Guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL) and the French Society of Audiology (SFA) for Speech-in-Noise Testing in Adults.

OBJECTIVES: This document presents the fundamentals of speech audiometry in noise, general requirements for implementation and criteria for choice among the tests available in French according to the health-professional's needs. MATERIAL AND METHODS: The recommendations are based on a systematic analysis of the literature carried out by a multidisciplinary group of doctors, audiologists and audioprosthetists from all over France. They are graded A, B, C or expert opinion according to decreasing level of scientific evidence. RESULTS: Eight tests of speech audiometry in noise can be used in France. CONCLUSION: To be complete, evaluation of hearing status requires testing understanding of speech in noise. The examination must begin with a minimum of two measurements familiarizing the subject with the test procedure. For initial diagnosis, adaptive procedures establishing the 50% speech reception threshold (SRT50) in noise are to be preferred in order to obtain a rapid and standardized measurement of perception of speech in noise. When the aim is to measure real-life speech comprehension, tests based on sentences, cocktail-party noise and free-field stimulation are to be preferred. Prosthetic gain is evaluated exclusively in free field. This is the only way to evaluate the contribution of binaurality and to measure perception in noise in an environment as close as possible to real life. In order to avoid acoustic interference in free field, at least five loudspeakers should be used, in particular for evaluating the effectiveness of directional microphones, CROS devices enabling sounds picked up in the damaged ear to be rerouted to the functional ear, or bimodal fitting (i.e., when hearing is enabled by two modalities: for example, hearing aid for one ear, cochlear implant for the other).

Guidelines of the French Society of Otorhinolaryngology-Head and Neck Surgery (SFORL) and the French Society of Audiology (SFA) for Speech-in-Noise Testing in Adult [Pré-print]

This document presents the fundamentals of speech audiometry in noise, general requirements for implementation and criteria for choice among the tests available in French according to the health-professional's needs. The recommendations are based on a systematic analysis of the literature carried out by a multidisciplinary group of doctors, audiologists and audioprosthetists from all over France. They are graded A, B, C or expert opinion according to decreasing level of scientific evidence. Eight tests of speech audiometry in noise can be used in France. To be complete, evaluation of hearing status requires testing understanding of speech in noise. The examination must begin with a minimum of two measurements familiarizing the subject with the test procedure. For initial diagnosis, adaptive procedures establishing the 50% speech reception threshold (SRT50) in noise are to be preferred in order to obtain a rapid and standardized measurement of perception of speech in noise. When the aim is to measure real-life speech comprehension, tests based on sentences, cocktail-party noise and free-field stimulation are to be preferred. Prosthetic gain is evaluated exclusively in free field. This is the only way to evaluate the contribution of binaurality and to measure perception in noise in an environment as close as possible to real life. In order to avoid acoustic interference in free field, at least five loudspeakers should be used, in particular for evaluating the effectiveness of directional microphones, CROS devices enabling sounds picked up in the damaged ear to be rerouted to the functional ear, or bimodal fitting (i.e., when hearing is enabled by two modalities: for example, hearing aid for one ear, cochlear implant for the other).

Phosphorylation of GATA4 serine 105 but not serine 261 is required for testosterone production in the male mouse.

BACKGROUND: GATA4 is a transcription factor essential for male sex determination, testicular differentiation during fetal development, and male fertility in the adult. GATA4 exerts part of its function by regulating multiple genes in the steroidogenic enzyme pathway. In spite of these crucial roles, how the activity of this factor is regulated remains unclear. OBJECTIVES: Studies in gonadal cell lines have shown that GATA4 is phosphorylated on at least two serine residues-serine 105 (S105) and serine 261 (S261)-and that this phosphorylation is important for GATA4 activity. The objective of the present study is to characterize the endogenous role of GATA4 S105 and S261 phosphorylation in the mouse testis. MATERIALS AND METHODS: We examined both previously described GATA4 S105A mice and a novel GATA4 S261A knock-in mouse that we generated by CRISPR/Cas9 gene editing. The male phenotype of the mutants was characterized by assessing androgen-dependent organ weights, hormonal profiles, and expression of multiple testicular target genes using standard biochemical and molecular biology techniques. RESULTS: The fecundity of crosses between GATA4 S105A mice was reduced but without a change in sex ratio. The weight of androgen-dependent organs was smaller when compared to wild-type controls. Plasma testosterone levels showed a 70% decrease in adult GATA4 S105A males. This decrease was associated with a reduction in Cyp11a1, Cyp17a1, and Hsd17b3 expression. GATA4 S261A mice were viable and testis morphology appeared normal. Testosterone production and steroidogenic enzyme expression were not altered in GATA4 S261A males. DISCUSSION AND CONCLUSION: Our analysis showed that blocking GATA4 S105 phosphorylation is associated with decreased androgen production in males. In contrast, S261 phosphorylation by itself is dispensable for GATA4 function. These results confirm that endogenous GATA4 action is essential for normal steroid production in males and that this activity requires phosphorylation on at least one serine residue.

