Fluticasone propionate suppresses the SARS-CoV-2 induced increase in respiratory epithelial permeability in vitro.

BACKGROUND: Disruption of the nasal epithelial barrier is believed to play a role in Coronavirus Disease-2019 (COVID-19) outcomes. Fluticasone propionate has been shown to restore the nasal epithelial barrier in allergic rhinitis to the level of healthy controls. The therapeutic potential of nasal steroid sprays in COVID-19 has recently been reported. However, further insight into the mode of action is warranted. OBJECTIVES: To explore the in vitro mechanisms of the preventive potential of fluticasone propionate in SARS-CoV-2 infection. METHODS: Human air liquid interface cultures of Calu-3 cells and primary nasal epithelial cells isolated from healthy donors were used to investigate the preventive effect of fluticasone propionate on SARS-CoV-2 induced barrier disruption, virus replication and ACE2 expression. RESULTS: 48 hours pre-treatment with fluticasone propionate prevented the SARS-CoV-2 induced increase in fluorescein isothiocyanate-dextran 4 kDa permeability and reduced infection with SARS-CoV-2. Pre-treatment with fluticasone propionate also decreased ACE2 expression in SARS-CoV-2 infected Calu-3 cells. CONCLUSION: Fluticasone propionate pre-treatment prevented SARS-CoV-2 increased epithelial permeability, reduced ACE2 expression and SARS-CoV-2 infection, underscoring the therapeutic potential of fluticasone propionate in the context of COVID-19.

Is cochlear implantation an effective treatment for Menière's disease?

OBJECTIVES: describe the results of a retrospective study of cochlear implantation (CI) in seven subjects with Menière's disease. METHODOLOGY: The subjects received either the Nucleus CI24RE(CA)/CI512 or the Advanced Bionics HiRes90K CI systems which use the ACE, MP3000, or HiRes S Fidelity 120 coding strategies. The audiometric measures included monosyllabic word lists (NVA) in quiet at 65 dB SPL and sentences in noise (LIST) at +10 dB SNR. The quality of life after implantation was assessed by means of the Nijmegen Cochlear Implant Questionnaire (NCIQ). RESULTS: After CI, the hearing of all subjects improved significantly (p < 0.001) as did their speech recognition (p = 0.018). Speech recognition in noise showed a mean improvement of 47%. The results were less clear for the treatment of vertigo associated with Menière's, as some patients continued to have vestibular attacks after implantation. On the NCIQ, subjects reported a mean quality of life after CI of 48.3%. CONCLUSIONS: This study clearly demonstrates that cochlear implantation is an adequate treatment of speech perception for subjects with Menière's disease who go on to develop bilateral severe to profound sensorineural hearing loss.

Cochlear implantation in posttraumatic bilateral temporal bone fracture.

Temporal bone (TB) fractures can cause loss of audiovestibular function. Four cases of profound hearing impairment following bilateral TB fracture are presented in this report. All patients received a cochlear implant. All 4 patients became regular users of their implants. None of the patients experienced facial nerve stimulation. Implant-aided audiometry demonstrated a hearing threshold of 28 dB HL. The performance in speech understanding was comparable to standard postlingual adult patients implanted. We believe that cochlear implantation in patients suffering from profound sensorineural hearing losses secondary to TB fractures can be an effective tool for rehabilitation.

[Cyclotriazadisulfonamides as new and unique HIV entry inhibitors]. / Cyclotriazadisulfonamides als nieuwe en unieke HIV-entry inhibitoren.

