Low anti-staphylococcal IgG responses in granulomatosis with polyangiitis patients despite long-term Staphylococcus aureus exposure

Chronic nasal carriage of the bacterium Staphylococcus aureus in patients with the autoimmune disease granulomatosis with polyangiitis (GPA) is a risk factor for disease relapse. To date, it was neither known whether GPA patients show similar humoral immune responses to S. aureus as healthy carriers, nor whether specific S. aureus types are associated with GPA. Therefore, this study was aimed at assessing humoral immune responses of GPA patients against S. aureus antigens in relation to the genetic diversity of their nasal S. aureus isolates. A retrospective cohort study was conducted, including 85 GPA patients and 18 healthy controls (HC). Humoral immune responses against S. aureus were investigated by determining serum IgG levels against 59 S. aureus antigens. Unexpectedly, patient sera contained lower anti-staphylococcal IgG levels than sera from HC, regardless of the patients' treatment, while total IgG levels were similar or higher. Furthermore, 210 S. aureus isolates obtained from GPA patients were characterized by different typing approaches. This showed that the S. aureus population of GPA patients is highly diverse and mirrors the general S. aureus population. Our combined findings imply that GPA patients are less capable of mounting a potentially protective antibody response to S. aureus than healthy individuals

Tinnitus after Simultaneous and Sequential Bilateral Cochlear Implantation

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The alpha-motoneuron pool as transmitter of rhythmicities in cortical motor drive

OBJECTIVE: Investigate the effectiveness and frequency dependence of central drive transmission via the alpha-motoneuron pool to the muscle. METHODS: We describe a model for the simulation of alpha-motoneuron firing and the EMG signal as response to central drive input. The transfer in the frequency domain is investigated. Coherence between stochastical central input and EMG is also evaluated. RESULTS: The transmission of central rhythmicities to the EMG signal relates to the spectral content of the latter. Coherence between central input to the alpha-motoneuron pool and the EMG signal is significant whereby the coupling strength hardly depends on the frequency in a range from 1 to 100 Hz. Common central input to pairs of alpha-motoneurons strongly increases the coherence levels. The often-used rectification of the EMG signal introduces a clear frequency dependence. CONCLUSIONS: Oscillatory phenomena are strongly transmitted via the alpha-motoneuron pool. The motoneuron firing frequencies do play a role in the transmission gain, but do not influence the coherence levels. Rectification of the EMG signal enhances the transmission gain, but lowers coherence and introduces a strong frequency dependency. We think that it should be avoided. SIGNIFICANCE: Our findings show that rhythmicities are translated into alpha-motoneuron activity without strong non-linearities

Nonlinear photonics in AlGaAs photonics nanowires: self phase and cross phase modulation

AlGaAs nanowires are ideal waveguides for the observation of nonlinear effects. The sub-micron geometry and tight field confinement, due to the high index contrast between core and cladding, yield very intense pulsed beams at low power levels. Observations of Kerr nonlinearities are thus possible at power levels of a few watts in just a few millimeters of propagation. By using pulses of 52 W of peak power we obtain a 0.9? nonlinear phase shift from self-phase modulation. By way of cross-polarised co-propagating pulses we also obtain a crossphase modulation to self-phase modulation ratio of 0.88 at 1557 nm. Nonlinear transmission arising from three photon absorption is also analysed. We find good agreement between our experimental results and those from our simulations based on a nonlinear Schrödinger model. These results may eventually lead to the development of nonlinear all-optical devices operating in sub-micrometer interaction lengths with but a few watts of power. © 2007 IEEE

Cost-Utility of Bilateral Versus Unilateral Cochlear Implantation in Adults: A Randomized Controlled Trial

OBJECTIVE: To study the cost-utility of simultaneous bilateral cochlear implantation (CI) versus unilateral CI. STUDY DESIGN: Randomized controlled trial (RCT). SETTING: Five tertiary referral centers. PATIENTS: Thirty-eight postlingually deafened adults eligible for cochlear implantation. INTERVENTIONS: A cost-utility analysis was performed from a health insurance perspective. MAIN OUTCOME MEASURES: Utility was assessed using the HUI3, TTO, VAS on hearing, VAS on general health and EQ-5D. We modeled the incremental cost per quality-adjusted life year (QALY) of unilateral versus bilateral CI over periods of 2, 5, 10, 25 years, and actual life-expectancy. RESULTS: Direct costs for unilateral and bilateral CI were euro43,883 +/- euro11,513(SD) and euro87,765 +/- euro23,027(SD) respectively. Annual costs from the second year onward were euro3,435 +/- euro1,085(SD) and euro6,871 +/- euro2,169(SD), respectively. A cost-utility analysis revealed that a second implant became cost-effective after a 5- to 10-year period, based on the HUI3, TTO, and VAS on hearing. CONCLUSION: This is the first study that describes a cost-utility analysis to compare unilateral with simultaneous bilateral CI in postlingually deafened adults, using a multicenter RCT. Compared with accepted societal willingness-to-pay thresholds, simultaneous bilateral CI is a cost-effective treatment for patients with a life expectancy of 5-10 years or longer

