens except Mycoplasma cynos The isolate, Canis familiaris polyomavirus 1 (DogPyV-1), is a beta polyomavirus whose closest known LT antigen relatives are primate polyomaviruses. PMID: 28729262

Echocardiographic Parameters of Clinically Normal Geriatric Rhesus Macaques (Macacamulatta)

 

Ueda Y, Gunther-Harrington CT, Cruzen CL, Roberts JA, Stern JA.

The goal of this study was to generate reference intervals for echocardiographic variables in a population of clinically normal geriatric rhesus macaques (Macaca mulatta). To do this, we studied 51 animals (age, 18-29 y; weight, 5.24-17.04 kg). The normal values for cardiac indices, including geometry and systolic and diastolic function, were determined by 2D, M-mode, spectral Doppler, and tissue Doppler echocardiography under ketamine hydrochloride sedation. Statistical correlations between the echocardiographic parameters and age, body weight, sex, and heart rate were investigated. All echocardiographic indices were acquired, and their reference intervals were established. Multiple weak to strong correlations emerged between variables and echocardiographic parameters, but no moderate or strong correlations between body weight or sex and these parameters were noted. Of the 51 geriatric rhesus macaques evaluated, 36 (71%) fulfilled the criteria for diastolic dysfunction. Valve regurgitation, especially tricuspid regurgitation (43%), and aortic regurgitation (51%) also were common in geriatric rhesus macaques. Although these findings merit follow-up, they are unlikely to have clinical significance given their prevalence in these apparently healthy animals. PMID: 28728613

Pharmacokinetics of a Novel, Transdermal Fentanyl Solution in Rhesus Macaques (Macaca mulatta)

Salyards GW, Lemoy MJ, Knych HK, Hill AE, Christe KL.

Rhesus macaques (Macaca mulatta) are the most commonly used NHP biomedical model and experience both research and clinical procedures requiring analgesia. Opioids are a mainstay of analgesic therapy. A novel, transdermal fentanyl solution (TFS) has been developed as a long-acting, single-administration topical opioid and was reported to provide at least 4 d of effective plasma concentrations in beagles (Canis familiaris). To evaluate the pharmacokinetic profile of TFS in healthy adult rhesus macaques, we used a 2-period, 2-treatment crossover study of a single topical administration of 1.3 (25) and 2.6 mg/kg (50 μL/kg) TFS. TFS was applied to the clipped dorsal skin of adult rhesus macaques (n = 6; 3 male, 3 female) under ketamine sedation (10 mg/kg IM). We hypothesized that TFS in rhesus macaques would provide at least 4 d of effective plasma concentrations (assumed to be ≥ 0.2 ng/mL, based on human studies). Plasma fentanyl concentrations were determined by liquid chromatography-tandem mass spectrometry before drug administration and at 0, 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 240, 336, 408, and 504 h afterward. Noncompartmental pharmacokinetic analysis was performed. For each dose (1.3 and 2.6 mg/kg), respectively, the maximal plasma concentration was 1.95 ± 0.40 and 4.19 ± 0.69 ng/mL, occurring at 21.3 ± 4.1 and 30.7 ± 8.7 h; the AUC was 227.3 ± 31.7 and 447.0 ± 49.1 h/ng/mL, and the terminal elimination half-life was 93.7 ± 7.1 and 98.8 ± 5.4 h. No adverse effects were noted after drug administration at either dose. Macaques maintained plasma fentanyl concentrations of 0.2 ng/mL or greater for at least 7 d after 1.3 mg/kg and at least 10 d after 2.6 mg/kg topical administration of TFS. A single TFS dose may provide efficacious analgesia to rhesus macaques and reduce stress, discomfort, and risk to animals and personnel. PMID: 28724494 PMCID: PMC5517334

Hypoxic training increases maximal oxygen consumption in Thoroughbred horses well-trained in normoxia

Ohmura H, Mukai K, Takahashi Y, Takahashi T, Jones JH.

Hypoxic training is effective for improving athletic performance in humans. It increases maximal oxygen consumption (V̇O2max) more than normoxic training in untrained horses. However, the effects of hypoxic training on well-trained horses are unclear. We measured the effects of hypoxic training on V̇O2max of 5 well-trained horses in which V̇O2max had not increased over 3 consecutive weeks of supramaximal treadmill training in normoxia which was performed twice a week. The horses trained with hypoxia (15% inspired O2) twice a week. Cardiorespiratory valuables were analyzed with analysis of variance between before and after 3 weeks of hypoxic training. Mass-specific V̇O2max increased after 3 weeks of hypoxic training (178 ± 10 vs. 194 ± 12.3 ml O2 (STPD)/(kg × min), P<0.05) even though all-out training in normoxia had not increased V̇O2max. Absolute V̇O2max also increased after hypoxic training (86.6 ± 6.2 vs. 93.6 ± 6.6 l O2 (STPD)/min, P<0.05). Total running distance after hypoxic training increased 12% compared to that before hypoxic training; however, the difference was not significant. There were no significant differences between pre- and post-hypoxic training for end-run plasma lactate concentrations or packed cell volumes. Hypoxic training may increase V̇O2max even though it is not increased by normoxic training in well-trained horses, at least for the durations of time evaluated in this study. Training while breathing hypoxic gas may have the potential to enhance normoxic performance of Thoroughbred horses. PMID: 28721122 PMCID: PMC5506448

Aldehyde dehydrogenase 1 a1 regulates energy metabolism in adipocytes from different species

 

Yang K, Adin C, Shen Q, Lee LJ, Yu L, Fadda P, Samogyi A, Ham K, Xu L, Gilor C, Ziouzenkova O.

BACKGROUND: Survival and longevity of xenotransplants depend on immune function and ability to integrate energy metabolism between cells from different species. However, mechanisms for interspecies cross talk in energy metabolism are not well understood. White adipose tissue stores energy and is capable of mobilization and dissipation of energy as heat (thermogenesis) by adipocytes expressing uncoupling protein 1 (Ucp1). Both pathways are under the control of vitamin A metabolizing enzymes. Deficient retinoic acid production in aldehyde dehydrogenase 1 A1 (Aldh1a1) knockout adipocytes (KO) inhibits adipogenesis and increases thermogenesis. Here we test the role Aldh1a1 in regulation of lipid metabolism in xenocultures. METHODS:  Murine wide-type (WT) and KO pre-adipocytes were encapsulated into a poly-L-lysine polymer that allows exchange of humoral factors <32kD via nanopores. Encapsulated murine adipocytes were co-incubated with primary differentiated canine adipocytes. Then, expression of adipogenic and thermogenic genes in differentiated canine adipocytes was detected by real-time polymerase chain reaction (PCR). The regulatory factors in WT and KO cells were identified by comparison of secretome using proteomics and in transcriptome by gene microarray. RESULTS: Co-culture of encapsulated mouse KO vs WT adipocytes increased expression of peroxisome proliferator-activated receptor gamma (Pparg), but reduced expression of its target genes fatty acid binding protein 4 (Fabp4), and adipose triglyceride lipase (Atgl) in canine adipocytes, suggesting inhibition of PPARγ activation. Co-culture with KO adipocytes also induced expression of Ucp1 in canine adipocytes compared to expression in WT adipocytes. Cumulatively, murine KO compared to WT adipocytes decreased lipid accumulation in canine adipocytes. Comparative proteomics revealed significantly higher levels of vitamin A carriers, retinol binding protein 4 (RBP4), and lipokalin 2 (LCN2) in KO vs WT adipocytes. CONCLUSIONS: Our data demonstrate the functional exchange of regulatory factors between adipocytes from different species for regulation of energy balance. RBP4 and LCN2 appear to be involved in the transport of retinoids for regulation of lipid accumulation and thermogenesis in xenocultures. While the rarity of thermogenic adipocytes in humans and dogs precludes their use for autologous transplantation, our study demonstrates that xenotransplantation of engineered cells could be a potential solution for the reduction in obesity in dogs and a strategy for translation to patients. PMID: 28718514

Targeting ATF5 in Cancer

 Angelastro JM.

The expression of activating transcription factor 5 (ATF5) correlates negatively with patient survival in different types of cancer. ATF5 is important for the survival and proliferation of cancer cells, and can be targeted to selectively trigger cancer cell apoptosis while sparing normal cells. Cell-penetrating peptides combined with a dominant negative ATF5 cargo have recently shown efficacy against brain, breast, melanoma, and prostate cancers. PMID: 28718401

Spatial Patterns and Impacts of Environmental and Climatic Factors on Canine Sinonasal Aspergillosis in Northern California

 

Magro M, Sykes J, Vishkautsan P, Martínez-López B.

Sinonasal aspergillosis (SNA) causes chronic nasal discharge in dogs and has a worldwide distribution, although most reports of SNA in North America originate from the western USA. SNA is mainly caused by Aspergillus fumigatus, a ubiquitous saprophytic filamentous fungus. Infection is thought to follow inhalation of spores. SNA is a disease of the nasal cavity and/or sinuses with variable degrees of local invasion and destruction. While some host factors appear to predispose to SNA (such as belonging to a dolichocephalic breed), environmental risk factors have been scarcely studied. Because A. fumigatus is also the main cause of invasive aspergillosis in humans, unraveling the distribution and the environmental and climatic risk factors for this agent in dogs would be of great benefit for public health studies, advancing understanding of both distribution and risk factors in humans. In this study, we reviewed electronic medical records of 250 dogs diagnosed with SNA between 1990 and 2014 at the University of California Davis Veterinary Medical Teaching Hospital (VMTH). A 145-mile radius catchment area around the VMTH was selected. Data were aggregated by zip code and incorporated into a multivariate logistic regression model. The logistic regression model was compared to an autologistic regression model to evaluate the effect of spatial autocorrelation. Traffic density, active composting sites, and environmental and climatic factors related with wind and temperature were significantly associated with increase in disease occurrence in dogs. Results provide valuable information about the risk factors and spatial distribution of SNA in dogs in Northern California. Our ultimate goal is to utilize the results to investigate risk-based interventions, promote awareness, and serve as a model for further studies of aspergillosis in humans. PMID: 28717638 PMCID: PMC5494614

Isolation and characterization of canine placenta-derived mesenchymal stromal cells for the treatment of neurological disorders in dogs

 

Long C, Lankford L, Kumar P, Grahn R, Borjesson DL, Farmer D, Wang A.

Spinal cord injury (SCI) is a devastating disorder that affects humans and dogs. The prognosis of SCI depends on the severity of the injury and can include varying levels of motor and sensory deficits including devastating paraplegia and quadriplegia. Placental mesenchymal stromal cells (PMSCs) have been shown to improve wound healing and possess neuroprotective and immunomodulatory capabilities, but have not yet been clinically tested for the treatment of SCI. This study established a protocol to isolate fetal PMSCs from canine placentas and characterized their paracrine secretion profile and ability to stimulate neurons in vitro to assess their potential as a treatment option for neurological disorders in dogs. Canine PMSCs (cPMSCs) were plastic adherent and capable of trilineage differentiation. cPMSCs expressed typical MSC markers and did not express hematopoietic or endothelial cell markers. Genotyping of cPMSCs revealed fetal rather than maternal origin of the cells. cPMSCs were viable and mitotically expansive in a collagen hydrogel delivery vehicle, and they secreted the immunomodulatory and neurotrophic paracrine factors interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1 (MCP-1), and vascular endothelial growth factor (VEGF). cPMSCs also stimulated the growth of complex neural networks when co-cultured with SH-SY5Y cells, a neuroblastoma cell line used to model neuron growth in vitro. cPMSCs are analogous to human PMSCs. They meet the criteria to be defined as MSCs and represent a potential regenerative therapy option for neurological disorders in dogs with their robust growth in collagen hydrogel, stimulation of neural network formation, and secretion of potent paracrine factors. PMID: 28715613

Animal Models: New Biosensors and Technologies? Including Those for Bone Regrowth and Wound Healing? Advance Animal Health Care While Also Providing a Fertile Testing Ground for Human Health

 

Allen S.

