Visualization and clinical relevance of the endolymphatic duct and sac in Ménière's disease.

Background: Ménière's disease (MD) is a chronic inner ear disorder with a multifactorial etiology. Decreased visualization of the endolymphatic duct (ED) and sac (ES) is thought to be associated with MD, although controversy exists about whether this finding is specific to MD. Recent literature has revealed that two distinct ES pathologies, developmental hypoplasia and epithelial degeneration, can be distinguished in MD using the angular trajectory of the vestibular aqueduct (ATVA) or ED-ES system as a radiographic surrogate marker. It has been suggested that these two subtypes are associated with distinct phenotypical features. However, the clinical differences between the ATVA subtypes require further validation. Research objective: The objective of this study is to investigate whether (1) non-visualization of the ED-ES system is a discriminative radiological feature for MD in a cohort of vertigo-associated pathologies (VAPs) and whether (2) different angular trajectories of the ED-ES system in MD are associated with distinguishable clinical features. Setting: The study was conducted in the Vertigo Referral Center (Haga Teaching Hospital, The Hague, the Netherlands). Methods: We retrospectively assessed 301 patients (187 definite MD and 114 other VAPs) that underwent 4h-delayed 3D FLAIR MRI. We evaluated (1) the visibility of the ED-ES system between MD and other VAP patients and (2) measured the angular trajectory of the ED-ES system. MD patients were stratified based on the angular measurements into αexit ≤ 120° (MD-120), αexit 120°-140° (MD-intermediate), or αexit ≥ 140° (MD-140). Correlations between ATVA subgroups and clinical parameters were evaluated. Results: Non-visualization of the ED-ES system was more common in definite MD patients compared with other VAPs (P < 0.001). Among definite MD patients, the MD-140 subtype demonstrated a longer history of vertigo (P = 0.006), a higher prevalence of bilateral clinical disease (P = 0.005), and a trend toward a male preponderance (p = 0.053). No significant differences were found between ATVA subgroups regarding the presence or severity of auditory symptoms, or the frequency of vertigo attacks. Conclusion: Non-visualization of the ED-ES system is significantly associated with MD. Among MD patients with a visible ED-ES system, we demonstrated that the MD-140 subtype is associated with a longer disease duration, a higher prevalence of bilateral MD, and a trend toward a male preponderance.

Quality of life after intratympanic steroid injection for Ménière's disease.

Objective: This study explores how treatment with intratympanic steroid injection affects quality of life, as well as several subjective complaints in patients with Ménière's disease. Methods: Patients filled in the Ménière's Disease Outcome Questionnaire (MDOQ) and answered questions about subjective complaints. Scores before and after treatment were compared using paired t tests. Results: Forty-nine patients treated with intratympanic steroid injection were included. Quality of life was improved in 36 (73%) patients, the same in 9 (18%) patients, and lower in 4 (8%) patients. Overall, the mean change in MDOQ was +20.6 points (95% confidence interval +14.5 to +26.7 points, p < 0.001). The improvement was seen in the emotional, physical, and mental domain. Most patients experienced less vertigo and instability but did not notice change in subjective hearing, tinnitus, or aural fullness after treatment. Conclusion: Treatment with intratympanic steroid injection leads to an improvement in quality of life in most patients. Moreover, the procedure is only minimally invasive. Based on the findings in this study, treatment with ITS should be discussed with every patient suffering from vertigo attacks due to active Ménière's disease. Level of evidence: Level 4.

Hydropic Ear Disease: Correlation Between Audiovestibular Symptoms, Endolymphatic Hydrops and Blood-Labyrinth Barrier Impairment.

Research Objective: To investigate the correlation between clinical features and MRI-confirmed endolymphatic hydrops (EH) and blood-labyrinth barrier (BLB) impairment. Study Design: Retrospective cross-sectional study. Setting: Vertigo referral center (Haga Teaching Hospital, The Hague, the Netherlands). Methods: We retrospectively analyzed all patients that underwent 4 h-delayed Gd-enhanced 3D FLAIR MRI at our institution from February 2017 to March 2019. Perilymphatic enhancement and the degree of cochlear and vestibular hydrops were assessed. The signal intensity ratio (SIR) was calculated by region of interest analysis. Correlations between MRI findings and clinical features were evaluated. Results: Two hundred and fifteen patients with MRI-proven endolymphatic hydrops (EH) were included (179 unilateral, 36 bilateral) with a mean age of 55.9 yrs and median disease duration of 4.3 yrs. Hydrops grade is significantly correlated with disease duration (P < 0.001), the severity of low- and high-frequency hearing loss (both P < 0.001), and the incidence of drop attacks (P = 0.001). Visually increased perilymphatic enhancement was present in 157 (87.7%) subjects with unilateral EH. SIR increases in correlation with hydrops grade (P < 0.001), but is not significantly correlated with the low or high Fletcher index (P = 0.344 and P = 0.178 respectively). No significant differences were found between the degree of EH or BLB impairment and vertigo, tinnitus or aural fullness. Conclusion: The degree of EH positively correlates with disease duration, hearing loss and the incidence of drop attacks. The BLB is impaired in association with EH grade, but without clear contribution to the severity of audiovestibular symptoms.

