O--(−)-catechin, TMCG) and dimiristoylphosphatidyl-ethanolamine (DMPE) membranes using an array of biophysical techniques which include differential scanning calorimetry, X-ray diffraction, infrared spectroscopy, atomic force microscopy, and molecular dynamics simulations. We found that TMCG incorporate into DMPE bilayers perturbing the thermotropic transition from the gel to the fluid state forming enriched domains which separated into different gel phases. TMCG does not influence the overall bilayer assembly of phosphatidylethanolamine systems but it manages to influence the interfacial region of the membrane and slightly decrease the interlamellar repeat distance of the bilayer. TMCG seems to be located in the interior of the phosphatidylethanolamine bilayer with the methoxy groups being in the deepest position and some portion of the molecule interacting with the water interface. We believe that the reported interactions are significant not only from the point of view of the known antitumoral effect of TMCG, but also might contribute to understanding the basic molecular mechanism of the biological effects of the catechins found at the membrane level.Green tea catechins exhibit high diversity of biological effects including antioncogenic properties, and there is enormous interest in their potential use in the treatment of a number of pathologies. It is recognized that the mechanism underlying the activity of catechins relay in part in processes related to the membrane, and many studies revealed that the ability of catechins to interact with lipids plays a probably necessary role in their mechanism of action. We present in this work the characterization of the interaction between an antitumoral synthetically modified catechin (3- The presence of bioactive catechins in green tea has been implicated in the protection against various pathological conditions and the scientific interest in these polyphenols as therapeutic agents is rapidly increasing ,2,3. CatThere is evidence confirming that green tea catechins show strong anticancer effects ,11 and tDespite the high number of studies reporting biological effects of catechins, the underlying molecular mechanism is not completely elucidated. It is broadly recognized that the biological activity of catechins affects activities present in the membrane like signal transduction  and it hConsidering all the above evidence, the interaction between catechins and membranes is emerging as an interesting field of investigation. It is known that catechins decrease membrane fluidity  and causThe effects of TMCG on membranes was studied using model lipid membranes composed by dimiristoylphosphatidylethanolamine (DMPE). We used DSC to characterize the influence of the catechin on the thermotropic transition of DMPE and used X-ray diffraction, infrared spectroscopy, and atomic force microscopy to study the effect of TMCG on the structure and organization of the phospholipid. Finally, molecular dynamics simulation was used to determine the location and interaction of TMCG with the phosphatidylethanolamine bilayer.β gel phase to the Lα liquid crystalline or fluid phase. When TMCG is not present, pure DMPE shows a transition temperature (Tc) at 49 °C and an enthalpy change of 6 kcal/mol, in accordance with earlier findings [In findings ,30. The findings  and for findings .We examined the structural characteristics of DMPE/TMCG system using Small Angle X-ray Diffraction (SAXD). Phospholipids which are organized in multilamellar structures produce reflections with distances relating as 1:1/2:1/3:1/4… . Figure β gel phase. After the transition, pure DMPE displays a broad diffuse reflection distinctive of the liquid crystalline Lα phase [β phase.The packing symmetry of the phosphatidylethanolamine acyl chains can be deduced using X-ray diffraction in the wide angle region WAXD, . Before Lα phase ,35. The We have previously found that, in dipalmitoylphosphatidylcholine systems, the complex formed at low temperatures in the presence of a high TMCG molar ratio had the characteristics of an interdigitated phase . At diffWith the information obtained from DSC and X-ray diffraction we made partial phase diagrams for the DMPE component in combination with TMCG. −1 [−1 at the cost of the component centered at 1742 cm−1 [−1 correspond to hydrated carbonyl groups (hydrogen-bonded) while that centered at 1742 cm−1 corresponds to dehydrated carbonyl groups (non-hydrogen-bonded) [−1.We used infrared spectroscopy to investigate the effects of TMCG on the interfacial region of DMPE bilayers. The infrared absorption band corresponding to the interfacial carbonyl groups of phosphatidylethanolamines experiences alterations when the phospholipid undergoes the transition from the gel phase to the fluid phase . When TM−1 . The tra742 cm−1 . These d-bonded) ,42. Figu−1. Gaussian-Lorentzian functions were used and we determined the areas corresponding to the different components. We present in −1) versus temperature for the different mixtures. For pure DMPE, the percentage of hydrated carbonyls present in the gel phase (near 55%) is lower than that found in the fluid phase (near 75%). Previous studies indicated that this difference corresponds to the higher number of hydrogen bonds established by the carbonyl groups in the liquid crystalline phase accounting for the increase in hydration of the water interface which occurs in this phase [We used curve fitting procedures to fit the spectra obtained from pure DMPE and mixtures with TMCG to three components centered at 1742, 1728, and 1714 cmis phase . The trais phase .To check the topology of DMPE/TMCG systems, supported bilayers were studied through the use of AFM . Figure z-axis which is normal to the DMPE bilayer. TMCG was originally situated in the water phase and, during the simulation, TMCG was able to interact with the bilayer. The precise location of the different components is presented in Molecular dynamics simulations were carried out to study the location of TMCG in the DMPE bilayer. We first analyzed the density profiles of the different components of the system along the Theses finding might be important to understand the mechanism for the activation or TMCG prodrug in melanoma , in thisDimyristoylphosphatidylethanolamine (DMPE) was obtained from Avanti Polar Lipids Inc. . (−)-Catechin and 3,4,5-trimethoxybenzoyl chloride were from Sigma Chemical Co., Madrid, Spain). Purified water was deionized in a Milli-Q equipment from Millipore , and filtered through 0.24 μm filters prior to use. All other reagents were of the highest purity available. The synthesis of TMCG was achieved from the commercially available catechin, following a process already described . Solutio−1 phospholpid were studied using a MicroCalMC2 calorimeter  at a heating rate of 60 °C·h−1. The onset and completion temperatures obtained from the heating scans were used to construct the partial temperature-composition phase diagram.Convenient chloroform/methanol (1:1) solutions of DMPE and TMCG were mixed and the solvent was evaporated to dryness (nitrogen stream and 3 h at high vacuum). After the addition of 2 mL of buffer  vesicles were formed by vortexing at temperature well above the gel to fluid transition temperature of the dehydrated DMPE. Samples containing 1 mg·mL−1 and 0.20–0.29 Å−1 respectively as already defined [We used Nickel-filtered Cu Kα X-rays generated by a Philips PW3830 X-ray Generator operating at 50 kV and 30 mA, and a modified Kratky camera  equipped with two coupled linear position sensitive detectors  monitoring the s-ranges  between 0.0075–0.7 Å defined . We cent2O buffer and arranged between CaF2 windows (25 mm × 2 mm) using 25 μm Teflon spacers and a Symta cell mount. We used a Nicolet 6700 Fourier-transform infrared spectrometer (FT-IR) . 256 interferograms with a nominal resolution of 2 cm−1 were collected every 2 °C with 5 min temperature equilibration employing a Peltier device . The subtraction of buffer spectra was carried out using Omnic or Grams software.Samples containing 15 mg DMPE and the proper amount of TMCG were prepared as described above in DDried DMPE lipids (with and without TMCG) were resuspended in 100 μL buffer solution and vesicles were made by vortexing at 65 °C. Around 200 nm diameter liposomes were formed by mechanical extrusion at 60 °C through a Whatman nuclepore Track-Etched polycarbonate membrane  of this pore size. Liposomes were fused on recently cleaved mica by incubation at 65 °C, and excess was carefully rinsed with buffer afterwards. DMPE lipid bilayers were maintained at the desired temperature during AFM measurements using the JPK HCS . JPK Nano Wizard II was used for AFM characterization. HQ:XSC11/Hard/Al BS silicon rectangular cantilever probes from Mikro Masch , with a typical force constant of 0.2 N/m and a typical resonant frequency of 15 kHz, were employed in dynamic mode. Scanning was always done in buffer solution, temperature was controlled by the JPK heating-cooling stage (HCS).z-axis. Molecular dynamics calculations were carried out with GROMACS v4.5.4 molecular simulation package [TMCG molecules were constructed as described previously , and DMP package  under co package . All oth package . A total package  was emplThere is a large body of evidence which supports the view that phytochemicals, particularly catechins, exhibit great variety of biological functions which are beneficial to human health . In this6 cells [50 of 1.5 μM for TMCG in melanoma cells [The ratios between TMCG and phosphatidylethanolamine used in this study are similar to those commonly used in previous studies on the interaction between catechins and membranes ,27 and r6 cells . If we ama cells , it rendTMCG is a synthetically modified catechin and no data is yet available concerning physiological concentrations. In general, the issue of bioavailabilty of catechins is a very important one which needs to be addressed. In this sense, we believe that low concentrations of catechins in the blood stream would correspond to a much greater availability in the membrane fraction and they may accumulate over time to produce cellular concentrations that are much higher than that observed in serum samples. In addition, we would like to point out that the molar ratios studied in our model system are not necessarily required to be homogeneous in the whole cellular membrane. It would be enough that this TMCG/phospholipid ratio be attained locally in certain parts of the membrane. In this respect, the described propensity of TMCG to form enriched domains in the bilayer may help to locally attain higher concentrations of the molecule where it is needed.The incorporation of TMCG into membranes is mainly driven by its lipophilicity, and this incorporation is the first step in the sequence of events induced by this compound. We have shown that this molecule is located in the interior of the bilayer, this location being crucial to reach tyrosinase, a membrane protein which acting on TMCG produces an activated metabolite able to inhibit dihydrofolate reductase and thus explaining the antimelanoma effect of TMCG . In addiGiven the complexity of biological membranes, the investigation of the structural parameters of phospholipids presented in this work is not possible to be performed using native biological membranes. The presence or different classes of phospholipids, sterols, and also proteins makes the use of physical techniques impractical to study these properties of phospholipids. We used model membrane systems as valuable tools to study the properties of individual phospholipid species. Many more studies concerning the interaction between TMCG and anionic phospholipids, the presence of mixtures of phospholipids with different head groups, or the influence of the presence of cholesterol are needed to obtain a clearer picture of the interaction of TMCG and membranes.The compound under study was synthesized in order to increase the bioavalilabity of catechins and their ability to incorporate into cellular membranes and thus it differs from natural catechins in possessing a much more lipophilic gallic acid trimethylether moiety besides the polar phenolic groups at the catechin core. Thereby, a more pronounced amphiphilic character is induced which is likely to allow interactions with biological lipid bilayers in a more efficient way than would be expected for the natural congeners. Therefore, the results presented here should, at present, not be extrapolated to natural catechins such as those found, e.g., in green tea and other herbal preparations. Further studies will be required to investigate whether such membrane effects can also play a role in the bioactivity of these natural products.


