Accompanying Kai Kupferschmidtâ€™s July 3 feature in Science, which discusses a current revival of clinical research on hallucinogens such as LSD and psilocybin, was a curious historical photo. The 1955 copyrightedÂ photo depicts pharmacologist Harry Williams squirting LSD into the mouth of Carl Pfeiffer, chair of pharmacology at Emory during the 1950â€™s. Read more
It’s not sleep apnea. It’s not narcolepsy. Hypersomnia is a different kind of sleep disorder. There’s even an “apples and oranges” T-shirt (see below) that makes that point.
This weekend, your correspondent attended a patient-organized Living with Hypersomnia conference. One of the main purposes of the conference was to update sufferers and supporters on the state of research at Emory and elsewhere, but there was also a lot of community building — hence the T-shirts.
The story of how sleep took over one young lawyer’s life, and how her life was then transformed by flumazenil, a scarce antidote to sleeping pills she was not taking, has received plenty of attention.
Now an increasing number of people are emerging who have a condition similar to Anna Sumner’s, and several questions need answers. Read more
This is a continuation of previous posts on individualized treatment for infantile-onset epilepsy, made possible by Emory scientists Stephen Traynelis and Hongjie Yuanâ€™s collaboration with the NIH Undiagnosed Diseases Program. A companion paper containing some clinical details was recently published in Annals of Clinical and Translational Neurology.
Memantine, which was found to be effective for this particular child, is normally used to treat symptoms of Alzheimerâ€™s disease. He has a mutation in a gene encoding a NMDA receptor, an important signaling molecule in the brain, which hyperactivates the receptor. Treatment with memantine reduced his seizure frequency from 11 per week to three per week, and eliminated one type of seizure, myoclonic jerks. It allowed doctors to taper off conventional anticonvulsant drugs, which were having little effect anyway. His cognitive ability has remained unchanged.
The team also discovered that the compound dextromethorphan, found in many over-the-counter cough medicines, was effective in the laboratory in counteracting the effects of a GRIN2A mutation found in another patient. However, these effects were mutually exclusive, because the molecular effects of the mutations are different; memantine helps L812M, while dextromethorphan helps N615K.
Yuan and Traynelis report they have an Fake Oakleys ongoing collaboration with UDP investigators to analyze the effects of mutations in NMDA receptor genes. That means more intriguing case reports are coming, they say.
Tyler Pierson, MD, PhD, lead author of the clinical paper who is now at Cedars-Sinai Medical Center in Los Angeles, and David Adams, MD, PhD, senior staff clinician at NIH, provided some additional information on the patient in the study, shown here in a Q + A format. Read more
This is a continuation of the post from last week on the early-onset epilepsy patient, whom doctors were able to devise an individualized treatment for. The treatment was based on Emory research on the molecular effects of a mutation in the patientâ€™s GRIN2A gene, discovered through whole exome sequencing.*
For this patient, investigators were able to find the Ray Ban Baratas cause for a previously difficult to diagnose case, and then use a medication usually used for Alzheimerâ€™s disease (memantine) to reduce his seizure frequency.
Last week, I posed the question: how often do we move from a disease-causing mutation to tailored treatment? Read more
How often can doctors go from encountering a patient with a mysterious disease, to finding a mutation in a gene that causes that disease, to developing a treatment crafted for that mutation?
This is true personalized molecular medicine, but itâ€™s quite rare.
How rare this is, Iâ€™d like to explore more, but first I should explain the basics.
At Emory, Stephen Traynelis and Hongjie Yuan have been working with Tyler Pierson, David Adams, William Gahl, Cornelius Boerkoel and doctors at the National Institutes of Healthâ€™s Undiagnosed Diseases Program (UDP) to investigate the effects of mutations in the GRIN2A gene.
Their report on the molecular effects of one such mutation, which caused early-onset epilepsy and intractable seizures in a UDP patient, was recently published in Nature Communications.
