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Parkinson’s disease (PD) is a movement disorder characterized by neuroinflammation, α-synuclein pathology, and neurodegeneration. Most cases of PD are non-hereditary, suggesting a strong role for environmental factors, and it has been speculated that disease may originate in peripheral tissues such as the gastrointestinal (GI) tract before affecting the brain. The gut microbiome is altered in PD and may impact motor and GI symptoms as indicated by animal studies, although mechanisms of gut-brain interactions remain incompletely defined. Intestinal bacteria ferment dietary fibers into short-chain fatty acids, with fecal levels of these molecules differing between PD and healthy controls and in mouse models. Among other effects, dietary microbial metabolites can modulate activation of microglia, brain-resident immune cells implicated in PD. We therefore investigated whether a fiber-rich diet influences microglial function in α-synuclein overexpressing (ASO) mice, a preclinical model with PD-like symptoms and pathology. Feeding a prebiotic high-fiber diet attenuates motor deficits and reduces α-synuclein aggregation in the substantia nigra of mice. Concomitantly, the gut microbiome of ASO mice adopts a profile correlated with health upon prebiotic treatment, which also reduces microglial activation. Single-cell RNA-seq analysis of microglia from the substantia nigra and striatum uncovers increased pro-inflammatory signaling and reduced homeostatic responses in ASO mice compared to wild-type counterparts on standard diets. However, prebiotic feeding reverses pathogenic microglial states in ASO mice and promotes expansion of protective disease-associated macrophage (DAM) subsets of microglia. Notably, depletion of microglia using a CSF1R inhibitor eliminates the beneficial effects of prebiotics by restoring motor deficits to ASO mice despite feeding a prebiotic diet. These studies uncover a novel microglia-dependent interaction between diet and motor symptoms in mice, findings that may have implications for neuroinflammation and PD.

While adult neurogenesis is considered to be restricted to the hippocampal dentate gyrus (DG) and the subventricular zone (SVZ), recent studies in humans and rodents provide evidence for newly generated neurons in regions generally considered as non-neurogenic, e.g. the striatum. Stimulating dopaminergic neurotransmission has the potential to enhance adult neurogenesis in the SVZ and the DG most likely via D2/D3 dopamine (DA) receptors. Here, we investigated the effect of two distinct preferential D2/D3 DA agonists, Pramipexole (PPX) and Ropinirole (ROP), on adult neurogenesis in the hippocampus and striatum of adult naïve mice. To determine newly generated cells in the DG incorporating 5-bromo-2'-deoxyuridine (BrdU) a proliferation paradigm was performed in which two BrdU injections (100 mg/kg) were applied intraperitoneally within 12 hours after a 14-day-DA agonist treatment. Interestingly, PPX, but not ROP significantly enhanced the proliferation in the DG by 42% compared to phosphate buffered saline (PBS)-injected control mice. To analyze the proportion of newly generated cells differentiating into mature neurons, we quantified cells co-expressing BrdU and NeuN 32 days after the last of five BrdU injections (50 mg/kg) applied at the beginning of 14-day DA agonist or PBS administration. Again, PPX only enhanced neurogenesis in the DG significantly compared to ROP- and PBS-injected mice. Moreover, we explored the pro-neurogenic effect of both DA agonists in the striatum by quantifying neuroblasts expressing doublecortin (DCX) in the entire striatum, as well as in the dorsal and ventral sub-regions separately. We observed a significantly higher number of DCX+ neuroblasts in the dorsal compared to the ventral sub-region of the striatum in PPX-injected mice. These results suggest that the stimulation of hippocampal and dorsal striatal neurogenesis may be up-regulated by PPX. The increased generation of neural cells, both in constitutively active and quiescent neurogenic niches, might be related to the proportional higher D3 receptor affinity of PPX, non-dopaminergic effects of PPX, or altered motor behavior.

Baculoviruses are commonly used for recombinant protein and vaccine production. Baculoviruses are nonpathogenic to vertebrates, have a large packaging capacity, display broad host and cell type tropism, infect both dividing and nondividing cells, and do not elicit strong immune or allergic responses in vivo. Hence, their use as gene delivery vehicles has become increasingly popular in recent years. Moreover, baculovirus vectors carrying mammalian regulatory elements can efficiently transduce and express transgenes in mammalian cells. Based on the finding that heparan sulfate, which is structurally similar to heparin, is an attachment receptor for baculovirus, we developed a novel scalable baculovirus purification method using heparin-affinity chromatography. Baculovirus supernatants were loaded onto a POROS heparin column, washed to remove unbound materials, and eluted with 1.5 mol/l NaCl, which yielded a recovery of purified baculovirus of 85%. After ultracentrifugation, baculovirus titers increased from 200- to 700-fold with overall yields of 26–29%. We further show that baculovirus particles were infectious, normal in morphology and size, despite high-salt elution and shear forces used during purification and concentration. Our chromatography-based purification method is scalable and, together with ultracentrifugation and/or tangential flow filtration, will be suitable for large-scale manufacturing of baculovirus stocks for protein and vaccine production and in gene therapy applications.

Abstract Background Microglia are considered a major target for modulating neuroinflammatory and neurodegenerative disease processes. Upon activation, microglia secrete inflammatory mediators that contribute to the resolution or to further enhancement of damage in the central nervous system (CNS). Therefore, it is important to study the intracellular pathways that are involved in the expression of the inflammatory mediators. Particularly, the role of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and glycogen synthase kinase-3 (GSK-3) pathways in activated microglia is unclear. Thus, in the present study we investigated the role of Akt and its downstream pathways, GSK-3 and mTOR, in lipopolysaccharide (LPS)-activated primary rat microglia by pharmacological inhibition of these pathways in regard to the expression of cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase-1 (mPGES-1) and to the production of prostaglandin (PG) E2 and PGD2. Findings We show that inhibition of Akt by the Akt inhibitor X enhanced the production of PGE2 and PGD2 without affecting the expression of COX-2, mPGES-1, mPGES-2 and cytosolic prostaglandin E synthase (cPGES). Moreover, inhibition of GSK-3 reduced the expression of both COX-2 and mPGES-1. In contrast, the mTOR inhibitor rapamycin enhanced both COX-2 and mPGES-1 immunoreactivity and the release of PGE2 and PGD2. Interestingly, NVP-BEZ235, a dual PI3K/mTOR inhibitor, enhanced COX-2 and reduced mPGES-1 immunoreactivity, albeit PGE2 and PGD2 levels were enhanced in LPS-stimulated microglia. However, this compound also increased PGE2 in non-stimulated microglia. Conclusion Taken together, we demonstrate that blockade of mTOR and/or PI3K/Akt enhances prostanoid production and that PI3K/Akt, GSK-3 and mTOR differently regulate the expression of mPGES-1 and COX-2 in activated primary microglia. Therefore, these pathways are potential targets for the development of novel strategies to modulate neuroinflammation.

Abstract Background Recent studies suggest an important role for neurotransmitters as modulators of inflammation. Neuroinflammatory mediators such as cytokines and molecules of the arachidonic acid pathway are generated and released by microglia. The monoamine norepinephrine reduces the production of cytokines by activated microglia in vitro. However, little is known about the effects of norepinephrine on prostanoid synthesis. In the present study, we investigate the role of norepinephrine on cyclooxygenase- (COX-)2 expression/synthesis and prostaglandin (PG)E2 production in rat primary microglia. Results Interestingly, norepinephrine increased COX-2 mRNA, but not protein expression. Norepinephrine strongly enhanced COX-2 expression and PGE2 production induced by lipopolysaccharide (LPS). This effect is likely to be mediated by β-adrenoreceptors, since β-, but not α-adrenoreceptor agonists produced similar results. Furthermore, β-adrenoreceptor antagonists blocked the enhancement of COX-2 levels induced by norepinephrine and β-adrenoreceptor agonists. Conclusions Considering that PGE2 displays different roles in neuroinflammatory and neurodegenerative disorders, norepinephrine may play an important function in the modulation of these processes in pathophysiological conditions.

