Residents and patients benefit from surgical simulation on a live porcine model, could we consider it as ethical?

INTRODUCTION: The objective was to evaluate, by self-questionnaire, the feeling of participants in surgical training sessions on a live porcine model. METHODS: A computerized questionnaire (GoogleForm ©) was sent to the members of the French Association of Urologists-in-Training (AFUF) (fellows and residents). Only questionnaires from Urologists-in-training who had participated in surgical training sessions were included. The sessions consisted of performing surgeries such as laparoscopic nephrectomies or laparoscopic cystectomies. RESULTS: Overall, 198 met the inclusion criteria. A total of 36.4% (72/198) of the participants were fellows and 63.6% (126/198) were residents. According to the participants, the main interest of sessions was to be able to train for emergency situations. A total of 79.8% (158/198) of the participants wanted surgical simulation to become compulsory. To their opinion, the main advantage of surgical simulation on a live porcine model was: technical progress in 87.4% (173/198) of cases. A total of 13.1% (26/198) of the participants found it was unethical to perform the first technical procedures on live animal models. A total of 65.7% (130/198) of the participants considered that there is currently no system of substitution. CONCLUSION: For the participants, surgical training on a live porcine model allows technical progress while training for serious emergency situations. Surgeons and patients could benefit from this risk-free mock surgical scenario. LEVEL OF EVIDENCE: 3.

Assessment of a blood preservation protocol for use in ferrets before transfusion.

Blood transfusion has been described in ferrets as a treatment for oestrus-associated anaemia and as a life-saving therapy following trauma, iatrogenic (usually surgery-induced) anaemia, autoimmune haemolytic anaemia and pure red cell aplasia. Although blood banking is a common method for storage of feline and canine blood it is not currently done with ferret blood. The aim of this study was to determine the shelf-life of ferret blood using the anticoagulant citrate-phosphate-dextrose-solution with adenine (CPDA). Two male ferrets were used as blood donors. From each ferret, 6 ml of blood was taken from the cranial vena cava and stored in 10 ml polyethylene terephthalate (PET) blood tubes containing 1 ml of CPDA solution. Blood was taken from each ferret once per month for five months. These 10 blood samples were stored in a laboratory refrigerator at 4°C for four weeks. Biochemical (glucose, pH, lactate, potassium, sodium) and haematological (haematocrit, light microscopic blood smear examination) analyses were performed on the stored blood at days 0, 7, 14, 21 and 28. Biochemical analyses revealed a progressive decrease from day seven in the stored blood pH, glucose and sodium, with a concomitant increase in lactate and potassium. These results are attributable to the ongoing metabolism and deterioration of the red blood cells (RBC) while in storage, and are more rapid than described for human or canine stored blood. Haematological analyses revealed a progressive elevation of the haematocrit due to the appearance of hypochromic red blood cells and echinocytes beginning at day 7. Haemolysis was observed in the microhaematocrit capillary tube sample by day 21, and microscopic clots were visible on the blood smear by day 28. The low blood pH and the appearance of many hypochromic RBCs and some echinocytes from day 7 in CPDA-stored ferret blood, suggest stored ferret blood has a short shelf-life when compared with stored human or canine blood. We recommend that ferret blood stored in CPDA should not be used for transfusion after seven days of storage at 4°C.

Tolerogenic dendritic cells actively inhibit T cells through heme oxygenase-1 in rodents and in nonhuman primates.

Clinical translation of dendritic cell (DC)-based cell therapy requires preclinical studies in nonhuman primates (NHPs). The aim of this work was to establish the in vitro conditions for generation of NHP tolerogenic DCs (Tol-DCs), as well as to analyze the molecular mechanisms by which these cells could control an immune response. Two populations of NHP bone marrow-derived DCs (BMDCs) were obtained: adherent and nonadherent. Although both populations displayed a quite similar phenotype, they were very different functionally. We characterized the adherent BMDCs as Tol-DCs that were poor stimulators of T cells and actively inhibited T-cell proliferation, whereas the nonadherent population displayed immunogenic properties in vitro. Interestingly, the anti-inflammatory and immunosuppressive enzyme heme oxygenase-1 (HO-1) was up-regulated in Tol-DCs, compared to the immunogenic BMDCs. We demonstrated that HO-1 mediates the immunosuppressive properties of Tol-DCs in vitro (in NHPs and rats) and that HO-1 is involved in the in vivo tolerogenic effect of Tol-DCs in a rat model of allotransplantation. In conclusion, here we characterized the in vitro generation of NHP Tol-DCs. Furthermore, we showed for the first time that HO-1 plays a role in the active inhibition of T-cell responses by rat and NHP Tol-DCs.

Oral administration of doxycycline allows tight control of transgene expression: a key step towards gene therapy of retinal diseases.

Gene transfer of neurotrophic or antiangiogenic factors has been shown to improve photoreceptor survival in retinal degenerative disorders (that is retinitis pigmentosa) and to prevent neovascularization in retinal vascular diseases (that is age-related macular degeneration, diabetic retinopathy). Expression of such neurotrophic or antiangiogenic factors after gene transfer requires the use of a regulatory system to control transgene expression to avoid unwanted side effects in cases of overexpression. In a previous study, we demonstrated that rAAV-mediated gene transfer of the tetracycline-regulatable (tetR) system allows transgene regulation in the retina of nonhuman primates after intravenous administration of doxycycline (Dox). The purpose of this study was to evaluate oral administration of Dox to control transgene expression in the retina, since the pharmacokinetics after oral administration of the inducer drug represent a key factor when considering advancing to clinical trials. We report on the outcome of this evaluation and demonstrate that oral administration of Dox at a dose that is clinically used in humans (5 mg kg(-1) per day) is capable to continuously induce transgene expression in all macaques tested for 6 months. Moreover, control of transgene expression persists up to 4 years post-subretinal injection, with maximal induced levels of transgene product remaining stable over time.

