P. acnes-Driven Disease Pathology: Current Knowledge and Future Directions.

This review discusses the biology and behavior of Propionibacterium acnes (P. acnes), a dominant bacterium species of the skin biogeography thought to be associated with transmission, recurrence and severity of disease. More specifically, we discuss the ability of P. acnes to invade and persist in epithelial cells and circulating macrophages to subsequently induce bouts of sarcoidosis, low-grade inflammation and metastatic cell growth in the prostate gland. Finally, we discuss the possibility of P. acnes infiltrating the brain parenchyma to indirectly contribute to pathogenic processes in neurodegenerative disorders such as those observed in Parkinson's disease (PD).

The Glymphatic-Lymphatic Continuum: Opportunities for Osteopathic Manipulative Medicine.

The brain has long been thought to lack a lymphatic drainage system. Recent studies, however, show the presence of a brain-wide paravascular system appropriately named the glymphatic system based on its similarity to the lymphatic system in function and its dependence on astroglial water flux. Besides the clearance of cerebrospinal fluid and interstitial fluid, the glymphatic system also facilitates the clearance of interstitial solutes such as amyloid-ß and tau from the brain. As cerebrospinal fluid and interstitial fluid are cleared through the glymphatic system, eventually draining into the lymphatic vessels of the neck, this continuous fluid circuit offers a paradigm shift in osteopathic manipulative medicine. For instance, manipulation of the glymphatic-lymphatic continuum could be used to promote experimental initiatives for nonpharmacologic, noninvasive management of neurologic disorders. In the present review, the authors describe what is known about the glymphatic system and identify several osteopathic experimental strategies rooted in a mechanistic understanding of the glymphatic-lymphatic continuum.