Archives: 2007
The University of Illinois at Chicago is in possession of an MRI machine unlike any other. Featuring a 80cm bore size and a magnetic field of 9.4 Tesla, this unit is significantly more powerful than anything currently on the market.
The world’s most powerful medical magnetic resonance imaging machine, the 9.4 Tesla at the University of Illinois at Chicago, has successfully completed safety trials and may soon offer physicians a real-time view of biological processes in the human brain.
The safety study was published in the November Journal of Magnetic Resonance Imaging in an issue focused on MRI safety.
Researchers and physicians hope that the 9.4T will usher in a new era of brain imaging in which they will be able to observe metabolic processes and customize health care.
Oncologists, for example, may one day be able to tailor radiation therapy based on a brain tumor’s real-time response to treatment. Currently, physicians often must wait weeks to see if a tumor is shrinking in response to therapy. With the 9.4T, it will be possible to see if individual cells within the tumor are dying long before the tumor has begun to shrink.
The 9.4T magnet has a field strength more than three times that of state-of-the-art clinical units. UIC’s 9.4T is the first such device large enough to scan the head and visualize the human brain.
“Because the more powerful magnet allows us to visualize different types of molecules, we are seeing activity in the brain along a completely different dimension,” said Dr. Keith Thulborn, director of UIC’s Center for Magnetic Resonance Research.
Current MRI visualizes water molecules to track biochemical processes. By visualizing the sodium ions involved in those processes instead, the 9.4T permits researchers to directly follow one of the most important energy-consuming processes in the cellular machinery in the brain.
Press release: World’s Most Powerful MRI Ready to Scan Human Brain…
Medtronic, Inc. has filed a Pre-Market Approval (PMA) application with the FDA for the company’s new Talent™ Abdominal Stent Graft System. This endovascular device is similarly designed, and is in the same family, with previously reported Talent™ Thoracic Stent Graft System for descending thoracic aneurysms.
The Talent Abdominal Stent Graft is designed to offer broad patient applicability and ease of use, and a history of established clinical performance with more than 40,000 implants worldwide. The results of the clinical trial demonstrated that the study met its primary safety endpoint of superiority in freedom from major adverse events at 30 days, and the aneurysm-related mortality rate at 12 months was 1.8 percent. Although patients receiving the Talent Abdominal Stent Graft were older and had a higher baseline rate of co-morbidities, they experienced lower rates of death, myocardial infarction, respiratory failure, paraplegia, and blood loss compared with subjects treated with open surgery at 12 months. There were no aneurysm ruptures and no conversions to open surgery in the Talent Abdominal Stent Graft group up to 12 months after device implantation.
“As part of the FDA’s modular review process, we have submitted the final module — a comprehensive clinical data set for the Talent Abdominal Stent Graft PMA application,” said Katie Szyman, vice president and general manager of the Endovascular Innovations business at Medtronic. “The Talent Abdominal System will expand treatment options for patients with abdominal aortic aneurysms and provide a strong complement to our market-leading AneuRx® AAAdvantage Stent Graft.”
Press release: Medtronic Files PMA Application for FDA Approval of Talent Abdominal Stent Graft System …
Rarely does a medical device case find itself at the Supreme Court of the US. Yesterday, Medtronic insisted that if the FDA approves a device for safety and efficacy, then it should be immune to cases that challenge its design safety.
From the Financial Times:
The case before the court, Riegel v Medtronic , could have big implications for makers of medical devices and possibly other products. The issue before the court was: can patients bring state product liability lawsuits when the federal Food and Drug Administration has authorised a medical device for sale under its most rigorous approval process?
The case is one of several this term in which the justices confront an issue of big importance to the business community: when do federal regulations pre-empt often tougher state personal injury laws?
Read the rest at Financial Times…
The Salk Institute for Biological Sciences is reporting on developing a technique for transplanting human hepatocyte cells into the livers of lab mice, and provide a new way to test treatments for liver disease.
Cells cultured in the lab are like a fish out of water. Often, their behavior does not reflect their biological function within an entire organ or organism, which, for example, turns studying human liver cells into a big challenge.
One way to get around the altered properties of the stranded cells is to populate mouse livers with human hepatocytes in the hope of creating a natural environment, which is exactly what researchers at the Salk Institute for Biological Studies did. They developed a simple system that allows them to transplant human hepatocytes into immunodeficient mice, which can now be used to test how drugs affect the liver…
In fact, that’s the underlying principle of the Salk researchers’ new chimeric mouse. It is based on a murine model for hereditary tyrosinaemia type I, developed by researchers at Oregon Healthy & Science University. An enzymatic defect in the tyrosine catabolism results in a toxic accumulation of byproducts within hepatocytes unless the mice are treated with a drug called NBTC.
Withdrawing the drug allows to selectively expand hepatocytes that do not have this defect, such as transplanted human hepatocytes. Within three months of transplantation, up to 20 percent of the mouse liver is repopulated by human hepatocytes. But what’s more, the transplanted cells keep producing a foreign protein slipped inside with the help of a lentiviral vector, the kind usually used for gene therapy. “We are very excited about that aspect since very often cells shut off the production of proteins introduced as part of gene therapy,” says Verma [Inder Verma, Ph.D., a professor in the Laboratory of Genetics].
Image: Transplanted human liver cells (shown in brown) take hold in the mouse liver and repopulated the host organ over time. The images above show cross sections of mouse liver one month (top), two months (middle), and three months (bottom) after the injection of human hepatocytes.