Enhanced third-order nonlinear effects in optical AlGaAs nanowires

We report the first observation of enhanced third-order nonlinear effects in AlGaAs nanowires. AlGaAs nanowaveguides with widths varying from 100 to 600nm were fabricated and characterized. Nonlinear phase shifts of ∼π were experimentally observed at 1.55μm with peak powers of 30-40W in 600μm long, 550nm wide guides

Objective and Subjective Measures of Simultaneous vs Sequential Bilateral Cochlear Implants in Adults: A Randomized Clinical Trial

Item does not contain fulltextImportance: To date, no randomized clinical trial on the comparison between simultaneous and sequential bilateral cochlear implants (BiCIs) has been performed. Objective: To investigate the hearing capabilities and the self-reported benefits of simultaneous BiCIs compared with those of sequential BiCIs. Design, Setting, and Participants: A multicenter randomized clinical trial was conducted between January 12, 2010, and September 2, 2012, at 5 tertiary referral centers among 40 participants eligible for BiCIs. Main inclusion criteria were postlingual severe to profound hearing loss, age 18 to 70 years, and a maximum duration of 10 years without hearing aid use in both ears. Data analysis was conducted from May 24 to June 12, 2016. Interventions: The simultaneous BiCI group received 2 cochlear implants during 1 surgical procedure. The sequential BiCI group received 2 cochlear implants with an interval of 2 years between implants. Main Outcomes and Measures: First, the results 1 year after receiving simultaneous BiCIs were compared with the results 1 year after receiving sequential BiCIs. Second, the results of 3 years of follow-up for both groups were compared separately. The primary outcome measure was speech intelligibility in noise from straight ahead. Secondary outcome measures were speech intelligibility in noise from spatially separated sources, speech intelligibility in silence, localization capabilities, and self-reported benefits assessed with various hearing and quality of life questionnaires. Results: Nineteen participants were randomized to receive simultaneous BiCIs (11 women and 8 men; median age, 52 years [interquartile range, 36-63 years]), and another 19 participants were randomized to undergo sequential BiCIs (8 women and 11 men; median age, 54 years [interquartile range, 43-64 years]). Three patients did not receive a second cochlear implant and were unavailable for follow-up. Comparable results were found 1 year after simultaneous or sequential BiCIs for speech intelligibility in noise from straight ahead (difference, 0.9 dB [95% CI, -3.1 to 4.4 dB]) and all secondary outcome measures except for localization with a 30 degrees angle between loudspeakers (difference, -10% [95% CI, -20.1% to 0.0%]). In the sequential BiCI group, all participants performed significantly better after the BiCIs on speech intelligibility in noise from spatially separated sources and on all localization tests, which was consistent with most of the participants' self-reported hearing capabilities. Speech intelligibility-in-noise results improved in the simultaneous BiCI group up to 3 years following the BiCIs. Conclusions and Relevance: This study shows comparable objective and subjective hearing results 1 year after receiving simultaneous BiCIs and sequential BiCIs with an interval of 2 years between implants. It also shows a significant benefit of sequential BiCIs over a unilateral cochlear implant. Until 3 years after receiving simultaneous BiCIs, speech intelligibility in noise significantly improved compared with previous years. Trial Registration: trialregister.nl Identifier: NTR1722

Effect of unilateral and simultaneous bilateral cochlear implantation on tinnitus: A Prospective Study

OBJECTIVES/HYPOTHESIS: To determine the effect of cochlear implantation on tinnitus perception in patients with severe bilateral postlingual sensorineural hearing loss and to demonstrate possible differences between unilateral and bilateral cochlear implantation. STUDY DESIGN: Prospective study. METHODS: Thirty-eight adult patients were included in this prospective study, as part of a multicenter randomized controlled trial investigating the benefits of bilateral cochlear implantation versus unilateral cochlear implantation. Pre- and postoperative tinnitus perception scores were evaluated, before and 1 year after implantation on three tinnitus questionnaires; the Tinnitus Handicap Inventory (THI), the Tinnitus Questionnaire (TQ), and a visual analogue scale for tinnitus burden. RESULTS: Before implantation, the tinnitus prevalence was 42.1% (16 of 38) in the whole study group. One year after implantation, the tinnitus questionnaire scores had decreased in 71.4% according to the TQ and 80.0% according to the THI. Tinnitus was induced after cochlear implantation in six patients, five in the bilateral and one in the unilateral group. CONCLUSIONS: Our study shows that cochlear implantation is effective in the reduction of tinnitus in patients with bilateral sensorineural hearing loss who suffered from preoperative tinnitus. Conversely, tinnitus may also increase or even be induced by the cochlear implantation itself. Cochlear implant candidates should be well informed about these possible consequences before undergoing surgery. LEVEL OF EVIDENCE: 2b Laryngoscope, 126:956-961, 2016

Comparison of Bilateral and Unilateral Cochlear Implantation in Adults A Randomized Clinical Trial

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