Dogs have bad breath. But when Montana sheep rancher Katy Harjes noticed her collie, Hoshi, had particularly bad breath and facial swelling, she was concerned that the symptoms might be a sign of something serious. She was right; ten-year-old Hoshi had squamous cell carcinoma, a common type of oral tumor found in dogs. The cancer had not metastasized, but the damage was extensive enough that part of Hoshi's lower jaw needed to be removed. Luckily, Hoshi was a suitable candidate for a stateof-the-art bone regrowth procedure developed by Frank Verstraete, B.V.Sc, Dr.Med.Vet., M.Med.Vet., and Boaz Arzi, D.V.M., oral surgeons at the University of California (UC), Davis, School of Veterinary Medicine. Consequently, Katy and Hoshi embarked on a 15-hour road trip to California. PMID: 28715311

Brucella Infection in Asian Sea Otters (Enhydra lutris lutris) on Bering Island, Russia

 

Burgess TL, Johnson CK, Burdin A, Gill VA, Doroff AM, Tuomi P, Smith WA, Goldstein T.

Infection with Brucella spp., long known as a cause of abortion, infertility, and reproductive loss in domestic livestock, has increasingly been documented in marine mammals over the past two decades. We report molecular evidence of Brucella infection in Asian sea otters (Enhydra lutris lutris). Brucella DNA was detected in 3 of 78 (4%) rectal swab samples collected between 2004 and 2006 on Bering Island, Russia. These 78 animals had previously been documented to have a Brucella seroprevalence of 28%, markedly higher than the prevalence documented in sea otters (Enhydra lutris) in North America. All of the DNA sequences amplified were identical to one or more previously isolated Brucella spp. including strains from both terrestrial and marine hosts. Phylogenetic analysis of this sequence suggested that one animal was shedding Brucella spp. DNA with a sequence matching a Brucella abortus strain, whereas two animals yielded a sequence matching a group of strains including isolates classified as Brucella pinnipedialis and Brucella melitensis. Our results highlight the diversity of Brucella spp. within a single sea otter population. PMID: 28715292

Environmentally relevant concentrations of herbicides impact non-target species at multiple sublethal endpoints

 

Hasenbein S, Peralta J, Lawler SP, Connon RE.

There is concern over herbicide exposure effects on aquatic primary production and zooplankton as herbicides are found in aquatic ecosystems at concentrations potentially toxic to phytoplankton. We first aimed to determine the effect concentrations (growth inhibition) and mixture interactions of the herbicides diuron (0.5 to 50μg/L) and hexazinone (0.5 to 40μg/L) on the green algae Pseudokirchneriella subcapitata. Secondly, we evaluated chronic effects on Daphnia magna that were periodically fed on P. subcapitata that had been exposed to low, medium, and high concentrations. We hypothesized that based on the mode of action of the herbicides we would observe additive growth inhibition in algae, and sublethal effects on D. magna. Growth inhibition in P. subcapitata following mixture exposure was most consistent with the concentration addition (CA) concept; while the independent action (IA) model underestimated the combined effect. The lowest observed effect concentrations (LOEC) were 1.50μg/L hexazinone, 1.18μg/L diuron, and 0.125 TU (0.30μg/L diuron×0.12μg/L hexazinone) in the single and binary mixture exposures, respectively. High hexazinone exposure decreased D. magna survival (80% vs. 55.6%). Neonate number was reduced by 13.9% in high mixture and 23.5% in high hexazinone treatments. Gravid body length was reduced by 9.5% following exposure to the high mixture. Herbicide exposure decreased neonate size, especially in later broods. Herbicides decreased the phototaxic responses of neonates in most treatments. Herbicide exposure effects were detected at environmentally relevant concentrations, levels considered to be safe according to current USEPA aquatic life benchmarks, suggesting that these benchmarks need to be updated to improve ecological risk assessment. As herbicides are some of the most applied pesticides worldwide, sublethal endpoints can serve as sensitive early warning tools to indicate their presence and can support regulatory assessments and monitoring to protect aquatic life. PMID: 28711003

Dual Immunization with SseB/Flagellin Provides Enhanced Protection against Salmonella Infection Mediated by Circulating Memory Cells

 

Lee SJ, Benoun J, Sheridan BS, Fogassy Z, Pham O, Pham QM, Puddington L, McSorley SJ.

 The development of a subunit Salmonella vaccine has been hindered by the absence of detailed information about antigenic targets of protective Salmonella-specific T and B cells. Recent studies have identified SseB as a modestly protective Ag in susceptible C57BL/6 mice, but the mechanism of protective immunity remains undefined. In this article, we report that simply combining Salmonella SseB with flagellin substantially enhances protective immunity, allowing immunized C57BL/6 mice to survive for up to 30 d following challenge with virulent bacteria. Surprisingly, the enhancing effect of flagellin did not require flagellin Ag targeting during secondary responses or recognition of flagellin by TLR5. Although coimmunization with flagellin did not affect SseB-specific Ab responses, it modestly boosted CD4 responses. In addition, protective immunity was effectively transferred in circulation to parabionts of immunized mice, demonstrating that tissue-resident memory is not required for vaccine-induced protection. Finally, protective immunity required host expression of IFN-γR but was independent of induced NO synthase expression. Taken together, these data indicate that Salmonella flagellin has unique adjuvant properties that improve SseB-mediated protective immunity provided by circulating memory. PMID: 28710253

Characterization of spaC-type Erysipelothrix sp. isolates causing systemic disease in ornamental fish

 

Pomaranski EK, Reichley SR, Yanong R, Shelley J, Pouder DB, Wolf JC, Kenelty KV, Van Bonn B, Oliaro F, Byrne B, Clothier KA, Griffin MJ, Camus AC, Soto E.

Since 2012, low-to-moderate mortality associated with an Erysipelothrix sp. bacterium has been reported in ornamental fish. Histological findings have included facial cellulitis, necrotizing dermatitis and myositis, and disseminated coelomitis with abundant intralesional Gram-positive bacterial colonies. Sixteen Erysipelothrix sp. isolates identified phenotypically as E. rhusiopathiae were recovered from diseased cyprinid and characid fish. Similar clinical and histological changes were also observed in zebrafish, Danio rerio, challenged by intracoelomic injection. The Erysipelothrix sp. isolates from ornamental fish were compared phenotypically and genetically to E. rhusiopathiae and E. tonsillarum isolates recovered from aquatic and terrestrial animals from multiple facilities. Results demonstrated that isolates from diseased fish were largely clonal and divergent from E. rhusiopathiae and E. tonsillarum isolates from normal fish skin, marine mammals and terrestrial animals. All ornamental fish isolates were PCR positive for spaC, with marked genetic divergence (<92% similarity at gyrB, <60% similarity by rep-PCR) between the ornamental fish isolates and other Erysipelothrix spp. isolates. This study supports previous work citing the genetic variability of Erysipelothrix spp. spa types and suggests isolates from diseased ornamental fish may represent a genetically distinct species. PMID: 28708262

Open-Label Allopregnanolone Treatment of Men with Fragile X-Associated Tremor/Ataxia Syndrome

 

Wang JY, Trivedi AM, Carrillo NR, Yang J, Schneider A, Giulivi C, Adams P, Tassone F, Kim K, Rivera SM, Lubarr N, Wu CY, Irwin RW, Brinton RD, Olichney JM, Rogawski MA, Hagerman RJ.

 Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder affecting approximately 45% of male and 16% of female carriers of the FMR1 premutation over the age of 50 years. Currently, no effective treatment is available. We performed an open-label intervention study to assess whether allopregnanolone, a neurosteroid promoting regeneration and repair, can improve clinical symptoms, brain activity, and magnetic resonance imaging (MRI) measurements in patients with FXTAS. Six patients underwent weekly intravenous infusions of allopregnanolone (2-6 mg over 30 min) for 12 weeks. All patients completed baseline and follow-up studies, though MRI scans were not collected from 1 patient because of MRI contraindications. The MRI scans from previous visits, along with scans from 8 age-matched male controls, were also included to establish patients' baseline condition as a reference. Functional outcomes included quantitative measurements of tremor and ataxia and neuropsychological evaluations. Brain activity consisted of event-related potential N400 word repetition effect during a semantic memory processing task. Structural MRI outcomes comprised volumes of the hippocampus, amygdala, and fluid-attenuated inversion recovery hyperintensities, and microstructural integrity of the corpus callosum. The results of the study showed that allopregnanolone infusions were well tolerated in all subjects. Before treatment, the patients disclosed impairment in executive function, verbal fluency and learning, and progressive deterioration of all MRI measurements. After treatment, the patients demonstrated improvement in executive functioning, episodic memory and learning, and increased N400 repetition effect amplitude. Although MRI changes were not significant as a group, both improved and deteriorated MRI measurements occurred in individual patients in contrast to uniform deterioration before the treatment. Significant correlations between baseline MRI measurements and changes in neuropsychological test scores indicated the effects of allopregnanolone on improving executive function, learning, and memory for patients with relatively preserved hippocampus and corpus callosum, while reducing psychological symptoms for patients with small hippocampi and amygdalae. The findings show the promise of allopregnanolone in improving cognitive functioning in patients with FXTAS and in partially alleviating some aspects of neurodegeneration. Further studies are needed to verify the efficacy of allopregnanolone for treating FXTAS. PMID: 28707277

The impact of forest roads on understory plant diversity in temperate hornbeam-beech forests of Northern Iran

 

Deljouei A, Abdi E, Marcantonio M, Majnounian B, Amici V, Sohrabi H.

Forest roads alter the biotic and abiotic components of ecosystems, modifying temperature, humidity, wind speed, and light availability that, in turn, cause changes in plant community composition and diversity. We aim at investigating and comparing the diversity of herbaceous species along main and secondary forest roads in a temperate-managed hornbeam-beech forest, north of Iran. Sixteen transects along main and secondary forest roads were established (eight transects along main roads and eight along secondary roads). To eliminate the effect of forest type, all transects were located in Carpinetum-Fagetum forests, the dominant forest type in the study area. The total length of each transect was 200 m (100 m toward up slope and 100 m toward down slope), and plots were established along it at different distances from road edge. The diversity of herbaceous plant species was calculated in each plot using Shannon-Wiener index, species richness, and Pielou's index. The results showed that diversity index decreased when distance from road edge increases. This decreasing trend continued up to 60 m from forest road margin, and after this threshold, the index slightly increased. Depending on the type of road (main or secondary) as well as cut or fill slopes, the area showing a statistical different plant composition and diversity measured through Shannon-Wiener, species richness, and Pielou's index is up to 10 m. The length depth of the road edge effect found in main and secondary forest roads was small, but it could have cumulative effects on forest microclimate and forest-associated biota at the island scale. Forest managers should account for the effect of road buildings on plant communities. PMID: 28707253

Mountain gorilla lymphocryptovirus has Epstein-Barr virus-like epidemiology and pathology in infants

Smiley Evans T, Lowenstine LJ, Gilardi KV, Barry PA, Ssebide BJ, Kinani JF, Nizeyimana F, Noheri JB, Cranfield MR, Mudakikwa A, Goldstein T, Mazet JAK, Johnson CK.