Background: There is no clear genetic cause for most cases of late‐onset Alzheimer's disease (AD), however, genome‐wide association studies have identified multiple genetic variants associated with increased risk of AD. These AD‐risk variants are often located in non‐coding DNA regulatory regions called enhancers, which upon transcription factor binding, modulate the expression of nearby genes. One of the major challenges facing the field of AD research is the assignment of cell‐type specificity and functionality to these genetic variants. Method: Nuclei of microglia, neurons, astrocytes and oligodendrocytes were isolated from frozen human cortical tissue. Sorted nuclei were processed using chromatin immunoprecipitation and sequencing (ChIP‐seq) to define cell type promoter and enhancer regions. The assay for transposase accessible chromatin sequencing (ATAC‐seq) was used to define open chromatin regions, which indicates likely transcription factor binding sites. Proximity Ligation‐Assisted ChIP‐seq (PLAC‐seq) is a chromatin conformation assay that was used to link distal enhancers to target genes. Enhancers were validated by CRISPR‐mediated deletion of putative regions in induce‐pluripotent stem cells (iPSCs) that were derived into neurons, microglia and astrocytes followed by gene expression analysis. Result: Genetic variants associated with increased risk of AD were largely confined to microglia enhancers, whereas genetic variants for psychiatric disorders such as autism and schizophrenia were enriched in neuronal enhancers. Enhancer‐promoter interactome maps connected disease‐risk variants located in enhancers to gene promoters. Integrative analysis of promoter‐enhancer interactome maps has not only revised and expanded the gene repertoire influenced by AD‐risk variants but has also revealed the probable cell types in which they function. Lastly, the BIN1 locus, the second highest putative AD‐risk gene after APOE, has a microglia‐specific enhancer that harbors AD‐risk variants. CRISPR‐deletion of the microglia BIN1 enhancer in iPSCs ablated BIN1 gene expression in iPSC‐derived microglia and not neurons or astrocytes. Conclusion: There has been intense interest in elucidating mechanisms that link human non‐coding genetic variation to risk of neurodegenerative and psychiatric diseases. Towards this effort, enhancer‐promoter connectivity maps in the human brain has enabled an initial cell‐type‐specific interpretation of human genetic variation associated with disease risk for AD and other brain disorders. [ABSTRACT FROM AUTHOR]

Background: Improvement in treatment for patients with recurrent ovarian cancer is needed. Standard therapy in patients with platinum-sensitive recurrent ovarian cancer consists of platinum-based chemotherapy. Median overall survival is reported between 18 and 35 months. Currently, the role of surgery in recurrent ovarian cancer is not clear. In selective patients a survival benefit up to 62 months is reported for patients undergoing complete secondary cytoreductive surgery. Whether cytoreductive surgery in recurrent platinum-sensitive ovarian cancer is beneficial remains questionable due to the lack of level I-II evidence.Methods/design: Multicentre randomized controlled trial, including all nine gynecologic oncologic centres in the Netherlands and their affiliated hospitals. Eligible patients are women, with first recurrence of FIGO stage Ic-IV platinum-sensitive epithelial ovarian cancer, primary peritoneal cancer or fallopian tube cancer, who meet the inclusion criteria. Participants are randomized between the standard treatment consisting of at least six cycles of intravenous platinum based chemotherapy and the experimental treatment which consists of secondary cytoreductive surgery followed by at least six cycles of intravenous platinum based chemotherapy. Primary outcome measure is progression free survival. In total 230 patients will be randomized. Data will be analysed according to intention to treat.Discussion: Where the role of cytoreductive surgery is widely accepted in the initial treatment of ovarian cancer, its value in recurrent platinum-sensitive epithelial ovarian cancer has not been established so far. A better understanding of the benefits and patients selection criteria for secondary cytoreductive surgery has to be obtained. Therefore the 4th ovarian cancer consensus conference in 2010 stated that randomized controlled phase 3 trials evaluating the role of surgery in platinum-sensitive recurrent epithelial ovarian cancer are urgently needed. We present a recently started multicentre randomized controlled trial that will investigate the role of secondary cytoreductive surgery followed by chemotherapy will improve progression free survival in selected patients with first recurrence of platinum-sensitive epithelial ovarian cancer. [ABSTRACT FROM AUTHOR]

Abstract Background The hematopoietic Granulocyte-Colony Stimulating Factor (G-CSF) plays a crucial role in controlling the number of neutrophil progenitor cells. Its function is mediated via the G-CSF receptor, which was recently found to be expressed also in the central nervous system. In addition, G-CSF provided neuroprotection in models of neuronal cell death. Here we used the retinal ganglion cell (RGC) axotomy model to compare effects of local and systemic application of neuroprotective molecules. Results We found that the G-CSF receptor is robustly expressed by RGCs in vivo and in vitro. We thus evaluated G-CSF as a neuroprotectant for RGCs and found a dose-dependent neuroprotective effect of G-CSF on axotomized RGCs when given subcutaneously. As stem stell mobilization had previously been discussed as a possible contributor to the neuroprotective effects of G-CSF, we compared the local treatment of RGCs by injection of G-CSF into the vitreous body with systemic delivery by subcutaneous application. Both routes of application reduced retinal ganglion cell death to a comparable extent. Moreover, G-CSF enhanced the survival of immunopurified RGCs in vitro. Conclusion We thus show that G-CSF neuroprotection is at least partially independent of potential systemic effects and provide further evidence that the clinically applicable G-CSF could become a treatment option for both neurodegenerative diseases and glaucoma.

The presence of HIV in sequestered reservoirs is a central impediment to a functional cure, allowing HIV to persist despite life-long antiretroviral therapy (ART), and driving a variety of comorbid conditions. Our understanding of the latent HIV reservoir in the central nervous system is incomplete, because of difficulties in accessing human central nervous system tissues. Microglia contribute to HIV reservoirs, but the molecular phenotype of HIV-infected microglia is poorly understood. We leveraged the unique "Last Gift" rapid autopsy program, in which people with HIV are closely followed until days or even hours before death. Microglial populations were heterogeneous regarding their gene expression profiles but showed similar chromatin accessibility landscapes. Despite ART, we detected occasional microglia containing cell-associated HIV RNA and HIV DNA integrated into open regions of the host's genome (∼0.005%). Microglia with detectable HIV RNA showed an inflammatory phenotype. These results demonstrate a distinct myeloid cell reservoir in the brains of people with HIV despite suppressive ART. Strategies for curing HIV and neurocognitive impairment will need to consider the myeloid compartment to be successful., (© 2024 Schlachetzki et al.)

