Definitive-intent uniform megavoltage fractioned radiotherapy protocol for presumed canine intracranial gliomas: retrospective analysis of survival and prognostic factors in 38 cases (2013-2019).

BACKGROUND: Radiotherapy (RT) is currently considered the treatment of choice for presumed canine intracranial gliomas. However, variable therapeutic responses are described, due to heterogeneous populations and different radiation methods or protocols. Only one study dedicated to intracranial suspected glioma highlighted prognostic criteria. Determination or confirmation of specific clinical and imaging prognostic factors may guide the therapeutic management of these tumours. The objectives were to provide data on long-term clinical outcome (including quality of life, QoL) and to determine specific prognostic factors associated with survival time. We report a single-institution retrospective study, including all dogs with suspected symptomatic primary solitary intracranial glioma, treated with a complete uniform fractionated megavoltage radiation protocol of 15x3Gy over 5 weeks, between January 2013 and February 2019. Thirty-eight client-owned dogs were included. Medical records were retrospectively evaluated for median overall survival time (MST), clinical and imaging responses. Prognostic factors on survival were researched in terms of signalment, clinical presentation, tumour imaging characteristics and response following RT. Finally, the RT's impact on the dogs' clinical signs and Qol were evaluated by the owners. RESULTS: The disease-specific MST was 698 days (95% CI: 598-1135). Survival at 1 and 2 years were respectively 74.2 ± 7.4% and 49.0 ± 9.8%. Initial clinical signs were related to survival, as well as tumour characteristics such as cystic-pattern, mass effect and Tumour/Brain volume ratio. No significant adverse effect or radiotoxicity was observed. CONCLUSIONS: RT appears as a safe and effective treatment for canine intracranial gliomas, allowing long-term tumour control, improvement of life's quality and management of associated clinical signs. The initial clinical signs and MRI characteristics (Tumour/Brain volume ratio, cyst-like lesion and mass effect) may help predict the prognosis.

[Continuous haemodialysis with citrate anticoagulation in patients with liver failure: three cases]. / Hémodialyse continue avec anticoagulation au citrate chez l'insuffisant hépatique : à propos de trois cas.

Regional citrate anticoagulation for continuous renal replacement therapy provides an efficient alternative to heparin as it reduces the likelihood of haemorrhage in critically ill patients with bleeding risk or coagulopathy and increases the haemofilter survival time. Liver failure is a classic contraindication of regional citrate anticoagulation since it carries the risk of citrate accumulation and its metabolic complications, although it could be attractive for this population of patients with high bleeding risk. We report three cases of continuous haemodialysis with regional citrate anticoagulation performed in patients with severe acute liver failure, without accumulation in two cases and with a suspected beginning of accumulation in the third case. For these patients, close monitoring of the total-to-ionized calcium ratio, pH and anion gap is particularly essential to control the safety of citrate infusion. Increasing effluent flow rate eliminates more calcium-bound citrate and therefore limits citrate accumulation and its consequences.

Emesis in dogs: a review.

Emesis is a common presenting sign in small animal practice. It requires a rational approach to management that is based upon a sound understanding of pathophysiology combined with logical decision making. This review, which assesses the weight of available evidence, outlines the physiology of the vomiting reflex, causes of emesis, the consequences of emesis and the approach to clinical management of the vomiting dog. The applicability of diagnostic testing modalities and the merit of traditional approaches to management, such as dietary changes, are discussed. The role and usefulness of both traditional and novel anti-emetic drugs is examined, including in specific circumstances such as following cytotoxic drug treatment. The review also examines areas in which common clinical practice is not necessarily supported by objective evidence and, as such, highlights questions worthy of further clinical research.

Masitinib is safe and effective for the treatment of canine mast cell tumors.

BACKGROUND: Activation of the KIT receptor tyrosine kinase is associated with the development of canine mast cell tumors (MCT). HYPOTHESIS/OBJECTIVE: To evaluate the efficacy of masitinib, a potent and selective inhibitor of KIT, in the treatment of canine MCT. ANIMALS: Two hundred and two client-owned dogs with nonmetastatic recurrent or nonresectable grade II or III MCT. METHODS: Double-blind, randomized, placebo-controlled phase III clinical trial. Dogs were administered masitinib (12.5 mg/kg/d PO) or a placebo. Time-to-tumor progression (TTP), overall survival, objective response at 6 months, and toxicity were assessed. RESULTS: Masitinib increased overall TTP compared with placebo from 75 to 118 days (P = .038). This effect was more pronounced when masitinib was used as first-line therapy, with an increase in the median TTP from 75 to 253 days (P = .001) and regardless of whether the tumors expressed mutant (83 versus not reached [P = .009]) or wild-type KIT (66 versus 253 [P = .008]). Masitinib was generally well tolerated, with mild (grade I) or moderate (grade II) diarrhea or vomiting as the most common adverse events. CONCLUSIONS AND CLINICAL IMPORTANCE: Masitinib is safe and effective at delaying tumor progression in dogs presenting with recurrent or nonresectable grade II or III nonmetastatic MCT.