Epstein-Barr virus (EBV) infects greater than 90% of humans, is recognized as a significant comorbidity with HIV/AIDS, and is an etiologic agent for some human cancers. The critically endangered mountain gorilla population was suspected of infection with an EBV-like virus based on serology and infant histopathology similar to pulmonary reactive lymphoid hyperplasia (PRLH), a condition associated with EBV in HIV-infected children. To further examine the presence of EBV or an EBV-like virus in mountain gorillas, we conducted the first population-wide survey of oral samples for an EBV-like virus in a nonhuman great ape. We discovered that mountain gorillas are widely infected (n = 143/332) with a specific strain of lymphocryptovirus 1 (GbbLCV-1). Fifty-two percent of infant mountain gorillas were orally shedding GbbLCV-1, suggesting primary infection during this stage of life, similar to what is seen in humans in less developed countries. We then identified GbbLCV-1 in post-mortem infant lung tissues demonstrating histopathological lesions consistent with PRLH, suggesting primary infection with GbbLCV-1 is associated with PRLH in infants. Together, our findings demonstrate that mountain gorilla's infection with GbbLCV-1 could provide valuable information for human disease in a natural great ape setting and have potential conservation implications in this critically endangered species. PMID: 28706209 PMCID: PMC5509654

Are disease reservoirs special? Taxonomic and life history characteristics

 

Plourde BT, Burgess TL, Eskew EA, Roth TM, Stephenson N, Foley JE.

Pathogens that spill over between species cause a significant human and animal health burden. Here, we describe characteristics of animal reservoirs that are required for pathogen spillover. We assembled and analyzed a database of 330 disease systems in which a pathogen spills over from a reservoir of one or more species. Three-quarters of reservoirs included wildlife, and 84% included mammals. Further, 65% of pathogens depended on a community of reservoir hosts, rather than a single species, for persistence. Among mammals, the most frequently identified reservoir hosts were rodents, artiodactyls, and carnivores. The distribution among orders of mammalian species identified as reservoirs did not differ from that expected by chance. Among disease systems with high priority pathogens and epidemic potential, we found birds, primates, and bats to be overrepresented. We also analyzed the life history traits of mammalian reservoir hosts and compared them to mammals as a whole. Reservoir species had faster life history characteristics than mammals overall, exhibiting traits associated with greater reproductive output rather than long-term survival. Thus, we find that in many respects, reservoirs of spillover pathogens are indeed special. The described patterns provide a useful resource for studying and managing emerging infectious diseases. PMID: 28704402

Genetic analysis of optic nerve head coloboma in the Nova Scotia Duck Tolling Retriever identifies discordance with the NHEJ1 intronic deletion (collie eye anomaly mutation)

 

Brown EA, Thomasy SM, Murphy CJ, Bannasch DL.

Collie eye anomaly (CEA) encompasses a spectrum of different ophthalmic phenotypes from clinically inconsequential choroidal hypoplasia to blindness from coloboma of the optic nerve head (ONH). A previous study found a 7.8-kb deletion in intron 4 of the NHEJ1 gene to be associated with CEA. A genetic test based on this association is recommended for many breeds, including the Nova Scotia Duck Tolling Retriever (NSDTR). Collection of ONH coloboma-affected NSDTR showed lack of concordance of the NHEJ1 intronic deletion with ONH coloboma. Using genomewide single nucleotide polymorphism (SNP) genotyping in 7 ONH coloboma-affected NSDTR cases and 47 unaffected NSDTR controls with no ophthalmic signs, one SNP, located on chromosome 7, demonstrated genomewide significance. However, high genomic inflation may have confounded the results. Therefore, the genomewide association study was repeated using EMMAX to control for population structure in the cohort of 7 cases and 47 controls. However, no regions of the genome were significantly associated with ONH coloboma. These results failed to document significant association with the CEA locus. Due to the complex genetic etiology of ONH coloboma, the NHEJ1 intronic deletion test results should be carefully considered when making breeding decisions. If the goal is to select for visually competent dogs, our data suggest that eye examinations of puppies would be more effective as a guide in selection of breeding pairs than relying solely on currently available genetic tests.

© 2017 The Authors. Veterinary Ophthalmology published by Wiley Periodicals, Inc. on behalf of American College of Veterinary Ophthalmologists. PMID: 28702949

Blimp-1-dependent and -independent natural antibody production by B-1 and B-1-derived plasma cells

 

Savage HP, Yenson VM, Sawhney SS, Mousseau BJ, Lund FE, Baumgarth N.

Natural antibodies contribute to tissue homeostasis and protect against infections. They are secreted constitutively without external antigenic stimulation. The differentiation state and regulatory pathways that enable continuous natural antibody production by B-1 cells, the main cellular source in mice, remain incompletely understood. Here we demonstrate that natural IgM-secreting B-1 cells in the spleen and bone marrow are heterogeneous, consisting of (a) terminally differentiated B-1-derived plasma cells expressing the transcriptional regulator of differentiation, Blimp-1, (b) Blimp-1+, and (c) Blimp-1neg phenotypic B-1 cells. Blimp-1neg IgM-secreting B-1 cells are not simply intermediates of cellular differentiation. Instead, they secrete similar amounts of IgM in wild-type and Blimp-1-deficient (PRDM-1ΔEx1A) mice. Blimp-1neg B-1 cells are also a major source of IgG3. Consequently, deletion of Blimp-1 changes neither serum IgG3 levels nor the amount of IgG3 secreted per cell. Thus, the pool of natural antibody-secreting B-1 cells is heterogeneous and contains a distinct subset of cells that do not use Blimp-1 for initiation or maximal antibody secretion. PMID: 28698287

The application of 3-dimensional printing for preoperative planning in oral and maxillofacial surgery in dogs and cats

 

Winer JN, Verstraete FJM, Cissell DD, Lucero S, Athanasiou KA, Arzi B.

OBJECTIVE: To describe the application of 3-dimensional (3D) printing in advanced oral and maxillofacial surgery (OMFS) and to discuss the benefits of this modality in surgical planning, student and resident training, and client education. STUDY DESIGN: Retrospective case series. ANIMALS: Client-owned dogs (n = 28) and cats (n = 4) with 3D printing models of the skulls. METHODS: The medical records of 32 cases with 3D printing prior to major OMFS were reviewed. RESULTS: Indications for 3D printing included preoperative planning for mandibular reconstruction after mandibulectomy (n = 12 dogs) or defect nonunion fracture (n = 6 dogs, 2 cats), mapping of ostectomy location for temporomandibular joint ankylosis or pseudoankylosis (n = 4 dogs), assessment of palatal defects (n = 2 dogs, 1 cat), improved understanding of complex anatomy in cases of neoplasia located in challenging locations (n = 2 dogs, 1 cat), and in cases of altered anatomy secondary to trauma (n = 2 dogs). CONCLUSION: In the authors' experience, 3D printed models serve as excellent tools for OMFS planning and resident training. Furthermore, 3D printed models are a valuable resource to improve clients' understanding of the pet's disorder and the recommended treatment. CLINICAL RELEVANCE: Three-dimensional printed models should be considered viable tools for surgical planning, resident training, and client education in candidates for complex OMFS. PMID: 28688157

Retrospective study of fatal pneumonia in racehorses

 

Carvallo FR, Uzal FA, Diab SS, Hill AE, Arthur RM.

Respiratory diseases have a major impact on racehorses in training and are often cited as the second most common reason of horses failing to perform. Cases were submitted by the California Horse Racing Board to the California Animal Health and Food Safety laboratory for postmortem examination between January 1, 2005 and December 31, 2014. We determined the demographics of racehorses with fatal pneumonia, characterized the pathologic findings in animals with a postmortem diagnosis of respiratory infection, and determined the most significant pathogens associated with lower respiratory tract disease. We analyzed autopsy reports from 83 horses with a diagnosis of pneumonia, bronchopneumonia, and/or pleuropneumonia. The most common presentation was pleuropneumonia (71% of cases), with extensive areas of lytic necrosis and abscesses of the pulmonary parenchyma. Streptococcus equi ssp. zooepidemicus, a normal mucosal commensal of the upper respiratory tract of healthy horses, was the most commonly isolated organism (72% of cases), either in pure culture or accompanied by other aerobic or anaerobic bacteria. Its presence in the pulmonary parenchyma is associated with severe and extensive damage to the lung. Furthermore, this agent has zoonotic potential, which stresses the importance of early detection and proper management of cases of pneumonia in racehorses. PMID: 28681687

Whole-Blood Taurine Concentrations in Cats with Intestinal Disease

Kathrani A, Fascetti AJ, Larsen JA, Maunder C, Hall EJ.

 BACKGROUND: Increased delivery of taurine-conjugated bile acids to the distal bowel can lead to dysbiosis resulting in colitis in mouse models of inflammatory bowel disease. A similar situation also could occur in cats with intestinal disease and might therefore result in decreased whole-body taurine concentration. HYPOTHESIS/OBJECTIVES: To determine whether whole-blood taurine concentrations are decreased at the time of diagnosis in cats with intestinal disease and to correlate concentrations with clinical and laboratory variables. ANIMALS: Twenty-one cats with chronic inflammatory enteropathy and 7 cats with intestinal neoplasia from the University of Bristol.

METHODS: Cats that had undergone a thorough investigation consisting of a CBC, serum biochemistry, serum cobalamin and folate concentrations, transabdominal ultrasound examination and histopathology of intestinal biopsy specimens, as well as additional testing if indicated, were included. Whole-blood from these cats collected at the time of histologic diagnosis and stored in ethylenediaminetetraacetic acid was retrospectively analyzed for taurine with an automated high-performance liquid chromatography amino acid analyzer. RESULTS: Although whole-blood taurine concentrations remained within the reference range, those cats with predominantly large intestinal clinical signs had significantly lower concentrations than did cats with small intestinal and mixed bowel clinical signs (P = 0.033) and this difference also was significant when assessed only in cats with chronic inflammatory enteropathy (P = 0.019). CONCLUSIONS AND CLINICAL IMPORTANCE: Additional studies are needed to determine whether large intestinal signs in cats with chronic inflammatory enteropathy are caused by alterations in the microbiota arising as a consequence of increased delivery of taurine-conjugated bile acids. PMID: 28626960 PMCID: PMC5508316

Increased constitutive nitric oxide production by whole body periodic acceleration ameliorates alterations in cardiomyocytes associated with utrophin/dystrophin deficiency

 

Lopez JR, Kolster J, Zhang R, Adams J.

Duchenne Muscular Dystrophy (DMD) cardiomyopathy is a progressive lethal disease caused by the lack of the dystrophin protein in the heart. The most widely used animal model of DMD is the dystrophin-deficient mdx mouse; however, these mice exhibit a mild dystrophic phenotype with heart failure only late in life. In contrast, mice deficient for both dystrophin and utrophin (mdx/utrn-/-, or dKO) can be used to model severe DMD cardiomyopathy where pathophysiological indicators of heart failure are detectable by 8-10weeks of age. Nitric oxide (NO) is an important signaling molecule involved in vital functions of regulating rhythm, contractility, and microcirculation of the heart, and constitutive NO production affects the function of proteins involved in excitation-contraction coupling. In this study, we explored the efficacy of enhancing NO production as a therapeutic strategy for treating DMD cardiomyopathy using the dKO mouse model of DMD. Specifically, NO production was induced via whole body periodic acceleration (pGz), a novel non-pharmacologic intervention which enhances NO synthase (NOS) activity through sinusoidal motion of the body in a headward-footward direction, introducing pulsatile shear stress to the vascular endothelium and cardiomyocyte plasma membrane. Male dKO mice were randomized at 8weeks of age to receive daily pGz (480cpm, Gz±3.0m/s2, 1h/d) for 4weeks or no treatment, and a separate age-matched group of WT animals (pGz-treated and untreated) served as non-diseased controls. At the conclusion of the protocol, cardiomyocytes from untreated dKO animals had, respectively, 4.3-fold and 3.5-fold higher diastolic resting concentration of Ca2+ ([Ca2+]d) and Na+ ([Na+]d) compared to WT, while pGz treatment significantly reduced these levels. For dKO cardiomyocytes, pGz treatment also improved the depressed contractile function, decreased oxidative stress, blunted the elevation in calpain activity, and mitigated the abnormal increase in [Ca2+]d upon mechanical stress. These improvements culminated in a significant reduction in circulating cardiac troponin T (cTnT) and an extension of the median lifespan of dKO mice from 16 to 31weeks. Treatment with L-NAME (NOS inhibitor) significantly decreased overall lifespan and abolished the cardioprotective properties elicited by pGz. Our results provide evidence that enhancement of NO synthesis by pGz can ameliorate cellular dysfunction in dKO cardiomyocytes and may represent a novel therapeutic intervention in DMD cardiomyopathy patients. PMID: 28623080

Therapeutic Efficacy of Fresh, Allogeneic Mesenchymal Stem Cells for Severe Refractory Feline Chronic Gingivostomatitis

 

Arzi B, Clark KC, Sundaram A, Spriet M, Verstraete FJM, Walker NJ, Loscar MR, Fazel N, Murphy WJ, Vapniarsky N, Borjesson DL.

