Advances in research on the impacts of anti-submarine sonar on beaked whales.

Mass stranding events (MSEs) of beaked whales (BWs) were extremely rare prior to the 1960s but increased markedly after the development of naval mid-frequency active sonar (MFAS). The temporal and spatial associations between atypical BW MSEs and naval exercises were first observed in the Canary Islands, Spain, in the mid-1980s. Further research on BWs stranded in association with naval exercises demonstrated pathological findings consistent with decompression sickness (DCS). A 2004 ban on MFASs around the Canary Islands successfully prevented additional BW MSEs in the region, but atypical MSEs have continued in other places of the world, especially in the Mediterranean Sea, with examined individuals showing DCS. A workshop held in Fuerteventura, Canary Islands, in September 2017 reviewed current knowledge on BW atypical MSEs associated with MFAS. Our review suggests that the effects of MFAS on BWs vary among individuals or populations, and predisposing factors may contribute to individual outcomes. Spatial management specific to BW habitat, such as the MFAS ban in the Canary Islands, has proven to be an effective mitigation tool and mitigation measures should be established in other areas taking into consideration known population-level information.

Retrospective study of foreign body-associated pathology in stranded cetaceans, Canary Islands (2000-2015).

Marine pollution, overrepresented by plastic, is a growing concern worldwide. However, there is little knowledge on occurrence and detrimental impacts of marine debris in cetaceans. To partially fill in this gap of knowledge, we aimed to investigate the occurrence and pathologies associated with foreign bodies (FBs) in a large cohort of cetaceans (n = 465) stranded in the Canary Islands. The Canary Islands shelter the greatest cetacean biodiversity in Europe, with up to 30 different species, of which nine are regularly present year around. We found at least one ingested FB in 36 out of 465 (7.74%) studied cetaceans, involving 15 different species, including eight out of the nine (80%) cetacean species present year-round in the Canary Islands. Risso's dolphin was the species most affected, followed by sperm whale, beaked whale and mysticetes. Plastic FB were the most common item found (80.56%). FB was directly associated with death in 13/36 (36.11%) animals. Poor body condition and deep diving behavior were found to be risk factors for FB ingestion, whereas the adult age was a protective factor. To the authors knowledge this is the first study that use statistical analysis to investigate risk and protective factors for FB ingestion. This study also provides insights of the potential impact caused by ingested FBs on the animal's health and mortality. This knowledge is critical to better understand and assess the impact of FB in cetaceans setting the scientific basis for prospective impact monitoring and future conservation policies.

Deadly acute Decompression Sickness in Risso's dolphins.

Diving air-breathing vertebrates have long been considered protected against decompression sickness (DCS) through anatomical, physiological, and behavioural adaptations. However, an acute systemic gas and fat embolic syndrome similar to DCS in human divers was described in beaked whales that stranded in temporal and spatial association with military exercises involving high-powered sonar. More recently, DCS has been diagnosed in bycaught sea turtles. Both cases were linked to human activities. Two Risso's dolphin (Grampus griseus) out of 493 necropsied cetaceans stranded in the Canary Islands in a 16-year period (2000-2015), had a severe acute decompression sickness supported by pathological findings and gas analysis. Deadly systemic, inflammatory, infectious, or neoplastic diseases, ship collision, military sonar, fisheries interaction or other type of lethal inducing associated trauma were ruled out. Struggling with a squid during hunting is discussed as the most likely cause of DCS.

Verminous Arteritis Due to Crassicauda sp. in Cuvier's Beaked Whales (Ziphius Cavirostris).

