New bone: An x-ray image of a patient who had a leg lengthened using the new
surgical method. This image was taken after six months, showing a healed bone.
Credit: Ulf Knothe
A simple method uses stem cells from bone tissue to repair serious injuries quickly and cheaply.
MIT Technology Review, March 10, 2010, by Brittany Sauser — A new surgical procedure can repair severe bone injuries and defects more quickly and simply than current methods, which include bone-grafting operations and lengthening procedures that involve inserting pins through the skin to pull bones together.
The new technique makes use of a thin tissue called the periosteum, which lines the outer surface of all bones and contains stem cells that develop into bone to repair damage. To repair major bone breaks, or repair serious defects, the researchers use the periosteum as a sleeve placed around a missing section of bone to encourage bone regrowth. For cases where there is not enough periosteum, the researchers have developed an artificial membrane as a substitute.
Melissa Knothe Tate, a professor of biomedical engineering at Case Western Reserve University in Cleveland, and her husband, Ulf Knothe, an orthopedic surgeon at the Cleveland Clinic, have successfully tested their method on a wheelchair-bound patient who needed surgery to lengthen one of her legs. They’ve also successfully tested it on sheep. The researchers presented their work yesterday at the Orthopedic Research Society meeting in New Orleans.
In the new procedure, carried out on the wheelchair patient, the researchers made a small vertical incision in the periosteum near to where a large piece of bone was missing after the leg had been lengthened. They then peeled the periosteum back, so that it remained attached to the blood vessels on the outside, and cut away a piece of bone beneath, which was then used to plug the large gap in the leg bone. The periosteum was sutured closed, forming a sleeve around the section from which the bone was removed. The gap was repaired by the transplanted segment of bone while cells from the sutured periosteum infiltrated the space below it and turned into new bone. The patient saw new bone growth one month after surgery. Knothe Tate says that such a defect would normally not heal without more serious surgery.
One of the most common methods for treating a severe bone injury is to take bone from a non-weight-bearing area like the hip and graft it onto the injured site, but that can leave the site the bone was taken from at risk of a fracture. Jennifer Elisseeff, a biomedical engineer at Johns Hopkins University, says very little can be done to fix large gaps in bone, but adds that the new technique “will have a significant effect for healing fractures.”
Norman Marcus, an orthopedic surgeon at the Virginia Cartilage Institute, in Springfield, VA, says artificial treatments fall into two categories: structural and growth-related. Structural products, typically called bone fillers, can be made of items like coral and calcium phosphate. Growth-related products, which are usually in the form of powders and gels, are used to stimulate bone growth. While the growth promoters are more effective, they are expensive, says Marcus.
The researchers have also created an artificial periosteum sleeve, which they tested in sheep, for bone injuries where there is not enough tissue available. The artificial membrane was seeded with collagen; a mixture of collagen and periosteal cells taken from a particular sheep; or pieces of periosteum from the patient’s surrounding bone. The researchers wrapped the sleeve around the injured area and sewed it on like a patch. They found that the sheep given the periosteum alone experienced the fastest repair, with new bone growth two to three weeks after surgery.
The work “combines tissue engineering approaches with surgical intervention and leverages the natural ability for repair,” says Elisseeff.
One problem is that stem cells can differentiate into different things like tendons, cartilage, or bone, says Marcus. The researchers showed that the stem cells in the periosteum were coaxed into becoming bone by mechanical stress. For instance, in the sheep experiments, the mechanical cues happen naturally when the sheep shift their weight.
“There are lots of experimental techniques but few clinical methods, and if this has been successful in patients, that is where the real breakthrough will be,” says Farshid Guilak, a professor of orthopedic surgery and director of the Orthopaedic Bioengineering Laboratory at Duke University Medical Center.
“This is very important progress,” adds Yunzhi Yang, an assistant professor at Houston Biomaterials Research Center at the University of Texas Health Science Center in Houston.
Knothe Tate says the plan is to license the technology to companies by the end of the year, and says there are a couple of “major players” interested. “We want to provide a cheap alternative that can be widely used in the field,” she says
The-Scientist.com, March 10, 2010, by Bob Grant — Two hundred kilometers north of Hobart, Tasmania, on a late September afternoon in 2001, two men broke into the rural home of 71-year-old Fay Olson. The intruders—armed with sticks and wearing black hoods—ransacked Olson’s home, forced her to open a safe, stuffed AU$550 into a pillow sack, and fled into the bush surrounding the house. They left Olson tied up with a belt cinched around her ankles. The pair made off with their loot scot-free, but one of the perpetrators inadvertently left something behind that would spell his undoing 8 years later: a leech, swollen with his DNA-filled blood.
Tasmanian investigators found little in the way of evidence that could tie the criminals to the crime, but one of the officers on the scene noticed a bloated leech wriggling next to the pilfered safe. He collected the parasite—likely Philaemon grandis, endemic to Tasmania—as the lone piece of evidence that might help catch the men.
“[The leech] had obviously just fed,” says Michael Johnston, the lead investigator on the case. “It was fully engorged.” Johnston and his fellow officers noted that neither they nor Olson had been bitten by the leech, so reasoned that it had to have dropped off one of the criminals.
They kept the leech, killed it, and smeared some of its final blood meal onto a special card treated with DNA preservatives—standard police procedure. The blood sample was sent to Forensic Science Service Tasmania (FSST), the lab that handles DNA profiling and forensic chemistry for the state’s police. Pam Scott, who was a case worker then but is now the manager of forensic biology at FSST, remembers when the leech sample came into the lab. “It was certainly something out of the blue and a very good piece of lateral thinking by the investigators at the scene,” she says. “We did get a [DNA] profile from it.”
