A recent paper from Miller and psychiatry chair Mark Rapaport looks at clinical trials testing an anti-inflammatory drug against psoriasis, to see whether participants’ depressive symptoms improved. Read more
Space considerations in printÂ forced usÂ to slim down the feature on deep brain stimulation for drug resistant epilepsy, which appears in the Spring 2015 issue of Emory Medicine.Â While I encourage you to please read ourÂ story profilingÂ playwright Paula Moreland, here are some take-away points:
*Surgery is a viable option for many patients with drug-resistant epilepsy, but not all of them, because the regions of the brain where the seizures start canÂ have important functions. (Look for an upcoming post describing a patient I met for whom theÂ surgical option was helpful.)
*Deep brain stimulation can reduce seizure frequency and improve quality of life for patients with drug-resistant epilepsy.
*In the large clinical trials on deep brain stimulation for epilepsy that have been run so far (SANTE and RNS), most participants do not see their seizures eliminated. Ms. Moreland is an exception.Â Read more
To go along with the (new) Spring 2015Â Emory Medicine magazine set of features on deep brain stimulation for depression, movement disordersÂ and epilepsy, here is a fascinating 2013 case report from Emory neurosurgeon Robert Gross and colleagues. The first author is electrical engineer Otis Smart.
Itâ€™s an example of the kinds of insights that can be obtained from implantable electrical stimulation devices, which can record signals from seizures inside the brain over long periods of time (more than a year).
As the authors write, â€œthe technology can record brain activity while the patient is in a more naturalistic environment than a hospital, becoming an invasive ambulatory EEG.â€ Read more
MicroRNAs have emerged as important master regulators in cells, since each one can shut down several target genes. Riding on top of the master regulators is Drosha, the RNA-cutting enzyme that initiates microRNA processing in the nucleus. Drosha and its relative Dicer have been attracting attention in cancer biology, because they are thought to beÂ behind a phenomenon where cancerous cells can â€œinfectâ€ their healthy neighbors via tiny membrane-clothed packets called exosomes.
At Emory, pharmacologist Zixu Mao and colleagues recently published in Molecular Cell their findings that Drosha is regulated by stress (experimentally: heat or peroxide) through p38 MAP kinase.
Our recent news item on Emory pathologist Keqiang Ye’s obesity-related researchÂ (Molecule from trees helps female mice only resist weight gain) understatesÂ how many disease models the proto-drugÂ he and his colleagues have discovered, 7,8-dihydroxyflavone, can be beneficial in.Â We doÂ mentionÂ that Ye’s partners in Australia and Shanghai are applying to begin phase IÂ clinical trials with a close relative of 7,8-dihydroxyflavone in neurodegenerative diseases.
Everything is connected, especially in the brain. A protein called BAI1 involved in limiting the growth of brain tumors is also critical for spatial learning and memory, researchers have discovered.
Mice missing BAI1 have trouble learning and remembering where they have been. Because of the loss of BAI1, their neurons have changes in how they respond to electrical stimulation, and subtle alterations in parts of the cell needed for information processing.
Erwin Van Meir, PhD, and his colleagues at Winship Cancer Institute of Emory University have been studying BAI1 (brain-specific angiogenesis inhibitor 1) for several years. Part of the BAI1 protein can stop the growth of new blood vessels, which growing cancers need. Normally highly active in the brain, the BAI1 gene is lost or silenced in brain tumors, suggesting that it acts as a tumor suppressor.
The researchers were surprised to find that the brains of mice lacking the BAI1 gene looked normal anatomically. They didnâ€™t develop tumors any faster than normal, and they didnâ€™t have any alterations in their blood vessels, which the researchers had anticipated based on BAI1â€™s role in regulating blood vessel growth. What they did have was problems with spatial memory.
In the 1990s, neuroscientists identified a class of drugs that showed promise in the area of stroke. NMDA receptor antagonists could limit damage to the brain in animal models of stroke. But one problem complicated testing the drugs in a clinical setting: the side effects included disorientation and hallucinations.
Now researchers have found a potential path around this obstacle. The results were published in Neuron.
â€œWe have found neuroprotective compounds that can limit damage to the brain during ischemia associated with stroke and other brain injuries, but have minimal side effects,â€ says senior author Stephen Traynelis, PhD, professor of pharmacology at Emory University School of Medicine.
â€œThese compounds are most active when the pH is lowered by biochemical processes associated with injury of the surrounding tissue. This is a proof of concept study that shows this mechanism of action could potentially be exploited clinically in several conditions, such as stroke, traumatic brain injury and subarachnoid hemorrhage.â€ Read more
A new paper in PNAS from geneticist Steve Warren and colleagues illustratesÂ the complexity of the protein disrupted in fragile X syndrome. It touches on how proposed drug therapies that address one aspect of fragile X syndrome may not be able to compensate for all of them. [For a human side of this story, read/listen to this recent NPR piece from Jon Hamilton.]
Fragile X syndrome is the most common single-gene disorder responsible for intellectual disability. Most patients with fragile X syndrome inherit it because a repetitive stretch of DNA, which is outside the protein-coding portion of the fragile X gene, is larger than usual. The expanded number of CGG repeats silences the entire gene.
However, simple point mutations affecting the fragile X protein are possible in humans as well. In the PNAS paper, Warrenâ€™s team describes what happens with a particularly revealing mutation, which allowed researchers to dissect fragile X proteinâ€™s multifaceted functions. Read more