The vascular system of Cuvier's beaked whales (CBW) (Ziphius cavirostris; family Ziphiidae), an extremely deep, prolonged-diving cetacean, is increasingly receiving anatomic and physiologic study due to possible anthropogenic interactions; however, vascular pathology rarely has been reported in this species. Thirteen CBW stranded in the Canary Islands from June 2008 to June 2014 were autopsied. A careful dissection of the thoracic and abdominal vasculature was performed on these animals. All had moderate to severe and extensive chronic fibrosing arteritis with aneurysms, hemorrhages, and thrombosis primarily involving the mesenteric and gastroepiploic arteries and the thoracic and abdominal aorta. Microscopically, the lesions varied from subacute subintimal hemorrhages and severe neutrophilic, eosinophilic, and histiocytic dissecting arteritis with intralesional nematode larvae to marked, chronic, fibrosing arteritis with thickening and distortion of the vascular wall with calcification and occasional cartilage metaplasia. In addition, adult nematodes in renal arteries and veins, renal parenchyma and/or ureter were identified morphologically as Crassicauda sp. Nucleic acid sequenced from renal nematodes from 2 animals yielded closest nucleotide identity to C. magna The pathogenesis is proposed to involve a host response to larval migration from the intestine to the kidney through the mesenteric arteries, abdominal aorta, and renal arteries. Severe consequences for such lesions are possible and could vary from reduced vascular compliance to chronic renal disease and predisposition to the development of disseminated intravascular coagulation and multiorgan failure. Severe chronic arteritis in CBW is associated with renal parasitism by Crassicauda spp.

Comparative histology of muscle in free ranging cetaceans: shallow versus deep diving species.

Different marine mammal species exhibit a wide range of diving behaviour based on their breath-hold diving capabilities. They are classically categorized as long duration, deep-diving and short duration, shallow-diving species. These abilities are likely to be related to the muscle characteristics of each species. Despite the increasing number of publications on muscle profile in different cetacean species, very little information is currently available concerning the characteristics of other muscle components in these species. In this study, we examined skeletal muscle fiber type, fiber size (cross sectional area and lesser diameter), intramuscular substrates, and perimysium-related structures, by retrospective study in 146 stranded cetaceans involving 15 different species. Additionally, we investigated diving profile-specific histological features. Our results suggest that deep diving species have higher amount of intramyocyte lipid droplets, and evidence higher percentage of intramuscular adipose tissue, and larger fibre sizes in this group of animals.

Decompression sickness ('the bends') in sea turtles.

Decompression sickness (DCS), as clinically diagnosed by reversal of symptoms with recompression, has never been reported in aquatic breath-hold diving vertebrates despite the occurrence of tissue gas tensions sufficient for bubble formation and injury in terrestrial animals. Similarly to diving mammals, sea turtles manage gas exchange and decompression through anatomical, physiological, and behavioral adaptations. In the former group, DCS-like lesions have been observed on necropsies following behavioral disturbance such as high-powered acoustic sources (e.g. active sonar) and in bycaught animals. In sea turtles, in spite of abundant literature on diving physiology and bycatch interference, this is the first report of DCS-like symptoms and lesions. We diagnosed a clinico-pathological condition consistent with DCS in 29 gas-embolized loggerhead sea turtles Caretta caretta from a sample of 67. Fifty-nine were recovered alive and 8 had recently died following bycatch in trawls and gillnets of local fisheries from the east coast of Spain. Gas embolization and distribution in vital organs were evaluated through conventional radiography, computed tomography, and ultrasound. Additionally, positive response following repressurization was clinically observed in 2 live affected turtles. Gas embolism was also observed postmortem in carcasses and tissues as described in cetaceans and human divers. Compositional gas analysis of intravascular bubbles was consistent with DCS. Definitive diagnosis of DCS in sea turtles opens a new era for research in sea turtle diving physiology, conservation, and bycatch impact mitigation, as well as for comparative studies in other air-breathing marine vertebrates and human divers.

Deadly diving? Physiological and behavioural management of decompression stress in diving mammals.

Decompression sickness (DCS; 'the bends') is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N(2)) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N(2) tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N(2) loading to management of the N(2) load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years.