Mesenchymal stem cells (MSCs) have potent immunomodulatory functions and are a promising therapy for immune-mediated inflammatory disorders. We previously demonstrated the efficacy of fresh, autologous, adipose-derived MSCs (ASCs) to treat feline chronic gingivostomatitis (FCGS), a chronic oral mucosal inflammatory disease similar to human oral lichen planus. Here, we investigate the use of fresh allogeneic ASCs for treatment of FCGS in seven cats. Radiolabeled ASCs were also tracked systemically. Each cat received two intravenous injections of 20 million ASCs, 1 month apart. Oral inflammation, blood lymphocyte subsets, anti-fetal bovine serum antibody levels, ASC crossmatching and serum proteins and cytokine concentrations were determined. Four of the 7 cats (57%) responded to treatment [complete clinical remission (n = 2) or substantial clinical improvement (n = 2)]. Three cats were nonresponders. Prior to therapy, most cats had increased circulating CD8+ T cells, decreased CD8lo cells, and a decreased CD4/CD8 ratio, however clinical resolution was not associated with normalization of these parameters. Nonresponders showed more severe systemic inflammation (neutrophilia, hyperglobulinemia and increased interferon gamma and tumor necrosis factor alpha concentration) prior to ASC therapy. Clinical remission took up to 20 months and no clinical relapse has occurred. A higher fraction of radiolabeled ASCs were identified in the oral cavity of FCGS affected cats than the control cat. The administration of fresh, allogenic ASCs appeared to have lower clinical efficacy with a delayed response as compared to the fresh, autologous ASCs. In addition, the mechanism(s) of action for autologous and allogenic ASCs may differ in this model of oral inflammation. PMID: 28618186

Deep anestrous mares under natural photoperiod treated with recombinant equine FSH (reFSH) and LH (reLH) have fertile ovulations and become pregnant

 

Meyers-Brown GA, Loud MC, Hyland JC, Roser JF.

The most common equine breeding practice to decrease the time to the first ovulation of the year is to use artificial lights starting December 1 in the Northern Hemisphere. It can take 60-90 d for this lighting regimen to induce a fertile ovulation. The success rate for pharmaceutical compounds to carry out the same process has been variable. One compound that did induce an early ovulation was recombinant equine follicle stimulating hormone (reFSH), but neither pregnancy nor cyclicity was established in that study. Starting on December 1, 20 deep-anestrous mares of light horse breeds (4-15 y old) with follicles ≤ 20 mm in diameter and progesterone < 1 ng/mL were maintained under natural photoperiod while 10 control mares were maintained under artificial photoperiod. Starting on February 6, treatment mares were randomly assigned to one of two groups: reFSH (n = 10) or reFSH/reLH (n = 10). Jugular blood samples were collected daily from all mares, and luteinizing hormone (LH), FSH, progesterone (P4), estradiol-17β (E2) and immunoreactive (ir)-inhibin were analyzed by radioimmunoassay (RIA). When the largest follicle reached ≥32 mm in diameter, reFSH treatment was discontinued in both groups while reLH treatment continued in the reFSH/reLH group until a cohort of follicles reached ≥35 mm in diameter. Human chorionic gonadotropin (hCG) was administered intravenously (iv) to induce ovulation, and mares were bred to a fertile stallion every other day until ovulation. Mares receiving either reFSH or reFSH/reLH developed follicles ≥35 mm within 5-6 d of treatment compared with 15.8 ± 3.4 d in the control group. Both reFSH and reFSH/reLH induced ovulation in 100% of the mares within 10 d after treatment resulting in an 80% conception rate and a 70% pregnancy rate for both groups. Conception and pregnancy were designated as either presence of a 14 d old embryo (n = 16) or a fetal heartbeat at 24 d (n = 14), respectively. Only three mares in the control group ovulated within the same treatment period. Later ovulations in the control group resulted in 100% conception and pregnancy rates. At 25 d post-conception, treated mares that were pregnant (n = 7 per group) were administered prostaglandin (PGF2α) to terminate the pregnancy and later returned to estrus. Treatment with reFSH or reFSH/reLH given to deep-anestrous mares under natural photoperiod induced fertile ovulations that resulted in pregnancy and cyclicity when pregnancies were terminated. PMID: 28601147

Susceptibility of Salmonella Biofilm and Planktonic Bacteria to Common Disinfectant Agents Used in Poultry Processing

 

Chylkova T, Cadena M, Ferreiro A, Pitesky M.

Poultry contaminated with Salmonella enterica subsp. enterica are a major cause of zoonotic foodborne gastroenteritis. Salmonella Heidelberg is a common serotype of Salmonella that has been implicated as a foodborne pathogen associated with the consumption of improperly prepared chicken. To better understand the effectiveness of common antimicrobial disinfectants (i.e., peroxyacetic acid [PAA], acidified hypochlorite [aCH], and cetylpyridinium chloride [CPC]), environmental isolates of nontyphoidal Salmonella were exposed to these agents under temperature, concentration, and contact time conditions consistent with poultry processing. Under simulated processing conditions (i.e., chiller tank and dipping stations), the bacteriostatic and bactericidal effects of each disinfectant were assessed against biofilm and planktonic cultures of each organism in a disinfectant challenge. Log reductions, planktonic MICs, and mean biofilm eradication concentrations were computed. The biofilms of each Salmonella isolate were more resistant to the disinfectants than were their planktonic counterparts. Although PAA was bacteriostatic and bactericidal against the biofilm and planktonic Salmonella isolates tested at concentrations up to 64 times the concentrations commonly used in a chiller tank during poultry processing, aCH was ineffective against the same isolates under identical conditions. At the simulated 8-s dipping station, CPC was bacteriostatic against all seven and bactericidal against six of the seven Salmonella isolates in their biofilm forms at concentrations within the regulatory range. These results indicate that at the current contact times and concentrations, aCH and PAA are not effective against these Salmonella isolates in their biofilm state. The use of CPC should be considered as a tool for controlling Salmonella biofilms in poultry processing environments. PMID: 28561639

The Yucatan Minipig Temporomandibular Joint Disc Structure-Function Relationships Support Its Suitability for Human Comparative Studies

 

Vapniarsky N, Aryaei A, Arzi B, Hatcher DC, Hu JC, Athanasiou KA.

Frequent involvement of the disc in temporomandibular joint (TMJ) disorders warrants attempts to tissue engineer TMJ disc replacements. Physiologically, a great degree of similarity is seen between humans and farm pigs (FPs), but the pig's rapid growth confers a significant challenge for in vivo experiments. Minipigs have a slower growth rate and are smaller than FPs, but minipig TMJ discs have yet to be fully characterized. The objective of this study was to determine the suitability of the minipig for TMJ studies by extensive structural and functional characterization. The properties of minipig TMJ discs closely reproduced previously reported morphological, biochemical, and biomechanical values of human and FP discs. The width/length dimension ratio of the minipig TMJ disc was 1.95 (1.69 for human and 1.94 for FP). The biochemical evaluation revealed, on average per wet weight, 24.3% collagen (22.8% for human and 24.9% for FP); 0.8% glycosaminoglycan (GAG; 0.5% for human and 0.4% for FP); and 0.03% DNA (0.008% for human and 0.02% for FP). Biomechanical testing revealed, on average, compressive relaxation modulus of 50 kPa (37 kPa for human and 32 kPa for FP), compressive instantaneous modulus of 1121 kPa (1315 kPa for human and 1134 kPa for FP), and coefficient of viscosity of 13 MPa·s (9 MPa·s for human and 3 MPa·s for FP) at 20% strain. These properties also varied topographically in accordance to those of human and FP TMJ discs. Anisotropy, quantified by bidirectional tensile testing and histology, again was analogous among minipig, human, and FP TMJ discs. The minipig TMJ's ginglymoarthrodial nature was verified through cone beam computer tomography. Collectively, the similarities between minipig and human TMJ discs support the use of minipig as a relevant model for TMJ research; considering the practical advantages conferred by its growth rate and size, the minipig may be a preferred model over FP. PMID: 28548559

Mandibular odontoameloblastoma in a rat and a horse

Murphy B, Bell C, Koehne A, Dubielzig RR.

Odontoameloblastoma (OA) is a mixed odontogenic tumor that is an ameloblastoma with concurrent histologic evidence of odontoma differentiation. As a mixed tumor, OA is a tripartite lesion comprised of neoplastic odontogenic epithelium, induced dental ectomesenchyme (dental pulp), and mineralized dental matrix. Although rare, OA represents a diagnostic conundrum, as it is histologically closely related to 2 other mixed odontogenic tumors: odontoma (complex and compound) and ameloblastic fibro-odontoma. Herein we describe an OA arising from the mandible of a 4-mo-old Fischer 344 rat that had been exposed in utero to the mutagen ENU (N-ethyl-N-nitrosourea), and a naturally occurring lesion in a 2-y-old Appaloosa horse. In order to satisfy the diagnostic criteria for this lesion, mineralized dental matrix in relationship to neoplastic odontogenic epithelium must be identifiable within the OA lesion. This group of odontogenic tumors is differentiated by the degree to which the dental matrix is organized and the relative proportions of pulp ectomesenchyme, odontogenic matrix, and odontogenic epithelium. PMID: 28545325

ETV1-Positive Cells Give Rise to BRAFV600E -Mutant Gastrointestinal Stromal Tumors

 

Ran L, Murphy D, Sher J, Cao Z, Wang S, Walczak E, Guan Y, Xie Y, Shukla S, Zhan Y, Antonescu CR, Chen Y, Chi P.

Gastrointestinal stromal tumor (GIST) is the most common subtype of sarcoma. Despite clinical advances in the treatment of KIT/PDGFRA-mutant GIST, similar progress against KIT/PDGFRA wild-type GIST, including mutant BRAF-driven tumors, has been limited by a lack of model systems. ETV1 is a master regulator in the intestinal cells of Cajal (ICC), thought to be the cells of origin of GIST. Here, we present a model in which the ETV1 promoter is used to specifically and inducibly drive Cre recombinase in ICC as a strategy to study GIST pathogenesis. Using a conditional allele for BrafV600E , a mutation observed in clinical cases of GIST, we observed that BrafV600E activation was sufficient to drive ICC hyperplasia but not GIST tumorigenesis. In contrast, combining BrafV600E activation with Trp53 loss was sufficient to drive both ICC hyperplasia and formation of multifocal GIST-like tumors in the mouse gastrointestinal tract with 100% penetrance. This mouse model of sporadic GIST model was amenable to therapeutic intervention, and it recapitulated clinical responses to RAF inhibition seen in human GIST. Our work offers a useful in vivo model of human sporadic forms of BRAF-mutant GIST to help unravel its pathogenesis and therapeutic response to novel experimental agents. PMID: 28539323 PMCID: PMC5513719

Detection and prevalence of Haemoproteus archilochus (Haemosporida, Haemoproteidae) in two species of California hummingbirds

 

Bradshaw AC, Tell LA, Ernest HB, Bahan S, Carlson J, Sehgal RNM.