A kinetic study of histopathological changes in the subcutis of cats injected with non-adjuvanted and adjuvanted multi-component vaccines.

The aim of this study was to investigate the subcutaneous tissue response to administration of a single dose of multi-component vaccine in the cat. Three groups of 15 cats were injected with one of three vaccine products with saline as a negative control. Cats in group A received non-adjuvanted vaccine; cats in group B received vaccine with a lipid-based adjuvant; whilst those in group C were vaccinated with a product adjuvanted with an alum-Quil A mixture. The vaccine and saline injection sites were sampled on days 7, 21 and 62 post-vaccination. Biopsies of these vaccine sites were examined qualitatively and scored semi-quantitatively for a series of parameters related to aspects of the inflammatory and tissue repair responses. These data were analysed statistically, including by principal component analysis. At all three time points of the experiment, there was significantly less inflammation associated with administration of non-adjuvanted vaccine (p=0.000). Although there was evidence of tissue repair by day 62 in all groups, those cats receiving adjuvanted vaccines had evidence of residual adjuvant material accumulated within macrophages at this late time point. The severity of tissue reactions may vary significantly in response to vaccines which include adjuvants or are non-adjuvanted.

In vivo retroviral mediated gene transfer into bladder urothelium results in preferential transduction of tumoral cells.

OBJECTIVES: Superficial bladder tumours are at high risk for recurrence, relapse after resection, escape to intravesical immunotherapy and they may become invasive. New therapeutics are therefore needed to achieve cure. Thus, gene therapy is an attractive new treatment modality for malignant bladder tumours. The purpose of this study was to evaluate the feasibility and the efficiency of retroviral mediated reporter gene transfer into malignant urothelial cells both in vitro and in vivo. METHODS: We evaluated the feasibility of the transfection of bladder tumour with direct intravesical instillation of a defective retrovirus. The vector was derived from LXSN. The efficiency of transduction with the Moloney Leukaemia Murine virus-based vector, amphotrophic retroviral vector, was monitored through the expression of two marker genes (nls-LacZ and NeoR). The canine animal was chosen since it can present with spontaneous bladder carcinomas mimicking human pathology. Primary cultures of two normal canine bladder urothelium and two canine primary bladder tumours were first studied. We then investigated in vivo, in two normal and two spontaneous tumour bearing dogs, the transduction of urothelial cells following direct intravesical instillation of 2.10(4) to 3.10(6) of the retroviral vector. RESULTS: Transduced cells were evidenced in all primary cultures of canine normal urothelium and transitional cell carcinoma. Bladder biopsies from sound dogs instilled with the viral solution showed long lasting transduction up to 60 days long. Bladder cryosections from tumour-bearing dogs displayed transduction of superficial layers of urothelial cancer cells without passing through lamina propria. In vivo transduction was evidenced in 1 to 15% (mean 5%) of the cells in the tumours and preferentially addressed malignant cells. Normal epithelium either originating from sound or tumour-bearing animals was not transduced. CONCLUSION: These results demonstrate for the first time the feasibility of in vivo retroviral transduction of bladder cancer using a clinically relevant procedure.

Local immunotherapy of spontaneous feline fibrosarcomas using recombinant poxviruses expressing interleukin 2 (IL2).

We tested the canarypox virus vector ALVAC and the genetically attenuated vaccinia virus vector NYVAC as vehicles for achieving local immunomodulation in domestic animals bearing spontaneous tumours. Following intratumoral administration of ALVAC-, or NYVAC-luciferase in dogs with melanoma, it was demonstrated that viral recombinants remained localized along the needle track, with no virus detectable in the periphery of the tumour. Given these distribution characteristics and their well-documented safety profile, ALVAC- or NYVAC-based recombinants expressing feline or human IL2, respectively, were administered to domestic cats, in order to prevent the recurrence of spontaneous fibrosarcomas. In the absence of immunotherapy, tumour recurrence was observed in 61% of animals within a 12-month follow-up period after treatment with surgery and iridium-based radiotherapy. In contrast, only 39 and 28% of cats receiving either NYVAC-human IL2 or ALVAC-feline IL2, respectively, exhibited tumour recurrences. Based on such results, and in the context of ongoing clinical studies conducted in humans, we discuss the utilization of ALVAC- or NYVAC-based recombinants as viable therapeutic modalities for local immunotherapy or therapeutic vaccination against cancer, both in humans and companion animals.

