Prevalence of potential candidates for electric-acoustic stimulation implant in a hearing-impaired population.

OBJECTIVE: To estimate the prevalence of potential electric-acoustic stimulation (EAS) implant candidates in a hearing-impaired population through a review of auditory examinations. METHODS: In total, 7356 patients underwent audiometric examination in our department between 2011 and 2014. The prevalence of patients meeting the audiometric criteria for EAS and standard cochlear implant (CI) was assessed. RESULTS: The percentage of EAS implant candidates meeting the pure-tone audiometric criteria was 0.71% (n=34) among the hearing-impaired individuals (n=4758) examined in our department, whereas 2.52% (n=120) met the criteria for standard CI. Among the 34 EAS implant candidates, 2 individuals (5.83%) received EAS implant surgery after approval of the EAS device in Japan. CONCLUSIONS: There was a lower prevalence of EAS implant candidates than standard CI candidates. Nevertheless, healthcare professionals should carefully examine the audiograms of patients with high frequency hearing loss with regard to meeting the indication criteria for EAS implant. This will enable patients to gain access to adequate information relating to further examinations and treatment options.

Antioxidative activities of 62 wild mushrooms from Nepal and the phenolic profile of some selected species.

Mushrooms have garnered immense popularity for their nutritional as well as medicinal values. The therapeutic potential of mushrooms in Nepal, a country well known for its biodiversity and natural medicinal resources, remains largely unstudied. Therefore, this study attempts to unveil the antioxidative properties of Nepalese wild mushrooms. Sixty-two wild mushroom samples were collected from several forests in different parts of Nepal. Ethanol and water extracts of the dried samples were tested for their antioxidative activities using total phenolic content (TPC), oxygen radical absorbance capacity (ORAC) assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing power (RP) assays. Ethanol extracts of samples belonging to the order Hymenochaetales showed significantly high activity in all the assays. Inonotus clemensiae had an exceptionally high TPC of 643.2 mg gallic acid equivalent (GAE)/g extract and also exhibited the lowest EC50 values in DPPH (0.081 mg/mL), ABTS (0.409 mg/mL), and EC0.5 value in reducing power (RP; 0.031 mg/mL) assays. High-performance liquid chromatography (HPLC) analysis of the top ten samples with the highest TPC was done to identify the phenolic compounds in the extracts, followed by liquid chromatography-mass spectrometry (LC-MS) analysis for some unknown compounds. These findings highlight the very strong antioxidative activity of Nepalese mushrooms, and paves the way for further research to explore their economic potential.

Wild Mushrooms in Nepal: Some Potential Candidates as Antioxidant and ACE-Inhibition Sources.

Twenty-nine mushrooms collected in the mountainous areas of Nepal were analyzed for antioxidant activity by different methods, including Folin-Ciocalteu, ORAC, ABTS, and DPPH assays. Intracellular H2O2-scavenging activity was also performed on HaCaT cells. The results showed that phenolic compounds are the main antioxidant of the mushrooms. Among studied samples, Inonotus andersonii, and Phellinus gilvus exhibited very high antioxidant activity with the phenolic contents up to 310.8 and 258.7 mg GAE/g extracts, respectively. The H2O2-scavenging assay on cells also revealed the potential of these mushrooms in the prevention of oxidative stress. In term of ACE-inhibition, results showed that Phlebia tremellosa would be a novel and promising candidate for antihypertensive studies. This mushroom exhibited even higher in vitro ACE-inhibition activity than Ganoderma lingzhi, with the IC50 values of the two mushrooms being 32 µ g/mL and 2 µ g/mL, respectively. This is the first time biological activities of mushrooms collected in Nepal were reported. Information from this study should be a valuable reference for future studies on antioxidant and ACE-inhibitory activities of mushrooms.

Adhesion of Escherichia coli onto quartz, hematite and corundum: extended DLVO theory and flotation behavior.

The adhesion of Escherichia coli onto quartz, hematite and corundum was experimentally investigated. A strain of E. coli was used that had the genes for expressing protein for silica precipitation. The maximum cell adhesion was observed at pH <4.3 for quartz and at pH 4.5-8.5 for corundum. For hematite, cell adhesion remained low at all pH values. The microbe-mineral adhesion was assessed by the extended DLVO theory approach. The essential parameters for calculation of microbe-mineral interaction energy (Hamaker constants and acid-base components) were experimentally determined. The extended DLVO approach could be used to explain the results of the adhesion experiments. The effect of E. coli on the floatability of three oxide minerals was determined and the results showed that E. coli can act as a selective collector for quartz at acidic pH values, with 90% of the quartz floated at 1.5 x 10(9)cells/ml. However, only 9% hematite and 30% corundum could be floated under similar conditions. By using E. coli and no reagents, it was possible to separate quartz from a hematite-quartz mixture with Newton's efficiency of 0.70. Removal of quartz from the corundum mixture was achieved by E. coli with Newton's efficiency of 0.62.

Progressive hearing loss in mice carrying a mutation in the p75 gene.

The neurotrophin receptor p75 (p75NTR) is expressed in the developmental stage of the cochlea. However, the role of the p75NTR in the inner ear remains to be established. In this study, we conducted electrophysiological and morphological analyses of the auditory function of mice carrying a mutation in the p75 gene at different longitudinal stages. The mice carrying a mutation in the p75 gene showed an age-related progressive hearing loss. At 1 month, there was no obvious morphological change in the cochlea of the mice carrying a mutation in the p75 gene compared to wild-type mice, except for a slight loss of spiral ganglion neurons (SGNs). Auditory function was not significantly different between both genotypes from 1 to up to 4 months of age. The mice carrying a mutation in the p75 gene started to show progressive hearing loss at 4 months, when both SGN degeneration and hair cell (HC) loss were observed at the basal turn. These results suggest that the neurotrophin receptor p75 may play a significant role in the maintenance of cochlear function, and that mice carrying a mutation in the p75 gene could be a good animal model of early onset progressive hearing loss.