Innovative hand-held lab-on-a-chip could streamline blood testing worldwide
July 31, 2011
Successfully tested in Rwanda, mChip diagnoses infectious diseases like HIV and syphilis at patients’ bedsides; new device could streamline blood testing worldwide
New York, NYJuly 31, 2011Samuel K. Sia, assistant professor of biomedical engineering at Columbia Engineering, has developed an innovative strategy for an integrated microfluidic-based diagnostic devicein effect, a lab-on-a-chipthat can perform complex laboratory assays, and do so with such simplicity that these tests can be carried out in the most remote regions of the world. In a paper published in Nature Medicine online on July 31, Sia presents the first published field results on how microfluidicsthe manipulation of small amounts of fluidsand nanoparticles can be successfully leveraged to produce a functional low-cost diagnostic device in extreme resource-limited settings.
Sia and his team performed testing in Rwanda over the last four years in partnership with Columbia’s Mailman School of Public Health and three local non-government organizations in Rwanda, targeting hundreds of patients. His device, known as mChip (mobile microfluidic chip), requires only a tiny finger prick of blood, effective even for a newborn, and givesin less than 15 minutesquantitative objective results that are not subject to user interpretation. This new technology significantly reduces the time between testing patients and treating them, providing medical workers in the field results that are much easier to read at a much lower cost. New low-cost diagnostics like the mChip could revolutionize medical care around the world.
“We have engineered a disposable credit card-sized device that can produce blood-based diagnostic results in minutes,” said Sia. “The idea is to make a large class of diagnostic tests accessible to patients in any setting in the world, rather than forcing them to go to a clinic to draw blood and then wait days for their results.”
Sia’s lab at Columbia Engineering has developed the mChip devices in collaboration with Claros Diagnostics Inc., a venture capital-backed startup that Sia co-founded in 2004. (The company has recently been named by MIT’s Technology Review as one of the 50 most innovative companies in the world.) The microchip inside the device is formed through injection molding and holds miniature forms of test tubes and chemicals; the cost of the chip is about $1 and the entire instrument about $100.
Sia hopes to use the mChip to help pregnant women in Rwanda who, while they may be suffering from AIDS and sexually transmitted diseases, cannot be diagnosed with any certainty because they live too far away from a clinic or hospital with a lab. “Diagnosis of infectious diseases is very important in the developing world,” said Sia. “When you’re in these villages, you may have the drugs for many STDs, but you don’t know who to give treatments to, so the challenge really comes down to diagnostics.” A version of the mChip that tests for prostate cancer has also been developed by Claros Diagnostics and was approved in 2010 for use in Europe.
Sia’s work also focuses on developing new high-resolution tools to control the extracellular environments around cells, in order to study how they interact to form human tissues and organs. His lab uses techniques from a number of different fields, including biochemistry, molecular biology, microfabrication, microfluidics, materials chemistry, and cell and tissue biology.
Sia was named one of the world’s top young innovators for 2010 by MIT’s Technology Review for his work in biotechnology and medicine, and by NASA as one of 10 innovators in human health and sustainability. In 2008, he received a CAREER award from the National Science Foundation that included a $400,000 grant to support his other research specialty in three-dimensional tissue engineering. A recipient of the Walter H. Coulter Early Career Award in 2008, Sia participated in the National Academy of Engineering’s U.S. Frontiers of Engineering symposium for the nation’s brightest young engineers in 2007. He earned his B.Sc. in biochemistry from the University of Alberta, and his Ph.D. in biophysics from Harvard University, where he was also a postdoctoral fellow in chemistry and chemical biology.
The mChip project has been supported by funding from the National Institutes of Health and Wallace Coulter Foundation.
Columbia Engineering
Columbia University’s Fu Foundation School of Engineering and Applied Science, founded in 1864, offers programs in nine departments to both undergraduate and graduate students. With facilities specifically designed and equipped to meet the laboratory and research needs of faculty and students, Columbia Engineering is home to NSF-NIH funded centers in genomic science, molecular nanostructures, materials science, and energy, as well as one of the world’s leading programs in financial engineering. These interdisciplinary centers are leading the way in their respective fields while individual groups of engineers and scientists collaborate to solve some of society’s more vexing challenges. http://www.engineering.columbia.edu/
Contact: Holly Evarts
holly@engineering.columbia.edu
212-854-3206
Columbia University
FDA should invest in developing a new regulatory framework to replace flawed 510(k) medical device clearance process
July 29, 2011
The U.S. Food and Drug Administration should gather the information needed to develop a new regulatory framework to replace the 35-year-old 510(k) clearance process for medical devices, says a new report from the Institute of Medicine. The 510(k) process lacks the legal basis to be a reliable premarket screen of the safety and effectiveness of moderate-risk Class II devices and cannot be transformed into one, concluded the committee that wrote the report.
