(8/30/02 1:57 am)
What is Fibromuscular Dysplasia (FMD)? |
What is Fibromuscular Dysplasia (FMD)?
FMD is a disease of blood vessels that causes narrowings (stenosis) and balloonings (aneurysms). It is different to atherosclerosis, or "hardening of the arteries". There is no inflammation of arteries, which distinguishes it from vasculitis, where inflammation is present.
Five pathological subtypes of FMD have been described. By far the commonest is "medial fibroplasia", which usually produces alternate narrowing and ballooning, the classic "string of beads" appearance on angiography.
Which arteries are affected?
Involvement of the kidney arteries is most commonly recognised, usually because of the development of high blood pressure. The arteries to the brain and the legs are also commonly affected. Less commonly, involvement of the arteries to the bowel and the heart may be apparent.
Who does FMD affect?
FMD affects women three times as often as men. The most common age at diagnosis is between 30 and 50 years, however, any age may be affected.
How common is FMD?
Disease of the kidney arteries accounts for between 1-in-50 and 1-in-20 cases of high blood pressure seen at high blood pressure clinics, and for up to 1-in-5 children with high blood pressure. FMD is the most common kidney artery disease causing high blood pressure in patients younger than 40.
Estimates of how common FMD is depend upon the way it is looked for. FMD has been found in 1-in-50 to 1-in-8 people with normal blood pressure, and approximately 1-in-10 patients undergoing investigation for underlying causes of high blood pressure. FMD may, therefore, be more prevalent than previously appreciated, and almost certainly remains undiagnosed in less severely affected patients.
How may FMD present?
FMD predominantly affects young females and can lead to high blood pressure and stroke. FMD is frequently not detected until damage to organs has occurred, so that shrinkage of the kidney is unfortunately often present at diagnosis. Interference with blood circulation to the brain, legs or bowel may also produce symptoms. With increasing age, atherosclerosis becomes the most common cause of these symptoms.
How is FMD diagnosed?
FMD may be suspected in patients, particularly young patients, presenting with any of the problems mentioned above. Blood flowing through narrowed arteries produces turbulence which may be heard with a stethoscope. This is called a bruit. Ultrasound scans can detect turbulence and changes in blood flow in a wide range of arteries. Nuclear (or radioisotope scans) of the kidneys may show reduced or delayed blood flow to one or both kidneys. All of these can indicate that there is a narrowing of an artery, however, only angiography (the injection of dye into the artery) can definitely diagnose FMD. The most common lesion is the multifocal lesion, consisting of alternating narrowings and widenings of the artery producing a "string of beads" appearance. Less commonly, lesions may appear as focal (short, single) or tubular (long narrowings of even diameter).
How is FMD treated?
The first step is to determine if FMD is responsible for the presenting problem. For example, a patient may have high blood pressure and FMD, but not high blood pressure caused by FMD. In a patient with high blood pressure, the measurement of renin levels in the veins draining the kidneys is essential in determining the relationship of the FMD to high blood pressure. The results of all tests together with the patient's blood pressure level, any effects of the blood pressure on the heart, and any other medical conditions are all considered. If treatment is indicated, angioplasty,(News) where a balloon is inflated inside the artery to open it up, is the preferred and usual treatment. If, as is rarely the case, the lesionis not suitable for angioplasty, an operation may be possible and recommended.
What causes FMD?
At this stage, the cause of FMD is unknown.(Medical journals) The following facts are known and may provide clues to the cause:
Females are most frequently affected
The most common age for diagnosis is between 30 and 50 years
In the kidney arteries, involvement is most often on the right or bilateral
Several arteries may be affected in the one patient
More than one member of a family may be affected.
(8/30/02 4:27 am)
Adult Stem Cell Research and Blood Vessels|
MINNEAPOLIS / ST. PAUL -- Researchers at the University of Minnesota Stem Cell Institute (SCI) have demonstrated, for the first time, the ability of adult bone marrow stem cells to expand in vitro as endothelial cells (which line blood- and lymphatic vessels) and then engraft in vivo and contribute to new growth of blood vessels (neoangiogenesis). The findings will be published in the February 1, 2002 issue of the Journal of Clinical Investigation.
"These lab results demonstrate the potential of adult bone marrow stem cells to differentiate beyond mesenchymal cells, into cells of the endothelium," said Catherine Verfaillie, M.D., director of the University of Minnesota Stem Cell Institute and author of the research. "What we have seen is the ability of these cells to feed the blood vessels of tumors and to heal the blood vessels surrounding wounds. The findings suggest that these adult stem cells may be an ideal source of cells for clinical therapy. For example, we can envision the use of these stem cells for therapies against cancer tumors by, for instance, introducing anti-angiogenesis genes. Or, they could be used to heal wounds such as ulcers or diabetic wounds or to treat atherosclerosis."
Verfaillie and her colleagues announced late last year that these cells, called multipotent adult progenitor cells (MAPCs), demonstrate the potential to differentiate beyond mesenchymal cells, into cells of the visceral mesodermal origin, such as endothelium, and may be capable of differentiating into nonmesodermal cell types, such as neurons, astrocytes, oligodendrocytes, and liver.
The paper can be found at www.jci.org.
The objective of the Stem Cell Institute is to further our understanding of the potential of stem cells to improve human and animal health. The SCI is a part of the University of Minnesota's Academic Health Center and is an interdisciplinary center with member faculty representing a diverse group of university schools, colleges and centers. For online information about the University of Minnesota's Stem Cell Institute, go to www1.umn.edu
Editor's Note: The original news release can be found at www1.umn.edu/urelate/news...cells.html
Note: This story has been adapted from a news release issued by University Of Minnesota for journalists and other members of the public. If you wish to quote from any part of this story, please credit University Of Minnesota as the original source. You may also wish to include the following link in any citation:
Edited by: fmdqadmin at: 8/31/02 11:54:01 am