Posted on February 28th, 2014 by Bob Nellis
We want to pass on some published Mayo Clinic research as reflected in the media this week. This one, from the Annals of Thoracic Surgery is especially interesting and useful to both physicians and patients alike.
HealthDay, Getting Teeth Pulled Before Heart Surgery May Pose Serious Risks by Randy Dotinga…In a small, retrospective study, Mayo Clinic researchers found that 8 percent of heart patients who did not wait to have teeth pulled suffered major adverse health outcomes, such as a heart attack, stroke, kidney failure or death. "Guidelines from the American College of Cardiology and American Heart Association label dental extraction as a minor procedure, with the risk of death or non-fatal heart attack estimated to be less than 1 percent," study co-author Dr. Mark Smith said in a statement. Additional coverage: KSAZ Ariz., US News & World Report, FOX News, MedicineNet.com, Forbes.com, WMCTV.com, Fox5Vegas.com, 19ActionNews.com,WDAM.com, HHS HealthFinder.gov,
Posted on January 2nd, 2014 by Admin
A Mayo Clinic researcher, along with collaborators from Harvard Medical School, developed a method to first identify a breast-cancer-promoting gene and then specifically target this gene with a nanoparticle-based, injectable therapy that reverses breast cancer in mice. The results, published this week in Science Translational Medicine, may provide a first step in developing a new non-surgical treatment option for patients diagnosed with early-stage breast cancer.
“Precancerous cells are at a tipping point, in which they could become full-blown cancer or not," says Mayo Clinic pharmacologist Hu Li, Ph.D., a co-first author on the study. "Our results show that, if we know the right target genes, it is possible to tip the balance in favor of a more normal cell state, preventing cancer progression, and improving survival outcomes.”
Identifying the Enemy
In order to identify the most-significant genes that were turning normal breast cells into tumor cells, the researchers developed a computational approach to identify cancer-related changes in regulatory genes which, in turn, control many other genes. In theory, targeting such regulatory genes could have a dramatic effect, based on all of the downstream genes which would also be affected. The team zeroed in on a specific regulatory gene, HoxA1, as a driver of breast cancer in mice with a high rate of hereditary breast tumors.
A Nanoparticle Approach
To see if HoxA1 could be targeted to prevent further tumor development in these mice, the team decided to down-regulate HoxA1 within the breast tissue, specifically in the cells where the tumor develops.
To accomplish this, they used tiny, fat-based nanoparticles, which were coupled to molecules designed to specifically down-regulate HoxA1, and may be injected into the body. Hoping to reduce toxicity, they decided to inject these nanoparticles directly into the breast ducts, specifically where the tumors form, rather than systemically, as others have tried in the past.
The result: The researchers discovered that mice developed dramatically fewer tumors when treated with this novel therapy. They also found that targeted depletion of HoxA1 appeared to reverse tumor characteristics, effectively tipping the cellular balance back to a normal cell state.
In the same way that HoxA1 was identified, the researchers say it may be possible to advance the technology to the point where doctors are able to identify the best therapeutic gene targets specific to an individual patient’s tumor, allowing for the design of tumor-specific and patient-specific therapeutic strategies.
The research was supported by the Department of Defense, SysCODE (Systems-based Consortium for Organ Design & Engineering), the National Institutes of Health, Susan G. Komen Foundation, the Wyss Institute at Harvad, and Mayo Clinic.
Study collaborators include Amy Brock, Ph.D., The University of Texas at Austin; Silva Krause, Ph.D., Michael S. Goldberg, Ph.D., Marek Kowalski, and Donald E. Ingber, M.D., Ph.D., all of Harvard University; James J. Collins, Ph.D., of Howard Hughes Medical Institute, Boston University, and Harvard University.
Dr. Hu Li, et al. Silencing HoxA1 by intraductal injection of siRNA lipidoid nanoparticles prevents mammary tumor progression in mice.
-- by Debra Evans
Posted on December 18th, 2013 by Admin
From Mayo Clinic's Discovery's Edge magazine
Many prostate cancer survivors live in fear of being told that their cancer has returned. It’s even scarier to be told that the doctor knows the cancer is there because of rising PSA levels, but that he can’t find it. Doctors and patients alike know that early detection of the recurrent cancer is critical to the patient’s chance of beating it a second time.
The problem, however, is locating it.