In order to infect a target cell, the HIV envelope glycoprotein gp120 has to interact with the CD4 receptor, which serves as the primary virus receptor. For most HIV strains, the successful infection of their target cells is mainly dependent on the expression of the CD4 surface molecule which can be considered as an ideal target with multiple windows of opportunity for therapeutic intervention. Therefore, drugs that interfere with the CD4 receptor, and thus inhibit viral entry, may be promising agents for the treatment of AIDS. Here we describe the discovery and characterization of the CD4-targeted HIV entry inhibitors cyclotriazadisulfonamides. They repesent a novel class of small molecule antiviral agents with an unique mode of action. The lead compound, CADA, specifically interferes with cellular CD4 receptor expression and is active against a wide variety of HIV strains at submicromolar levels when evaluated in different cell-types such as T cells, monocytes and dendritic cells. Moreover, a strict correlation has been demonstrated between anti-HIV activity and CD4 down-modulation of about 20 different CADA analogs. In addition, CADA acted synergistically in combination with other FDA-approved anti-HIV drugs. The broad spectrum antiviral activity of CADA against several different subtypes of HIV supports the possible application of this compound as a microbicide. Finally, the development of fluorescent CADA analogs made it feasible to study receptor and its down-modulator simultaneously. These CADA-compounds with reversible CD4 down-modulating potency will be valuable tools in further studies on receptor modulation, and in deciphering the process that plays a role during the complicated interactions between HIV-gp120 and the cellular membrane, which ultimately will lead to a more efficient treatment of HIV-infections.

Phase-shift tinnitus treatment: an open prospective clinical trial.

We report on a novel treatment for tinnitus using phase-shift pure tone sound treatment in patients with predominantly pure tone tinnitus. Thirty-five patients with pure tone tinnitus unresponsive to all previous treatment were enrolled in the study. All patients were treated three times in one week. If the patient noticed an improvement, the therapy was continued for six weeks with a home device customised to their specific treatment frequency. Twenty-one of the 35 patients (60%) responded positively to the initial therapy sessions. Tinnitus was assessed before treatment, after three in-office Tinnitus Phase-Out System therapy sessions, and after six weeks of home use of the Patient Treatment Device. The assessment instruments were a VAS loudness scale and the quality of life Tinnitus Questionnaire. Significant tinnitus reduction was obtained on VAS after three office Tinnitus Phase-Out System therapy sessions (before treatment: mean VAS = 6.4; after three therapy sessions: mean VAS = 4.9; p = 0.042) and after six weeks of home use of the Patient Treatment Device (mean VAS = 4.9; p = 0.005). When analysing the mean TQ score over treatment, there was a significant improvement in total score from pretreatment (mean TQ score = 41.9) to six weeks after home use of the Patient Treatment Device use (mean TQ score = 36.4) (p = 0.003). In view of the results obtained, the Phase-Out Treatment for tinnitus may provide the majority of patients with a significant improvement in their symptoms. Further evaluation, comparing this specific Phase-Out Treatment with more general noise stimulation treatment, will further specify the indications for this treatment option.

Tinnitus: a multidisciplinary clinical approach.

This article provides a clinical step-by-step approach for assessing a patient with tinnitus as primary complaint. The medical diagnosis of the disease provoking the tinnitus has to be made first in a comprehensive evaluation, including imaging. The psycho-acoustic characteristics and the influence on health-related quality of life is a compulsory complementary assessment to establish a complete picture of the patient.

Good speech recognition and quality-of-life scores after cochlear implantation in patients with DFNA9.

OBJECTIVE: To compare audiometric and quality-of-life results in DFNA 9 patients who received a cochlear implant with cochlear implant patients with adult-onset progressive sensorineural hearing loss. STUDY DESIGN: Prospective comparative design; results were collected cross-sectionally. SETTING: Tertiary referral center. PATIENTS: Eleven DFNA 9 patients were included in the study as well as a comparative group of 39 post-lingually deafened cochlear implant subjects with adult-onset progressive sensorineural hearing loss. INTERVENTIONS: All patients received a cochlear implant. Subjects were implanted with either the Nucleus 24 M/RCS or Med-el Combi 40+ cochlear implant systems implementing the SPEAK, ACE, or CIS+ coding strategies. MEAN OUTCOME MEASURES: Speech recognition was determined by means of phonetically balanced monosyllabic word lists. The Hearing Handicap Inventory for Adults, the Glasgow Benefit Inventory, and the Scale for the Prediction of Hearing Disability in Sensorineural Hearing Loss were used to quantify the quality of life. RESULTS: The results show that the speech perception and the quality of life of the DFNA 9 patients do not differ significantly from the control group (p=0.179; p=0.56). CONCLUSION: In spite of the fact that DFNA 9 is a disease that is known to involve cochlear dendrites, cochlear implantation is a good option for treatment of deafness in DFNA 9.

