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Articles
New Recommendations For The Diagnosis Of Pulmonary Embolism
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Diagnosis
of Pulmonary Embolism (PE) is a challenging process. Because PE is
only present in about one-third of those in whom it is suspected,
the diagnosis must be confirmed or excluded by further testing. In
an article in the December issue of The American Journal of
Medicine, researchers describe the diagnostic pathways that can
be used to achieve an accurate and safe diagnosis of PE.
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Based on the results from the Prospective Investigation of Pulmonary
Embolism Diagnosis II (PIOPED II) and other studies, these
guidelines include both evidence-based recommendations and opinions
based on information available at this time.
Writing in the article, Paul D. Stein, MD, states "[we] recommend
stratification of all patients with suspected pulmonary embolism
according to an objective probability assessment. A negative D-dimer
rapid ELISA with a low or moderate probability clinical assessment
can safely exclude pulmonary embolism. If pulmonary embolism is not
excluded, CT angiography/CT venography is recommended by most PIOPED
II investigators, although CT angiography alone is an option. In
patients with discordant findings on clinical assessment and CT
imaging, further evaluation depends on clinical judgment. In
pregnant women and women of reproductive age, ventilation/perfusion
scans are recommended by many PIOPED II investigators as the first
imaging test."
In an accompanying commentary, James E. Dalen, MD, MPH, describes
how various techniques for the diagnosis of PE have been introduced
over the last 40 years, each with advantages and disadvantages in
accuracy, risk to the patient and cost. Writing about the article,
he states, "These recommendations from the PIOPED investigators will
have a major impact on the diagnosis and treatment of pulmonary
embolism."
The study is "Diagnostic Pathways in Acute Pulmonary Embolism:
Recommendations of The PIOPED II Investigators" by Paul D. Stein,
MD, Pamela K. Woodard, MD, John G. Weg, MD, Thomas W. Wakefield, MD,
Victor F. Tapson, MD, H. Dirk Sostman, MD, Thomas A. Sos, MD,
Deborah A. Quinn, MD, Kenneth V. Leeper, Jr, MD, Russell D. Hull,
MBBS, MSc, Charles A. Hales, MD, Alexander Gottschalk, MD, Lawrence
R. Goodman, MD, Sarah E. Fowler, PhD, and John D. Buckley, MD, MPH.
The commentary is "Prospective Investigation of Pulmonary Embolism
Diagnosis (PIOPED I, II, and III) and the Diagnosis of Pulmonary
Embolism" by James E. Dalen, MD, MPH. These appear in The
American Journal of Medicine, Volume 119, Issue 12 (December
2006), published by Elsevier.
Contact: Pamela Poppalardo
Protein Protects Against Nerve Degeneration
A protein called NMNAT protects against nerve cell degeneration in
fruit flies and mice, said Baylor College of Medicine researchers in
a report in the Public Library of Science Biology that
appears online.
The finding begs the question if a drug might be developed that
could stimulate extra protein production and thus neuronal
protection - both in injured cells and in those degenerating because
of disease, said Dr. Hugo Bellen, the paper's senior author,
director of the BCM Program in Developmental Biology and a Howard
Hughes Medical Institute investigator. While more work needs to be
done to determine whether that would be desirable, Bellen said the
finding is an important one because it identifies NMNAT as essential
in the life of the body's neurons.
Much of the work described in the paper was done by its first
author, Dr. R. Grace Zhai, a postdoctoral fellow in Bellen's
laboratory.
The story began two decades ago when researchers in the U.K.
discovered a mouse whose injured nerve cells were slow to die. Even
when the nerve was cut, it had some function two weeks later while
in a normal mouse injured nerves are non-functional within two days,
said Bellen.
Five years ago, researchers discovered that the mice had three
copies of a gene for a protein that was a fusion of NMNAT and
another protein. Bellen and his colleagues sought to determine
whether NMNAT was actually protective by studying mutant forms of it
in fruit flies or Drosophila melanogaster, a commonly used model
organism. NMNAT exists in a single state in the fruit fly, and there
is only one form of it.
When Zhai, Bellen and colleagues bred flies that lack the protein in
their visual system, they found that the neurons degenerated very
rapidly. However, the degeneration could be slowed by keeping the
flies in the dark and preventing their visual neurons from
activating.
