4/27/2013

Tests on Hereditary Diseases

Scientists at the University of Medicine and Dentistry of New Jersey-New Jersey Medical School (UMDNJ-NJMS) have developed new DNA sequencing tests that hold significant promise for decreasing costs associated with diagnosing cancer and hereditary diseases, including cystic fibrosis.

According to the Cystic Fibrosis Foundation web site, "More than 10 million Americans are symptomless carriers of the defective CF gene." This chronic disease impacts the lungs and the digestive system. It occurs when a child inherits one defective CF gene from each parent. Statistics show New Jersey averages 125,000 births of children who are diagnosed with cystic fibrosis annually.Officials at the New Jersey Department of Health approved the use of the new Cystic Fibrosis (CF) Carrier and Diagnosis Test, which was created at the Institute for Genomic Medicine at UMDNJ-NJMS. Using a semiconductor mechanism that was developed by San Francisco-based Ion Torrent, the microchip tests the entire gene for mutations. IGM now offers this certified Clinical Diagnostic Laboratory service for hospitals as well as obstetrics and gynecology practices throughout the Garden State.
"We believe the adaptation of this new sequencing technology will drastically improve our ability to analyze genetic disorders," said Marvin N. Schwalb, PhD, director of the Institute for Genomic Medicine. "Traditional CF sequencing testing costs thousands of dollars making the test unavailable for carrier screening. This new test costs less than $200. Most importantly, the genetic carrier test we developed improves the diagnosis rate to 98 percent. While the test provides significant improvement for all populations, the improved rate is particularly valuable for minorities because current carrier screening methods only detects approximately 65% of mutations in these populations."
The new technology provides many advances including the ability to test as many as 96 samples on a single platform and the fact that the equipment cost 1/10 as much as the previous technology.
IGM has developed another test, which was also approved by the NJHSS, for mitochondrial DNA. Mutations in mitochondria cause a wide variety of diseases, such eye and neuromuscular system disorders and possible cancer.
Schwalb, a professor of Pediatrics, Microbiology and Molecular Genetics at NJMS, said, "We are proud of the fact that the IGM is a world leader in the advancement of genetic diagnosis. DNA sequencing will keep us very busy for a while. In the state of New Jersey, there is nothing that compares to this advancement and this is just the beginning."
Source: University of Medicine and Dentistry of New Jersey (UMDNJ) (2012, August 16). Researchers develop DNA sequencing tests for hereditary diseases. ScienceDaily. Retrieved April 27, 2013, from http://www.sciencedaily.com/releases/2012/08/120816170309.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29

4/25/2013

Gut bacteria linked to obesity

Researchers at the University of Maryland School of Medicine have identified 26 species of bacteria in the human gut microbiota that appear to be linked to obesity and related metabolic complications. These include insulin resistance, high blood sugar levels, increased blood pressure and high cholesterol, known collectively as "the metabolic syndrome," which significantly increases an individual’s risk of developing diabetes, cardiovascular disease and stroke.