Courtesy of Dr. Karl-Dimiter Bissig, Salk Institute for Biological Studies
Press release: New chimeric mouse model for human liver diseases, drug testing …
A charity group called Segs4Vets is giving away dozens of Segways for injured soldiers that are undergoing therapy and have trouble walking. Many can stand, but walking is more difficult, and for them a Segway is proving to be a much better solution than a wheelchair.
Although not approved as a medical device, disabled veterans report that the Segways give them greater mobility. Therapists say they could be part of a future movement for the industry because they force soldiers to stand longer, which helps them is getting used to their prosthetic limbs.
“We’re in the walking business,” says Mark Heniser, a physical therapist at Brooke Army Medical Center in San Antonio. “We are giving these guys … knees with microprocessors that cost tens of thousands of dollars. We want them to use them. This will help them walk more efficiently.”
Segs4Vets was created by St. Louis businessman Jerry Kerr, who suffered a spinal cord injury nine years ago. Kerr, a home builder and real estate developer, shattered a vertebra in his neck in a diving accident at his lake house in 1998. After years of therapy, Kerr regained the ability to stand and has some control of his hands, but can hardly walk.
Kerr, 53, was among the first to buy a battery-operated Segway, shortly after the device was introduced in 2001. He used it around his house for everyday getting around and for trips, such as when he toured Yosemite National Park. He liked being able to talk to people eye to eye despite his injury.
And something else happened.
“The more I used it, the stronger I got,” Kerr says. “All those balancing muscles that disappeared started coming back.”
Hearing about soldiers and Marines who lost limbs fighting in Iraq and Afghanistan got Kerr thinking about how he could help. He wanted to honor their sacrifice and see if they also could benefit from Segways.
More from USA Today…
Segs4Vets Homepage…
As was promised, Digital Angel Corp., VeriChip Corp., and RECEPTORS LLC announced yesterday the release of a white paper entitled “Development of an Implantable Glucose Sensor” that discusses development plans for a self-contained implantable RFID glucose-sensing microchip.
Upon completion, the in vivo glucose-sensing microchip will be the first device able to measure glucose levels in the human body and be read with an external reader.
You can review the original document here: White paper (.pdf)…
Press release: Digital Angel Corporation, VeriChip Corporation and RECEPTORS LLC Publish White Paper for Self-Contained Implantable RFID Glucose-Sensing Microchip …
Sermo.com, a social network for doctors, has quietly changed its registration requirements to better verify the registrants as real doctors. Now, in addition to providing personal, but publicly available regulatory information such as DEA and state license numbers, a physician is expected either to fax to Sermo a copy of current state medical license or copy of hospital or practice ID, or to provide a phone number and name of hospital for Sermo team to call to confirm one’s identity.
We are glad that Sermo has addressed criticisms leveled against it and other similar networks. Assuring that all members participating in discussions are real doctors is important not just for networks themselves (and their members), but also for public health. For example, since Sermo.com is trying to forge a relationship with the FDA, it is imperative on its management team to re-register all of its current members, as there have been reports of trolls infiltrating its website. We don’t know how many trolls exist on these doctor networks, but what we know is that they are there. Anything short of a full new round of registration of the existing members can potentially endanger the public, as trolls (if planted by pharma and device companies, as well as single individuals with evil intent), can influence doctors on the site, and the FDA’s regulatory process in general.
Spokeswoman for the FDA has refused to comment for this story. Medgadget has not contacted Sermo since we’ve been designated blog non grata by the network’s management before.
More: Medgadget’s Guide to Hacking into Social Networks for Doctors …; Confirmed: Sermo Is Not for Physicians Only; New Important Questions Raised …; Sermo’s $9M Weak Security Model …; A Note and a Follow Up On Sermo …
Researchers at the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Dresden (Fraunhofer-Institut für Werkzeugmaschinen und Umformtechnik IWU) developed a variable frequency ultrasound system that might have potential in the treatment of chronic wounds:
Unlike the ultrasound used in prenatal examinations, which operates at frequencies of several hundred kilohertz, the frequencies used here are measured in tens of kilohertz. Devices operating at fixed frequencies are already available. But what effect does the treatment have on the patient’s circulation? The only empirical data that exists at present is based on patient surveys.
Researchers at the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Dresden teamed up with colleagues from IMM Ingenieurbüro Mittweida and Smart Material GmbH Dresden to carry out a systematic study of this method. How often, for how long, and at what frequencies do wounds have to be treated to prepare them optimally for transplantation? “We have developed a device that permits the frequency of the ultrasound waves to be varied between 20 and 120 kilohertz, and also has an output regulator,” says IWU team leader Dr. Gunther Naumann. “To stimulate the blood flow in the deeper epidermal layers, we need a lower frequency than that required to clean the wound in the subcutaneous zone.” Another unique feature of the new ultrasound device is that it is equipped with a measuring system that directs light into the wound using special probes. The red region of the color spectrum of the reflected light indicates the concentration of oxygen in the blood – which in turn reveals how efficiently the tissue is being irrigated. “Our observations have shown that the oxygen concentration continues to rise for 30 minutes after treatment. But we need to conduct further investigations to determine whether a sustained higher level can be reached after repeated treatment,” Naumann reports. A prototype of the new device has been installed for use in clinical trials in the Department of Dermatology and Allergology at the academic teaching hospital in Dresden-Friedrichstadt. Ten patients have been treated so far. The study is to be continued in 2008.