Perception in noise with the Digisonic SP cochlear implant: Clinical trial of Saphyr processor's upgraded signal processing.

OBJECTIVES: In 2012, Bergeron et al. presented the outcomes of a study where speech recognition abilities were compared between the four major cochlear implant manufacturers from comparable samples assessed with the same protocols. At this moment, results showed no significant difference in speech perception between devices in quiet and in different noise conditions. But, while most devices appeared only slightly disturbed by the presence of a low to moderate noise level, the Oticon Medical device appeared significantly more sensitive to a degraded environment. In 2013, the signal processing strategy of this device has been upgraded. This study proposes to assess the benefits derived from this upgrade. MATERIALS AND METHODS: The study involves eighteen adults; most were also part of the 2012 study. All were tested before the implementation of the new signal processing strategy, immediately following the implementation of the strategy and after a one-month experience with the strategy. The same speech recognition test and conditions used in the 2012 study were applied, that is the HINT in quiet and in noise at +10, +5 and 0dB signal to noise ratio. Subjective impressions on the upgraded strategy were also gathered. RESULTS: The study evidences similar performance for speech perception in quiet, but significant improvements for speech perception in noise with the new processing strategy compared to the original. Subjective reports confirm this improvement in more challenging conditions. CONCLUSION: The high sensitivity to a degraded environment observed with the original Oticon Medical device has been significantly reduced by the introduction of more efficient noise reduction processing strategies.

Cross-modal reorganization and speech perception in cochlear implant users.

Recent work suggests that once the auditory cortex of deaf persons has been reorganized by cross-modal plasticity, it can no longer respond to signals from a cochlear implant (CI) installed subsequently. To further examine this issue, we compared the evoked potentials involved in the processing of visual stimuli between CI users and hearing controls. The stimuli were concentric circles replaced by a different overlapping shape, inducing a shape transformation, known to activate the ventral visual pathway in human adults. All CI users had their device implanted for >1 year, but obtained different levels of auditory performance following training to establish language comprehension. Seven of the 13 patients showed good capacities for speech recognition with the CI (good performers) while the six others demonstrated poor speech recognition abilities (poor performers). The evoked potentials of all patients showed larger amplitudes, with different distributions of scalp activations between the two groups. The poor performers exhibited broader, anteriorly distributed, high P2 amplitudes over the cortex whereas the good performers showed significantly higher P2 amplitudes over visual occipital areas. These results suggest the existence of a profound cross-modal reorganization in the poor performers and an intramodal reorganization in the good performers. We interpret these data on the basis of enhanced audiovisual coupling as the key to a long-term functional improvement in speech discrimination in CI users.

Long-term follow-up of cochlear implant users with ossified cochlea.

OBJECTIVE: Cochlear implantation surgery in ossified cochlea is a challenge, even for the experienced otologist. Short-term assessments of auditory perception show that implantation in partial or even extensive ossified cochlea could be achieved with varying success, but no long-term follow-up results have been published yet. DESIGN AND METHODS: This paper proposes a retrospective review of eight Nucleus cochlear implant users with ossified cochlea who have been followed on a 12- to 60-month period. MAIN OUTCOME MEASURE: Auditory performances of users are reported at each control on a scale of 100 units divided into 4 skill zones of 25 units based on Erber's proposition, that is, detection, discrimination, identification, and recognition. RESULTS: Three of the eight subjects showed some progression in their auditory performances during the follow-up. The five other subjects showed no long-term progress in their auditory performance. CONCLUSIONS: Open-set comprehension could be achieved with the insertion of 9 to 10 electrodes of the Nucleus device. Auditory performance in users with ossified cochlea seems to be influenced by the same factors as in users with patent cochlea.