The protective effect of IFN-gamma in experimental autoimmune diseases: a central role of mycobacterial adjuvant-induced myelopoiesis.

The study of animal models for organ-specific autoimmune disease contributes to our understanding of human diseases such as multiple sclerosis and rheumatoid arthritis. Although experimental autoimmune diseases develop spontaneously in certain strains of mice, others need to be induced by administration of organ-specific autoantigen, often together with complete Freund's adjuvant (CFA), containing heat-killed mycobacteria. In the two types of models, the role of endogenous interferon-gamma (IFN-gamma) has extensively been investigated by using neutralizing anti-IFN-gamma antibodies and by employing mice genetically deficient in IFN-gamma or its receptor. In these studies disease-promoting as well as disease-protective roles of endogenous IFN-gamma have been described. Remarkably, in most models that rely on the use of CFA, there is abundant evidence for a protective role. Here, we review evidence that this role derives from an inhibitory effect of IFN-gamma on myelopoiesis elicited by the killed mycobacteria. These findings explain the bimodal role of IFN-gamma in different models of autoimmune disease and raise questions regarding the clinical relevance of these models.

The effects of NO synthase inhibitors on murine collagen-induced arthritis do not support a role of NO in the protective effect of IFN-gamma.

DBA/1 mice deficient in expressing the interferon-gamma (IFN-gamma) membrane receptor (IFN-gammaR KO mice) are more susceptible to collagen-induced arthritis (CIA) than wild-type mice, indicating that endogenous IFN-gamma plays a protective role in the pathogenesis of CIA. In IFN-gammaR KO mice, nitric oxide (NO) production during CIA is impaired. Because NO is known to exert immunosuppressive and anti-inflammatory effects in certain model systems, the protective effect of IFN-gamma might be mediated by NO. Here, we tested in wild-type mice whether inhibition of NO production by metabolic inhibitors, aminoguanidine (AG) and L-N-(1-iminoethyl)lysine (L-NIL), could mimic the ablation of the IFN-gamma receptor. A high-dose regimen of AG supplied in the drinking water inhibited NO production, disease development, and anticollagen antibody production but was also associated with transient body weight loss. At a dose and time regimen that still inhibited NO production but did not cause body weight loss, AG failed to affect disease scores. Treatment with L-NIL, which more specifically than AG affects inducible NO production, caused a slight increase in anticollagen antibody production although not significantly affecting disease occurrence. These data indicate that the diminished capacity of the IFN-gammaR KO mice to produce NO following immunization with collagen is unlikely to account for their higher susceptibility to CIA.

Cochlear implantation: a bionic system to restore hearing in severely hearing impaired patients.

CI replaces and functionally bypasses the inner haircells of the cochlea. Candidate selection is not merely based on non-aided auditory thresholds, but aided speech recognition tests in quite and in noise after a rehabilitation period may be decisive, besides a comprehensive selection process including general health, imaging, learning and cognitive skills, supportive aspect of the environment. The vast majority of severely or profoundly hearing impaired persons can benefit from CI. CI restores hearing of adults to a level allowing normal conversation, using the telephone and even understanding in a limited amount of background noise. Congenitally severely or profoundly hearing impaired children implanted before the age of 2 years, will outperform patients operated at a later age, allowing to follow mainstream education. CI is not just a technique, but the driving force behind an elaborate care-programme for the severely hearing impaired patient.

Comparison between NRT-based MAPs and behaviourally measured MAPs at different stimulation rates--a multicentre investigation.

Seventeen adult subjects participated in a multicentre trial to compare the performance between an NRT-based MAP and their behavioural MAP. The NRT-based MAP was made using a correction factor to predict T/C levels, calculated from the difference between the ECAP threshold ('T-NRT') and the measured T/C levels at electrode 10, as described by Brown et al. (2000). A secondary aim was to compare T/C levels in behavioural MAPs at different stimulation rates with the predicted T/C levels in NRT-based MAPs. Performance with both MAPs was evaluated using CNC words and sentences. Variations in the T/C levels between all MAPs were found, although results of the speech discrimination tests demonstrated no statistically significant difference between behavioural and NRT-based MAPs.

