Bladder control restored to men with spinal cord injuries
Magnetic stimulation of the lower spinal cord through the skin enabled five men with spinal-cord injuries to recover significant urination control for up to two weeks. The new approach could enhance patients' quality of life by increasing independence and reducing reliance on a catheter to empty the bladder. In a UCLA study of five men, neuroscientists stimulated the lower spinal cord through the skin with a magnetic device placed at the lumbar spine. The research is the first to show that the technique enables people with spinal-cord injuries to recover significant bladder control for up to four weeks between treatments. The findings were published Aug. 22, 2018, in Scientific Reports. The treatment improved the men's quality of life by an average of 60 percent (according to a questionnaire they completed before and after the study). And if the technique is replicable on other people, it could help reduce the social stigma and health risks linked to frequent catheter use. "We were excited to see a positive effect in all five patients after only four sessions of mild magnetic stimulation," said Daniel Lu, the study's principal investigator and an associate professor of neurosurgery at the David Geffen School of Medicine at UCLA. "The benefit persisted from two to four weeks, suggesting that the spinal cord's neural circuitry retains a 'memory' of the treatment." Relying on a catheter long-term can be dangerous, because the procedure can introduce bacteria that lead to urinary tract infections and permanent scarring. Bladder problems after spinal cord injuries can also lead to kidney failure and death. Lu hopes his laboratory's research will ultimately reduce those risks by eliminating the need for catheters. The article was titled "A Proof-of-Concept Study of Transcutaneous Magnetic Spinal Cord Stimulation for Neurogenic Bladder."
When it comes to regrowing tails, neural stem cells are key
Cut off a salamander's tail and, in a few weeks, a near-perfect replacement grows. Do the same to a lizard and a new tail will regrow, but it won't be the same as the original. By comparing tail regeneration between the two animals, researchers at the University of Pittsburgh School of Medicine found that stem cells in the spinal cord are the ultimate limiting factor. This finding, published Aug. 13, 2018, in Proceedings of the National Academy of Sciences, answers the longstanding question of why tail regeneration is perfect in the salamander and imperfect in the lizard, and may serve as a stepping stone to understanding why mice can't regenerate their tails at all. "The traditional animal model for regeneration is the salamander," said senior author Thomas Lozito, assistant professor in Pitt's Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering and the McGowan Institute for Regenerative Medicine. "Salamanders can regenerate a wide variety of tissues – brain, heart, parts of their eyes, limbs, tails – but they have whole classes of molecule types and tissues that just aren't found in mammals, so we really haven't been able to apply very much of what we found in the salamander to humans." According to Lozito, if the goal is to translate regeneration research to non-regenerating species like humans, the lizard is a much better model than the salamander. Lizards are the closest relative to mammals that can regenerate an appendage, and they have a similar genome and biochemistry. But lizards cannot regenerate lost limbs at all, and their regenerated tails are much simpler than the originals. Understanding what separates perfect regeneration in the salamander from imperfect regeneration in the lizard lays the groundwork for bridging the gap to non-regenerating species, Lozito said. For their study, the researchers took neural stem cells from a salamander and inserted them into a lizard's regenerating tail stump. The goal was to see what holds back tail regeneration in the lizard: the biochemical environment or the lizard's native stem cells. They found the transplanted salamander stem cells retained their ability to differentiate into multiple cell types, including neurons. By contrast, lizard neural stem cells could become only glial cells, which don't process the messages that direct movement and feeling. The lizard's neural stem cells driving regeneration in the lizard are not "true" neural stem cells at all, the researchers said. Although they check many of the classic boxes, they fall short of a defining characteristic - the ability to spring forth a diversity of cell types. These neural stem cells can't produce the different cell types that would be needed to recreate the asymmetries of the original spinal cord, which in turn stymies the development of bony vertebrae. That explains why there isn't perfect tail regeneration in the lizard, Lozito said. The article was titled "Differences in neural stem cell identity and differentiation capacity drive divergent regenerative outcomes in lizards and salamanders."
Study results may benefit patients with knee OA, meniscal tears
In an Arthritis & Rheumatology study of 221 patients with knee osteoarthritis and meniscal tears, increases in inflammation of the synovial membrane (synovitis) – whether persistently extensive or intermittent – were linked with cartilage damage over time. Over 18 months, effusion-synovitis was persistently minimal in 45.3 percent of the patients and persistently extensive in 21.3 percent. The remaining 33.5 percent had minimal synovitis on one occasion and extensive on the other. "Our findings suggest that individuals with synovitis may be at greater risk for cartilage damage. We find this particularly relevant as synovitis is a potentially modifiable feature of osteoarthritis," said lead author Lindsey Macfarlane, of Brigham and Women's Hospital and Harvard Medical School. "Further research on whether treatment of synovitis mitigates future cartilage damage could help advance treatment paradigms." The article, published Aug. 22, 2018, is titled "Association of Changes in Effusion-Synovitis and Progression of Cartilage Damage Over 18 Months in Patients with Osteoarthritis and Meniscal Tear."