Effects of dobutamine on cardiovascular function and oxygen delivery in standing horses

Dobutamine is routinely used to improve cardiovascular function in anaesthetized horses. However, dobutamine in conscious horses is insufficiently investigated. Ten research horses that were already instrumented for a preceding trial were included into the study. Cardiovascular variables were recorded and blood samples taken after instrumentation (Baseline), before starting dobutamine and after 10 min of dobutamine infusion (2 µg kg⁻¹ min⁻¹). A significant increase in systemic blood pressure, mean pulmonary artery pressure and right atrial pressure, and a decrease in heart rate were observed with dobutamine compared with baseline measurements. Arterial and mixed venous haemoglobin and oxygen content, as well as mixed venous partial pressure of oxygen increased. No significant changes in cardiac output, stroke volume, systemic vascular resistance, arterial partial pressure of oxygen, or oxygen consumption, delivery and extraction ratio were detected. Concluding, dobutamine increased systemic blood pressure without detectable changes in stroke volume, cardiac output or systemic vascular resistance in conscious horses.     

Evaluation of sugar beet pulp efficiency for improving the retention of copper in stormwater basin

Purpose

Sugar beet pulp (SBP) has been shown to be a promising low-cost sorbent for the removal of metals from contaminated waters. The objective of this study was to investigate the impact of SBP addition to horizontal-flow gravel filters in increasing the copper (Cu) retention ability of stormwater basins.

Material and methods

Small-scale gravel filters filled with 6 kg of a sand–sediment mix (SS) were used to experimentally treat Cu-contaminated water under conditions that represented an intense storm event. Sugar beet pulp efficiency was assessed by adding 100 g of raw SBP. Two ways of applying SBP were tested: (1) mixed with SS into the gravel filter or (2) packed at the outlet in a PVC column. Eluates were characterized by their volume, pH, Cu and dissolved organic carbon (DOC) concentrations.

Results and discussion

When placed at the outlet, SBP fixed 73 % of the Cu remaining in solution and increased the overall retention capacity of the gravel filter to 99.4 %. Conversely, when SBP was mixed with SS, the outflowing water carried higher concentrations of Cu and DOC. Complementary batch experiments underlined the crucial role of DOC in the decline of Cu sorption ability observed when SS and SBP were mixed. Geochemical calculations suggested that DOC (assumed to be pectins) promotes the mobilisation of Cu from SS by complexing it in porewater.

Conclusions

Accompanied with careful guidance, SBP has the potential of removing dissolved Cu from contaminated water in gravel filters. Protocols for SBP preparation and conditions of use should be established so as to promote its sorption efficiency and decrease its release of Cu-complexing compounds like pectins.     

ASSESSMENT OF OVARIAN CHANGES AROUND OVULATION IN BITCHES BY ULTRASONOGRAPHY, LAPAROSCOPY AND HORMONAL ASSAYS

To identify the time characteristics of ovulation, 5 bitches were evaluated during heat by ultrasonography, laparoscopy and hormonal assay. Blood collections for progesterone and oestradiol 17-β assys and ultrasonography were performed every day and laparoscopy every other day. At ultrasonography, ovaries appeared as anechoic structures about 5 days before the estimated LH peak and gradually increased in size. The greatest changes were observed between days 2 and 4 post-LH peak: echogenicity varied greatly from one animal to another and from one day to the following going from totally anechoic to mixed hypo and hyperechogenicity. Then from day 6, ovaries always appeared as hypoechoic structures assimilated to corpora lutea. At laproscopy, small follicies were seen as early as day 10 before the LH peak. Their size slowly increased to become large protubering follicies around the day of LH peak (day 0). At day 1, corpra luta were observed for the first time and were present in all animals by day 5. During that period preceeding day 5, some ovaries had both corpora lutea and follicies clearly visible on their surface. In one animal, haemorrhagic foci were observed at day 3. Neither ultrasonography, nor laparoscopy allowed precise determination of the time of ovulation. Indeed, follicle collapses was never observed, but changes in echogenicity and in the appearance of the ovaries observed by laparoscopy, suggested that ovulation occurred between days 2 and 4 when progestrone concentrations were 12.6 ± 6.2 and 32.1 ± 10.9 nmol/L, respectively.     

The pathogenesis of paraesophageal empyema in dogs and constancy of radiographic and computed tomography signs are linked to involvement of the mediastinal serous cavity

The mediastinal serous cavity is a normal anatomic space in the caudal mediastinum. Aims of this anatomic and case series study were to describe the signs of pathologic expansion of the mediastinal serous cavity observed during computed tomography (CT), review the underlying anatomy, perform a literature review, and evaluate the medical records of several dogs with mediastinal serous cavity empyema (paraesophageal empyema). The mesothelial lined mediastinal serous cavity is a cranial extension of the omental bursa, separated from the peritoneal cavity by the diaphragm, in the dorsal part of the caudal mediastinum, to the right of the esophagus, between the heart base and diaphragm. In five adult, large‐breed dogs with surgically and histologically confirmed paraesophageal empyema, macroscopic plant material was found at surgery in two dogs, adherence to adjacent lung was present in three different dogs, accessory lobectomy was performed in two dogs with subacute‐chronic pyogranulomatous pneumonia, and one dog had concurrent pyothorax and mediastinitis, but none had esophageal abnormalities. This study expands our understanding of the pathogenesis and basis for the imaging appearance of paraesophageal empyema in dogs by clarifying the underlying anatomic structures that direct development of this condition. The term empyema accurately describes this condition because the purulent material accumulates within an existing body cavity. The study also provides initial evidence that the development of paraesophageal empyema might be due to local extension of lung disease, such as foreign body migration or pneumonia. Computed tomography was helpful for diagnosis, assessing size, and determining the spread of disease.     