"In the absence of the NMNAT protein, the photoreceptors in the eye
develop normally. They send out axons (tendril extension of the
nerve that grow into the brain) and make synapses (the functional
connection between a nerve axon and the target cell)," said Bellen.
However, late in the development of the eye, the insects in the
pupal stage begin to sense light. As the neurons become active, they
degenerate rapidly. Within two weeks after birth, there are almost
no neurons left.
"Here is a case where the protein is required for the maintenance of
the neuron," said Bellen.
When flies were raised in the dark, the neurons died, but at very
slow pace when compared to those exposed to light.
"Activity clearly causes a massive degeneration," he said.
When they exposed flies that made large quantities of NMNAT in the
eye to bright sunlight for 30 days, they found that only 20 percent
of the neurons died - not the 80 percent that would have been
expected.
"This protein can delay the neuronal degeneration process if it is
present at a high level," said Bellen.
They also found that NMNAT alone and not the enzyme partner found in
mice and other vertebrates was sufficient to protect the neurons.
Bellen said more work needs to be done to identify the mechanisms at
work in the neuronal protection and to determine how to prompt cells
to increase productions of the protein.
Others who participated in the research include Drs. Yu Cao, P.
Robin Hiesinger, Yi Zhou, Sunil Q. Mehta, Karen L. Schulze and
Patrik Verstreken, all of BCM.
Support for this study came from the Howard Hughes Medical
Institute.
Contact: Ross Tomlin
Baylor College of Medicine
Nutrition Is An Essential Part Of Basic Patient Care, Says BMA Scotland
The BMA in Scotland has welcomed the publication of an Audit
Scotland report into catering for patients in hospital which found
that progress had been made on recommendations made in an initial
review in 2003.
The report however identified a need for routine screening for
under-nutrition of patients on admission to hospital and for all NHS
Boards to have systems for ensuring the nutritional balance of
patient meals.
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The BMA's lead on nutritional issues, Dr Sumantra Ray, said:
"Since 2003 it has been mandatory, under NHS quality standards, for
patients to be screened for risk of under-nutrition on admission to
hospital, but the Audit Scotland report has clearly identified that
there are still barriers to the implementation of these standards in
our hospitals.
"Ensuring patients receive adequate nutrition is an essential part
of basic patient care as well as a basic human right as highlighted
by the Council of Europe. Despite this, hospital malnutrition
remains a major problem in the NHS and this must be addressed as a
matter of urgency. It is estimated that UK-wide, malnutrition costs
the NHS £7.3 billion a year.
"It is ironic that, at a time when the importance of eating well is
high on the health agenda, that this is not mirrored in our
hospitals."
Dr Ray, who is both a fully trained Registered Nutritionist and
Registered Medical Doctor working as a Clinical Research and
Teaching Fellow at the University of Dundee, added:
"Based on extrapolated data, at least 40% of patients admitted to
hospitals in this country are undernourished, 10% higher than the EU
average. Under-nutrition can contribute to prolonged ill health,
clinical complications, delayed recovery and therefore longer
hospital stays.
"There is an urgent need for multi-professional nutrition education
to improve hospital food in general and to manage the burden of
hospital malnutrition. The BMA is currently leading a tentative
project (within the framework of the Council of Europe Alliance (UK)
on Hospital Food and Nutritional Care) to assess the need for
nutritional education in UK medical schools and to inform curriculum
planners of the need for nutrition related skills required by all
doctors.
"There is also a need to make special meals more widely available by
hospital caterers to take account of specific dietary requirements,
especially for vegetarians or the 6-7% of British people who are
registered gluten sensitive."
In its recently published election manifesto, Priorities for Health¸
the BMA in Scotland called for mandatory standards for all meals
provided by the public sector, including hospital meals.
The Audit Scotland report Caring for Patients: a follow up report is
available online at:
http://www.audit-scotland.gov.uk
The BMA Scotland Manifesto Priorities for Health is available online
at
http://www.bma.org.uk/scottishelections
For further information please go to:
BMA Scotland
Source:
BMA News, the membership magazine of the British
Medical Association
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