OBJECTIVES
Endoscopic ablation of Barrett's esophagus can bury metaplastic glands under a layer of neosquamous epithelium. To explore the frequency and importance of buried metaplasia, we have conducted a systematic review of reports on endoscopic ablation.
METHODS
We performed computerized and manual searches for articles on the results of photodynamic therapy (PDT) and radiofrequency ablation (RFA) for Barrett's esophagus. We extracted information on the number of patients treated, biopsy protocol, biopsy depth, and frequency of buried metaplasia.
RESULTS
We found 9 articles describing 34 patients with neoplasia appearing in buried metaplasia (31 after PDT). We found five articles describing a baseline prevalence of buried metaplasia (before ablation) ranging from 0% to 28% . In 22 reports on PDT for 953 patients, buried metaplasia was found in 135 (14.2%); in 18 reports on RFA for 1,004 patients, buried metaplasia was found in only 9 (0.9%). A major problem limiting the conclusions that can be drawn from these reports is that they do not describe specifically how frequently biopsy specimens contained sufficient subepithelial lamina propria to be informative for buried metaplasia.
CONCLUSIONS
Endoscopic ablation can bury metaplastic glands with neoplastic potential but, even without ablation, buried metaplasia often is found in areas where Barrett's epithelium abuts squamous epithelium. Buried metaplasia is reported less frequently after RFA than after PDT. However, available reports do not provide crucial information on the adequacy of biopsy specimens and, therefore, the frequency and importance of buried metaplasia after endoscopic ablation remain unclear.
Cutaneous inoculation blastomycosis is a rare illness. We report a case of cutaneous inoculation blastomycosis in a patient who was inoculated after being struck by a projectile while performing yard work. We also review cases of cutaneous inoculation blastomycosis described elsewhere, to improve characterization of the syndrome.
Manipulations that increase dopamine (DA) signaling can enhance fear extinction, but the circuits involved remain unknown. DA neurons originating in the substantia nigra (SN) projecting to the dorsal striatum (DS) are traditionally viewed in the context of motor behavior, but growing data implicate this nigrostriatal circuit in emotion. Here we investigated the role of nigrostriatal DA in fear extinction. Activation of SN DA neurons with designer G-coupled receptors exclusively activated by designer drugs (G-DREADD) during fear extinction had no effect on fear extinction acquisition, but enhanced fear extinction memory and blocked the renewal of fear in a novel context; a pattern of data paralleled by cFos expression in the central amygdala. D1 receptors in the DS are a likely target mediating the effects of SN DA activation. D1-expressing neurons in the medial DS (DMS) were recruited during fear extinction, and G-DREADD-induced DA potentiated activity of D1-expressing neurons in both the DMS and the lateral DS (DLS). Pharmacological activation of D1 receptors in the DS did not impact fear extinction acquisition or memory, but blocked fear renewal in a novel context. These data suggest that activation of SN DA neurons and DS D1 receptors during fear extinction render fear extinction memory resistant to the disrupting effects of changes in contextual contingencies, perhaps by recruiting habitual learning strategies involving the DLS. Nigrostriatal DA thus represents a novel target to enhance long-term efficacy of extinction-based therapies for anxiety and trauma-related disorders.
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