g., minocycline), excitatory amino acid antagonists (e.g., topiramate, memantine), free radical scavengers (e.g., N-acetylcysteine, vitamins E/K), and antiapoptotic agents (e.g., erythropoietin, insulin-like growth factor-1). To translate these interventions to the clinical

arena, it is critical to determine their direct relevance to the human premature brain. Recent advanced neuropathologic studies of premature brain suggest that many cellular and molecular events demonstrable in experimental models appear to occur also in human PVL and that several of the agents just AZD2014 purchase observed, at least theoretically, could be useful. Yet, are they safe? Safety relates EPZ 6438 in considerable part to the likely duration of therapy required. How long should a preterm infant be treated to prevent PVL? The answer to this key question is not entirely known. Treatment with several of these agents for a day or two is quite different, in terms of safety, than when the duration must be many weeks. Indeed, considerable clinical evidence suggests that the insults responsible for PVL (hypoxic-ischemic or inflammatory or both) are chronic and cumulative, perhaps occurring over many weeks. Safety concerns concomitantly are greatly enhanced. Formulation of human clinical trials must be preceded by careful animal

studies that involve long durations of therapy. In spite of personal involvement over many years in basic and clinical research delineating pathogenetic mechanisms in PVL and discovering potential preventative interventions, too rapid a leap to the clinical arena cannot be justified. We must use direct neuropathologic studies of the premature brain to ensure relevance of experimental models to

the human lesion, and we must ensure that we will not harm the infant by translational therapies, especially when administered over relatively long periods. The most notable example of this lesson is illustrated best by the brain abnormalities occurring in the preterm infant. Beginning about 40 years ago, conventional neuroimaging has revealed a subsequent disturbance in myelination in preterm selleck chemicals infants with PVL. The cellular basis for this disturbance was not clearly revealed until the late 1990s and early 2000s when advanced neuropathologic studies by us (led by Dr. Hannah Kinney and Dr. Stephen Back) and others demonstrated that the predominant oligodendroglial cell in the human premature white matter is an early differentiating, premyelinating oligodendrocyte (pre-OL) and that this cell differentiates to myelin-producing mature OLs largely after term. This rapidly developing cell was demonstrated in experimental models to be vulnerable to injury by hypoxia ischemia and inflammation, the two key insults leading to human PVL.