Author Interviews, JAMA, Orthopedics / 12.09.2016

MedicalResearch.com Interview with: R. Grant Steen, PhD Medical Affairs, Bioventus LLC Durham, North Carolina MedicalResearch.com: What is the background for this study? What are the main findings? Response: When we started this research, it was really only guesswork as to how big a problem fracture nonunion really is. What we've done is to work with an enormous database of patient health claims, with two goals. First, we wanted to characterize how common fracture nonunion is among patients across a wide age range. Second, we wanted to identify risk factors that make a patient more likely to have problems healing. We've now succeeded in both aims. We know that roughly 5% of fracture patients will go to nonunion, and we know a whole host of risk factors that predispose them to do so. Most of the risk factors that we've identified—with a few exceptions—would not be a surprise to physicians who treat fracture patients. However, what we've done is to put all of these risk factors in a broader context, so that we know which risk factors are most important and which are less so. For example, it has been known for a long time that smoking is a risk factor for nonunion. What we've shown is that, in the scheme of things, it's not all that important. Let me be more precise here, because this is an important point. If all you know about a patient is that they smoke, we've shown that smoking is associated with a 62% increase in risk of nonunion. That's a lot. But, as you learn more about that patient and can factor that new knowledge into a risk prediction, it turns out that smoking, all by itself, increases the risk of nonunion by only about 20%. However, smoking is a surrogate marker for a range of other risk factors that also increase risk, including male gender, cardiovascular disease, obesity, vitamin D deficiency, alcoholism, and so on. Once you factor these separate risk factors into your new nonunion prediction, you have a much more nuanced—and probably much more accurate—prediction of nonunion risk. (more…)
Author Interviews, Gastrointestinal Disease, PLoS / 03.04.2015

MedicalResearch.com Interview with: Ricardo Battaglino, Ph.D. Department of Mineralized Tissue Biology The Forsyth Institute, Cambridge, Massachusetts Department of Oral Medicine, Infection, and Immunity Harvard School of Dental Medicine, Boston, Massachusetts,MedicalResearch.com Interview with: Ricardo Battaglino, Ph.D. Department of Mineralized Tissue Biology The Forsyth Institute, Cambridge, Massachusetts Department of Oral Medicine, Infection, and Immunity Harvard School of Dental Medicine, Boston, Massachusetts Medical Research: What is the background for this study? What are the main findings? Dr. Battaglino: Mutations in sorting nexin 10 (Snx10) have recently been found to account for roughly 4% of all human malignant osteopetrosis, some of them fatal. To study the disease pathogenesis, we investigated the expression of Snx10 and created mouse models in which Snx10 was knocked down globally or knocked out in osteoclasts. We found that Snx10, a molecule expressed in osteoclasts, was also expressed in the stomach. Studies in tissue specific or global knock-down mice showed that Snx10 deficiency resulted in a phenotype that was a consequence of deficiencies in both osteoclasts and gastric zymogenic cells. Our studies add to a growing list of genes, including atp6i (Tcirg1), whose expression is required both in bone and stomach to maintain normal gastric acidification and calcium absorption. Medical Research: What should clinicians and patients take away from your report? Dr. Battaglino: Our work provides additional insight into the mechanisms governing the regulation of bone accrual by the gastrointestinal tract. Because osteopetrorickets has not been described clinically in Snx10-related osteopetrosis, these findings highlight the importance of considering impaired acidification in both stomach and bone in osteopetrotic patients with mutations in SNX10 and other genes with similar patterns of expression and activities. Reliance solely on hematopoietic stem cell transplantation can leave hypocalcemia uncorrected with sometimes fatal consequences. Because defects in gastric differentiation and/or gastric acidification may cause or contribute to hypocalcemia, bone insufficiency, and early death, our results suggest that dietary calcium supplementation could be a life-saving intervention in these patients. (more…)