New Video Shows Communication Between Brain Cells
An NIH researcher has captured video images of a previously unknown form of communication between brain cells that might hold clues to the way learning shapes the brain. The videos, offered as a resource for educators teaching high school, undergraduate, and graduate students, are available on the Web.
These newly recorded signals are emitted along the length of nerve fibers. Earlier research has documented the transmission of signals across the synapse. The new videos show that when neurons communicate, electrical signals emitted along the length of neurons stimulates nearby brain cells known as glia, or glial cells. As a result, the glial cells begin making a substance called myelin, which coats the nerve fibers and allows electrical charges to travel with greater speed through the brain’s networks.
Other studies have shown that the process of myelination underlies learning and is crucial for the development of new skills. Additional research might help clarify how signaling between neurons and glial cells triggers myelination and influences skill development, according to R Douglas Fields, PhD, of the National Institute of Child Health and Human Development’s (NICHD ) Nervous Systems Development and Plasticity Section.
The teaching resource on the website features short video clips that document these previously unknown non-synaptic signals.
“For the last 100 years researchers have studied how information traverses the brain, crossing synapses and traveling from one nerve cell to the next,” said Fields. “We can now see another type of communication, in which cells along a neuron’s length can sense the chemical signals the neuron releases.”
To detect these signals, Fields observed neurons under a microscope. Nerve fibers, or axons, are long projections that stretch between neurons. The longest human axon stretches from the base of the spine to the big toe. Working with the corresponding neuron of mice, Fields stimulated the neuron with electrical charges and recorded his findings in three videos now available on the Web. The videos can be viewed here.
Level of Tumor Protein Indicates Cancer’s Chance of Spreading
Researchers at NIH and the University of Hong Kong have discovered that high levels of a particular protein in cancer cells are a reliable indicator that a cancer will spread. By measuring the protein’s genetic material in tumors that had been surgically removed from patients, along with measuring the genetic material from surrounding tissue, the researchers could predict at least 90% of the time whether a cancer would spread within two years. The findings raise the long-term possibilities of new tests to gauge the likelihood that a cancer will spread and, ultimately, of a treatment that could prevent cancer from spreading.
The protein, known as CPE-delta N, is a form of carboxypeptidase E (CPE). Ordinarily, CPE is involved in processing insulin and other hormones. CPE-delta N, a variant of CPE, was present in high amounts in tumors that had spread and, to a much lesser degree, in surrounding tissues.
“Testing for CPE-delta N, if combined with existing diagnostic methods, offers the possibility of more accurately estimating the chances that a cancer will spread,” said Alan E Guttmacher, MD, director of the NICHD, which supported the study. “Conceivably, a patient’s CPE-delta N levels could be a key guide in individualizing their cancer care to improve outcome.”
The researchers estimated the likelihood of metastasis in tumor samples and tissues from patients with liver cancer and two rare tumors, pheochromocytoma and paraganglioma. They found that tumor samples from patients whose cancers had later metastasized had elevated levels of CPE-delta N.
Tests indicating high levels of the protein predicted the spread of a cancerous tumor even when conventional staging—diagnostic techniques to gauge the extent and seriousness of a cancer—indicated that spread was unlikely. The finding raises the possibility that testing for CPE-delta N might be used in combination with conventional staging to further refine treatment. For example, if conventional staging indicated that a cancer was unlikely to spread, but a patient’s tumor had high CPE-delta N levels, that patient might be referred for more intensive therapies normally reserved for higher stage cancers.
The researchers tested for CPE-delta N indirectly, by measuring levels of a molecule that assists in manufacturing the protein. RNA works with the information in a gene to make a particular protein — in this case, CPE-delta N.
In an analysis of tissue from 99 patients with liver cancer, the researchers compared the amount of CPE-delta N RNA from the patients’ tumors with the RNA levels in surrounding tissue. The researchers found that when the level of CPE delta-N RNA in tumors was more than twice that in the surrounding tissue, the cancer was highly likely to return or to metastasize within two years. At or below this threshold level, the cancer was much less likely to recur. Using this threshold measure, the researchers accurately predicted metastasis or recurrence in more than 90% of cases. Conversely, their predictions that tumors would not return in the two-year period were accurate 76% of the time.
Surveillance Ordered for TMJ Implants
FDA ordered three manufacturers of temporomandibular joint (TMJ) implants to conduct postmarket surveillance studies to determine the length of time before the implants are removed or replaced due to pain or other reasons. The TMJ connects the lower jaw (mandible) to the temporal bone in the skull. A person may have an implant to replace the socket in the temporal bone or the rounded edge of the lower jaw that glides in the temporal bone socket because of an injury, arthritis, physical abnormality, or lost mobility.
