Exploring the pathology of liver, kidney, muscle, and stomach of fledgling seabirds associated with plastic ingestion.

There remain significant gaps in knowledge about 'sub-lethal' impacts of plastic ingestion, particularly chronic impacts on cells, tissues, or organs. Few studies have applied traditional animal health tools, such as histopathology, to assess physiological damage to wildlife, with fewer still providing information on the dosage or exposure to plastics needed to elicit negative effects. Our study seeks to investigate a common hypothesis in plastic pollution research; that an increasing plastics burden will have an impact on an animal's health, examining two wild species with high levels of environmental exposure to plastic through their diet. Here we assess the histopathology of the muscle, upper digestive tract, liver and kidney of two seabird species that are known to be commonly exposed to plastic, comparing exposed and non-exposed individuals. Fledgling seabirds showed histopathological evidence of cumulative pressures such as starvation, disease, and endoparasite burden. However, we observed no evidence of chronic harm that could be explicitly linked to the plastics. We found one case of haemorrhage, reaffirming that large/sharp plastic foreign bodies may cause acute physical damage. Given the numerous interacting pressures on the health of fledging seabirds, including exposure to plastic, this study highlights the need to scrutinise plastic-animal interactions and research though a One Health lens.

SURVEILLANCE FOR CHLAMYDIA SPP. WITH MULTILOCUS SEQUENCE TYPING ANALYSIS IN WILD AND CAPTIVE BIRDS IN VICTORIA, AUSTRALIA.

Chlamydia psittaci typically infects birds and can cause outbreaks of avian chlamydiosis, but it also has the potential to cause zoonotic disease (psittacosis) in humans. To better understand the epidemiology of C. psittaci in Victoria, Australia, we conducted opportunistic sampling of more than 400 wild and captive birds presented to the Australian Wildlife Health Centre at Zoos Victoria's Healesville Sanctuary for veterinary care between December 2014 and December 2015. Samples were screened for the presence of chlamydial DNA using quantitative PCR, and positive samples were subjected to multilocus sequence typing analysis. The results showed a significantly higher prevalence of infection in captive birds (8%; 9/113) compared to wild birds (0.7%; 2/299). Multilocus sequence typing analysis revealed that C. psittaci sequence type 24 was detected in both wild and captive birds in the local region, while C. psittaci sequence type 27 was detected for the first time in an Australian avian host. The generally low prevalence of C. psittaci detection points to a generally low zoonotic risk to veterinary and support staff, although this risk may be higher when handling captive birds, where the prevalence of C. psittaci infection was almost 10-fold higher. Even with low rates of C. psittaci detection, appropriate hygiene and biosecurity practices are recommended due to the serious human health implications of infection with this pathogen.

Lateral versus anterior thoracic thrusts in the generation of airway pressure in anaesthetised pigs.

OBJECTIVE: Anterior chest thrusts (with the subject sitting or standing and thrusts applied to the lower sternum) are recommended by the Australian Resuscitation Council as part of the sequence for clearing upper airway obstruction by a foreign body. Lateral chest thrusts (with the victim lying on their side) are no longer recommended due to a lack of evidence. We compared anterior, lateral chest and abdominal thrusts in the generation of airway pressures using a suitable animal model. METHODS: This was a repeated-measures, cross-over, clinical trial of eight anaesthetised, intubated, adult pigs. For each animal, ten trials of each technique were undertaken with the upper airway obstructed. A chest/abdominal pressure transducer, a pneumotachograph and an intra-oesophageal balloon catheter recorded chest/abdominal thrust, expiratory air flows, airway and intrapleural pressures, respectively. RESULTS: The mean (SD) thrust pressures generated for the anterior, lateral and abdominal techniques were 120.9 (11.0), 135.2 (20.0), and 142.4 (27.3)cmH(2)O, respectively (p<0.0001). The mean (SD) peak expiratory airway pressures were 6.5 (3.0), 18.0 (5.5) and 13.8 (6.7)cmH2O, respectively (p<0.0001). The mean (SD) peak expiratory intrapleural pressures were 5.4 (2.7), 13.5 (6.2) and 10.3 (8.5)cmH(2)O, respectively (p<0.0001). At autopsy, no rib, intra-abdominal or intra-thoracic injury was observed. CONCLUSION: Lateral chest and abdominal thrust techniques generated significantly greater airway and pleural pressures than the anterior thrust technique. We recommend further research to provide additional evidence that may inform management guidelines for clearing foreign body upper airway obstruction.

The use of Angiotensin-I converting enzyme i/d genetic polymorphism as a biomarker of athletic performance in humans.