Haemosporidian blood parasites are transmitted to a wide range of avian hosts via blood-sucking dipteran vectors. Microscopy has revealed an impressive diversity of avian haemosporidia with more than 250 species described. Moreover, PCR and subsequent sequence analyses have suggested a much greater diversity of haemosporidia than morphological analyses alone. Given the importance of these parasites, very few studies have focused on the charismatic hummingbirds. To date, three Haemoproteus species (Haemoproteus archilochus, Haemoproteus trochili, and Haemoproteus witti) and one Leucocytozoon species (Leucocytozoon quynzae) have been described in blood samples taken from hummingbirds (Trochilidae). Unconfirmed Plasmodium lineages have also been detected in hummingbirds. Here, we report the detection of H. archilochus in two hummingbird species (Calypte anna and Archilochus alexandri) sampled in Northern California and perform a phylogenetic analysis of mitochondrial cytochrome b (cyt b) gene lineages. A total of 261 hummingbirds (157 C. anna, 104 A. alexandri) were sampled and screened for blood parasites using PCR and microscopy techniques. Combining both methods, 4 (2.55%) haemosporidian infections were detected in C. anna and 18 (17.31%) haemosporidian infections were detected in A. alexandri. Molecular analyses revealed four distinct H. archilocus cyt b lineages, which clustered as a monophyletic clade. No species of Plasmodium or Leucocytozoon were detected in this study, raising the possibility of specific vector associations with hummingbirds. These results provide resources for future studies of haemosporidian prevalence, diversity, and pathogenicity in California hummingbird populations. PMID: 28534106

Impairment of antioxidant mechanisms in Japanese Medaka (Oryzias latipes) by acute exposure to aluminum

 

Ramírez-Duarte WF, Kurobe T, Teh SJ.

Increasing aluminum (Al) concentrations in aquatic habitats as a result of anthropogenic acidification and industrialization is a global issue. Moreover, in extensive areas of the humid tropics and subtropics, high Al concentrations in freshwater are observed because of both naturally low pH and high Al concentrations in soil. Al increases production of reactive oxygen species and enhances oxidative damage in mammals. However, no studies have examined the effect of environmentally relevant concentrations of Al at low pH on oxidative stress in fish. This study assessed Al-induced effects on enzymatic and non-enzymatic antioxidants, lipid peroxidation, and on expression of oxidative stress-related genes at low pH using Japanese Medaka (Oryzias latipes). Larval fish were exposed to dissolved Al concentrations of 0, 1.7, 6.2 and 16.7μgL-1 for 4days at pH5.3 in soft water. Al caused a significant reduction in activity of glutathione peroxidase at 6.2 and 16.7μgL-1, and of glutathione reductase at 16.7μgL-1 in whole body homogenates. No changes were observed in the expression of the glutathione peroxidase gene, and expression levels of the glutathione reductase gene were too low to be quantitated. Even though there was an overall decrease in the activity of catalase and in the concentration of glutathione, differences were not significant compared to the control. Changes in lipid peroxidation were not found. This study showed that exposure to environmentally relevant concentrations of Al at low pH impairs antioxidant defense mechanisms of Medaka. PMID: 28529176

Early life allergen and air pollutant exposures alter longitudinal blood immune profiles in infant rhesus monkeys

 

Crowley CM, Fontaine JH, Gerriets JE, Schelegle ES, Hyde DM, Miller LA.

Early life is a critical period for the progressive establishment of immunity in response to environmental stimuli; the impact of airborne challenges on this process is not well defined. In a longitudinal fashion, we determined the effect of episodic house dust mite (HDM) aerosol and ozone inhalation, both separately and combined, on peripheral blood immune cell phenotypes and cytokine expression from 4 to 25weeks of age in an infant rhesus monkey model of childhood development. Immune profiles in peripheral blood were compared with lung lavage at 25weeks of age. Independent of exposure, peripheral blood cell counts fluctuated with chronologic age of animals, while IFNγ and IL-4 mRNA levels increased over time in a linear fashion. At 12weeks of age, total WBC, lymphocyte numbers, FoxP3 mRNA and IL-12 mRNA were dramatically reduced relative to earlier time points, but increased to a steady state with age. Exposure effects were observed for monocyte numbers, as well as CCR3, FoxP3, and IL-12 mRNA levels in peripheral blood. Significant differences in cell surface marker and cytokine expression were detected following in vitro HDM or PMA/ionomycin stimulation of PBMC isolated from animals exposed to either HDM or ozone. Lavage revealed a mixed immune phenotype of FoxP3, IFNγ and eosinophilia in association with combined HDM plus ozone exposure, which was not observed in blood. Collectively, our findings show that airborne challenges during postnatal development elicit measureable cell and cytokine changes in peripheral blood over time, but exposure-induced immune profiles are not mirrored in the lung. PMID: 28529118

Differential Disease Susceptibilities in Experimentally Reptarenavirus-Infected Boa Constrictors and Ball Pythons

 

Stenglein MD, Sanchez-Migallon Guzman D, Garcia VE, Layton ML, Hoon-Hanks LL, Boback SM, Keel MK, Drazenovich T, Hawkins MG, DeRisi JL.

Inclusion body disease (IBD) is an infectious disease originally described in captive snakes. It has traditionally been diagnosed by the presence of large eosinophilic cytoplasmic inclusions and is associated with neurological, gastrointestinal, and lymphoproliferative disorders. Previously, we identified and established a culture system for a novel lineage of arenaviruses isolated from boa constrictors diagnosed with IBD. Although ample circumstantial evidence suggested that these viruses, now known as reptarenaviruses, cause IBD, there has been no formal demonstration of disease causality since their discovery. We therefore conducted a long-term challenge experiment to test the hypothesis that reptarenaviruses cause IBD. We infected boa constrictors and ball pythons by cardiac injection of purified virus. We monitored the progression of viral growth in tissues, blood, and environmental samples. Infection produced dramatically different disease outcomes in snakes of the two species. Ball pythons infected with Golden Gate virus (GoGV) and with another reptarenavirus displayed severe neurological signs within 2 months, and viral replication was detected only in central nervous system tissues. In contrast, GoGV-infected boa constrictors remained free of clinical signs for 2 years, despite high viral loads and the accumulation of large intracellular inclusions in multiple tissues, including the brain. Inflammation was associated with infection in ball pythons but not in boa constrictors. Thus, reptarenavirus infection produces inclusions and inclusion body disease, although inclusions per se are neither necessarily associated with nor required for disease. Although the natural distribution of reptarenaviruses has yet to be described, the different outcomes of infection may reflect differences in geographical origin. IMPORTANCE New DNA sequencing technologies have made it easier than ever to identify the sequences of microorganisms in diseased tissues, i.e., to identify organisms that appear to cause disease, but to be certain that a candidate pathogen actually causes disease, it is necessary to provide additional evidence of causality. We have done this to demonstrate that reptarenaviruses cause inclusion body disease (IBD), a serious transmissible disease of snakes. We infected boa constrictors and ball pythons with purified reptarenavirus. Ball pythons fell ill within 2 months of infection and displayed signs of neurological disease typical of IBD. In contrast, boa constrictors remained healthy over 2 years, despite high levels of virus throughout their bodies. This difference matches previous reports that pythons are more susceptible to IBD than boas and could reflect the possibility that boas are natural hosts of these viruses in the wild. PMID: 28515291

Evaluation of Weight Change During Carboplatin Therapy in Dogs With Appendicular Osteosarcoma

 

Story AL, Boston SE, Kilkenny JJ, Singh A, Woods JP, Culp WTN, Skorupski KA, Lu X.

BACKGROUND: The prevalence of cancer cachexia in veterinary medicine has not been studied widely, and as of yet, no definitive diagnostic criteria effectively assess this syndrome in veterinary patients. OBJECTIVES: (1) To determine the patterns of weight change in dogs with appendicular osteosarcoma treated with amputation and single-agent carboplatin during the course of adjuvant chemotherapy; and (2) to determine whether postoperative weight change is a negative prognostic indicator for survival time in dogs with osteosarcoma. ANIMALS: Eighty-eight dogs diagnosed with appendicular osteosarcoma. Animals were accrued from 3 veterinary teaching hospitals. METHODS: Retrospective, multi-institutional study. Dogs diagnosed with appendicular osteosarcoma and treated with limb amputation followed by a minimum of 4 doses of single-agent carboplatin were included. Data analyzed in each patient included signalment, tumor site, preoperative serum alkaline phosphatase activity (ALP), and body weight (kg) at each carboplatin treatment. RESULTS: A slight increase in weight occurred over the course of chemotherapy, but this change was not statistically significant. Weight change did not have a significant effect on survival. Institution, patient sex, and serum ALP activity did not have a significant effect on survival. CONCLUSIONS AND CLINICAL IMPORTANCE: Weight change was not a prognostic factor in these dogs, and weight loss alone may not be a suitable method of determining cancer cachexia in dogs with appendicular osteosarcoma. PMID: 28503759 PMCID: PMC5508317

Podocyte-specific soluble epoxide hydrolase deficiency in mice attenuates acute kidney injury

 

Bettaieb A, Koike S, Chahed S, Zhao Y, Bachaalany S, Hashoush N, Graham J, Fatima H, Havel PJ, Gruzdev A, Zeldin DC, Hammock BD, Haj FG.

Podocytes play an important role in maintaining glomerular function, and podocyte injury is a significant component in the pathogenesis of proteinuria. Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose genetic deficiency and pharmacological inhibition have beneficial effects on renal function, but its role in podocytes remains unexplored. The objective of this study was to investigate the contribution of sEH in podocytes to lipopolysaccharide (LPS)-induced kidney injury. We report increased sEH transcript and protein expression in murine podocytes upon LPS challenge. To determine the function of sEH in podocytes in vivo we generated podocyte-specific sEH-deficient (pod-sEHKO) mice. Following LPS challenge, podocyte sEH-deficient mice exhibited lower kidney injury, proteinuria, and blood urea nitrogen concentrations than controls suggestive of preserved renal function. Also, renal mRNA and serum concentrations of inflammatory cytokines IL-6, IL-1β, and TNFα were significantly lower in LPS-treated pod-sEHKO than control mice. Moreover, podocyte sEH deficiency was associated with decreased LPS-induced NF-κB and MAPK activation and attenuated endoplasmic reticulum stress. Furthermore, the protective effects of podocyte sEH deficiency in vivo were recapitulated in E11 murine podocytes treated with a selective sEH pharmacological inhibitor. Altogether, these findings identify sEH in podocytes as a contributor to signaling events in acute renal injury and suggest that sEH inhibition may be of therapeutic value in proteinuria. PMID: 28485854 PMCID: PMC5515292

Colostrum immunoglobulin G concentration of multiparous Jersey cows at first and second milking is associated with parity, colostrum yield, and time of first milking, and can be estimated with Brix refractometry

 

Silva-Del-Río N, Rolle D, García-Muñoz A, Rodríguez-Jiménez S, Valldecabres A, Lago A, Pandey P.