"We identified 26 species of bacteria that were correlated with obesity and metabolic syndrome traits such as body mass index (BMI), triglycerides, cholesterol, glucose levels and C-reactive protein, a marker for inflammation," says the senior author, Claire M. Fraser, Ph.D., professor of medicine and microbiology and immunology and director of the Institute for Genome Sciences (IGS) at the University of Maryland School of Medicine. "We can’t infer cause and effect, but it’s an important step forward that we're starting to identify bacteria that are correlated with clinical parameters, which suggests that the gut microbiota could one day be targeted with medication, diet or lifestyle changes."The results of the study, which analyzed data from the Old Order Amish in Lancaster County, Pa., are being published online on Aug. 15, 2012, in PLOS ONE, which is published by the Public Library of Science (PLOS One). The study was funded by the National Institutes of Health (NIH). (UH2/UH3 DK083982, U01 GM074518 and P30 DK072488)
Dr. Fraser says that additional research, including an interventional study with the Amish, is essential. "We can look at whether these bacteria change over time in a given individual or in response to diet or medication," she says.
Dr. Fraser notes that the research team, led by Margaret L. Zupancic, Ph.D., then a postdoctoral fellow at IGS, also found an apparent link between the gut bacteria and inflammation, which is believed to be a factor in obesity and many other chronic diseases. "This is one of the first studies of obesity in humans to make a link between inflammatory processes and specific organisms that are present in the GI tract," Dr. Fraser says, noting that participants with metabolic syndrome who had elevated serum markers associated with inflammation tended to have the lowest levels of good bacteria that have been reported previously to have anti-inflammatory properties.
The study is the result of an ongoing collaboration between Dr. Fraser and Alan R. Shuldiner, M.D., in connection with the NIH’s Human Microbiome Project, which seeks to characterize microbial communities in the body. Dr. Shuldiner, associate dean for personalized medicine and director of the Program in Personalized and Genomic Medicine at the University of Maryland School of Medicine, operates an Amish research clinic in Lancaster Pa. Over the past 20 years, he and his research team have conducted more than a dozen studies with the Amish, looking for genes that may cause common diseases, such as diabetes, osteoporosis and cardiovascular disease.
"The Old Order Amish are ideal for such studies because they are a genetically homogenous population descended from a few founder families and have a similar rural lifestyle," Dr. Shuldiner, the John L. Whitehurst Professor of Medicine, says. "We believe the results of this study are relevant to a broader population because the clinical characteristics of obesity and its complications in the Amish are no different from the general Caucasian population," he says.
E. Albert Reece, M.D., Ph.D., M.B.A., vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor and dean of the University of Maryland School of Medicine, says, "Obesity and its related complications have become a critical public health concern, and the number of people who are now considered obese or overweight has skyrocketed. Dr. Fraser and Dr. Shuldiner are two of our most senior research-scientists and leaders in their respective fields. This study provides valuable insights into the role the bacteria in our bodies may play in obesity and the metabolic syndrome. We may ultimately be able to target the gut microbiome to help prevent or mitigate risk factors for a number of diseases."
The researchers analyzed the bacteria in fecal samples of 310 members of the Old Order Amish community, using a process that enables them to identify a marker gene that serves as a bar code for each type of bacteria. Participants in the study ranged from lean to overweight to obese; some of the obese participants also had features of the metabolic syndrome. "Our hypothesis was that we would see a different composition in the gut microbiota in lean vs. obese individuals and possibly in individuals who were obese but also had features of the metabolic syndrome."
They discovered that every individual possessed one of three different communities of interacting bacteria, each characterized by a dominant bacterial genus. Neither BMI nor any metabolic syndrome trait was specifically associated with any of these communities. Instead, differing levels of 26 less abundant bacterial species present in all individuals appeared to be linked to obesity and certain features of the metabolic syndrome.
Interestingly, researchers also analyzed people's gut bacteria by their occupation and found that those who had regular contact with livestock, such as farmers and their wives, had bacterial communities dominated by Prevotella, a type of bacteria that is also abundant in the gut microbiota of cattle and sheep. "These findings suggest that environmental exposure may play a role in determining the composition of the gut microbiota in humans," Dr. Fraser says.

University of Maryland Medical Center (2012, August 15). Gut bacteria linked to obesity and metabolic syndrome identified. ScienceDaily. Retrieved April 26, 2013, from http://www.sciencedaily.com­/releases/2012/08/120815174902.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29

4/24/2013

Scientists Can Now Block Heroin, Morphine Addiction

In a major breakthrough, an international team of scientists has proven that addiction to morphine and heroin can be blocked, while at the same time increasing pain relief.