The three manufacturers, TMJ Solutions, TMJ Medical, and Biomet Microfixation, make all of the currently approved TMJ devices marketed in the United States. The companies will have 30 days to submit a study plan, which will need to be approved by the agency before any postmarket studies can begin.
TMJ implants can also be used to treat temporomandibular disorder (TMD) that has not responded to more conservative treatments such as limiting jaw movement, soft diet, jaw splint or adjustments, medicine to reduce pain, or physical therapy.
The FDA analyzed TMJ implant-related adverse event reports submitted over the last six years. The analysis described a substantial number of patients who had implants replaced within three years or less after implantation because of extreme pain. This is considerably shorter than the expected minimum five-year life span of the device, based on premarket mechanical testing.
TMJ implant manufacturers were required to collect postmarket data on their implants as part of the approval process. However, the data collected did not adequately address the timing or reasons for replacement, and the studies lost contact over the years with many of the enrolled patients.
The TMJ implant postmarket surveillance studies must address: time between initial implant and removal; association between patient diagnosis and the timeframe between implant and removal; for replacement implants, the time between implant and subsequent removal or replacement; reasons for removal or replacement; associations between patient demographic and clinical data and the need for removal/replacement; and assessment of devices that have been removed from patients. As part of its review, the FDA will consider whether labeling changes, additional preclinical and clinical testing requirements, or other regulatory actions are necessary.
New App Allows Doctors to View Medical Images on iPhone® and iPad®
A new mobile radiology application that will allow physicians to view medical images on the iPhone and iPad manufactured by Apple Inc has been cleared by FDA for use.
The application is the first approved by FDA for viewing images and making medical diagnoses based on CT, MRI, and nuclear medicine technology, such as positron emission tomography. It is not intended to replace full workstations and is indicated for use only when there is no access to a workstation.
Radiology images taken in the hospital or physician’s office are compressed for secure network transfer then sent to the appropriate portable wireless device via software called Mobile MIM. Mobile MIM, manufactured by Cleveland-based MIM Software Inc, allows the physician to measure distance on the image and image intensity values, and to display measurement lines, annotations, and regions of interest.
In its evaluation, the FDA reviewed performance test results on various portable devices. These tests measured luminance, image quality, and noise in accordance with international standards and guidelines. The FDA also reviewed results from demonstration studies with qualified radiologists under different lighting conditions. All participants agreed that the device was sufficient for diagnostic image interpretation under the recommended lighting conditions.
The display performance of mobile devices can experience significant variations in luminance levels even between mobile devices of the same model. The Mobile MIM application includes sufficient labeling and safety features to mitigate the risk of poor image display due to improper screen luminance or lighting conditions. The device includes an interactive contrast test in which a small part of the screen is a slightly different shade than the rest of the screen. If the physician can identify and tap this portion of the screen, then the lighting conditions are not interfering with the physician’s ability to discern subtle differences in contrast. In addition, a safety guide is included within the application.
New Mental Health Campaign Targets People Affected by Oil Spill
SAMHSA, in collaboration with the Ad Council, has expanded its efforts to provide information, support, and resources to individuals and families affected by the Deepwater Horizon oil spill.
“While the immediate crisis is over, many Gulf Coast residents continue to need support as they work to rebuild their lives after the Deepwater Horizon oil spill. It is natural for some people to need help over time in dealing with the emotional trauma and distress experienced from such an event and associated losses,” said SAMHSA Administrator Pamela S Hyde, JD.
The campaign is designed to raise awareness of the early warning signs of serious emotional distress, and to provide access to free resources to those affected in the Gulf state region. The television PSA, featuring Surgeon General Regina Benjamin, and other PSAs aim to help those living in the Gulf states get the assistance they may need to treat and alleviate long term psychological distress.
“For many who live on the Gulf Coast, this disaster has affected us very deeply,” said Benjamin. “We want anyone who is feeling distressed to know that getting help can be as simple as making a phone call or sending a text message.”
The new television, English and Spanish radio ads, and outdoor PSA’s were created by Grey New York, Clear Channel Creative Services Group, and Lamar Advertising through the Ad Council. The PSAs direct audiences to call a toll-free number (1-800-985-5990), or text TALKWITHUS to 66746 for a safe, confidential way to receive free counseling, information, and support from trained professionals (Standard text messaging and data rates apply). The toll-free Oil Spill Distress Helpline, funded by SAMHSA, links callers to local crisis centers, where local and trained professionals answer the calls and provide confidential assistance. Haitian Creole and Spanish-language operators are also available.