Septorhinoplasty and Septoplasty: Outcomes of a Large Cohort Using Autologous Versus Homologous Cartilage, 1999-2019.

This study describes the complication rate and use of autologous and/or homologous cartilage in a large 20-year cohort of septo(rhino)plasty surgeries in a Dutch hospital, in relation to postoperative complications of septo(rhino)plasty surgery described in previous studies. A retrospective medical chart review was conducted. 2606 patients, mean age 34.7 (± 13.2) and 59.9% male, underwent primary or revision septo(rhino)plasty surgery from 01/01/1999 to 01/09/2019. Follow-up was known in 1384 of 2606 patients (53.1%) with a mean duration of 47.5 months. Complication registration was complete for 1774 patients. The overall complication rate was 270 out of 1774 (15.2%). The use of autologous costal cartilage (ACC) was a risk factor for overall complication with an odds ratio (OR) of 11.1 (95% CI 0.03-0.30; P < 0.01) as compared to 5.9 (95% CI 0.06-0.45; P < 0.01) when using homologous costal cartilage (HCC). Infections were more likely when ACC (5/26 [19.2%]) was used than when HCC (1/28 [3.6%]) was used. Notable resorption of cartilage was more likely when HCC (9/28 [32.1%]) was used than when ACC (1/26 [3.8%]) was used. Both the use of autologous costal cartilage grafts (OR 11.1) and homologous costal cartilage grafts (OR 5.9) lead to an increased risk of complications. When choosing cartilage type for reconstruction in septo(rhino)plasty, it should be taken into account that both ACC and HCC are associated with a higher risk of complications. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The ubiquitin-associated (UBA) domain of SCCRO/DCUN1D1 protein serves as a feedback regulator of biochemical and oncogenic activity.

Amplification of squamous cell carcinoma-related oncogene (SCCRO) activates its function as an oncogene in a wide range of human cancers. The oncogenic activity of SCCRO requires its potentiating neddylation domain, which regulates its E3 activity for neddylation. The contribution of the N-terminal ubiquitin-associated (UBA) domain to SCCRO function remains to be defined. We found that the UBA domain of SCCRO preferentially binds to polyubiquitin chains in a linkage-independent manner. Binding of polyubiquitin chains to the UBA domain inhibits the neddylation activity of SCCRO in vivo by inhibiting SCCRO-promoted nuclear translocation of neddylation components and results in a corresponding decrease in cullin-RING-ligase-promoted ubiquitination. The results of colony formation and xenograft assays showed a mutation in the UBA domain of SCCRO that reduces binding to polyubiquitin chains, significantly enhancing its oncogenic activity. Analysis of 47 lung and head and neck squamous cell carcinomas identified a case with a frameshift mutation in SCCRO that putatively codes for a protein that lacks a UBA domain. Analysis of data from The Cancer Genome Atlas showed that recurrent mutations cluster in the UBA domains of SCCRO, lose the ability to bind to polyubiquitinated proteins, and have increased neddylation and transformation activities. Combined, these data suggest that the UBA domain functions as a negative regulator of SCCRO function. Mutations in the UBA domain lead to loss of inhibitory control, which results in increased biochemical and oncogenic activity. The clustering of mutations in the UBA domain of SCCRO suggests that mutations may be a mechanism of oncogene activation in human cancers.

SCCRO3 (DCUN1D3) antagonizes the neddylation and oncogenic activity of SCCRO (DCUN1D1).

The activity of cullin-RING type ubiquitination E3 ligases is regulated by neddylation, a process analogous to ubiquitination that culminates in covalent attachment of the ubiquitin-like protein Nedd8 to cullins. As a component of the E3 for neddylation, SCCRO/DCUN1D1 plays a key regulatory role in neddylation and, consequently, cullin-RING ligase activity. The essential contribution of SCCRO to neddylation is to promote nuclear translocation of the cullin-ROC1 complex. The presence of a myristoyl sequence in SCCRO3, one of four SCCRO paralogues present in humans that localizes to the membrane, raises questions about its function in neddylation. We found that although SCCRO3 binds to CAND1, cullins, and ROC1, it does not efficiently bind to Ubc12, promote cullin neddylation, or conform to the reaction processivity paradigms, suggesting that SCCRO3 does not have E3 activity. Expression of SCCRO3 inhibits SCCRO-promoted neddylation by sequestering cullins to the membrane, thereby blocking its nuclear translocation. Moreover, SCCRO3 inhibits SCCRO transforming activity. The inhibitory effects of SCCRO3 on SCCRO-promoted neddylation and transformation require both an intact myristoyl sequence and PONY domain, confirming that membrane localization and binding to cullins are required for in vivo functions. Taken together, our findings suggest that SCCRO3 functions as a tumor suppressor by antagonizing the neddylation activity of SCCRO.

