Stroke: MR or CT, diagnostic accuracy vs logistics
July 23, 2010
The American Academy of Neurology has weighed in heavily on the side of MR as opposed to noncontrast CT for the diagnosis of stroke patients in its newly published practice guidelines. However, the practice may not be feasible in the real world.
According to the president of AHA, it is clear that MR has more diagnostic accuracy than a CT scan for stroke assessment. The latest studies reviewed in the article demonstrate the superiority of MRI for detecting a stroke at an early stadium. However, considering the current situation in most hospitals, it is always faster to do a CT than an MR scan on an acute stroke patient. There are always extra arrangements to be made before the patient can get into the MR scanner and many places do not have more than one MR scanner, which is fully booked the whole day.
As a conclusion, if hospitals are going to implement these guidelines, they probably need to get themselves an MR scanner at the emergency department.
New weapons against cancer?
July 15, 2010
At the UCLA Jonsson Comprehensive Cancer Center, a team of researchers is working on what can be the future in the battle against cancer. Radioactive reporter genes are embedded in lymphocytes, which have been genetically modified to recognize antigens on the surface of melanoma cells. The researchers were able to pack together the cancer specific T-cell receptor and the radioactively labeled reporter genes in a single vector and inject it into the intact immune systems of mice. By using PET imaging, the lymphocytes can be tracked.
By imaging the genetically engineered T cells as they seek out and attack the cancer, the processes of the immune system unfold. In the case of mice, within two to three days after being injected into the bloodstreams of the mice, the cells had found and begun to fight the melanoma. This could take much longer in humans, though.
Monitoring the immune response by PET imaging, could show whether the treatment is working or not, and why not. It also could show how the lymphocytes might be engineered to better fight the tumors.
It is expected that clinical trials in humans could start in one or two years.
For more details, please refer to the article published July 12, Proc Natl Acad Sci U S A, Kinetic phases of distribution and tumor targeting by T cell receptor engineered lymphocytes inducing robust antitumor responses. by Koya RC, Mok S, Comin-Anduix B, Chodon T, Radu CG, Nishimura MI, Witte ON, Ribas A.
Stroke and hypothermia
July 7, 2010
Acute ischemic stroke presents a leading cause of death and disability in the industrialized world. It is characterized by large-vessel thromboembolic occlusion and other pathophysiological factors, which contribute to cellular brain tissue damage.
In the last few years, increasing interest has been focused on regulated hypothermia as a method of
cerebral protection, representing one of the most effective treatment options in reducing further deterioration of brain tissue after acute ischemic stroke, if hypothermia is induced soon after the onset of neurological symptoms and maintained for an adequately long time period.
It is well accepted (based on animal studies) that hypothermia is remarkably neuroprotective when applied during or after global or focal ischemia. Protracted hypothermia of a few ◦C (30-33 C) can provide sustained behavioral and histological neuroprotection, whereas brief or very mild hypothermia (32-35 degrees C) only delays neuronal damage.
However, there are still many questions ananswered, for instance, when and for how long the induced hypothermia should be maintained. Therefore, clinical studies are running to test its efficacy in the
treatment and prevention on stroke in humans.
For more information, consult B. Schaller, R. Graf / Pathophysiology 10 (2003) 7–35