La exposición crónica al uranio, un riesgo potencial de nefrotoxicidad / Uranium is a naturally occurring element widely distributed in the crust

El uranio es un elemento natural que se encuentra ampliamente distribuido en la corteza terrestre. Cierta cantidad de este metal se encuentra presente en los alimentos, en el aire, en el suelo y en el agua, por lo que el ser humano se encuentra expuesto al mismo de forma natural. Pero también puede ser objeto de una sobreexposición patológica como consecuencia de la deposición de uranio natural desde la atmósfera o debido a actividades industriales humanas que vierten productos de desecho directamente sobre el terreno. Actualmente la exposición debida a la actividad industrial se ha incrementado debido a que el uranio representa una de las pocas fuentes energéticas que cumplen con el “Protocolo de Kyoto”, sumándole la ventaja de que es muy económico. España, es uno de los países Europeos con más contenido de uranio en su suelo y por ello, susceptible de exposición natural, pero también industrial, ya que dada la demanda energética se están reabriendo algunas de sus minas. La nefrotoxicidad es el principal efecto observado tras exposición aguda a uranio. Este efecto se ha descrito en múltiples estudios realizados en animales de experimentación y en algunos casos de humanos expuestos a dosis elevadas de uranio de forma accidental. Sin embargo, la producción de daño renal por exposición crónica está poco documentada. Existen escasos estudios experimentales en los que se administren bajas dosis de uranio durante largos periodos de tiempo y los referidos en humanos son muy heterogéneos en cuanto a la vía de exposición, la dosis, el tipo de uranio etc, por lo que resulta muy difícil extraer conclusiones sobre los efectos renales por sobreexposición crónica. En esta revisión se pretende hacer una recopilación y discusión de gran parte de estudios epidemiológicos y de experimentación, a fin de obtener una idea de la nefrotoxicidad real que supone la exposición crónica a este metal para el ser humano (AU)

Certain amount of this metal is present in food, air, soil and water, for that humans are exposed to it naturally. But it can also be pathological overexposure as a result of natural uranium deposition from the atmosphere or due to human industrial activities that discharge waste products directly on the ground. Currently exposure due to industrial activity has increased because the uranium is one of the few sources of energy that meet the "Kyoto Protocol", adding the advantage that it is very economical. Spain is one of most European countries with uranium content in soil and thus susceptible to natural exposure, but also industrial, as given energy demand are reopening some of its mines. Nephrotoxicity is the main effect observed after acute exposure to uranium. This effect has been described in multiple studies in experimental animals and in some cases of humans accidentally exposed to high doses of uranium. However, the production of kidney damage from chronic exposure is poorly documented. There are few experimental studies in which low doses are administered uranium for long periods of time. Moreover, data in humans are very heterogeneous regarding the route of exposure, dose, type of uranium etc, so it is very difficult to draw findings on chronic renal effects of overexposure. In this review we tried to make a compilation and discussion of several epidemiological and experimental studies in order to get an idea of the real nephrotoxicity involving chronic exposure to this metal to humans (AU)

Weissella ceti sp. nov., isolated from beaked whales (Mesoplodon bidens).

During an investigation into the microbiota of beaked whales (Mesoplodon bidens), nine isolates were obtained from different organs of four animals. The isolates were Gram-positive-staining, catalase-negative, short rod-shaped or coccoid organisms. A phylogenetic analysis based on 16S rRNA gene sequences of these isolates allocated them to the genus Weissella, showing 96.3 % and 96.0 % 16S rRNA gene sequence similarity with Weissella viridescens NRIC 1536(T)and Weissella minor NRIC 1625(T), respectively. On the basis of phenotypic, physiological and phylogenetic evidence, it is proposed that the new isolates from whales represent a novel species of the genus Weissella, Weissella ceti sp. nov. The type strain of Weissella ceti is 1119-1A-09(T) ( = CECT 7719(T) = CCUG 59653(T)).

Sedación y analgesia en cirugía bucal / Sedation and analgesia for oral surgery

La sedación consciente es una técnica anestésica cada día más habitual en la práctica odontológica. La demanda de sedación y analgesia está aumentando, de forma que se estima que el 85 por ciento de los pacientes de cirugía oral prefiere la anestesia local con sedación mejor que anestesia local exclusivamente. Puede controlar el comportamiento de pacientes no colaboradores en procesos no muy dolorosos pero que requieren inmovilidad. Además, numerosas técnicas habitualmente realizadas bajo anestesia general pueden ser realizadas bajo sedación consciente con menor gasto y menor riesgo para el paciente. El objetivo de este artículo es describir la monitorización y equipo necesarios así como las técnicas enterales, inhalatorias y parenterales más habituales (AU)