Defective p56Lck activity in T cells from an adult patient with idiopathic CD4+ lymphocytopenia.

Idiopathic CD4(+) lymphocytopenia (ICL) is defined by a stable loss of CD4(+) T cells in the absence of any known cause of immune deficiency. This syndrome is still of undetermined origin. It affects adult patients, some of them displaying opportunistic infections similar to HIV-infected subjects. The hypothesis that the cellular immune defect may be due to biochemical failures of the CD3-TCR pathway is investigated here in a patient associating a severe selective CD4(+) lymphocytopenia with an increased CD8(+) T cell count discovered in the course of a cryptococcal meningitidis. A 40% reduction of T cell proliferation to CD3-TCR stimulation is observed only in the CD4(+) subpopulation. The early CD3-induced protein tyrosine phosphorylations are conserved in both CD4(+) and CD8(+) subsets, and the levels of the T cell protein tyrosine kinases p56(Lck), p59(Fyn) and ZAP-70 are normal. However, we find a 50% reduction of p56(Lck) kinase activity in the patient's T cells compared to a healthy control donor. p59(Fyn) activity does not appear to be altered. Nevertheless, we do not find any genetic abnormality of p56(Lck). These results thus suggest that a defect of an unknown protein regulating p56(Lck) activity takes place in this patient's T cells. Taken together, these findings reveal p56(Lck) alteration in ICL and confirm the critical role of this kinase in the maintenance of the peripheral CD4(+) T cell subpopulation.

Subtilase-like pro-protein convertases: from molecular specificity to therapeutic applications.

Limited proteolysis of most large protein precursors is carried out in vivo by the subtilisin-like pro-protein convertases. Many important biological processes such as peptide hormone synthesis, viral protein processing and receptor maturation involve proteolytic processing by these enzymes, making them potential targets for the development of novel therapeutic agents. However, the efficient development of such molecules requires a better understanding of the molecular mechanisms of proteolytic protein processing. Herein, we review the most recent findings on the molecular aspects of subtilisin-like convertase activity, such as the structural analysis of the proteases, the mechanisms of enzyme/substrate specificity, their interaction with other proteins such as 7B2, and the comparative tissue and cellular distribution of the enzymes and their substrates. These data are then used as a background for the review of the known biological functions of subtilisin-like pro-protein convertases, the reported clinical cases involving proteolytic processing defects and, finally, the ongoing development of new therapeutic inhibitor molecules based on this knowledge.

Miniglucagon (glucagon 19-29), a potent and efficient inhibitor of secretagogue-induced insulin release through a Ca2+ pathway.

Using the MIN6 B-cell line, we investigated the hypothesis that miniglucagon, the C-terminal () fragment processed from glucagon and present in pancreatic A cells, modulates insulin release, and we analyzed its cellular mode of action. We show that, at concentrations ranging from 0.01 to 1000 pM, miniglucagon dose-dependently (ID50 = 1 pM) inhibited by 80-100% the insulin release triggered by glucose, glucagon, glucagon-like peptide-1-(7-36) amide (tGLP-1), or glibenclamide, but not that induced by carbachol. Miniglucagon had no significant effects on cellular cAMP levels. The increase in 45Ca2+ uptake induced by depolarizing agents (glucose or extracellular K+), by glucagon, or by the Ca2+channel agonist Bay K-8644 was blocked by miniglucagon at the doses active on insulin release. Electrophysiological experiments indicated that miniglucagon induces membrane hyperpolarization, probably by opening potassium channels, which terminated glucose-induced electrical activity. Pretreatment with pertussis toxin abolished the effects of miniglucagon on insulin release. It is concluded that miniglucagon is a highly potent and efficient inhibitor of insulin release by closing, via hyperpolarization, voltage-dependent Ca2+ channels linked to a pathway involving a pertussis toxin-sensitive G protein.