CHLAMYDIA AVIUM DETECTION FROM A RING-NECKED PARAKEET (PSITTACULA KRAMERI) IN FRANCE

The crossing of host species barriers, through the spreading populations of introduced pet animals that become established in the wild, sets the stage for zoonotic pathogen (re)emergence. A literature review on pathogens that are hosted by the ring-necked parakeet (Psittacula krameri), a worldwide introduced pet, highlighted local infections of captive birds by chlamydial agents with high sanitary risk for human health in its introduced range. We searched for these pathogens through cloacal swabs collected from 85 individuals in an invasive population established in the suburban areas of Paris (Ile-de-France) from 5 localities during the winter seasons between 2011 and 2014. Based on quantitative PCR analysis, Chlamydiaceae shedding was detected at too low levels for species identification in 5 birds, but 1 parakeet (found dead) was positive for Chlamydiaceae typed as Chlamydia avium. The only known hosts recorded for C. avium in Europe are feral pigeons (Columba livia) and captive psittacines. This result raises the question of the sanitary risks associated with new pathogen transmission from exotic pets released in the wild, which could locally affect birds and potentially people who feed birds.     

High lysyl oxidase expression is an indicator of poor prognosis in dogs with cutaneous mast cell tumours

Mast cell tumour (MCT) is one of the most frequent skin tumours in dogs. Due to their unpredictable biological behaviour, MCTs often cause several therapeutic frustrations, leading to investigation regarding prognostic markers. Lysyl oxidase (LOX) is an enzyme that promotes extracellular matrix stability and contributes to cell migration, angiogenesis and epithelial-mesenchymal transition. Its expression positively correlates with poor prognoses in several human and canine mammary cancers. The aim of this study was to characterise the immunohistochemical expression of LOX in MCT samples and compare it with histological grading and post-surgical survival. Twenty-six tumours were submitted to immunohistochemistry for LOX expression evaluation. All samples were positive for LOX, with variable percentages of cytoplasmic and nuclear positivity. Cytoplasmic positivity was significantly higher in high-grade MCTs (P = .0297). Our results indicate that high expression of cytoplasmic LOX in neoplastic mast cells is an indicator of poor prognosis for canine cutaneous MCTs.     

MRI of the live fish brain at 3 Tesla: Feasibility,technique and interspecies anatomic variations

Advances in aquatic animal medicine and continued growth of the fish hobbyist and aquaculture communities have led to a developing interest in antemortem diagnostic imaging of aquatic species. The aims of this prospective, pilot study were to determine whether advanced neuroimaging can be safely achieved in live fish using clinically available equipment, to optimize imaging parameters, and to develop a comparative MRI atlas of a few fish species of economic or research value. Two each of channel catfish (Ictalurus punctatus), koi (Cyprinus rubrofuscus), and grass carp (Ctenopharyngodon idella) of at least 30 cm in length were individually anesthetized for 3 Tesla (3T) magnetic resonance imaging (MRI) of the brain. All fish achieved an adequate anesthetic level for prolonged immobilization during imaging. Diagnostic quality images were obtained for all subjects; however, the spatial resolution was maximized with larger fish. Imaging protocols were optimized for standard neuroimaging sequences. Additionally, inversion times for fluid-attenuation inversion recovery (FLAIR) sequences were adapted to the naturally high protein content of fish pericerebral fluid. Following imaging, the fish successfully recovered from anesthesia, were humanely euthanized, and were immediately processed to assess brain histopathology. Necropsy confirmed the sex and health status of each fish. A limited comparative MRI atlas was created of the brains of these species for clinical reference. Findings from the current study supported the use of 3T MRI as an adjunct diagnostic test for fish with suspected neurologic disease and provided a limited anatomic atlas of the teleost brain for use as a reference.     

Influence of eggs on the aroma composition of a sponge cake and on the aroma release in model studies on flavored sponge cakes

The use of solvent-assisted flavor evaporation extraction (SAFE) and purge and trap in Tenax allowed the identification of more than 100 volatile compounds in a sponge cake (SC-e). Gas chromatography-olfactometry (GC-O) of the SAFE extracts of crumb and crust were achieved in order to determine the most potent odorants of SC-e. The change in the traditional dough formulation of SC-e in which eggs were substituted by baking powder (SC-b) as the leavening agent produced important changes in some key aroma compounds. The release curves of some aroma compounds-some of them generated during baking and others added in the dough-were followed by cumulative headspace analysis. In the flavored SC-b, the aroma release curves showed a plateau after 15 min of purge, while the release increased proportionally with the purge time in the flavored SC-e. In general, except for some of the aroma compounds with the highest log P values, the rate of release of most of the added and generated aroma compounds was significantly influenced by the changes in the cake formulation. The higher rates of release found for the aroma compounds in SC-b could contribute to explain its rapid exhaustion of aroma compounds in the purge and trap experiments and might lead to poorer sensorial characteristics of this cake during storage.     

Hypothalamic mTOR signaling regulates food intake

The mammalian Target of Rapamycin (mTOR) protein is a serine-threonine kinase that regulates cell-cycle progression and growth by sensing changes in energy status. We demonstrated that mTOR signaling plays a role in the brain mechanisms that respond to nutrient availability, regulating energy balance. In the rat, mTOR signaling is controlled by energy status in specific regions of the hypothalamus and colocalizes with neuropeptide Y and proopiomelanocortin neurons in the arcuate nucleus. Central administration of leucine increases hypothalamic mTOR signaling and decreases food intake and body weight. The hormone leptin increases hypothalamic mTOR activity, and the inhibition of mTOR signaling blunts leptin's anorectic effect. Thus, mTOR is a cellular fuel sensor whose hypothalamic activity is directly tied to the regulation of energy intake.