Herein, we characterized Cyp27a1−/−Cyp46a1−/−Soat1−/− and Cyp27a1−/−Cyp46a1−/−Apoe−/− mice. In the former, retinal cholesterol levels, anatomical gross structure, and vasculature were normal, yet the electroretinographic responses were impaired. Conversely, in Cyp27a1−/−Cyp46a1−/−Apoe−/− mice, retinal cholesterol levels were increased while anatomical structure and vasculature were unaffected with only male mice showing a decrease in electroretinographic responses. Sterol profiling, qRT-PCR, proteomics, and transmission electron microscopy mapped potential compensatory mechanisms in the Cyp27a1−/−Cyp46a1−/−Soat1−/− and Cyp27a1−/−Cyp46a1−/−Apoe−/− retina. These included decreased cholesterol biosynthesis along with enhanced formation of intra- and extracellular vesicles, possibly a reserve mechanism for lowering retinal cholesterol. In addition, there was altered abundance of proteins in Cyp27a1−/−Cyp46a1−/−Soat1−/− mice that can affect photoreceptor function, survival, and retinal energy homeostasis (glucose and fatty acid metabolism). Therefore, the levels of retinal cholesterol do not seem to predict retinal abnormalities, and it is rather the network of compensatory mechanisms that appears to determine retinal phenotype.In mammalian retina, cholesterol excess is mainly metabolized to oxysterols by cytochromes P450 27A1 (CYP27A1) and 46A1 (CYP46A1) or removed on lipoprotein particles containing apolipoprotein E (APOE). In contrast, esterification by sterol-O-acyltransferase 1 (SOAT) plays only a minor role in this process. Accordingly, retinal cholesterol levels are unchanged in Soat1 CETP, ABCA1, LIPC, LPL, VLDLR, LRP6, and APOE, which encodes apolipoprotein E) as risk factors for AMD and suggested that these gene effects are independent of plasma lipid profiles .,26.−/−Cy−/− mice B. Yet, t−/− mice B, thus s− retina B, also a− retina C,D. Thes−/−Cyp46a1−/−Soat1−/− vs. WT mice (−/−Cyp46a1−/−Soat1−/− vs. WT retina as an expression of 7 proteins from the endosomal, secretory, and protrusion formation pathways (CHGA, HDAC6, PAFAH1B, SEPT6, SRP19, TAGLN2, and TAGLN3, −/−Cyp46a1−/−Soat1−/− retina followed by Cyp27a1−/−Cyp46a1−/−Apoe−/− and then WT retina (−/−Cyp46a1−/−Soat1−/− retina, vesicles were detected at both apical and basal RPE sides, possibly a reflection of the bi-directional traffic to the intraretinal and choroidal vascular networks. Traffic to the intraretinal vasculature was further supported by abundant vesicles in the intraretinal space of the outer nuclear layer and neurovascular units of the ganglion cell layer (−/−Cyp46a1−/−Soat1−/− retina.Next, we assessed the apolipoprotein-mediated retinal cholesterol traffic by measuring the mRNA for different apolipoproteins  and cond WT mice ; Table 2 WT mice  and for  WT mice . Rather,T retina . Notablyll layer . Also, tExtracellular vesicles are generally enriched with cholesterol as compared to other cellular membranes, and their release is usually enhanced from cells enriched with cholesterol . Therefo−/−Cyp46a1−/−Soat1−/− vs. WT retina (−/−Cyp46a1−/−Soat1−/− retina, there should be an increased production of ATP due to glycolysis and increased acetyl CoA availability as the latter is necessary for the tricarboxylic acid cycle, which provides NADPH for ATP production during mitochondrial (−/−Cyp46a1−/−Soat1−/− vs. WT retina (−/−Cyp46a1−/−Soat1−/− retina (−/−Cyp46a1−/−Soat1−/− retina (Vesicle formation requires energy , and remT retina  and partT retina . If enerhondrial  or extraT retina . The exp− retina  and coul− retina  but also−/−Cyp46a1−/−Soat1−/− mice (−/−Cyp46a1−/−Soat1−/− retina. In Cyp27a1−/−Cyp46a1−/−Apoe−/− mice, retinal function was dependent on sex and was normal in female animals (−/−Cyp46a1−/−Apoe−/− mice for comparison to Apoe−/− results [The present work provides insights into potential mechanisms that could underlie the deteriorations in retinal function in Cyp27a1−/− mice . Indeed,−/− mice  but all  animals , in agre−/−Cyp46a1−/−Soat1−/− retina. The absence of SOAT1 can increase the availability for the retina of fatty acids, which are used as the enzyme substrates, whereas the absence of CYP27A1 and CYP46A1 abolishes the production of 27-hydroxycholesterol and 24-hydroxycholesterol, which are activating ligands for LXRs. LXRs are important transcription factors that play essential roles in the regulation of cholesterol metabolism and also integration of glucose and fatty acid metabolism as well as immune and inflammatory responses [−/−Cyp46a1−/−Soat1−/− retina as a compensatory response to decreased LXR activation and/or increased fatty acid availability. This will lead to an increased energy production, which could be used to form extracellular vesicles, an energy-consuming process and alternate means to eliminate excess cellular cholesterol when the compensatory responses from cholesterol biosynthesis and efflux to LP are either not sufficient or not operative. In addition, decreased LXR activation could promote proinflammatory processes and affect retinal function. Apparently, other processes could also become affected in the Cyp27a1−/−Cyp46a1−/−Soat1−/− retina as suggested by retinal proteomics (We propose the following model  to unifyesponses . Accordioteomics . Future −/−Cyp46a1−/−Soat1−/− and Cyp27a1−/−Cyp46a1−/−Apoe−/− mice and identified some of the homeostatic responses to the blockage of the major pathways of retinal cholesterol output and storage. The major cholesterol-related response included the upregulation of the pathways producing intracellular and extracellular vesicles, which seems to be a reserve mechanism for retinal cholesterol removal. The non-cholesterol-related responses pertained to retinal function, photoreceptor viability, and possibly retinal glucose as well as fatty acid metabolism. The data obtained provide insight into the links between retinal cholesterol homeostasis and other important retinal processes. Notably, the content of total retinal cholesterol does not seem to predict retinal abnormalities, and it is rather the network of compensatory mechanisms that appears to determine the retinal phenotype.We comprehensively characterized the retina of Cyp27a1


Shewanella frigidimarina (SfIBP) to inhibit ice crystal growth in highly alkaline solutions with increasing pH and ionic strength was investigated in this work. The purity of isolated SfIBP was first confirmed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and size-exclusion chromatography with an ultraviolet detector (SEC-UV). Protein stability was evaluated in the alkaline solutions using circular dichroism spectroscopy, SEC-UV, and SDS-PAGE. SfIBP ice recrystallization inhibition (IRI) activity, a measure of ice crystal growth inhibition, was assessed using a modified splat assay. Statistical analysis of results substantiated that, despite partial denaturation and misfolding, SfIBP limited ice crystal growth in alkaline solutions (pH ≤ 12.7) with ionic strength I ≤ 0.05 mol/L, but did not exhibit IRI activity in alkaline solutions where pH ≥ 13.2 and I ≥ 0.16 mol/L. IRI activity of SfIBP in solutions with pH ≤ 12.7 and I ≤ 0.05 mol/L demonstrated up to ≈ 66% reduction in ice crystal size compared to neat solutions. The ability of a natural ice-binding protein from  Ice-binding proteins (IBPs) are a robust series of proteins found in a multitude of freeze-avoidant and freeze-tolerant organisms, including fish, fungi, plants, and bacteria, that are capable of surviving sub-zero temperatures by inhibiting ice crystal growth and controlling ice crystal morphology ,2,3,4,5.Leucosporidium significantly reduced hemolysis at concentrations of 0.4–0.8 mg/mL [Previous cryogenic research indicates that IBPs may offer a new, biomimetic alternative to conventional frost-prevention strategies for biological materials ,13 and, .8 mg/mL , and thr.8 mg/mL . The eff.8 mg/mL . As an e.8 mg/mL . ChangesRhagium inquisitor IBP was improved six-fold in 0.8 M monovalent ionic solutions of tri-sodium citrate, sodium chloride (NaCl), and sodium iodide. Leiter et al. [IBPs have been shown to exhibit control of ice structures at nanomolar (nM) concentrations of IBPs in solution ,22, and r et al.  studied r et al. . Taken tShewanella frigidimarinas (SfIBP) to control the size and inhibit the growth of ice crystals in highly alkaline solutions (pH > 12) with increasing ionic strength. First, the structural stability of SfIBP was investigated using circular dichroism (CD) spectroscopy. Second, SfIBP stability, aggregation, and degradation were analyzed with two protein size-analysis techniques, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and size-exclusion chromatography with an ultraviolet detector (SEC-UV). Finally, SfIBP IRI activity was investigated using a modified splat assay and compared to controls of neat solutions. Similar to precedent research [The purpose of this work was to investigate the ability of an ice-binding protein from the bacterium research ,26,27,282), potassium hydroxide (KOH), sodium hydroxide (NaOH), calcium sulfate (CaSO4), 2-mercaptoethanol, and bovine serum albumin (BSA) were purchased from Sigma Aldrich without further purification. Tris(hydroxymethyl)aminomethane buffer (Tris) was purchased from Fisher Bioreagents without further purification. Shewanella frigidimarina IBP isoform 1 (SfIBP) at a concentration of 4 mg/mL in solution was obtained from Dr. Peter Davies at Queen’s University in Kingston, Ontario, Canada [Calcium hydroxide (Ca(OH), Canada  and was I) for each solution was calculated according to Equation (1):Z is the valence of the ion and C is the ion concentration. As Tris has a pKa of 8.1, solutions with pH > 12 were above Tris’s buffer capacity. Therefore, Tris was determined to have dissociated completely to its conjugate base  and conjugate acid (H+), as per the Henderson-Hasselbach equation. Since Tris was in its deprotonated form, it was not included in the ionic strength calculations for solutions with pH > 12. The conjugate acid was expected to neutralize through combination with hydroxide ions present in alkaline solutions to form water, which would have been reflected in measured solution pH used to determine hydroxide concentration. Samples for IRI characterization without or with 0.125 mg/mL SfIBP were prepared using stock solutions from Hydroxide salts were used to create alkaline solutions of increasing pH in ~0.5 pH increments from pH ~12.5 to 14.0. Formulations were adapted from studies performed by Ghods et al. , and theSfIBP structure and stability were analyzed in two solutions , namely SfIBP stability, aggregation, and degradation were analyzed using size-exclusion chromatography (SEC) equipped with an ultraviolet (UV) detector monitoring a wavelength of 220 nm. SEC was performed on an Agilent 1100 Series LC system with a UV detector and a Tosoh TSKgel G3000SWxl size exclusion column. For