Loss of biological diversity threatens human health
The rapid loss of biological diversity is a major threat to human health, say researchers in the open access international health journal PLoS Medicine.
Andy Dobson (Princeton University) and colleagues cite the example of Lyme disease, which in eastern North America is transmitted to humans by a blacklegged tick harboring the Lyme bacterium.
The ticks feed on a variety of different vertebrates, including the white-footed mouse and the gray squirrel, each with a different probability of infecting the tick with the Lyme bacterium. Over 90% of ticks feeding on white-footed mice become infected compared with fewer than 15% feeding on gray squirrels, and so ticks harboring the Lyme bacterium are much more common in habitats with many mice than in habitats that harbor a diversity of other species.
These white-footed mice, say the researchers, are more common in small patches of forest. These patches, created by habitat loss and fragmentation of the remaining habitat into smaller subdivided areas, are too small to support the predators and competitors that typically keep mouse numbers down. The loss of species diversity means that the risk to humans of Lyme disease is high in small patches of forest.
Dobson and colleagues give other examples of how loss of biological diversity threatens human health, including West Nile virus, which is transmitted to humans by a range of mosquito species and which can replicate in a variety of bird species. Initial research, say the authors, suggests that cases of human West Nile virus infection are less common in areas with high bird diversity. The virus is particularly likely to replicate in house sparrows, house finches, American robins, blue jays, and grackles, all of which proliferate in heavily fragmented or otherwise degraded habitats.
"Because we are losing biological diversity at the fastest rate ever recorded," say the authors, "we urgently need to understand the dynamics of species interactions, as significant threats to human health may currently be buffered by the presence of a diversity of other species."
Citation: Dobson A, Cattadori I, Holt R, Ostfeld RS, Keesing F, et al. (2006) Sacred cows and sympathetic squirrels: The importance of biological diversity to human health. PLoS Med 3(6): e231.
PLEASE ADD THE LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://dx.doi.org/10.1371/journal.pmed.0030231
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-06-dobson.pdf
Department of Ecology and Evolutionary Biology
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Princeton, NJ 08544-1003 United States of America
A rapid autopsy program for a rare lung disease
Patients with a severe lung disease called interstitial pulmonary fibrosis (IPF) are being offered the chance to donate their lungs for medical research in an innovative new program described in PLoS Medicine.
Kathy Lindell and colleagues, of the Dorothy P. & Richard P. Simmons Center for Interstitial Lung Disease at the University of Pittsburgh, say they established a warm autopsy program (also called a rapid autopsy) after a patient said that he was going to die soon and would like to donate his lungs to research. "I don't want others who get this disease to suffer like me," said the patient.
After a patient with IPF dies, the lungs need to be received within 6 hours if they are to be useful for research, and so setting up the warm autopsy program involved some logistical hurdles.
Warm autopsy programs have been around for over 25 years. Most of the longstanding programs focus on diseases such as Alzheimer's disease and multiple sclerosis, where the organs are relatively inaccessible (they are rarely biopsied from living patients) and therefore samples for research are rare. Lindell and colleagues say that their program is unique because it is the first to specifically focus on lung disease and because it highlights the role of patients in initiating such a program. "Most physicians are hesitant to offer or suggest such programs" said Naftali Kaminski, director of the Simmons Center and senior author. "However, in our case it was a patient initiative and it is pretty much continues to driven by the patients and their families."
Citation: Lindell KO, Erlen JA, Kaminski N (2006) Lessons from our patients: Development of a warm autopsy program. PLoS Med 3(7): e234.
PLEASE ADD THE LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://dx.doi.org/10.1371/journal.pmed.0030234
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-07-kaminski.pdf
University of Pittsburgh School of Medicine
The Dorothy P. and Richard P. Simmons Center for Interstitial Lung Diseases,
University of Pittsburgh Medical Center
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Pittsburgh, PA 15261United States of America
Confronting the global problem of deaths and disability from snake bites
Several million snake bites and envenomings occur world-wide each year, with tens of thousands of deaths, and yet public health authorities have given little attention to this problem, say José María Gutiérrez (University of Costa Rica) and colleagues from the Liverpool School of Tropical Medicine and the University of Oxford.
"Although antivenoms are being produced by various laboratories in every continent, the burden of snake bite envenoming, causing both morbidity and mortality, still has a great impact on the population and on healthcare systems, especially in Africa, Asia, Oceania and Latin America," they say. The authors consider that snake bite envenoming is "a major neglected disease of the 21st century."
In parts of the world there is a continuing crisis in the production, deployment and accessibility of antivenoms, they say, and international collaboration is needed to produce effective and safe antivenoms in the regions where they are not available. The authors argue that the World Health Organization would be best placed to play a coordinating role in such a collaboration, which should involve national and regional health organisations and diverse public-private partnerships.
Citation: Gutiérrez JM, Theakston RDG, Warrell DA (2006) Confronting the neglected problem of snake bite envenoming: The need for a global partnership. PLoS Med 3(6): e150.
PLEASE ADD THE LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://dx.doi.org/10.1371/journal.pmed.0030150
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-06-gutierrez.pdf
José María Gutiérrez
Instituto Clodomiro Picado
Facultad de Microbiología
Universidad de Costa Rica
San José, Costa Rica.
Do psychiatric drugs help symptoms by inducing abnormal brain states?
Antidepressants and other psychotropic drugs may have their effect by creating abnormal brain states that coincidentally relieve psychiatric symptoms in the short term, say two researchers in a provocative essay in PLoS Medicine.
Dr Joanna Moncrieff (University College London) and Professor David Cohen (Florida International University) argue that psychotropic drugs create abnormal states with a wide range of effects, including sedation, indifference, or stimulation. These effects could in turn relieve symptoms of mental illness.
For example, antipsychotic drugs, they say, induce indifference and sedation, which could in the short term help to relieve the symptoms of acute psychosis (such as hearing voices, which is very disturbing to patients). Similarly, the sedative effects of many psychiatric drugs could in the short term, they say, help patients who are anxious or having difficulty sleeping.
However, Moncrieff and Cohen do not believe that any drugs, including the class of drugs called antidepressants, can counteract depression. They suggest that the utility of known drug effects in depression is very limited. They claim that there is little evidence that psychiatric drugs work in the long term by actually correcting any underlying disease process in the brain, if such a process actually exists (in the way that insulin corrects diabetes).
Citation: Moncrieff J, Cohen D (2006) Do antidepressants cure or create abnormal brain states? PLoS Med 3(7): e240.
PLEASE ADD THE LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://dx.doi.org/10.1371/journal.pmed.0030240
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-07-moncrieff.pdf
University College London
Mental Health Services
Riding House Street
London, W1A 8NN United Kingdom
+44 1277 302695
+44 1277 302696 (fax)
Florida International University
School of Social Work
Miami, FL 33199 United States of America
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