Electrosensory Impairment in the Atlantic Stingray, Hypanus sabinus, After Crude Oil Exposure.

Elasmobranchs are renowned for their extremely sensitive electrosensory system, which is used to detect predators, prey, and mates, and is possibly used for navigation. The proper functioning of the electrosensory system is thus critical to fitness. The objective of this study was to test whether exposure to crude oil impairs the electroreceptive capabilities of elasmobranch fishes. Electrosensory function was quantified from six stingrays before and after exposure to a concentration of oil that mimicked empirically measured concentrations along the coast of Louisiana following the Deepwater Horizon spill. Orientation distance (cm), and angle with respect to the dipole axis of a prey-simulating electric field were used to derive the electric field intensity that elicited a response. Oil exposed stingrays continued to exhibit feeding behavior, but they initiated orientations to prey-simulating electric fields from a significantly closer orientation distance. The mean orientation distance after oil exposure was 5.29 ± 0.41 SE cm compared to a pre-exposure orientation distance of 7.16 ± 0.66 SE cm. Stingrays required a mean electric field intensity of 0.596 ± 0.21 SE µV cm-1 to initiate a response after oil exposure, compared to a mean of only 0.127 ± 0.03 SE µV cm-1 in uncontaminated seawater. Oil exposed stingrays thus exhibited a response to a stimulus approximately 4.7 times greater than controls. Stingrays impacted by an oil spill appear to experience reduced electrosensory capabilities, which could detrimentally impact fitness. This study is the first to quantify the effects of crude oil on behavioral electrosensory function.

Bridging disciplines to advance elasmobranch conservation: applications of physiological ecology.

A strength of physiological ecology is its incorporation of aspects of both species' ecology and physiology; this holistic approach is needed to address current and future anthropogenic stressors affecting elasmobranch fishes that range from overexploitation to the effects of climate change. For example, physiology is one of several key determinants of an organism's ecological niche (along with evolutionary constraints and ecological interactions). The fundamental role of physiology in niche determination led to the development of the field of physiological ecology. This approach considers physiological mechanisms in the context of the environment to understand mechanistic variations that beget ecological trends. Physiological ecology, as an integrative discipline, has recently experienced a resurgence with respect to conservation applications, largely in conjunction with technological advances that extended physiological work from the lab into the natural world. This is of critical importance for species such as elasmobranchs (sharks, skates and rays), which are an especially understudied and threatened group of vertebrates. In 2017, at the American Elasmobranch Society meeting in Austin, Texas, the symposium entitled `Applications of Physiological Ecology in Elasmobranch Research' provided a platform for researchers to showcase work in which ecological questions were examined through a physiological lens. Here, we highlight the research presented at this symposium, which emphasized the strength of linking physiological tools with ecological questions. We also demonstrate the applicability of using physiological ecology research as a method to approach conservation issues, and advocate for a more available framework whereby results are more easily accessible for their implementation into management practices.

Clinical audit and reform of the UK research ethics review system.

There is an international consensus that medical research involving humans should only be undertaken in accordance with ethical principles. Paradoxically though, there is no consensus over the kinds of activities that constitute research and should be subject to review. In the UK and elsewhere, research requiring review is distinguished from clinical audit. Unfortunately the two activities are not always easy to differentiate from one another. Moreover, as the volume of audit increases and becomes more formal in response to the demand for evidence-based practice in medicine, the overlap between research and audit grows more acute. Arguably, similar ethical standards and systems for ensuring that those standards are met should be applied regardless of whether or not a project is classified as research or audit. At a time when the research ethics review system in the UK is undergoing significant reform it is important that the opportunity is not missed to address the longstanding research-audit problem. We discuss suggestions for further reform that addresses this issue.

New governance arrangements for research ethics committees: is facilitating research achieved at the cost of participants' interest.

This paper examines the UK's response to a recent European Clinical Trials Directive, namely the Department of Health, Central Office for Research Ethics Committee guidance, Governance Arrangements for NHS Research Ethics Committees. The revisions have been long awaited by researchers and research ethics committee members alike. They substantially reform the ethical review system in the UK. We examine the new arrangements and argue that though they go a long way toward addressing the uncertainty surrounding ethics committee function, the system favours the facilitation of research over the protection of the dignity and welfare of research participants.

Enteric fistulas and necrotizing enterocolitis.

The incidence, presentation, significance, and outcome of infants with internal enteric fistula formation secondary to necrotizing enterocolitis (NEC) were examined. Of 130 infants with NEC treated during a 7-year period, an enteric fistula developed in five (4%). The gestational age of these patients (3 boys, 2 girls) ranged from 25 to 40 weeks and their birth weight ranged from 800 to 3,460 g. Two had Down's syndrome. Plain abdominal radiographs showed widespread intramural gas in all, and portal vein gas in two. Four patients required early laparotomy, which confirmed extensive intestinal necrosis; a diverting jejunostomy or ileostomy was constructed in three, and the abdomen was closed with drainage in one. Fistulas were diagnosed by contrast radiology between 16 and 51 days after the onset of NEC, and were jejunocolic (2), ileocolic (2), and colocolic (1). They were associated with enteric stricture(s), an inflammatory mass, and clinical signs of intermittent sepsis. One infant with an ileocolic fistula died of sepsis before definitive surgical treatment. Of the four who underwent surgery, two survived after limited intestinal resection, but one of the two with short bowel syndrome died. Enteric fistula formation is a rare complication of NEC. Typically it occurs with colonic stricture(s) and is associated with signs of incomplete bowel obstruction and intermittent sepsis. Resectional surgery is successful, but there appears to be a significant risk of short bowel syndrome.

Carotid artery duplex scanning: does plaque echogenicity correlate with patient symptoms?

In this study we have investigated the relationship between plaque sonolucency and ipsilateral hemispheric symptoms in 116 patients at risk of cerebrovascular disease (75 symptomatic patients, 41 asymptomatic patients). Our results indicate that plaque sonolucency is significantly associated with the incidence of patient symptoms at presentation. Twice as many symptomatic vessels contained the predominantly sonolucent plaque types (types 1 and 2) compared to contralateral asymptomatic vessels (p = 0.039, odds ratio = 2.9). Vessel stenosis also had a significant association with patient symptoms. No significant interaction was shown between vessel stenosis and plaque sonolucency (p = 0.15, odds ratio = 1.0). A model using vessel stenosis and plaque echogenicity as independent variables showed that degree of vessel stenosis had a closer association with incidence of symptoms (p = 0.03, odds ratio = 1.04) than plaque type (p = 0.13, odds ratio = 0.51).

Case report: an unusual case of the superior vena cava syndrome--aneurysm of an aberrant right subclavian artery.

A case of aberrant right subclavian artery (RSA) aneurysm presenting solely with symptoms and signs of superior vena cava obstruction (the SVC syndrome) is described. The SVC syndrome is usually a consequence of mediastinal malignancy and only rarely due to compression by an arterial aneurysm.

Alexander's disease in infancy and childhood: a report of two cases.

Two cases of Alexander's disease are described. One case of infantile onset died at the age of 6 months and the second case was of the juvenile type with onset at 2 years and death at 10 years. A clinical diagnosis of this disease is difficult since signs can vary according to the age of the patient. The severity of the pathological changes can also depend upon the age of onset of this disease, but they are restricted to the central nervous system. The Rosenthal fibre is the characteristic feature of Alexander's disease and we have examined for the first time its ultrastructure and immunocytochemical characteristics at the electron microscopical level and demonstrated coexpression of anti-glial fibrillary acidic protein and anti-ubiquitin antisera.