Second in a two-part series on nerve regeneration. Read part 1.
The search for therapies to spur regeneration after spinal cord injury, stroke and other central nervous system injuries hasn’t been all that successful to date. Getting nerve fibers (axons) to regenerate in mammals, typically lab mice, has often involved manipulating oncogenes or tumor suppressor genes to encourage growth, a move that could greatly increase a person’s risk of cancer.
In the U.S. alone, an estimated 30 million Americans suffer from a rare disorder. Many of them never receive a diagnosis, and often find themselves on a lonely journey, going from doctor to doctor and test to test, sometimes for many years, with no explanation for their symptoms.
How many people fall in the “undiagnosed” category is unclear, but in its first six years, the NIH’s Undiagnosed Diseases Program has received more than 10,000 inquiries. Without a diagnosis, it’s often difficult to qualify for insurance coverage, receive coordinated care or even connect with a support group.
What if the work of solving these medical mysteries could be crowd-sourced? That’s the goal of CLARITY Undiagnosed, an international challenge launching today in which scientific teams can compete to provide answers for five families with undiagnosed conditions. (Deadline for applications: June 11).
It may seem counterintuitive that your ability to tell different sounds apart would have anything to do with your ability to read or handle cognitive challenges. But that’s exactly what the lab of Nadine Gaab, PhD, has been showing.
Gaab discussed the research during a recent Longwood Seminar on Music as Medicine at Harvard Medical School:
The Gaab Lab has amassed an impressive body of work showing that auditory processing impairments correlate with developmental dyslexia, and that people who can detect tiny differences between sounds seem to do better both as musicians and as readers.
Protein production by the clock: mouse over to learn more. (Illustration: Yana Payusova, used with permission.)
Second in a two-part series on circadian biology and disease. Read part 1.
We are oscillating beings. Life itself arose among the oscillations of the waves and the oscillations between darkness and light. The oscillations are carried in our heartbeats and in our circadian sleep patterns.
A new study in Cell shows how these oscillations reach all the way down into our cells and help mastermind the timing of protein production.
When you go into Netflix to choose a movie or Amazon to buy a book, they’re ready with proactive suggestions for your next purchase, based on your past history. Isaac Kohane, MD, PhD, would like to see something similar happening in medicine, where today, patients often find themselves repeating their medical history “again and again to every provider,” as Kohane recently told Harvard Medicine.
“Medicine as a whole is a knowledge-processing business that increasingly is taking large amounts of data and then, in theory, bringing that information to the point of care so that doctor and patient have a maximally informed visit,” says Kohane, chair of informatics at Boston Children’s Hospital and co-director of the Center for Biomedical Informatics at Harvard Medical School.
Brain tumors, traumatic head injury and a number of brain and nervous system conditions can cause pressure to build up inside the skull. As intracranial pressure (ICP) rises, it can compress the brain and result in swelling of the optic nerves, damaging brain tissue and causing irreversible vision loss.
That’s what nearly happened to a 13-year-old boy who had three weeks of uncontrolled headaches and sudden double vision. His neuro-ophthalmologist at Boston Children’s Hospital, Gena Heidary, MD, PhD, found reduced vision in the right eye, along with poor peripheral vision, an enlarged blind spot and swelling of both optic nerves.
As Heidary suspected, he had idiopathic intracranial hypertension, a condition that can raise ICP both in children and adults. Heidary performed an operation around the optic nerve to relieve the pressure, and vision in the boy’s right eye gradually improved, though not completely. Heidary has had to monitor his ICP ever since to protect his visual system from further irreversible damage.
Unfortunately, such monitoring currently is pretty invasive.
Nerve regeneration. From Santiago Ramón y Cajal’s “Estudios sobre la degeneración y regeneración del sistema nervioso” (1913-14). Via Scholarpedia.
Researchers have tried for a century to get injured nerves in the brain and spinal cord to regenerate. Various combinations of growth-promoting and growth-inhibiting molecules have been found helpful, but results have often been hard to replicate. There have been some notable glimmers of hope in recent years, but the goal of regenerating a nerve fiber enough to wire up properly in the brain and actually function again has been largely elusive.
“The majority of axons still cannot regenerate,” says Zhigang He, PhD, a member of the F.M. Kirby Neurobiology Center at Boston Children’s Hospital. “This suggests we need to find additional molecules, additional mechanisms.”
Microarray analyses—which show what genes are transcribed (turned on) in injured nerves—have helped to some extent, but the plentiful leads they turn up are hard to analyze and often don’t pan out. The problem, says Judith Steen, PhD, who runs a proteomics lab at the Kirby Center, is that even when the genes are transcribed, the cell may not actually build the proteins they encode.
That’s where proteomics comes in. “By measuring proteins, you get a more direct, downstream readout of the system,” Steen says.
When a nurse gives a complex medication at the bedside, a second nurse must come in to observe and verify the dose. But flagging down a nurse on a busy hospital floor can be pretty challenging, especially when the nurse has to “suit up” because of infection control precautions in the patient’s room. During a Nursing Morbidity and Mortality (M&M) Conference at Boston Children’s Hospital, a group of nurses expressed concern that this arrangement could potentially jeopardize safety. “We thought we should be able to do better,” says project co-developer Jennifer Taylor, MSEd, BSN, RN-BC, CPN.
Preterm infants in neonatal intensive care units, particularly those with catheters and intravenous lines, are at high risk for bacteremia—bloodstream infections that can cause lasting brain injury. A new study may change how people think about these infections, suggesting that inflammation is as important to address as the infection itself.
“There has been a lot of indirect epidemiologic evidence for a link between bacteremia, inflammation and cerebral injury, but it showed only a correlation, not causation,” says Levy. “Here we demonstrate directly in an animal model that inflammation alone can cause brain injury in newborns with bacteremia, even without entry of the bacteria to the central nervous system.”
Severe social and emotional deprivation in early life is written into our biochemical stress responses. That’s the latest learning from the long-running Bucharest Early Intervention Project (BEIP), which began in 2000 and has been tracking severely neglected Romanian children in orphanages. Some of these children were randomly picked to be placed with carefully screened foster care families, and they’ve been compared with those left behind ever since.
While studies in rodents have linked early-life adversity with hyper-reactivity of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, the relationship has been harder to pin down in humans. BEIP’s study, involving almost 140 children around the age of 12, had children perform potentially stressful tasks, including delivering a speech before teachers, receiving social feedback from other children and playing a computer game that malfunctioned partway through.
Unlike the rodents, the institutionalized children had blunted responses in the sympathetic nervous system, which is associated with the “fight or flight” response, and in the HPA axis, which regulates production of the stress hormone cortisol. The researchers note that this dulled physiologic response has been linked to health problems, including chronic fatigue, pain syndrome and auto-immune conditions, as well as aggression and behavioral problems.