No abstract

The regeneration of axons after a spinal cord injury or disease is attracting a significant amount of interest among researchers. Being able to assess these axons in terms of morphology, length and origin is essential to our understanding of the regeneration process. Recently, two specific axon tracers have gained much recognition; biotinylated dextran amine (BDA) 10 kDa as an anterograde tracer and cholera toxin-B as a retrograde tracer. However, there are still several complexities when using these tracers, including the volume that should be administered and the best administration site so that a significant amount of axons are labeled in the area of interest. In this article, we describe some simple procedures for injecting the tracers and detecting them. We also quantified the number of axons at different locations of the spinal cord. Our results show axons labeled from motor cortex injections traveled down to the lumbosacral spinal cord in 2 weeks, while BDA injections into the lateral vestibular nucleus and reticular formation took 3 weeks to label axons in the lumbosacral spinal cord. Moreover, this protocol outlines some basic procedures that could be used in any laboratory and gives insight into the number of axons labeled and how procedures could be tailored to meet specific researcher's needs.

Healthcare workers (HCW) are at higher risk of exposure to tuberculosis than the general population, thus screening upon start of employment and periodically thereafter for latent tuberculosis (TB) infection is required for work clearance in healthcare institutions. Treatment of latent TB infection (lTBI) is recommended in HCW, especially those with conditions that increase the risk of progression to active tuberculosis but despite evidence of benefit, adherence to treatment remains suboptimal. We undertook a retrospective study of healthcare employees at a large, academic, tertiary care institution in the United States and found that only 73% were compliant with treatment of lTBI. Side effects and duration of therapy were major reasons for lack of adherence. Closer follow up during the treatment course, and the use of alternative regimens such as the combination of isoniazid and rifapentine under direct observation for a shorter duration may improve compliance rates in healthcare workers in the future.