Ureteral sarcoma in a dog.

A ureteral sarcoma was diagnosed in a nine-year-old Weimaraner dog with gross haematuria, severe unilateral hydronephrosis, and hydroureter. Treatment consisted of unilateral nephrectomy and ureterectomy. This case was compared with 14 other ureteral tumours reported in the veterinary literature. Only three previous reports concerned a malignant ureteral tumour. Urinary tract neoplasms mainly involve the bladder and the kidney, and more rarely the urethra. The purpose of this paper is to report a rare case of malignant ureteral tumour in a dog.

Restoration of vision in RPE65-deficient Briard dogs using an AAV serotype 4 vector that specifically targets the retinal pigmented epithelium.

Previous studies have tested gene replacement therapy in RPE65-deficient dogs using recombinant adeno-associated virus 2/2 (rAAV2/2), -2/1 or -2/5 mediated delivery of the RPE65 gene. They all documented restoration of dark- and light-adapted electroretinography responses and improved psychophysical outcomes. Use of a specific RPE65 promoter and a rAAV vector that targets transgene expression specifically to the RPE may, however, provide a safer setting for the long-term therapeutic expression of RPE65. Subretinal injection of rAAV2 pseudotyped with serotype 4 (rAAV2/4) specifically targets the RPE. The purpose of our study was to evaluate a rAAV2/4 vector carrying a human RPE65cDNA driven by a human RPE65 promoter, for the ability to restore vision in RPE65-/- purebred Briard dogs and to assess the safety of gene transfer with respect to retinal morphology and function. rAAV2/4 and rAAV2/2 vectors containing similar human RPE65 promoter and cDNA cassettes were generated and administered subretinally in eight affected dogs, ages 8-30 months (n = 6 with rAAV2/4, n = 2 with rAAV2/2). Although fluorescein angiography and optical coherence tomography examinations displayed retinal abnormalities in treated retinas, electrophysiological analysis demonstrated that restoration of rod and cone photoreceptor function started as soon as 15 days post-injection, reaching maximal function at 3 months post-injection, and remaining stable thereafter in all animals treated at 8-11 months of age. As assessed by the ability of these animals to avoid obstacles in both dim and normal light, functional vision was restored in the treated eye, whereas the untreated contralateral eye served as an internal control. The dog treated at a later age (30 months) did not recover retinal function or vision, suggesting that there might be a therapeutic window for the successful treatment of RPE65-/- dogs by gene replacement therapy.

Systemic xanthomatosis associated with hyperchylomicronaemia in a cat.

We report a case of systemic xanthomatosis in a 4-month-old domestic cat. The kitten presented with multiple cutaneous lesions and 'cream tomato soup' coloured blood. Necropsy revealed multiple, whitish, nodular lesions, compatible with xanthomas, on most of the abdominal organs (liver, spleen, kidney, adrenal glands, mesentery and colon). The diagnosis was confirmed by histopathological examination. This is the first report of granulomatous colitis associated with feline xanthomatosis.

Effect of intravenous glutamine on duodenal mucosa protein synthesis in healthy growing dogs.

To determine whether glutamine acutely stimulates protein synthesis in the duodenal mucosa, five healthy growing dogs underwent endoscopic biopsies of duodenal mucosa at the end of three 4-h primed, continuous intravenous infusions of L-[1-13C]leucine on three separate days, while receiving intravenous infusion of 1) saline, 2) L-glutamine (800 micromol. kg-1. h-1), and 3) isonitrogenous amounts of glycine. The three infusions were performed after 24 h of fasting, a week apart from each other and in a randomized order. Glutamine infusion induced a doubling in plasma glutamine level, and glycine caused a >10-fold rise in plasma glycine level. During intravenous infusions of [13C]leucine, the plasma leucine labeling attained a plateau value between 3.22 and 3.68 mole % excess (MPE) and [13C]ketoisocaproate ([13C]KIC) of 2.91-2. 84 MPE; there were no significant differences between glutamine, glycine, and saline infusion days. Plasma leucine appearance rate was 354 +/- 33 (SE), 414 +/- 28, and 351 +/- 35 micromol. kg-1. h-1 (not significant) during glycine, saline, and glutamine infusion, respectively. The fractional synthetic rate (FSR) of duodenal mucosa protein was calculated from the rise in protein-bound [13C]leucine enrichment in the biopsy sample, divided by time and with either plasma [13C]KIC or tissue free [13C]leucine as precursor pool enrichment. Regardless of the precursor pool used in calculations, duodenal protein FSR failed to rise significantly during glutamine infusion (65 +/- 11%/day) compared either with saline (84 +/- 18%/day) or glycine infusion days (80 +/- 15%/day). We conclude that 1) plasma [13C]KIC and tissue free [13C]leucine can be used interchangeably as precursor pools to calculate gut protein FSR; and 2) short intravenous infusion of glutamine does not acutely stimulate duodenal protein synthesis in well-nourished, growing dogs.