The objective of this study was to evaluate colostrum IgG concentration harvested at first and second milking from multiparous Jersey cows, the dam's lactation number, colostrum yield, and time of first milking. In addition, we validated the use of a Brix refractometer to estimate IgG concentration in colostrum from multiparous Jersey cows using radial immunodiffusion as the reference method. Colostrum samples and total weight of colostrum harvested at first (n = 134) and second (n = 68) milking were collected from 134 multiparous Jersey cows housed in a California herd. Fresh colostrum samples were analyzed for IgG concentration with Brix refractometry and frozen samples by radial immunodiffusion. A total of 90.4 and 42.7% of the samples from first and second milking met industry standards of quality for IgG concentration (>50 g/L). Second and third lactation cows had similar colostrum IgG concentration but lower than cows on their fourth and greater lactation. At second milking, 56.4% of cows on their fourth or greater lactation had colostrum IgG concentrations >50 g/L. When colostrum yield increased from low (<3 kg), medium (3 to 6 kg), to high (>6 kg), IgG concentration decreased. Higher IgG concentration was observed on colostrum harvested at <6 h (short) versus 6 to 11 h (medium) after calving. However, IgG concentration in colostrum harvested after 11 h (long) was similar to that harvested at short and medium time. Readings of %Brix were highly correlated with IgG at first (r = 0.81) and second (r = 0.77) milking. The best Brix threshold to identify colostrum from first milking with >50 IgG g/L was 20.9% based on logit equations with Youden's index criterion and 18.0% based on accuracy criterion. For colostrum harvested at second milking, similar Brix thresholds were obtained, 19.2 and 19.0%, regardless of whether Youden's index or accuracy was used as the selection criterion. Our results indicate that the dam's lactation number, colostrum yield, and time of first milking relative to calving are associated with IgG concentration in colostrum from multiparous Jersey cows. Second milking colostrum from mature Jersey cows should be evaluated to extend colostrum supply on dairies especially during times of shortage. Readings of %Brix can be used to rapidly estimate IgG concentration in Jersey colostrum harvested at first and second milking. PMID: 28478013

Effects of low levels of ultraviolet radiation on antioxidant mechanisms of Japanese Medaka (Oryzias latipes)

 

Ramírez-Duarte WF, Kurobe T, Teh SJ.

Extreme weather events like drought are expected to increase with climate change, which will increase exposure of freshwater fish to ultraviolet (UV) radiation. Compared to fully grown adult fish, fish in early life stages are more susceptible to UV radiation due to the lack of well-developed pigmentation. Even though several studies have described affectation of fish health after exposure to UV radiation, most of the studies have used intensities that are only found on the surface of the earth crust or at shallow depths in water bodies, and little is known about impacts of weaker UV radiation, which can be found in deep water. This study showed effects on the antioxidant system of Japanese Medaka after 7 days of exposure to very low intensities of UV radiation, levels that can be found at deep locations in lakes and rivers. Exposure to UV radiation (UVA: 360.1 ± 18.4 μW cm-2 for a dose of 21.6 ± 1.2 mJ cm-2 min-1, and UVB: 6.3 ± 0.5 μW cm-2 for a dose of 0.38 ± 0.03 mJ cm-2 min-1) caused a reduction in the catalase activity (over 50%) and enhanced oxidative damage to lipids. Results of this study showed that environmentally relevant, low levels of UV radiation affect mechanisms by which fish deal with enhanced production of reactive oxygen species and oxidative damage. The results raise concerns about early life stages of fish under scenarios of increased exposure to solar light, such as in tropic regions or during summer in temperate regions PMID: 28448912

Aquatic Bird Bornavirus-Associated Disease in Free-Living Canada Geese ( Branta canadensis ) in the Northeastern USA

 

Murray M, Guo J, Tizard I, Jennings S, Shivaprasad HL, Payne S, Ellis JC, Van Wettere AJ, O'Brien KM.

During the winter of 2013-14, 22 Canada geese ( Branta canadensis ) were admitted to the Wildlife Clinic at the Cummings School of Veterinary Medicine at Tufts University with nonspecific neurologic abnormalities and emaciation. Five of these geese, along with three geese that were submitted dead, were evaluated via histopathology, immunohistochemistry, and reverse transcription PCR (RT-PCR) for bornaviruses. Histopathologically, six of the eight birds had lymphoplasmacytic encephalitis. One bird, which also had encephalitis, had a dilated esophagus. Lead poisoning, West Nile virus, avian influenza, and avian paramyxovirus infection were excluded from the diagnosis. Brain tissue from all eight geese was positive for bornaviral N-antigen on immunohistochemistry. Frozen brain tissue from five birds was available for bornavirus RT-PCR. Three of the five birds were positive for the bornavirus M gene. Formalin-fixed paraffin-embedded brain tissue was evaluated on the remaining three geese via RT-PCR, with one of these geese testing positive. A bornavirus was subsequently cultured in duck embryo fibroblasts from the brain of one Canada Goose. This virus genome was sequenced, and the virus was identified as aquatic bird bornavirus 1. We were unable to identify any unusual features of this genome that would account for its apparent pathogenicity, given that subclinical infection with bornavirus in waterfowl is common in North America. PMID: 28445657

Rapid Throughput Analysis of GABAA Receptor Subtype Modulators and Blockers Using DiSBAC1(3) Membrane Potential Red Dye

 

Nik AM, Pressly B, Singh V, Antrobus S, Hulsizer S, Rogawski MA, Wulff H, Pessah IN.

Fluorometric imaging plate reader membrane potential dye (FMP-Red-Dye) is a proprietary tool for basic discovery and high-throughput drug screening for G-protein-coupled receptors and ion channels. We optimized and validated this potentiometric probe to assay functional modulators of heterologous expressed GABAA receptor (GABAAR) isoforms (synaptic α1β3γ2, extrasynaptic α4β3δ, and β3 homopentomers). High-resolution mass spectrometry identified FMP-Red-Dye as 5,5'-(1-propen-1-yl-3-ylidene)bis[1,3-dimethyl-2-thio-barbituric acid]. GABAAR-expressing cells equilibrated with FMP-Red-Dye exhibited depolarized equilibrium membrane potentials compared with GABAAR-null cells. The channel blockers picrotoxin, fipronil, and tetramethylenedisulfotetramine, and the competitive antagonist bicuculline reduced fluorescence near the levels in GABAAR-null cells indicating that FMR-Red-Dye, a barbiturate derivative, activates GABAAR-mediated outward Cl- current in the absence of GABA. GABA caused concentration-dependent increases in fluorescence with rank order of potencies among GABAAR isoforms consistent with results from voltage-clamp experiments (EC50 values for α4β3δ, α1β3γ2, and β3 homopentamers were 6 ± 1, 40 ± 11, and >18 mM, respectively), whereas GABAAR-null cells were unresponsive. Neuroactive steroids (NAS) increased fluorescence of GABAAR expressing cells in the absence of GABA and demonstrated positive allosteric modulation in the presence of GABA, whereas benzodiazepines only exhibited positive allosteric modulator (PAM) activity. Of 20 NAS tested, allopregnanolone, (3α,5α,20E)-3-hydroxy-13,24-cyclo-18-norcholan-20-ene-21-carbonitrile, eltanolone, 5β-pregnan-3α,21-diol-20-one, and ganaxolone showed the highest potency. The FMP-Red-Dye-based assay described here provides a sensitive and quantitative method of assessing the activity of GABAAR agonists, antagonists, and PAMs on diverse GABAAR isoforms. The assay has a wide range of applications, including screening for antiseizure agents and identifying channel blockers of interest to insecticide discovery or biosecurity. PMID: 28428226 PMCID: PMC5452057

A missense mutation in damage-specific DNA binding protein 2 is a genetic risk factor for limbal squamous cell carcinoma in horses

 

Bellone RR, Liu J, Petersen JL, Mack M, Singer-Berk M, Drögemüller C, Malvick J, Wallner B, Brem G, Penedo MC, Lassaline M.

Squamous cell carcinoma (SCC) is the most common cancer of the equine eye, frequently originating at the limbus, with the potential to invade the cornea, cause visual impairment, and result in loss of the eye. Several breeds of horses have a high occurrence of limbal SCC implicating a genetic basis for limbal SCC predisposition. Pedigree analysis in the Haflinger breed supports a simple recessive mode of inheritance and a genome-wide association study (N = 23) identified a 1.5 Mb locus on ECA12 significantly associated with limbal SCC (Pcorrected = 0.04). Sequencing the most physiologically relevant gene from this locus, damage specific DNA binding protein 2 (DDB2), identified a missense mutation (c.1013 C > T p.Thr338Met) that was strongly associated with limbal SCC (P = 3.41 × 10-10 ). Genotyping 42 polymorphisms narrowed the ECA12 candidate interval to 483 kb but did not identify another variant that was more strongly associated. DDB2 binds to ultraviolet light damaged DNA and recruits other proteins to perform global genome nucleotide excision repair. Computational modeling predicts this mutation to be deleterious by altering conformation of the β loop involved in photolesion recognition. This DDB2 variant was also detected in two other closely related breeds with reported cases of ocular SCC, the Belgian and the Percheron, suggesting it may also be a SCC risk factor in these breeds. Furthermore, in humans xeroderma pigmentosum complementation group E, a disease characterized by sun sensitivity and increased risk of cutaneous SCC and melanomas, is explained by mutations in DDB2. Cross-species comparison remains to be further evaluated. PMID: 28425625

Preexisting lesions associated with complete diaphyseal fractures of the third metacarpal bone in 12 Thoroughbred racehorses

 

Gray SN, Spriet M, Garcia TC, Uzal FA, Stover SM.

We characterized features of complete diaphyseal fractures of third metacarpal bones in Thoroughbred racehorses. Given that stress fractures are known to occur in the third metacarpal bone, an additional aim was to determine if complete fractures are associated with signs of a preexisting incomplete stress fracture. Bilateral metacarpi from 12 Thoroughbred racehorses euthanized because of complete unilateral metacarpal diaphyseal fracture were examined visually and radiographically. Open, comminuted, transverse or short oblique fractures occurred in the middle of the diaphysis or supracondylar region. Periosteal surface discoloration and bone callus formation contiguous with the fracture line were present in fractured bones. All contralateral intact metacarpi had gross anatomic lesions, and 10 had radiographic abnormalities similar to those observed on fractured metacarpi. Catastrophic metacarpal fractures occurred in racehorses with bilateral evidence of preexisting bone injury. PMID: 28423998

Recruitment, Methods, and Descriptive Results of a Physiologic Assessment of Latino Farmworkers: The California Heat Illness Prevention Study

 

Mitchell DC, Castro J, Armitage TL, Vega-Arroyo AJ, Moyce SC, Tancredi DJ, Bennett DH, Jones JH, Kjellstrom T, Schenker MB.