The expanding number of specialized oncology therapeutics available in veterinary oncology can make staying updated on the most recent advances challenging. This article summarizes the mechanism of action, available supporting data, and clinical use of three key veterinary cancer/supportive care therapeutics: Laverdia-CA1, Canalevia-CA1, and Stelfonta. This information will help guide clinical use within your practice and can be incorporated into discussions with clients regarding the newest available options for their dogs with cancer., Competing Interests: Disclosure C. Mullin: No disclosures to report. C.A. Clifford: Speaker, advisory board member and consultant with Jaguar Animal Health and Anivive. C.M. Johannes: Speaker, advisory board member and consultant with QBiotics Group; advisory board member with Jaguar Animal Health., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: To retrospectively assess the biological response in cats with pancreatic carcinoma treated with toceranib phosphate., Animals: Twenty-six client-owned cats., Procedure: Patient information from multiple institutions was solicited via an emailed REDCap survey. For inclusion, cats were required to have a confirmed diagnosis of exocrine pancreatic carcinoma either by histopathology, cytology, or both; to have received treatment with toceranib phosphate; and to have adequate follow-up data for analysis., Results: Twenty cats were treated for gross disease and 6 for microscopic disease/incomplete margins. Clinical benefit (complete response, partial response, or stable disease ≥ 10 wk) was observed in 9/20 cats treated in the gross disease setting (45%; complete response: n = 1, stable disease: n = 8). The remaining 11 cats with gross disease did not respond to toceranib phosphate. In the cats with microscopic disease, response was mixed. The median survival time for all cats was 97 d (range: 1 to 1666 d)., Conclusion: Toceranib phosphate was well-tolerated and provided modest clinical benefit to a subset of cats treated., Clinical Relevance: Although feline exocrine pancreatic carcinoma continues to be a challenging disease to treat, toceranib phosphate appeared to provide potential clinical benefit., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Canine splenic hemangiosarcoma (HSA) is an aggressive tumor with a short overall survival time (OST) despite treatment with splenectomy and adjuvant doxorubicin. Modulation of the immune system has been shown to be effective for a variety of human tumors, and may be effective for canine tumors, including HSA. Immunocidin® is a non-specific immunotherapy based on a mycobacterial cell wall fraction. Preliminary work suggests Immunocidin® is safe to give intravenously (IV) in tumor-bearing dogs. This work aimed to evaluate the safety of doxorubicin and Immunocidin® combination in dogs with naturally occurring splenic HSA. A secondary aim of this study was to collect preliminary efficacy data to support a subsequent comprehensive, prospective clinical trial in canine patients with HSA, if the combination of doxorubicin and Immunocidin® was found to be safe. Eighteen dogs with stage II-III splenic HSA were recruited to receive 5 doses of sequential IV doxorubicin and Immunocidin® at two-week intervals following splenectomy. Adverse events (AEs) were graded according to the Veterinary Cooperative Oncology Group v1.1 (VCOG) scheme. Overall survival time was calculated from the date of splenectomy to date of death or loss to follow-up. AEs during administration were infrequent, the most common being hypertension. One patient developed limb and facial twitching and was removed from the study. After infusion, common AEs included lethargy, hyporexia, and diarrhea. One patient developed VCOG grade 5 diarrhea, thrombocytopenia, and anemia. Modifications in the treatment regimen were made to prevent these signs in subsequent patients. The median OST in dogs treated with the combination therapy was estimated at 147 days (range: 39-668 days). Although generally safe, the combination of doxorubicin and Immunocidin® appeared to cause more gastrointestinal effects than doxorubicin alone, and no apparent improvement in OST was noted in this population of dogs., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Musser et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The American Association of Veterinary Clinicians (AAVC) convened a Diversity, Equity, and Inclusivity working group in March 2021 to address the limited diversity (including but not limited to ethnic, racial, and cultural diversity) in clinical post-DVM graduate training programs and academic faculty. Concurrent with a working group formation, the AAVC developed a strategic plan. The central mission of the AAVC is to develop, support, and connect academic leaders to fuel the future of the veterinary medical profession. House officers and their training programs are central to all goals outlined in the strategic plan. Amongst other strategic goals, the working group identified best practices for intern and resident recruitment and selection. We report herein from the current health profession literature ways to identify and recruit talented, diverse candidates especially those with non-traditional (atypical) preparation and experience. We also provide recommendations on best practices for intern and resident selection. This document highlights holistic approaches, some of which are incrementally being incorporated into the Veterinary Intern Resident Matching Program application, that emphasize diversity as a selection criteria for intern and resident selection an important step towards building a more resilient and inclusive workforce. These include expanding candidate assessment beyond grades and class rank into a more standardized method for screening candidates that includes consideration of life experiences and talents outside of veterinary medicine.

Background: Canine peripheral nodal T-cell lymphoma is considered chemotherapy resistant and carries a relatively poor prognosis. Prospective evaluations reporting the impact of chemotherapy on progression-free survival (PFS) and overall survival time for dogs with T-cell lymphoma are lacking. This study examined the impact of L-CHOP (L-asparaginase, doxorubicin, cyclophosphamide, vincristine, prednisone) chemotherapy or L-CHOP in combination with AT-005, a US Department of Agriculture-licensed caninised monoclonal antibody, on PFS and response rates in dogs with clinical intermediate- and high-grade peripheral nodal T-cell lymphoma., Methods: A prospective, randomised, placebo-controlled, investigator- and owner-blinded, multicentre study was completed. All dogs received a 19-week L-CHOP chemotherapy protocol with randomisation (1:1) into placebo or AT-005 groups. Response was evaluated via the Veterinary Cooperative Oncology Group criteria for canine lymphoma., Results: Forty-nine dogs were enrolled (25 received placebo and 24 received AT-005). Most demographic factors were similar between the two groups, with the exception that more dogs with stage IV and V disease were treated with AT-005 (34% vs. 8%; p = 0.03). Median PFS was 103 days (95% confidence interval [CI], 56-118) in the placebo group versus 64 days (95% CI, 36-118) in the AT-005 group. The overall response rate (ORR) for all dogs was 98% (48 of 49); complete response rate in the placebo group (64%) was not different from the AT-005 group (67%)., Conclusions: To the best of the authors' knowledge, this is the first prospective study to document that treatment with L-CHOP chemotherapy, with or without AT-005, may result in a high ORR, but relatively brief PFS in dogs with clinical intermediate- and high-grade T-cell lymphoma., Competing Interests: Chad Johannes, Laura Treml and Lydia Cook McAnulty are former employees of Aratana Therapeutics, Inc. and were employed by Aratana Therapeutics, Inc. during the study period. Elizabeth McNiel is a former employee of Elanco Animal Health. Chad Johannes, Craig Clifford and Philip Bergman are advisory board members for Elanco Animal Health and receive honoraria. Margaret Musser has not declared any conflicts of interest., (© 2022 The Authors. Veterinary Record Open published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

Objective: To determine if dogs with neoplasia produce more coated platelets, a subpopulation of activated platelets generated by dual stimulation with thrombin and convulxin, a glycoprotein VI agonist, than healthy control dogs., Animals: Client-owned dogs diagnosed with lymphoma (n = 19) or solid tumors (14) and healthy control dogs (14)., Procedures: Platelets were stimulated ex vivo with thrombin and convulxin. Flow cytometry was used to quantify the percentage of coated platelets based on high levels of surface fibrinogen. To compare the percentage of coated platelets between the three groups, an ANOVA was performed followed by pairwise 95% confidence intervals (CI) adjusted for multiple comparisons using Tukey's method., Results: We observed a greater mean percentage of coated platelets in dogs with solid tumors, compared with healthy control dogs, by 10.9 percentage points (95% CI: -1.0, 22.8), and a mean percentage of coated platelets in dogs with lymphoma that was less than healthy control dogs by 0.3 percentage points (95% CI: -11.4, 10.8)., Clinical Relevance: This study provides the first data-based evidence that dogs with solid tumors may have a greater mean coated platelet percentage when compared with healthy control dogs, although there is overlap between groups. Further studies are needed investigating coated platelets in specific subsets of neoplasia and investigating additional mechanisms of hypercoagulability in dogs with neoplasia.