FDA’s finite resources would be better invested in developing a new framework that uses both premarket clearance and improved postmarket surveillance of device performance to provide reasonable assurance of the safety and effectiveness of Class II devices throughout the duration of their use, the committee said. The agency should also ensure that the new process allows devices to reach the market in as rapid and least burdensome a fashion as possible. Read more
Study of golf swings pinpoints biomechanical differences between pros and amateurs
July 29, 2011
When it comes to hitting a golf ball hard, researchers at the Stanford University School of Medicine have identified several biomechanical factors that appear to separate the duffers from the pros.
For the first time, several key rotational-biomechanic elements of the golf stroke in its entirety, from backswing to follow-through, were analyzed, and then the data were used to generate benchmark curves, said Jessica Rose, PhD, associate professor of orthopaedic surgery and senior author of the study. She and her fellow researchers found that swing biomechanics were highly consistent among a group of professional players. At certain phases of their swings, their movements were almost indistinguishable from one another.
“The set of biomechanical factors we examined were selected to capture the essential elements of power generation,” Rose said. The lead author of the study is former Stanford medical student David Meister, MD.
The findings, scheduled to be published online July 29 in the Journal of Applied Biomechanics, could be used to help improve golfers’ ability to hit the ball farther and do so without increasing their risks of injury. The authors point to studies showing that improper swing biomechanics is the leading cause of golf-related injuries. They also cite studies showing that 26-52 percent of golf-related complaints involve lower-back injuries, 6-10 percent involve shoulder injuries and 13-36 percent involve wrist injuries.
“Over-rotation is one of the leading causes of back injury,” Rose added.
Researchers collected data for the study using an array of eight special digital cameras in the Motion & Gait Analysis Laboratory at Lucile Packard Children’s Hospital at Stanford. Using the same precise technology they typically use to analyze gait and upper limb movement disorders, they recorded three-dimensional motion images of the golf swings of 10 professional and five amateur male players. Among the five non-professional golfers, one was a college-level amateur with a handicap of 4; two were amateurs with handicaps of 15 and 30, respectively; and two were novices. Most of the professional players were alumni of the Stanford Men’s Golf Team.
Although men were the exclusive subjects of this study, Rose said the findings likely extend to women, as well, but need to be examined.
Researchers analyzed several biomechanical elements of subjects’ golf swings, including S-factor (tilt of the shoulders), O-factor (tilt of the hips) and X-factor the relative rotation of the hips to the shoulders, measured in degrees which is considered key to power generation. Previous research has shown that pro golfers who hit the ball far generally have a larger peak X-factor than their peers, but this study is more extensive in that it considers X-factor in relation to other rotational biomechanics of the golf swing over the full duration of the motion.
Among the 10 pros in this study, peak X-factor during a hard swing was highly consistent, varying just 7.4 percent from a mean of 56 degrees. Their club speeds at impact with the ball also were highly consistent, varying just 5.9 percent from a mean of 79 mph. In contrast, peak X-factor of the three least skilled amateurs the handicap-30 golfer and two novices fell below the professional range: 48, 46 and 46 degrees, respectively. These smaller X-factor angles correlated with slower club speeds at impact: 68, 66 and 56 mph, respectively.
In addition, the study describes S-factor, a term coined by the researchers, for the first time. S-factor is the angle or tilt of the leading shoulder relative to the level position. The researchers found that peak S-factor occurred right after impact and was highly consistent among the pros, varying just 8.4 percent from a mean of 48 degrees. The handicap-15 player and two novices had lower S-factors of 42, 42 and 33 degrees, respectively, while S-factors of the handicap-4 player and handicap-30 players both fell within the professional range.
The study also found that peak free moment the golfers’ turning force, or torque, measured using a special scale was highly consistent among the pros, varying only 6.8 percent from a mean.
The authors conclude that peak free moment, X-factor and S-factor “are highly consistent, highly correlated to [club head speed at impact], and appear essential to golf swing power generation among professional golfers.”
In addition, the researchers found overall biomechanical differences between the professionals and amateurs. “For example, the peak free moment of Novice #1 was reduced and delayed compared with the professionals,” the authors note. “His X-factor was excessive in early backswing, but insufficient in downswing compared with professionals. Novice #2 had a reduced X-factor throughout backswing and downswing.” Both of these players had lower club speeds at impact than the pros did.
“A precise understanding of optimal rotational biomechanics during the golf swing may guide swing modifications to help prevent or aid in the treatment of injury,” they wrote.
Conrad Ray, the Knowles Family Director of Men’s Golf at Stanford University and a co-author of the study, said the findings give scientific backing to the elements of golf-swing form that professionals have long understood are vital for generating power. The study also helps to clarify some unresolved questions about golf-swing biomechanics, Ray said. “One question that always comes from students is, ‘What starts the downswing?’” he said. “People have had different answers. Some would say the hands, or others would say the shoulders or the lower body. But the study confirms that rotation of the hips initiates the downswing. So that, to me, is an interesting finding.”
Ray, who as the men’s head golf coach led the Cardinal to five appearances in the NCAA championships and its eighth national title, in 2007, said the study validates the importance of X-factor in generating club speed. “All golfers want to know how to hit the ball longer, and this study support that speed is really a factor of relative body rotation,” he said.