OBJECTIVE: The California heat illness prevention study (CHIPS) devised methodology and collected physiological data to assess heat related illness (HRI) risk in Latino farmworkers. METHODS: Bilingual researchers monitored HRI across a workshift, recording core temperature, work rate (metabolic equivalents [METs]), and heart rate at minute intervals. Hydration status was assessed by changes in weight and blood osmolality. Personal data loggers and a weather station measured exposure to heat. Interviewer administered questionnaires were used to collect demographic and occupational information.  RESULTS: California farmworkers (n = 588) were assessed. Acceptable quality data was obtained from 80% of participants (core temperature) to 100% of participants (weight change). Workers (8.3%) experienced a core body temperature more than or equal to 38.5 °C and 11.8% experienced dehydration (lost more than 1.5% of body weight). CONCLUSIONS: Methodology is presented for the first comprehensive physiological assessment of HRI risk in California farmworkers. PMID: 28414703 PMCID: PMC5503787

Anaconda paramyxovirus infection in an adult green anaconda after prolonged incubation: Pathological characterization and whole genome sequence analysis

 

Woo PCY, Martelli P, Hui SW, Lau CCY, Groff JM, Fan RYY, Lau SKP, Yuen KY

From July 2011 to June 2012, 31 out of 33 green anaconda juveniles from an oceanarium in Hong Kong died over a 12-month period. These anacondas were progeny of a female anaconda purchased from Japan and added to the collection in May 2011. The juvenile anacondas were born in July 2011. A novel paramyxovirus, named anaconda paramyxovirus (AnaPV), was isolated from these affected juvenile anacondas. In July 2015, one of the remaining two anacondas, that survived the cluster of fatal infections, died at the age of four. Pathologically, both the death of the four-year-old anaconda and the previous deaths of the anaconda juveniles involved multiple, similar organs. However, the organ that was primarily affected in the juvenile anacondas that died in 2011 was the kidney, whereas the most remarkable lesions in the four-year-old anaconda involved the lungs. Granulomas previously observed in the juvenile anacondas with AnaPV infections were not obvious in the four-year-old anaconda. RT-PCR for the L gene of AnaPV was positive for the lungs, kidneys, ovary, spleen, liver, tracheal content and gall bladder of the four-year-old anaconda, with a median viral load of 1.32×106AnaPVRNAcopies/mg. Complete genome sequencing revealed that there were only 12-14 nucleotide changes in the AnaPV genome of the four-year old anaconda compared to those of the AnaPV found in anaconda juveniles in 2011/2012. Among these nucleotide changes, only four were non-synonymous mutations, with one in the N gene, one in the M gene and two in the HN gene. Both epidemiological and molecular data supported that the four-year-old green anaconda probably acquired the AnaPV from its mother or its siblings that died 3-4years ago, and its death is a result of an unprecedented extended incubation period or latency of AnaPV followed by a subsequent manifestation of clinical disease and death. PMID: 28404483

Outcome of laparoscopic adrenalectomy for resection of unilateral noninvasive adrenocortical tumors in 11 cats

 

Mitchell JW, Mayhew PD, Culp WTN, Brad Case J, Singh A, Fuller MC, Della Maggiore A.

OBJECTIVE: To describe the technique and outcomes of laparoscopic adrenalectomy (LA) in cats with adrenocortical neoplasia.

STUDY DESIGN: Retrospective case series. ANIMALS: Eleven client-owned cats with unilateral adrenal tumors.  METHODS: Medical records of cats that underwent LA for unilateral functional adrenal tumors at 3 veterinary teaching hospitals were reviewed. Data collected included signalment, clinical signs, physical examination findings, diagnostic imaging results, preoperative laboratory tests, laparoscopic port placement and techniques, duration of anesthesia and surgery, complications, concomitant procedures, need for conversion to an open celiotomy, histopathological diagnosis, and postoperative survival.  RESULTS:  Eleven cats were included, 5 with right-sided and 6 with left-sided tumors. Tumors were aldosterone-secreting (n = 8), progesterone-secreting (n = 2), or testosterone-secreting (n = 1). Adrenalectomy was successfully performed in all 11 cats although 4 cases required conversion to an open celiotomy, due to poor visualization (n = 2), close adherence of the tumor to the caudal vena cava (n = 1), and inability to maintain adequate pneumoperitoneum (n = 1). Ten of the 11 cats were discharged from the hospital, with a median survival time of 803 days (range 467-1123 days). One cat died from severe pancreatitis and cardiogenic pulmonary edema.  CONCLUSION: Adrenalectomy can be performed in cats via laparoscopy but is technically challenging, and associated with a relatively high conversion rate (36%). PMID: 28390062

A review of potential bluetongue virus vaccine strategies

 

Mayo C, Lee J, Kopanke J, MacLachlan NJ.

Bluetongue (BT) is an economically important, non-zoonotic arboviral disease of certain wild and domestic species of cloven-hooved ungulates. Bluetongue virus (BTV) is the causative agent and the occurrence of BTV infection is distinctly seasonal in temperate regions of the world, and dependent on the presence of vector biting midges (e.g. Culicoides sonorensis in much of North America). In recent years, severe outbreaks have occurred throughout Europe and BTV is endemic in most tropical and temperate regions of the world. Several vaccines have been licensed for commercial use, including modified live (live-attenuated) and inactivated products, and this review summarizes recent strategies developed for BTV vaccines with emphasis on technologies suitable for differentiating naturally infected from vaccinated animals. The goal of this review is to evaluate realistic vaccine strategies that might be utilized to control or prevent future outbreaks of BT. PMID: 28377132

Diagnostic outcome of contrast videofluoroscopic swallowing studies in 216 dysphagic dogs

 

Pollard RE, Marks SL, Cheney DM, Bonadio CM.

Determining the anatomic and functional origin for dysphagia is critical for development of an appropriate therapeutic plan and determination of the prognosis. The purpose of this retrospective study was to report the quantitative and qualitative outcome of contrast videofluoroscopic swallowing studies in a large cohort of dysphagic dogs presenting to a tertiary veterinary care hospital. The videofluoroscopic swallowing studies were reviewed to generate values for pharyngeal constriction ratio, timing of swallowing events (maximum pharyngeal contraction, opening of upper esophageal sphincter, closing of upper esophageal sphincter, and reopening of epiglottis), type of esophageal peristalsis generated, and esophageal transit time. One or more anatomic locations for origin of dysphagia were assigned (pharyngeal, cricopharyngeal, esophageal (primary motility disorder), other esophageal (stricture, vascular ring anomaly, mass), lower esophageal sphincter/hiatus. Sixty-one of 216 studies (28%) were deemed unremarkable. Twenty-seven of 216 dogs (13%) had pharyngeal dysphagia, 17/216 dogs (8%) had cricopharyngeal dysphagia, 98/216 dogs (45%) had dysphagia secondary to esophageal dysmotility, 19/216 dogs (9%) had dysphagia secondary to focal esophageal disorders, and 97/216 dogs (45%) had dysphagia of lower esophageal sphincter/hiatus origin. Multiple abnormalities were present in 82/216 (38%) dogs. Elevated pharyngeal constriction ratio was associated with pharyngeal, cricopharyngeal, and esophageal motility disorders, delayed upper esophageal sphincter opening was associated with cricopharyngeal disorders, a lower percentage of primary esophageal peristaltic waves was associated with cricopharyngeal, pharyngeal, or primary esophageal motility disorders. In conclusion, videofluoroscopic swallowing studies was pivotal in the diagnosis of dysphagia with 155/216 (72%) dogs receiving a final diagnosis. PMID: 28337826

The effect of radiation dose on the onset and progression of radiation-induced brain necrosis in the rat model

 

Hartl BA, Ma HSW, Hansen KS, Perks J, Kent MS, Fragoso RC, Marcu L.

PURPOSE: To provide a comprehensive understanding of how the selection of radiation dose affects the temporal and spatial progression of radiation-induced necrosis in the rat model. MATERIALS AND METHODS: Necrosis was induced with a single fraction of radiation exposure, at doses ranging between 20 and 60 Gy, to the right hemisphere of 8-week-old Fischer rats from a linear accelerator. The development and progression of necrosis in the rats was monitored and quantified every other week with T1- and T2-weighted gadolinium contrast-enhanced MRI studies. RESULTS: The time to onset of necrosis was found to be dose-dependent, but after the initial onset, the necrosis progression rate and total volume generated was constant across different doses ranging between 30 and 60 Gy. Radiation doses less than 30 Gy did not develop necrosis within 33 weeks after treatment, indicating a dose threshold existing between 20 and 30 Gy. CONCLUSION: The highest dose used in this study led to the shortest time to onset of radiation-induced necrosis, while producing comparable disease progression dynamics after the onset. Therefore, for the radiation-induced necrosis rat model using a linear accelerator, the most optimum results were generated from a dose of 60 Gy. PMID: 28306402

Identification of a new Y chromosome haplogroup in Spanish native cattle

 

Pelayo R, Penedo MCT, Valera M, Molina A, Millon L, Ginja C, Royo LJ.

The aim of this work was to perform a thorough analysis of the diversity of Y-haplotypes in Spanish cattle. A total of 207 Bos taurus males were sampled across 25 European breeds, with a special focus on rare, local Spanish populations. Animals were genotyped with five Y-specific microsatellites (INRA189, UMN0103, UMN0307, BM861 and BYM1), two indels (ZFY10 and USP9Y) and one SNP (UTY19). A new haplogroup, distinct from those described by Götherström et al. (2005), was identified and named Y1.2. Samples representing the three B. taurus Y-haplogroups were genotyped for four additional Y chromosome SNPs (rs121919254, rs121919281, rs121919323 and rs137049553). Among these SNPs, only rs121919281 was informative in B. taurus and helped to confirm the new Y1.2 haplogroup. Analysis of a larger dataset of standardized haplotypes for 1507 individuals from 57 populations from Spain, other European countries and Africa showed the new Y1.2 haplogroup to be found exclusively in Spanish breeds. This finding reinforces the importance of local Spanish cattle as reservoirs of genetic diversity as well as the importance of the Iberian Peninsula in the history of cattle. PMID: 28244125

A novel ultrasonographic assisted technique for desmotomy of the palmar/plantar annular ligament in horses

 

Espinosa P, Nieto JE, Snyder JR, Galuppo LD, Katzman SA.

OBJECTIVES: To describe an ultrasound assisted technique for desmotomy of the palmar/plantar annular ligament (PAL), determine its efficacy and intraoperative complications. STUDY DESIGN: Cadaveric and in vivo study. ANIMALS: Cadaveric limbs (n = 12), adult horses (n = 4), and clinical cases (n = 2). METHODS: Ultrasound assisted desmotomy of the palmar/plantar annular ligament (UAD-PAL) was performed in cadaveric limbs and in standing horses with the operated limb placed in a distal limb splint. The procedure was performed under general anesthesia and was followed by tenoscopic examination in 2 clinical cases. A hook knife was developed for the procedure. Complete transection was assessed by postmortem dissection (10 forelimbs, 10 hindlimbs) and tenoscopic examination (1 forelimb, 1 hindlimb). Thickness of PAL, surgery time, other intraoperative parameters and complications associated with the procedure were recorded. RESULTS: Complete PAL transection was accomplished in 20/22 limbs. No iatrogenic damage to adjacent intrathecal structures was identified in any case. The instrument was correctly positioned on the first attempt in 19/22 cases. The most common intraoperative complication was inadvertent subcutaneous placement of the instrument (n = 2). Significant thickening of the PAL (3 mm) was present in 1/2 limbs in which complete transection was not achieved. CONCLUSIONS: UAD-PAL with the custom-made hook knife was effective at transecting the PAL with minimal intraoperative complications. The procedure can be performed in standing sedated horses. Another method should be considered in horses with thickened PAL. PMID: 28186643

Dynamics of Co-Infection with Bartonella henselae Genotypes I and II in Naturally Infected Cats: Implications for Feline Vaccine Development

 

Huwyler C, Heiniger N, Chomel BB, Kim M, Kasten RW, Koehler JE.

Bartonella henselae is an emerging bacterial pathogen causing cat-scratch disease and potentially fatal bacillary angiomatosis in humans. Bacteremic cats constitute a large reservoir for human infection. Although feline vaccination is a potential strategy to prevent human infection, selection of appropriate B. henselae strains is critical for successful vaccine development. Two distinct genotypes of B. henselae (type I, type II) have been identified and are known to co-infect the feline host, but very little is known about the interaction of these two genotypes during co-infection in vivo. To study the in vivo dynamics of type I and type II co-infection, we evaluated three kittens that were naturally flea-infected with both B. henselae type I and type II. Fifty individual bloodstream isolates from each of the cats over multiple time points were molecularly typed (by 16S rRNA gene sequencing), to determine the prevalence of the two genotypes over 2 years of persistent infection. We found that both B. henselae genotypes were transmitted simultaneously to each cat via natural flea infestation, resulting in mixed infection with both genotypes. Although the initial infection was predominately type I, after the first 2 months, the isolated genotype shifted to exclusively type II, which then persisted with a relapsing pattern. Understanding the parameters of protection against both genotypes of B. henselae, and the competitive dynamics in vivo between the two genotypes, will be critical in the development of a successful feline vaccine that can ultimately prevent B. henselae transmission to human contacts. PMID: 28150014

An assessment of direct and indirect effects of two herbicides on aquatic  communities

 

Hasenbein S, Lawler SP, Connon RE.