Laboratory studies have shown that the drug (+)-naloxone (pronounced: PLUS nal-OX-own) will selectively block the immune-addiction response.The team from the University of Adelaide and University of Colorado has discovered the key mechanism in the body's immune system that amplifies addiction to opioid drugs.
The results -- which could eventually lead to new co-formulated drugs that assist patients with severe pain, as well as helping heroin users to kick the habit -- will be published August 16 in the Journal of Neuroscience.
"Our studies have shown conclusively that we can block addiction via the immune system of the brain, without targeting the brain's wiring," says the lead author of the study, Dr Mark Hutchinson, ARC Research Fellow in the University of Adelaide's School of Medical Sciences.
"Both the central nervous system and the immune system play important roles in creating addiction, but our studies have shown we only need to block the immune response in the brain to prevent cravings for opioid drugs."
The team has focused its research efforts on the immune receptor known as Toll-Like receptor 4 (TLR4).
"Opioid drugs such as morphine and heroin bind to TLR4 in a similar way to the normal immune response to bacteria. The problem is that TLR4 then acts as an amplifier for addiction," Dr Hutchinson says.
"The drug (+)-naloxone automatically shuts down the addiction. It shuts down the need to take opioids, it cuts out behaviours associated with addiction, and the neurochemistry in the brain changes -- dopamine, which is the chemical important for providing that sense of 'reward' from the drug, is no longer produced."
Senior author Professor Linda Watkins, from the Center for Neuroscience at the University of Colorado Boulder, says: "This work fundamentally changes what we understand about opioids, reward and addiction. We've suspected for some years that TLR4 may be the key to blocking opioid addiction, but now we have the proof.
"The drug that we've used to block addiction, (+)-naloxone, is a non-opioid mirror image drug that was created by Dr Kenner Rice in the 1970s. We believe this will prove extremely useful as a co-formulated drug with morphine, so that patients who require relief for severe pain will not become addicted but still receive pain relief. This has the potential to lead to major advances in patient and palliative care," Professor Watkins says.
The researchers say clinical trials may be possible within the next 18 months.
This study has been funded by the National Institute on Drug Abuse (NIDA) in the United States and the Australian Research Council (ARC).
Source: University of Adelaide (2012, August 14). Scientists can now block heroin, morphine addiction. ScienceDaily. Retrieved April 24, 2013, from http://www.sciencedaily.com­/releases/2012/08/120814213246.htm

4/23/2013

An Artificial Retina With the Capacity to Restore Normal Vision

Two researchers at Weill Cornell Medical College have deciphered a mouse's retina's neural code and coupled this information to a novel prosthetic device to restore sight to blind mice. The researchers say they have also cracked the code for a monkey retina -- which is essentially identical to that of a human -- and hope to quickly design and test a device that blind humans can use.