Leukemic CD3+ LGL share functional properties with their CD8+ CD57+ cell counterpart expanded after BMT.

Leukemic T-LGL (large granular lymphocyte) composed of clonal CD3+ TCR alphabeta+ CD8+ CD57+ cells were compared with oligoclonally CD3+ CD8hi+ CD57- lymphocytes expanded after BMT. Leukemic CD3+ CD8hi+ CD57+ LGL showed several phenotypic differences such as an upregulation of CD16 and adhesion molecules (mainly CD11c, CD58 and CD54), activation markers and an exclusive CD45RA isoform expression. Unstimulated CD3+ CD8+ CD57+ LGL from both leukemic and BMT donors spontaneously developed an ex vivo CTL-like CD3-redirected cytotoxicity but no NK cell activity. Different stimuli (PHA, PMA or rhIL-2) induced similar cytotoxic profiles after a 6-day culture involving a CD3-redirected lysis predominating over a low NK cell activity. However, culture of leukemic LGL with these stimuli allowed either a 2 week persistence (PMA or rhIL-2) of CD8+ CD57+ LGL or their disappearance after 3 days (PHA). Furthermore, leukemic CD8hi+ CD57+ T lymphocytes produced an inhibitor of cytotoxic functions as previously described for BMT recipients' CD8+ CD57+ cells. Thus, despite some phenotypic differences between both cell sources, leukemic CD57+ T-LGL display the same functional characteristics of cytotoxic effector and immunoregulatory T cells as CD8+ CD57+ T cells from BMT recipients which might represent their normal counterpart.

[Deficiency of the CD3-TCR signal pathway in three patients with idiopathic CD4+ lymphocytopenia]. / Anomalies de la voie de signalisation CD3-TCR chez trois patients atteints de lymphopenie CD4+ idiopathique.

Idiopathic CD4+ lymphocytopenia (ICL) is a rare syndrome affecting adults and defined by a stable loss of CD4+ T cells in the absence of any known cause of immune deficiency. Defective T-cell proliferations to mitogens and antigens have been described in some of such patients displaying clinical signs of immune deficiency such as opportunistic infections. We investigated here the hypothesis that T-cell depletion and dysfunction could be due to biochemical defects of the CD3-TCR pathway in CD4+ and/or CD8+ subsets from three patients with severe stable ICL (below 150 CD4+ T cells/microliter) and opportunistic infections. Patient 1 had a general T lymphocytopenia, whereas patients 2 and 3 displayed a selective loss of CD4+ T cells. We observed in all patients a major reduction of the proliferative response to CD3-TCR stimulation that affected only the depleted T-cell subpopulation. Moreover, in two cases, impaired early biochemical events of the CD3-TCR pathway were detected. In patient 1 and 3, we found a defect (of distinct intensity) of CD3-induced protein tyrosine phosphorylation in CD4+ cells compared to control cells, whereas this process was normally induced in CD4+ T cells from patient 2. Taken together, this study reveals that the heterogeneity of the ICL syndrome was situated at the cellular level, and involved in two cases abnormalities of transducing molecules of the CD3-TCR pathway.

Molecular cloning and tissue distribution of rat sarcosine dehydrogenase.

Sarcosine dehydrogenase (SarDH) is a mitochondrial flavoenzyme involved in the oxidative degradation of choline to glycine. The absence of SarDH activity in humans is genetically transmitted and is the cause of an amino acid metabolism disorder called sarcosinemia. Tryptic fragments of the purified enzyme from rat liver were subjected to Edman degradation and the sequences obtained were used to clone the cDNA encoding the full length protein. The deduced amino acid sequence of SarDH shares an overall similarity of 47% with dimethylglycine dehydrogenase (Me2GlyDH), another flavoenzyme involved in the mitochondrial choline catabolism with a similar FAD-binding domain. Covalent binding of FAD to SarDH was demonstrated by the observation of strong fluorescence at 530 nm under excitation at 450 nm of the enzyme immunoprecipitated under denaturing conditions from liver extracts. The localization of SarDH immunoreactivity in the mitochondrial matrix was confirmed by Western-blot analysis of purified mitochondrial fractions. Finally, the tissue distribution of SarDH was investigated by Northern-blot analysis of total RNA and Western-blot analysis of total protein from several rat tissues. A strong expression in the liver, but also in the lung, pancreas, kidney, thymus, and oviduct was observed. We therefore suggest that the enzymes of the choline catabolism pathway are important also for metabolism in nonhepatic tissues.

