El malo de tasmania, en serio peligro de extinción.

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Descubren el origen del cáncer que está diezmando a los 'diablos' de Tasmania


Se trata de un cáncer facial que se contagia por contacto físico.
Casi todos los tumores tienen células Schwann.
La enfermedad amenaza con extinguir a esta especie.


.20MINUTOS.ES / EFE. 31.12.2009 - 20.19 hEl cáncer que amenaza con extinguir a los "diablos" de Tasmania se origina en un tipo especial de células y es contagioso por contacto físico, reveló un estudio divulgado este jueves por la revista Science.

El diablo de Tasmania (Sarcophilus harrisii) es un marsupial carnívoro que sólo sobrevive en la isla de Tasmania, al sur de Australia. Tiene el tamaño de un perro pequeño depredador que también se alimenta de carroña.

Debido a que se le consideraba una amenaza para el ganado fue blanco de los cazadores hasta 1941, cuando el gobierno de Tasmania, un estado de Australia, puso fin a su virtual extinción.

Pero ahora su existencia está amenazada por un cáncer facial que ha reducido su población y podría decretar la existencia total del animal en los próximos 40 años, según los científicos.

El cáncer facial que sufren los diablos se origina en las células de Schwann El cáncer se caracteriza por la aparición de grandes tumores en la cara y el hocico del animal, los cuales se propagan después a los órganos internos.

Hasta ahora se sabía que el mal que mata a los diablos es un cáncer, pero los científicos ignoraban su origen.

Sin embargo, investigadores de la Universidad Nacional de Australia determinaron que la enfermedad se origina en las células de Schwann que protegen las fibras nerviosas periféricas.

Según Elizabethg Murchison, que dirigió el estudio, a través de las biopsias, el equipo identificó un marcador genético que podría determinarse para diagnosticar la enfermedad.

"Cuando comparamos las características de los tumores para compararlos con otros tejidos normales descubrimos que casi todos tenían células Schwann", indicó Tony Papenfuss, del Instituto Walter and Eliza Hall, en Melburne (Australia).

Según Greg Woods, del Instituto Menzies de Investigaciones de la Universidad de Tasmania, el descubrimiento es importante por cuanto representa un paso más en los esfuerzos por comprender la enfermedad.

"Los diablos desarrollan tumores de diversos tipos y los marcadores genéticos que hemos identificado nos ayudan a diferenciar los de la enfermedad facial", añadió Woods, que también participó en la investigación


Descubren el origen del cáncer que está diezmando a los 'diablos' de Tasmania - 20minutos.es

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What is Devil Facial Tumour Disease (DFTD) and how does it affect Tasmanian devils?
DFTD describes a horrific and fatal condition in Tasmanian devils which is characterised by the appearance of facial cancers. The tumours or cancers are first noticed in and around the mouth as small lesions or lumps. These develop into large tumours around the face and neck and sometimes even in other parts of the ******

DFTD is extremely unusual as it is only one of three recorded cancers that can spread like a contagious disease. The cancer is passed from devil to devil through biting. The live tumour cells aren’t rejected by their immune system because of a lack of genetic diversity among Tasmanian devils.

DFTD affects mainly adults - males seem to be the first affected, then females - although juveniles as young as one can also be infected. When the disease is advanced Tasmanian devils may have many cancers throughout the ******

Infected devils may become emaciated if the tumours interfere with teeth and feeding. Many females lose their young. Infected animals die within months of the lesions first appearing.


What effect is DFTD having on Tasmanian devil populations?
DFTD was first noticed in 1996 in the north-east of Tasmania. By December 2008 the disease had spread to 64 locations across more than 60% of the State.

There has been a 70% decline in average sightings across Tasmania since the disease emerged. In the north-east region, ’ground zero’, there has been an estimated 95% decline of average spotlighting sightings.

Distribution of DFTD in Tasmania December 2008

The proportion of animals displaying signs of the disease at any one site has reached up to 83% of trapped adults. Such populations are not viable in the long term.

New cases continue to occur in areas where the disease had not previously been recorded as the disease front moves westwards. These sites include Lake Pedder, in the southwest, and the Guildford area, 35km north-west of Cradle Mountain.

At February 2009, populations in the western third of the State appear to have remained healthy and viable.

There is strong concern that, if the devil population continues to diminish while fox numbers increase, it may be difficult for the devils to ever recover.


What is being done about DFTD?
See the Save the Tasmanian Devil website.

The Save the Tasmanian Devil Program,was established in 2003 to investigate the disease and identify management options.

The program is co-ordinated by the Department of Primary Industries, Parks, Water and Environment (DPIPWE) and, involves researchers and experts from a range of institutions, including University of Tasmania, University of Queensland, University of Sydney, Murdoch University, and wildlife parks and zoos.

