Pathogenesis and Etiology of Ménière Disease: A Scoping Review of a Century of Evidence.

IMPORTANCE: Ménière disease is a rare chronic benign disorder of the inner ear with a natural history of multiple clinical phenotypes of variable severity and a tendency to burnout with time. Although multiple treatment modalities have been shown to improve the disease process-some adversely affecting cochleovestibular function-it remains uncertain whether one, several separate, or a combination of pathophysiologic mechanisms affect the disease process. A scoping review of the evidence underlying proposed pathophysiologic mechanisms of Ménière disease is needed to determine which processes are most likely to be etiopathogenic factors. OBSERVATIONS: Of the 4602 relevant articles found through Embase, Ovid, and PubMed, 444 met inclusion criteria. The most common reported causes of Ménière disease were autoimmune or immune-mediated, genetic, or structural dysfunction of the inner ear. During the study period from inception to March 2021, etiologic theories shifted from structural dysfunction to autoimmune and genetic causes of Ménière disease. CONCLUSIONS AND RELEVANCE: This scoping review found that Ménière disease is a multifactorial disease with lifelong comorbidities and loss of quality-associated life-years whose most commonly reported causes were structural dysfunction, immunologic damage, and genetic susceptibility. Recent studies have examined how autoinflammatory processes and vestibular migraine may be associated with Ménière disease. Large heterogeneity among studies may be explained by historical differences in the clinical understanding of the disease, as well as evolving intervention methodologies and practitioner expertise. Ménière disease is a multifactorial disease with lifelong comorbidities and loss of quality-associated life-years; therefore, future studies of reliable biomarkers of endolymphatic hydrops and real-time imaging are warranted to improve understanding and treatment.

Survey of Sensitivity to Fatty Acid-Amino Acid Conjugates in the Solanaceae.

Plants perceive insect herbivores via a sophisticated surveillance system that detects a range of alarm signals, including herbivore-associated molecular patterns (HAMPs). Fatty acid-amino acid conjugates (FACs) are HAMPs present in oral secretions (OS) of lepidopteran larvae that induce defense responses in many plant species. In contrast to eggplant (Solanum melongena), tomato (S. lycopersicum) does not respond to FACs present in OS from Manduca sexta (Lepidoptera). Since both plants are found in the same genus, we tested whether loss of sensitivity to FACs in tomato may be a domestication effect. Using highly sensitive MAP kinase (MAPK) phosphorylation assays, we demonstrate that four wild tomato species and the closely related potato (S. tuberosum) do not respond to the FACs N-linolenoyl-L-glutamine and N-linolenoyl-L-glutamic acid, excluding a domestication effect. Among other genera within the Solanaceae, we found that bell pepper (Capsicum annuum) is responsive to FACs, while there is a differential responsiveness to FACs among tobacco (Nicotiana) species, ranging from strong responsiveness in N. benthamiana to no responsiveness in N. knightiana. The Petunia lineage is one of the oldest lineages within the Solanaceae and P. hybrida was responsive to FACs. Collectively, we demonstrate that plant responsiveness to FACs does not follow simple phylogenetic relationships in the family Solanaceae. Instead, sensitivity to FACs is a dynamic ancestral trait present in monocots and eudicots that was repeatedly lost during the evolution of Solanaceae species. Although tomato is insensitive to FACs, we found that other unidentified factors in M. sexta OS induce defenses in tomato.