Transcriptomic markers meet the real world: finding diagnostic signatures of corticosteroid treatment in commercial beef samples.

BACKGROUND: The use of growth-promoters in beef cattle, despite the EU ban, remains a frequent practice. The use of transcriptomic markers has already proposed to identify indirect evidence of anabolic hormone treatment. So far, such approach has been tested in experimentally treated animals. Here, for the first time commercial samples were analyzed. RESULTS: Quantitative determination of Dexamethasone (DEX) residues in the urine collected at the slaughterhouse was performed by Liquid Chromatography-Mass Spectrometry (LC-MS). DNA-microarray technology was used to obtain transcriptomic profiles of skeletal muscle in commercial samples and negative controls. LC-MS confirmed the presence of low level of DEX residues in the urine of the commercial samples suspect for histological classification. Principal Component Analysis (PCA) on microarray data identified two clusters of samples. One cluster included negative controls and a subset of commercial samples, while a second cluster included part of the specimens collected at the slaughterhouse together with positives for corticosteroid treatment based on thymus histology and LC-MS. Functional analysis of the differentially expressed genes (3961) between the two groups provided further evidence that animals clustering with positive samples might have been treated with corticosteroids. These suspect samples could be reliably classified with a specific classification tool (Prediction Analysis of Microarray) using just two genes. CONCLUSIONS: Despite broad variation observed in gene expression profiles, the present study showed that DNA-microarrays can be used to find transcriptomic signatures of putative anabolic treatments and that gene expression markers could represent a useful screening tool.

Post-mortem investigations on a leatherback turtle Dermochelys coriacea stranded along the Northern Adriatic coastline.

Leatherback sea turtles Dermochelys coriacea are regularly reported in the Mediterranean Sea but rarely reach the northern Adriatic Sea. In the summer of 2009, a well-preserved carcass of an adult female of this species was found dead along the coast of Lido di Venezia. A complete necropsy was carried out, along with evaluation of levels of tissue trace elements. The the post-mortem revealed acute severe bacterial gastroenteritis caused by Photobacterium damselae ssp. piscicida, an opportunistic agent that infected an apparently debilitated animal weakened by ingested plastic debris. High levels of heavy metals (Hg, Pb, Cd and As) found in the liver and kidneys might have contributed to the animal's demise. These findings support previous indications that marine debris is one of the major threats to marine animals, particularly for critically endangered species such as the leatherback turtle.

Cardiovascular flukes (Trematoda: Spirorchiidae) in Caretta caretta Linnaeus, 1758 from the Mediterranean Sea.

BACKGROUND: The northern Adriatic Sea represents one of the most important neritic foraging grounds for the loggerhead sea turtle Caretta caretta L. in the Mediterranean Sea. Four genera of blood flukes with variable prevalence and pathogenic impact have been reported worldwide in this species. Hapalotrema Looss, 1899 and Amphiorchis Price, 1934 are the only two genera reported in Mediterranean waters; however, updated data describing spirorchiidiasis in the central and eastern Mediterranean and infection prevalence are still lacking. This work aimed to investigate the presence and pathology of spirorchiidiasis in C. caretta in the Mediterranean Sea. METHODS: One hundred sixty-eight animals stranded along the northwestern Adriatic coast between 2009 and 2015 were submitted to necropsy and subsequent analyses for the detection of adult flukes, detection of eggs in the faeces and spleen and histopathology. Molecular analyses were carried out on hosts (mitochondrial D-loop) and parasites (28S gene and ITS2 spacer) to trace the turtle origins and identify the fluke phylogenetic relationships. RESULTS: Spirorchiidiasis was detected in 16.7% of the animals. Hapalotrema mistroides (Monticelli, 1899) and Neospirorchis sp. were found in twenty-six and ten cases, respectively. Adult flukes were found in six cases, while eggs were detectable through copromicroscopic examination for all infected turtles, and the results for the detection of eggs in the spleen agreed with the copromicroscopic analysis. Only mild lesions were observed. Eggs of types 1 and 3 were grossly visible in the gastrointestinal mucosa, vasculitis was rarely observed in the heart and great vessels, and multifocal granulomas were widespread in the tissues. Molecular identification unambiguously assigned the spirorchiid samples to H. mistroides and Neospirorchis sp. Genetic characterization of loggerhead mtDNA pointed to a Mediterranean origin of the turtle hosts. CONCLUSION: This survey provides new data on the spread of spirorchiidiasis in the Mediterranean loggerhead sea turtle population and reports for the first time the presence of Neospirorchis spp. in this basin. The infections did not have a causal effect on the death nor a strong impact on the general health status of the animals.

In vivo and in vitro development of mouse pancreatic beta-cells in organotypic slices.

Taking tissue slices of the embryonic and newborn pancreas is a novel approach for the study of the perinatal development of this gland. The aim of this study was to describe the morphology and physiology of in vivo and in vitro developing beta-cells. In addition, we wanted to lay a foundation for the functional analysis of other pancreatic cells, either alone or as part of an integrative pancreatic physiology approach. We used cytochemistry and light microscopy to detect specific markers and the whole-cell patch-clamp to assess the function of single beta-cells. The insulin signal in the embryonic beta-cells was condensed to a subcellular compartment and redistributed throughout the cytosol during the first 2 days after birth. The hormone distribution correlated well with the development of membrane excitability and hormone release competence in beta-cells. Endocrine cells survived in the organotypic tissue culture and maintained their physiological properties for weeks. We conclude that our preparation fulfills the criteria for a method of choice to characterize the function of developing pancreas in wild-type and genetically modified mice that die at birth. We suggest organotypic culture for in vitro studies of the development and regeneration of beta-cells.