Prevalence of Cochlear Nerve Deficiency and Hearing Device Use in Children With Single-Sided Deafness.

OBJECTIVE: This study aimed to assess the prevalence of cochlear nerve deficiency (CND) in a cohort of pediatric patients with single-sided deafness (SSD). A secondary objective was to investigate trends in intervention and hearing device use in these children. STUDY DESIGN: Case series with chart review. SETTING: Pediatric tertiary care center. METHODS: Children ages 0 to 21 years with SSD (N = 190) who underwent computerized tomography (CT) and/or magnetic resonance imaging (MRI) were included. Diagnostic criteria for SSD included unilateral severe-to-profound sensorineural hearing loss with normal hearing sensitivity in the contralateral ear. Diagnostic criteria for CND included neuroradiologist report of an "aplastic or hypoplastic nerve" on MRI or a "stenotic cochlear aperture" on CT. RESULTS: The prevalence of CND was 42% for children with CT only, 76% for children with MRI only, and 63% for children with both MRI and CT. Of the children with MRI and CT, there was a 90% concordance across imaging modalities. About 36% of children with SSD had hearing devices that routed sound to the normal hearing ear (ie, bone conduction hearing device/contralateral routing of signal), while only 3% received a cochlear implant. Approximately 40% did not have a hearing device. Hearing device wear time averaged 2.9 hours per day and did not differ based on cochlear nerve status. CONCLUSION: There is a high prevalence of CND in children with SSD. Cochlear nerve status should be confirmed via MRI in children with SSD. The limited implementation and use of hearing devices observed for children with SSD reinforce the need for increased support for early and continuous intervention.

Local and Visiting Physician Perspectives on Short Term Surgical Missions in Guatemala: A Qualitative Study.

OBJECTIVE: To explore the impact of short-term surgical missions (STMs) on medical practice in Guatemala as perceived by Guatemalan and foreign physicians. SUMMARY BACKGROUND DATA: STMs send physicians from high-income countries to low and middle-income countries to address unmet surgical needs. Although participation among foreign surgeons has grown, little is known of the impact on the practice of foreign or local physicians. METHODS: Using snowball sampling, we interviewed 22 local Guatemalan and 13 visiting foreign physicians regarding their perceptions of the impact of Guatemalan STMs. Interviews were transcribed verbatim, iteratively coded, and analyzed to identify emergent themes. Findings were validated through triangulation and searching for disconfirming evidence. RESULTS: We identified 2 overarching domains. First, the delivery of surgical care by both Guatemalan and foreign physicians was affected by practice in the STM setting. Differences from usual practice manifested as occasionally inappropriate utilization of skills, management of postoperative complications, the practice of perioperative care versus "pure surgery," and the effect on patient-physician communication and trust. Second, both groups noted professional and financial implications of participation in the STM. CONCLUSIONS: While Guatemalan physicians reported a net benefit of STMs on their careers, they perceived STMs as an imperfect solution to unmet surgical needs. They described missed opportunities for developing local capacity, for example through education and optimal resource planning. Foreign physicians described costs that were manageable and high personal satisfaction with STM work. STMs could enhance their impact by strengthening working relationships with local physicians and prioritizing sustainable educational efforts.

Separate checkpoints regulate splenic plasma cell accumulation and IgG autoantibody production in Lyn-deficient mice.

Accumulation of plasma cells and autoantibodies against nuclear antigens characterize both human and murine lupus. Understanding how these processes are controlled may reveal novel therapeutic targets for this disease. Mice deficient in Lyn, a negative regulator of B and myeloid cell activity, develop lupus-like autoimmune disease. Here, we show that lyn(-) (/) (-) mice exhibit increased splenic plasmablasts and plasma cells and produce IgM against a wide range of self-antigens. Both events require Btk, a target of Lyn-dependent inhibitory pathways. A Btk-dependent increase in the expression of the plasma cell survival factor IL-6 by lyn(-) (/) (-) splenic myeloid cells was also observed. Surprisingly, IL-6 was not required for plasma cell accumulation or polyclonal IgM autoreactivity in lyn(-/-) mice. IL-6 was, however, necessary for the production of IgG autoantibodies, which we show are focused towards a limited set of nucleic acid-containing and glomerular autoantigens in lyn(-) (/) (-) mice. A similar uncoupling of plasma cell accumulation from IgG autoantibodies was seen in lyn(+/-) mice. Plasma cell accumulation and polyclonal IgM autoreactivity are therefore controlled separately from, and are insufficient for, the production of IgG against lupus-associated autoantigens. Regulators of either of these two checkpoints may be attractive therapeutic targets for lupus.