Canine lymphoma (LSA) is a diverse, aggressive malignancy initiated by a variety of factors. Understanding those factors could help identify potential treatment options. Chronic inflammation drives lymphoma in human medicine and is suspected to play a role in veterinary medicine. The exact mechanisms, however, have not been elucidated. Upregulation of the cyclooxygenase enzymes, and subsequently prostaglandins, potentially play a stimulatory role. Prostaglandins work through one of four EP receptors (EP1-EP4) and the effects mediated through EP4R specifically are thought to be the primary drivers of cancer development. In human T-cell LSA, overexpression of EP4R has been found and appears to protect LSA cells from apoptosis. The role of EP4R in human B-cell LSA is more nuanced. This study aims to evaluate the mRNA expression of the EP4R gene (ptger4) in canine B-cell and T-cell LSA. Archived canine lymph nodes with histologically confirmed B-cell and T-cell LSA, and reactive lymph nodes, were evaluated for EP4R mRNA expression using a novel RNA in situ hybridization technique (RNAscope). Quantification of RNAscope signals was completed with an advanced digital pathology image analysis system (HALO). Results were reported as copy number, H-score, and percent tumour cell expression of EP4R mRNA. All reactive, B-cell LSA, and T-cell LSA lymph nodes expressed EP4R mRNA. The mRNA copy number, H-score, and percent tumour cell expression of EP4R were higher in B-cell (p < .003) and T-cell (p < .001) LSA samples compared to reactive lymph node samples. There were no differences between B-cell LSA and T-cell LSA., (© 2021 The Authors. Veterinary and Comparative Oncology published by John Wiley & Sons Ltd.)

Background: Insulinomas are the most common tumour of the endocrine pancreas in dogs. These malignant tumours have a high metastatic rate and limited chemotherapeutic options. The multi-receptor tyrosine kinase inhibitor sunitinib malate has benefit in the treatment of metastatic insulinoma in people. Toceranib phosphate, an analogous veterinary agent, may provide benefit for dogs., Methods: A retrospective study describing the extent and duration of clinical outcomes and adverse events (AEs) in dogs diagnosed with insulinoma and receiving toceranib., Results: Records for 30 dogs diagnosed with insulinoma and having received toceranib were identified from a medical record search of five university and eight referral hospitals. The median progression-free interval and overall survival time were 561 days (95% confidence interval (CI): [246, 727 days]) and 656 days (95% CI: [310, 1045 days]), respectively. Of the dogs for which the canine Response evaluation criteria for solid tumours tool could be applied, the majority (66.7%) showed either a complete response, partial response or stable disease. Time to clinical progression was associated with prior intervention and type of veterinary practice. Larger dogs were at increased risk for disease progression and death. No novel AEs were reported., Conclusions: Most dogs diagnosed with insulinoma and receiving toceranib appeared to have a clinical benefit. Randomised, prospective studies are needed to better elucidate and objectively quantify the potential effect and survival benefit of toceranib therapy for management of insulinoma in dogs., Competing Interests: The authors declare they have no conflicts of interest., (© 2022 The Authors. Veterinary Record Open published by John Wiley & Sons Ltd on behalf of British Veterinary Association.)

Background: Despite multiple reports of chemotherapy overdoses (ODs) in human and veterinary medicine, anthracycline ODs have been described infrequently., Hypothesis/objectives: Describe toxicities, treatments, and overall outcome after anthracycline OD in dogs., Animals: Twelve mitoxantrone (MTX) and 4 doxorubicin (DOX) ODs were evaluated., Methods: Multicenter retrospective analysis. The American College of Veterinary Internal Medicine oncology and internal medicine listservs were solicited for cases in which a chemotherapy OD occurred., Results: Sixteen anthracycline cases were collected. Anthracycline ODs occurred because of an error in chemotherapy preparation (n = 9), or dose miscalculation (n = 7). The overall median OD was 1.9× (range, 1.4-10×) the prescribed amount. Most ODs were identified immediately after drug administration (n = 11), and the majority of patients were hospitalized on supportive care (n = 11) for an average of 8 days (range, 3-34 days). Adverse events after the OD included neutropenia (94%), thrombocytopenia (88%), anemia (63%), diarrhea (63%), anorexia (56%), vomiting (38%), lethargy (31%), and nausea (25%). Two patients did not survive the OD. High grade neutropenia was common and did not appear to be mitigated by the administration of filgrastim., Conclusions and Clinical Importance: All patients received supportive care after identifying the OD and death was uncommon. Further evaluation is needed to determine ideal therapeutic guidelines anthracycline OD., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Chemotherapy overdoses (ODs) are severe complications that can occur following the use of antineoplastics. However, little is known about chemotherapy ODs in veterinary medicine. The goals of this retrospective study were to report the occurrence, type, and cause of known chemotherapy ODs in companion animal medicine. The American College of Veterinary Internal Medicine oncology and internal medicine listservs were solicited for chemotherapy OD cases in dogs and cats. An OD was defined as administration of a chemotherapy dose 10% higher than intended, or at a shorter interval than planned. Twelve non-anthracycline ODs in 11 dogs, and 3 cat ODs, were collected. Overdoses in dogs included carboplatin, cyclophosphamide, L-asparaginase, lomustine, mustargen, vincristine, and vinorelbine. The cat ODs included doxorubicin and vincristine. In dogs, the median OD was 2.1x (range: 1.2-10x) the intended dose. All dogs survived the OD and developed a variety of gastrointestinal and hematologic toxicities of varying grades. Both cats with a 2.4x vincristine OD died despite supportive care. The cat who received a 2x OD of doxorubicin survived the event, experiencing Veterinary Cooperative Oncology Group-common terminology criteria for adverse events (VCOG) grade I thrombocytopenia and anemia, and VCOG grade II neutropenia. Chemotherapy ODs appear to be rare in veterinary medicine and are typically 2-3xs the intended dose. Clinical effects include VCOG grade I and II gastrointestinal distress and VCOG grade III and IV hematologic effects. With appropriate supportive care, most patients will survive the event. Life-threatening events are more common in cats following vincristine ODs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Musser, Curran, Flesner and Johannes.)

Canine high-grade mast cell tumours (HGMCT) are associated with a poor prognosis, are inherently more invasive, and have higher rates of local recurrence. The primary aim of this retrospective study was to assess the efficacy of intratumoural tigilanol tiglate (TT) as a local treatment option. Eighteen dogs with mast cell tumours (MCT) cytologically diagnosed by veterinary pathologists as either high-grade or suspected high-grade MCT were treated with TT. The TT dose was based on tumour volume (0.5 mg TT/cm 3 tumour volume) and delivered intratumourally using a Luer lock syringe and a fanning technique to maximise distribution throughout the tumour mass. Efficacy was assessed on the presence/absence of a complete response (CR) to therapy at days 28 and 84 using response evaluation criteria in solid tumours (RECIST). For dogs not achieving a CR after 28 days, the protocol was repeated with a second intratumoural TT injection. Ten out of 18 dogs (56%) in this study achieved and maintained a CR to at least 84 days after their first or second treatment. Six patients were alive and available for evaluation at 2 years, three of those were recurrence free, and a further three patients were recurrence free following a second treatment cycle. Tigilanol tiglate shows efficacy for local treatment of HGMCT, with higher efficacy noted with a second injection if a CR was not achieved following the first treatment. In the event of treatment site recurrence (TSR), the tumour may be controlled with additional treatment cycles. Tigilanol tiglate provides an alternative local treatment approach to dogs with HGMCT that would either pose an unacceptable anaesthetic risk or the tumour location provides a challenge when attempting surgical excision., Competing Interests: GB, JC, PJ, TD, and PR are employed by QBiotics Group Limited and the remaining author, CJ, receives payment by them as an independent consultant. This work was funded by QBiotics and they own the intellectual property and patents associated with tigilanol tiglate., (Copyright © 2021 Brown, Campbell, Jones, De Ridder, Reddell and Johannes.)

