Characterization of the ablation zones produced by three commercially available systems from a single vendor for radiofrequency thermoablation in an ex vivo swine liver model.

BACKGROUND: Radiofrequency Ablation (RFA) is rarely performed in veterinary medicine. A rationale exists for its use in selected cases of canine liver tumours. RFA induces ablation zones of variable size and geometry depending on the technique used and on the impedance of the targeted organ. OBJECTIVES: (a) to describe the geometry and reproducibility of the ablation zones produced by three commercially available systems from a single company, using isolated swine liver parenchyma as a model for future veterinary applications in vivo; (b) to study the effects of local saline perfusion into the ablated parenchyma through the electrode tip and of single versus double passage of the electrode on size, geometry and reproducibility of the ablation zones produced. METHODS: Size, and geometry of ablation zones reproduced in six livers with one cooled and perfused (saline) and two cooled and non-perfused systems, after single or double passage (n = 6/condition), were assessed macroscopically on digitalized images by a blinded operator. Longitudinal and transverse diameters, equivalent diameter, estimated volume and roundness index were measured. Reproducibility was assessed as coefficient of variation. RESULTS AND CONCLUSIONS: Ablation zone reproducibility was higher when expressed in terms of ablation zone diameters than estimated volume. Local saline perfusion of the parenchyma through the electrode tip during RFA increased the ablation zone longitudinal diameter. Ablation zone estimated volume increased with saline perfusion only when double passage was performed. These data may provide useful information for those clinicians who intend to include RFA as an additive tool in veterinary interventional radiology.

Fatal Leucocytozoon Infection in a Captive Grey-headed Parrot (Poicephalus robustus suahelicus).

A necropsy was conducted on a female grey-headed parrot (Poicephalus robustus suahelicus) that died following signs of depression, ruffled feathers, and inappetence. Microscopic examination revealed the presence of hemoprotozoa in the liver. A nested polymerase chain reaction (PCR), targeting the mitochondrial cytochrome b gene of Haemoproteus species, Plasmodium species, and Leucocytozoon species, was performed on frozen tissue samples collected at necropsy. The hemoprotozoa were identified by PCR analysis as Leucocytozoon species. Hemoprotozoa are rarely reported in African parrots, and this is the first report of a Leucocytozooon species infection in a Poicephalus robustus suahelicus.

Gene expression profile associated with thymus regeneration in dexamethasone-treated beef cattle.

Glucocorticoids (GCs) are illegally used as growth promoters in cattle, and the analytical methods officially applied most likely underestimate the precise frequency of the abuse. As a side effect, the administration of GCs causes fat infiltration, apoptosis, and atrophy of the thymus. However, gross and histological observations carried out previously showed that the thymus preserves an intrinsic ability to regenerate. The aim of this work was to study the transcriptional effects of GCs on genes likely involved in regeneration of the epithelial cell network in the cervical and thoracic thymus of beef cattle treated with dexamethasone (DEX) or prednisolone (PRD) in comparison with a control group. Moreover, the ratio of bax/bcl2 genes was examined to verify a possible antiapoptotic activity occurring at the same time. In the cervical thymus, DEX administration increased the gene expression of c-myc (P < 0.01), tcf3 (P < 0.05), tp63 (P < 0.01), and keratin 5 (krt5; P < 0.01). In the thoracic thymus of DEX-treated cattle, the gene expression of tcf3 (P < 0.01), tp63 (P < 0.01), and krt5 (P < 0.05) was increased. These results suggested that thymic regeneration is underway in the DEX-treated animals. However, the bax/bcl2 ratio was decreased in both cervical and thoracic thymus of DEX-treated cattle (P < 0.01 and P < 0.05, respectively), showing an antiapoptotic effect through the mitochondrial pathway. Conversely, PRD administration caused no change in the expression of all considered genes. These results sustain the hypothesis that regeneration occurs in the thymus parenchyma 6 d after the DEX treatment was discontinued. This hypothesis is also supported by the absence of alterations in the thymus of PRD-treated beef cattle. Indeed, previous studies showed the inability of PRD to induce macroscopic and microscopic lesions in the thymus. Therefore, in this context, it is not surprising that PRD induced no alteration of genes involved in the regeneration pathway.

Occlusive mycotic tracheobronchitis and systemic Alphaherpesvirus coinfection in a free-living striped dolphin Stenella coeruleoalba in Italy.

