SUMMARYIt is seldom the primary tumour that proves fatal in cancer, with metastasis the fundamental pathological process for disease progression. Upregulation of Mena, a member of the evolutionarily conserved Ena/VASP family of actin cytoskeletal regulators, promotes metastasis and invasive motility of breast cancer cells in vivo. To complement in vitro studies of Ena/VASP function in fibroblasts, we manipulated levels of Ena, the Drosophila homologue of Mena, in migrating embryonic macrophages (haemocytes). Consistent with data from fibroblasts in vitro, Ena localises to regions of actin dynamics within migrating haemocytes, stimulates lamellipodial dynamics and positively regulates the number and length of filopodia. However, whereas Ena overexpression in fibroblasts reduces migration speeds, overexpressing Ena in haemocytes leads to a dramatic increase in migration speeds, more closely resembling the increased motility of breast cancer cells that overexpress Mena. We provide evidence that this key difference is due to spatial constraints imposed on cells within the three-dimensional environment of the embryo; this might explain how Mena can be used to promote aggressive migratory behaviour during cancer progression.

Objectives The aim of this study was to report the incidence of anaesthetic complications associated with feline bronchoscopy. Methods This was a retrospective analysis of anaesthetic records and electronic case logs of feline bronchoscopies at two university hospitals (centres B and L) between January 2013 and December 2015. A two-tailed Fisher’s exact test was used for comparison of variables and outcomes between centres. Results Seventy-nine cases were included. Desaturation (SpO2 <90%) was the most frequently encountered complication, reported in 24 cats (30.3%); centre B reported significantly less desaturation than centre L (22.4% vs 52.4%; P = 0.014). The use of an endotracheal tube or laryngeal mask airway resulted in a lower incidence of desaturation (22.9% vs 22.2%) than the use of a tracheal catheter through which oxygen was insufflated (48.0%). The latter method was associated with an increased incidence of desaturation ( P = 0.034). Patients to which terbutaline was administered had a lower incidence of desaturation (27.5%) than those that did not receive it (35.7%), although this was not statistically significant ( P = 0.46). Airway management method and the use of terbutaline differed significantly between centres, as did the profile of complications. Pneumothorax was encountered in two cats (2.5%) and cardiac arrest resulting in the death in one of these cats (1.3%). Conclusions and relevance Desaturation is a frequently encountered complication during and after bronchoscopy. Airway management method and the use and timing of terbutaline warrant prospective evaluation for their role in decreasing the incidence of desaturation. Bronchoscopy is a high-risk procedure with frequent requirement for post-procedure oxygen supplementation. Pneumothorax and cardiac arrest are potential complications.

A four-year-and-three-month-old Jack Russell terrier presented for investigation of acute-onset paraplegia, with an MRI performed under general anaesthesia. Following administration of a gadobutrol contrast medium, apnoea, cyanosis, resistance to ventilation, hypotension and tachycardia were observed. An anaphylactic reaction was suspected, characterised by severe bronchoconstriction and cardiovascular collapse. This was treated with multiple isotonic crystalloid fluid boluses, intermittent positive pressure ventilation, terbutaline and cessation of general anaesthesia. Following recovery from general anaesthesia, continuous positive airway pressure and later high-flow nasal oxygen therapy were needed to treat severe hypoxaemia. Treatment of the acute anaphylactic reaction was successful; however, the dog was euthanased due to progressive neurological disease.

Cell migration has been studied extensively in vitro, however, fewer studies address this subject in vivo. Our aim is to determine in vivo, the role of the actin regulatory protein, Ena. To enable this we are studying Drosophila hemocytes in the developing embryo. Hemocytes are the primary immune cells of Drosophila and during development they follow stereotyped pathways to distribute throughout the embryo. Using the Gal4UAS system to express GFP specifically in hemocytes allows us to visualize the migrating hemocytes using the confocal microscope. This system is also used to overexpress Ena or interfere with its function. Here we show that Ena localizes to the

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