Background: Canine pancreatic carcinoma is a rare, aggressive tumour that is often diagnosed late in the course of disease. Effective treatment strategies have been elusive, and overall survival time is short. In humans, treatment with tyrosine kinase inhibitors alone, or in combination with IV gemcitabine, have been moderately effective. As canine and human pancreatic carcinomas share many clinical aspects, strategies that mimic human treatment regimens may confer a better outcome in canine patients. The aim of this study was to assess the role of the veterinary tyrosine kinase inhibitor, toceranib phosphate, in the treatment of cytologically or histologically confirmed canine pancreatic carcinomas., Results: Retrospectively, medical records of dogs with confirmed pancreatic carcinoma treated with toceranib were reviewed. Eight dogs were identified that fit the inclusion criteria. Toceranib was well-tolerated by all patients. Six were treated in the gross disease setting. Four had image-based evaluation of clinical benefit (complete response, partial response, or stable disease of > 10 weeks). Of those patients, 1 achieved a partial response, 2 stable disease, and 1 had progressive disease, for an overall clinical benefit rate of 75 %. An additional dog had clinically stable disease that was not confirmed via imaging. The toceranib-specific median overall survival time was 89.5 days (range: 14-506 days)., Conclusions: Although limited in patient number, this small study suggests that toceranib may have biologic activity in dogs with pancreatic carcinoma. Larger, prospective studies are needed to confirm these preliminary results and define the use of toceranib in the microscopic disease setting., (© 2021. The Author(s).)

Objective: To evaluate survival times for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone., Animals: 109 client-owned dogs recruited from 15 institutions in the United States., Procedures: Dogs were treated with prednisone at a dosage of 40 mg/m 2 , PO, once daily for 7 days and at a dosage of 20 mg/m 2 , PO, once daily thereafter. Quality of life (QOL) was assessed by owners with a visual analog scale when treatment was started (day 0), 1 and 2 weeks after treatment was started, and every 4 weeks thereafter. The primary outcome of interest was survival time as determined by the Kaplan-Meier method. Factors potentially associated with survival time were examined., Results: Median overall survival time was 50 days (95% CI, 41 to 59 days). Factors associated with survival time included substage (a vs b) and immunophenotype (B cell vs T cell). Owner-assigned QOL scores on days 0 and 14 were significantly positively correlated with survival time. When QOL score was dichotomized, dogs with day 0 or day 14 QOL scores ≥ 50 had significantly longer survival times, compared with dogs with day 0 or day 14 QOL scores < 50. No variables were predictive of long-term (> 120 days) survival., Conclusions and Clinical Relevance: Results suggested that survival times were short for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone. Owner-perceived QOL and clinician-assigned substage were both associated with survival time. Findings provide potentially important information for clinicians to discuss with owners of dogs with lymphoma at the time treatment decisions are made.

Canine osteosarcoma (OSA) is an aggressive bone tumour in dogs. Standard-of-care treatment typically results in relatively short survival times; thus, alternative treatments are needed to confer a survival advantage. It has been shown that OSA is an immunogenic tumour, suggesting that immune modulation may result in superior outcomes. A cryopreserved, Listeria-based OSA vaccine was recently developed and an initial study in dogs reported prolonged survival for patients receiving the vaccine in conjunction with standard-of-care. The goal of the current observational study was to report on the safety of the lyophilized formulation of this vaccine (the canine OSA vaccine, live Listeria vector [COV-LLV]) in a group of dogs previously diagnosed with OSA. Forty-nine (49) dogs received the COV-LLV and were included for analysis. Adverse events (AEs) noted during and after vaccinations were recorded. The AEs observed were typically mild and self-limiting, with nausea, lethargy and fever being most common. Four dogs (8%) cultured positive for Listeria (three infections including an amputation site abscess, septic stifle joint and bacterial cystitis; and one dog whose lungs cultured Listeria-positive on necropsy within 24 hours of COV-LLV administration). These cases join the previously reported Listeria-positive thoracic abscess that developed in a canine following use of COV-LLV. Although uncommon, it is important to realize this clinically significant AE is possible in patients treated with live therapeutic Listeria vaccines. As Listeria is zoonotic, caution is required not only for the patient receiving the vaccine, but also for the health care workers and family caring for the patient., (© 2020 The Authors. Veterinary and Comparative Oncology published by John Wiley & Sons Ltd.)

Aortic body tumors, specifically chemodectomas, are the second most common type of canine cardiac tumor; however, information about treatment is currently lacking. This study included dogs with a presumptive or definitive diagnosis of an aortic body chemodectoma that underwent treatment with toceranib phosphate. Cases were solicited via the American College of Veterinary Internal Medicine Cardiology, Internal Medicine, and Oncology listservs using an electronic survey. Cox multivariate analysis of factors potentially impacting survival time was completed. Twenty-seven (27) cases were included in analysis. The clinical benefit rate (complete remission, partial remission, or stable disease >10 weeks) was 89%. A median survival time of 478 days was found for those receiving toceranib alone ( n = 14), which was not statistically different from those treated with additional modalities (521 days). No factors evaluated statistically impacted outcome. Further, prospective studies are warranted to evaluate the use of toceranib for the treatment of canine aortic body chemodectomas., Competing Interests: CJ is a former employee of Pfizer Animal Health. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Coto, Musser, Tropf, Ward, Seo, Mochel and Johannes.)

In many human cancers, the expression of the prostaglandin receptor EP4 (EP4R) is associated with the development of malignancy and a poor prognosis. The expression of EP4R has not yet been evaluated in canine tumors. The objective of this study was to characterize the messenger RNA (mRNA) expression of EP4R in canine osteosarcoma (OSA). Gene expression of EP4R was evaluated using RNA in-situ hybridization (RNAscope). In all canine OSA samples evaluated, strong universal positive expression of EP4R was identified. Gene expression was significantly higher in OSA tissue samples than in normal nasal turbinate bone, possibly implicating EP4R in the pathogenesis of canine OSA., Competing Interests: Conflict of interest: Margaret L. Musser and Chad M. Johannes receive funding from Elanco for clinical studies investigating the use of grapiprant., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Background: Tigilanol tiglate (TT) is a novel small molecule for intratumoral treatment of nonmetastatic mast cell tumors (MCTs) in dogs. In a randomized controlled clinical study, 75% of dogs that received a single TT treatment achieved complete resolution of the MCT by 28 days, with no recurrence in 93% of dogs at 84 days. Critical to TT's efficacy was the area of the wound (tissue deficit) after slough of the necrotic tumor relative to pretreatment tumor volume., Objectives: To analyze data collected during the previous study to (a) describe wounds after slough of treated MCTs and (b) identify determinants of wound area and speed of wound healing., Methods: Wound presence, condition, and area were determined from clinical records of 117 dogs over 84 days after a single intratumoral TT treatment., Results: Tumor slough occurred 3 to 14 days after treatment, exposing granulation tissue in the wound bed. Wound area after tumor slough in general was related to pretreatment tumor volume, with maximal recorded wound area fully evident in 89% of dogs by day 7. In dogs achieving complete tumor resolution, all wounds were left to heal by secondary intention. Bandaging and other wound management interventions only were required in 5 dogs. Time to healing (ie, full re-epithelialization of treatment site) depended on wound area and location on the body, with most wounds being fully healed between 28 and 42 days after treatment., Conclusions: Wound area and healing after slough of TT-treated tumors follow a consistent clinical pattern for most dogs., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.)