Oncogenic function of SCCRO5/DCUN1D5 requires its Neddylation E3 activity and nuclear localization.

PURPOSE: To determine mechanisms by which SCCRO5 (aka DCUN1D5) promotes oncogenesis. EXPERIMENTAL DESIGN: SCCRO5 mRNA and protein expression were assessed in 203 randomly selected primary cancer tissue samples, matched histologically normal tissues, and cell lines by use of real-time PCR and Western blot analysis. SCCRO5 overexpression was correlated with survival. The effect of SCCRO5 knockdown on viability was assessed in selected cancer cell lines. Structure-function studies were performed to determine the SCCRO5 residues required for binding to the neddylation components, for neddylation-promoting activity, and for transformation. RESULTS: In oral and lung squamous cell carcinomas, SCCRO5 mRNA levels corresponded with protein levels and overexpression correlated with decreased disease-specific survival. Knockdown of SCCRO5 by RNAi resulted in a selective decrease in the viability of cancer cells with high endogenous levels, suggesting the presence of oncogene addiction. SCCRO5 promoted cullin neddylation while maintaining conserved reaction processivity paradigms involved in ubiquitin and ubiquitin-like protein conjugation, establishing it as a component of the neddylation E3. Neddylation activities in vitro required the potentiating of neddylation (PONY) domain but not the nuclear localization sequence (NLS) domain. In contrast, both the NLS domain and the PONY domain were required for transformation of NIH-3T3 cells. CONCLUSIONS: Our data suggest that SCCRO5 has oncogenic potential that requires its function as a component of the neddylation E3. Neddylation activity and nuclear localization of SCCRO5 are important for its in vivo function.

REM-associated nasal obstruction: a study with acoustic rhinometry during sleep.

OBJECTIVE: Obstructive sleep apnea events are more common in REM sleep, although there is no relationship between sleep phase and pharyngeal airway status. We studied the patency of the nasal airway during REM and non-REM sleep with the use of acoustic rhinometry. METHODS: Serial acoustic rhinometric assessment of nasal cross-sectional area was performed in 10 subjects, before sleep and during REM and non-REM sleep. All measurements were standardized to a decongested baseline with mean congestion factor (MCF). RESULTS: MCF in the seated position was 10.6% (+/-3.7) and increased with supine positioning to 16.2% (+/-2.3). In REM sleep, MCF was highest, at 22.3% (+/-1.7). In non-REM sleep, MCF was lowest, at 2.3% (+/-3.1). All interstage comparisons were statistically significant on repeated measures ANOVA (P < 0.05). CONCLUSION: REM sleep is characterized by significant nasal congestion; non-REM sleep, by profound decongestion. This phenomenon may be attributable to REM-dependent variation in cerebral blood flow that affects nasal congestion via the internal carotid system. REM-induced nasal congestion, an indirect effect of augmented cerebral perfusion, may contribute to the higher frequency of obstructive events in REM sleep.

SCCRO (DCUN1D1) is an essential component of the E3 complex for neddylation.

Covalent modification of cullins by the ubiquitin-like protein NEDD8 (neddylation) regulates protein ubiquitination by promoting the assembly of cullin-RING ligase E3 complexes. Like ubiquitination, neddylation results from an enzymatic cascade involving the sequential activity of a dedicated E1 (APPBP1/Uba3), E2 (Ubc12), and an ill-defined E3. We show that SCCRO (also known as DCUN1D1) binds to the components of the neddylation pathway (Cullin-ROC1, Ubc12, and CAND1) and augments but is not required for cullin neddylation in reactions using purified recombinant proteins. We also show that SCCRO recruits Ubc12 approximately NEDD8 to the CAND1-Cul1-ROC1 complex but that this is not sufficient to dissociate or overcome the inhibitory effects of CAND1 on cullin neddylation in purified protein assays. In contrast to findings in cellular systems where no binding is seen, we show that SCCRO and CAND1 can bind to the neddylated Cul1-ROC1 complex in assays using purified recombinant proteins. Although neddylated (not unneddylated) Cul1-ROC1 is released from CAND1 upon incubation with testis lysate from SCCRO+/+ mice, the addition of recombinant SCCRO is required to achieve the same results in lysate from SCCRO(-/-) mice. Combined, these results suggest that SCCRO is an important component of the neddylation E3 complex that functions to recruit charged E2 and is involved in the release of inhibitory effects of CAND1 on cullin-RING ligase E3 complex assembly and activity.