A Mayo Clinic research team has developed a new imaging technique that can often find the recurrent disease months, if not years, earlier than other imaging techniques. Prostate cancer uses choline, a B-complex vitamin, as a building block. So when a minute amount of radioactively-labeled choline (choline C-11) is injected into a patient, it is quickly taken up by the cancer — like a fish rising to the bait.
The prostate cancer then emits radiation, allowing doctors to pinpoint its location. A positron emission tomography (PET) scanner is “able to tell where in the body this radiation is being emitted,” explains Mayo Clinic radiologist Val Lowe, M.D..
Choline C-11 isn’t toxic, and the radioactive element is so minimal, it’s really not much of a pharmacologic safety issue, explains Dr. Lowe. “If you take a grain of sugar and divide it into 100 pieces, one of those pieces is enough to do a PET scan.”
As well as being safe, the PET scan takes little time. Once the radioactive element is added to the choline C-11, it has a very short shelf-life. The half-life of choline C-11 is only 20 minutes, meaning it loses half of its radioactivity every 20 minutes. Because the radioactivity is the imaging agent that allows the PET scanner to see the cancer, the agent must be used shortly after it’s made. It cannot be stored and shipped. It essentially must be manufactured on-site.
All told, it takes about 45 minutes to make choline C-11, and the scan itself takes only about 20 minutes. The results are analyzed and a report is typically ready half an hour after the scan is completed.
“For the first time ever, we will have a clear blueprint of where the patient stands, at a far earlier course in treatment failure,” says Eugene Kwon, M.D., a Mayo Clinic urologist. “It has basically ripped the curtain off the Wizard of Oz.”
At this time, Mayo Clinic is the only health care provider in the country authorized to do this test. But when filing with the FDA, Mayo Clinic waived all exclusivity. It wanted other sites in the country to be able to manufacture and use the drug to better serve their own patients.
Posted on December 9th, 2013 by Admin
The blogs feature commentary from Mayo Clinic experts about most recent news and advances within each disease, specifically:
The content produced on these blogs is meant to spur discussion and our contributors look forward to answering any questions left in the comment section of blog posts or YouTube videos.
We also encourage our readers to use the comment section of posts to propose any topics they would like to see discussed in future posts.
Thanks for your continued interest and we look forward to expanding our collection of content focused on these conditions.
Posted on December 2nd, 2013 by Admin
From Mayo Clinic's Discovery's Edge magazine
Reducing radiation exposure from CT scans has become one of the primary goals of Mayo Clinic’s CT Clinical Innovation Center. Dr. Cynthia McCollough and her colleagues are doing the Radiation Limbo: How low can they go without sacrificing image quality.
Dr. McCollough is continually looking for ways to lower radiation exposures while maintaining the needed quality. A critical step in that process includes better defining what level of image quality is needed.
“We don’t always need pretty pictures,” says Dr. McCollough. “We only need pictures that clearly show the disease or injury. For some conditions, a really low exposure of radiation can be used.”
To reduce the amount of radiation patients are exposed to, the CT Clinical Innovation Center takes several routes. “The most basic, low-tech thing we can do is to ‘right-size’ the dose,” says Dr. McCollough.
Mayo Clinic has developed a computerized set of electronic protocols that are centrally managed. If an adjustment is made to a protocol, the correct, new information is instantly available at all 25 CT scanners on the Mayo Clinic campus in Rochester, Minn., as well as at all Mayo Clinic Health System sites, and the Mayo practices in Florida and Arizona.
Much like the automatic exposure feature on a camera, CT scanners can now automatically adjust the radiation exposure that the patient receives based on the type of exam and the size of the patient. “Everything we're doing with dose reduction is to make sure patients get the exams they need at the lowest radiation doses,” says Dr. McCollough.
One area where use of medical radiation has increased dramatically in recent years is in cardiology. It is also one of the areas that has seen significant decreases in the levels of radiation exposure. Dr. Charanjit Rihal, a cardiologist at Mayo Clinic, says the results have been encouraging. “We reduced the amount of radiation by at least 40 percent, and in some cases, by as much as 70 percent.”
Another of Dr. McCollough’s colleagues, Dr. Joel Fletcher a radiologist and the medical director of the CT Clinical Innovation Center, worked with the pediatric oncology group to lower the radiation dose for follow-up CT scans for children diagnosed with cancer who had completed treatment.