Background: Tigilanol tiglate (TT) is a novel small molecule approved by the European Medicines Agency for intratumoral treatment of mast cell tumors (MCTs) in dogs. In a randomized controlled clinical efficacy and safety study in the United States, 85 of 116 dogs that received a single TT injection achieved complete response (CR) of the treated MCT by day 28., Objective: To evaluate the durability of the TT treatment response achieved at day 28 in the U.S. study by assessing MCT recurrence at the treatment site 6 and 12 months after TT administration., Animals: Eighty-five dogs previously treated with TT., Methods: Dogs that achieved CR at day 28 were assessed retrospectively for the presence or absence of MCT at the treatment site using records from clinical visits and telephone interviews with owners. Dogs unavailable at an assessment time were considered lost-to-follow-up and data for their last assessment used in the final analysis., Results: By 12 months after TT treatment, 64 dogs remained evaluable, with 21 unavailable. Of evaluable patients, 57 (89%) remained tumor free at the treatment site and 7 (11%) had developed recurrence. All recurrences occurred within the first 6 months, predominantly (5/7, 71%) within the first 12 weeks., Conclusions and Clinical Importance: Tigilanol tiglate provided a durable long-term local response for the treatment of MCT in dogs., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.)

Objective: To evaluate the efficacy and safety of tigilanol tiglate (TT) for local intratumoral treatment of mast cell tumors (MCTs) in dogs., Methods: A randomized controlled clinical study in 2 phases involving 123 dogs with cytologically diagnosed MCT. Phase 1 compared 81 TT-treated dogs with 42 control dogs; phase 2 allowed TT treatment of control dogs and retreatment of dogs that failed to achieve tumor resolution after TT treatment in phase 1. Tigilanol tiglate (1 mg/mL) was injected intratumorally with dose based on tumor volume. Concomitant medications were used to minimize potential for MCT degranulation. Modified response evaluation criteria in solid tumors were used to evaluate treatment response at 28 and 84 days. Adverse events and quality of life were also assessed., Results: A single TT treatment resulted in 75% complete response (CR) (95% confidence interval [CI] = 61-86) by 28 days, with no recurrence in 93% (95% CI = 82-97) of dogs by 84 days. Eight TT-treated dogs that did not achieve CR in phase 1 achieved CR after retreatment, increasing the overall CR to 88% (95% CI = 77-93). Control dogs had 5% CR (95% CI = 1-17) at 28 days. Wound formation after tumor slough and wound size relative to tumor volume were strongly associated with efficacy. Adverse events typically were low grade, transient, and directly associated with TT's mode of action., Conclusions: Tigilanol tiglate is efficacious and well tolerated, providing a new option for the local treatment of MCTs in dogs., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Background: Epidemiologic studies suggest residential radon exposure might increase the risk of primary lung cancer in people, but these studies are limited by subject mobility. This limitation might be overcome by evaluating the association in pets., Hypothesis: Primary pulmonary neoplasia (PPN) rate is higher in dogs and cats residing in counties with a high radon exposure risk (Environmental Protection Agency [EPA] zone 1) compared to zones 2 (moderate radon exposure risk) and 3 (low radon exposure risk)., Animals: Six hundred ninety client-owned dogs and 205 client-owned cats with PPN., Methods: Retrospective review of medical records at 10 veterinary colleges identified dogs and cats diagnosed with PPN between 2010 and 2015. Each patient's radon exposure was determined by matching the patient's zip code with published county radon exposure risk. County level PPN rates were calculated using the average annual county cat and dog populations. The PPN counts per 100 000 dog/cat years at risk (PPN rates) were compared across radon zones for each species., Results: The PPN rate ratio in counties in high radon zone (1) was approximately 2-fold higher than in counties in lower radon zones for dogs (rate ratio zone 1 to 2, 2.49; 95% confidence interval [CI], 1.56-4.00; rate ratio zone 1 to 3, 2.29; 95% CI, 1.46-3.59) and cats (rate ratio zone 1 to 2, 2.13; 95% CI, 0.95-4.79; zone 1 to 3, 1.81; 95% CI, 0.9-3.61)., Conclusions and Clinical Importance: Exposure to household radon might play a role in development of PPN in dogs and cats., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Background: Chronic inflammation mediated by the cyclooxygenase enzymes, specifically their product prostaglandin E2 (PGE2), can result in the development of cancer. PGE2 promotes cell proliferation, apoptosis, and angiogenesis through interaction with its specific receptors (EP1 receptor - EP4 receptor [EP1R-EP4R]). In multiple human cancers, the expression of EP4R is associated with the development of malignancy and a poor prognosis. The expression of EP4R has not yet been evaluated in canine tumors. The aim of this study was to characterize the mRNA gene expression of EP4R (ptger4) in canine squamous cell carcinoma (SCC), apocrine gland anal sac adenocarcinoma (AGASACA), and transitional cell carcinoma (TCC). Archived tumor samples of canine cutaneous SCC (n = 9), AGASACA (n = 9), and TCC (n = 9), and matched archived normal tissue controls were evaluated for mRNA expression of canine EP4R using RNA in situ hybridization (RNAscope®). Quantification of RNAscope® signals in tissue sections was completed with an advanced digital pathology image analysis system (HALO). Data was expressed as copy number, H-index, and percent tumor cell expression of EP4R., Results: In all canine SCC, AGASACA, and TCC samples evaluated, strong universal positive expression of EP4R was identified. For SCC and AGASACA, mRNA EP4R expression was statistically higher than that of their respective normal tissues. The TCC tissues displayed significantly less mRNA EP4R expression when compared to normal bladder mucosa., Conclusions: These results confirm the mRNA expression of canine EP4R in all tumor types evaluated, with SCC and AGASACA displaying the highest expression, and TCC displaying the lowest expression. This study also represents the first reported veterinary evaluation of EP4R expression using the novel in situ hybridization technique, RNAscope®.

Background: Listeria monocytogenes is a promising therapeutic vaccine vector for cancer immunotherapy. Although highly attenuated, three cases of systemic listeriosis have been reported in people following treatment with Listeria-based therapeutic vaccines. This complication has thus far not been reported in canine patients., Case Presentation: A dog previously diagnosed with osteoblastic osteosarcoma was presented for care following administration of three doses of the Canine Osteosarcoma Vaccine-Live Listeria Vector. On routine staging chest radiographs, mild sternal lymphadenopathy and a right caudoventral thoracic mass effect were noted. Further evaluation of the mass effect with computed tomography and ultrasound revealed a cavitated mass associated with the 7th right rib. Aspirates of the mass cultured positive for Listeria monocytogenes. The mass and associated ribs were surgically removed. Histopathology was consistent with metastatic osteoblastic osteosarcoma. Treatment was continued with doxorubicin chemotherapy and at the time of publication, the dog was alive over 1 year following diagnosis with no evidence of further disease progression. Genotyping of the abscess-derived L. monocytogenes was consistent with the vaccine strain., Conclusions: This case represents the first veterinary case to describe development of a Listeria abscess following administration of a Listeria-based therapeutic vaccine.