Stereotactic CT-guided brain biopsy in the dog.

This study evaluated the accuracy of a new stereotactic CT-guided brain biopsy (SCTGBB) device on 23 client-owned dogs which presented with a brain lesion. Biopsy of the lesion was achieved in 95 per cent of cases. The target tissue was not sampled in one dog. Complications were observed in six dogs. Two dogs with highly vascularised brainstem tumours died after SCTGBB. Minor complications (slight variation in the neurological status) were observed in a further four cases. A diagnosis was reached in 16 dogs after cytological examination and in 21 dogs after histological evaluation. SCTGBB is an accurate diagnostic method for the diagnosis of brain lesions.

Adenovirus-mediated gene transfer in canine eyes: a preclinical study for gene therapy of human uveal melanoma.

BACKGROUND: Melanomas of the uveal tract are the most common intraocular malignancies in adults, with an incidence of six cases per million adults per year. Enucleation, which may enhance the dissemination of tumour cells into the systemic circulation, is still required for eyes with large tumours. Gene therapy is proposed as a new therapeutic approach for uveal melanoma management. METHODS: The potential of adenovirus-mediated gene transfer to normal eyes of two laboratory Beagles and in an iris tumour of a Great Dane were evaluated. Replication-defective adenoviral vectors (Adbetagal) were used to assess the feasibility, efficiency and safety of direct adenoviral delivery to the anterior chamber of normal eyes and to an iris tumour. The expression of angiostatin into the aqueous humour following an adenoviral-mediated delivery of human angiostatin (AdK3) was also investigated. RESULTS: The ciliary body was the area preferentially transduced after adenoviral injection into the anterior chamber. It was also demonstrated that a direct intratumoral injection of a recombinant adenovirus efficiently transduces a canine uveal melanoma. Western blot analysis performed on the aqueous humour revealed that the expression of the angiostatin recombinant protein in the aqueous humour correlated with the dose of AdK3 administered. Lymphocyte infiltrates at the site of AdK3 injection indicated induction of a strong cellular immune response, and humoral immune responses developed in all three dogs. CONCLUSIONS: The present study involving adenovirus-mediated gene transfer to dog eyes provides an essential basis for gene therapy treatment of uveal melanoma-bearing patients.

In vivo model mimicking natural history of dog prostate cancer using DPC-1, a new canine prostate carcinoma cell line.

BACKGROUND: Dog prostate cancer is usually considered to be highly relevant to human prostate cancer. We report the isolation of a new canine prostate cancer epithelial cell line designated DPC-1. METHODS: Primary cultures were established from a canine poorly differentiated prostatic adenocarcinoma. Population doubling time was determined by counting nuclei after cell lysis. Tumorigenicity was assessed in nude mice and in one adult immunodeficient dog. Immunoscintigraphy was performed in both models using a monoclonal antibody (mAb) raised against the [44-62] sequence of human PSMA. RESULTS: DPC-1 cells have a rapid growth in vitro (doubling time, 27 hr) which is not stimulated by androgens. In addition, DPC-1 displays immunoreactivity to human PSA and PSMA. DPC-1 was found to be highly tumorigenic not only in nude mice but also for the first time after orthotopic seeding in an immunodeficient dog. This allograft mimicked, in a compressed form, the aggressive biological behavior of spontaneous dog prostate adenocarcinoma. Immunoscintigraphy using a (131)Iodine-labeled PSMA mAb clearly visualized induced tumors in nude mice and in the dog allograft. CONCLUSIONS: This study suggests that DPC-1 may constitute a powerful model for assessing new diagnostic and/or therapeutic tools in the management of prostate cancer.

Accuracy testing of a new stereotactic CT -guided brain biopsy device in the dog.

The accuracy testing of a new CT -guided stereotactic device was undertaken via an experimental study. Ten dog cadaver heads were submitted to a CT examination and a brain target was determined (coordinates: x1, y1, z1). 0.3 ml of a radiopaque paste was injected in this chosen point. The head was analysed twice by CT and the centre of the injection (x2, y2, z2) was measured on slices. Tridimensional statistical analysis of the variance of the two points was carried out. The procedure always led to the injection of the radiopaque paste and created an intracerebral mass which gave a measurable image on CT examination. The distance between the original target and the centre of the injection was 2.9 +/- 1.08 mm. It is concluded that this new device allows the opportunity to perform stereotactic CT -guided brain biopsy for all unknown brain lesions exceeding 6 mm in diameter in the dog.