The Program is focused on the key areas of:
Population monitoring - Gathering data in the field to clarify disease distribution and impacts, and to help determine conservation strategies.
Disease diagnostics - Laboratory-based investigation of the disease itself, which includes defining the disease, exploring its tras*mission, the possible ways to fight it.
Wild management - Establishing methods for managing the impact of the disease in the wild.
Insurance population – An Insurance Population with ‘founders’ taken from areas of the State where there hasn’t been any record of the disease.
The Progam's structure consists of a Steering Committee (involving representatives of DPIPWE, University of Tasmania, Australian Wildlife Health Network and the Australian Government) and a Stakeholder Reference Group (including eco-tourism, farmers, wildlife park operators, RSPCA, Parks and Wildlife Service, veterinary and scientific representatives). Both of these groups are able to provide proper scrutiny to the Program, and also to support and promote its work. For more information see Save the Tasmanian Devil Program.


Population monitoring
Tasmanian devil monitoring sites have been maintained across the State in order to improve our knowledge of the disease. This data helps us to understand the spread of the disease and its impact on wild populations.

Results as at May 2008 indicate that populations remain healthy and viable in the western third of the State. However the disease front is moving westwards and new cases continue to occur in areas where the disease had not previously been recorded.

Monitoring is also continuing at various sites where the disease has been known for long periods. This will provide information on the long-term impacts of the disease and its persistence in populations.

The Save the Tasmanian Devil Program is collaborating with scientists from CSIRO and Landcare Research (in New Zealand), to incorporate this information in predictive models of the devil population and disease changes. To help identify key factors affecting these changes, and will guide the planning of disease control strategies in wild populations.

See what the Save the Tasmanian Devil Program gets up to
View a video (1 minute 29 seconds) showing members of the Save the Tasmanian Devil program staff checking trap sites in the Central Highlands of Tasmania. The specially developed traps are checked on a daily basis and animals are carefully examined by veterinary officers for signs of the disease before being released back into the wild.


Innovations
Wildlife biologist Nick Mooney appeared on ABC TV's New Inventors Program with the PVC poly-trap.
With necessity being the mother of invention, the on-going field work has delivered exciting innovations that help monitor devils.

Remote sensor cameras are being used as a monitoring tool, and are particularly valuable in hard-to-access areas. They are also good to use in low-density devil populations, where the effectiveness of physical trapping is limited.

The new technology, developed by former DPIPWE Scientific Officer Jason Wiersma, consists of a digital camera triggered when an infra-red sensor picks up the movement of an animal. Tasmanian devils are lured into the area by bait placed at the site in an impenetrable container.

Meanwhile the PVC poly-trap, developed by DPIPWE Wildlife Biologist Nick Mooney for catching devils in the wild, gained national praise when Nick appeared on ABC TV’s New Inventors program. His purpose-designed trap, which provides a much less stressful environment for Tasmanian Devils than traditional cages, was voted the People’s Choice Award.


Disease diagnostics
In the laboratory researchers have collected and examined blood, tissue and tumour samples from hundreds of Tasmanian devils to build up a detailed knowledge bank on the disease. The aim is to identify the origin of the cancer cells, as this can give clues to the cause. In collaboration with Murdoch University, the results of their work into the origin of the tumour cells were published in the November 2006 edition of Veterinary Pathology. Their research supports the hypothesis that the tumour cells are of neuroendocrine origin.

In the same edition of Veterinary Pathology, staff from DPIPWE also published a case definition of the disease.

Research by members of the team on the genetic make-up of the tumour cells was published in the international journal Nature. The research indicated that the method of tras*mission of the disease between animals was consistent with direct animal to animal tras*fer.

For the latest research findings and a full list of recent and significant scientific papers visit: Save the Tasmanian devil and the Tasmanian Devil Information Database.


Wild management
Since 2006, scientific officers have been removing diseased Tasmanian devils from the geographically isolated Forestier-Tasman Peninsula in an attempt to contain the impact of DFTD. The Tasman Peninsula was chosen because its physical geography minimises the entry and exit of animals, offering an opportunity to create a disease-free region.

Results, as at December 2009, suggest that this work has not led to the local eradication of the disease.

The project’s effectiveness may have been influenced by the possibility that infected devils are passing on DFTD before they’re being trapped and removed. A diagnostic blood test that confirms DFTD (even before the devil develops tumours) is currently being validated and could be a major breakthrough for disease suppression.

Another factor influencing the effectiveness of the work may be the presence of a ‘cryptic population’ of devils – animals that, for whatever reason, are not being caught and checked in standard traps. The cryptic population, which seems to be around 25%, could be acting as a disease reservoir. The Save the Tasmanian Devil Program is currently looking at alternative trapping patterns and designs to increase the chances of reaching members of the trap-shy cryptic population.



