But do they reach their destination in sufficient quantities? Scientists of the PTB have developed a highly sensitive measuring method with which the efficiency of this therapy can be investigated: Small magnetic particles which are situated on the planted gene or on the planted cell can with the aid of an external magnetic field be specifically directed to the location of the damage. There the researchers determine, accurate to the picogram per cell, the quantity of the magnetic material “ and thus also the quantity of the therapeutically effective genes or cells. In a joint study with the University of Bonn it became clear: By means of the magnetic method it is possible to dramatically increase the efficiency of the gene transfer in comparison to the non-magnetic method.
Magnetic nanoparticles can support or even enable gene transfer under clinically relevant experimental conditions. For the transduction of human cells, gene carriers were coupled to magnetic nanoparticles and dragged into the cells by magnetic field gradients. The efficiency of magnetic transduction turned out to be much higher than the nonmagnetic procedure. An additional welcome side effect is the "magnetization" of the cells after the incorporation of nanoparticles. This may enable the targeted transport of the cells to regions of interest.
A closer look at the underlying mechanism of magnetic gene transfer was taken by the quantification of the magnetic material that was delivered to the cells. The required highly sensitive measurements in the range of a few picogramm per cell were made by PTB using magnetorelaxometry. The good correlation between measurement data and gene transfer encourages to use magnetorelaxometry for monitoring the efficiency of gene and cell transfer, possibly even in vivo.
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Women and men with a prior history of breast cancer have a twofold to threefold risk of developing melanoma. Women with a prior history of thyroid cancer have a twofold risk of developing melanoma. A higher socioeconomic class has been linked to a higher incidence of melanoma, which Dr. Rigel attributes to this group being able to afford more vacations and leisure time that could result in more sun exposure. Airline flight personnel had a higher rate of melanoma when the incidence of melanoma was examined by occupation. Male drivers have been found to have a higher incidence of skin cancers on the left side of the body compared to right side of the body. Taller men were found to have a higher incidence of melanoma than shorter men, with men in the top quartile of height twice as likely to develop melanoma as men in the bottom quartiles of height. Use of tanning beds is a major risk factor for melanoma, with studies showing people who use tanning beds have a higher melanoma risk, a higher incidence of getting a second melanoma, and are younger when they develop melanoma. Patients with a history of dysplastic nevi, or non-cancerous moles that share some of the features of melanoma, and a family history of melanoma have a 50 percent greater risk of developing melanoma.
"Dermatologists continually look for clues as to who is most likely to develop melanoma, and this ongoing research will likely help more people understand their own risk factors and may convince them to get regular skin cancer screenings," said Dr. Rigel. "Unfortunately, we expect skin cancer rates to continue to climb. But, identifying additional risk factors for melanoma could lead to the early detection and successful treatment of this potential killer." People who are known to have any of the risk factors for melanoma should regularly conduct skin self-examinations and see a dermatologist.
For more information on melanoma, go to the "SkinCancerNet" section of www.skincarephysicians, a Web site developed by dermatologists that provides patients with up-to-date information on the treatment and management of disorders of the skin, hair and nails.
Headquartered in Schaumburg, Ill., the American Academy of Dermatology (Academy), founded in 1938, is the largest, most influential, and most representative of all dermatologic associations. With a membership of more than 15,000 physicians worldwide, the Academy is committed to: advancing the diagnosis and medical, surgical and cosmetic treatment of the skin, hair and nails; advocating high standards in clinical practice, education, and research in dermatology; and supporting and enhancing patient care for a lifetime of healthier skin, hair and nails. For more information, contact the Academy at 1-888-462-DERM (3376) or www.aad.
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