Herbicides are often detected in watersheds at concentrations that are toxic to phytoplankton, potentially causing indirect effects on higher trophic organisms. The long-term effects of 5 applications over 30 d of binary mixtures of the herbicides diuron and hexazinone were assessed at "low" and "high" concentrations typically found in the environment, using mesocosms. Sixteen of 95 phytoplankton taxa, 3 of 18 zooplankton taxa, and 6 of 14 macroinvertebrate taxa responded negatively to contaminant exposures. Herbicide applications altered the phytoplankton community structure. Relative abundance of Cyanophyceae decreased following 5 applications from 52.1% in the control to 37.3% in the low treatment and to 25.9% in the high treatment, while Chlorophyceae increased to 50.6% in the low treatment and to 61.7% in the high treatment compared with the control (39.7%). Chlorophyceae had the greatest number of affected species (8), whereas 1 species within the Cyanophyceae was negatively affected on more than 1 sampling day. Further, chlorophyll a was reduced on 4 and 5 d out of the 8 total sampling days in the low and high treatments, respectively, compared with the control. These results highlight that integrating multiple taxa and contaminants with long-term exposures in ecological risk assessments of herbicides can facilitate the ability to make predictive and mechanistic generalizations about the role of herbicides in shaping patterns of species abundance in natural systems. PMID: 28106287

Diagnostic approach to catastrophic musculoskeletal injuries in racehorses

 

Diab SS, Stover SM, Carvallo F, Nyaoke AC, Moore J, Hill A, Arthur R, Uzal FA.

Catastrophic musculoskeletal injuries are the most common cause of euthanasia or spontaneous death in racehorses, and the most common cause of jockey falls with potential for serious human injury. Horses are predisposed to the vast majority of these injuries by preexisting lesions that can be prevented by early diagnosis and adequate bone injury management. A thorough examination of the musculoskeletal system in racehorses often determines the cause of these injuries and generates data to develop injury prevention strategies. We describe the diagnostic approach to musculoskeletal injury, review the methodology for the examination of racehorse limbs, and provide anatomy and pathology tools to perform an organized and thorough postmortem examination of the musculoskeletal system in equine athletes. PMID: 28065163

Greater Species Richness of Bacterial Skin Symbionts Better Suppresses the Amphibian Fungal Pathogen Batrachochytrium Dendrobatidis

 

Piovia-Scott J, Rejmanek D, Woodhams DC, Worth SJ, Kenny H McKenzie V, Lawler SP, Foley JE.

The symbiotic microbes that grow in and on many organisms can play important roles in protecting their hosts from pathogen infection. While species diversity has been shown to influence community function in many other natural systems, the question of how species diversity of host-associated symbiotic microbes contributes to pathogen resistance is just beginning to be explored. Understanding diversity effects on pathogen resistance could be particularly helpful in combating the fungal pathogen Batrachochytrium dendrobatidis (Bd) which has caused dramatic population declines in many amphibian species and is a major concern for amphibian conservation. Our study investigates the ability of host-associated bacteria to inhibit the proliferation of Bd when grown in experimentally assembled biofilm communities that differ in species number and composition. Six bacterial species isolated from the skin of Cascades frogs (Rana cascadae) were used to assemble bacterial biofilm communities containing 1, 2, 3, or all 6 bacterial species. Biofilm communities were grown with Bd for 7 days following inoculation. More speciose bacterial communities reduced Bd abundance more effectively. This relationship between bacterial species richness and Bd suppression appeared to be driven by dominance effects-the bacterial species that were most effective at inhibiting Bd dominated multi-species communities-and complementarity: multi-species communities inhibited Bd growth more than monocultures of constituent species. These results underscore the notion that pathogen resistance is an emergent property of microbial communities, a consideration that should be taken into account when designing probiotic treatments to reduce the impacts of infectious disease. PMID: 28064360

Radiographic evaluation in clinical practice of the types and stage of incisor tooth resorption and hypercementosis in horses

 

Henry TJ, Puchalski SM, Arzi B, Kass PH, Verstraete FJM.

BACKGROUND: There are several reports of incisor tooth resorption and hypercementosis in horses but, to date, studies have been limited in case numbers and to advanced lesions. Tooth resorption in other species is a radiographic diagnosis of types of resorption that are often identified before clinical signs. Our goal was to evaluate radiographically incisor tooth resorption in a large population of horses, utilising interpretation criteria from canine and human dentistry. OBJECTIVE: To document and classify incisor tooth resorption and hypercementosis. STUDY DESIGN: Retrospective descriptive case series. METHODS: Horses presented for routine dental care >5 years old were included only if owners were unaware of incisor pathology. Radiographs (three views) were obtained of the incisor teeth and incisor teeth resorption was classified according to the radiographic criteria described for man and dogs. Hypercementosis and its location were recorded. RESULTS: Tooth resorption was detected in 149 of 169 (88.2%) horses and 951 of 1952 (48.7%) of incisor teeth. The classification system used was applicable in 926 (97.2%) of 951 affected teeth. Hypercementosis was detected in 34 (20.1%) horses and 148 (7.6%) teeth. As horses increased in age, resorption and hypercementosis was more frequent; no significant differences were found among sex or breed categories. All horses with hypercementosis had resorption, but only 23.4% of horses with resorption had hypercementosis. Advanced (stage ≥3) resorption was detected in 159 (8.1%) teeth and 54 (32.0%) horses in an otherwise clinically healthy population. MAIN LIMITATIONS: Certain horses' anatomy precluded isolation of the mandibular third incisor teeth from the canine teeth due to superimposition. CONCLUSIONS: Incisor tooth resorption, in particular external replacement resorption and external inflammatory resorption, is common in horses. Hypercementosis is consistently associated with resorption, but the inverse association is inconsistent. PMID: 27862232

Assessment of tear film osmolarity using the TearLab™ osmometer in normal dogs and dogs with keratoconjunctivitis sicca

 

Sebbag L, Park SA2 Kass PH, Maggs DJ, Attar M, Murphy CJ.

OBJECTIVE: To evaluate repeatability and reproducibility of tear osmolarity measured using the TearLab™ osmometer in normal dogs and to assess its diagnostic potential in dogs with keratoconjunctivitis sicca (KCS). ANIMALS STUDIED: Beagle dogs; six normal and five with KCS. PROCEDURES: Tear osmolarity and Schirmer tear test-1 (STT-1) values were obtained at various times. Normal dogs were assessed for diurnal variation and repeatability and reproducibility of measurements. Dogs with KCS were evaluated before and after 5 months' topical twice-daily therapy with 2% cyclosporine.

RESULTS: Mean ± SD tear osmolarity (mOsm/L) was significantly higher in normal dogs (337.4 ± 16.2) than in dogs with KCS before therapy (306.2 ± 18.0; P < 0.0001), but not following therapy with 2% cyclosporine (330.5 ± 13.7; P = 1.00). Osmolarity readings lower than 325.5 mOsm/L were suggestive of KCS (84.8% sensitivity and 87.1% specificity). In normal dogs, tear osmolarity readings were stable during the daytime (P = 0.99). Repeated measurements revealed high variability and typically poor-to-moderate repeatability and reproducibility, although this was improved by taking three successive measurements at each session. Considering combined data from all dogs, a positive correlation existed between STT-1 and tear osmolarity measurements (Pearson's correlation test, P = 0.04, r = 0.62). CONCLUSIONS: Canine tear osmolarity as determined by TearLab™ osmometer was variable, required multiple readings to be informative, and differed from values reported for humans. Dogs with KCS had a lower tear osmolarity than did normal dogs, and this increased following cyclosporine therapy. PMID: 27761982

Pigment retinopathy in warmblood horses with equine degenerative myeloencephalopathy and equine motor neuron disease

 

Finno CJ, Kaese HJ, Miller AD, Gianino G, Divers T, Valberg SJ.

OBJECTIVE: A pigment retinopathy has been reported in adult horses with equine motor neuron disease (EMND) arising from chronic α-tocopherol (α-TP) deficiency. A pigment retinopathy has not been identified in horses with neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) that affects genetically susceptible young horses with α-TP deficiency. The objective of this report is to describe, for the first time, a pigment retinopathy in a family of α-TP-deficient Warmbloods (WB) with clinically apparent NAD/EDM or EMND. ANIMALS AND PROCEDURES: Twenty-five WB horses from one farm underwent complete neurologic and ophthalmic examinations and serum α-TP concentrations were assessed. Two of the most severely ataxic horses were euthanized and postmortem examinations performed.

RESULTS: Alpha-TP deficiency was widespread on this farm (22 of 25 horses). Eleven of 25 horses were clinically normal (age range 2-12 years), one had signs of EMND (6 years of age), 10 had signs of ataxia consistent with NAD/EDM (1-10 years), and two of these were postmortem confirmed concurrent NAD/EDM and EMND. A pigment retinopathy characterized by varying amounts of granular dark pigment in the tapetal retina was observed in four clinically apparent NAD/EDM horses (two postmortem confirmed concurrent NAD/EDM and EMND) and one horse with clinical signs of EMND. CONCLUSIONS: A pigment retinopathy can be present in young α-TP-deficient Warmblood horses with clinical signs of EMND as well as those with signs of NAD/EDM. PMID: 27491953 PMCID: PMC5292316

Risk of obesity in the neutered cat

 

Larsen JA.

Surgical neutering is one of the most common procedures performed on pets in the USA among other countries. There are known effects of neutering on the physiology and behavior of the cat that predispose to obesity, which is the most significant sequela from a nutritional perspective. Increased food intake is the most likely factor influencing weight gain in the neutered cat. Proactively addressing these changes with nutritional management strategies can help prevent weight gain and associated negative consequences. PMID: 27432438

Can a commercially available EPID dosimetry system detect small daily patient setup errors for cranial IMRT/SRS?

 

Hsieh ES, Hansen KS, Kent MS, Saini S, Dieterich S.

PURPOSE: The purpose of this study was to determine if the Sun Nuclear PerFRACTION electronic portal imager device dosimetry software would be able to detect setup errors in a clinical setting and would be able to correctly identify the direction in which the setup error was introduced. METHODS AND MATERIALS: A 7-field intensity modulated radiation therapy (IMRT) treatment plan for a centrally located tumor was developed for 1 phantom and 5 canine cadaver heads. Systematic setup errors were introduced by manually moving the treatment couch by 1, 3, and 5 mm in each translational direction to assess stereotactic radiation surgery (SRS), IMRT, and 3-dimensional (3D) treatment tolerances after the initial alignment was performed. An angular setup error of 5° yaw was also assessed. The delivered treatment fluence was automatically imported in the PerFRACTION software and compared with the baseline fluence. RESULTS: In the canine phantom, a 5-mm shift was undetected by gamma analysis, and up to a 2-cm shift had to be introduced for the gamma pass rate of 3%/3 mm to fall below a 95% pass rate criterion. The same 5-mm shift using 3% difference caused the pass rates for 2 fields to drop below the 95% tolerance. For each respective translational shift, the affected beam angles were consistent across the cadaver heads and correlated with the direction of translational shift. The best field pass rate, worst field pass rate, and average pass rate across all 7 fields was analyzed to develop clinical guidance on parameter settings for SRS, IMRT, and 3D tolerances. CONCLUSIONS: PerFRACTION 2-dimensional mode successfully detected setup errors outside the systematic error tolerance for SRS, IMRT, and 3D when an appropriate analysis metric and pass/fail criteria was implemented. Our data confirm that percent difference may be more sensitive in detecting plan failure than gamma analysis. PMID: 28336480 DOI: 10.1016/j.prro.2016.12.005