Music perception in electric acoustic stimulation users as assessed by the Mu.S.I.C. test.

AIMS: This study compared the music perception abilities of 13 electric acoustic stimulation (EAS) users with two control groups: unilateral cochlear implant (CI) users and normal-hearing (NH) listeners. METHODS: Groups were matched according to age and musical experience before hearing loss (HL) and tested using the Musical Sounds in Cochlear Implants (Mu.S.I.C.) test. RESULTS: No difference was found on rhythm perception, chord discrimination, dissonance rating, and emotion rating subtest performance between groups. Mean frequency discrimination scores were significantly better in EAS participants than in CI participants and not significantly worse than in NH participants. However, the EAS and CI groups scored similarly (significantly worse than NH participants) on both instrument detection and identification. Results for EAS participants were not significantly worse when the hearing aid component was removed. Frequency of listening to music before HL was negatively correlated with EAS participants' frequency discrimination scores, though singing and playing an instrument appeared to have no effect. EAS participants who indicated many reasons for listening to music and who listen to many genres after implantation scored higher on instrument detection and instrument identification. Better results on these two subtests were correlated with EAS participants' better postoperative auditory thresholds at 250 and 500 Hz. CONCLUSIONS: Though EAS participants performed better on music perception testing (though not timbre-based tasks) than CI participants, their scores did not reach the level of NH participants. This indicates that acoustic hearing in the low frequencies is helpful for music perception, though not the only important factor.

Mac-1(+) myelopoiesis induced by CFA: a clue to the paradoxical effects of IFN-gamma in autoimmune disease models.

The mechanisms accounting for the protective role of endogenous interferon gamma (IFN-gamma) in certain murine autoimmune disease models, versus a disease-promoting role in others, have remained elusive. The protective effect of IFN-gamma might be unique to models that rely on the use of complete Freund's adjuvant (CFA) and whose pathogenesis is predominantly driven by delayed-type hypersensitivity. In these models, IFN-gamma counteracts disease development by inhibiting CFA-induced proliferation of a pathogenically important Mac-1(+) cell population(s). This calls into question our usual conceptualization of the balance between innate and specific immunity in these models, as well as their clinical relevance, particularly when the role of IFN-gamma or related cytokines is considered.

Accelerated collagen-induced arthritis in IFN-gamma receptor-deficient mice.

Collagen-induced arthritis (CIA) is a model for rheumatoid arthritis. Here, we describe experiments showing that IFN-gamma receptor knockout (IFN-gammaR alpha KO) mice of the DBA/1 strain develop CIA more readily than their wild-type counterparts. Symptoms of disease started 10 days earlier and the cumulative incidence of arthritis was significantly higher in the mutant mice than in wild-type mice. Similarly, accelerated onset of the disease was also found in wild-type DBA/1 mice treated with neutralizing mAbs against IFN-gamma. Histologic examination of the joints revealed a massive infiltration of the synovium with mononuclear cells and neutrophils, hyperplasia, and severe pannus formation in IFN-gammaR alpha KO mice when such inflammatory lesions were not yet detectable in wild-type mice. Serum levels of anti-collagen type II Abs, including total IgG and IgM, as well as IgG1, IgG2a, and IgG2b isotypes were found to be lower in the mutant mice. IL-2 and IL-4 remained undetectable in sera of both groups of mice, but did appear in the circulation after anti-CD3 Ab challenge. Significantly higher IL-2 and lower IL-4 serum levels were found in anti-CD3-challenged IFN-gammaR alpha KO mice than in wild-type counterparts, both at an early and at a later stage of the disease. These observations indicate that endogenous IFN-gamma counteracts development of collagen-induced arthritis and suggest that IFN-gamma does so by up-regulating IL-4 production and/or down-regulating IL-2 production. The data are in line with the concept of a pathogenic role of Th1-type cellular immunity in CIA in spite of a decreased Ab response to collagen type II.

