The Impact of Completing X-Waiver Training and Clinical Addiction Exposure on Internal Medicine Residents Treating Patients With Opioid Use Disorder.

BACKGROUND: Treating opioid use disorder (OUD) with buprenorphine or methadone significantly reduces overdose and all-cause mortality. Prior studies demonstrate that clinicians and residents reported a lack of preparedness to diagnose or treat OUD. Little is known about how clinical exposure or buprenorphine X-waiver training impacts OUD care delivery by resident physicians. OBJECTIVE: Distinguish the effects of X-waiver training and clinical exposure with OUD on resident's knowledge, attitudes, feelings of preparedness, and practices related to OUD treatment provision. METHODS: From August 2021 to April 2022, we distributed a cross-sectional survey to internal medicine residents at a large academic training program. We analyzed associations between self-reported clinical exposure and X-waiver training across 4 domains: knowledge about best practices for OUD treatment, attitudes about patients with OUD, preparedness to treat OUD, and clinical experience with OUD. RESULTS: Of the 188 residents surveyed, 91 responded (48%). A majority of respondents had not completed X-waiver training (60%, n = 55) while many had provided clinical care to patients with OUD (65%, n = 59). Most residents had favorable attitudes about OUD treatment (97%). Both residents with clinical exposure to treating OUD and X-waiver training, and residents with clinical exposure without X-waiver training, felt more prepared to treat OUD (P < .0008) compared to residents with neither clinical exposure or X-waiver training or only X-waiver training. CONCLUSIONS: Residents with clinical exposure to treating OUD are more prepared to treat patients with OUD than those without clinical exposure. Greater efforts to incorporate clinical exposure to the treatment of OUD and education in internal medicine residency programs is imperative to address the opioid epidemic.

Brain-derived neurotrophic factor attracts geniculate ganglion neurites during embryonic targeting.

Geniculate axons are initially guided to discrete epithelial placodes in the lingual and palatal epithelium that subsequently differentiate into taste buds. In vivo approaches show that brain-derived neurotrophic factor (BDNF) mRNA is concentrated in these placodes, that BDNF is necessary for targeting taste afferents to these placodes, and that BDNF misexpression disrupts guidance. We used an in vitro approach to determine whether BDNF may act directly on geniculate axons as a trophic factor and as an attractant, and whether there is a critical period for responsiveness to BDNF. We show that BDNF promotes neurite outgrowth from geniculate ganglion explants dissected from embryonic day (E) 15, E18, infant, and adult rats cultured in collagen gels, and that there is a concentration optimum for neurite extension. Gradients of BDNF derived from slow-release beads caused the greatest bias in neurite outgrowth at E15, when axons approach the immature gustatory papillae. Further, neurites advanced faster toward the BDNF bead than away from it, even if the average amount of neurotrophic factor encountered was the same. We also found that neurites that contact BDNF beads did not advance beyond them. At E18, when axons would be penetrating pregustatory epithelium in vivo, BDNF continued to exert a tropic effect on geniculate neurites. However, at postnatal and adult stages, the influence of BDNF was predominantly trophic. Our data support a role for BDNF acting as an attractant for geniculate axons during a critical period that encompasses initial targeting but not at later stages.