Hyperglycaemia but not hyperlipidaemia causes beta cell dysfunction and beta cell loss in the domestic cat

Aims/hypothesis: In vitro studies point to a toxic effect of high glucose and non-esterified fatty acids on beta cells. Whether elevated levels of glucose and lipids induce beta cell loss in vivo is less clear. The domestic cat has recently been proposed as a valuable animal model for human type 2 diabetes because feline diabetes shows several similarities with diabetes in humans, including obesity-induced insulin resistance, impaired beta cell function, decreased number of beta cells and pancreatic amyloid deposition. Methods: We infused healthy cats with glucose or lipids for 10days to clamp their blood concentrations at the approximate level found in untreated feline diabetes (glucose: 25-30mmol/l; triacylglycerols: 3-7mmol/l). Results: Glucose and lipid levels were adequately targeted. Plasma non-esterified fatty acids were increased by lipid infusion 1.7-fold. A dramatic and progressive decline of plasma insulin levels was observed in glucose-infused cats beginning after 2days of hyperglycaemic clamp. In contrast, plasma insulin concentration and glucose tolerance test were not affected by hyperlipidaemia. Compared with controls, glucose-infused cats had a 50% decrease in beta cells per pancreatic area. Apoptotic islet cells and cleaved caspase-3-positive beta cells were observed in glucose-infused cats only. Conclusions/interpretation: Sustained hyperglycaemia but not hyperlipidaemia induces early and severe beta cell dysfunction in cats, and excess glucose causes beta cell loss via apoptosis in vivo. Hyperglycaemic clamps in cats may provide a good model to study the pathogenesis of glucose toxicity in beta cell

Clinical, laboratory and pathological findings in cats experimentally infected with Aelurostrongylus abstrusus

Aelurostrongylus abstrusus parasitizes the respiratory tract and can heavily affect the breathing and general condition of cats. Experimental infections of six cats were initiated by intragastric administration with 100 or 800 third-stage larvae (L3) obtained from the terrestrial snail Helix aspersa. First-stage larvae were isolated from faecal samples after 35-41days post infection (dpi) in five animals and until end of study (84dpi) in two cats. Cough and respiratory sounds were observed starting from 28 to 41dpi and dyspnoea and panting starting from 52dpi. All cats had enlarged lymph nodes and, starting from 56dpi, reduced body weight, and four cats showed intermittent reduced general condition with apathia and anorexia. Eosinophilia and leucocytosis partially with massive lymphocytosis, and occasional basophilia and monocytosis were observed. Mild anaemia was present in five cats, while alterations in coagulation parameters suggested stimulation of the coagulation cascade with increased consumption of coagulation factors (delayed PT, hypofibrinogenemia). Adult A. abstrusus specimens were isolated from the five patent cats at necropsy and all six cats showed pathological changes in the lungs, including disseminated inflammatory cell infiltrates, often associated with incorporated larvae and eggs. There was some degree of overlap between the severity and the inoculation doses. Infections starting from 100 L3 of A. abstrusus had an impact on the lung tissues and on the health of the cats, despite the presence of only mild haematological abnormalities. Due to the worldwide occurrence of feline lung worms, parasitic infections should be considered in the differential diagnosis of lung diseases regardless of the presence of clinical signs and larval excretion

First meeting of the European canine lymphoma group: Workshop: State of the art and comparative aspects in canine lymphoma: CH-Lugano, 22 June 2013

This satellite meeting to the 12th International Conference on Malignant Lymphoma was conceived to bring together European researchers focused on canine lymphoma to explore several facets of this promising model of human disease. A series of invited lectures showed striking similarities between the two diseases namely in topics related to pathogenesis, diagnosis and classification and therapy. In particular, the potential value of the model was shown at the level of the NF-kappa B/p65 pathway, the Bcl-2 family of proteins, Ki67 and the S-phase fraction, as well as the MMPs, VEGF and PDGF. The utility of the growing body of well-characterized canine cell lines was stressed. The value of cytology and flow cytometry as tools for diagnosis, disease progression monitoring and prognosis were emphasized, whereas the failure so far of the standard immunohistochemical panel to differentiate between germinal centre and non-germinal centre diffuse large B-cell lymphomas subtypes in dogs was discussed. Further contributions included the report of encouraging results from a chemo-immunotherapy trial administered to dogs with diffuse large B-cell lymphoma, an overview on the use of radiation therapy for canine lymphoma and the role of surgery in splenic lymphoma. Altogether, the success of this meeting, attended by more than 160 participants, documents the rising interest for the spontaneous canine lymphoma model. Copyright (C) 2013 John Wiley & Sons, Ltd

A review of canine B cell clonality assays and primer set optimization using large-scale repertoire data

Several molecular clonality assays have been developed to assess canine B cell proliferations. These assays were based on different sequence data, utilized different assay designs and employed different testing strategies. This has resulted in a complex body of literature and complicates evidence-based selection of primer sets. In addition, further refinement of primer sets is difficult because it is unknown how well current primer sets cover the expressed sequence repertoire. The objectives of this study were 1) to provide an overview of published IGH clonality assays that highlights key differences in assay design and testing strategy and 2) to propose a novel method for optimizing primer sets that leverages large-scale sequencing data. A review of previously published assays highlighted confounding factors that hamper a direct comparison of performance metrics between studies. These findings illustrate the need for a multi-institutional effort to harmonize veterinary clonality testing. A novel in silico analysis of primer sequences using a large dataset of expressed sequences identified shortfalls of existing primer sets and was used to guide primer optimization. Three optimized primer sets were tested and yielded qualitative sensitivity values between 80-90%. The qualitative sensitivity ranged from 1% to over 50% and was dependent on the size of the neoplastic clone and the sample DNA used. These findings illustrate that inclusion of high-throughput sequencing data for primer design can be a useful tool to guide primer design and optimization. This strategy could be applied to other antigen receptor loci or species to further improve veterinary clonality assays

Primary ciliary dyskinesia with situs inversus totalis, hydrocephalus internus and cardiac malformations in a dog.

A nine-month-old golden retriever bitch was presented with exercise intolerance and recurrent nasal discharge. Based on clinical, radiographic and ultrasonographic examination, a diagnosis of rhinitis, situs inversus totalis and tricuspid valve insufficiency was established. The results of video- and electron microscopy studies of the respiratory epithelium were compatible with primary ciliary dyskinesia (PCD). However, no evidence of a primary ultrastructural defect of the cilia was found. The dog was euthanased because of the poor prognosis. At necropsy, a hydrocephalus internus and a subaortic stenosis were additionally diagnosed. PCD, in combination with situs inversus, has been previously reported in golden retrievers, but without a concomitant hydrocephalus internus. Furthermore, concomitant occurrence of internal cardiac malformation and PCD has not previously been reported in the dog