Background: High-dose, pharmacological ascorbate (P-AscH - ) is preferentially cytotoxic to human cancer cells in vitro . Investigations on the efficacy of P-AscH - as an adjuvant treatment for multiple human cancers are on-going, but has yet to be formally investigated in dogs. The primary objectives of this study were to determine the pharmacokinetic (PK) profile of P-AscH - in healthy Beagle dogs and the effects of P-AscH - on canine osteosarcoma cells in vitro . Methods: Eight purpose-bred, healthy, spayed female Beagle dogs, between 20 and 21 months old, and 8-10 kg were administered two doses of P-AscH - (550 or 2,200 mg/kg) via intravenous infusion over 6 h, on separate days. Plasma ascorbate concentrations were measured at 12 time points during and after infusion for PK analysis using nonlinear mixed-effects (NLME) and non-compartmental analysis (NCA). Clonogenic assays were performed on 2 canine osteosarcoma cell lines (D-17 and OSCA-8) and canine primary dermal fibroblasts after exposure to high concentrations of ascorbate (75 pmoles/cell). Results: Plasma ascorbate levels in the dogs peaked at approximately 10 mM following 2,200 mg/kg and returned to baseline 6-8 h after dosing. Minor adverse effects were seen in two dogs. Ascorbate (75 pmoles/cell) significantly decreased survival in both the osteosarcoma cell lines (D-17 63% SD 0.010, P = 0.005; OSCA-8 50% SD 0.086, P = 0.026), compared to normal fibroblasts (27% SD 0.056). Conclusions: Pharmacological ascorbate is preferentially cytotoxic to canine-derived cancer cells. High levels of ascorbate can be safely administered to dogs. Further studies are needed to determine the effects of P-AscH - on canine patients., (Copyright © 2019 Musser, Mahaffey, Fath, Buettner, Wagner, Schneider, Seo, Mochel and Johannes.)

Appetite influences perceived quality of life for a dog or cat with cancer. Inappetence often is multifactorial, complicating treatment. Cancer-related anorexia/cachexia syndrome is a metabolic, paraneoplastic syndrome characterized by decreased food intake, involuntary weight loss, and loss of fat and muscle. If weight loss/cachexia has an impact on canine and feline cancer patients as in humans, management may improve survival times and quality of life. The challenge is having effective, proved therapies available for clinical use. Recent Food and Drug Administration approvals for appetite stimulation have renewed interest and discussion and has the potential to alter the course of case management., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The advent of the genome editing era brings forth the promise of adoptive cell transfer using engineered chimeric antigen receptor (CAR) T cells for targeted cancer therapy. CAR T cell immunotherapy is probably one of the most encouraging developments for the treatment of hematological malignancies. In 2017, two CAR T cell therapies were approved by the US Food and Drug Administration: one for the treatment of pediatric acute lymphoblastic leukemia (ALL) and the other for adult patients with advanced lymphomas. However, despite significant progress in the area, CAR T cell therapy is still in its early days and faces significant challenges, including the complexity and costs associated with the technology. B cell lymphoma is the most common hematopoietic cancer in dogs, with an incidence approaching 0.1% and a total of 20-100 cases per 100,000 individuals. It is a widely accepted naturally occurring model for human non-Hodgkin's lymphoma. Current treatment is with combination chemotherapy protocols, which prolong life for less than a year in canines and are associated with severe dose-limiting side effects, such as gastrointestinal and bone marrow toxicity. To date, one canine study generated CAR T cells by transfection of mRNA for CAR domain expression. While this was shown to provide a transient anti-tumor activity, results were modest, indicating that stable, genomic integration of CAR modules is required in order to achieve lasting therapeutic benefit. This commentary summarizes the current state of knowledge on CAR T cell immunotherapy in human medicine and its potential applications in animal health, while discussing the potential of the canine model as a translational system for immuno-oncology research.

Background: Gastrointestinal stromal tumors (GISTs) are uncommon intestinal neoplasms in the dog. Literature regarding adjunctive therapy for GISTs in dogs is sparse. High-risk GISTs in humans respond to tyrosine kinase inhibition in the adjuvant setting., Objectives: To review cases of toceranib phosphate use in dogs with GISTs and provide initial assessment of possible biological activity. A secondary aim was to evaluate patient and tumor characteristics for possible prognostic value., Animals: Twenty-seven dogs with confirmed GISTs based on histopathology and immunohistochemistry treated with toceranib., Methods: Retrospective study in which cases of toceranib use in dogs with GIST were solicited using the American College of Veterinary Internal Medicine Oncology and Small Animal Internal Medicine listservs., Results: Five of 7 dogs with gross disease experienced clinical benefit (71%; 3 complete responses, 1 partial response, 1 stable disease). These included 2 dogs with durable responses after toceranib discontinuation. Median progression-free interval (PFI) in dogs with gross disease was 110 weeks (range, 36-155 weeks). Median PFI in dogs with microscopic disease was 67 weeks (range, 9-257 weeks). Metastasis at diagnosis (P = 0.04) and high mitotic index (P < 0.001) were associated with shorter PFI in toceranib-treated dogs., Conclusions and Clinical Importance: Biological activity of toceranib is evident in dogs with gross disease. Metastasis of GIST at diagnosis, as well as high tumor mitotic index, was associated with shorter PFI in toceranib-treated dogs. Larger studies are needed to define postsurgical risk and refine the use of toceranib in dogs with gross and microscopic GIST., (© 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Background: Effective treatment options for inoperable, metastatic, or recurrent canine pheochromocytomas are lacking. In humans, specific germline mutations exist that drive the development of pheochromocytomas. Pharmaceutical blockade of these abnormalities with small molecule inhibitors are an effective treatment strategy. Similar mutations may exist in the dog, and thus, treatment with similar small molecule inhibitors may provide a survival advantage. The purpose of this study was to assess the role of toceranib phosphate in the treatment of inoperable, metastatic, or recurrent canine pheochromocytomas., Results: Retrospectively, medical records of dogs that had a diagnosis or suspect diagnosis of a pheochromocytoma were reviewed for information regarding response to toceranib phosphate and overall outcome. Five dogs were identified that fit the inclusion criteria. All five experienced clinical benefit (1 partial response, 4 stable disease). Progression-free interval (PFI) for the dog with the partial response was 61 weeks. PFI for the two dogs with stable measurable disease were 36 weeks and 28 weeks. PFI in the two dogs with stable metastatic disease were at least 11 weeks and 18 weeks., Conclusions: Based on this limited series of dogs, the results suggest that toceranib may have biological activity in dogs with primary and metastatic pheochromocytomas. Larger studies are needed to define the use and response to toceranib in dogs with gross, microscopic, and metastatic pheochromocytoma.