With that information in hand, UDP investigators were able to repurpose an Alzheimerâ€™s medication as an anticonvulsant that was effective in reducing seizure frequency in that patient. [The details on that are still unpublished but coming soon.]
To help visualize lamellipodia, Adriana Simionescu-Bankston, a graduate student in Grace Pavlath’s lab, provided us with this photo of muscle cells. The red box shows an example of lamellipodia. Notice the edge of the cell, where the green color is more intense.
The green color comes from FITC-phalloidin, which stains F-actin, the Ray Ban outlet filaments that make up a large part of the cells’ internal skeleton. (Phalloidin is an actin-binding toxin originally isolated from death cap mushrooms, and FITC is what makes it green.) The blue color comes from DAPI, a dye that stains the DNA in the nucleus.
Simionescu-Bankston and Pavlath recently published a paper in the journal Developmental Biology, examining the function of a protein called Bin3 in muscle development and regeneration. They found that Bin3 appears to regulate lamellipodia formation; in mice that lack Bin3, muscle cells have fewer lamellipodia and the muscle tissues regenerate slower after injury. Bin3 is also important in the eye, since the “knockout” mice develop cataracts soon after birth.
Emory researchers led by pharmacologist Ellen Hess have identified a new molecular target in dystonia. Their findings, recently published in the Journal of Pharmacology and Experimental Therapeutics, could help doctors find drugs for treating the movement disorder.
Dystonia gives sufferers involuntary muscle contractions that cause rigid, twisting movements and abnormal postures. It is the third most common movement disorder, after tremor and Parkinsonâ€™s disease. Neurologists can sometimes use drugs to address the symptoms of dystonia but there is no cure.
A 2008 review by Hess (PDF) concludes that compared with other neurological disorders, â€œour understanding of the biology and potential treatments for dystonia is in its infancy.â€ Still, scientists have known for a while that the cerebellum, a region of the brain that regulates movement, is involved.
â€œWe focused on the cerebellum because studies in patients with dystonia often show that this part of the brain is more active, when examined by MRI,” Hess says. “The abnormal overactivity of the cerebellum is seen in patients with all different types of dystonia, so it seems to be a common hotspot. Our goal was to understand what might be causing the overactivity in mice because if we can stop the overactivity, we might be able to stop the dystonia.”
Hess and her colleagues discovered that drugs that stimulate AMPA receptors induce dystonia when introduced into the mouse cerebellum. Their results suggest that drugs that act in reverse, blocking AMPA receptors, could be used to treat dystonia.
Postdoctoral fellow Xueliang Fan is the first author of the paper. Emory neurologist H.A. Jinnah, director of a NIH-supported network of clinical research sites focusing on dystonia, is a co-author.
AMPA receptors are a subset of glutamate receptors, a large group of â€œreceiver dishesâ€ for excitatory signals in the brain. Fan performed a variety of experiments to show that AMPA receptor activity plays a specific role in generating dystonia. For example, drugs that affect other types of glutamate receptors did not induce dystonia. AMPA receptor blockers can also reduce dystonia in a genetic model, the â€œtotteringâ€ mouse.
Although pharmaceutical companies have already been testing AMPA receptor blockers as potential antiseizure drugs, caution is in order. AMPA receptor stimulators/ enhancers (or â€œampakinesâ€) have been identified as potential enhancers of learning and memory, so AMPA receptor blockers may interfere with those processes.
â€œOur results suggest that reducing AMPA receptor activity could help alleviate dystonia but we still have a lot of work to do before we know whether blocking AMPA receptor activity in patients will really help,” Hess says. “Since there arenâ€™t many drugs that act at AMPA receptors, one of our goals is to identify drugs that change the â€˜downstreamâ€™ effects of AMPA receptor activation. For example, we may be able to find other drug classes that change neuronal activity in the same way that AMPA receptor blockade changes activity.â€