Angiotensin II is a key regulator of blood pressure and cardiovascular function in mammals. The conversion of angiotensin into its active form is carried out by Angiotensin I-Converting Enzyme (ACE). The measurement of ACE concentration in plasma or serum, its enzymatic activity, and the correlation between an insertion/deletion (I/D) genetic polymorphism of the ACE gene have been investigated as possible indicators of superior athletic performance in humans. In this context, other indicators of superior adaptation to exercise resulting in better athletic performance (such as ventricular hypertrophy, VO2 max, and competition results) were mostly used to study the association between ACE I/D polymorphism and improved performance. Despite the fact that the existing literature presents little consensus, there is sufficient scientific evidence to warrant further investigation on the usage of ACE activity and the I/D ACE gene polymorphism as biomarkers of superior athletic performance in humans of specific ethnicities or in athletes involved in certain sports. In this sense, a biomarker would be a substance or genetic component that could be measured to provide a degree of certainty, or an indication, of the presence of a certain trait or characteristic that would be beneficial to the athlete's performance. Difficulties in interpreting and comparing the results of scientific research on the topic arise from dissimilar protocols and variation in study design. This review aims to investigate the current literature on the use of ACE I/D polymorphism as a biomarker of performance in humans through the comparison of scientific publications.

Determination of angiotensin I-converting enzyme activity in equine blood: lack of agreement between methods of analysis.

Angiotensin-I converting enzyme (ACE) is a key regulator of blood pressure, electrolytes and fluid homeostasis through conversion of angiotensin I into angiotensin II. Recently, a genetic polymorphism of the ACE gene, which accounts for 47% of the variation of ACE activity in blood, has been advocated as a biomarker of athletic aptitude. Different methods of analysis and determination of ACE activity in plasma have been used in human and equine research without a consensus of a "gold standard" method. Different methods have often been used interchangeably or cited as being comparable in the existing literature; however, the actual agreement between assays has not been investigated. Therefore, in this study, we evaluated the level of agreement between three different assays using equine plasma obtained from 29 horses. Two spectrophotometric assays using Furylacryloylphenylalanyl-glycyl-glycine as substrate and one fluorimetric assay utilizing o-aminobenzoic acid-FRK-(Dnp)P-OH were employed. The results revealed that the measurements from the different assays were not in agreement, indicating that the methods should not be used interchangeably for measurement of equine ACE activity. Rather, a single method of analysis should be adopted to achieve comparable results and critical appraisal of the literature is needed when attempting to compare results obtained from different assays.

Stress and immune responses in abalone: limitations in current knowledge and investigative methods based on other models.

Increasing mariculture of abalone focuses attention on their immune and stress responses. For abalone, as well as many invertebrates, the function and relationship of these systems and how in vitro tests relate to them are not fully understood. This review focuses on research into the immune system and stress response conducted on abalone and on aspects that can be monitored in vitro. To fill the considerable knowledge gaps, we discuss work on other invertebrate taxa, concentrating on those closest to abalone, and making explicit the phylogenetic relations involved. The stress response appears to be very similar to that in vertebrates, but interpreting most immune responses remains problematic. Phylogeny must be considered: immune function tests derived from research into vertebrates or distantly related invertebrates should not be used in abalone until they have been validated in abalone by studies of susceptibility to pathogens. We suggest phagocytic activity of haemocytes and their efficiency in clearing bacteria are reliable parameters to measure, because they have been directly related to immune competency and are consistently depressed by stress. Carefully designed assays of antimicrobial activity may also be useful. Important aims of future research will be to investigate the relationship between growth, stress and robust immunity, and to develop tests that can be run on production animals, which accurately depict immune status.

Fluorosis as a probable cause of chronic lameness in free ranging eastern grey kangaroos (Macropus giganteus).

A population of eastern grey kangaroos (Macropus giganteus) inhabiting heathland and farmland surrounding an aluminum smelter at Portland, Victoria, Australia, exhibited clinical signs of lameness. An investigation was undertaken to determine the cause of this lameness. Hematology, necropsy, histopathology, fecal egg count, total worm count, reproductive status, and the population age range were examined and failed to reveal any additional underlying disease state. The specific problem of lameness was addressed with bone histopathology, radiography, quantitative ultrasonography, microradiography, and multielement analysis of bone ash samples. The significant lesions observed were: osteophytosis of the distal tibia and fibula, tarsal bones, metatarsus IV, and proximal coccygeal vertebrae; osteopenia of the femur, tibia, and metatarsus IV; incisor enamel hypoplasia; stained, uneven, and abnormal teeth wear; abnormal bone matrix mineralization and mottling; increased bone density; and elevated bone fluoride levels. Microradiography of affected kangaroos exhibited "black osteons," which are a known manifestation of fluorosis. Collectively, these lesions were consistent with a diagnosis of fluorosis.

Fibrous dysplasia of mandibular bone in a dog.

A nine-year-old, male German shepherd dog was presented with a firm, discrete mass lingual to the interdental space of the mandibular left third and fourth premolars. The lesion was excised and diagnosed as fibrous dysplasia of bone based on histopathologic examination. Fibrous dysplasia of bone is a rare, non-aggressive, radiolucent, non-neoplastic lesion considered developmental in origin. Usually observed as a solitary lesion, it has been reported in animals and man in the polyostotic form. The disease process causes deformity of bone which may lead to loss of bone strength. Clinical signs are secondary to site specific problems associated with expansile bone lesions. Oral examination performed 18-months postoperatively indicated no signs of recurrence.