That forensic investigators got a viable sample of human blood from the leech was not that surprising, according to Mark Siddall, director of the American Museum of Natural History’s leech lab in New York City. Leeches typically consume about 6 times their own body weight in blood, and the quick-thinking Tasmanian police preserved the blood soon after finding the leech. “My guess is that as long as the leech isn’t allowed to rot, then it would probably behave almost as any other piece of forensic material,” notes Siddall, who wasn’t involved with the case. Siddall adds that using human-specific primers to amplify the DNA from the leech’s blood meal would prevent the amplification of leech DNA, which may interfere with analysis.
Sadly, the DNA isolated from the human blood in the leech didn’t match any other genetic profiles on the Tasmanian DNA Database, so the case went cold.
Then last year, Tasmanian police caught a break in the case. Peter Cannon, a 54-year-old Tasmanian man, was picked up on drug charges and submitted a blood sample from which police pulled a DNA profile. When investigators entered Cannon’s DNA data into the database, a match came back—the blood inside the leech left in Olson’s looted home bore the same profile as Cannon’s. Confronted with this, Cannon pled guilty to aggravated armed robbery and is serving out his 2-year sentence in a Tasmanian prison.
“This would appear to be the first and only time anywhere in the world that a leech served as a source of [incriminating] DNA.” says Johnston, now acting commissioner of Tasmania’s northern district.
The case of Cannon and the Tasmanian leech that led to his conviction demonstrates that the potential sources of incriminating DNA evidence may be limitless. “Maybe there’re other sources that aren’t leaping out at us currently,” says Scott. And could the leech that caught Cannon boost the reputation of its brethren still in the swamps?
“If anything, it does something for the reputation of Tasmanian forensics, that they had the presence of mind to do this,” Siddall says.
In a pilot project, technology reduced doctor’s visits for patients with chronic illness, but will this work on a broader scale?
MIT Technology Review, March 10, 2010, by Emily Singer — Connecting patients and their physicians through the internet might help cut down on office visits, according to results of a pilot project announced today. More than 250 patients with chronic diseases, namely diabetes, heart failure, and hypertension, participated in the study, tracking their health at home with heart rate monitors, glucometers, scales, pedometers or blood pressure monitors. Data from those devices was then uploaded to the patient’s HealthVault record, a personal medical record system developed by Microsoft. That data was in turn connected to the electronic medical records used by the Cleveland Clinic, allowing doctors to monitor their patients remotely.
According to a the following press release from the Cleveland Clinic:
“The project found a significant change in the average number of days between physician office visits for patients. Diabetic and hypertensive patients were able to make doctor’s office visits less often, increasing the number of days between appointments by 71 percent and 26 percent respectively, indicating that patients had better control of their conditions. Heart failure patients, however, visited their doctors more often, decreasing the number of days between visits by 27 percent, indicating that patients were advised to see their healthcare provider in a more timely manner.
… “Making it easier for patients to more actively engage in their ongoing health and wellness is a necessary step in trying to manage the increasing onset of chronic disease worldwide and the costs associated with this alarming trend,” said Peter Neupert, corporate vice president, Microsoft Health Solutions Group. “The results of this pilot are promising and demonstrate how cost-effective and flexible technology solutions can support patients in better monitoring their chronic conditions from where they live and work.”
Any option for reducing health care costs is, at the moment, a hot topic. But how successful will this type of program be on a broader scale? My doctor belongs to a tech-savvy medical practice. (One of the first, in fact, to adopt electronic medical records.) And despite a handy online system that allows me to check my test results and contact my physicians, I can’t even get him to answer emails. So I have a hard time imagining him poring over reams of heart rate and blood pressure data.
The question is not just whether the system reduced office visits, but whether it helped cut down physician’s time expenditure per patient, either by helping patients stick to their treatment plans, or by transferring some of the evaluation process to less-skilled personnel or even a computer program. It’s unclear from the information released whether patients better monitored their own health, which perhaps made them more compliant with medication regimens, reducing the need to see the doctor. Or whether a nurse or other health care practitioner was able to monitor the medical record, only alerting the doctor of concerning data.
US President Barack Obama’s 2009 executive order to allow the federal funding of research using new human embryonic stem cell (hESC) lines may become law
The-Scientist.com, March 10, 2010, by Jef Akst — Yesterday (March 9), on the one-year anniversary of Obama’s announcement, members of Congress Diana DeGette of Colorado and Mike Castle of Delaware reintroduced the Stem Cell Research Advancement Act to “ensure a lasting ethical framework” for such research. DeGette and Castle were the lead sponsors of the bill when it was introduced during the tenure of former President George W. Bush, who vetoed it twice.
The legislation would codify Obama’s executive order, which overturned the limitations implemented by Bush, and made it possible for scientists to use federal funds to study hESCs derived after August 9, 2001. So far, the National Institutes of Health (NIH) have approved a total of 43 lines, more than double the lines available for distribution during the Bush administration.
The new bill builds on the NIH guidelines introduced last summer for approving hESC lines for federal fudning, and requires that the NIH review and update the guidelines at least every three years, as well as submit a biennial report to Congress on the research.
“Congress must still enact legislation so that both scientists and individuals who stand to benefit from the promise of this research will have some stability backing their quest for life-changing cures,” DeGette said in a statement.…….read the statement here…………. http://www.castle.house.gov/News/DocumentSingle.aspx?DocumentID=175218