all experiments, the mobile phase was 100 mM potassium phosphate buffer (pH 7.4) at a flow rate of 0.4 mL/min. Solutions from Sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed on SfIBP loaded into solutions from 0) and again at 30 minutes (t30) to observe ice recrystallization. Images were obtained using a Zeiss Axio Imager M2m microscope with an EC Epiplan 5x/0.13 BD M27 objective and crossed polarizers, equipped with an Axiocam 506 color camera on a 1” 1.0x 60N C-mount adapter. ZENCore 2.4 image processing was used to measure individual grain sizes along the major axis. Data were taken from images from 2–3 different splat samples and used to determine an average grain size (n = 150) at t = 30 min. A splat ice recrystallization assay was adapted from Knight et al. . Solutioa priori to p < 0.05. Simple effects  were assessed with the Fisher Least Significant Difference test using a Bonferroni correction to account for family-wise error . To determine if ionic strength and pH influenced mean grain size, these two solution chemistry metrics were first tested for intercorrelation using Pearson product-moment correlation. Since ionic strength and pH were found to be intercorrelated, no conclusions about the relative influence of pH versus ionic strength on mean grain size could be made. All statistical analyses were performed with Minitab (v18).Grain sizes were first averaged for each of the replicate images. The effect of solution  to find the maximum ionic strength that did not saturate the CD detector, which corresponded to solution A with Tris concentration reduced to 10 mM (A + 1/2 Tris). CD spectra could not be obtained for solutions B, C, or D, as the ion concentration of the solutions saturated CD absorption, preventing detection of SfIBP in the peptide bond region.An analysis of secondary structure using CD data of SfIBP in 1/2 Tris and its associated changes when placed in A + 1/2 Tris is presented in I ≤ 0.05 mol/L (solutions A and B) had a shape and elution volume similar to SfIBP in Tris , bands corresponding to intact SfIBP protein ≈ 25 kDa are evident. SfIBP exhibited faint bands in lower molecular weight regions (≈10 kDa) for all alkaline solutions except for solution D.The SDS-PAGE results are presented in IRI activities of all solutions listed in As expected, all solutions without SfIBP exhibited ice nucleation and growth upon incubation at sub-freezing temperatures (−4 °C). Ice crystallites with an average grain size of 51±19 µm formed in Tris without SfIBP, which were comparable in size to ice crystals formed in all alkaline solutions without SfIBP .I ≤ 0.05 mol/L, . ANOVA determined that (i) solution, (ii) inclusion of protein, and (iii) the interaction between solution and protein all significantly affected mean grain size at t = 30 min. Simple effects testing revealed that for solutions A , B , and Tris , including protein significantly reduced grain size (p < 0.0167)  with ain size b. SfIBP ain size . When in 0.0167) b. As expolutions b. The raThe structure and activity of the ice-binding protein SfIBP was investigated in solutions with high alkalinity and increasing ionic strength. The reduction in average ice crystal size in solutions A and B with SfIBP was statistically significant compared to neat solutions. However, in more alkaline solutions C (pH = 13.2) and D (pH = 13.9) with higher ion content , the protein stability and IRI efficacy decreased, which affected ice recrystallization inhibition.I ≤ 0.05 mol/L. SfIBP degraded in solution D, as indicated by the lack of gel stain in SDS-PAGE  with ionic strength SDS-PAGE b. ProteiSDS-PAGE a to elutlution D a corrobolution D b.I ≤ 0.05 mol/L, chromatograms retained traces with absorbance peak shapes similar to SfIBP in Tris, along with evidence of some degradation. SfIBP in solutions A and B both exhibited UV absorbance peaks at 10 mL, similar to that of SfIBP in Tris, indicating retention of some protein. However, solutions C and D did not exhibit UV absorbance peaks at 10 mL, indicating degradation and, hence, a lack of protein structure that could exhibit IRI activity. The peak at 6 mL in solution C is decidedly an artifact due to the proportionally small signal, verified by the lack of higher molecular weight bands in SDS-PAGE.According to SDS-PAGE and SEC-UV, SfIBP exhibited some protein degradation in all solutions. Sample eluting at volumes of 12.5 mL and greater indicate that the high alkalinity and ion content of the solutions likely caused some degree of protein restructuring and degradation ,37. At iProtein misfolding does not necessarily equate to loss of ice-binding functionality , as someDue to the high alkalinity and ionic nature of the solutions , it was I = 0.01 and I = 0.03 mol/L, respectively), the elevated pH of solution A likely caused SfIBP to misfold  and highest alkalinity (pH = 13.9) of all tested solutions. Solution D was the only solution where SfIBP did not exhibit a band at ≈ 25 kDa in the SDS-PAGE gel  cannot be determined directly through CD, it is hypothesized that further denaturation and decomposition occurred that prevented inhibition of ice crystal growth, as determined by the lack of IRI behavior of SfIBP in solutions C and D . The meaI ≤ 0.05 mol/L, indicating that SfIBP (and other IBPs) could be effective at mitigating frost-induced damage in applications that necessitate activity in non-native chemical environments. It is clear from these data in SfIBP exhibits IRI activity in alkaline solutions (pH > 12) with ionic strength Tenebrio molitor [Marinomonas primoryensis [While SfIBP exhibits a potential to reduce frost-induced damage in select highly alkaline environments, other IBPs and new classes of biomimetic polymeric materials may prove more effective. Certain IBPs are well known to contain structures with a high density of stabilizing di-sulfide bonds, such as IBPs from  molitor , which ooryensis , requireoryensis ,41,42. Shewanella frigidimarinas (SfIBP) to inhibit and control ice crystal nucleation and growth in highly alkaline solutions of increasing pH and ionic strength. While the folded structure of SfIBP in media with ionic strength I > 0.03 mol/L could not be determined directly through CD, based on evidence from SEC-UV and SDS-PAGE, it is assumed that a greater extent of denaturation and degradation occurred at higher ionic concentrations (I ≥ 0.16 mol/L) that prevented the inhibition of ice crystal growth, as determined by the lack of IRI behavior. Despite protein misfolding, data indicate that SfIBP exhibits ice recrystallization inhibition (IRI) activity in solutions with high alkalinity (pH = 12.4 to 12.7) and low ionic strength (I ≤ 0.05 mol/L) . In conclusion, these results suggest that SfIBP (and other IBPs and their biomimetic synthetic replicates) could be effective at mitigating frost-induced damage in applications with chemically extreme non-native environments. This study evaluated the potential of an ice-binding protein (IBP) from


Studies on the effect of occupational noise have been widely performed for occupations such as construction workers, workers of factories or even musicians and workers of nightclubs. However, studies on the acoustics of church bells are very scarce and usually reported in languages other than English. In Spain, although the tradition of bell ringers is progressively getting lost, some bell ringers that continue transmitting the tradition remain. Church bells create sound with a large sound pressure level that can be heard from a great distance. However, despite the characteristics of the sound of church bells, bell ringers do not present symptoms of occupational hearing loss unlike musicians and construction workers. To determine the effects of the sound of the church bells on bell ringers, in this paper, an acoustic study of the church bells and a physiological study of the hearing abilities of bell ringers. Results show sound pressure levels reaching 120 dB inside the bell tower. The resulting hearing loss in bell ringers is small considering the great intensity of the sound produced by the bells. This is likely due to the short amount of time that bell ringers are exposed to the sound even if it reaches high sound pressure levels. The acoustic trauma or Noise-Induced Hearing Loss (NIHL), is defined as the permanent functional damage in the ear caused by the exposure to high intensity sounds. It can emerge in an acute manner after a single exposure to intensities higher than 140 dB, or chronically by a maintained exposure to more than 80 dB. The NIHL is a sensorineural hearing loss (SNHL) that initially manifests as a loss in 4000 Hz. As the NIHL progresses, the damage affects all high frequencies. In the tonal audiometry with extension in high frequencies, the repercussion is evidenced in frequencies higher than 8000 Hz, predominantly between 14,000 and 16,000 Hz. Usually, hypoacusis is bilateral and symmetric. However, if the exposure is acute, it is possible to find one sole affected ear. Furthermore, the association between tinnitus and otalgia after the exposure is frequent. The factors that contribute to the NIHL are dependent both on the sound and the subject. Intensities higher than 80 dB, extended exposure times, the frequency of the noise (being frequencies between 2000 and 3000 Hz the most harmful), the type of noise (where discontinuous or intermittent noises generate the most damage), and the environment (where a greater damage is caused when the exposure takes place in enclosed venues with strong reverberation or inadequately soundproofed venues) are some of the factors that depend on the noise. The factors that depend on the subject include sensitivity of the individual, age and otological background.Most of the published papers on acoustic traumatism evaluate hearing loss produced by irregular and disharmonic sounds ,2,3,4,5.Construction of the bell tower of the Cathedral of Valencia, known as the Micalet or Miguelete finalized in 1415. Its height is 50.85 m  and its longitude is the same as the perimeter of its base. The inside of the tower is accessed through a spiral staircase. There are 13 bells on the tower, eleven of them in the bell room and two on the belfry. The bells of the belfry  are dedicated to marking the hours and are currently activated electronically. Therefore, they have been excluded from this study.The architectural characteristics of the bell tower lead to the physical characteristics of the final sound generated by the bells being determinant in the results obtained from studying the hearing of the bell ringers. The tower, which has an octagonal base, has four bodies and a belfry. The walls are made of ashlar stone and have a width of 3.9 m. The bells are in the fourth body, housed in the openings to the outside that are on each side of the octagon. The measurements of said openings are 2 m of