A juvenile female striped dolphin Stenella coeruleoalba live stranded on 4 March 2016 at Alassio, western Ligurian Sea coast, Italy. The dolphin died shortly after stranding, and a complete postmortem examination was performed. Necropsy revealed severe tracheal occlusion and unilateral bronchial stenosis with luminal accumulation of abundant green-yellow mucous-gelatinous material. Histological features suggestive of tracheobronchial aspergillosis were observed. Cultures of lung tissue and tracheo-bronchial exudate isolated Aspergillus fumigatus, identified by a Microseq D2 LSUrDNA fungal sequencing kit. A pan-Herpesvirus nested-PCR assay on frozen samples obtained from multiple organs was positive. Phylogenetic analysis on the partial DNA polymerase gene revealed that the striped dolphin isolate was closely related to known cetacean Alphaherpesvirus sequences from the same host species. Attempted virus isolation was unsuccessful. The tissue levels of different persistent organic pollutants and the toxicological stress, evaluated using a theoretical model, showed a severely impaired immune response. This study reports the first case of occlusive mycotic tracheobronchitis in a free-living cetacean and the first molecular identification of an Alphaherpesvirus in a free-ranging striped dolphin stranded on the coast of Italy.

Development and Application of a Screening Method of Absolute Quantitative PCR To Detect the Abuse of Sex Steroid Hormone Administration in Male Bovines.

A methodology for the absolute quantification of regucalcin gene through quantitative PCR was set up to confirm that the decrease of regucalcin gene expression in the testis is an effective biomarker for tracing sex steroid hormone treatment in bovine husbandry. On the basis of TaqMan technology, an external standard curve was generated. Using in vivo experiments, a ROC curve was developed to calculate the criterion value, specificity, and sensitivity for this potential biomarker. Then, regucalcin gene expression was assessed in veal calves and beef intended for human consumption. In 11 of 54 calves and in 5 of 70 beef cattle the regucalcin gene was expressed under their respective cutoff. Additionally, a mild decrease of regucalcin protein expression was revealed by immunohistochemistry in subjects tested positive via qPCR. These preliminary results suggest that this transcriptomics test may be employed as a novel diagnostic screening tool, improving significantly the overall efficacy of food control.

Morphological Examination and Transcriptomic Profiling To Identify Prednisolone Treatment in Beef Cattle.

In livestock production corticosteroids are licensed only for therapy; nevertheless, they are often illegally used as growth promoters. The aim of this study was to identify morphological or biomolecular alterations induced by prednisolone (PDN) in experimentally treated beef cattle, because PDN and its metabolites are no longer detectable by LC-MS/MS methods in biological fluids. Moreover, PDN does not induce any histological alterations in the thymus, different from dexamethasone treatments. Therefore, a marker of illicit treatment for this growth promoter could be useful. Eight male Italian Friesian beef cattle were administered prednisolone acetate 30 mg day-1 per os for 35 days, and seven beef cattle represented the control group. Six days after drug withdrawal, the animals were slaughtered. Morphological and morphometric modifications were evaluated in the epididymis and testis, whereas transcriptomic changes induced by PDN administration were investigated in peripheral blood mononuclear cells (PBMCs) at different sampling times and in skeletal muscle and testis sampled at slaughtering. In the epididymis, spermatozoa number decreased in PDN-treated animals, and in some cases they were totally absent. Correspondingly, in the testis of treated animals, down-regulation for serine/threonine kinase 11 (STK11) gene expression was detected (p < 0.01). DNA microarray analysis revealed a total of 133 differentially expressed genes in skeletal muscle and testis, and 907 and 1416 in PBMCs after 33 days of treatment and at slaughtering, respectively. Histological investigations on epididymal content could represent a promising marker for PDN treatment in beef cattle and could be used as a screening method to identify animals worthy of further investigation with official methods. Moreover, the clear transcriptomic signature of PDN treatment evidenced in PBMCs supported the possibility of using this matrix to monitor the illicit treatment in vivo during ranching.

Pentalogy of Fallot in a captive Siberian tiger (Panthera tigris altaica).

A 2-yr-old male Siberian Tiger (Panthera tigris altaica) died during a fight with a conspecific. At necropsy, significant abnormalities included severe cardiomegaly with cardiac malformations consisting of a large atrial septal defect, a membranous ventricular septal defect, overriding aorta, and stenosis of the pulmonary valve with secondary concentric hypertrophy of the right ventricle. Endocardiosis of the mitral valve was also noted. To the authors' knowledge, this is the first report of a pentalogy of Fallot in a large felid that resulted in sudden death.