Hearing-related quality of life outcomes for Singaporean children using hearing aids or cochlear implants.

OBJECTIVES: The Children Using Hearing Devices Quality of Life Questionnaire (CuHDQOL) is a new parent-administered hearing-specific questionnaire for children fitted with hearing devices. The aim of this study was to assess outcomes for hearing-impaired children in Singapore using this measure, as well as to examine its applicability for use in a clinical setting. MATERIALS AND METHODS: The CuHDQOL has 26 items, uses a recall period of 1 month, and is divided into three sections: parental perspectives and expectations (eight items), impact on the family (eight items) and hearing-related quality of life (QOL) of the child (10 items). Responses are made on a 5-point Likert scale, and transformed to a score from 0-100. Twenty-two parents of children with hearing aids and 14 parents of children with cochlear implants completed the CuHDQOL. RESULTS: The mean total CuHDQOL scores was 62/100 for the children using hearing aids and 53/100 for children with cochlear implants. Scores for the children using hearing aids were higher across all subscales, with a linear regression showing this to be significant for the parental perspectives and expectations subscale (B=-10.58, P=0.041). Analyses of Variance showed that both the 'Parent Perspective and Expectations' and the 'Hearing-related QOL' subscales were significantly higher than the 'Impact on Family' subscale for both groups (P≤0.003). CONCLUSIONS: The CuHDQOL was found to be a simple, efficient questionnaire that could easily be incorporated into clinical practice to provide a more holistic evaluation of a child's outcomes post intervention, and/or to monitor their progress over time.

Crystal structures of the Streptomyces coelicolor TetR-like protein ActR alone and in complex with actinorhodin or the actinorhodin biosynthetic precursor (S)-DNPA.

Actinorhodin, an antibiotic produced by Streptomyces coelicolor, is exported from the cell by the ActA efflux pump. actA is divergently transcribed from actR, which encodes a TetR-like transcriptional repressor. We showed previously that ActR represses transcription by binding to an operator from the actA/actR intergenic region. Importantly, actinorhodin itself or various actinorhodin biosynthetic intermediates can cause ActR to dissociate from its operator, leading to derepression. This suggests that ActR may mediate timely self-resistance to an endogenously produced antibiotic by responding to one of its biosynthetic precursors. Here, we report the structural basis for this precursor-mediated derepression with crystal structures of homodimeric ActR by itself and in complex with either actinorhodin or the actinorhodin biosynthetic intermediate (S)-DNPA [4-dihydro-9-hydroxy-1-methyl-10-oxo-3-H-naphtho-[2,3-c]-pyran-3-(S)-acetic acid]. The ligand-binding tunnel in each ActR monomer has a striking hydrophilic/hydrophobic/hydrophilic arrangement of surface residues that accommodate either one hexacyclic actinorhodin molecule or two back-to-back tricyclic (S)-DNPA molecules. Moreover, our work also reveals the strongest structural evidence to date that TetR-mediated antibiotic resistance may have been acquired from an antibiotic-producer organism.