Background: The gastrointestinal (GI) microbiota in healthy cats is altered in IBD. Little research has been performed to identify whether specific bacterial groups are associated with small cell GI lymphoma (LSA)., Hypothesis: Mucosal bacteria, including Enterobacteriaceae and Fusobacterium spp., are abundant in intestinal biopsies of cats with small cell GI LSA compared to cats with IBD., Animals: Fourteen cats with IBD and 14 cats with small cell GI LSA., Methods: Retrospective case control study. A search of the medical records was performed to identify cats diagnosed with IBD and with GI LSA. Bacterial groups identified by FISH in GI biopsies were compared between cohorts and correlated to CD11b + and NF-κB expression., Results: Fusobacterium spp. (median; IQR bacteria/region) were higher in cats with small cell GI LSA in ileal (527; 455.5 - 661.5; P = .046) and colonic (404.5; 328.8 - 455.5; P = .016) adherent mucus, and combined colonic compartments (free mucus, adherent mucus, attaching to epithelium) (8; 0 - 336; P = .017) compared to cats with IBD (ileum: 67; 31.5 - 259; colon: 142.5; 82.3 - 434.5; combined: 3; 0 - 34). Bacteroides spp. were higher in ileal adherent mucus (P = .036) and 3 combined ileal compartments (P = .034) of cats with small cell GI LSA. There were significant correlations between Fusobacterium spp. totals and CD11b + cell (P = .009; rs .476) and NF-κB expression (P = .004; rs .523)., Conclusions: The bacterial alterations appreciated might be influential in development of small cell GI LSA, and should drive further studies to elucidate the effects of microbial-mediated inflammation on GI cancer progression., (© 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Objectives The purpose of this study was to solicit and compile data from practicing veterinary specialists regarding their use of toceranib in cats with mast cell neoplasia and to provide initial assessment of possible clinical benefit and adverse events. Methods The American College of Veterinary Internal Medicine and Oncology listservs were used to solicit data pertaining to cases in which toceranib was used in the treatment of feline mast cell neoplasia. Cases were included if the following data were received: signalment (age, sex, breed), diagnosis of mast cell neoplasia by either cytology or histopathology, anatomic classification of disease (cutaneous, splenic/hepatic, gastrointestinal, other), previous and concurrent treatment, toceranib dose (mg/kg) and schedule, duration of therapy, best response and documentation of adverse events. Results Case data from 50 cats with cutaneous (n = 22), splenic/hepatic (visceral) (n = 10), gastrointestinal (n = 17) or other (n = 1) mast cell neoplasia were received. Clinical benefit was seen in 80% (40/50), including 86% (19/22) with cutaneous, 80% (8/10) with visceral and 76% (13/17) with gastrointestinal involvement. A majority of cats (n = 35) received glucocorticoids during toceranib treatment. Median duration of treatment in cats experiencing clinical benefit was 36 weeks (range 4-106 weeks), 48 weeks (range 12-199 weeks) and 23 weeks (range 13-81 weeks) for cutaneous, visceral and gastrointestinal cases, respectively. Toceranib was administered at a median dose of 2.5 mg/kg (range 1.6-3.5 mg/kg); in 90% (45/50) the drug was given three times per week. Treatment was generally well tolerated with 60% (30/50) of cats experiencing adverse events. The majority of these events were low-grade (grade 1 or 2) gastrointestinal or hematologic events that resolved with treatment break and/or dose adjustment. Conclusions and relevance Toceranib appears to be well tolerated in feline patients with mast cell neoplasia. Biologic activity of this drug is evident in the studied cats; however, further prospective studies are needed to elucidate fully its role in treatment of this disease.

Baculoviruses are commonly used for recombinant protein and vaccine production. Baculoviruses are nonpathogenic to vertebrates, have a large packaging capacity, display broad host and cell type tropism, infect both dividing and nondividing cells, and do not elicit strong immune or allergic responses in vivo . Hence, their use as gene delivery vehicles has become increasingly popular in recent years. Moreover, baculovirus vectors carrying mammalian regulatory elements can efficiently transduce and express transgenes in mammalian cells. Based on the finding that heparan sulfate, which is structurally similar to heparin, is an attachment receptor for baculovirus, we developed a novel scalable baculovirus purification method using heparin-affinity chromatography. Baculovirus supernatants were loaded onto a POROS heparin column, washed to remove unbound materials, and eluted with 1.5 mol/l NaCl, which yielded a recovery of purified baculovirus of 85%. After ultracentrifugation, baculovirus titers increased from 200- to 700-fold with overall yields of 26-29%. We further show that baculovirus particles were infectious, normal in morphology and size, despite high-salt elution and shear forces used during purification and concentration. Our chromatography-based purification method is scalable and, together with ultracentrifugation and/or tangential flow filtration, will be suitable for large-scale manufacturing of baculovirus stocks for protein and vaccine production and in gene therapy applications.

Background: Aggregation and aggregation-mediated formation of toxic alpha synuclein (aSyn) species have been linked to the pathogenesis of sporadic and monogenic Parkinson's disease (PD). A novel H50Q mutation of aSyn, resulting in the substitution of histidine by glutamine, has recently been identified in PD patients. We have previously shown that the lipid peroxidation product 4-hydroxy-2-nonenal (HNE) induces the formation of HNE-aSyn adducts, thereby promoting aSyn oligomerization and increasing its extracellular toxicity to human dopaminergic neurons. Intriguingly, we identified histidine 50 (H50) of aSyn as one of the HNE modification target residues. These converging lines of evidence support the hypothesis that changes in H50 via posttranslational modification (PTM) and mutation trigger the formation of aggregated, toxic aSyn species, which interfere with cellular homeostasis. In the present study, we aim to elucidate 1) the role of H50 in HNE-mediated aSyn aggregation and toxicity, and 2) the impact of H50 mutation on aSyn pathology. Besides the PD-related H50Q, we analyze a PD-unrelated control mutation, in which H50 is replaced by an arginine residue (H50R)., Results: Analysis of HNE-treated aSyn revealed that H50 is the most susceptible residue of aSyn to HNE modification and is crucial for HNE-mediated aSyn oligomerization. Overexpression of aSyn with substituted H50 in H4 neuroglioma cells reduced HNE-induced cell damage, indicating a pivotal role of H50 in HNE modification-induced aSyn toxicity. Furthermore, we showed in vitro that H50Q/R mutations substantially increase the formation of high density and fibrillar aSyn species, and potentiate the oligomerization propensity of aSyn in the presence of a nitrating agent. Cell-based experiments also revealed that overexpression of H50Q aSyn in H4 cells promotes aSyn oligomerization. Importantly, overexpression of both H50Q/R aSyn mutants in H4 cells significantly increased cell death when compared to wild type aSyn. This increase in cell death was further exacerbated by the application of H2O2., Conclusion: A dual approach addressing alterations of H50 showed that either H50 PTM or mutation trigger aSyn aggregation and toxicity, suggesting an important role of aSyn H50 in the pathogenesis of both sporadic and monogenic PD.

Objective: To characterize the biological behavior and prognostic factors associated with hemangiosarcoma in cats., Design: Retrospective case series., Animals: 53 cats with hemangiosarcoma., Procedures: Data were retrieved from a state veterinary diagnostic laboratory, 3 veterinary colleges, and a private practice., Results: Cutaneous and subcutaneous tumor locations were more common than visceral (abdominal and thoracic) and oral locations. Surgical excision was the primary treatment in 47 cats. Tumor-free surgical margins were more likely in cutaneous than subcutaneous lesions and were associated with longer survival times. Local recurrence was observed in 6 of 12 cats with subcutaneous lesions for which follow-up was available. Metastatic disease was detected in 5 of 13 cats with adequate staging at initial diagnosis. A sixth cat had pulmonary metastases at the time of euthanasia. In 4 of 10 cats with visceral hemangiosarcoma, the diagnosis was made at necropsy or they were euthanized at the time of diagnosis. Adjuvant therapy was uncommonly used. Eighteen of the 21 known deaths or euthanasias were tumor-related. Higher mitotic counts (> 3 in 10 hpfs) were associated with shorter survival times., Conclusions and Clinical Relevance: Subcutaneous hemangiosarcoma was more biologically aggressive than the cutaneous form and was more likely to recur locally and result in euthanasia or death of the cat. Metastatic potential of the cutaneous and subcutaneous forms may be greater than previously reported. Visceral hemangiosarcoma is associated with a grave prognosis.