The lead researcher, Dr. Sheila Nirenberg, a computational neuroscientist at Weill Cornell, envisions a day when the blind can choose to wear a visor, similar to the one used on the television show Star Trek. The visor's camera will take in light and use a computer chip to turn it into a code that the brain can translate into an image.The breakthrough, reported in theProceedings of the National Academy of Sciences (PNAS), signals a remarkable advance in longstanding efforts to restore vision. Current prosthetics provide blind users with spots and edges of light to help them navigate. This novel device provides the code to restore normal vision. The code is so accurate that it can allow facial features to be discerned and allow animals to track moving images.
"It's an exciting time. We can make blind mouse retinas see, and we're moving as fast as we can to do the same in humans," says Dr. Nirenberg, a professor in the Department of Physiology and Biophysics and in the Institute for Computational Biomedicine at Weill Cornell. The study's co-author is Dr. Chethan Pandarinath, who was a graduate student with Dr. Nirenberg and is currently a postdoctoral researcher at Stanford University.
This new approach provides hope for the 25 million people worldwide who suffer from blindness due to diseases of the retina. Because drug therapies help only a small fraction of this population, prosthetic devices are their best option for future sight. "This is the first prosthetic that has the potential to provide normal or near-normal vision because it incorporates the code," Dr. Nirenberg explains.
Discovering the Code
Normal vision occurs when light falls on photoreceptors in the surface of the retina. The retinal circuitry then processes the signals from the photoreceptors and converts them into a code of neural impulses. These impulses are then sent up to the brain by the retina's output cells, called ganglion cells. The brain understands this code of neural pulses and can translate it into meaningful images.
Blindness is often caused by diseases of the retina that kill the photoreceptors and destroy the associated circuitry, but typically, in these diseases, the retina's output cells are spared.
Current prosthetics generally work by driving these surviving cells. Electrodes are implanted into a blind patient's eye, and they stimulate the ganglion cells with current. But this only produces rough visual fields.
Many groups are working to improve performance by placing more stimulators into the patient's eye. The hope is that with more stimulators, more ganglion cells in the damaged tissue will be activated, and image quality will improve.
Other research teams are testing use of light-sensitive proteins as an alternate way to stimulate the cells. These proteins are introduced into the retina by gene therapy. Once in the eye, they can target many ganglion cells at once.
But Dr. Nirenberg points out that there's another critical factor. "Not only is it necessary to stimulate large numbers of cells, but they also have to be stimulated with the right code -- the code the retina normally uses to communicate with the brain."
This is what the authors discovered -- and what they incorporated into a novel prosthetic system.
Dr. Nirenberg reasoned that any pattern of light falling on to the retina had to be converted into a general code -- a set of equations -- that turns light patterns into patterns of electrical pulses. "People have been trying to find the code that does this for simple stimuli, but we knew it had to be generalizable, so that it could work for anything -- faces, landscapes, anything that a person sees," Dr. Nirenberg says.
Vision = Chip Plus Gene Therapy
In a eureka moment, while working on the code for a different reason, Dr. Nirenberg realized that what she was doing could be directly applied to a prosthetic. She and her student, Dr. Pandarinath, immediately went to work on it. They implemented the mathematical equations on a "chip" and combined it with a mini-projector. The chip, which she calls the "encoder" converts images that come into the eye into streams of electrical impulses, and the mini-projector then converts the electrical impulses into light impulses. These light pulses then drive the light-sensitive proteins, which have been put in the ganglion cells, to send the code on up to the brain.
The entire approach was tested on the mouse. The researchers built two prosthetic systems -- one with the code and one without. "Incorporating the code had a dramatic impact," Dr. Nirenberg says. "It jumped the system's performance up to near-normal levels -- that is, there was enough information in the system's output to reconstruct images of faces, animals -- basically anything we attempted."
In a rigorous series of experiments, the researchers found that the patterns produced by the blind retinas in mice closely matched those produced by normal mouse retinas.
"The reason this system works is two-fold," Dr. Nirenberg says. "The encoder -- the set of equations -- is able to mimic retinal transformations for a broad range of stimuli, including natural scenes, and thus produce normal patterns of electrical pulses, and the stimulator (the light sensitive protein) is able to send those pulses on up to the brain."
"What these findings show is that the critical ingredients for building a highly-effective retinal prosthetic -- the retina's code and a high resolution stimulating method -- are now, to a large extent, in place," reports Dr. Nirenberg.
Dr. Nirenberg says her retinal prosthetic will need to undergo human clinical trials, especially to test safety of the gene therapy component, which delivers the light-sensitive protein. But she anticipates it will be safe since similar gene therapy vectors have been successfully tested for other retinal diseases.
"This has all been thrilling," Dr. Nirenberg says. "I can't wait to get started on bringing this approach to patients."
The study was funded by grants from the National Institutes of Health and Cornell University's Institute for Computational Biomedicine.
Both Drs. Nirenberg and Pandarinath have a patent application for the prosthetic system filed through Cornell University.
Source: Weill Cornell Medical College (2012, August 14). An artificial retina with the capacity to restore normal vision. ScienceDaily. Retrieved April 23, 2013, from http://www.sciencedaily.com­/releases/2012/08/120814213326.htm

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