width and 7.6 m of height. The upper half of the opening is diaphanous, and the lower half is closed with wood doors that absorb the sound and project it in an amplified manner to the exterior and in a buffered manner to the interior. Similar to what happens to the acoustic box of a guitar. The ceiling of the bell room is pointed and its physique, and probably its height as well, influence the quality and the propagation of the sound. For the performance, the bell ringers are located on top of a wooden beam which requires good balance. Therefore, the bell ringers perceive a sound that results from the characteristics of each sound and the architecture of the Miguelete.Throughout the year there are different performances corresponding to different religious events. There are performances where only one bell is rung and others where some of them or all of the bells are rung. Each bell ringer controls one bell. However, sometimes one bell ringer may control two bells. The bells are made of bronze. They were made between years 1440 and 1816 and weigh between 317 and 1980 kg. The intensity of the sound on the point where the bell ringer is situated is between 100 and 125 dB, depending on the bell. At the middle of the room, the intensity varies between 110 and 125 dB, depending on the number of bells that bell ringers are ringing. Bell ringers are repeatedly exposed to high levels of noise. However, these high sound pressures may not impact their auditive and/or vestibular system. Currently, the group of bell ringers of the Cathedral of Valencia is comprised of volunteers that enjoy the art of ringing bells and transmit their knowledge from generation to generation. Bell ringers do approximately 200 performances a year. Not all bell ringers perform at all the performances. The duration of each performance varies from 15 to 30 min. Some days there may be several performances with rest periods ranging from 30 min to several hours between each performance. For example, there may be a performance in the morning and another one in the evening. The oldest bell ringers accumulate 50 years of exposure and the youngest ones have been performing for 3 years. During the performance, bell ringers maintain a distance to the bell between 15 and 100 cm and, habitually, they do not use any hearing protection. The objective of this study is to evaluate the hearing and balance of the bell ringers of the Miguelete tower of the Cathedral of Valencia.This paper is structured as follows: Physiological studies on the hearing ability of workers exposed to high levels of noise during their every-day activities at their workplace are quite abundant. Armando Carballo et al. presented in  a study Lastly, preventive measures are leading to the decrease in occupational hearing loss in industrial countries. Stucken et al. presented in  a study Another study on occupational hearing loss is performed by Kovalova et al. in . The stuAlthough studying the effects of occupational noise on workers of the construction or music industry is rather common, the effects of the sound of church bells on bell ringers and the acoustic properties of church bells are a fairly unexplored, and more so in the English language. On 1984, Rossing performed a study on the acoustic of bells [For this paper, the sound level of the group of bells of the Cathedral of Valencia was studied so as to assess the noise bell ringers were exposed to when performing. The sound of the bells was measured as a whole. Furthermore, physiological tests were performed to the bell ringers and a control group to determine the impact of their activities as bell ringers on their hearing abilities.In this subsection, the description of the bell tower and the deployment of the sonometers is presented. The bell tower of the cathedral of Valencia is a 50.85 m tall tower till its terrace and around 63 meter till its peak, made of stone with an orthogonal base. The bell room is comprised of eight windows where seven are occupied by bells and the last one is occupied by the stairs. The windows are provided with wood panels that act as an acoustic baffle. The information of the bells located at the bell’s room is presented in Measures were taken on the outside of the tower as well. In this subsection, the results from the inside and outside sonometers, as well as from the accelerometer, are depicted. Among the inside sonometers, one of them performed measures of a duration of 30 s, while the other two performed measures of 15 min. The evolution of the continuous sound pressure level for each frequency band and each sample is presented in For the other two sonometers, the continuous sound pressure level in dBA for a duration of the measure of 15 min is presented in LAeq stands for the equivalent sound pressure levels measured in dBA. LAFmax is the maximum sound pressure level expressed in dBA and measured in FAST mode. The FAST mode is a time weighting characterized for a time of 125 milliseconds for both up and down. This time weighting is performed by the sound meter and is usually utilized to measure noise. Lastly, LAFTeq stands for maximum sound pressure level in one takt as defined in the standard DIN45641 and is provided by the sound meter as well. As it can be seen in The vibration of walls and other materials may cause noise as well. Therefore, we performed some measures with an accelerometer so as to determine the vibration caused by the movement of the bells. Lastly, The continuous sound pressure level in dBA for the three points where the outside measures were taken are presented in The continuous sound pressure level for each frequency band at the Point 1 of the map is presented in The continuous sound pressure level for each frequency band at the Point 2 of the map is presented in The continuous sound pressure level for each frequency band at the Point 3 of the map is presented in In this section, the physiological study on the hearing abilities of the bell ringers is depicted. The data acquisition process is explained as well as the characteristics of the subjects that participated on the study. Furthermore, the results are explained.In this subsection, the study performed on the bell ringers of the Cathedral of Valencia is going to be presented. The study has been performed in a tertiary hospital with the knowledge of the ethical committee. The study was performed with two groups being the experimental group and the control group. The subjects included on the study were those that met the definition of an otologically normal subject: a person with normal health that does not present any sign or symptom of hearing disease, without cerumen plugs in the auditory canals and that has not been exposed in the past to excessive noises nor potential ototoxic medicines, nor presents a congenital hearing loss. The experimental group did not refer in any case to exposure to noise other than that of the bells.Five ears, correspondent to three bell ringers, presented hypoacusis known before being a bell ringer. In two participants, the hypoacusis was neurosensorial bilateral and in one of them it was conductive unilateral. Those five ears were excluded from the study. None of the cases presented symptoms compatible with vestibular pathologies among their antecedents. However, the three patients with previous hypoacusis were excluded from the vestibular exploration.The methodology utilized to perform the physiological study is presented in this subsection. Specifically, a detailed anamnesis of the exposure to noise and ototoxics and, medico-surgical and occupational antecedents of the subjects was performed. Otomicroscopy was performed before the instrumental explorations. The audiological examination consisted in a tonal audiometry (in dB HL) with extension to high frequencies , discomfort threshold, vocal audiometry, acoustic transitory oto-emissions and distortion products, tympanometry and stapedial reflex. The audiometry was performed with standard earphones. The stimuli were pure tones at all the frequencies using the recommended procedure Pure-tone air-conduction and bone-conduction threshold audiometry with and without masking, published by the British Society of Audiology . It is iThe vestibular exploration consisted on a dynamic computerized posturography, cervical and ocular vestibular evoked myogenic potentials, video head impulse test and vibration-induced nystagmus with videonystagmograph recording. Once the hearing thresholds were obtained, the correction of the hearing threshold was performed according to the Norma ISO 7029:2000 Distribución estadística de los umbrales de audición en función de la edad  .2 established for each age by the ISO normative. Afterwards, this value was subtracted from each hearing threshold obtained from the subjects. This way, the threshold corrected by age was obtained. Hypoacusis was established when the threshold corrected by age was above 20 dB.The calculation of the hearing threshold for an otologically normal population was performed for each age employing Equation (1):The statistical analysis of the audiometric results was performed employing the SPSS 21 software program. A multivariate analysis of the variance (MANOVA) was utilized for frequencies between 125 and 8000 Hz. This way, we studied several dependent variables in the same analysis, avoiding the accumulation of type 1 error that occurs in each individual statistical analysis. The T of Student test for independent variables was utilized for each of the frequencies ranging from 9000 to 16,000 Hz.The results of the performed tests are presented in this subsection. At the control group, the average auditive threshold corrected by age for conventional frequencies (125–8000 Hz) was below 10 dB for all frequencies. The auditive threshold for high frequencies was below 8 dB for all frequencies. The experimental group with the average auditive threshold corrected by age on conventional frequencies (125 Hz–8000 Hz) was below 20 dB for all frequencies, except for frequencies of 3000 Hz (21 ± 25 dB) and 8,000 Hz (21 ± 16 dB). The average threshold at 4000 Hz was 18 ± 13 dB . The average auditive threshold at the auditive study employing a high frequency audiometer is presented in The average discomfort threshold for frequencies of 250 Hz, 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz was 105 ± 9 dB, 113 ± 12 dB, 112 ± 11 dB, 112 ± 11 dB and 111 ± 13 dB, respectively. The difference between the hearing threshold and the average discomfort threshold (dynamic range) for the aforementioned frequencies were 93 dB, 102 dB, 103 dB, 97 dB and 89 dB, being above 70 dB for all the subjects .The average threshold from where the participants were able to understand the 0%, 50% and 100% of the words from the vocal audiometry was 13 ± 4 dB, 18 ± 7 dB and 38 ± 14 dB, respectively.S  in 2 ears (6.5%) and a type