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24 May 2012

Stem Cells for Spine Surgery: 7 Points From Dr. Richard Hynes

How we got here
Dr. Hynes was one of the many spine surgeons who participated in Medtronic's original trials for BMP-2 in the 1990's.  While scientists have known about the ability of stem cells and BMP to generate bone for several years, Medtronic was the first company to develop a safe and effective molecule to stimulate cell growth.  After completing the pre-market approval trials, the Food and Drug Administration granted approval for the BMP-2 product, Infuse, in 2002 for creating fusion in the Lumbar Spine placed through an anterior approach in a LT cage.

"In the original study, I experienced 100 percent of enrolled patients in my Practice achieving bone growth when combining BMP with the local cells that were already there," says Dr. Hynes.  "Local 'stem cells' respond to BMP and become activated thereby creating bone.  When I saw it worked in 100 percent of my enrolled patients, I was a true believer.  I have used it in my practice since the study and FDA approval going back greater than 10 years."

What has changed is our ability to concentrate stem cells; Dr. Hynes harvests the stem cells from the iliac crest to combine with the BMP.  It takes less than five minutes for his physician's assistant to harvest the cells, which are spun in a centrifuge while he begins the operation.  After 10-15 minutes, the cells are ready and Dr. Hynes adds a small amount to the surgical field along with the BMP.  The collagen sponge is placed within an interbody LT cage to keep the material from migrating.

"This has been an effective Bone Graft method and it has been an advantage for my patients who can avoid Iliac Bone Graft surgery and Donor Bone issues and cost," says Dr. Hynes.  "It doesn't add to my usual procedure time.  It does add a small cost, but I find it's worth the value proposition."

Since its inception and release, surgeons have been experimenting with its use in several different capacities, on- and off-label.  However, articles published in The Spine Journal in July 2011 suggest complication rates may be higher than the original studies reported.  Several physicians have reported positive and negative events based on individual practice date, and further research into its use will be necessary going forward.  As with all products, on label and off label use is routine practice and common place.  When used correctly, minimal side effects of swelling, seroma and osteolysis occur.

21 May 2012

Exposing Fetus To Plant Estrogen May Lead To Infertility In Women

A paper published in Biology of Reproduction's Papers-in-Press describes the effects of brief prenatal exposure to plant estrogens on the mouse oviduct, modeling the effects of soy-based baby formula on human infants. The results suggest that exposure to estrogenic chemicals in the womb or during childhood has the potential to affect a woman's fertility as an adult, possibly providing the mechanistic basis for some cases of unexplained female infertility

Earlier research suggested that neonatal exposure to plant estrogens or other environmental estrogens (synthetic substances that function similarly to the estrogen naturally produced in the body) may have long-term effects on adult female reproductive health. Wendy N. Jefferson, a researcher in the lab of Carmen J. Williams at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health, previously demonstrated that neonatal exposure to the plant estrogen genistein results in complete infertility in female adult mice. Causes of infertility included failure to ovulate, reduced ability of the oviduct to support embryo development before implantation, and failure of the uterus to support effective implantation of blastocyst-stage embryos. 

The team now reports that neonatal exposure to genistein changes the level of immune response in the mouse oviduct, known as mucosal immune response. Some of the immune response genes were altered beginning from the time of genistein treatment, while others were altered much later, when the mouse was in early pregnancy. Together, those changes led to harmfully altered immune responses and to compromised oviduct support for preimplantation embryo development, both of which would likely contribute to infertility. 

These findings raise the possibility that exposure to low levels of environmental or plant estrogens during sensitive developmental windows can alter the balance of the mucosal immune response in the uterus and oviduct. 

In the mouse, the window of development during which these changes can occur is found only in the neonatal period; in humans, development of the reproductive tract continues through the onset of puberty. Therefore, estrogenic chemical exposure to the female fetus, infant, child, and adolescent all have potential impacts on mucosal immunity in the reproductive tract and, therefore, on adult fertility. The authors present the view that limiting such exposures, including minimizing use of soy-based baby formula, is a step toward maintaining female reproductive health. 

How to Protect Your Back While Working at a Computer

If you start to think about how much time you spend sitting in front of the computer, you will probably feel guilty for reading the rest of this article as it will require even more of your time. By all means – get up and walk around a little bit. That is an easy way to take care of your back while sitting at a computer. So go ahead, go get a glass of water (properly hydrating will always contribute positively to pain management), but make sure to come back and read the rest to pick up some valuable tips:
  • Lumbar Support – Everyone's back is different, but everyone's back needs some sort of lumbar support. This does not require some sort of spongy pillow or an improvised, crumpled-up jacket. Actually, many people (including myself) prefer a hard, straight-backed chair, such as a dining room table chair. Next time you sit down for dinner, try to keep your lower back pressed flat against the back of the chair. Like chairs around the table, a computer chair's back inclines at a gradual angle away from you; engaging your abs and bracing your lower back flat against the base of the chair will make you sit straight – also useful for avoiding a chiding Mother at dinner.
  • Avoid Eyestrain Believe it – eyestrain will affect your back and here's how. Tension developed in the head and neck through ocular strain will cause your shoulders to tense up. Most people also have their hands extended towards the keyboard and mouse and rest their forearms on the desk in front of the keyboard. Basically, this is tension in the shoulder girdle, which attaches to the scapula and the back of the thoracic rib cage. This method of helping back pain already alluded to, but getting up or gazing out the window or at your office crush will contribute to a less painful back. 
  • Relax – You do not need me to tell you that working is stressful. Healthcare professionals conclude that stress has a measurable and real effect on your body's health. Make sure you do something to relax while working: a favorite Pandora station, listening to a random baseball game on, or making fun plans for after work always helps me to relax. 
  • Exercise – So, this one is not readily done while at the computer, although it is a great idea to move your legs around. Keeping your knees pent past 90 degrees for a long time can lead to back pain because the resulting knee pain will affect the way you walk. Straightening your legs out and flexing your feet at the ankle joint is a great way to keep your calves loose. Otherwise, you really need to have an exercise program in order to keep your back muscles strong. Abdominal exercises are great for keeping your back healthy, but make sure to strengthen your lower back and external oblique muscles just as much. For your upper back, exercises that involve rolling or pulling your shoulders back are great after extending your arms for so long towards the computer. Rowing machines and bent over rows (I suggest using a straight bar rather then an Olympic bar or dumbbells) are great for back strength. Know your limits though, and for those strong men out there, it’s a good rule of thumb to never lift over your body weight – even when deadlifting. Avoid injury at all costs.