Exposure to toxins reduces the effectiveness of immunisation and more
Researchers have found that when children have been accidentally exposed to a group of chemicals widely used in industry (polychlorinated biphenyls or PCBs) vaccination against infections provides them with less protection than is the case for unexposed children.
The research was carried out in the Faroe Islands in the North Atlantic, where people have often been exposed to high levels of PCBs through eating contaminated whale blubber. The children in the study received standard, routine vaccinations against diphtheria and tetanus. The researchers measured both the level of PCBs in the children's bodies and the level of protective antibodies against the two diseases produced in response to the vaccinations. They found that the higher the level of PCB exposure, the lower the level of antibody protection. The study shows that every effort must be made to reduce the exposure of young children to chemicals that could harm their immune systems.
All works published in PLoS Medicine are open access. Everything is immediately available without cost to anyone, anywhere -- to read, download, redistribute, include in databases, and otherwise use -- subject only to the condition that the original authorship is properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.
Citation: Heilmann C, Grandjean P, Weihe P, Nielsen F, Budtz-Jørgensen E (2006) Reduced antibody responses to vaccinations in children exposed to polychlorinated biphenyls. PLoS Med 3(8): e311.http://dx.doi.org/10.1371/journal.pmed.0030311
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-08-grandjean.pdf
Smallpox vaccination risks -- lessons from the past
Smallpox vaccination has some adverse effects, including post-vaccination encephalitis which can cause permanent brain damage and has been estimated to kill one vaccinee in every million. Consequently, as smallpox became rarer, the dangers of vaccination began to outweigh its benefits, and routine vaccination was stopped.
Now, however, there are fears that smallpox may be used for bioterrorism. If this did happen, exposed individuals and their contacts, possibly even whole populations, would have to be vaccinated as quickly as possible. Many countries have stockpiles of smallpox vaccines for this eventuality, but these contain different vaccinia virus strains. Miriam Kretzschmar and colleagues have analysed historical data and argue that the different stockpiled strains differ quite substantially in their potential to cause encephalitis. This information should help public-health officials plan their vaccination strategies in response to a bioterrorism attack with smallpox.
Citation: Kretzschmar M, Wallinga J, Teunis P, Xing S, Mikolajczyk R (2006) Frequency of adverse events after vaccination with different vaccinia strains. PLoS Med 3(8): e272.
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-08-kretzschmar.pdf
University of Bielefeld
School of Public Health
PO Box 100131
Bielefeld, 33501 Germany
Are schools prepared to deal with serious allergies of pupils?
Severe allergies are on the rise, but a survey of schools in Scotland suggests that many of them are ill-prepared to protect their pupils, as reported by Aziz Sheikh and colleagues in the international open-access medical journal PLoS Medicine.
Foods are the most common trigger of anaphylaxis, a severe and potentially life threatening allergic reaction, in children. Anaphylaxis can develop both in people known to have a tendency (risk) of getting the condition, or in those with no known risk. Sheikh and colleagues mailed questionnaires to 250 Scottish schools, of which 148 replied. 90 of them reported having at least one child with a known risk of developing anaphylaxis. Of those, most had at least one staff member trained to treat anaphylaxis, and almost all had the drug adrenaline (epinephrine) on site, which is a life-saving medication for treating anaphylaxis. However, many of the schools were doing poorly at reducing the risk of anaphylaxis -- for example, only 1 in 3 of these schools banned the sharing of eating utensils. Another worrying finding was that among the 58 schools that did not have children known to be at risk of anaphylaxis, less than half had a trained member of staff and only about 1 in 8 of these schools had adrenaline on site.
The study suggests that there needs to be detailed guidance for all schools in Scotland on preventing and treating anaphylaxis.
Citation: Rankin KE, Sheikh A (2006) Serious shortcomings in the management of children with anaphylaxis in Scottish schools. PLoS Med 3(8): e326.
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-08-sheikh.pdf
Division of Community Health Sciences
General Practice Section
20 West Richmond St
Edinburgh, EH8 9DX United Kingdom
Potential biomarkers for schizophrenia
Schizophrenia is a disease for which no "objective" biological test exists. The current diagnosis is based on the symptoms experienced and reported by the patient, in combination with signs observed by a psychiatrist, clinical psychologist, or other clinician. Results by Sabine Bahn and colleagues reported in the international open-access medical journal PLoS Medicine suggest that studying "metabolic profiles" of patients might yield a set of biomarkers that could reliably help in early diagnosis of schizophrenia. Such biomarkers might possibly also help in monitoring patients' responses to drug treatment.
In their search for biomarkers, Bahn and colleagues examined the levels of different molecules present in the cerebrospinal fluid of 82 patients with schizophrenia and 70 healthy controls. Of the patients, 54 had just been diagnosed with schizophrenia (or a similar illness called brief psychotic disorder) and had not yet taken any schizophrenia-specific drugs. The remaining patients were undergoing treatment with a range of antipsychotic drugs. The researchers found different levels of certain molecules in the spinal fluid of newly diagnosed patients who had never taken schizophrenia drugs compared with healthy individuals of the same ages. These molecules might therefore turn out to be useful biomarkers for schizophrenia. The differences between patients and controls suggested that the metabolism of several substances--including glucose and acetate--might be altered in the brains of patients with schizophrenia or brief psychotic disorder. The researchers also found that the levels of these molecules in some of the patients with newly diagnosed schizophrenia who were given medication became similar to the levels in the control individuals.
