Endoscopic Versus Microscopic Stapedotomy: A Single-Blinded Randomized Control Trial.

OBJECTIVE: To demonstrate non-inferiority of endoscopic stapedotomy to microscopic stapedotomy for the treatment of otosclerosis. STUDY DESIGN: Single-blinded randomized control trial. SETTING: Tertiary, academic otology-neurotology practice. PATIENTS: Adult subjects with a diagnosis of otosclerosis and a preoperative air-bone gap (ABG) more than or equal to 20 dB undergoing primary stapedotomy. INTERVENTION: Endoscopic or microscopic stapedotomy. MAIN OUTCOME MEASURES: Primary audiometric outcome was postoperative ABG. Secondary audiometric outcomes included speech reception threshold (SRT), word recognition score (WRS), bone- and air-conduction pure tone averages (PTA), change in ABG, and ABG closure rates to less than or equal to 10 dB and less than or equal to 20 dB. RESULTS: Twenty-two patients were recruited. Eleven patients underwent endoscopic stapedotomy and 11 underwent microscopic stapedotomy. The endoscopic group was non-inferior to the microscopic group in terms of postoperative audiometric outcomes (endoscope versus microscope, p-value): ABG (8.1 dB versus 8.1 dB, <0.001), SRT (27.7 dB versus 25.9 dB, <0.001), WRS (92% at 65 dB versus 98% at 62 dB, <0.001), air-conduction PTA (33.5 dB versus 30.8 dB, <0.01), and change in ABG (23.0 dB versus 20.7 dB, <0.0001). ABG closure rates to less than or equal to 10 dB (72.7% versus 81.2%, p = 1.0) and less than or equal to 20 dB (90.9% versus 100%, p = 1.0) were not significantly different. There was no significant difference in operative time, necessity of scutum curettage, or postoperative dysgeusia. No patients required chorda tympani sacrifice. Preoperative tinnitus resolved in three patients in each group postoperatively. CONCLUSIONS: This study is the first randomized control trial to demonstrate non-inferiority of endoscopic to microscopic stapedotomy.

Chemical Interactions of Polyethylene Glycols (PEGs) and Glycerol with Protein Functional Groups: Applications to Effects of PEG and Glycerol on Protein Processes.

In this work, we obtain the data needed to predict chemical interactions of polyethylene glycols (PEGs) and glycerol with proteins and related organic compounds and thereby interpret or predict chemical effects of PEGs on protein processes. To accomplish this, we determine interactions of glycerol and tetraEG with >30 model compounds displaying the major C, N, and O functional groups of proteins. Analysis of these data yields coefficients (α values) that quantify interactions of glycerol, tetraEG, and PEG end (-CH2OH) and interior (-CH2OCH2-) groups with these groups, relative to interactions with water. TetraEG (strongly) and glycerol (weakly) interact favorably with aromatic C, amide N, and cationic N, but unfavorably with amide O, carboxylate O, and salt ions. Strongly unfavorable O and salt anion interactions help make both small and large PEGs effective protein precipitants. Interactions of tetraEG and PEG interior groups with aliphatic C are quite favorable, while interactions of glycerol and PEG end groups with aliphatic C are not. Hence, tetraEG and PEG300 favor unfolding of the DNA-binding domain of lac repressor (lacDBD), while glycerol and di- and monoethylene glycol are stabilizers. Favorable interactions with aromatic and aliphatic C explain why PEG400 greatly increases the solubility of aromatic hydrocarbons and steroids. PEG400-steroid interactions are unusually favorable, presumably because of simultaneous interactions of multiple PEG interior groups with the fused ring system of the steroid. Using α values reported here, chemical contributions to PEG m-values can be predicted or interpreted in terms of changes in water-accessible surface area (ΔASA) and separated from excluded volume effects.