Insurance population
The Save the Tasmanian Devil Program established its Insurance Population in 2005, gathering animals from areas of the State where there had not been evidence of DFTD. As at February 2009, the Insurance Population had grown to 145 disease-free Tasmanian devils.

The animals in the Insurance Population could play an important role, if ever needed, in helping re-establish healthy wild populations in Tasmania.

Tasmanian Devils in the Insurance Population were initially isolated and housed in purpose-built quarantine enclosures before being sent to mainland wildlife institutions approved by the Australasian Regional Association of Zoological Parks and Aquaria (ARAZPA). The decision to remove Tasmanian devils to the mainland of Australia was based on the need to distance from any risk of infection from diseased wild devils.

As at February 2009, parks that are part of the Programs Insurance Population on the Australian Mainland included Adelaide Zoo (SA), Australian Reptile Park (NSW), Ballarat Zoo (VIC), Currumbin Wildlife Sanctuary (QLD), Dreamworld (QLD), Healesville Wildlife Sanctuary (VIC), Monarto Zoological Park (SA), Perth Zoo (WA), Taronga Zoo (NSW) and Western Plains Zoo (NSW).

On advice from ARAZPA, the Save the Tasmanian Devil Program has determined that it needs an effective Insurance Population of around 500 breeding devils to maintain the genetic diversity of the species over a period of 10 to 20 years. This may miccionan having as many as 1,500 devils being intensively managed in captivity – a massive task.

These zoo-based populations are probably sufficient to indefinitely maintain the species, but the Save the Tasmanian Devil Program is also looking at management options that preserve the devils’ natural behaviour.

Free-ranging enclosures (FREs), which don’t require intensive management, are one of the Program's favoured options. There is very little known about managing Tasmanian devils in this way so the Program's experts are working through issues relating to the size of the enclosures, the numbers and ratio of animals that can be housed, den construction, and food sources.


How you can help
Report sightings
Sightings of diseased Tasmanian devils, particularly in areas thought to be disease-free, can be reported to the Save the Tasmanian Devil Hotline: 6233 2006. Messages taken after business hours and at weekends will be responded to the same day (for emergencies), or the next business day (for general sightings).

Reports of sightings should include details on the location, contact details (including a phone number) and the condition of the animal. Members of the public should never touch Tasmanian devils under any circumstances. They are wild animals and they might be diseased, even if you can't see tumours.


Contribute to the Save the Tasmanian Devil Program Appeal
The Save the Tasmanian Devil Program Appeal, launched in late 2003, assists with vital research and management activities in response to DFTD.

You can:
donate online at Save the Tasmanian Devil - University of Tasmania
return a free donation envelope, available from Service Tasmania centres, and Parks and Wildlife Visitor Centres
donate at any Qantas collection sculpture located in domestic airport terminals including Hobart, Launceston, Sydney and Melbourne; the Tasmanian Museum and Art Gallery; Tasmanian Parks and Wildlife Visitor centres at Freycinet, Mt Field, Cradle Mountain and Lake St Clair.
The Appeal is administered under the auspices of the University of Tasmania Foundation, which nominates and allocates a number of scholarships and grants biannually through the Tasmanian Wildlife Research Advisory Committee (TWRAC).

All funds raised by the appeal support key research areas approved by the Devil Facial Tumour Disease Steering Committee. Donations to the Tasmanian Devil Appeal over $2 dollars are tax deductible in Australia.

Visit Save the Tasmanian devil or phone the University of Tasmania Foundation on +61 3 6226 2053 to find out more about the Save the Tasmanian Devil Program Appeal and other ways you can donate to help save the Tasmanian devil.


Volunteer
Do you want to take a more hands-on approach to helping in the fight to save the Tasmanian devil? Do you have a sense of adventure? Then volunteering with the Save the Tasmanian Devil Program field teams may be for you. . More information on volunteering.


Further Information:
Contact: Save the Tasmanian Devil Program
134 Macquarie Street
PO Box 44
HOBART TAS 7001
Phone: 03 6233 2006
Fax: 03 6233 3477
Email: DevilDisease.Enquiries@dpipwe.tas.gov.au

Switchboard: 1300 368 550 (local call cost)


DPIW - Tasmanian Devil Facial Tumour Disease


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El cancer no, pero el bichito que lo provoca si (en el caso de que el cancer en cuestion haya sido provocado por un bichito, claro)

El cancer es el resultado de la multiplicacion sin control de celulas cuyo material genetico ha sufrido una fatal alteracion que las vuelve "inmortales". Dicha alteracion puede producirse por cualquiera de los motivos que producen alteraciones; bichito, radiaciones,...


Oncogenes, agentes mutágenos (tabaco,alquitrán,etileno,asbestos), multiples mitosis por rozaduras continuas (prótesis dentales con holgura,roce de la pipa en los labios, etc). El 99% de los tumores en la lengua, se producen en fumadores.




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