These are promising early results which need to be tested in larger studies to determine their clinical relevance.
Citation: Holmes E, Tsang TM, Huang JTJ, Leweke FM, Koethe D, et al. (2006) Metabolic profiling of CSF: Evidence that early intervention may impact on disease progression and outcome in schizophrenia. PLoS Med 3(8): e327.
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-08-bahn.pdf
University of Cambridge
Cambridge Centre for Neuropsychiatric Research
Tennis Court Road
Cambridge, CB2 1QT
New method for assessing environmental risk for leptospirosis
Concentrations of virulent Leptospira -- which can cause leptospirosis in humans -- are higher in urban than in rural environmental surface waters in a region of Peru.
A study published in the international open-access medical journal PLoS Medicine describes a technique (quantitative real time PCR assay combined with molecular taxonomic analysis) which was used to measure Leptospira in environmental surface waters in the Peruvian Amazon region of Iquitos. Joseph Vinetz and colleagues from University of California San Diego School of Medicine, Johns Hopkins Bloomberg School of Public Health, and Instituto de Medicina Tropical Alexander von Humboldt, Peru, suggest that the new technique could be widely used to assess risk for leptospiral infection and severe disease in leptospirosis-endemic regions.
Leptospirosis occurs in temperate and tropical climates, and in urban and rural settings. It is the most widespread zoonotic disease (disease acquired from animals), and is caused by Leptospira, a large group of closely related spiral-shaped bacteria that live in both domestic and wild animals. Millions of humans become infected each year with leptospires through close contact with water, food, or soil contaminated with the urine of infected animals -- swimming or wading in contaminated water is particularly hazardous.
This new information should aid attempts to control leptospirosis. The authors suggest for example that environmental interventions such as reducing sources of standing water and clearing away garbage in urban areas might reduce the number of cases of severe leptospirosis.
Citation: Ganoza CA, Matthias MA, Collins-Richards D, Brouwer KC, Cunningham CB, et al. (2006) Determining risk for severe leptospirosis by molecular analysis of environmental surface waters for pathogenic Leptospira. PLoS Med 3(8): e308.
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-08-vinetz.pdf
University of California San Diego
School of Medicine/Division of Infectious Diseases
9500 Gilman Drive, 0741
George Palade Laboratories,
Cellular and Molecular Medicine-West, Room 125
La Jolla, California 92093-0741 United States of America
Inflammation and risk of venous thrombosis
The results from a large population-based study in Norway, published in the international open-access medical journal PLoS Medicine, show that altered levels of inflammatory markers are more likely to be a result rather than a cause of venous thrombosis, although short-term effects of transiently elevated levels cannot be ruled out.
Citation: Christiansen SC, Næss IA, Cannegieter SC, Hammerstrøm J, Rosendaal FR, et al. (2006) Inflammatory cytokines as risk factors for a first venous thrombosis: A prospective population-based study. PLoS Med 3(8): e334.
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-08-reitsma.pdf
Academic Medical Center
Laboratory for Experimental Internal Medicine
Amsterdam, NH 1105 AZ Netherlands
Reconstructing tuberculosis services after major conflict: experiences and lessons learned in East Timor
A qualitative study of re-introduction of tuberculosis services in East Timor in 1999 after a period of civil conflict, published in the international open-access medical journal PLoS Medicine, concludes that coordination, cooperation, and collaboration contributed to the success of the services.
Citation: Martins N, Kelly PM, Grace JA, Zwi AB (2006) Reconstructing tuberculosis services after major conflict: Experiences and lessons learned in East Timor. PLoS Med 3(10): e383.
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-10-kelly.pdf
The Australian National University,
College of Medicine & Health Sciences
National Centre for Epidemiology and Population Health
Canberra, ACT 0200 Australia
Too little research on treating life-threatening sepsis
Severe infections, which can be fatal, are common in patients in intensive care and yet there has been little high quality research on how best to treat these infections, says a leading intensive care specialist.
Around 3 in 10 patients in intensive care units develop severe sepsis, and of these around 3 in 10 will die from the infection. Professor Jean-Louis Vincent (Department of Intensive Care, Erasme Hospital, Free University of Brussels) says that "it is difficult to provide guidelines for the management of the patient with sepsis," since too few high quality clinical trials have been performed.
For example, he says, while patients with severe sepsis sometimes suffer from dangerously low blood pressure (septic shock) and need drugs to raise their blood pressure, there have been few trials on which drugs work best.
"The results of ongoing and future trials will expand the evidence base," says Professor Vincent, "and current guidelines need to be adapted accordingly to ensure that patients continue to be treated with the very latest and best standard of care."
Citation: Vincent JL (2006) Is the current management of severe sepsis and septic shock really evidence-based? PLoS Med 3(9): e346.
PRESS-ONLY PREVIEW OF THE ARTICLE: http://www.plos.org/press/plme-03-09-vincent.pdf
Erasme University Hospital
Route de Lennik 808
Brussels, 1070 Belgium
About PLoS Medicine
PLoS Medicine is an open access, freely available international medical journal. It publishes original research that enhances our understanding of human health and disease, together with commentary and analysis of important global health issues. For more information, visit http://www.plosmedicine.org
About the Public Library of Science
The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org
Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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