Pleuro-pulmonary tumours detected by clinical and chest X-ray analyses in rats transplanted with mesothelioma cells.

New strategies for cancer therapy must be developed, especially in severe neoplasms such as malignant pleural mesothelioma. Animal models of cancer, as close as possible to the human situation, are needed to investigate novel therapeutical approaches. Orthotopic transplantation of cancer cells is then relevant and efforts should be made to follow up tumour evolution in animals. In the present study, we developed a method for the orthotopic growth of mesothelioma cells in the pleural cavity of Fischer 344 and nude rats, along with a procedure for clinical survey. Two mesothelioma cell lines, of rat and human origin, were inoculated by transthoracic puncture. Body weight determination and chest X-ray analyses permitted the follow-up of tumour evolution by identifying different stages. Autopsies showed that tumours localized on the whole pleural cavity (diaphragm, parietal pleura), mediastinum and pericardium. Tumour morphology and antigenic characteristics were consistent with those of the inoculated cells and were similar in both types of rats inoculated with the same cell type. These results demonstrate that mesothelioma formation in rats can be followed up by clinical and radiographic survey after gentle intrathoracic inoculation of mesothelioma cells, thus allowing the definition of stages of interest for further experimental trials.

Modulated release of IdUrd from poly (D,L-lactide-co-glycolide) microspheres by addition of poly (D,L-lactide) oligomers.

This paper reports the release characteristics of a radiosensitizer, 5-iodo-2'-deoxyuridine (IdUrd), from poly (D,L-lactide-co-glycolide) 50: 50 (PLGA) microparticles obtained by a phase separation technique. Poly (D,L-lactide) oligomers (D,L-PLA) were incorporated into the PLGA matrix in order to accelerate the overall drug release rate and regulate the triphasic release profile exhibited by the standard PLGA microparticles. For D,L-PLA (800), the burst effect was large and the IdUrd release was complete between 28 and 35 days. These results were attributed to rapid pore formation on the periphery of the microsphere in the early stages of incubation, due to hydrosolubility of the smallest oligomers (D,L-PLA (800)). In the case of D,L-PLA (1,100), drug release occurred over a six week period, the standard time course of conventional radiation therapy. The period during which the radiosensitizer was incorporated in human brain tumor cell nuclei after its entrapment in biodegradable microspheres was determined by using an organotypical tissue culture. The presence of radiosensitizer in the DNA of tumor cell nuclei was detected by immunohistochemical labelling of tumor fragments. IdUrd release from standard microspheres (7+/-0.5 weeks) was longer than from oligomer-containing batches. For D,L-PLA (800)-containing microspheres, the radiosensitizer was entirely released within 4. 5+/-0.5 weeks. The microspheres containing D,L-PLA (1,100) allowed an IdUrd release over a 5 to 6 week period. The ex vivo data were consistent with the in vitro findings in terms of release duration.

Adenovirus-mediated gene transfer in dog prostate: a preclinical study of a relevant model system for gene therapy of human prostatic cancer.

This present study evaluates the potential of adenovirus-mediated gene transfer (AMGT) to the prostate of normal laboratory beagles. Many morphological and histological similarities can be noted between dog and human prostate. Moreover, dogs can spontaneously develop prostate cancer with a clinical and biological outcome identical to that in man. Firstly we showed the capacity of human adenovirus to infect canine prostatic cells in vitro. Secondly, we injected transrectally in the dogs' prostates 2x10(9) plaque forming units of a first generation recombinant adenovirus vector harboring the reporter gene beta-galactosidase (AdRSVbetagal). Seven days after the adenoviral delivery, we observed expression of the transgene in both prostates, and exclusively in epithelial cells. Despite a cellular and a humoral immune response, the infusion appeared safe, since the dogs had no fever and presented no urinary symptoms. This study constitutes the first evaluation of AMGT in dog prostate and provides a basis for gene therapy treatment of prostate carcinoma-bearing patients.

Cranioplasty after en bloc resection of calvarial chondroma rodens in two dogs.

The clinical features of chondroma rodens in two dogs and the treatment using radiation therapy, en bloc resection of the tumours and cranioplasties with a bone allograft (case 1) and a polymethylmethacrylate implant (case 2) are described. The dogs were still alive with no local recurrence of the tumours 30 and 18 months, respectively, after surgery. En bloc resection and calvarial reconstruction in the treatment of chondroma rodens are discussed.

Diagnosis of pulmonary thromboembolism in a cat using echocardiography and pulmonary scintigraphy.