There were some limitations to the study. Although club speed at impact is a common measure for determining power generation, the authors note that they were unable to measure the outcome of the swings, such as distance and accuracy; measurements were made in a lab, with players hitting the ball into a net. “Down the road, it would be interesting to correlate ball data to the rotational biomechanics,” Ray said.
The other Stanford co-authors of the study are Amy Ladd, MD, professor of orthopaedic surgery; Erin Butler, who recently earned her PhD in bioengineering; Betty Zhao, MS, a recent graduate student in mechanical engineering; and Andrew Rogers, a former undergraduate student in human biology.
The study was supported in part by the Medical Scholars Research Program at the School of Medicine and Media-X at Stanford University.
In the fall, Rose and her colleagues plan to begin offering a service for analyzing golf swing biomechanics through Stanford Hospital & Clinics Sports Medicine Clinic.
The Stanford University School of Medicine consistently ranks among the nation’s top medical schools, integrating research, medical education, patient care and community service. For more news about the school, please visit http://mednews.stanford.edu. The medical school is part of Stanford Medicine, which includes Stanford Hospital & Clinics and Lucile Packard Children’s Hospital. For information about all three, please visit http://stanfordmedicine.org/about/news.html.
Contact: John Sanford
jsanford@stanfordmed.org
650-723-8309
Stanford University Medical Center
Genetic evidence clears Ben Franklin of Tallow Invasion
July 28, 2011
Invasive tree afflicting Gulf Coast was not brought to US by Ben Franklin
The DNA evidence is in, and Ben Franklin didn’t do it.
Genetic tests on more than 1,000 Chinese tallow trees from the United States and China show the famed U.S. statesman did not import the tallow trees that are overrunning thousands of acres of U.S. coastal prairie from Florida to East Texas.
“It’s widely known that Franklin introduced tallow trees to the U.S. in the late 1700s,” said Rice University biologist Evan Siemann, co-author the new study in this month’s American Journal of Botany. “Franklin was living in London, and he had tallow seeds shipped to associates in Georgia.”
What Franklin couldn’t have known at the time was that tallow trees would overachieve in the New World. Today, the trees are classified as an invasive species. Like Asian carp in the Great Lakes and kudzu vines in the eastern U.S., the trees are spreading so fast that they’re destroying native habitats and causing economic damage.
Each tallow tree can produce up to a half million seeds per year. That fertility is one reason Franklin and others were interested in them; each seed is covered by a waxy, white tallow that can be processed to make soap, candles and edible oil.
Siemann, professor and chair of ecology and evolutionary biology at Rice, has spent more than 10 years compiling evidence on the differences between U.S. and Chinese tallow trees. For example, the insects that help keep tallow trees in check in Asia do not live in the U.S., and Siemann and his colleagues have found that the U.S. trees invest far less energy in producing chemicals that ward off insects. They’ve also found that U.S. trees grow about 30 percent faster than their Chinese kin.
“This raises some interesting scientific questions,” Siemann said. “Are tallow trees in the U.S. undergoing evolutionary selection? Did those original plants brought from China have the traits to be successful or did they change after they arrived? Does it matter where they came from in China, or would any tallow tree do just as well in the U.S.?”
In 2005, Siemann set out to gather genetic evidence that could help answer such questions. With funding from the National Science Foundation and the Department of Agriculture, he and study co-authors William Rogers, now at Texas A&M University, and Saara DeWalt, now at Clemson University, collected and froze leaves from more than 1,000 tallow trees at 51 sites in the U.S. and a dozen sites in China. The researchers conducted hundreds of genetic scans on the leaves, and they spent more than two years analyzing and correlating the results.
There were a few surprises. First, the tallow trees that are running amok in most of the U.S. aren’t from the batch that Franklin imported. The descendants of Franklin’s trees are confined to a few thousand square miles of coastal plain in northern Georgia and southern South Carolina. All other U.S. tallow trees the team sampled were descended from seeds brought to the U.S. by federal biologists around 1905.
“The genetic picture for Franklin’s trees is muddled; we may never know where they originated,” Siemann said. “But the genetic evidence for the other population — the one that’s problematic in the Gulf Coast — clearly points to it being descended from eastern China, probably in the area around Shanghai.”
In controlled tests in China, the researchers found the U.S. trees even grew and spread faster than their Chinese forebears, despite the lack of chemical defenses to ward off insects.
“They suffered twice the damage from insects that the natives did, but they grew so much faster that they still retained a competitive edge,” Siemann said.
“In some ways, this raises even more questions, but it clearly shows that if you are going to explore control methods for an invasive species, you to need to use appropriate genetic material to make certain your tests are valid.”
Siemann said that with many new species of plants and animals still being introduced from foreign environments into the U.S. each year, it is vitally important for scientists to better understand the circumstances that cause introduced species to cross the line and become dangerous invasive pests.
Contact: Jade Boyd
jadeboyd@rice.edu
713-348-6778
Rice University