AD  in 5 ears (16.1%).According to the Jerger classification, a type A tympanogram  for 24 ears (77.4%), type AThe presence of stapedial reflex on all frequencies was confirmed for 26 ears (83.9%). The absence of stapedial reflex was detected at 2000 Hz for 1 ear (3.2%), at 4000 Hz for 2 ears (6.5%), at 5000 Hz for 1 ear (3.2%) and at all frequencies for 1 ear (3.2%) . All theD tympanometry and the negative stapedial reflex in 2000 Hz, reflecting alterations in the middle ear that could be the cause of the absence of TEOAE.Transitory evoked otoacoustic emission (TEOAE) was registered in 28 of 31 ears (90.3%). No register was obtained from three ears (9.7%). Two of the ears with missing TEOAE had SNHL in the PTA: one ear with thresholds of 35–50 dB between 3000 and 6000 Hz and another ear with thresholds of 65 dB from 3000 Hz, affecting the entire range of high frequencies. One of the ears in which no TEOAE was recorded presented normoacusis in the PTA, being in this case type APositive TEOAE were recorded in 18 ears with SNHL in the PTA: four ears with hearing loss from 16,000 Hz, two ears with hearing loss from 10,000 Hz and three ears with hearing loss from 8000 Hz, of which one ear presented thresholds of 35–40 dB in 3000 and 4000 Hz, three ears presented hearing loss from 4000 Hz and four ears presented hearing loss from 3000 Hz and affectation of the rest of the high frequencies. The majority of ears of the experimental group presented normal thresholds in the middle frequencies. Likewise, the presence of TEOAE demonstrates absence of lesion of the hair cells in this region of the cochlea. On the other hand, the presence of positive TEOAE did not rule out affectation of high frequencies from 3000–4000 Hz.For the Distortion Product Otoacoustic Emission (DPOAE), six of 31 ears were negative (19.35%). DPOAE were recorded at all the studied frequencies in 25 of the 31 ears of the experimental group (80.65%). Positive DPOAE were obtained in 14 ears with SNHL in the PTA. Seven ears were affected by frequencies between 3000 Hz and 6000 Hz with thresholds between 20 and 50 dB and seven ears were affected by high frequencies from 8000–10000 Hz with normal thresholds in the rest of the frequencies. The DPOAEs were negative in the experimental group for six ears with SNHL in the PTA. Three ears had thresholds between 35 and 70 dB in 3000 Hz, 4000 Hz and 6000 Hz and affecting high frequencies, two ears with thresholds between 30 and 40 dB in the frequencies 1500 to 3000 Hz and rest of normal high frequencies and one ear with thresholds of 60 and 90 dB at 4000 Hz and 6000 Hz.In the six ears in which DPOAE was not recorded, the hearing threshold in the PTA between the frequencies 2000 Hz and 6000 Hz was higher than the threshold of the ears with DPOAE. The mean threshold in the PTA in ears with positive DPOAE between 2000 Hz, 3000 Hz, 4000 Hz and 6000 Hz was 13 ± 6 dB, 19 ± 12 dB, 17 ± 11 dB and 20 ± 12 dB, respectively. The mean threshold in the PTA in ears with negative DPOAE between 2000 Hz, 3000 Hz, 4000 Hz and 6000 Hz was 28 ± 7 dB, 38 ± 12 dB, 43 ± 20 dB and 48 ± 32 dB, respectively.In the experimental group, the absence of DPOAE correlated with hearing loss greater than 35 dB in the region of 3000 Hz to 6000 Hz, although in some ears with loss of 50 dB they were positive. Although the DPOAEs correlated better with the tonal thresholds between 2000 Hz and 5000 Hz than the TEOAE. Their presence did not rule out lesion in the hair cells of the basal regions of the cochlea (8000 Hz).p = 0.007), 2000 Hz (p = 0.001), 3000 Hz (p = 0.002), 4000 Hz (p = 0.049) and 8000 Hz (p = 0.020) frequencies , 250 Hz (p = 0.403), 500 Hz (p = 0.324), 1000 Hz (p = 0.770) and 6000 Hz (p = 0.068) frequencies. As it can be seen, there are points in the frequencies of 125 Hz and 1500 Hz were the hearing ability of the bell ringers is a little bit better. However, as it is shown in For these frequencies, the experimental group presents the highest auditive threshold. There have not been found any significant differences for the 125 Hz , and 10000 Hz (p = 0.023) frequencies. For both cases, the effect has a medium-big size. Therefore, we can conclude that the exposure to the sound of the bells has an effect on the hearing for these frequencies. There have not been statistically significative differences for the 11200 Hz (p = 0.071) frequency. However, this value is near alpha and the size of the effect is medium. Lastly, there have not been found significative differences for the 14000 Hz and 10000 Hz frequencies, with a nearly non-existent effect size.  were between 0.8 and 1.2 for the six channels in all subjects, and no out of correction events were observed.Spontaneous nystagmus was not observed in the videoinstamography of any participant. Furthermore, nystagmus did not appear when applying vibration of incremental frequencies  from the mastoids of any subject. Symmetric vestibular evoked myogenic potentials were observed in the 15 studied subjects.The average value obtained at the sensorial organization test of the posturography was of a 82%, with a standard deviation of 8%. Two subjects presented a result below the normal limit for their age and size.In this section the obtained results of the physiological study are discussed. Acoustic trauma produces a SNHL that mainly affects high frequencies, with the scotoma at 4000 Hz, being the first finding in the tonal audiometry .Multiple studies relate continuous exposure to noise in the workplace with hearing loss due to acoustic trauma ,2,3,4,5,According to the published literature , the heaHigh frequencies intervene in the location of sound  and the Otoacoustic emissions (OAE) are sounds of low intensity generated by the cochlea that leave to the middle ear and are detected in the external auditory canal. They are a product of the motility of the outer hair cells, which is why they represent a non-invasive objective technique for the study of preneural cochlear function, contributing to the differentiation between sensory and neural dysfunction . The preThe TEOAE use as a stimulus a non-linear sequence of broadband tones or clicks with a sound pressure level of 70–84 dB SPL (45–60 dB HL) and stimulate a wide range of frequencies, between 1500 and 4500 Hz . They arThe DPOAEs are produced simultaneously using two tones of different frequencies: f1 and f2 (f2/f1 = 1.24), it being possible to configure f2 in a range of 1000 to 6000 Hz. The presence of otoacoustic emissions indicates that the outer hair cells are functioning in the frequency region of f2 . In our Differences were found with the general population in the vestibular study performed on the bell ringers, finding the average values obtained within the limits of normality for each age. Therefore, we cannot conclude that exposure to noise produces affectation at vestibular level.Although the bell ringer tradition is getting lost, in the Cathedral of Valencia there are still several voluntary bell ringers that perform on special occasions. However, the high sound pressure levels given by the bells produce low hypoacusis in the bell ringers. In this paper, we performed an acoustic study of the sound produced by the bells and a physiological study of the hearing abilities of the bell ringers. The sound of the bells reached 120.32 dBA inside the bell tower and a maximum of 91.59 dBA outside the tower. The physiological results confirmed that bell ringers did not present hearing loss related to their occupation.As a future work, we plan on studying the hearing abilities of the bell ringer of other churches and cathedrals in Spain so as to confirm the hypothesis presented in this preliminary study. The results of these studies could aid in developing hearing protections specific for bell ringers as in  so as to


Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder of the peripheral nervous system. The economic burden of CIDP is not well understood.To assess the economic and clinical burden of CIDP and to compare the incremental burden relative to a matched control group without CIDP.This retrospective case-control analysis was conducted using data from the IQVIA Real-World Data Adjudicated Claims. Adults newly diagnosed with CIDP between 7/1/2010 and 6/30/2014 were identified and direct matched to controls without CIDP. Baseline characteristics were assessed and compared over a 6-month pre-index period. Healthcare resource use, costs and clinical characteristics were assessed and compared over a 2-year follow-up. Total cost differences over the 2-year follow-up were compared between matched cohorts using a generalized estimating equation model.The final sample comprised a total of 790 cases matched to 790 controls. Over the 2-year follow-up, cases more frequently experienced neuropathic pain, back pain and osteoarthritis and more commonly utilized opioids, anti-convulsants and anti-depressants. Compared to controls, more cases had ≥1 hospitalization (26.2% vs. 9.0%), and cases had a higher mean number of outpatient prescription fills (62.8 vs. 32.0) and physician office visits (34.7 vs. 13.0) . Cases had 7.5x higher mean total costs . Important cost drivers were costs for outpatient ancillary, radiology and HCPCS drugs  and costs for inpatient care  (both p<0.0001). Among cases, CIDP therapy  accounted for 51.2% of mean total costs. After further adjusting for baseline clinical characteristics, cases were associated with a 6.1x increase in total costs compared to controls (p<0.0001).Our findings suggest a substantial clinical and economic burden among patients with CIDP relative to matched controls over a 2-year follow-up. Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, chronic, acquired immune mediated disorder of the peripheral nervous system, characterized by progressive, symmetrical limb weakness, large fiber sensory loss and loss of reflexes –3. InitiThere has been increasing concern about misdiagnosis and over-diagnosis of CIDP in current clinical practice ,6. Not sThe primary goals of treatment for CIDP are to reduce symptoms, improve functional status  and maintain long-term remission as possible . AccordiThe economic burden of CIDP is not well understood. Two published studies have identified substantial costs associated with CIDP ,13. No pThis retrospective case-control analysis was conducted using IQVIA Real-World Data (RWD) Adjudicated Claims, using data from January 2010 through June 2016.IQVIA RWD Adjudicated Claims is one of the largest US health plan claims databases and is comprised of adjudicated claims for more than 150 million unique enrollees across the US. The database is considered representative of the national, commercially insured population in terms of age and gender. Standard fields include inpatient and outpatient diagnoses and procedures, and retail and mail order prescription records and payments. All data are compliant with the Health Insurance Portability and Accountability Act (HIPAA) to protect patient’s privacy.US managed care enrollees were initially identified in IQVIA RWD Adjudicated Claims based on ≥1 medical claim with a diagnosis for CIDP ICD-9-CM 357.81) between July 1, 2010 and June 30, 2014. Both confirmatory and non-confirmatory  claims were considered. The date of the first claim was termed the “index date.” Patients were required to have confirmation of CIDP denoted by: 1) a subsequent confirmatory medical claim with a diagnosis for CIDP or 2) initiation of CIDP therapy within 1 year of the index date. CIDP therapy was identified based on a broad list of available therapies or procedures which have been proven or investigated in CIDP  [3].57.81 betPatients were required to have ≥6 months of continuous enrollment (CE) in the health plan before the index date  and to have ≥2-years CE following the index date . Patients were required to be newly diagnosed with CIDP as of the index date and were excluded if they had any medical claims with a diagnosis for CIDP or if they had any claims for CIDP therapy in the 6-month pre-index period. Finally, only adults were included (≥18 years old at index) and patients were excluded if they had poor data quality .Patients with CIDP (cases) were matched to patients without CIDP (controls). Cases were direct matched to controls based on: age, gender, geographic region, health plan type, payer type and Charlson Comorbidity Index (CCI) score. The index date for controls was set as the index date of the matched patient with CIDP. Controls had neither medical claims with a diagnosis for CIDP nor claims for CIDP therapy at any time during the study period. Controls were required to be ≥18 years old, to have ≥6-months pre- and ≥2-years post-index CE, and to have adequate data quality.Baseline demographic and clinical characteristics were assessed for cases and controls. Demographic characteristics included age, gender, health plan type, payer type and geographic region at index. Clinical characteristics were measured over the 6-month pre-index period and included the CCI, common and relevant comorbidities of interest, prior use of therapies of interest and total healthcare costs. Alternative pre-index diagnoses, i.e., occurring prior to confirmed CIDP diagnosis, which may be considered potential misdiagnoses ) and percentage (%) for each cohort. For continuous variables, both the mean (standard deviation [SD]) and median were reported. Study outcomes were compared between the matched cohorts using paired t-test (mean) and the Wilcoxon signed-rank test (median) for continuous variables and McNemar’s or Bowker’s test for categorical variables.A generalized estimating equation model (GEE) was developed, with a gamma distribution and log-link function, to evaluate differences in total healthcare costs over the 2-year follow-up between matched cohorts. The model included baseline clinical characteristics measured over the 6-month pre-index period that were significantly different between matched cases and controls, including back pain, use of anti-depressants, anti-anxiety medications, anti-convulsants, benzodiazepines, central muscle relaxants, NSAIDs, and opioids, number of outpatient physician office visits and total healthcare costs.A p-value of <0.05 was considered statistically significant. All analyses used SAS version 9.3 .A total of 10,672 patients were identified with a medical claim with a diagnosis for CIDP between July 1, 2010 and June 30, 2014 and were evaluated for study inclusion . A few comorbidities in the 6-month pre-index period were significantly higher among cases compared to controls including neuropathic pain (39.7% vs. 2.9%), back pain (30.5% vs. 10.1%) and osteoarthritis (8.2% vs. 3.3%) .Baseline clinical characteristics can be found in A number of therapies of interest were more frequently used in the 6-month pre-index period among cases compared to controls including anti-convulsants (30.6% vs. 5.1%), opioids (33.4% vs. 16.2%) and anti-depressants (27.3% vs. 13.7%) . More cases had a hospitalization compared to controls . Cases also had a higher mean number of outpatient physician office visits (8.0 vs. 4.1) and higher mean total costs  (both p<0.0001). In the 6-month pre-index period, 39.4% of cases had ≥1 physician office visit to a neurologist and 10.4% had ≥1 physician office visit to an orthopedic surgeon, compared to 2.2% and 3.5% of controls, respectively.Over the 2-year follow-up, 657 patients (83.2%) initiated CIDP therapy in a median of 52 days. Among patients that initiated CIDP therapy, the majority (57.4%) initiated monotherapy with corticosteroids, while 27.5% initiated monotherapy with IVIg and 8.2% initiated combination therapy with corticosteroids and IVIg. Among patients that initiated CIDP therapy, 83.1% had any use of corticosteroids and 41.2% had any use of IVIg over the entire 2-year follow-up; utilization of other CIDP treatments was infrequent (<5%) and included mycophenolate mofetil (4.4%), azathioprine (4.1%) and PE (4.0%).Over the 2-year follow-up, CCI score was higher for cases than controls  . A numbeOver the 2-year follow-up, HCRU was significantly higher among cases. Proportion with utilization of a service was significantly higher among cases compared to controls including proportion with ≥1 hospitalization (26.2% vs. 9.0%), ER visit (42.2% vs. 21.9%) or outpatient surgical visit (77.1% vs. 45.9%) . More cases had ≥1 neurologist office visit (67.0% vs. 3.9%) or physical therapy visit (14.7% vs. 2.8%) (both p<0.0001). Number of healthcare services per patient was also significantly higher among cases including mean number of outpatient prescription fills (62.8 vs. 32.0) and physician office visits (34.7 vs. 13.0) (both p<0.0001) .Over the 2-year follow-up, total costs were significantly higher for cases than controls  See . CompareIn the GEE of total healthcare costs over the 2-year follow-up, cases were associated with a 6.1x increase in total costs compared to controls (p<0.0001).This study represents to our knowledge the first real-world database study to quantify the incremental burden of CIDP using a matched case-control analysis. Our findings suggest a substantial clinical and economic burden among patients with CIDP compared to matched controls. Over the 2-year follow-up, common symptoms of CIDP included neuropathic pain, back pain and osteoarthritis. Medications such as anti-convulsants, anti-depressants and even opioids were frequently utilized. A third of cases newly used opioids following initial diagnosis. We observed that a number of clinical characteristics appeared to increase for cases in the 2-year follow-up compared to the 6-month pre-index including CCI score, and presence of neuropathic pain, back pain and osteoarthritis. Over the 2-year follow-up, cases had significantly higher HCRU compared to controls, including more patients with ≥1 hospitalization and a higher number of physician office visits. Cases were associated with 7.5x higher mean total healthcare costs compared to controls. Outpatient ancillary, radiology and HCPCS drugs comprised the majority of total costs, while inpatient care was also an important cost driver. Half of total costs for cases over the 2-year follow-up were attributable to CIDP therapy . Following further adjustment in the GEE, cases were associated with a 6-fold increase in total healthcare costs compared to controls.The frequent use of opioids observed among CIDP cases is concerning. We have no way of identifying whether opioids were prescribed for the CIDP or, as is likely, for observed comorbid neuropathic or chronic pain due to the limitations of the study database. While severe pain is unusual in CIDP, it appears that comorbid pain-related conditions were relatively common among our cases. We found that almost half of cases experienced back pain and almost a quarter experienced osteoarthritis over the follow-up. Yet, the use of opioids, even if for neuropathic pain, remains controversial and opioids do not provide improvements in physical functioning among those with neuropathic pain ,15. FurtOnly one identified study has previously evaluated total healthcare costs among CIDP patients in the US . A totalWe did not evaluate costs of specific CIDP therapies in this analysis. In an exploratory analysis, we observed that patients initiating monotherapy with IVIg had higher CIDP therapy costs than patients initiating monotherapy with corticosteroids. From treatment initiation to the end of the 24-month follow-up, corticosteroid patients had mean (SD) CIDP therapy costs of about $7,900  while IVIg patients had mean CIDP therapy costs of $165,000 $170,000). IVIg patients had higher costs, in part, related to longer persistence on IVIg compared to corticosteroids. The long-term clinical and economic impact of greater discontinuation of steroids compared to IVIg is unknown. Further, the claims data do not provide any insights into clinical effectiveness. Yet, our observation of high CIDP therapy costs, and high costs of IVIg specifically, highlights the importance of optimally managing the treatment of CIDP while considering both clinical benefit and costs. Setting of care has also been identified as an important cost driver for IVIg, with IVIg administration in the outpatient hospital setting associated with higher costs compared to IVIg administration in the home setting 0,000. IV. While wThis study has limitations inherent to retrospective database studies, as well as to the data source and study design. Results from retrospective studies should be interpreted with understanding of their inherent limitations, and in context of results from other similar studies. Administrative databases do not provide as much clinical detail, for example, treatment outcomes or disease severity, as medical records. We relied on diagnosis and therapy codes on administrative billing claims to identify patients with CIDP; however, CIDP is often misdiagnosed ,7 AlthouOur study constitutes the largest retrospective real-world database study of the economic burden of CIDP in the US and is the only study to quantify the incremental burden of CIDP relative to matched controls. Our findings suggest a substantial clinical and economic burden associated with CIDP. Over the 2-year follow-up, cases had higher healthcare resource utilization which was associated with 7.5x higher mean total healthcare costs compared to controls. This study provides important insights into the economic burden of CIDP; however, future studies are necessary to understand the economic burden among different patient populations as well as from indirect and societal perspectives. Future research is also needed to investigate optimal therapeutic strategies in CIDP to balance the costs and outcomes of therapy.