A 10-year-old male cat was presented with sudden onset of respiratory difficulties. Clinical examination revealed an acute dyspnoea with cyanosis associated with a left systolic heart murmur. Standard thoracic radiographs excluded pulmonary oedema and showed very few pulmonary changes given the intensity of the respiratory compromise. Echocardiographic examination revealed hypertrophic cardiomyopathy and a thrombus in the right pulmonary artery. Pulmonary scintigraphy confirmed a pulmonary thromboembolism with hypovascularisation of the left cranial lobe and of the ventral segment of the right lobe. Conservative treatment was instituted using an antibiotic (doxycycline), anticoagulants (heparin, coumadine) and a calcium inhibitor (diltiazem). The cat was given absolute rest. The general condition of the animal improved.

First clinical trial of cat soft-tissue sarcomas treatment by electrochemotherapy.

Electrochemotherapy combines bleomycin and local electric pulses that allow cell permeabilization and free access of bleomycin to its intracellular target. We report the first veterinarian clinical trial of electrochemotherapy in 12 cats with spontaneous large soft-tissue sarcomas that suffered relapse after treatment with conventional therapies. Permeabilizing electric pulses were delivered using external surface electrodes, as well as new needle-shaped electrodes that were designed to be inserted in tumours for more effective treatment of several-centimetre-thick tumour nodules. The electric pulses were applied to the tumours several times from 4 to 15-30 min after a bolus intravenous injection of 0.5 mg kg(-1) bleomycin. Tolerance to treatment was excellent without general side-effects. The cats showed local inflammatory reactions for a few days and disease stabilization lasted from 2 weeks to 7 months. One partial regression was observed, and the general absence of nodule volume decrease can be explained by local fibrotic reactions. Histological analysis of biopsies also revealed massive tumour cell death. The cats' lifespan increased (P<<0.001), with a mean survival time of 6.1 months (maximum 18 months) compared with 0.8 months (maximum 1.5 months) for a group of 11 untreated control cats displaying similar carcinological features. Electrochemotherapy is clearly effective as a salvage treatment for large spontaneous solid tumours in adverse clinical situations and this is promising for future applications.

Gene therapy of spontaneous canine melanoma and feline fibrosarcoma by intratumoral administration of histoincompatible cells expressing human interleukin-2.

The production of human interleukin-2 (hIL-2) local to the tumor site by engineered histoincompatible cells has been shown in various murine models to promote a strong immune response leading to tumor growth inhibition or rejection. To assess whether this strategy would be similarly applicable for treatment of primary neoplastic cells, two naturally occurring tumors were used as preclinical models; the highly metastatic melanoma of the dog and the low metastatic fibrosarcoma of the cat. We demonstrate that both cats and dogs when treated by tumor surgery, radiotherapy and repeated local injections of xenogeneic Vero cells secreting high levels of hIL-2 relapse less frequently and survive longer than control animals treated by surgery and radiotherapy alone. Local secretion of hIL-2 by the xenogeneic cells is shown to be necessary for the induction of an optimal antitumor effect. Moreover, the safety of the procedure was demonstrated in both animal models and through extensive toxicological analysis performed in rats. These results confirm for the first time to our knowledge the safety and therapeutic potential of a gene transfer strategy in animals with spontaneous metastatic and nonmetastatic tumors.

Effects of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) on haematopoietic regeneration and resistance to infection of sublethally irradiated mice.

The influence of polar glycopeptidolipids of Mycobacterium chelonae (pGPL-Mc) treatment on the reversal of irradiation-induced leukopenia (granulocytopenia, monocytopenia) and thrombocytopenia and its ability to protect mice against lethal infections were investigated in this study. The administration of pGPL-Mc to irradiated mice significantly accelerated the recovery of leukocyte and thrombocyte numbers in the peripheral blood. Granulocytes and monocytes were the principal cells of the leukocyte population that responded to the potent stimulus of this product. The reversal of granulocytopenia and monocytopenia in treated mice was achieved on day 14 and reached a peak value on day 20. Responses in mice receiving 100 mg/kg of pGPL-Mc was about 40-fold compared to controls and about 4-fold compared to the rhG-CSF-treated group. Normal levels of thrombocytes were reached by day 17 in mice treated with 100 mg/kg and by day 20 in those receiving 25 mg/kg of pGPL-Mc. The administration of pGPL-Mc to mice with irradiation-induced granulocytopenia was characterized by highly significant protection of these animals against lethal Klebsiella pneumoniae or Escherichia coli infections. Therefore, pGPL-Mc appears to possess a considerable potential for improvement of the outcome of radiotherapy and may contribute to the successful avoidance of irradiation-induced toxicities.