Sensitivity of human immunodeficiency virus to bicyclam derivatives is influenced by the three-dimensional structure of gp120.

The bicyclams are a new class of anti-human immunodeficiency virus (anti-HIV) compounds targeted at viral entry. From marker rescue experiments, it appears that the envelope gp120 glycoprotein plays an important role in the anti-HIV activity of the bicyclams. Bicyclam-resistant strains contain a number of amino acid changes scattered over the V2 to V5 region of gp120. Experiments aimed at estimating the relative importance of particular amino acid changes with regard to the overall resistance pattern are described. The sequences of some partially bicyclam-resistant virus strains, obtained during the resistance development process, were analyzed, and the corresponding 50% effective concentrations were determined. Selected mutations observed in bicyclam-resistant strains were introduced in the wild-type background by site-directed mutagenesis. In addition, some amino acids were back-mutated to their wild-type counterparts in an otherwise JM3100-resistant strain. The sensitivities of these mutant viruses to bicyclams were determined. Construction of chimeric viruses, carrying the V3 loop of JM3100-resistant virus in a wild-type HIV type 1 HXB2 background, enabled us to investigate the importance of the mutations in the V3 loop of JM3100-resistant virus. From the results described in the report, it can be concluded that single amino acid substitutions do not influence the observed resistance to JM3100. Also, the mutations in the V3 loop are not sufficient to engender even a partially resistant phenotype. We postulate that the overall conformation of gp120 determines the degree of sensitivity or resistance of HIV strains to bicyclams.

Anti-IL-12 antibody prevents the development and progression of collagen-induced arthritis in IFN-gamma receptor-deficient mice.

In several models of inflammation, including collagen-induced arthritis (CIA), the disease-promoting effect of IL-12 has been attributed to its well-known ability to produce IFN-gamma. However, IFN-gamma receptor knockout (IFN-gammaR KO) mice of the DBA/1 strain have been reported to be more susceptible to CIA than corresponding wild-type mice, indicating the existence of an IFN-gamma-mediated protective pathway in this model. In the present study the development of CIA was found to be completely prevented by pretreatment with a neutralizing anti-IL-12 antibody, not only in wild-type, but significantly also in IFN-gammaR KO mice. In both strains of mice, the protective effect of anti-IL-12 was associated with lower production of anti-collagen type II antibodies. In vivo stimulation with anti-CD3 antibody in arthritic IFN-gammaR KO mice resulted in production of higher levels of circulating IFN-gamma, TNF and IL-2 than in corresponding control mice that had not received the arthritis-inducing immunization. This was not the case in arthritis-developing wild-type mice. Furthermore, the protective effect of anti-IL-12 antibody in mutant, but not in wild-type mice, was associated with lower circulating IFN-gamma, TNF and IL-2 and higher IL-4 and IL-5 cytokine levels following an anti-CD3 challenge. The data indicate that IL-12 promotes the development of arthritis independently of its ability to induce or favor production of IFN-gamma. In fact, any IFN-gamma produced in the course of the disease process rather exerts a protective effect. Furthermore, our study suggests that, in the absence of a functional IFN-gamma system, endogenous IL-12 exerts its disease-promoting effect by favoring production of other Th1-associated cytokines (IL-2 and TNF), by inhibiting development of IL-4- and IL-5-producing T cells and by stimulating production of anti-collagen autoantibodies.

Interpretation of pure-tone thresholds in sensorineural hearing loss (SNHL): a review of measurement variability and age-specific references.

When assessing a patient with a sensorineural hearing impairment, the most simple and most widely available technical investigation is pure-tone audiometry. Although it is a subjective measure, the test is very reliable if the patient is cooperative. In this paper we review standards and test-retest reliability for pure-tone audiometry. A pure-tone threshold measurement at a single frequency has a chance of 90% to be repeated between -10 dB and +10 dB compared to the first measurement, assuming no real change in hearing thresholds has occurred. It is also of great importance to use correct gender- and age-specific reference values when interpreting pure-tone threshold measurements. Several large-scale epidemiological studies have been conducted during recent years, and have provided us with reliable gender- and age-specific references. A method to take into account the age-related deterioration is presented. In this method, Z-score audiograms represent traditional thresholds in an age- and gender-independent way. At each frequency, the Z-score value is the number of standard deviation units that the threshold differs from the median value for the otologically normal population (ISO 7029).