Due to the large number of individuals with Unilateral Hearing Loss (UHL) and the recommendation to use hearing assistive devices, studies are required to define possibilities of intervention for this population. Objective: To evaluate the performance of the Remote Microphone System (RMS) in children with UHL. Methodology: Prospective clinical study with a convenience sample. Eleven children (mean age of 9.2 years) with severe and profound sensorineural UHL, hearing aid users and enrolled in regular schools participated in the study. They were evaluated using the Hearing in Noise Test (HINT), the Classroom Participation Questionnaire (CPQ), and the Sustained Auditory Attention Ability Test (SAAAT) with RMS. Results: HINT results were analyzed using variance to three criteria of repeated measures, which revealed differences between intervention, position, and time factors and significant interaction between these three factors. The comparative analysis of the results from CPQ showed significant differences in the statistical t-test (p=<0.001) for all subscales. The analysis of variance at two repeated measures criteria used in the study of SAAAT revealed a difference between intervention and time, and both interacted significantly. Conclusion: The RMS associated with a hearing aid was effective for individuals with UHL. The difficulties faced by children with unilateral hearing loss (UHL) are an essential demand in hearing health services. No consensus is reached on the treatment to this problem.,,Nontreatment of UHL is considered a standard of care assistance in many parts of the world. Historically, doctors and researchers believed children with this type of hearing loss could have normal development since they had only one compromised ear. However, in the late 1980s, researchers began to detect significant academic problems in this population. Since then, studies have suggested children with UHL have a significant risk of speech, language, academic, and behavioral delays.With identification and early intervention, parents learn about the impact of hearing loss on child development. In Brazil, this became possible after the approval of Law 12.303 of August 2, 2010, which makes the Universal Newborn Hearing Screening Program mandatory.In a recent study conducted in Ontario, Canada, with 20 children diagnosed with UHL, the mean age of identification was 4.6 months. Parents experienced significant uncertainty about the need to use amplification devices because the hearing loss and its potential impact on the child's development were considered minimal.In fact, among the communication difficulties caused by hearing loss, the ability to understand speech in noisy environments is a daily challenge,In classroom, understanding is critical for the child to master academic skills, such as determining the main idea, following directions, answering questions, and participating in class discussions. A sensory impairment can affect the concentration, grammatical and lexical knowledge, working memory, cognition, past experiences, and mental and physical state.Kuppler, et al.In another study, sustained auditory attention was evaluated in 90 children aged from 7 to 11 years. The children were separated in three groups, with 30 children each: normal hearing; diagnosed with mild bilateral conductive hearing loss; and diagnosed with mild bilateral sensorineural hearing loss. The authors concluded that sensorineural hearing loss causes greater impairment of sustained auditory attention when compared with conductive hearing loss.This ability can also be evaluated according to the period of the day and the type of school attended by the child. Picolini, et al.,,To initiate the rehabilitation process, hearing aids (HAs) are usually the first choice between electronic devices, minimizing the negative effects of hearing impairment on communication. However, HAs have one or more microphones that receive all sound signals, not just speech signals. For this reason, using this device may not guarantee a good signal-to-noise ratio, especially when, in addition to the background noise, other factors interfere with this relation, such as the distance of the sound source and/or reverberation.The development of HAs is based on studies on the spectral characteristics of speech and the results of perception tests with real or synthesized speech signals to provide acoustic information about speech signals that are more complete and closer to reality.The recommendations of the American Academy of Audiology (AAA)Since the 1980s, scientific studies on the consequences of UHL have increased. However, studies about the intervention process in this population are scarce. Thus, one suggested the use of bilaterally adapted RMS could favor speech perception, classroom behavior, and sustained auditory attention.To evaluate the performance of the RMS in children with UHL and users of HAs, concerning speech perception, sustained auditory attention, and classroom participation.A prospective clinical study, using a convenience sampling method, was conducted after the approval of the Research Ethics Committee (44955015.9.0000.5417) and TRIAL: RBR-5PGXYS, and after the agreement of parents or guardians, who signed the Informed Consent Form, and the consent of the individuals who participated in the investigation.To participate in the study, the children should meet the following inclusion criteria:–Diagnosed with severe or profound unilateral sensorineural hearing loss - UHL of 45 dB or higher  in the affected ear and limits no worse than 15 dB  in the normal hearing ear .–Effective users of HAs for at least one year, with daily use of 8 h confirmed by data logging and monitored periodically by professionals of the clinic.–No previous experience with RMS.–Enrolled in regular school.–Aged between 5 and 17 years - according to the national criteria for free acquisition of the RMS.–After adapting to regular use of the RMS (school period) for three months for the second application of the procedures.The study was carried out with 11 children , aged between 7 and 11 years, with severe unilateral sensorineural hearing loss (2 children) and profound congenital hearing loss (9 children). Six children had hearing loss in the left ear and five in the right ear. The mean age of detection of UHL was 4.4 years.The children used the Naida III UP Phonak HA and were fitted with a remote microphone system from the same company connected by a wireless coupler. To verify the electroacoustic characteristics of the device, the Audioscan Verifit® equipment  was used to verify transparency. As defined by the AAA,After the RMS fitting and verification, participants underwent the procedures in the following order:The test was conducted in free field conditions in a sound-treated room, according to the HINTPro 7.2 Audiometric System operating instruction manual. HINTPro is an equipment with an interface connected to a computer. The specific software for the test must be installed on the computer, and the free field stereo loudspeakers must be coupled to the HINTPro 7.2. Each list of 20 sentences was applied in the situations: quiet (Q), noise front (NF), noise right (NR), noise left (NL), and compound noise (CN). The sentences were presented at 0---0° azimuth. The presentation level was initially set at 45 dBA and varied in steps of 4 dB and 2 dB according to the correct repetition of the level. The competitive noise was introduced at 0-0°, 0-90°, 0-180°, and 0-270° azimuths at a fixed intensity of 65 dBA.A negative S/N ratio indicates greater difficulty in the test and better performance of the individual. The more negative the ratio, the greater the difficulty, because the signal is emitted below the noise intensity.The CPQ is a subjective assessment tool that provides a situational analysis of student participation in classroom. It is a student-rated measure that contains 28 auditory situations divided into four subscales: (1) Understanding Teachers; (2) Understanding Students; (3) Positive Affect; (4). Negative Affect.In each scale, the student scores choosing between 1 ; 2 (sometimes); 3 , and 4 .Students took the test individually. They could read the items independently or have the items read or signed for them by the researcher, but all participants completed the questionnaire alone. Participants completed this questionnaire on the day of the RMS fitting and three months after. The RMS was used daily in classroom.The SAAAT is based on the Auditory Continuous Performance Test (ACPT), which is clinically used to measure auditory attention, and was performed in the free field.To determine the performance in this test, the children were instructed to raise their hand upon hearing the target word “no”. Two types of errors were considered: inattention error, when the child did not raise the hand in response to the target word, and impulsiveness error, when the child raised the hand in response to another word other than “no”. The score was calculated adding the number of inattention errors to the number of impulsiveness errors.st presentation and the number of correct answers for the 6th presentation. The difference between these two numbers is called “decreased vigilance.”Vigilance was estimated by adding the number of correct answers for the word “no” during the sequence of the six presentations. The estimate was necessary to verify the decline in vigilance, i.e., the decline in the attention that occurred during the vigilance task, obtained by estimating the number of correct answers for the word “no” in the 1To verify the better form of fitting of the RMS, the evaluations were performed under the following conditions: (A) only with HA (hearing aid); (B) HA in the ear with hearing loss and RMS in both ears; (C) HA in the ear with hearing loss and RMS in the ear with normal hearing; (D) HA and RMS only in the ear with hearing loss. The children used the devices in the different conditions in classroom for 15 days each.To avoid learning effect on the evaluations, the different conditions were applied with a 15-day interval, according to KeithStatistical analysis was initiated by examining the data using the normality test (Shapiro-Wilk) and the variance homogeneity test (Levene). If normal distribution and homogeneity of variance are not considered significant, parametric tests would be used; otherwise, nonparametric equivalent statistical tests would be used.For the HINT data, there was a normal distribution of the data and homogeneity of the variances; therefore, the two-way repeated measures ANOVA (factors: Intervention and Time) and the Tukey's test were performed for multiple comparisons.For the results from the CPQ, the comparative analysis of the “teacher comprehension” and “peer comprehension” showed normal distribution of the data and homogeneity of the variances, so the Student's t-test was used. For the “positive and negative aspects,” data were not normally distributed, so the nonparametric Mann-Whitney test was used.For the SAAAT data, parameters of normality and homogeneity were verified; therefore, they were submitted to the test of analysis of variance for two criteria of repeated measurements.For all cases, a significance level of 5% was adopted.post hoc analysis allowed the verification of these differences, shown in Since HINT is a sentence repetition test, age is not expected to influence the results. The results were studied through analysis of variance for two criteria of repeated measures, in which differences between