“We just kept turning down the dose until finally it was down to the lowest setting the scanner would run at,” says Dr. McCollough. With each setting, a pediatric radiologist would look at the scan to ensure that the image was still clear. “We try to do the limbo: you know, ‘How low can you go?’”
With education, new technology, and collaboration between physicists, radiologists, and other physicians, Mayo Clinic is answering that question.
Posted on November 25th, 2013 by Admin
Pioneers of Kidney Transplantation at Mayo Clinic
The first transplant of a kidney took place in Saint Marys Hospital on Nov. 25, 1963. Surgeons George A. Hallenbeck, M.D., and James DeWeerd, M.D., headed a medical team that performed the first transplant, placing a kidney in a female patient. The patient’s half-sister was the donor. Mayo’s operation reflected a common theme in the early development of transplant medicine. The donor providing the kidney was a close relative of the recipient. That was important at the time to minimize rejection of the organ by the recipient’s body.
George Hallenbeck, M.D., had acquired a deep knowledge of physiology and an interest in experimental surgeries before he stood at that operating table. Dr. Hallenbeck also designed Mayo’s initial kidney transplant program. Once it began, he was named to direct Mayo’s Section of Tissue and Organ Transplantation. He subsequently headed the surgical teams for more than 40 kidney transplants.
Dr. Hallenbeck was among Mayo’s most accomplished surgeons and researchers. Besides a medical degree, he held a doctorate in physiology with specialty work in gastric secretions. During World War II, Dr. Hallenbeck worked on the physiology of acceleration for Mayo, and served on the U.S. Army’s development team for the famed “G-suit.” It was created to protect fighter pilots from blackouts under extreme flight conditions.
Frank C. Mann, M.D., and his Mayo Clinic laboratory were probing the science of kidney transplants in the 1920s, decades before surgeons performed the first patient operations. A surgical resident working with the laboratory drew several insights from the failure of transplanted kidneys. Carl S. Williamson, M.D., was among the early scientists to recognize a “blood-borne” factor that needed to be overcome to prevent rejections. In later remarks, Dr. Mann observed: “The successful transplantation of a healthy organ for a diseased one awaits the discovery of those biologic factors which prevent the survival of tissues of one individual when transplanted into the body of another individual.” Dr. Mann and his associates also pioneered surgical techniques for kidneys. Among them was the method developed by Dr. Williamson, which was used in the first kidney transplants on humans. Dr. Mann came to Mayo Clinic in 1914 as director of experimental medicine and retired in 1952.
Posted on November 25th, 2013 by Admin
[Editor's note: We recently looked at benchmarks in kidney transplant history. Today more on the kidney and why it's so important.]
The Kidney’s Critical Role
The kidney’s well-being is essential for the rest of the body. It acts as the main filtering system for wastes and the major factor in excreting them from the body.
With each heartbeat, about one-fifth of the blood supply floods into the kidney. The organ contains enormous numbers of “nephrons’’ containing microscopic tubes. They are sized precisely to strain undesirable waste chemicals from the blood stream.
Each human has two kidneys and easily can survive with a single one. But various genetic diseases, infections or poisons can destroy the nephrons in both kidneys.
Once the kidneys are incapacitated, the damage is life- threatening. Doctors today can offer two main treatments to patients with terminal renal disease – transplantation or dialysis.
Although individual cases differ, Mayo Clinic doctors tend to favor transplants because of better and longer-lasting results. Kidney transplants can be performed at almost any age.
Medical Advances that Made a Difference Over 50 Years
Kidney transplant surgeries are possible due to ongoing, significant biomedical advances. Perhaps the single most important advance involves preventing the recipient’s immune system from rejecting the donated kidney.
• Prednisone – a steroid used in the early days of transplantation and still used today
• Azathioprine – introduced in 1968
• Cyclosporine – approved in 1983 and in wide use today
Doctors today can “precondition” the recipient’s blood to remove antibodies that would trigger rejection of a donated kidney.
Antibiotics, antimicrobial and related medicines – These drugs help ward off infections in patients with weakened immune systems.
Laparoscopy has greatly reduced the size of incisions and shortened recovery times for kidney donors. Mayo surgeons first started using the technique in 1999. It’s sometimes called “bellybutton surgery.” The surgeon inserts a long instrument with a camera through narrow holes in the donor’s abdomen, snips away a healthy kidney and recovers it through another small opening. Previously, the operation involved a much larger incision on one side of the donor’s back.