Speech recognition tests in sensorineural hearing loss.

The ability to understand speech must be considered the most important measurable aspect of human auditory function. Due to the innovative developments in hearing aids and cochlear implants, there has been a renewed interest in speech recognition testing. During recent years, the start of several multi-centre studies have increased the urge to come to some consensus on the use of different speech materials. In this article a global overview of existing types of speech material in Dutch will be given. For each type, there is a reference to similar speech audiometric tests in French, English and German.

Enhanced autoimmune arthritis in IFN-gamma receptor-deficient mice is conditioned by mycobacteria in Freund's adjuvant and by increased expansion of Mac-1+ myeloid cells.

Induction of experimental autoimmune diseases often relies on immunization with the organ-specific autoantigens in CFA, which contains heat-killed mycobacteria. In several of these models, including collagen-induced arthritis, endogenous IFN-gamma acts as a disease-limiting factor in the pathogenesis of the disease. Here we show that in collagen-induced arthritis the protective effect of IFN-gamma depends on the presence of mycobacteria in the adjuvant. Omission of mycobacteria inverts the role of endogenous IFN-gamma to a disease-promoting factor. Thus, the mycobacterial component of CFA opens a pathway by which endogenous IFN-gamma exerts a protective effect that supersedes its otherwise disease-promoting effect. Extramedullary hemopoiesis and expansion of the Mac-1+ cell population accompanied the accelerated and more severe disease course in the IFN-gamma receptor knockout mice immunized with CFA. Treatment of such mice with Abs against the myelopoietic cytokines IL-6 or IL-12 inhibited both disease development and the expansion of the Mac-1+ population. We postulate that mycobacteria in CFA stimulate the expansion of the Mac-1+ cell population by a hemopoietic process that is restrained by endogenous IFN-gamma. These results have important implications for the validity of animal models of autoimmunity to study the pathogenesis and to evaluate cytokine-based therapy of autoimmune diseases.

The molecular target of bicyclams, potent inhibitors of human immunodeficiency virus replication.

Bicyclams are a novel class of antiviral compounds which act as potent and selective inhibitors of the replication of human immunodeficiency virus type 1 (HIV-1) and HIV-2. They block an early step in the viral life cycle following adsorption to the CD4 receptor and preceding reverse transcription. To identify the molecular target of these compounds, we genetically analyzed variants of the HIV-1 molecular clone NL4-3, which developed resistance against two structurally related bicyclams, JM2763 and the more potent SID791. The resistant strains were obtained after long-term passaging in MT-4 cells in the presence of progressively increasing compound concentrations. Recombinants between selected genes of the resistant strains and the parental NL4-3 provirus were generated by adapting the marker rescue technique to MT-4 cells. The bicyclam-resistant phenotype was rescued by transferring the envelope gp120 gene of bicyclam-resistant virus into the NL4-3 parental genetic background. In the gp120 genes of the resistant strains, we identified several mutations leading to amino acid substitutions in the V3 loop. Furthermore, two substitutions of highly conserved amino acids in close proximity to the disulfide bridges of the V3 and V4 loops were found in both SID791- and JM2763-resistant strains. Additional mutations in regions encoding V3, C4, V5, and C5 were present in SID791-resistant viruses. Recombination experiments with overlapping parts of the envelope gene indicated that most, if not all, of the mutations were necessary to develop the fully SID791 resistant phenotype. The mutations in the C-terminal part of gp120 downstream of the V3 loop sequence conferred partial resistance to JM2763 but did not significantly decrease susceptibility to SID791. The genetic data and the biological properties of the resistant viruses point to inhibition of entry and fusion as the mode of action of the HIV-inhibitory bicyclams. A possible mechanism of binding of bicyclams to gp120 leading to inhibition of unfolding of gp120 and its shedding from the gp41 fusion domain is discussed.