intervention and time factors were observed. However, the same test revealed a significant interaction between these two factors, and the Tukey's Improvement in the responses in all HINT situations using the RMS was observed.The comparative analysis of the results from the Classroom Participation Questionnaire, with and without the use of the RMS, showed significant differences in the statistical t-test (p=<0.001) for the subscales “teacher comprehension” and “peer comprehension”, since (Shapiro-Wilk test) homogeneity of variances (Levene's test) were observed in these cases. In the “positive aspects” and “negative aspects,” data were not normally distributed (Shapiro-Wilk test). The use of the nonparametric Mann-Whitney test indicated a statistically significant difference between groups  and 3.The classroom participation of the children evaluated presented significant results using the RMS in all categories.The analysis of variance at two criteria of repeated measures used in the study of the results of the SAAAT showed a difference between intervention and time, and both interacted significantly. The SAAAT presented statistically significant results in interventions C and D.The literature determines the use of the RMS as assistive technology for children with hearing loss, especially in classroom.The group studied presented a diagnosis of sensorineural hearing loss with severe (two children) and profound (nine children) degrees, without the prevalence of sex or ear. The mean age of detection of UHL was 4.4 years, as in the study in Ontario (Canada),The AAA protocolThe participants were fitted with HAs and used them for at least 8 h, suggesting that hearing loss affects the children's development in some aspects, such as school, attention, sound localization, and speech comprehension. For inclusion in the project, the children used the RMS regularly in classroom. The effectiveness of the RMS depends on its periodic verification.This study verified the effectiveness of the RMS through the performance of children with UHL in tasks of speech perception, classroom participation, and sustained auditory attention.Speech perception was evaluated through the HINT BrazilRegardless of the HINT application, the software itself uses the composite noise (CN), which is a weighted average of the NF/NR/NL conditions for the free field application. The results from the CN  after th–The study,The NR and NL results  were bet,,Regarding NF, the children studied presented lower rate of improvement by using the RMS, presenting a response value of −2.6 with the use of HA and the RMS positioned in the affected ear. This is the best result concerning the speech perception in noise front . These rThe value of −6.04 from the NB with HA and RMS in the affected ear  was simi,,, respectively. The results of this study were similar to other results found in the literature, such as the Hearing in Noise Test-Children and Nonsense Syllable Test.In a quietness situation, the expectation is that the RMS increases the level of speech perception by at least 10 dB concerning only the speech perception with a HA.The HINT was used to evaluate children and teenagers with cochlear implants, with different box placements and stimuli. The results were significant when comparing the responses with and without the RMS.The awareness of the teacher of children with UHL in classroom is necessary. Dancer, et al.Children spend at least 4 h a day in school, totaling 20 h a week. Antia, et al.Questionnaires are considered valuable instruments to verify the classroom performance of these children. The CPQ was used in this investigation.According to researchers,,“Positive Affect” in the CPQ refers to the student speaking in classroom, speaking with the teacher and participating in group discussions. It showed significant improvement in the results , suggestThe auditory attention of schoolchildren can be influenced by auditory alterations, causing impairment in attention and comprehension skills, and, consequently, compromising the performance and learning of these children.In this study, the SAAAT evaluated the change in the responses of sustained attention after using sound amplification devices, assuming the importance of attention to the learning process, especially in classroom with presence of noise. Considering that the total score in the SAAAT is quantified according to the number of impulsiveness and inattention errors, the participants presented a mean value of 4.0 after three months using the RMS , with beThis result can be justified since a favorable signal-to-noise ratio facilitates attention to tasks and improves response time. It happens because the children have a longer time to focus and concentrate on the stimulus when the teacher's speech becomes clearer, while ignoring the competitive stimulus.,According to the literature, younger children have a limited attention span and, as they develop it, the internal processing mechanism changes, increasing this capacity. Therefore, older children, aged 11 years, perform better than younger children in this ability.The participants used the HA/RMS in classroom according to the proposal of the study, with results with poor statistical significance. In the HINT and SAAAT evaluations, the children reported that classroom situations became easier to understand and, at the end of the period, they were less tired (less auditory effort). Informally, the children reported higher concentration to receive the teachers’ explanation and to better understand the subjects. The children also reported that asking the teacher to repeat what was just said during dictation activity was no longer necessary.In a systematic review of sound amplification devices for unilateral sensorineural hearing loss of severe and profound degrees in adults, the authors suggest researchers conduct further studies on effectiveness of sound amplification devices for this type of hearing loss, thus supporting efforts for new evidences.The results of this investigation evidence that the RMS should be indicated for children with UHL, mainly for use in classroom, regardless of the fitting condition.,,,This investigation was carried out with 11 children, because it is a study that requires periodic returns to the clinic, control of the use of devices and availability of equipment. Thus, the sample number is small, similar to international surveys conducted with children with UHL.The research participants presented superior results using the RMS in evaluations of speech perception, sustained auditory attention, and classroom participation, regardless of the fitting condition, suggesting the effectiveness of this device associated with a hearing aid for children with unilateral hearing loss.


We present the case of a young female patient diagnosed with Cogan's syndrome after the rapid onset of profond hearing and vestibular loss with concomitant eye symptoms. After appropriate medical treatment, her hearing did not respond and she underwent bilateral simultaneous cochlear implantation with findings of extensive cochlear ossification in both ears. The case and outcome are described in the body of the paper. Cogan's syndrome is a rare condition consisting of recurrent visual and auditory-vestibular deficits, causing patients to complain of visual loss, eye pain, hearing loss, tinnitus, and vertigo. The hearing loss can be progressive and lead to a severe to profound hearing loss in 50–85% of cases –4. This A 24-year-old female presented to the otology clinic with a seven-week history of sudden onset right sided hearing loss and vertigo. One week later, she suffered left sided hearing loss. One month after the onset of her symptoms, she was evaluated by a community otolaryngologist who suspected Cogan's syndrome (CS) due to concurrent blurry vision, photophobia, eye pain, and excessive watering. She was treated with high pose prednisone and referred to our center for evaluation by otolaryngology, ophthalmology, and rheumatology. Her past medical history was significant for asthma.Ophthalmology observed subepithelial corneal infiltrates, but they were not felt to be consistent with classic interstitial keratitis. She was prescribed steroid eye drops, and her vision and pain improved dramatically. Rheumatology felt she had atypical CS and started treatment with methotrexate.On presentation to clinic, her vertigo and imbalance had mostly resolved; however, her hearing did not improve. Initial audiogram and repeat audiogram after prednisone showed profound bilateral hearing loss with 0% speech discrimination bilaterally. MRI scan revealed enhancement of the otic capsule bilaterally . At the At surgery, patient was found to have significant ossification of the scala tympani on both ears. Fortunately, a full electrode insertion was completed on each side after a significant basal turn drill-out was performed . Five weeks after surgery, she was appropriately healed, and her devices were activated. During activation, elevated impedances were found on the right at electrodes 3, 12, 13, and 15, while the left side showed normal impedances. The increased impedances slowly decreased over time and are currently within the normal range, although elevated compared to the remainder of the electrodes. Currently, the patient is using cyclosporine drops in both eyes, both of which have good vision and are without pain. She continues to follow with rheumatology, who has prescribed a maintenance dose of methotrexate at 20 mg weekly. Five months after activation, she attained a word recognition score of 76%. She continues to show improvement in her implant performance without any signs of decrement.A rare entity, CS causes vision loss, hearing loss, and dizziness. Although the cause is unknown, it is thought to be due to an autoimmune process that attacks these tissues. This usually occurs in patient in the third to fourth decade of life. Physical exam findings of nonsyphilitic interstitial keratitis on slit-lamp examination of the eye, abnormal lab findings , and documented hearing loss on audiometry help to make the diagnosis. Treatment usually consists of oral corticosteroids, although if a therapeutic response is not achieved, stronger immunosuppressive drugs may be necessary.A recent review found that 98% of patients with CS had hearing and/or vestibular symptoms. Of that group, bilateral hearing loss was present in 41% and deafness in 31%. For those patients who suffer unaidable hearing loss, cochlear implantation is necessary to restore sound. This disease process, however, can present challenges to the surgeon. A recent case series of cochlear implantation in CS revealed that half of these patients had ossification of the scala tympani during surgery (6 of 12 patients). Despite these findings, their population of CS implant recipients obtained an average word recognition score of 91% at one year of device use .Since cochlear abnormalities are frequent with CS, preoperative evaluation and planning are crucial to successful implantation surgery. This case demonstrated the severity of cochlear ossification that can occur in CS. This information is useful not only for surgical approach and device selection, but for preoperative counseling with the patient as well. Although the reported follow-up is of short duration (5 months) and there is potential for fluctuation in implant performance over time, she has consistently improved with her implants over time and is yet to observe any decreased performance at the time of writing this manuscript.