CD8hi+CD57+ T lymphocytes are enriched in antigen-specific T cells capable of down-modulating cytotoxic activity.

Major expansions of CD8hi+CD57+ T lymphocytes frequently occur during human immunodeficiency virus (HIV) infection and after transplantation. To investigate mechanisms of such cell expansion, we compared the activation and functional status of CD8hi+CD57+ and CD57-peripheral blood lymphocytes (PBL) from normal, bone marrow transplantation (BMT) and HIV+ donors. The CD8hi+CD57+ PBL from BMT and HIV+ donors preferentially displayed CD38 and HLA-DR activation markers without correlation between CD8hi+CD57+ percentages and HIV load, the CD45RA+ isoform in all ex vivo conditions but acquired CD45RO after in vitro expansion, CD11b and CD11c in BMT and HIV+ donors but decreased expression of CD62-L, VLA-2 and VLA-6. The CD8hi+CD57+ cells were positive for perforin and granzyme B and spontaneously mediated cytolytic activity in a CD3-redirected assay. In contrast the inhibitor of cytolytic functions (ICF) produced by CD8hi+CD57+ cells down-modulated the CD3-redirected cytolytic activity but only at low levels of CD3 cross-linking. While CD3-triggering induced a low, if any, short-term proliferation of CD8+CD57+ cells, this subset could be amplified after long-term stimulation either with mitogens or with HIV antigens, thereby enriched in HIV-specific T cells producing tumor necrosis factor-alpha. Altogether these data suggest that CD8hi+CD57+ cells represent a terminal differentiation state of activated effector cytotoxic T lymphocytes which are enriched in antigen-specific T cells and down-modulate their own cytolytic potential, thus participating in a negative control of effector cell functions during persistent viral infections or transplantations.

Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants.

A model of auditory performance and a model of ganglion cell survival in postlinguistically deafened adult cochlear implant users are suggested to describe the effects of aetiology, duration of deafness, age at implantation, age at onset of deafness, and duration of implant use. The models were compared with published data and a composite data set including 808 implant users. Qualitative agreement with the model of auditory performance was found. Duration of deafness had a strong negative effect on performance. Age at implantation had a slight negative effect on performance, increasing after age 60 years. Age at onset of deafness had little effect on performance up to age 60. Duration of implant use had a positive effect on performance. Aetiology had a relatively weak effect on performance.

The neuroendocrine precursor 7B2 is a sulfated protein proteolytically processed by a ubiquitous furin-like convertase.

The neuroendocrine granule-associated protein 7B2, unlike many other neuroendocrine precursor proteins stored in secretory granules, carries in its primary structure the Arg-Xaa-Arg/Lys-Arg processing site usually found in constitutively secreted precursor proteins and recognized by the ubiquitously expressed convertase, furin. pro7B2 (30 kDa), when expressed in endocrine (AtT-20, PC12, and GH4C1) or non-endocrine (Ltk-) cell lines using recombinant vaccinia viruses, was converted to a 23-kDa form. Mutation of the P4 Arg to Gly completely prevented this conversion. When excess pro7B2 was coexpressed with the pro-protein convertases PC1, PC2, or furin, only furin could induce complete processing. In addition, coexpression of pro7B2 in LoVo cells, which are devoid of endogenous furin activity, with each one of the three convertases, showed that only furin was able to induce processing of this precursor. pro7B2 processing in AtT-20 was completely abolished when protein transport into Golgi compartments was blocked by cell incubation at either 15 or 37 degrees C in the presence of monensin or brefeldin A. Furthermore, pulse-chase experiments in the presence of Na2[35S]SO4 showed that pro7B2 is Tyr-sulfated in the trans-Golgi network before it is processed. These results demonstrate that pro7B2 is first processed by a furin-like enzyme within the trans-Golgi network into a 23-kDa form that is then sequestered into secretory granules.