Posted on November 22nd, 2013 by Admin
A Mayo Clinic laboratory study has revealed a possible mechanism to stop recurrence of cancer in mice. The approach, involving screening and a second-line treatment, prevented cancer from coming back in most of the mice in the study in which recurrence would have happened. The findings appear in Nature Medicine.
It’s been long known that cancer tumors change their appearance or phenotype, as well as their genomic characteristics, to avoid the natural immune response from the host body. A collaborative international team led by Richard Vile, Ph.D., Mayo Clinic molecular medicine researcher, attempted to detect or anticipate that shift and then initiate a “pre-emptive strike” before the tumor fully evolves, thus preventing a relapse.
The researchers say the findings may lead to new methods of early cancer detection and “appropriately timed, highly targeted treatment of tumor recurrence irrespective of tumor type or initial treatment.”
The research was supported by the Richard M. Schulze Family Foundation, Mayo Clinic, Cancer Research UK, the National Institutes of Health, and a grant from Terry and Judith Paul.
Other collaborators in the research are: Timothy Kottke, Nicolas Boisgerault, Ph.D., Rosa Maria Diaz Ph.D, Diana Rommelfanger-Konkol Ph.D, Jose Pulido, M.D., Jill Thompson, Debabrata Mukhopadhyay, Ph.D., of Mayo Clinic; Oliver Donnelly, M.D., Alan Melcher, M.D. Ph.D., and Peter Selby, M.D. Ph.D., of Cancer Research UK; Roger Kaspar, Ph.D., TransDerm, Santa Cruz; Matt Coffey, Ph.D., Oncolytics Biotech, Calgary; Hardev Pandha, M.D. Ph.D., University of Surrey; Kevin Harrington, M.D. Ph.D., The Institute of Cancer Research, London.
Posted on November 12th, 2013 by Admin
From Mayo Clinic's Discovery's Edge magazine
Imagine the distress of waiting in a stalled checkout line, the bathrooms located at the back of the store, when your bowels begin to rumble and you have the uncontrollable urge to go. For those with fecal incontinence, panic ensues with the very thought of being caught unprepared at moments like these.
Mayo Clinic gastroenterologist Dr. Adil Bharucha has heard too many stories from his patients, mainly women over 40, about the panic created by the inability to control bowel movements, causing stool to leak unexpectedly from the rectum. In the worst cases, fecal incontinence can lead to a complete loss of bowel control.
Since one in 10 women experiences this embarrassing condition and since the prevalence increases with age, fecal incontinence was once thought to be the results of trauma during childbirth. Dr. Bharucha discovered, however, that rectal urgency and diarrhea, rather than obstetric trauma, are the main risk factors for fecal incontinence among women
He also knew he needed better diagnostic tools to identify and assess anorectal function if he hoped to help women suffering from fecal incontinence. With that goal, he set about building an extensive network of collaborators both within Mayo Clinic and externally to develop new diagnostic tests and devices. This work has led him to collaborating widely across the institution to improve care for the patient.
The work of Dr. Bharucha and his research colleagues has earned international acclaim for Mayo Clinic's gastrointestinal motility clinic, the first center nationwide to introduce high resolution anorectal manometry into clinical practice; and to develop normal values and a system with which to classify patients with defecatory disorders, including fecal incontinence. It now offers a panel of tests to assess rectal stiffness, sphincter strength and urgency. This comprehensive approach provides an array of sophisticated diagnostic tools to help researchers zero in on the cause for fecal incontinence in each patient.
"Most of my collaborators had never considered working in my field," Dr. Bharucha says. "I am very grateful for their enthusiasm and expertise once they understood how common and distressing these disorders are. People say that the beauty of collaborating is that you work with smarter people. In my case, it's really true."
And, as a result, many women are also grateful to Dr. Bharucha for seeking new answers and new tests with his colleagues for this all too common and embarrassing condition.
Posted on November 6th, 2013 by Admin
Certain types of "hard to treat" prostate cancer present an unanswerable challenge for physicians. That's a nicely worded sentence for very bad news for the patient. After hormone treatment yields no response, the patient usually has two years or less to live. Surgery isn't possible because the tumor cannot be shrunk. The reality of the condition underscores the urgency of a new study at Mayo Clinic's Center for Individualized Medicine that uses the genomic information of the patient's tumor to find possible solutions, such as more targeted drugs. For more details on the study or to learn how you might participate, check the news release Mayo issued today.